[v2,4/4] thermal: k3_j72xx_bandgap: Add the bandgap driver support

Commit Message

J, KEERTHY Oct. 19, 2021, 4:06 p.m. UTC

Add VTM thermal support. In the Voltage Thermal Management
Module(VTM), K3 J72XX supplies a voltage reference and a temperature
sensor feature that are gathered in the band gap voltage and
temperature sensor (VBGAPTS) module. The band gap provides current and
voltage reference for its internal circuits and other analog IP
blocks. The analog-to-digital converter (ADC) produces an output value
that is proportional to the silicon temperature.

Currently reading temperatures only is supported.  There are no
active/passive cooling agent supported.

J721e SoCs have errata i2128: https://www.ti.com/lit/pdf/sprz455

The VTM Temperature Monitors (TEMPSENSORs) are trimmed during production,
with the resulting values stored in software-readable registers. Software
should use these  register values when translating the Temperature
Monitor output codes to temperature values.

It has an involved workaround. Software needs to read the error codes for
-40C, 30C, 125C from the efuse for each device & derive a new look up table
for adc to temperature conversion. Involved calculating slopes & constants
using 3 different straight line equations with adc refernce codes as the
y-axis & error codes in the x-axis.

-40C to 30C
30C to 125C
125C to 150C

With the above 2 line equations we derive the full look-up table to
workaround the errata i2128 for j721e SoC.

Tested temperature reading on J721e SoC & J7200 SoC.

Signed-off-by: Keerthy <[e-mail]>
---
 drivers/thermal/Makefile           |   2 +-
 drivers/thermal/k3_j72xx_bandgap.c | 772 +++++++++++++++++++++++++++++
 2 files changed, 773 insertions(+), 1 deletion(-)
 create mode 100644 drivers/thermal/k3_j72xx_bandgap.c

Comments

Daniel Lezcano Oct. 19, 2021, 6:03 p.m. UTC | #1

Hi Keerthy,


On 19/10/2021 18:06, Keerthy wrote:
> Add VTM thermal support. In the Voltage Thermal Management
> Module(VTM), K3 J72XX supplies a voltage reference and a temperature
> sensor feature that are gathered in the band gap voltage and
> temperature sensor (VBGAPTS) module. The band gap provides current and
> voltage reference for its internal circuits and other analog IP
> blocks. The analog-to-digital converter (ADC) produces an output value
> that is proportional to the silicon temperature.
> 
> Currently reading temperatures only is supported.  There are no
> active/passive cooling agent supported.
> 
> J721e SoCs have errata i2128: https://www.ti.com/lit/pdf/sprz455
> 
> The VTM Temperature Monitors (TEMPSENSORs) are trimmed during production,
> with the resulting values stored in software-readable registers. Software
> should use these  register values when translating the Temperature
> Monitor output codes to temperature values.
> 
> It has an involved workaround. Software needs to read the error codes for
> -40C, 30C, 125C from the efuse for each device & derive a new look up table
> for adc to temperature conversion. Involved calculating slopes & constants
> using 3 different straight line equations with adc refernce codes as the
> y-axis & error codes in the x-axis.
> 
> -40C to 30C
> 30C to 125C
> 125C to 150C
> 
> With the above 2 line equations we derive the full look-up table to
> workaround the errata i2128 for j721e SoC.
> 
> Tested temperature reading on J721e SoC & J7200 SoC.

I take some the time to trace the values in the array below and it
results in a very nice curve, almost flat.

That make me think the values are generated from a polynomial equation
like the other driver.

So instead of adding a full blob of array here which are 8KB in total in
this file, why not generate the array dynamically at probe time ?

That will save space on disk and memory.



> Signed-off-by: Keerthy <[e-mail]>
> ---
>  drivers/thermal/Makefile           |   2 +-
>  drivers/thermal/k3_j72xx_bandgap.c | 772 +++++++++++++++++++++++++++++
>  2 files changed, 773 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/thermal/k3_j72xx_bandgap.c
> 
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 82fc3e616e54..6dcaf2028ddc 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -28,7 +28,7 @@ thermal_sys-$(CONFIG_CPU_IDLE_THERMAL)	+= cpuidle_cooling.o
>  # devfreq cooling
>  thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
>  
> -obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o
> +obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o k3_j72xx_bandgap.o
>  # platform thermal drivers
>  obj-y				+= broadcom/
>  obj-$(CONFIG_THERMAL_MMIO)		+= thermal_mmio.o
> diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
> new file mode 100644
> index 000000000000..1aa048221291
> --- /dev/null
> +++ b/drivers/thermal/k3_j72xx_bandgap.c
> @@ -0,0 +1,772 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TI Bandgap temperature sensor driver for J72XX SoC Family
> + *
> + * Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com/
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/err.h>
> +#include <linux/types.h>
> +#include <linux/spinlock.h>
> +#include <linux/of_platform.h>
> +#include <linux/io.h>
> +#include <linux/thermal.h>
> +#include <linux/of.h>
> +#include <linux/delay.h>
> +
> +#define K3_VTM_DEVINFO_PWR0_OFFSET		0x4
> +#define K3_VTM_DEVINFO_PWR0_CVD_CT_MASK		0xf
> +#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK	0xf0
> +#define K3_VTM_TMPSENS0_CTRL_OFFSET		0x300
> +#define K3_VTM_MISC_CTRL_OFFSET			0xc
> +#define K3_VTM_TMPSENS_STAT_OFFSET		0x8
> +#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN		0x1
> +#define K3_VTM_MISC_CTRL2_OFFSET		0x10
> +#define K3_VTM_REGS_PER_TS			0x10
> +#define K3_VTM_TS_STAT_DTEMP_MASK		0x3ff
> +#define K3_VTM_MAX_NUM_TS			8
> +#define K3_VTM_TMPSENS_CTRL_CBIASSEL		BIT(0)
> +#define K3_VTM_TMPSENS_CTRL_SOC			BIT(5)
> +#define K3_VTM_TMPSENS_CTRL_CLRZ		BIT(6)
> +#define K3_VTM_TMPSENS_CTRL_CLKON_REQ		BIT(7)
> +#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN	BIT(11)
> +
> +#define K3_VTM_CORRECTION_TEMP_CNT		3
> +
> +#define K3_VTM_ADC_BEGIN_VAL			6
> +#define K3_VTM_ADC_END_VAL			944
> +
> +#define MINUS40CREF				5
> +#define PLUS30CREF				253
> +#define PLUS125CREF				730
> +#define PLUS150CREF				940
> +
> +#define MAX_TEMP				123000
> +#define COOL_DOWN_TEMP				105000
> +
> +//#define DEBUG_VTM
> +
> +static int derived_array[1024];
> +
> +/* Reference Look up table when work around is NOT needed */
> +static const int pvt_poly_golden[] = {
> +	-49002, -48677, -48352, -48028, -47704, -47381, -47057, -46734, -46412,
> +	-46090, -45768, -45446, -45125, -44804, -44484, -44163, -43844, -43524,
> +	-43205, -42886, -42567, -42249, -41931, -41614, -41297, -40980, -40663,
> +	-40347, -40031, -39716, -39400, -39085, -38771, -38457, -38143, -37829,
> +	-37516, -37203, -36890, -36578, -36266, -35955, -35643, -35332, -35022,
> +	-34712, -34402, -34092, -33783, -33474, -33165, -32857, -32549, -32241,
> +	-31934, -31626, -31320, -31013, -30707, -30401, -30096, -29791, -29486,
> +	-29182, -28877, -28573, -28270, -27967, -27664, -27361, -27059, -26757,
> +	-26455, -26154, -25853, -25552, -25252, -24952, -24652, -24353, -24054,
> +	-23755, -23456, -23158, -22860, -22563, -22265, -21968, -21672, -21376,
> +	-21079, -20784, -20488, -20193, -19899, -19604, -19310, -19016, -18723,
> +	-18429, -18136, -17844, -17551, -17259, -16968, -16676, -16385, -16094,
> +	-15804, -15514, -15224, -14934, -14645, -14356, -14067, -13779, -13491,
> +	-13203, -12916, -12628, -12342, -12055, -11769, -11483, -11197, -10912,
> +	-10627, -10342, -10057, -9773, -9489, -9206, -8922, -8639, -8357, -8074,
> +	-7792, -7510, -7229, -6947, -6666, -6386, -6105, -5825, -5546, -5266,
> +	-4987, -4708, -4429, -4151, -3873, -3595, -3318, -3041, -2764, -2487,
> +	-2211, -1935, -1659, -1384, -1108, -834, -559, -285, -11, 263, 537, 810,
> +	1083, 1355, 1628, 1900, 2171, 2443, 2714, 2985, 3255, 3526, 3796, 4066,
> +	4335, 4604, 4873, 5142, 5410, 5679, 5946, 6214, 6481, 6748, 7015, 7281,
> +	7548, 7813, 8079, 8344, 8609, 8874, 9139, 9403, 9667, 9931, 10194,
> +	10457, 10720, 10983, 11245, 11507, 11769, 12030, 12292, 12553, 12813,
> +	13074, 13334, 13594, 13854, 14113, 14372, 14631, 14889, 15148, 15406,
> +	15664, 15921, 16178, 16435, 16692, 16948, 17205, 17461, 17716, 17972,
> +	18227, 18482, 18736, 18991, 19245, 19498, 19752, 20005, 20258, 20511,
> +	20764, 21016, 21268, 21520, 21771, 22022, 22273, 22524, 22774, 23025,
> +	23274, 23524, 23774, 24023, 24272, 24520, 24769, 25017, 25265, 25512,
> +	25760, 26007, 26254, 26500, 26747, 26993, 27239, 27484, 27730, 27975,
> +	28220, 28464, 28708, 28953, 29196, 29440, 29683, 29927, 30169, 30412,
> +	30654, 30896, 31138, 31380, 31621, 31862, 32103, 32344, 32584, 32824,
> +	33064, 33304, 33543, 33783, 34022, 34260, 34499, 34737, 34975, 35213,
> +	35450, 35687, 35924, 36161, 36397, 36634, 36870, 37105, 37341, 37576,
> +	37811, 38046, 38281, 38515, 38749, 38983, 39217, 39450, 39683, 39916,
> +	40149, 40381, 40614, 40846, 41077, 41309, 41540, 41771, 42002, 42233,
> +	42463, 42693, 42923, 43153, 43382, 43611, 43840, 44069, 44297, 44526,
> +	44754, 44981, 45209, 45436, 45663, 45890, 46117, 46343, 46570, 46796,
> +	47021, 47247, 47472, 47697, 47922, 48147, 48371, 48595, 48819, 49043,
> +	49266, 49490, 49713, 49935, 50158, 50380, 50603, 50824, 51046, 51268,
> +	51489, 51710, 51931, 52151, 52372, 52592, 52812, 53031, 53251, 53470,
> +	53689, 53908, 54127, 54345, 54563, 54781, 54999, 55217, 55434, 55651,
> +	55868, 56085, 56301, 56517, 56733, 56949, 57165, 57380, 57595, 57810,
> +	58025, 58239, 58454, 58668, 58882, 59095, 59309, 59522, 59735, 59948,
> +	60160, 60373, 60585, 60797, 61009, 61220, 61432, 61643, 61854, 62064,
> +	62275, 62485, 62695, 62905, 63115, 63324, 63534, 63743, 63952, 64160,
> +	64369, 64577, 64785, 64993, 65200, 65408, 65615, 65822, 66029, 66236,
> +	66442, 66648, 66854, 67060, 67266, 67471, 67676, 67881, 68086, 68291,
> +	68495, 68699, 68903, 69107, 69311, 69514, 69717, 69920, 70123, 70326,
> +	70528, 70730, 70932, 71134, 71336, 71537, 71738, 71939, 72140, 72341,
> +	72541, 72742, 72942, 73142, 73341, 73541, 73740, 73939, 74138, 74337,
> +	74535, 74733, 74932, 75130, 75327, 75525, 75722, 75919, 76116, 76313,
> +	76510, 76706, 76902, 77098, 77294, 77490, 77685, 77881, 78076, 78271,
> +	78465, 78660, 78854, 79048, 79242, 79436, 79630, 79823, 80016, 80210,
> +	80402, 80595, 80788, 80980, 81172, 81364, 81556, 81747, 81939, 82130,
> +	82321, 82512, 82702, 82893, 83083, 83273, 83463, 83653, 83843, 84032,
> +	84221, 84410, 84599, 84788, 84976, 85165, 85353, 85541, 85728, 85916,
> +	86103, 86291, 86478, 86665, 86851, 87038, 87224, 87411, 87597, 87782,
> +	87968, 88154, 88339, 88524, 88709, 88894, 89078, 89263, 89447, 89631,
> +	89815, 89999, 90182, 90366, 90549, 90732, 90915, 91098, 91280, 91463,
> +	91645, 91827, 92009, 92191, 92372, 92554, 92735, 92916, 93097, 93277,
> +	93458, 93638, 93818, 93998, 94178, 94358, 94537, 94717, 94896, 95075,
> +	95254, 95433, 95611, 95790, 95968, 96146, 96324, 96501, 96679, 96856,
> +	97033, 97211, 97387, 97564, 97741, 97917, 98093, 98269, 98445, 98621,
> +	98797, 98972, 99147, 99322, 99497, 99672, 99847, 100021, 100196, 100370,
> +	100544, 100718, 100891, 101065, 101238, 101411, 101584, 101757, 101930,
> +	102103, 102275, 102447, 102619, 102791, 102963, 103135, 103306, 103478,
> +	103649, 103820, 103991, 104161, 104332, 104502, 104673, 104843, 105013,
> +	105182, 105352, 105522, 105691, 105860, 106029, 106198, 106367, 106535,
> +	106704, 106872, 107040, 107208, 107376, 107544, 107711, 107878, 108046,
> +	108213, 108380, 108546, 108713, 108880, 109046, 109212, 109378, 109544,
> +	109710, 109875, 110041, 110206, 110371, 110536, 110701, 110866, 111030,
> +	111195, 111359, 111523, 111687, 111851, 112015, 112178, 112342, 112505,
> +	112668, 112831, 112994, 113157, 113319, 113482, 113644, 113806, 113968,
> +	114130, 114292, 114453, 114615, 114776, 114937, 115098, 115259, 115420,
> +	115580, 115741, 115901, 116061, 116221, 116381, 116541, 116701, 116860,
> +	117019, 117179, 117338, 117497, 117655, 117814, 117973, 118131, 118289,
> +	118447, 118605, 118763, 118921, 119078, 119236, 119393, 119550, 119707,
> +	119864, 120021, 120178, 120334, 120490, 120647, 120803, 120959, 121115,
> +	121270, 121426, 121581, 121737, 121892, 122047, 122202, 122356, 122511,
> +	122666, 122820, 122974, 123128, 123282, 123436, 123590, 123744, 123897,
> +	124050, 124204, 124357, 124510, 124662, 124815, 124968, 125120, 125273,
> +	125425, 125577, 125729, 125881, 126032, 126184, 126335, 126487, 126638,
> +	126789, 126940, 127091, 127241, 127392, 127542, 127693, 127843, 127993,
> +	128143, 128293, 128442, 128592, 128741, 128891, 129040, 129189, 129338,
> +	129487, 129635, 129784, 129932, 130081, 130229, 130377, 130525, 130673,
> +	130821, 130968, 131116, 131263, 131410, 131558, 131705, 131851, 131998,
> +	132145, 132291, 132438, 132584, 132730, 132876, 133022, 133168, 133314,
> +	133460, 133605, 133750, 133896, 134041, 134186, 134331, 134476, 134620,
> +	134765, 134909, 135054, 135198, 135342, 135486, 135630, 135773, 135917,
> +	136061, 136204, 136347, 136491, 136634, 136777, 136919, 137062, 137205,
> +	137347, 137490, 137632, 137774, 137916, 138058, 138200, 138342, 138483,
> +	138625, 138766, 138907, 139049, 139190, 139331, 139471, 139612, 139753,
> +	139893, 140034, 140174, 140314, 140454, 140594, 140734, 140874, 141013,
> +	141153, 141292, 141432, 141571, 141710, 141849, 141988, 142127, 142265,
> +	142404, 142542, 142681, 142819, 142957, 143095, 143233, 143371, 143509,
> +	143646, 143784, 143921, 144058, 144196, 144333, 144470, 144607, 144743,
> +	144880, 145017, 145153, 145289, 145426, 145562, 145698, 145834, 145970,
> +	146105, 146241, 146377, 146512, 146647, 146783, 146918, 147053, 147188,
> +	147323, 147457, 147592, 147727, 147861, 147995, 148130, 148264, 148398,
> +	148532, 148666, 148799, 148933, 149067, 149200, 149333, 149467, 149600,
> +	149733, 149866, 149999, 150131, 150264, 150397, 150529, 150661, 150794,
> +	150926, 151058, 151190, 151322, 151454, 151585, 151717, 151848, 151980,
> +	152111,	152242, 152373, 152505, 152635, 152766, 152897, 153028, 153158,
> +	153289, 153419, 153549, 153680, 153810, 153940, 154070, 154199, 154329,
> +	154459, 154588, 154718, 154847, 154976, 155105, 155235, 155363, 155492,
> +	155621, 155750, 155879, 156007, 156135, 156264, 156392, 156520, 156648,
> +	156776, 156904, 157032, 157160, 157287, 157415, 157542, 157670, 157797,
> +	157924, 158051, 158178, 158305, 158432, 158559, 158685, 158812, 158938,
> +	159065, 159191, 159317, 159443, 159569,
> +};
> +
> +/* Reference Look up table when work around is needed */
> +static const int pvt_poly[] = {
> +	-41523, -41210, -40898, -40586, -40274, -39963, -39651, -39340,	-39029,
> +	-38718, -38408, -38098, -37788, -37478, -37168, -36859, -36550, -36241,
> +	-35933, -35624, -35316, -35008, -34701, -34393, -34086, -33779, -33472,
> +	-33166, -32859, -32553, -32247, -31942, -31636, -31331, -31026, -30722,
> +	-30417, -30113, -29809, -29505, -29202, -28899, -28596, -28293, -27990,
> +	-27688, -27386, -27084, -26782, -26481, -26179, -25878, -25578, -25277,
> +	-24977, -24677, -24377, -24078, -23778, -23479, -23180, -22882, -22583,
> +	-22285, -21987, -21689, -21392, -21095, -20797, -20501, -20204, -19908,
> +	-19612, -19316, -19020, -18725, -18430, -18135, -17840, -17545, -17251,
> +	-16957, -16663, -16370, -16077, -15783, -15491, -15198,	-14906, -14613,
> +	-14321, -14030, -13738, -13447, -13156, -12865, -12575, -12284, -11994,
> +	-11704, -11415, -11125, -10836, -10547, -10259, -9970, -9682, -9394,
> +	-9106, -8819, -8531, -8244, -7957, -7671, -7384, -7098, -6812, -6527,
> +	-6241, -5956, -5671, -5386, -5102, -4817, -4533, -4250, -3966, -3683,
> +	-3399, -3117, -2834, -2551, -2269, -1987, -1706, -1424, -1143, -862,
> +	-581, -300, -20, 260, 540, 820, 1099, 1378, 1657, 1936, 2215, 2493,
> +	2771, 3049, 3326, 3604, 3881, 4158, 4434, 4711, 4987, 5263, 5539, 5814,
> +	6089, 6364, 6639, 6914, 7188, 7462, 7736, 8010, 8283, 8556, 8829, 9102,
> +	9374, 9647, 9919, 10191, 10462, 10733, 11005, 11275, 11546, 11816,
> +	12087, 12357, 12626, 12896, 13165, 13434, 13703, 13971, 14240, 14508,
> +	14776, 15043, 15311, 15578, 15845, 16111, 16378, 16644, 16910, 17176,
> +	17441, 17707, 17972, 18237, 18501, 18766, 19030, 19294, 19557, 19821,
> +	20084, 20347, 20610, 20872, 21135, 21397, 21658, 21920, 22181, 22443,
> +	22703, 22964, 23225, 23485, 23745, 24005, 24264, 24523, 24782, 25041,
> +	25300, 25558, 25816, 26074, 26332, 26589, 26846, 27103, 27360, 27617,
> +	27873, 28129, 28385, 28640, 28896, 29151, 29406, 29660, 29915, 30169,
> +	30423, 30677, 30930, 31183, 31437, 31689, 31942, 32194, 32446, 32698,
> +	32950, 33201, 33452, 33703, 33954, 34205, 34455, 34705, 34955, 35204,
> +	35454, 35703, 35952, 36200, 36449, 36697, 36945, 37192, 37440, 37687,
> +	37934, 38181, 38427, 38674, 38920, 39166, 39411, 39657, 39902, 40147,
> +	40391, 40636, 40880, 41124, 41368, 41611, 41855, 42098, 42341, 42583,
> +	42826, 43068, 43310, 43551, 43793, 44034, 44275, 44516, 44756, 44997,
> +	45237, 45477, 45716, 45956, 46195, 46434, 46672, 46911, 47149, 47387,
> +	47625, 47862, 48100, 48337, 48573, 48810, 49046, 49282, 49518, 49754,
> +	49989, 50225, 50460, 50694, 50929, 51163, 51397, 51631, 51865, 52098,
> +	52331, 52564, 52797, 53029, 53261, 53493, 53725, 53956, 54188, 54419,
> +	54650, 54880, 55110, 55341, 55570, 55800, 56030, 56259, 56488, 56716,
> +	56945, 57173, 57401, 57629, 57856, 58084, 58311, 58538, 58764, 58991,
> +	59217, 59443, 59669, 59894, 60119, 60344, 60569, 60794, 61018, 61242,
> +	61466, 61690, 61913, 62136, 62359, 62582, 62804, 63026, 63249, 63470,
> +	63692, 63913, 64134, 64355, 64576, 64796, 65016, 65236, 65456, 65675,
> +	65894, 66113, 66332, 66551, 66769, 66987, 67205, 67423, 67640, 67857,
> +	68074, 68291, 68507, 68723, 68939, 69155, 69371, 69586, 69801, 70016,
> +	70230, 70445, 70659, 70873, 71086, 71300, 71513, 71726, 71939, 72151,
> +	72364, 72576, 72787, 72999, 73210, 73422, 73632, 73843, 74053, 74264,
> +	74474, 74683, 74893, 75102, 75311, 75520, 75729, 75937, 76145, 76353,
> +	76561, 76768, 76975, 77182, 77389, 77595, 77802, 78008, 78213, 78419,
> +	78624, 78829, 79034, 79239, 79443, 79647, 79851, 80055, 80259, 80462,
> +	80665, 80868, 81070, 81273, 81475, 81676, 81878, 82079, 82281, 82482,
> +	82682, 82883, 83083, 83283, 83483, 83682, 83882, 84081, 84280, 84478,
> +	84677, 84875, 85073, 85270, 85468, 85665, 85862, 86059, 86255, 86452,
> +	86648, 86844, 87039, 87234, 87430, 87625, 87819, 88014, 88208, 88402,
> +	88596, 88789, 88982, 89175, 89368, 89561, 89753, 89945, 90137, 90329,
> +	90520, 90712, 90903, 91093, 91284, 91474, 91664, 91854, 92044, 92233,
> +	92422, 92611, 92800, 92988, 93176, 93364, 93552, 93739, 93927, 94114,
> +	94301, 94487, 94673, 94860, 95045, 95231, 95417, 95602, 95787, 95971,
> +	96156, 96340, 96524, 96708, 96892, 97075, 97258, 97441, 97624, 97806,
> +	97988, 98170, 98352, 98533, 98714, 98895, 99076, 99257, 99437, 99617,
> +	99797, 99977, 100156, 100335, 100514, 100693, 100871, 101050, 101228,
> +	101405, 101583, 101760, 101937, 102114, 102291, 102467, 102643, 102819,
> +	102995, 103170, 103346, 103521, 103695, 103870, 104044, 104218, 104392,
> +	104566, 104739, 104912, 105085, 105258, 105430, 105603, 105775, 105946,
> +	106118, 106289, 106460, 106631, 106802, 106972, 107142, 107312, 107482,
> +	107651, 107820, 107989, 108158, 108327, 108495, 108663, 108831, 108998,
> +	109166, 109333, 109500, 109666, 109833, 109999, 110165, 110331, 110496,
> +	110661, 110827, 110991, 111156, 111320, 111484, 111648, 111812, 111975,
> +	112139, 112301, 112464, 112627, 112789, 112951, 113113, 113274, 113436,
> +	113597, 113758, 113918, 114079, 114239, 114399, 114559, 114718, 114877,
> +	115036, 115195, 115354, 115512, 115670, 115828, 115986, 116143, 116300,
> +	116457, 116614, 116770, 116926, 117082, 117238, 117394, 117549, 117704,
> +	117859, 118014, 118168, 118322, 118476, 118630, 118783, 118937, 119090,
> +	119242, 119395, 119547, 119699, 119851, 120003, 120154, 120305, 120456,
> +	120607, 120757, 120907, 121057, 121207, 121357, 121506, 121655, 121804,
> +	121953, 122101, 122249, 122397, 122545, 122692, 122839, 122986, 123133,
> +	123280, 123426, 123572, 123718, 123863, 124009, 124154, 124299, 124443,
> +	124588, 124732, 124876, 125020, 125163, 125306, 125449, 125592, 125735,
> +	125877, 126019, 126161, 126303, 126444, 126585, 126726, 126867, 127008,
> +	127148, 127288, 127428, 127567, 127707, 127846, 127985, 128123, 128262,
> +	128400, 128538, 128676, 128813, 128950, 129087, 129224, 129361, 129497,
> +	129633, 129769, 129905, 130040, 130175, 130310, 130445, 130579, 130713,
> +	130847, 130981, 131115, 131248, 131381, 131514, 131647, 131779, 131911,
> +	132043, 132175, 132306, 132438, 132569, 132699, 132830, 132960, 133090,
> +	133220, 133350, 133479, 133608, 133737, 133866, 133994, 134123, 134251,
> +	134378, 134506, 134633, 134760, 134887, 135014, 135140, 135266, 135392,
> +	135518, 135643, 135768, 135893, 136018, 136143, 136267, 136391, 136515,
> +	136638, 136762, 136885, 137008, 137130, 137253, 137375, 137497, 137619,
> +	137740, 137862, 137983, 138103, 138224, 138344, 138464, 138584, 138704,
> +	138823, 138943, 139062, 139180, 139299, 139417, 139535, 139653, 139770,
> +	139888, 140005, 140122, 140238, 140355, 140471, 140587, 140703, 140818,
> +	140933, 141048, 141163, 141278, 141392, 141506, 141620, 141734, 141847,
> +	141960, 142073, 142186, 142298, 142411, 142523, 142634, 142746, 142857,
> +	142968, 143079, 143190, 143300, 143410, 143520, 143630, 143740, 143849,
> +	143958, 144067, 144175, 144283, 144391, 144499, 144607, 144714, 144821,
> +	144928, 145035, 145142, 145248, 145354, 145459, 145565, 145670, 145775,
> +	145880, 145985, 146089, 146193, 146297, 146401, 146504, 146608, 146711,
> +	146813, 146916, 147018, 147120, 147222, 147324, 147425, 147526, 147627,
> +	147728, 147828, 147928, 148028, 148128, 148228, 148327, 148426, 148525,
> +	148623, 148722, 148820, 148918, 149015, 149113, 149210, 149307, 149404,
> +	149500, 149596, 149692, 149788, 149884, 149979, 150074, 150169, 150264,
> +	150358, 150452, 150546, 150640, 150733, 150827, 150920, 151013, 151105,
> +	151197, 151290, 151381, 151473, 151564, 151656, 151747, 151837, 151928,
> +	152018, 152108, 152198, 152287, 152377, 152466, 152555, 152643, 152732,
> +	152820, 152908, 152995, 153083, 153170, 153257, 153344, 153430, 153517,
> +	153603, 153689, 153774, 153860, 153945, 154030, 154114, 154199, 154283,
> +	154367, 154451, 154534, 154618, 154701, 154784, 154866, 154949, 155031,
> +	155113, 155194, 155276, 155357, 155438, 155519, 155599, 155680, 155760,
> +	155839, 155919, 155998, 156078, 156156, 156235, 156314, 156392, 156470,
> +	156547, 156625, 156702, 156779, 156856, 156933, 157009, 157085, 157161,
> +};
> +
> +static void fill_table(int err1, int err2, int ref1, int ref2, int idx1,
> +		       int idx2)
> +{
> +	int m, c, num, den, i, err;
> +
> +	/**
> +	 * Calculate the slope with adc values read from the register
> +	 * as the y-axis param and err in adc value as x-axis param
> +	 */
> +	if (err1 != err2) {
> +		num = ref2 - ref1;
> +		den = err2 - err1;
> +		m = num / den;
> +		c = ref2 - m * err2;
> +		for (i = idx1; i <= idx2; i++) {
> +			err = (i - c) / m;
> +			if (((i + err1) < 0) || ((i + err1) > 1023))
> +				continue;
> +			derived_array[i] = pvt_poly[i + err];
> +		}
> +	} else { /* Constant error take care of divide by zero */
> +		for (i = idx1; i < idx2; i++) {
> +			if (((i + err1) < 0) || ((i + err1) > 1023))
> +				continue;
> +			derived_array[i] = pvt_poly[i + err1];
> +		}
> +	}
> +}
> +
> +static int prep_lookup_table(int minus40cerr, int plus30cerr, int plus125cerr,
> +			     int plus150cerr)
> +{
> +	int start_temp, inc, i;
> +
> +	/* Fill up the lookup table region -40C to +30C */
> +	fill_table(minus40cerr, plus30cerr, MINUS40CREF, PLUS30CREF, 0,
> +		   PLUS30CREF);
> +	/* Fill up the lookup table region +30C to +125C */
> +	fill_table(plus30cerr, plus125cerr, PLUS30CREF, PLUS125CREF, PLUS30CREF,
> +		   PLUS125CREF);
> +	/* Fill up the lookup table region +125C to +150C */
> +	fill_table(plus125cerr, plus150cerr, PLUS125CREF, PLUS150CREF, PLUS125CREF,
> +		   PLUS150CREF);
> +
> +	/* Get to the first valid temperature */
> +	i = 0;
> +	while (!derived_array[i])
> +		i++;
> +
> +	start_temp = i;
> +	/*
> +	 * Get to the last zero index and back fill the temperature for
> +	 * sake of continuity
> +	 */
> +	if (i) {
> +		/* 300 milli celsius steps */
> +		while (i--)
> +			derived_array[i] = derived_array[i + 1] - 300;
> +		/* case 0 */
> +		derived_array[i] = derived_array[i + 1] - 300;
> +	}
> +
> +	/*
> +	 * Fill the last trailing 0s which are unfilled with increments of
> +	 * 100 milli celsius till 1023 code
> +	 */
> +	i = 1023;
> +	while (!derived_array[i])
> +		i--;
> +
> +	i++;
> +	inc = 1;
> +	while (i < 1024) {
> +		derived_array[i] = derived_array[i - 1] + inc * 100;
> +		i++;
> +	}
> +
> +	return 0;
> +}
> +
> +struct k3_thermal_data;
> +
> +struct k3_j72xx_bandgap {
> +	struct device *dev;
> +	void __iomem *base;
> +	void __iomem *cfg2_base;
> +	void __iomem *fuse_base;
> +	const struct k3_j72xx_bandgap_data	*conf;
> +	spinlock_t lock; /* shields this struct */
> +	int ts_cnt;
> +	struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
> +};
> +
> +/* common data structures */
> +struct k3_thermal_data {
> +	struct thermal_zone_device *ti_thermal;
> +	struct thermal_cooling_device *cool_dev;
> +	struct k3_j72xx_bandgap *bgp;
> +	enum thermal_device_mode mode;
> +	int sensor_id;
> +	u32 ctrl_offset;
> +	u32 stat_offset;
> +	int prev_temp;
> +	int ct_offsets[K3_VTM_CORRECTION_TEMP_CNT];
> +	int ct_bm[K3_VTM_CORRECTION_TEMP_CNT];
> +	int ref_adc_val[3];
> +	int act_adc_val[3];
> +	int slope[2];
> +	int coeff[2];
> +};
> +
> +int two_cmp(int tmp, int mask)
> +{
> +	tmp = ~(tmp);
> +	tmp &= mask;
> +	tmp += 1;
> +
> +	/* Return negative value */
> +	return (0 - tmp);
> +}
> +
> +static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
> +				       unsigned int s2)
> +{
> +	int d01 = abs(s0 - s1);
> +	int d02 = abs(s0 - s2);
> +	int d12 = abs(s1 - s2);
> +
> +	if (d01 <= d02 && d01 <= d12)
> +		return (s0 + s1) / 2;
> +
> +	if (d02 <= d01 && d02 <= d12)
> +		return (s0 + s2) / 2;
> +
> +	return (s1 + s2) / 2;
> +}
> +
> +static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
> +				   int *temp)
> +{
> +	struct k3_j72xx_bandgap *bgp;
> +	unsigned int dtemp, s0, s1, s2;
> +
> +	bgp = devdata->bgp;
> +	/*
> +	 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There
> +	 * is a variation of the order for certain degree centigrade on AM654.
> +	 * Work around that by getting the average of two closest
> +	 * readings out of three readings everytime we want to
> +	 * report temperatures.
> +	 *
> +	 * Errata workaround.
> +	 */
> +	s0 = readl(bgp->base + devdata->stat_offset) &
> +		K3_VTM_TS_STAT_DTEMP_MASK;
> +	s1 = readl(bgp->base + devdata->stat_offset) &
> +		K3_VTM_TS_STAT_DTEMP_MASK;
> +	s2 = readl(bgp->base + devdata->stat_offset) &
> +		K3_VTM_TS_STAT_DTEMP_MASK;
> +	dtemp = vtm_get_best_value(s0, s1, s2);
> +
> +	if (dtemp < 0 || dtemp > 1023)
> +		return -EINVAL;
> +
> +	*temp = derived_array[dtemp];
> +
> +	return 0;
> +}
> +
> +/* Get temperature callback function for thermal zone */
> +static int k3_thermal_get_temp(void *devdata, int *temp)
> +{
> +	struct k3_thermal_data *data = devdata;
> +	int ret = 0;
> +
> +	ret = k3_bgp_read_temp(data, temp);
> +	if (ret)
> +		return ret;
> +
> +	data->prev_temp = *temp;
> +
> +	return ret;
> +}
> +
> +static const struct thermal_zone_of_device_ops k3_of_thermal_ops = {
> +	.get_temp = k3_thermal_get_temp,
> +};
> +
> +static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
> +{
> +	int low = 0, high = 1023, mid;
> +
> +	if (temp > 160000 || temp < -50000)
> +		return -EINVAL;
> +
> +	/* Binary search to find the adc code */
> +	while (low < (high - 1)) {
> +		mid = (low + high) / 2;
> +		if (temp <= derived_array[mid])
> +			high = mid;
> +		else
> +			low = mid;
> +	}
> +
> +	return mid;
> +}
> +
> +static void get_efuse_values(int id, struct k3_thermal_data *data, int *err,
> +			     struct k3_j72xx_bandgap *bgp)
> +{
> +	int i, tmp, pow;
> +
> +	/* Populate efuse reg offsets & Bit masks for -40C, 30C, 125C */
> +	switch (id) {
> +	case 0:
> +		data->ct_offsets[0] = 0x0;
> +		data->ct_offsets[1] = 0x8;
> +		data->ct_offsets[2] = 0x4;
> +		data->ct_bm[0] = 0x3f;
> +		data->ct_bm[1] = 0x1fe000;
> +		data->ct_bm[2] = 0x1ff;
> +		break;
> +
> +	case 1:
> +		data->ct_offsets[0] = 0x0;
> +		data->ct_offsets[1] = 0x8;
> +		data->ct_offsets[2] = 0x4;
> +		data->ct_bm[0] = 0xfc0;
> +		data->ct_bm[1] = 0x1fe00000;
> +		data->ct_bm[2] = 0x3fe00;
> +		break;
> +
> +	case 2:
> +		data->ct_offsets[0] = 0x0;
> +		data->ct_offsets[1] = -1;
> +		data->ct_offsets[2] = 0x4;
> +		data->ct_bm[0] = 0x3f000;
> +		data->ct_bm[1] = 0x7f800000;
> +		data->ct_bm[2] = 0x7fc0000;
> +		break;
> +
> +	case 3:
> +		data->ct_offsets[0] = 0x0;
> +		data->ct_offsets[1] = 0xC;
> +		data->ct_offsets[2] = -1; /* Spread across 2 registers */
> +		data->ct_bm[0] = 0xfc0000;
> +		data->ct_bm[1] = 0x1fe0;
> +		data->ct_bm[2] = 0x1f800000;
> +		break;
> +
> +	case 4:
> +		data->ct_offsets[0] = 0x0;
> +		data->ct_offsets[1] = 0xc;
> +		data->ct_offsets[2] = 0x8;
> +		data->ct_bm[0] = 0x3f000000;
> +		data->ct_bm[1] = 0x1fe000;
> +		data->ct_bm[2] = 0x1ff0;
> +		break;
> +	}
> +
> +	for (i = 0; i < 3; i++) {
> +		/* Extract the offset value using bit-mask */
> +		if (data->ct_offsets[i] == -1 && i == 1) {
> +			/* 25C offset Case of Sensor 2 split between 2 regs */
> +			tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29);
> +			tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3);
> +			pow = tmp & 0x80;
> +		} else if (data->ct_offsets[i] == -1 && i == 2) {
> +			/* 125C Case of Sensor 3 split between 2 regs */
> +			tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27);
> +			tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5);
> +			pow = tmp & 0x100;
> +		} else {
> +			tmp = readl(bgp->fuse_base + data->ct_offsets[i]);
> +			tmp &= data->ct_bm[i];
> +			tmp = tmp >> __ffs(data->ct_bm[i]);
> +
> +			/* Obtain the sign bit pow*/
> +			pow = data->ct_bm[i] >> __ffs(data->ct_bm[i]);
> +			pow += 1;
> +			pow /= 2;
> +		}
> +
> +		/* Check for negative value */
> +		if (tmp & pow) {
> +			/* 2's complement value */
> +			tmp = two_cmp(tmp, data->ct_bm[i] >> __ffs(data->ct_bm[i]));
> +		}
> +		err[i] = tmp;
> +	}
> +}
> +
> +#ifdef DEBUG_VTM
> +static void print_look_up_table(struct device *dev)
> +{
> +	int i;
> +
> +	dev_info(dev, "The contents of derived array\n");
> +	dev_info(dev, "Code   Temperaturei\n");
> +	for (i = 0; i <= 1023; i++)
> +		dev_info(dev, "%d       %d\n", i, derived_array[i]);
> +}
> +#endif
> +
> +static const struct of_device_id of_k3_j72xx_bandgap_match[];
> +
> +struct k3_j72xx_bandgap_j72xx_data {
> +	unsigned int	workaround;
> +};
> +
> +static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
> +{
> +	int ret = 0, cnt, val, id, reg_cnt = 0, j;
> +	int err[3], high_max, low_max;
> +	struct resource *res;
> +	struct device *dev = &pdev->dev;
> +	struct k3_j72xx_bandgap *bgp;
> +	struct k3_thermal_data *data;
> +	int workaround_needed = 0;
> +	const struct of_device_id *of_id;
> +	const struct k3_j72xx_bandgap_j72xx_data *driver_data;
> +
> +	bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
> +	if (!bgp)
> +		return -ENOMEM;
> +
> +	bgp->dev = dev;
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	bgp->base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(bgp->base))
> +		return PTR_ERR(bgp->base);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +	bgp->cfg2_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(bgp->cfg2_base))
> +		return PTR_ERR(bgp->cfg2_base);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
> +	bgp->fuse_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(bgp->fuse_base))
> +		return PTR_ERR(bgp->fuse_base);
> +
> +	of_id = of_match_device(of_k3_j72xx_bandgap_match, &pdev->dev);
> +	if (of_id) {
> +		driver_data = of_id->data;
> +		workaround_needed = driver_data->workaround;
> +	}
> +
> +	pm_runtime_enable(dev);
> +	ret = pm_runtime_get_sync(dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(dev);
> +		pm_runtime_disable(dev);
> +		return ret;
> +	}
> +
> +	/* Get the sensor count in the VTM */
> +	val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
> +	cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
> +	cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
> +	bgp->ts_cnt = cnt;
> +
> +	data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
> +	if (!data) {
> +		ret = -ENOMEM;
> +		goto err_alloc;
> +	}
> +
> +	/* Workaround not needed if bit30/bit31 is set even for J721e */
> +	if (workaround_needed && (readl(bgp->fuse_base + 0x0) & 0xc0000000) == 0xc0000000) {
> +		dev_info(bgp->dev, "work around NOT needed!!\n");
> +		workaround_needed = 0;
> +	}
> +
> +	/* Register the thermal sensors */
> +	for (id = 0; id < cnt; id++) {
> +		data[id].sensor_id = id;
> +		data[id].bgp = bgp;
> +		data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
> +		data[id].stat_offset = data[id].ctrl_offset +
> +					K3_VTM_TMPSENS_STAT_OFFSET;
> +
> +		if (!workaround_needed)
> +			goto prepare_lookup;
> +		/* ref adc values for -40C, 30C & 125C respectively */
> +		data[id].ref_adc_val[0] = MINUS40CREF;
> +		data[id].ref_adc_val[1] = PLUS30CREF;
> +		data[id].ref_adc_val[2] = PLUS125CREF;
> +		get_efuse_values(id, &data[id], err, bgp);
> +
> +prepare_lookup:
> +		if (id == 0 && workaround_needed) {
> +			prep_lookup_table(err[0], err[1], err[2], 0);
> +		} else if (id == 0 && !workaround_needed) {
> +			for (j = 0; j < (sizeof(pvt_poly_golden) / 4); j++)
> +				derived_array[j] = pvt_poly_golden[j];
> +		}
> +
> +		val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
> +		val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
> +			K3_VTM_TMPSENS_CTRL_SOC |
> +			K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
> +		writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
> +
> +		bgp->ts_data[id] = &data[id];
> +		data[id].ti_thermal =
> +		devm_thermal_zone_of_sensor_register(bgp->dev, id,
> +						     &data[id],
> +						     &k3_of_thermal_ops);
> +		if (IS_ERR(data[id].ti_thermal)) {
> +			dev_err(bgp->dev, "thermal zone device is NULL\n");
> +			ret = PTR_ERR(data[id].ti_thermal);
> +			goto err_alloc;
> +		}
> +
> +		reg_cnt++;
> +
> +		/* Initialize Previous temp */
> +		k3_thermal_get_temp(&data[id], &data[id].prev_temp);
> +	}
> +
> +	/*
> +	 * Program TSHUT thresholds
> +	 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
> +	 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN  bit
> +	 *         This is already taken care as per of init
> +	 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN  bit
> +	 */
> +	high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
> +	low_max = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
> +
> +	writel((low_max << 16) | high_max, data[0].bgp->cfg2_base +
> +	       K3_VTM_MISC_CTRL2_OFFSET);
> +	mdelay(100);
> +	writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
> +	       K3_VTM_MISC_CTRL_OFFSET);
> +
> +	platform_set_drvdata(pdev, bgp);
> +
> +#ifdef DEBUG_VTM
> +	print_look_up_table(dev);
> +#endif
> +	return 0;
> +
> +err_alloc:
> +	pm_runtime_put_sync(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return ret;
> +}
> +
> +static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
> +{
> +	pm_runtime_put_sync(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j721e_data = {
> +	.workaround = 1,
> +};
> +
> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j7200_data = {
> +	.workaround = 0,
> +};
> +
> +static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
> +	{
> +		.compatible = "ti,j721e-vtm",
> +		.data = (void *)&k3_j72xx_bandgap_j721e_data,
> +	},
> +	{
> +		.compatible = "ti,j7200-vtm",
> +		.data = (void *)&k3_j72xx_bandgap_j7200_data,
> +	},
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
> +
> +static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
> +	.probe = k3_j72xx_bandgap_probe,
> +	.remove = k3_j72xx_bandgap_remove,
> +	.driver = {
> +		.name = "k3-j72xx-soc-thermal",
> +		.of_match_table	= of_k3_j72xx_bandgap_match,
> +	},
> +};
> +
> +module_platform_driver(k3_j72xx_bandgap_sensor_driver);
> +
> +MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("J Keerthy <[e-mail]>");
>

J, KEERTHY Oct. 19, 2021, 6:17 p.m. UTC | #2

On 10/19/2021 11:33 PM, Daniel Lezcano wrote:
> 
> Hi Keerthy,
> 
> 
> On 19/10/2021 18:06, Keerthy wrote:
>> Add VTM thermal support. In the Voltage Thermal Management
>> Module(VTM), K3 J72XX supplies a voltage reference and a temperature
>> sensor feature that are gathered in the band gap voltage and
>> temperature sensor (VBGAPTS) module. The band gap provides current and
>> voltage reference for its internal circuits and other analog IP
>> blocks. The analog-to-digital converter (ADC) produces an output value
>> that is proportional to the silicon temperature.
>>
>> Currently reading temperatures only is supported.  There are no
>> active/passive cooling agent supported.
>>
>> J721e SoCs have errata i2128: https://www.ti.com/lit/pdf/sprz455
>>
>> The VTM Temperature Monitors (TEMPSENSORs) are trimmed during production,
>> with the resulting values stored in software-readable registers. Software
>> should use these  register values when translating the Temperature
>> Monitor output codes to temperature values.
>>
>> It has an involved workaround. Software needs to read the error codes for
>> -40C, 30C, 125C from the efuse for each device & derive a new look up table
>> for adc to temperature conversion. Involved calculating slopes & constants
>> using 3 different straight line equations with adc refernce codes as the
>> y-axis & error codes in the x-axis.
>>
>> -40C to 30C
>> 30C to 125C
>> 125C to 150C
>>
>> With the above 2 line equations we derive the full look-up table to
>> workaround the errata i2128 for j721e SoC.
>>
>> Tested temperature reading on J721e SoC & J7200 SoC.
> 
> I take some the time to trace the values in the array below and it
> results in a very nice curve, almost flat.
> 
> That make me think the values are generated from a polynomial equation
> like the other driver.
> 
> So instead of adding a full blob of array here which are 8KB in total in
> this file, why not generate the array dynamically at probe time ?

Daniel,

First of all thanks for the quick feedback!

Warning: The below document is 200 odd MB document :-)

TRM: http://www.ti.com/lit/pdf/spruil1

Page: 2364

y = a4 × x4 + a3 × x3 + a2 × x2 + a1 × x + a0

Temperature = f(Code) °C

a4 = -9.2627E-12
a3 = 6.0373E-08
a2 = -1.7058E-04
a1 = 3.2512E-01
a0 = -4.9002E+01

I really do not want to implement that function in the driver. Hope you 
agree with me.

Similarly we have the other table having a different polynomial.

I used python to compute the tables from the equations.

Best Regards,
Keerthy

> 
> That will save space on disk and memory.
> 
> 
> 
>> Signed-off-by: Keerthy <[e-mail]>
>> ---
>>   drivers/thermal/Makefile           |   2 +-
>>   drivers/thermal/k3_j72xx_bandgap.c | 772 +++++++++++++++++++++++++++++
>>   2 files changed, 773 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/thermal/k3_j72xx_bandgap.c
>>
>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>> index 82fc3e616e54..6dcaf2028ddc 100644
>> --- a/drivers/thermal/Makefile
>> +++ b/drivers/thermal/Makefile
>> @@ -28,7 +28,7 @@ thermal_sys-$(CONFIG_CPU_IDLE_THERMAL)	+= cpuidle_cooling.o
>>   # devfreq cooling
>>   thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
>>   
>> -obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o
>> +obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o k3_j72xx_bandgap.o
>>   # platform thermal drivers
>>   obj-y				+= broadcom/
>>   obj-$(CONFIG_THERMAL_MMIO)		+= thermal_mmio.o
>> diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
>> new file mode 100644
>> index 000000000000..1aa048221291
>> --- /dev/null
>> +++ b/drivers/thermal/k3_j72xx_bandgap.c
>> @@ -0,0 +1,772 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * TI Bandgap temperature sensor driver for J72XX SoC Family
>> + *
>> + * Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com/
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/err.h>
>> +#include <linux/types.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/io.h>
>> +#include <linux/thermal.h>
>> +#include <linux/of.h>
>> +#include <linux/delay.h>
>> +
>> +#define K3_VTM_DEVINFO_PWR0_OFFSET		0x4
>> +#define K3_VTM_DEVINFO_PWR0_CVD_CT_MASK		0xf
>> +#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK	0xf0
>> +#define K3_VTM_TMPSENS0_CTRL_OFFSET		0x300
>> +#define K3_VTM_MISC_CTRL_OFFSET			0xc
>> +#define K3_VTM_TMPSENS_STAT_OFFSET		0x8
>> +#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN		0x1
>> +#define K3_VTM_MISC_CTRL2_OFFSET		0x10
>> +#define K3_VTM_REGS_PER_TS			0x10
>> +#define K3_VTM_TS_STAT_DTEMP_MASK		0x3ff
>> +#define K3_VTM_MAX_NUM_TS			8
>> +#define K3_VTM_TMPSENS_CTRL_CBIASSEL		BIT(0)
>> +#define K3_VTM_TMPSENS_CTRL_SOC			BIT(5)
>> +#define K3_VTM_TMPSENS_CTRL_CLRZ		BIT(6)
>> +#define K3_VTM_TMPSENS_CTRL_CLKON_REQ		BIT(7)
>> +#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN	BIT(11)
>> +
>> +#define K3_VTM_CORRECTION_TEMP_CNT		3
>> +
>> +#define K3_VTM_ADC_BEGIN_VAL			6
>> +#define K3_VTM_ADC_END_VAL			944
>> +
>> +#define MINUS40CREF				5
>> +#define PLUS30CREF				253
>> +#define PLUS125CREF				730
>> +#define PLUS150CREF				940
>> +
>> +#define MAX_TEMP				123000
>> +#define COOL_DOWN_TEMP				105000
>> +
>> +//#define DEBUG_VTM
>> +
>> +static int derived_array[1024];
>> +
>> +/* Reference Look up table when work around is NOT needed */
>> +static const int pvt_poly_golden[] = {
>> +	-49002, -48677, -48352, -48028, -47704, -47381, -47057, -46734, -46412,
>> +	-46090, -45768, -45446, -45125, -44804, -44484, -44163, -43844, -43524,
>> +	-43205, -42886, -42567, -42249, -41931, -41614, -41297, -40980, -40663,
>> +	-40347, -40031, -39716, -39400, -39085, -38771, -38457, -38143, -37829,
>> +	-37516, -37203, -36890, -36578, -36266, -35955, -35643, -35332, -35022,
>> +	-34712, -34402, -34092, -33783, -33474, -33165, -32857, -32549, -32241,
>> +	-31934, -31626, -31320, -31013, -30707, -30401, -30096, -29791, -29486,
>> +	-29182, -28877, -28573, -28270, -27967, -27664, -27361, -27059, -26757,
>> +	-26455, -26154, -25853, -25552, -25252, -24952, -24652, -24353, -24054,
>> +	-23755, -23456, -23158, -22860, -22563, -22265, -21968, -21672, -21376,
>> +	-21079, -20784, -20488, -20193, -19899, -19604, -19310, -19016, -18723,
>> +	-18429, -18136, -17844, -17551, -17259, -16968, -16676, -16385, -16094,
>> +	-15804, -15514, -15224, -14934, -14645, -14356, -14067, -13779, -13491,
>> +	-13203, -12916, -12628, -12342, -12055, -11769, -11483, -11197, -10912,
>> +	-10627, -10342, -10057, -9773, -9489, -9206, -8922, -8639, -8357, -8074,
>> +	-7792, -7510, -7229, -6947, -6666, -6386, -6105, -5825, -5546, -5266,
>> +	-4987, -4708, -4429, -4151, -3873, -3595, -3318, -3041, -2764, -2487,
>> +	-2211, -1935, -1659, -1384, -1108, -834, -559, -285, -11, 263, 537, 810,
>> +	1083, 1355, 1628, 1900, 2171, 2443, 2714, 2985, 3255, 3526, 3796, 4066,
>> +	4335, 4604, 4873, 5142, 5410, 5679, 5946, 6214, 6481, 6748, 7015, 7281,
>> +	7548, 7813, 8079, 8344, 8609, 8874, 9139, 9403, 9667, 9931, 10194,
>> +	10457, 10720, 10983, 11245, 11507, 11769, 12030, 12292, 12553, 12813,
>> +	13074, 13334, 13594, 13854, 14113, 14372, 14631, 14889, 15148, 15406,
>> +	15664, 15921, 16178, 16435, 16692, 16948, 17205, 17461, 17716, 17972,
>> +	18227, 18482, 18736, 18991, 19245, 19498, 19752, 20005, 20258, 20511,
>> +	20764, 21016, 21268, 21520, 21771, 22022, 22273, 22524, 22774, 23025,
>> +	23274, 23524, 23774, 24023, 24272, 24520, 24769, 25017, 25265, 25512,
>> +	25760, 26007, 26254, 26500, 26747, 26993, 27239, 27484, 27730, 27975,
>> +	28220, 28464, 28708, 28953, 29196, 29440, 29683, 29927, 30169, 30412,
>> +	30654, 30896, 31138, 31380, 31621, 31862, 32103, 32344, 32584, 32824,
>> +	33064, 33304, 33543, 33783, 34022, 34260, 34499, 34737, 34975, 35213,
>> +	35450, 35687, 35924, 36161, 36397, 36634, 36870, 37105, 37341, 37576,
>> +	37811, 38046, 38281, 38515, 38749, 38983, 39217, 39450, 39683, 39916,
>> +	40149, 40381, 40614, 40846, 41077, 41309, 41540, 41771, 42002, 42233,
>> +	42463, 42693, 42923, 43153, 43382, 43611, 43840, 44069, 44297, 44526,
>> +	44754, 44981, 45209, 45436, 45663, 45890, 46117, 46343, 46570, 46796,
>> +	47021, 47247, 47472, 47697, 47922, 48147, 48371, 48595, 48819, 49043,
>> +	49266, 49490, 49713, 49935, 50158, 50380, 50603, 50824, 51046, 51268,
>> +	51489, 51710, 51931, 52151, 52372, 52592, 52812, 53031, 53251, 53470,
>> +	53689, 53908, 54127, 54345, 54563, 54781, 54999, 55217, 55434, 55651,
>> +	55868, 56085, 56301, 56517, 56733, 56949, 57165, 57380, 57595, 57810,
>> +	58025, 58239, 58454, 58668, 58882, 59095, 59309, 59522, 59735, 59948,
>> +	60160, 60373, 60585, 60797, 61009, 61220, 61432, 61643, 61854, 62064,
>> +	62275, 62485, 62695, 62905, 63115, 63324, 63534, 63743, 63952, 64160,
>> +	64369, 64577, 64785, 64993, 65200, 65408, 65615, 65822, 66029, 66236,
>> +	66442, 66648, 66854, 67060, 67266, 67471, 67676, 67881, 68086, 68291,
>> +	68495, 68699, 68903, 69107, 69311, 69514, 69717, 69920, 70123, 70326,
>> +	70528, 70730, 70932, 71134, 71336, 71537, 71738, 71939, 72140, 72341,
>> +	72541, 72742, 72942, 73142, 73341, 73541, 73740, 73939, 74138, 74337,
>> +	74535, 74733, 74932, 75130, 75327, 75525, 75722, 75919, 76116, 76313,
>> +	76510, 76706, 76902, 77098, 77294, 77490, 77685, 77881, 78076, 78271,
>> +	78465, 78660, 78854, 79048, 79242, 79436, 79630, 79823, 80016, 80210,
>> +	80402, 80595, 80788, 80980, 81172, 81364, 81556, 81747, 81939, 82130,
>> +	82321, 82512, 82702, 82893, 83083, 83273, 83463, 83653, 83843, 84032,
>> +	84221, 84410, 84599, 84788, 84976, 85165, 85353, 85541, 85728, 85916,
>> +	86103, 86291, 86478, 86665, 86851, 87038, 87224, 87411, 87597, 87782,
>> +	87968, 88154, 88339, 88524, 88709, 88894, 89078, 89263, 89447, 89631,
>> +	89815, 89999, 90182, 90366, 90549, 90732, 90915, 91098, 91280, 91463,
>> +	91645, 91827, 92009, 92191, 92372, 92554, 92735, 92916, 93097, 93277,
>> +	93458, 93638, 93818, 93998, 94178, 94358, 94537, 94717, 94896, 95075,
>> +	95254, 95433, 95611, 95790, 95968, 96146, 96324, 96501, 96679, 96856,
>> +	97033, 97211, 97387, 97564, 97741, 97917, 98093, 98269, 98445, 98621,
>> +	98797, 98972, 99147, 99322, 99497, 99672, 99847, 100021, 100196, 100370,
>> +	100544, 100718, 100891, 101065, 101238, 101411, 101584, 101757, 101930,
>> +	102103, 102275, 102447, 102619, 102791, 102963, 103135, 103306, 103478,
>> +	103649, 103820, 103991, 104161, 104332, 104502, 104673, 104843, 105013,
>> +	105182, 105352, 105522, 105691, 105860, 106029, 106198, 106367, 106535,
>> +	106704, 106872, 107040, 107208, 107376, 107544, 107711, 107878, 108046,
>> +	108213, 108380, 108546, 108713, 108880, 109046, 109212, 109378, 109544,
>> +	109710, 109875, 110041, 110206, 110371, 110536, 110701, 110866, 111030,
>> +	111195, 111359, 111523, 111687, 111851, 112015, 112178, 112342, 112505,
>> +	112668, 112831, 112994, 113157, 113319, 113482, 113644, 113806, 113968,
>> +	114130, 114292, 114453, 114615, 114776, 114937, 115098, 115259, 115420,
>> +	115580, 115741, 115901, 116061, 116221, 116381, 116541, 116701, 116860,
>> +	117019, 117179, 117338, 117497, 117655, 117814, 117973, 118131, 118289,
>> +	118447, 118605, 118763, 118921, 119078, 119236, 119393, 119550, 119707,
>> +	119864, 120021, 120178, 120334, 120490, 120647, 120803, 120959, 121115,
>> +	121270, 121426, 121581, 121737, 121892, 122047, 122202, 122356, 122511,
>> +	122666, 122820, 122974, 123128, 123282, 123436, 123590, 123744, 123897,
>> +	124050, 124204, 124357, 124510, 124662, 124815, 124968, 125120, 125273,
>> +	125425, 125577, 125729, 125881, 126032, 126184, 126335, 126487, 126638,
>> +	126789, 126940, 127091, 127241, 127392, 127542, 127693, 127843, 127993,
>> +	128143, 128293, 128442, 128592, 128741, 128891, 129040, 129189, 129338,
>> +	129487, 129635, 129784, 129932, 130081, 130229, 130377, 130525, 130673,
>> +	130821, 130968, 131116, 131263, 131410, 131558, 131705, 131851, 131998,
>> +	132145, 132291, 132438, 132584, 132730, 132876, 133022, 133168, 133314,
>> +	133460, 133605, 133750, 133896, 134041, 134186, 134331, 134476, 134620,
>> +	134765, 134909, 135054, 135198, 135342, 135486, 135630, 135773, 135917,
>> +	136061, 136204, 136347, 136491, 136634, 136777, 136919, 137062, 137205,
>> +	137347, 137490, 137632, 137774, 137916, 138058, 138200, 138342, 138483,
>> +	138625, 138766, 138907, 139049, 139190, 139331, 139471, 139612, 139753,
>> +	139893, 140034, 140174, 140314, 140454, 140594, 140734, 140874, 141013,
>> +	141153, 141292, 141432, 141571, 141710, 141849, 141988, 142127, 142265,
>> +	142404, 142542, 142681, 142819, 142957, 143095, 143233, 143371, 143509,
>> +	143646, 143784, 143921, 144058, 144196, 144333, 144470, 144607, 144743,
>> +	144880, 145017, 145153, 145289, 145426, 145562, 145698, 145834, 145970,
>> +	146105, 146241, 146377, 146512, 146647, 146783, 146918, 147053, 147188,
>> +	147323, 147457, 147592, 147727, 147861, 147995, 148130, 148264, 148398,
>> +	148532, 148666, 148799, 148933, 149067, 149200, 149333, 149467, 149600,
>> +	149733, 149866, 149999, 150131, 150264, 150397, 150529, 150661, 150794,
>> +	150926, 151058, 151190, 151322, 151454, 151585, 151717, 151848, 151980,
>> +	152111,	152242, 152373, 152505, 152635, 152766, 152897, 153028, 153158,
>> +	153289, 153419, 153549, 153680, 153810, 153940, 154070, 154199, 154329,
>> +	154459, 154588, 154718, 154847, 154976, 155105, 155235, 155363, 155492,
>> +	155621, 155750, 155879, 156007, 156135, 156264, 156392, 156520, 156648,
>> +	156776, 156904, 157032, 157160, 157287, 157415, 157542, 157670, 157797,
>> +	157924, 158051, 158178, 158305, 158432, 158559, 158685, 158812, 158938,
>> +	159065, 159191, 159317, 159443, 159569,
>> +};
>> +
>> +/* Reference Look up table when work around is needed */
>> +static const int pvt_poly[] = {
>> +	-41523, -41210, -40898, -40586, -40274, -39963, -39651, -39340,	-39029,
>> +	-38718, -38408, -38098, -37788, -37478, -37168, -36859, -36550, -36241,
>> +	-35933, -35624, -35316, -35008, -34701, -34393, -34086, -33779, -33472,
>> +	-33166, -32859, -32553, -32247, -31942, -31636, -31331, -31026, -30722,
>> +	-30417, -30113, -29809, -29505, -29202, -28899, -28596, -28293, -27990,
>> +	-27688, -27386, -27084, -26782, -26481, -26179, -25878, -25578, -25277,
>> +	-24977, -24677, -24377, -24078, -23778, -23479, -23180, -22882, -22583,
>> +	-22285, -21987, -21689, -21392, -21095, -20797, -20501, -20204, -19908,
>> +	-19612, -19316, -19020, -18725, -18430, -18135, -17840, -17545, -17251,
>> +	-16957, -16663, -16370, -16077, -15783, -15491, -15198,	-14906, -14613,
>> +	-14321, -14030, -13738, -13447, -13156, -12865, -12575, -12284, -11994,
>> +	-11704, -11415, -11125, -10836, -10547, -10259, -9970, -9682, -9394,
>> +	-9106, -8819, -8531, -8244, -7957, -7671, -7384, -7098, -6812, -6527,
>> +	-6241, -5956, -5671, -5386, -5102, -4817, -4533, -4250, -3966, -3683,
>> +	-3399, -3117, -2834, -2551, -2269, -1987, -1706, -1424, -1143, -862,
>> +	-581, -300, -20, 260, 540, 820, 1099, 1378, 1657, 1936, 2215, 2493,
>> +	2771, 3049, 3326, 3604, 3881, 4158, 4434, 4711, 4987, 5263, 5539, 5814,
>> +	6089, 6364, 6639, 6914, 7188, 7462, 7736, 8010, 8283, 8556, 8829, 9102,
>> +	9374, 9647, 9919, 10191, 10462, 10733, 11005, 11275, 11546, 11816,
>> +	12087, 12357, 12626, 12896, 13165, 13434, 13703, 13971, 14240, 14508,
>> +	14776, 15043, 15311, 15578, 15845, 16111, 16378, 16644, 16910, 17176,
>> +	17441, 17707, 17972, 18237, 18501, 18766, 19030, 19294, 19557, 19821,
>> +	20084, 20347, 20610, 20872, 21135, 21397, 21658, 21920, 22181, 22443,
>> +	22703, 22964, 23225, 23485, 23745, 24005, 24264, 24523, 24782, 25041,
>> +	25300, 25558, 25816, 26074, 26332, 26589, 26846, 27103, 27360, 27617,
>> +	27873, 28129, 28385, 28640, 28896, 29151, 29406, 29660, 29915, 30169,
>> +	30423, 30677, 30930, 31183, 31437, 31689, 31942, 32194, 32446, 32698,
>> +	32950, 33201, 33452, 33703, 33954, 34205, 34455, 34705, 34955, 35204,
>> +	35454, 35703, 35952, 36200, 36449, 36697, 36945, 37192, 37440, 37687,
>> +	37934, 38181, 38427, 38674, 38920, 39166, 39411, 39657, 39902, 40147,
>> +	40391, 40636, 40880, 41124, 41368, 41611, 41855, 42098, 42341, 42583,
>> +	42826, 43068, 43310, 43551, 43793, 44034, 44275, 44516, 44756, 44997,
>> +	45237, 45477, 45716, 45956, 46195, 46434, 46672, 46911, 47149, 47387,
>> +	47625, 47862, 48100, 48337, 48573, 48810, 49046, 49282, 49518, 49754,
>> +	49989, 50225, 50460, 50694, 50929, 51163, 51397, 51631, 51865, 52098,
>> +	52331, 52564, 52797, 53029, 53261, 53493, 53725, 53956, 54188, 54419,
>> +	54650, 54880, 55110, 55341, 55570, 55800, 56030, 56259, 56488, 56716,
>> +	56945, 57173, 57401, 57629, 57856, 58084, 58311, 58538, 58764, 58991,
>> +	59217, 59443, 59669, 59894, 60119, 60344, 60569, 60794, 61018, 61242,
>> +	61466, 61690, 61913, 62136, 62359, 62582, 62804, 63026, 63249, 63470,
>> +	63692, 63913, 64134, 64355, 64576, 64796, 65016, 65236, 65456, 65675,
>> +	65894, 66113, 66332, 66551, 66769, 66987, 67205, 67423, 67640, 67857,
>> +	68074, 68291, 68507, 68723, 68939, 69155, 69371, 69586, 69801, 70016,
>> +	70230, 70445, 70659, 70873, 71086, 71300, 71513, 71726, 71939, 72151,
>> +	72364, 72576, 72787, 72999, 73210, 73422, 73632, 73843, 74053, 74264,
>> +	74474, 74683, 74893, 75102, 75311, 75520, 75729, 75937, 76145, 76353,
>> +	76561, 76768, 76975, 77182, 77389, 77595, 77802, 78008, 78213, 78419,
>> +	78624, 78829, 79034, 79239, 79443, 79647, 79851, 80055, 80259, 80462,
>> +	80665, 80868, 81070, 81273, 81475, 81676, 81878, 82079, 82281, 82482,
>> +	82682, 82883, 83083, 83283, 83483, 83682, 83882, 84081, 84280, 84478,
>> +	84677, 84875, 85073, 85270, 85468, 85665, 85862, 86059, 86255, 86452,
>> +	86648, 86844, 87039, 87234, 87430, 87625, 87819, 88014, 88208, 88402,
>> +	88596, 88789, 88982, 89175, 89368, 89561, 89753, 89945, 90137, 90329,
>> +	90520, 90712, 90903, 91093, 91284, 91474, 91664, 91854, 92044, 92233,
>> +	92422, 92611, 92800, 92988, 93176, 93364, 93552, 93739, 93927, 94114,
>> +	94301, 94487, 94673, 94860, 95045, 95231, 95417, 95602, 95787, 95971,
>> +	96156, 96340, 96524, 96708, 96892, 97075, 97258, 97441, 97624, 97806,
>> +	97988, 98170, 98352, 98533, 98714, 98895, 99076, 99257, 99437, 99617,
>> +	99797, 99977, 100156, 100335, 100514, 100693, 100871, 101050, 101228,
>> +	101405, 101583, 101760, 101937, 102114, 102291, 102467, 102643, 102819,
>> +	102995, 103170, 103346, 103521, 103695, 103870, 104044, 104218, 104392,
>> +	104566, 104739, 104912, 105085, 105258, 105430, 105603, 105775, 105946,
>> +	106118, 106289, 106460, 106631, 106802, 106972, 107142, 107312, 107482,
>> +	107651, 107820, 107989, 108158, 108327, 108495, 108663, 108831, 108998,
>> +	109166, 109333, 109500, 109666, 109833, 109999, 110165, 110331, 110496,
>> +	110661, 110827, 110991, 111156, 111320, 111484, 111648, 111812, 111975,
>> +	112139, 112301, 112464, 112627, 112789, 112951, 113113, 113274, 113436,
>> +	113597, 113758, 113918, 114079, 114239, 114399, 114559, 114718, 114877,
>> +	115036, 115195, 115354, 115512, 115670, 115828, 115986, 116143, 116300,
>> +	116457, 116614, 116770, 116926, 117082, 117238, 117394, 117549, 117704,
>> +	117859, 118014, 118168, 118322, 118476, 118630, 118783, 118937, 119090,
>> +	119242, 119395, 119547, 119699, 119851, 120003, 120154, 120305, 120456,
>> +	120607, 120757, 120907, 121057, 121207, 121357, 121506, 121655, 121804,
>> +	121953, 122101, 122249, 122397, 122545, 122692, 122839, 122986, 123133,
>> +	123280, 123426, 123572, 123718, 123863, 124009, 124154, 124299, 124443,
>> +	124588, 124732, 124876, 125020, 125163, 125306, 125449, 125592, 125735,
>> +	125877, 126019, 126161, 126303, 126444, 126585, 126726, 126867, 127008,
>> +	127148, 127288, 127428, 127567, 127707, 127846, 127985, 128123, 128262,
>> +	128400, 128538, 128676, 128813, 128950, 129087, 129224, 129361, 129497,
>> +	129633, 129769, 129905, 130040, 130175, 130310, 130445, 130579, 130713,
>> +	130847, 130981, 131115, 131248, 131381, 131514, 131647, 131779, 131911,
>> +	132043, 132175, 132306, 132438, 132569, 132699, 132830, 132960, 133090,
>> +	133220, 133350, 133479, 133608, 133737, 133866, 133994, 134123, 134251,
>> +	134378, 134506, 134633, 134760, 134887, 135014, 135140, 135266, 135392,
>> +	135518, 135643, 135768, 135893, 136018, 136143, 136267, 136391, 136515,
>> +	136638, 136762, 136885, 137008, 137130, 137253, 137375, 137497, 137619,
>> +	137740, 137862, 137983, 138103, 138224, 138344, 138464, 138584, 138704,
>> +	138823, 138943, 139062, 139180, 139299, 139417, 139535, 139653, 139770,
>> +	139888, 140005, 140122, 140238, 140355, 140471, 140587, 140703, 140818,
>> +	140933, 141048, 141163, 141278, 141392, 141506, 141620, 141734, 141847,
>> +	141960, 142073, 142186, 142298, 142411, 142523, 142634, 142746, 142857,
>> +	142968, 143079, 143190, 143300, 143410, 143520, 143630, 143740, 143849,
>> +	143958, 144067, 144175, 144283, 144391, 144499, 144607, 144714, 144821,
>> +	144928, 145035, 145142, 145248, 145354, 145459, 145565, 145670, 145775,
>> +	145880, 145985, 146089, 146193, 146297, 146401, 146504, 146608, 146711,
>> +	146813, 146916, 147018, 147120, 147222, 147324, 147425, 147526, 147627,
>> +	147728, 147828, 147928, 148028, 148128, 148228, 148327, 148426, 148525,
>> +	148623, 148722, 148820, 148918, 149015, 149113, 149210, 149307, 149404,
>> +	149500, 149596, 149692, 149788, 149884, 149979, 150074, 150169, 150264,
>> +	150358, 150452, 150546, 150640, 150733, 150827, 150920, 151013, 151105,
>> +	151197, 151290, 151381, 151473, 151564, 151656, 151747, 151837, 151928,
>> +	152018, 152108, 152198, 152287, 152377, 152466, 152555, 152643, 152732,
>> +	152820, 152908, 152995, 153083, 153170, 153257, 153344, 153430, 153517,
>> +	153603, 153689, 153774, 153860, 153945, 154030, 154114, 154199, 154283,
>> +	154367, 154451, 154534, 154618, 154701, 154784, 154866, 154949, 155031,
>> +	155113, 155194, 155276, 155357, 155438, 155519, 155599, 155680, 155760,
>> +	155839, 155919, 155998, 156078, 156156, 156235, 156314, 156392, 156470,
>> +	156547, 156625, 156702, 156779, 156856, 156933, 157009, 157085, 157161,
>> +};
>> +
>> +static void fill_table(int err1, int err2, int ref1, int ref2, int idx1,
>> +		       int idx2)
>> +{
>> +	int m, c, num, den, i, err;
>> +
>> +	/**
>> +	 * Calculate the slope with adc values read from the register
>> +	 * as the y-axis param and err in adc value as x-axis param
>> +	 */
>> +	if (err1 != err2) {
>> +		num = ref2 - ref1;
>> +		den = err2 - err1;
>> +		m = num / den;
>> +		c = ref2 - m * err2;
>> +		for (i = idx1; i <= idx2; i++) {
>> +			err = (i - c) / m;
>> +			if (((i + err1) < 0) || ((i + err1) > 1023))
>> +				continue;
>> +			derived_array[i] = pvt_poly[i + err];
>> +		}
>> +	} else { /* Constant error take care of divide by zero */
>> +		for (i = idx1; i < idx2; i++) {
>> +			if (((i + err1) < 0) || ((i + err1) > 1023))
>> +				continue;
>> +			derived_array[i] = pvt_poly[i + err1];
>> +		}
>> +	}
>> +}
>> +
>> +static int prep_lookup_table(int minus40cerr, int plus30cerr, int plus125cerr,
>> +			     int plus150cerr)
>> +{
>> +	int start_temp, inc, i;
>> +
>> +	/* Fill up the lookup table region -40C to +30C */
>> +	fill_table(minus40cerr, plus30cerr, MINUS40CREF, PLUS30CREF, 0,
>> +		   PLUS30CREF);
>> +	/* Fill up the lookup table region +30C to +125C */
>> +	fill_table(plus30cerr, plus125cerr, PLUS30CREF, PLUS125CREF, PLUS30CREF,
>> +		   PLUS125CREF);
>> +	/* Fill up the lookup table region +125C to +150C */
>> +	fill_table(plus125cerr, plus150cerr, PLUS125CREF, PLUS150CREF, PLUS125CREF,
>> +		   PLUS150CREF);
>> +
>> +	/* Get to the first valid temperature */
>> +	i = 0;
>> +	while (!derived_array[i])
>> +		i++;
>> +
>> +	start_temp = i;
>> +	/*
>> +	 * Get to the last zero index and back fill the temperature for
>> +	 * sake of continuity
>> +	 */
>> +	if (i) {
>> +		/* 300 milli celsius steps */
>> +		while (i--)
>> +			derived_array[i] = derived_array[i + 1] - 300;
>> +		/* case 0 */
>> +		derived_array[i] = derived_array[i + 1] - 300;
>> +	}
>> +
>> +	/*
>> +	 * Fill the last trailing 0s which are unfilled with increments of
>> +	 * 100 milli celsius till 1023 code
>> +	 */
>> +	i = 1023;
>> +	while (!derived_array[i])
>> +		i--;
>> +
>> +	i++;
>> +	inc = 1;
>> +	while (i < 1024) {
>> +		derived_array[i] = derived_array[i - 1] + inc * 100;
>> +		i++;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +struct k3_thermal_data;
>> +
>> +struct k3_j72xx_bandgap {
>> +	struct device *dev;
>> +	void __iomem *base;
>> +	void __iomem *cfg2_base;
>> +	void __iomem *fuse_base;
>> +	const struct k3_j72xx_bandgap_data	*conf;
>> +	spinlock_t lock; /* shields this struct */
>> +	int ts_cnt;
>> +	struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
>> +};
>> +
>> +/* common data structures */
>> +struct k3_thermal_data {
>> +	struct thermal_zone_device *ti_thermal;
>> +	struct thermal_cooling_device *cool_dev;
>> +	struct k3_j72xx_bandgap *bgp;
>> +	enum thermal_device_mode mode;
>> +	int sensor_id;
>> +	u32 ctrl_offset;
>> +	u32 stat_offset;
>> +	int prev_temp;
>> +	int ct_offsets[K3_VTM_CORRECTION_TEMP_CNT];
>> +	int ct_bm[K3_VTM_CORRECTION_TEMP_CNT];
>> +	int ref_adc_val[3];
>> +	int act_adc_val[3];
>> +	int slope[2];
>> +	int coeff[2];
>> +};
>> +
>> +int two_cmp(int tmp, int mask)
>> +{
>> +	tmp = ~(tmp);
>> +	tmp &= mask;
>> +	tmp += 1;
>> +
>> +	/* Return negative value */
>> +	return (0 - tmp);
>> +}
>> +
>> +static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
>> +				       unsigned int s2)
>> +{
>> +	int d01 = abs(s0 - s1);
>> +	int d02 = abs(s0 - s2);
>> +	int d12 = abs(s1 - s2);
>> +
>> +	if (d01 <= d02 && d01 <= d12)
>> +		return (s0 + s1) / 2;
>> +
>> +	if (d02 <= d01 && d02 <= d12)
>> +		return (s0 + s2) / 2;
>> +
>> +	return (s1 + s2) / 2;
>> +}
>> +
>> +static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
>> +				   int *temp)
>> +{
>> +	struct k3_j72xx_bandgap *bgp;
>> +	unsigned int dtemp, s0, s1, s2;
>> +
>> +	bgp = devdata->bgp;
>> +	/*
>> +	 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There
>> +	 * is a variation of the order for certain degree centigrade on AM654.
>> +	 * Work around that by getting the average of two closest
>> +	 * readings out of three readings everytime we want to
>> +	 * report temperatures.
>> +	 *
>> +	 * Errata workaround.
>> +	 */
>> +	s0 = readl(bgp->base + devdata->stat_offset) &
>> +		K3_VTM_TS_STAT_DTEMP_MASK;
>> +	s1 = readl(bgp->base + devdata->stat_offset) &
>> +		K3_VTM_TS_STAT_DTEMP_MASK;
>> +	s2 = readl(bgp->base + devdata->stat_offset) &
>> +		K3_VTM_TS_STAT_DTEMP_MASK;
>> +	dtemp = vtm_get_best_value(s0, s1, s2);
>> +
>> +	if (dtemp < 0 || dtemp > 1023)
>> +		return -EINVAL;
>> +
>> +	*temp = derived_array[dtemp];
>> +
>> +	return 0;
>> +}
>> +
>> +/* Get temperature callback function for thermal zone */
>> +static int k3_thermal_get_temp(void *devdata, int *temp)
>> +{
>> +	struct k3_thermal_data *data = devdata;
>> +	int ret = 0;
>> +
>> +	ret = k3_bgp_read_temp(data, temp);
>> +	if (ret)
>> +		return ret;
>> +
>> +	data->prev_temp = *temp;
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct thermal_zone_of_device_ops k3_of_thermal_ops = {
>> +	.get_temp = k3_thermal_get_temp,
>> +};
>> +
>> +static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
>> +{
>> +	int low = 0, high = 1023, mid;
>> +
>> +	if (temp > 160000 || temp < -50000)
>> +		return -EINVAL;
>> +
>> +	/* Binary search to find the adc code */
>> +	while (low < (high - 1)) {
>> +		mid = (low + high) / 2;
>> +		if (temp <= derived_array[mid])
>> +			high = mid;
>> +		else
>> +			low = mid;
>> +	}
>> +
>> +	return mid;
>> +}
>> +
>> +static void get_efuse_values(int id, struct k3_thermal_data *data, int *err,
>> +			     struct k3_j72xx_bandgap *bgp)
>> +{
>> +	int i, tmp, pow;
>> +
>> +	/* Populate efuse reg offsets & Bit masks for -40C, 30C, 125C */
>> +	switch (id) {
>> +	case 0:
>> +		data->ct_offsets[0] = 0x0;
>> +		data->ct_offsets[1] = 0x8;
>> +		data->ct_offsets[2] = 0x4;
>> +		data->ct_bm[0] = 0x3f;
>> +		data->ct_bm[1] = 0x1fe000;
>> +		data->ct_bm[2] = 0x1ff;
>> +		break;
>> +
>> +	case 1:
>> +		data->ct_offsets[0] = 0x0;
>> +		data->ct_offsets[1] = 0x8;
>> +		data->ct_offsets[2] = 0x4;
>> +		data->ct_bm[0] = 0xfc0;
>> +		data->ct_bm[1] = 0x1fe00000;
>> +		data->ct_bm[2] = 0x3fe00;
>> +		break;
>> +
>> +	case 2:
>> +		data->ct_offsets[0] = 0x0;
>> +		data->ct_offsets[1] = -1;
>> +		data->ct_offsets[2] = 0x4;
>> +		data->ct_bm[0] = 0x3f000;
>> +		data->ct_bm[1] = 0x7f800000;
>> +		data->ct_bm[2] = 0x7fc0000;
>> +		break;
>> +
>> +	case 3:
>> +		data->ct_offsets[0] = 0x0;
>> +		data->ct_offsets[1] = 0xC;
>> +		data->ct_offsets[2] = -1; /* Spread across 2 registers */
>> +		data->ct_bm[0] = 0xfc0000;
>> +		data->ct_bm[1] = 0x1fe0;
>> +		data->ct_bm[2] = 0x1f800000;
>> +		break;
>> +
>> +	case 4:
>> +		data->ct_offsets[0] = 0x0;
>> +		data->ct_offsets[1] = 0xc;
>> +		data->ct_offsets[2] = 0x8;
>> +		data->ct_bm[0] = 0x3f000000;
>> +		data->ct_bm[1] = 0x1fe000;
>> +		data->ct_bm[2] = 0x1ff0;
>> +		break;
>> +	}
>> +
>> +	for (i = 0; i < 3; i++) {
>> +		/* Extract the offset value using bit-mask */
>> +		if (data->ct_offsets[i] == -1 && i == 1) {
>> +			/* 25C offset Case of Sensor 2 split between 2 regs */
>> +			tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29);
>> +			tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3);
>> +			pow = tmp & 0x80;
>> +		} else if (data->ct_offsets[i] == -1 && i == 2) {
>> +			/* 125C Case of Sensor 3 split between 2 regs */
>> +			tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27);
>> +			tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5);
>> +			pow = tmp & 0x100;
>> +		} else {
>> +			tmp = readl(bgp->fuse_base + data->ct_offsets[i]);
>> +			tmp &= data->ct_bm[i];
>> +			tmp = tmp >> __ffs(data->ct_bm[i]);
>> +
>> +			/* Obtain the sign bit pow*/
>> +			pow = data->ct_bm[i] >> __ffs(data->ct_bm[i]);
>> +			pow += 1;
>> +			pow /= 2;
>> +		}
>> +
>> +		/* Check for negative value */
>> +		if (tmp & pow) {
>> +			/* 2's complement value */
>> +			tmp = two_cmp(tmp, data->ct_bm[i] >> __ffs(data->ct_bm[i]));
>> +		}
>> +		err[i] = tmp;
>> +	}
>> +}
>> +
>> +#ifdef DEBUG_VTM
>> +static void print_look_up_table(struct device *dev)
>> +{
>> +	int i;
>> +
>> +	dev_info(dev, "The contents of derived array\n");
>> +	dev_info(dev, "Code   Temperaturei\n");
>> +	for (i = 0; i <= 1023; i++)
>> +		dev_info(dev, "%d       %d\n", i, derived_array[i]);
>> +}
>> +#endif
>> +
>> +static const struct of_device_id of_k3_j72xx_bandgap_match[];
>> +
>> +struct k3_j72xx_bandgap_j72xx_data {
>> +	unsigned int	workaround;
>> +};
>> +
>> +static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
>> +{
>> +	int ret = 0, cnt, val, id, reg_cnt = 0, j;
>> +	int err[3], high_max, low_max;
>> +	struct resource *res;
>> +	struct device *dev = &pdev->dev;
>> +	struct k3_j72xx_bandgap *bgp;
>> +	struct k3_thermal_data *data;
>> +	int workaround_needed = 0;
>> +	const struct of_device_id *of_id;
>> +	const struct k3_j72xx_bandgap_j72xx_data *driver_data;
>> +
>> +	bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
>> +	if (!bgp)
>> +		return -ENOMEM;
>> +
>> +	bgp->dev = dev;
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	bgp->base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(bgp->base))
>> +		return PTR_ERR(bgp->base);
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>> +	bgp->cfg2_base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(bgp->cfg2_base))
>> +		return PTR_ERR(bgp->cfg2_base);
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>> +	bgp->fuse_base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(bgp->fuse_base))
>> +		return PTR_ERR(bgp->fuse_base);
>> +
>> +	of_id = of_match_device(of_k3_j72xx_bandgap_match, &pdev->dev);
>> +	if (of_id) {
>> +		driver_data = of_id->data;
>> +		workaround_needed = driver_data->workaround;
>> +	}
>> +
>> +	pm_runtime_enable(dev);
>> +	ret = pm_runtime_get_sync(dev);
>> +	if (ret < 0) {
>> +		pm_runtime_put_noidle(dev);
>> +		pm_runtime_disable(dev);
>> +		return ret;
>> +	}
>> +
>> +	/* Get the sensor count in the VTM */
>> +	val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
>> +	cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
>> +	cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
>> +	bgp->ts_cnt = cnt;
>> +
>> +	data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
>> +	if (!data) {
>> +		ret = -ENOMEM;
>> +		goto err_alloc;
>> +	}
>> +
>> +	/* Workaround not needed if bit30/bit31 is set even for J721e */
>> +	if (workaround_needed && (readl(bgp->fuse_base + 0x0) & 0xc0000000) == 0xc0000000) {
>> +		dev_info(bgp->dev, "work around NOT needed!!\n");
>> +		workaround_needed = 0;
>> +	}
>> +
>> +	/* Register the thermal sensors */
>> +	for (id = 0; id < cnt; id++) {
>> +		data[id].sensor_id = id;
>> +		data[id].bgp = bgp;
>> +		data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
>> +		data[id].stat_offset = data[id].ctrl_offset +
>> +					K3_VTM_TMPSENS_STAT_OFFSET;
>> +
>> +		if (!workaround_needed)
>> +			goto prepare_lookup;
>> +		/* ref adc values for -40C, 30C & 125C respectively */
>> +		data[id].ref_adc_val[0] = MINUS40CREF;
>> +		data[id].ref_adc_val[1] = PLUS30CREF;
>> +		data[id].ref_adc_val[2] = PLUS125CREF;
>> +		get_efuse_values(id, &data[id], err, bgp);
>> +
>> +prepare_lookup:
>> +		if (id == 0 && workaround_needed) {
>> +			prep_lookup_table(err[0], err[1], err[2], 0);
>> +		} else if (id == 0 && !workaround_needed) {
>> +			for (j = 0; j < (sizeof(pvt_poly_golden) / 4); j++)
>> +				derived_array[j] = pvt_poly_golden[j];
>> +		}
>> +
>> +		val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
>> +		val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
>> +			K3_VTM_TMPSENS_CTRL_SOC |
>> +			K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
>> +		writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
>> +
>> +		bgp->ts_data[id] = &data[id];
>> +		data[id].ti_thermal =
>> +		devm_thermal_zone_of_sensor_register(bgp->dev, id,
>> +						     &data[id],
>> +						     &k3_of_thermal_ops);
>> +		if (IS_ERR(data[id].ti_thermal)) {
>> +			dev_err(bgp->dev, "thermal zone device is NULL\n");
>> +			ret = PTR_ERR(data[id].ti_thermal);
>> +			goto err_alloc;
>> +		}
>> +
>> +		reg_cnt++;
>> +
>> +		/* Initialize Previous temp */
>> +		k3_thermal_get_temp(&data[id], &data[id].prev_temp);
>> +	}
>> +
>> +	/*
>> +	 * Program TSHUT thresholds
>> +	 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
>> +	 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN  bit
>> +	 *         This is already taken care as per of init
>> +	 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN  bit
>> +	 */
>> +	high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
>> +	low_max = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
>> +
>> +	writel((low_max << 16) | high_max, data[0].bgp->cfg2_base +
>> +	       K3_VTM_MISC_CTRL2_OFFSET);
>> +	mdelay(100);
>> +	writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
>> +	       K3_VTM_MISC_CTRL_OFFSET);
>> +
>> +	platform_set_drvdata(pdev, bgp);
>> +
>> +#ifdef DEBUG_VTM
>> +	print_look_up_table(dev);
>> +#endif
>> +	return 0;
>> +
>> +err_alloc:
>> +	pm_runtime_put_sync(&pdev->dev);
>> +	pm_runtime_disable(&pdev->dev);
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
>> +{
>> +	pm_runtime_put_sync(&pdev->dev);
>> +	pm_runtime_disable(&pdev->dev);
>> +
>> +	return 0;
>> +}
>> +
>> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j721e_data = {
>> +	.workaround = 1,
>> +};
>> +
>> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j7200_data = {
>> +	.workaround = 0,
>> +};
>> +
>> +static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
>> +	{
>> +		.compatible = "ti,j721e-vtm",
>> +		.data = (void *)&k3_j72xx_bandgap_j721e_data,
>> +	},
>> +	{
>> +		.compatible = "ti,j7200-vtm",
>> +		.data = (void *)&k3_j72xx_bandgap_j7200_data,
>> +	},
>> +	{ /* sentinel */ },
>> +};
>> +MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
>> +
>> +static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
>> +	.probe = k3_j72xx_bandgap_probe,
>> +	.remove = k3_j72xx_bandgap_remove,
>> +	.driver = {
>> +		.name = "k3-j72xx-soc-thermal",
>> +		.of_match_table	= of_k3_j72xx_bandgap_match,
>> +	},
>> +};
>> +
>> +module_platform_driver(k3_j72xx_bandgap_sensor_driver);
>> +
>> +MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR("J Keerthy <[e-mail]>");
>>
> 
>

Daniel Lezcano Oct. 19, 2021, 9:08 p.m. UTC | #3

On 19/10/2021 20:17, J, KEERTHY wrote:
> 
> 
> On 10/19/2021 11:33 PM, Daniel Lezcano wrote:
>>
>> Hi Keerthy,
>>
>>
>> On 19/10/2021 18:06, Keerthy wrote:
>>> Add VTM thermal support. In the Voltage Thermal Management
>>> Module(VTM), K3 J72XX supplies a voltage reference and a temperature
>>> sensor feature that are gathered in the band gap voltage and
>>> temperature sensor (VBGAPTS) module. The band gap provides current and
>>> voltage reference for its internal circuits and other analog IP
>>> blocks. The analog-to-digital converter (ADC) produces an output value
>>> that is proportional to the silicon temperature.
>>>
>>> Currently reading temperatures only is supported.  There are no
>>> active/passive cooling agent supported.
>>>
>>> J721e SoCs have errata i2128: https://www.ti.com/lit/pdf/sprz455
>>>
>>> The VTM Temperature Monitors (TEMPSENSORs) are trimmed during
>>> production,
>>> with the resulting values stored in software-readable registers.
>>> Software
>>> should use these  register values when translating the Temperature
>>> Monitor output codes to temperature values.
>>>
>>> It has an involved workaround. Software needs to read the error codes
>>> for
>>> -40C, 30C, 125C from the efuse for each device & derive a new look up
>>> table
>>> for adc to temperature conversion. Involved calculating slopes &
>>> constants
>>> using 3 different straight line equations with adc refernce codes as the
>>> y-axis & error codes in the x-axis.
>>>
>>> -40C to 30C
>>> 30C to 125C
>>> 125C to 150C
>>>
>>> With the above 2 line equations we derive the full look-up table to
>>> workaround the errata i2128 for j721e SoC.
>>>
>>> Tested temperature reading on J721e SoC & J7200 SoC.
>>
>> I take some the time to trace the values in the array below and it
>> results in a very nice curve, almost flat.
>>
>> That make me think the values are generated from a polynomial equation
>> like the other driver.
>>
>> So instead of adding a full blob of array here which are 8KB in total in
>> this file, why not generate the array dynamically at probe time ?
> 
> Daniel,
> 
> First of all thanks for the quick feedback!
> 
> Warning: The below document is 200 odd MB document :-)
> 
> TRM: http://www.ti.com/lit/pdf/spruil1
> 
> Page: 2364
> 
> y = a4 × x4 + a3 × x3 + a2 × x2 + a1 × x + a0
> 
> Temperature = f(Code) °C
> 
> a4 = -9.2627E-12
> a3 = 6.0373E-08
> a2 = -1.7058E-04
> a1 = 3.2512E-01
> a0 = -4.9002E+01
> 
> I really do not want to implement that function in the driver. Hope you
> agree with me.

s64 integer:

a4=-92627
a3=603730000
a2=-1705800000000
a1=3251200000000000
a0=-490019999999999936

AFAICT, the result with the program below gives the same values than the
ones in the table. So far it is possible.

> Similarly we have the other table having a different polynomial.
> 
> I used python to compute the tables from the equations.

Here is a C program to convert from floating point, to integer
polynomial equation. Just multiply all factors by the same value which
makes the smaller factor an integer.

Here it is -9.2627 x 10e-12

So it has to be multiplied by 10e12 => -9.2627, then 10e4 => -92627, so
the factors need to be multiplied by 10e16
The result of the equation needs then divided by 10e16 again. But as we
want mC°, that will 10e13 instead.

Small program does:

myequation <index>

For example:

myequation 500

77.880706
77880
my integer factors:
a4=-92627
a3=603730000
a2=-1705800000000
a1=3251200000000000
a0=-490019999999999936


#include <math.h>
#include <stdio.h>
#include <stdlib.h>

/*



 * power-of kernel function



 */
unsigned long long int_pow(unsigned long long base, unsigned int exp)
{
        unsigned long long result = 1;

        while (exp) {
                if (exp & 1)
                        result *= base;
                exp >>= 1;
                base *= base;
        }

        return result;
}

int main(int argc, char *argv[])
{
        double x, y;

        double a4 = -9.2627 * pow(10, -12);
        double a3 = 6.0373 * pow(10, -8);
        double a2 = -1.7058 * pow(10, -4);
        double a1 = 3.2512 * pow(10, -1);
        double a0 = -4.9002 * 10;

        long long X, Y;

	/*
	 * Put at the power-of in order to have the smaller factor to be
	 * an integer. For a4 we have to elevate at the power of 16.
	 */
        long long A4 = a4 * int_pow(10, 16);
        long long A3 = a3 * int_pow(10, 16);
        long long A2 = a2 * int_pow(10, 16);
        long long A1 = a1 * int_pow(10, 16);
        long long A0 = a0 * int_pow(10, 16);

        if (argc < 2) {
                fprintf(stderr, "%s <index>\n", argv[0]);
                return 1;
        }

        x = atof(argv[1]);
        y = a4 * pow(x, 4) + a3 * pow(x, 3) + a2 * x * x + a1 * x + a0;

        printf("%f\n", y);

        X = atoi(argv[1]);
        Y = A4 * int_pow(X, 4) + A3 * int_pow(X, 3) + A2 * int_pow(X, 2)
+ A1 * X + A0;

	/*
	 * The polynomial equation returns the value in degree with a
	 * floating point. The thermal framework deals with mC°, so
	 * divide by the power of 13 instead of 16.
	 */
        printf("%lld\n", Y / (long long)int_pow(10, 13));

        printf("my integer
factors:\na4=%lld\na3=%lld\na2=%lld\na1=%lld\na0=%lld\n",
               A4, A3, A2, A1, A0);

        return 0;
}

Logically, a simple function could be:

s64 myfactors[] = {
	-490019999999999936,
	3251200000000000,
	-1705800000000,
	603730000,
	-92627
};

int myvalue(int index, s64 *factors, int nr_factors, int reduction)
{
	s64 value = 0;
	int i;
	for (i = 0; i < nr_factors; i++) {
		value += factors[i] * int_pow(index, i);

	return (int)(value / int_pow(10, reduction));
}

void init_mytable(void)
{
	int *mytable;
	const int size = 1024;
	int i;

	mytable = kzalloc(sizeof(*mytable) * size);

	for (i = 0; i < size; i++) {
		mytable[i] = myvalue(i, myfactors,
				ARRAY_SIZE(myfactors), 13);
	}
}

What do you think ?

>> That will save space on disk and memory.
>>
>>
>>
>>> Signed-off-by: Keerthy <[e-mail]>
>>> ---
>>>   drivers/thermal/Makefile           |   2 +-
>>>   drivers/thermal/k3_j72xx_bandgap.c | 772 +++++++++++++++++++++++++++++
>>>   2 files changed, 773 insertions(+), 1 deletion(-)
>>>   create mode 100644 drivers/thermal/k3_j72xx_bandgap.c
>>>
>>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>>> index 82fc3e616e54..6dcaf2028ddc 100644
>>> --- a/drivers/thermal/Makefile
>>> +++ b/drivers/thermal/Makefile
>>> @@ -28,7 +28,7 @@ thermal_sys-$(CONFIG_CPU_IDLE_THERMAL)    +=
>>> cpuidle_cooling.o
>>>   # devfreq cooling
>>>   thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
>>>   -obj-$(CONFIG_K3_THERMAL)    += k3_bandgap.o
>>> +obj-$(CONFIG_K3_THERMAL)    += k3_bandgap.o k3_j72xx_bandgap.o
>>>   # platform thermal drivers
>>>   obj-y                += broadcom/
>>>   obj-$(CONFIG_THERMAL_MMIO)        += thermal_mmio.o
>>> diff --git a/drivers/thermal/k3_j72xx_bandgap.c
>>> b/drivers/thermal/k3_j72xx_bandgap.c
>>> new file mode 100644
>>> index 000000000000..1aa048221291
>>> --- /dev/null
>>> +++ b/drivers/thermal/k3_j72xx_bandgap.c
>>> @@ -0,0 +1,772 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * TI Bandgap temperature sensor driver for J72XX SoC Family
>>> + *
>>> + * Copyright (C) 2021 Texas Instruments Incorporated -
>>> http://www.ti.com/
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/init.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/pm_runtime.h>
>>> +#include <linux/err.h>
>>> +#include <linux/types.h>
>>> +#include <linux/spinlock.h>
>>> +#include <linux/of_platform.h>
>>> +#include <linux/io.h>
>>> +#include <linux/thermal.h>
>>> +#include <linux/of.h>
>>> +#include <linux/delay.h>
>>> +
>>> +#define K3_VTM_DEVINFO_PWR0_OFFSET        0x4
>>> +#define K3_VTM_DEVINFO_PWR0_CVD_CT_MASK        0xf
>>> +#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK    0xf0
>>> +#define K3_VTM_TMPSENS0_CTRL_OFFSET        0x300
>>> +#define K3_VTM_MISC_CTRL_OFFSET            0xc
>>> +#define K3_VTM_TMPSENS_STAT_OFFSET        0x8
>>> +#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN        0x1
>>> +#define K3_VTM_MISC_CTRL2_OFFSET        0x10
>>> +#define K3_VTM_REGS_PER_TS            0x10
>>> +#define K3_VTM_TS_STAT_DTEMP_MASK        0x3ff
>>> +#define K3_VTM_MAX_NUM_TS            8
>>> +#define K3_VTM_TMPSENS_CTRL_CBIASSEL        BIT(0)
>>> +#define K3_VTM_TMPSENS_CTRL_SOC            BIT(5)
>>> +#define K3_VTM_TMPSENS_CTRL_CLRZ        BIT(6)
>>> +#define K3_VTM_TMPSENS_CTRL_CLKON_REQ        BIT(7)
>>> +#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN    BIT(11)
>>> +
>>> +#define K3_VTM_CORRECTION_TEMP_CNT        3
>>> +
>>> +#define K3_VTM_ADC_BEGIN_VAL            6
>>> +#define K3_VTM_ADC_END_VAL            944
>>> +
>>> +#define MINUS40CREF                5
>>> +#define PLUS30CREF                253
>>> +#define PLUS125CREF                730
>>> +#define PLUS150CREF                940
>>> +
>>> +#define MAX_TEMP                123000
>>> +#define COOL_DOWN_TEMP                105000
>>> +
>>> +//#define DEBUG_VTM
>>> +
>>> +static int derived_array[1024];
>>> +
>>> +/* Reference Look up table when work around is NOT needed */
>>> +static const int pvt_poly_golden[] = {
>>> +    -49002, -48677, -48352, -48028, -47704, -47381, -47057, -46734,
>>> -46412,
>>> +    -46090, -45768, -45446, -45125, -44804, -44484, -44163, -43844,
>>> -43524,
>>> +    -43205, -42886, -42567, -42249, -41931, -41614, -41297, -40980,
>>> -40663,
>>> +    -40347, -40031, -39716, -39400, -39085, -38771, -38457, -38143,
>>> -37829,
>>> +    -37516, -37203, -36890, -36578, -36266, -35955, -35643, -35332,
>>> -35022,
>>> +    -34712, -34402, -34092, -33783, -33474, -33165, -32857, -32549,
>>> -32241,
>>> +    -31934, -31626, -31320, -31013, -30707, -30401, -30096, -29791,
>>> -29486,
>>> +    -29182, -28877, -28573, -28270, -27967, -27664, -27361, -27059,
>>> -26757,
>>> +    -26455, -26154, -25853, -25552, -25252, -24952, -24652, -24353,
>>> -24054,
>>> +    -23755, -23456, -23158, -22860, -22563, -22265, -21968, -21672,
>>> -21376,
>>> +    -21079, -20784, -20488, -20193, -19899, -19604, -19310, -19016,
>>> -18723,
>>> +    -18429, -18136, -17844, -17551, -17259, -16968, -16676, -16385,
>>> -16094,
>>> +    -15804, -15514, -15224, -14934, -14645, -14356, -14067, -13779,
>>> -13491,
>>> +    -13203, -12916, -12628, -12342, -12055, -11769, -11483, -11197,
>>> -10912,
>>> +    -10627, -10342, -10057, -9773, -9489, -9206, -8922, -8639,
>>> -8357, -8074,
>>> +    -7792, -7510, -7229, -6947, -6666, -6386, -6105, -5825, -5546,
>>> -5266,
>>> +    -4987, -4708, -4429, -4151, -3873, -3595, -3318, -3041, -2764,
>>> -2487,
>>> +    -2211, -1935, -1659, -1384, -1108, -834, -559, -285, -11, 263,
>>> 537, 810,
>>> +    1083, 1355, 1628, 1900, 2171, 2443, 2714, 2985, 3255, 3526,
>>> 3796, 4066,
>>> +    4335, 4604, 4873, 5142, 5410, 5679, 5946, 6214, 6481, 6748,
>>> 7015, 7281,
>>> +    7548, 7813, 8079, 8344, 8609, 8874, 9139, 9403, 9667, 9931, 10194,
>>> +    10457, 10720, 10983, 11245, 11507, 11769, 12030, 12292, 12553,
>>> 12813,
>>> +    13074, 13334, 13594, 13854, 14113, 14372, 14631, 14889, 15148,
>>> 15406,
>>> +    15664, 15921, 16178, 16435, 16692, 16948, 17205, 17461, 17716,
>>> 17972,
>>> +    18227, 18482, 18736, 18991, 19245, 19498, 19752, 20005, 20258,
>>> 20511,
>>> +    20764, 21016, 21268, 21520, 21771, 22022, 22273, 22524, 22774,
>>> 23025,
>>> +    23274, 23524, 23774, 24023, 24272, 24520, 24769, 25017, 25265,
>>> 25512,
>>> +    25760, 26007, 26254, 26500, 26747, 26993, 27239, 27484, 27730,
>>> 27975,
>>> +    28220, 28464, 28708, 28953, 29196, 29440, 29683, 29927, 30169,
>>> 30412,
>>> +    30654, 30896, 31138, 31380, 31621, 31862, 32103, 32344, 32584,
>>> 32824,
>>> +    33064, 33304, 33543, 33783, 34022, 34260, 34499, 34737, 34975,
>>> 35213,
>>> +    35450, 35687, 35924, 36161, 36397, 36634, 36870, 37105, 37341,
>>> 37576,
>>> +    37811, 38046, 38281, 38515, 38749, 38983, 39217, 39450, 39683,
>>> 39916,
>>> +    40149, 40381, 40614, 40846, 41077, 41309, 41540, 41771, 42002,
>>> 42233,
>>> +    42463, 42693, 42923, 43153, 43382, 43611, 43840, 44069, 44297,
>>> 44526,
>>> +    44754, 44981, 45209, 45436, 45663, 45890, 46117, 46343, 46570,
>>> 46796,
>>> +    47021, 47247, 47472, 47697, 47922, 48147, 48371, 48595, 48819,
>>> 49043,
>>> +    49266, 49490, 49713, 49935, 50158, 50380, 50603, 50824, 51046,
>>> 51268,
>>> +    51489, 51710, 51931, 52151, 52372, 52592, 52812, 53031, 53251,
>>> 53470,
>>> +    53689, 53908, 54127, 54345, 54563, 54781, 54999, 55217, 55434,
>>> 55651,
>>> +    55868, 56085, 56301, 56517, 56733, 56949, 57165, 57380, 57595,
>>> 57810,
>>> +    58025, 58239, 58454, 58668, 58882, 59095, 59309, 59522, 59735,
>>> 59948,
>>> +    60160, 60373, 60585, 60797, 61009, 61220, 61432, 61643, 61854,
>>> 62064,
>>> +    62275, 62485, 62695, 62905, 63115, 63324, 63534, 63743, 63952,
>>> 64160,
>>> +    64369, 64577, 64785, 64993, 65200, 65408, 65615, 65822, 66029,
>>> 66236,
>>> +    66442, 66648, 66854, 67060, 67266, 67471, 67676, 67881, 68086,
>>> 68291,
>>> +    68495, 68699, 68903, 69107, 69311, 69514, 69717, 69920, 70123,
>>> 70326,
>>> +    70528, 70730, 70932, 71134, 71336, 71537, 71738, 71939, 72140,
>>> 72341,
>>> +    72541, 72742, 72942, 73142, 73341, 73541, 73740, 73939, 74138,
>>> 74337,
>>> +    74535, 74733, 74932, 75130, 75327, 75525, 75722, 75919, 76116,
>>> 76313,
>>> +    76510, 76706, 76902, 77098, 77294, 77490, 77685, 77881, 78076,
>>> 78271,
>>> +    78465, 78660, 78854, 79048, 79242, 79436, 79630, 79823, 80016,
>>> 80210,
>>> +    80402, 80595, 80788, 80980, 81172, 81364, 81556, 81747, 81939,
>>> 82130,
>>> +    82321, 82512, 82702, 82893, 83083, 83273, 83463, 83653, 83843,
>>> 84032,
>>> +    84221, 84410, 84599, 84788, 84976, 85165, 85353, 85541, 85728,
>>> 85916,
>>> +    86103, 86291, 86478, 86665, 86851, 87038, 87224, 87411, 87597,
>>> 87782,
>>> +    87968, 88154, 88339, 88524, 88709, 88894, 89078, 89263, 89447,
>>> 89631,
>>> +    89815, 89999, 90182, 90366, 90549, 90732, 90915, 91098, 91280,
>>> 91463,
>>> +    91645, 91827, 92009, 92191, 92372, 92554, 92735, 92916, 93097,
>>> 93277,
>>> +    93458, 93638, 93818, 93998, 94178, 94358, 94537, 94717, 94896,
>>> 95075,
>>> +    95254, 95433, 95611, 95790, 95968, 96146, 96324, 96501, 96679,
>>> 96856,
>>> +    97033, 97211, 97387, 97564, 97741, 97917, 98093, 98269, 98445,
>>> 98621,
>>> +    98797, 98972, 99147, 99322, 99497, 99672, 99847, 100021, 100196,
>>> 100370,
>>> +    100544, 100718, 100891, 101065, 101238, 101411, 101584, 101757,
>>> 101930,
>>> +    102103, 102275, 102447, 102619, 102791, 102963, 103135, 103306,
>>> 103478,
>>> +    103649, 103820, 103991, 104161, 104332, 104502, 104673, 104843,
>>> 105013,
>>> +    105182, 105352, 105522, 105691, 105860, 106029, 106198, 106367,
>>> 106535,
>>> +    106704, 106872, 107040, 107208, 107376, 107544, 107711, 107878,
>>> 108046,
>>> +    108213, 108380, 108546, 108713, 108880, 109046, 109212, 109378,
>>> 109544,
>>> +    109710, 109875, 110041, 110206, 110371, 110536, 110701, 110866,
>>> 111030,
>>> +    111195, 111359, 111523, 111687, 111851, 112015, 112178, 112342,
>>> 112505,
>>> +    112668, 112831, 112994, 113157, 113319, 113482, 113644, 113806,
>>> 113968,
>>> +    114130, 114292, 114453, 114615, 114776, 114937, 115098, 115259,
>>> 115420,
>>> +    115580, 115741, 115901, 116061, 116221, 116381, 116541, 116701,
>>> 116860,
>>> +    117019, 117179, 117338, 117497, 117655, 117814, 117973, 118131,
>>> 118289,
>>> +    118447, 118605, 118763, 118921, 119078, 119236, 119393, 119550,
>>> 119707,
>>> +    119864, 120021, 120178, 120334, 120490, 120647, 120803, 120959,
>>> 121115,
>>> +    121270, 121426, 121581, 121737, 121892, 122047, 122202, 122356,
>>> 122511,
>>> +    122666, 122820, 122974, 123128, 123282, 123436, 123590, 123744,
>>> 123897,
>>> +    124050, 124204, 124357, 124510, 124662, 124815, 124968, 125120,
>>> 125273,
>>> +    125425, 125577, 125729, 125881, 126032, 126184, 126335, 126487,
>>> 126638,
>>> +    126789, 126940, 127091, 127241, 127392, 127542, 127693, 127843,
>>> 127993,
>>> +    128143, 128293, 128442, 128592, 128741, 128891, 129040, 129189,
>>> 129338,
>>> +    129487, 129635, 129784, 129932, 130081, 130229, 130377, 130525,
>>> 130673,
>>> +    130821, 130968, 131116, 131263, 131410, 131558, 131705, 131851,
>>> 131998,
>>> +    132145, 132291, 132438, 132584, 132730, 132876, 133022, 133168,
>>> 133314,
>>> +    133460, 133605, 133750, 133896, 134041, 134186, 134331, 134476,
>>> 134620,
>>> +    134765, 134909, 135054, 135198, 135342, 135486, 135630, 135773,
>>> 135917,
>>> +    136061, 136204, 136347, 136491, 136634, 136777, 136919, 137062,
>>> 137205,
>>> +    137347, 137490, 137632, 137774, 137916, 138058, 138200, 138342,
>>> 138483,
>>> +    138625, 138766, 138907, 139049, 139190, 139331, 139471, 139612,
>>> 139753,
>>> +    139893, 140034, 140174, 140314, 140454, 140594, 140734, 140874,
>>> 141013,
>>> +    141153, 141292, 141432, 141571, 141710, 141849, 141988, 142127,
>>> 142265,
>>> +    142404, 142542, 142681, 142819, 142957, 143095, 143233, 143371,
>>> 143509,
>>> +    143646, 143784, 143921, 144058, 144196, 144333, 144470, 144607,
>>> 144743,
>>> +    144880, 145017, 145153, 145289, 145426, 145562, 145698, 145834,
>>> 145970,
>>> +    146105, 146241, 146377, 146512, 146647, 146783, 146918, 147053,
>>> 147188,
>>> +    147323, 147457, 147592, 147727, 147861, 147995, 148130, 148264,
>>> 148398,
>>> +    148532, 148666, 148799, 148933, 149067, 149200, 149333, 149467,
>>> 149600,
>>> +    149733, 149866, 149999, 150131, 150264, 150397, 150529, 150661,
>>> 150794,
>>> +    150926, 151058, 151190, 151322, 151454, 151585, 151717, 151848,
>>> 151980,
>>> +    152111,    152242, 152373, 152505, 152635, 152766, 152897,
>>> 153028, 153158,
>>> +    153289, 153419, 153549, 153680, 153810, 153940, 154070, 154199,
>>> 154329,
>>> +    154459, 154588, 154718, 154847, 154976, 155105, 155235, 155363,
>>> 155492,
>>> +    155621, 155750, 155879, 156007, 156135, 156264, 156392, 156520,
>>> 156648,
>>> +    156776, 156904, 157032, 157160, 157287, 157415, 157542, 157670,
>>> 157797,
>>> +    157924, 158051, 158178, 158305, 158432, 158559, 158685, 158812,
>>> 158938,
>>> +    159065, 159191, 159317, 159443, 159569,
>>> +};
>>> +
>>> +/* Reference Look up table when work around is needed */
>>> +static const int pvt_poly[] = {
>>> +    -41523, -41210, -40898, -40586, -40274, -39963, -39651,
>>> -39340,    -39029,
>>> +    -38718, -38408, -38098, -37788, -37478, -37168, -36859, -36550,
>>> -36241,
>>> +    -35933, -35624, -35316, -35008, -34701, -34393, -34086, -33779,
>>> -33472,
>>> +    -33166, -32859, -32553, -32247, -31942, -31636, -31331, -31026,
>>> -30722,
>>> +    -30417, -30113, -29809, -29505, -29202, -28899, -28596, -28293,
>>> -27990,
>>> +    -27688, -27386, -27084, -26782, -26481, -26179, -25878, -25578,
>>> -25277,
>>> +    -24977, -24677, -24377, -24078, -23778, -23479, -23180, -22882,
>>> -22583,
>>> +    -22285, -21987, -21689, -21392, -21095, -20797, -20501, -20204,
>>> -19908,
>>> +    -19612, -19316, -19020, -18725, -18430, -18135, -17840, -17545,
>>> -17251,
>>> +    -16957, -16663, -16370, -16077, -15783, -15491, -15198,   
>>> -14906, -14613,
>>> +    -14321, -14030, -13738, -13447, -13156, -12865, -12575, -12284,
>>> -11994,
>>> +    -11704, -11415, -11125, -10836, -10547, -10259, -9970, -9682,
>>> -9394,
>>> +    -9106, -8819, -8531, -8244, -7957, -7671, -7384, -7098, -6812,
>>> -6527,
>>> +    -6241, -5956, -5671, -5386, -5102, -4817, -4533, -4250, -3966,
>>> -3683,
>>> +    -3399, -3117, -2834, -2551, -2269, -1987, -1706, -1424, -1143,
>>> -862,
>>> +    -581, -300, -20, 260, 540, 820, 1099, 1378, 1657, 1936, 2215, 2493,
>>> +    2771, 3049, 3326, 3604, 3881, 4158, 4434, 4711, 4987, 5263,
>>> 5539, 5814,
>>> +    6089, 6364, 6639, 6914, 7188, 7462, 7736, 8010, 8283, 8556,
>>> 8829, 9102,
>>> +    9374, 9647, 9919, 10191, 10462, 10733, 11005, 11275, 11546, 11816,
>>> +    12087, 12357, 12626, 12896, 13165, 13434, 13703, 13971, 14240,
>>> 14508,
>>> +    14776, 15043, 15311, 15578, 15845, 16111, 16378, 16644, 16910,
>>> 17176,
>>> +    17441, 17707, 17972, 18237, 18501, 18766, 19030, 19294, 19557,
>>> 19821,
>>> +    20084, 20347, 20610, 20872, 21135, 21397, 21658, 21920, 22181,
>>> 22443,
>>> +    22703, 22964, 23225, 23485, 23745, 24005, 24264, 24523, 24782,
>>> 25041,
>>> +    25300, 25558, 25816, 26074, 26332, 26589, 26846, 27103, 27360,
>>> 27617,
>>> +    27873, 28129, 28385, 28640, 28896, 29151, 29406, 29660, 29915,
>>> 30169,
>>> +    30423, 30677, 30930, 31183, 31437, 31689, 31942, 32194, 32446,
>>> 32698,
>>> +    32950, 33201, 33452, 33703, 33954, 34205, 34455, 34705, 34955,
>>> 35204,
>>> +    35454, 35703, 35952, 36200, 36449, 36697, 36945, 37192, 37440,
>>> 37687,
>>> +    37934, 38181, 38427, 38674, 38920, 39166, 39411, 39657, 39902,
>>> 40147,
>>> +    40391, 40636, 40880, 41124, 41368, 41611, 41855, 42098, 42341,
>>> 42583,
>>> +    42826, 43068, 43310, 43551, 43793, 44034, 44275, 44516, 44756,
>>> 44997,
>>> +    45237, 45477, 45716, 45956, 46195, 46434, 46672, 46911, 47149,
>>> 47387,
>>> +    47625, 47862, 48100, 48337, 48573, 48810, 49046, 49282, 49518,
>>> 49754,
>>> +    49989, 50225, 50460, 50694, 50929, 51163, 51397, 51631, 51865,
>>> 52098,
>>> +    52331, 52564, 52797, 53029, 53261, 53493, 53725, 53956, 54188,
>>> 54419,
>>> +    54650, 54880, 55110, 55341, 55570, 55800, 56030, 56259, 56488,
>>> 56716,
>>> +    56945, 57173, 57401, 57629, 57856, 58084, 58311, 58538, 58764,
>>> 58991,
>>> +    59217, 59443, 59669, 59894, 60119, 60344, 60569, 60794, 61018,
>>> 61242,
>>> +    61466, 61690, 61913, 62136, 62359, 62582, 62804, 63026, 63249,
>>> 63470,
>>> +    63692, 63913, 64134, 64355, 64576, 64796, 65016, 65236, 65456,
>>> 65675,
>>> +    65894, 66113, 66332, 66551, 66769, 66987, 67205, 67423, 67640,
>>> 67857,
>>> +    68074, 68291, 68507, 68723, 68939, 69155, 69371, 69586, 69801,
>>> 70016,
>>> +    70230, 70445, 70659, 70873, 71086, 71300, 71513, 71726, 71939,
>>> 72151,
>>> +    72364, 72576, 72787, 72999, 73210, 73422, 73632, 73843, 74053,
>>> 74264,
>>> +    74474, 74683, 74893, 75102, 75311, 75520, 75729, 75937, 76145,
>>> 76353,
>>> +    76561, 76768, 76975, 77182, 77389, 77595, 77802, 78008, 78213,
>>> 78419,
>>> +    78624, 78829, 79034, 79239, 79443, 79647, 79851, 80055, 80259,
>>> 80462,
>>> +    80665, 80868, 81070, 81273, 81475, 81676, 81878, 82079, 82281,
>>> 82482,
>>> +    82682, 82883, 83083, 83283, 83483, 83682, 83882, 84081, 84280,
>>> 84478,
>>> +    84677, 84875, 85073, 85270, 85468, 85665, 85862, 86059, 86255,
>>> 86452,
>>> +    86648, 86844, 87039, 87234, 87430, 87625, 87819, 88014, 88208,
>>> 88402,
>>> +    88596, 88789, 88982, 89175, 89368, 89561, 89753, 89945, 90137,
>>> 90329,
>>> +    90520, 90712, 90903, 91093, 91284, 91474, 91664, 91854, 92044,
>>> 92233,
>>> +    92422, 92611, 92800, 92988, 93176, 93364, 93552, 93739, 93927,
>>> 94114,
>>> +    94301, 94487, 94673, 94860, 95045, 95231, 95417, 95602, 95787,
>>> 95971,
>>> +    96156, 96340, 96524, 96708, 96892, 97075, 97258, 97441, 97624,
>>> 97806,
>>> +    97988, 98170, 98352, 98533, 98714, 98895, 99076, 99257, 99437,
>>> 99617,
>>> +    99797, 99977, 100156, 100335, 100514, 100693, 100871, 101050,
>>> 101228,
>>> +    101405, 101583, 101760, 101937, 102114, 102291, 102467, 102643,
>>> 102819,
>>> +    102995, 103170, 103346, 103521, 103695, 103870, 104044, 104218,
>>> 104392,
>>> +    104566, 104739, 104912, 105085, 105258, 105430, 105603, 105775,
>>> 105946,
>>> +    106118, 106289, 106460, 106631, 106802, 106972, 107142, 107312,
>>> 107482,
>>> +    107651, 107820, 107989, 108158, 108327, 108495, 108663, 108831,
>>> 108998,
>>> +    109166, 109333, 109500, 109666, 109833, 109999, 110165, 110331,
>>> 110496,
>>> +    110661, 110827, 110991, 111156, 111320, 111484, 111648, 111812,
>>> 111975,
>>> +    112139, 112301, 112464, 112627, 112789, 112951, 113113, 113274,
>>> 113436,
>>> +    113597, 113758, 113918, 114079, 114239, 114399, 114559, 114718,
>>> 114877,
>>> +    115036, 115195, 115354, 115512, 115670, 115828, 115986, 116143,
>>> 116300,
>>> +    116457, 116614, 116770, 116926, 117082, 117238, 117394, 117549,
>>> 117704,
>>> +    117859, 118014, 118168, 118322, 118476, 118630, 118783, 118937,
>>> 119090,
>>> +    119242, 119395, 119547, 119699, 119851, 120003, 120154, 120305,
>>> 120456,
>>> +    120607, 120757, 120907, 121057, 121207, 121357, 121506, 121655,
>>> 121804,
>>> +    121953, 122101, 122249, 122397, 122545, 122692, 122839, 122986,
>>> 123133,
>>> +    123280, 123426, 123572, 123718, 123863, 124009, 124154, 124299,
>>> 124443,
>>> +    124588, 124732, 124876, 125020, 125163, 125306, 125449, 125592,
>>> 125735,
>>> +    125877, 126019, 126161, 126303, 126444, 126585, 126726, 126867,
>>> 127008,
>>> +    127148, 127288, 127428, 127567, 127707, 127846, 127985, 128123,
>>> 128262,
>>> +    128400, 128538, 128676, 128813, 128950, 129087, 129224, 129361,
>>> 129497,
>>> +    129633, 129769, 129905, 130040, 130175, 130310, 130445, 130579,
>>> 130713,
>>> +    130847, 130981, 131115, 131248, 131381, 131514, 131647, 131779,
>>> 131911,
>>> +    132043, 132175, 132306, 132438, 132569, 132699, 132830, 132960,
>>> 133090,
>>> +    133220, 133350, 133479, 133608, 133737, 133866, 133994, 134123,
>>> 134251,
>>> +    134378, 134506, 134633, 134760, 134887, 135014, 135140, 135266,
>>> 135392,
>>> +    135518, 135643, 135768, 135893, 136018, 136143, 136267, 136391,
>>> 136515,
>>> +    136638, 136762, 136885, 137008, 137130, 137253, 137375, 137497,
>>> 137619,
>>> +    137740, 137862, 137983, 138103, 138224, 138344, 138464, 138584,
>>> 138704,
>>> +    138823, 138943, 139062, 139180, 139299, 139417, 139535, 139653,
>>> 139770,
>>> +    139888, 140005, 140122, 140238, 140355, 140471, 140587, 140703,
>>> 140818,
>>> +    140933, 141048, 141163, 141278, 141392, 141506, 141620, 141734,
>>> 141847,
>>> +    141960, 142073, 142186, 142298, 142411, 142523, 142634, 142746,
>>> 142857,
>>> +    142968, 143079, 143190, 143300, 143410, 143520, 143630, 143740,
>>> 143849,
>>> +    143958, 144067, 144175, 144283, 144391, 144499, 144607, 144714,
>>> 144821,
>>> +    144928, 145035, 145142, 145248, 145354, 145459, 145565, 145670,
>>> 145775,
>>> +    145880, 145985, 146089, 146193, 146297, 146401, 146504, 146608,
>>> 146711,
>>> +    146813, 146916, 147018, 147120, 147222, 147324, 147425, 147526,
>>> 147627,
>>> +    147728, 147828, 147928, 148028, 148128, 148228, 148327, 148426,
>>> 148525,
>>> +    148623, 148722, 148820, 148918, 149015, 149113, 149210, 149307,
>>> 149404,
>>> +    149500, 149596, 149692, 149788, 149884, 149979, 150074, 150169,
>>> 150264,
>>> +    150358, 150452, 150546, 150640, 150733, 150827, 150920, 151013,
>>> 151105,
>>> +    151197, 151290, 151381, 151473, 151564, 151656, 151747, 151837,
>>> 151928,
>>> +    152018, 152108, 152198, 152287, 152377, 152466, 152555, 152643,
>>> 152732,
>>> +    152820, 152908, 152995, 153083, 153170, 153257, 153344, 153430,
>>> 153517,
>>> +    153603, 153689, 153774, 153860, 153945, 154030, 154114, 154199,
>>> 154283,
>>> +    154367, 154451, 154534, 154618, 154701, 154784, 154866, 154949,
>>> 155031,
>>> +    155113, 155194, 155276, 155357, 155438, 155519, 155599, 155680,
>>> 155760,
>>> +    155839, 155919, 155998, 156078, 156156, 156235, 156314, 156392,
>>> 156470,
>>> +    156547, 156625, 156702, 156779, 156856, 156933, 157009, 157085,
>>> 157161,
>>> +};
>>> +
>>> +static void fill_table(int err1, int err2, int ref1, int ref2, int
>>> idx1,
>>> +               int idx2)
>>> +{
>>> +    int m, c, num, den, i, err;
>>> +
>>> +    /**
>>> +     * Calculate the slope with adc values read from the register
>>> +     * as the y-axis param and err in adc value as x-axis param
>>> +     */
>>> +    if (err1 != err2) {
>>> +        num = ref2 - ref1;
>>> +        den = err2 - err1;
>>> +        m = num / den;
>>> +        c = ref2 - m * err2;
>>> +        for (i = idx1; i <= idx2; i++) {
>>> +            err = (i - c) / m;
>>> +            if (((i + err1) < 0) || ((i + err1) > 1023))
>>> +                continue;
>>> +            derived_array[i] = pvt_poly[i + err];
>>> +        }
>>> +    } else { /* Constant error take care of divide by zero */
>>> +        for (i = idx1; i < idx2; i++) {
>>> +            if (((i + err1) < 0) || ((i + err1) > 1023))
>>> +                continue;
>>> +            derived_array[i] = pvt_poly[i + err1];
>>> +        }
>>> +    }
>>> +}
>>> +
>>> +static int prep_lookup_table(int minus40cerr, int plus30cerr, int
>>> plus125cerr,
>>> +                 int plus150cerr)
>>> +{
>>> +    int start_temp, inc, i;
>>> +
>>> +    /* Fill up the lookup table region -40C to +30C */
>>> +    fill_table(minus40cerr, plus30cerr, MINUS40CREF, PLUS30CREF, 0,
>>> +           PLUS30CREF);
>>> +    /* Fill up the lookup table region +30C to +125C */
>>> +    fill_table(plus30cerr, plus125cerr, PLUS30CREF, PLUS125CREF,
>>> PLUS30CREF,
>>> +           PLUS125CREF);
>>> +    /* Fill up the lookup table region +125C to +150C */
>>> +    fill_table(plus125cerr, plus150cerr, PLUS125CREF, PLUS150CREF,
>>> PLUS125CREF,
>>> +           PLUS150CREF);
>>> +
>>> +    /* Get to the first valid temperature */
>>> +    i = 0;
>>> +    while (!derived_array[i])
>>> +        i++;
>>> +
>>> +    start_temp = i;
>>> +    /*
>>> +     * Get to the last zero index and back fill the temperature for
>>> +     * sake of continuity
>>> +     */
>>> +    if (i) {
>>> +        /* 300 milli celsius steps */
>>> +        while (i--)
>>> +            derived_array[i] = derived_array[i + 1] - 300;
>>> +        /* case 0 */
>>> +        derived_array[i] = derived_array[i + 1] - 300;
>>> +    }
>>> +
>>> +    /*
>>> +     * Fill the last trailing 0s which are unfilled with increments of
>>> +     * 100 milli celsius till 1023 code
>>> +     */
>>> +    i = 1023;
>>> +    while (!derived_array[i])
>>> +        i--;
>>> +
>>> +    i++;
>>> +    inc = 1;
>>> +    while (i < 1024) {
>>> +        derived_array[i] = derived_array[i - 1] + inc * 100;
>>> +        i++;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +struct k3_thermal_data;
>>> +
>>> +struct k3_j72xx_bandgap {
>>> +    struct device *dev;
>>> +    void __iomem *base;
>>> +    void __iomem *cfg2_base;
>>> +    void __iomem *fuse_base;
>>> +    const struct k3_j72xx_bandgap_data    *conf;
>>> +    spinlock_t lock; /* shields this struct */
>>> +    int ts_cnt;
>>> +    struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
>>> +};
>>> +
>>> +/* common data structures */
>>> +struct k3_thermal_data {
>>> +    struct thermal_zone_device *ti_thermal;
>>> +    struct thermal_cooling_device *cool_dev;
>>> +    struct k3_j72xx_bandgap *bgp;
>>> +    enum thermal_device_mode mode;
>>> +    int sensor_id;
>>> +    u32 ctrl_offset;
>>> +    u32 stat_offset;
>>> +    int prev_temp;
>>> +    int ct_offsets[K3_VTM_CORRECTION_TEMP_CNT];
>>> +    int ct_bm[K3_VTM_CORRECTION_TEMP_CNT];
>>> +    int ref_adc_val[3];
>>> +    int act_adc_val[3];
>>> +    int slope[2];
>>> +    int coeff[2];
>>> +};
>>> +
>>> +int two_cmp(int tmp, int mask)
>>> +{
>>> +    tmp = ~(tmp);
>>> +    tmp &= mask;
>>> +    tmp += 1;
>>> +
>>> +    /* Return negative value */
>>> +    return (0 - tmp);
>>> +}
>>> +
>>> +static unsigned int vtm_get_best_value(unsigned int s0, unsigned int
>>> s1,
>>> +                       unsigned int s2)
>>> +{
>>> +    int d01 = abs(s0 - s1);
>>> +    int d02 = abs(s0 - s2);
>>> +    int d12 = abs(s1 - s2);
>>> +
>>> +    if (d01 <= d02 && d01 <= d12)
>>> +        return (s0 + s1) / 2;
>>> +
>>> +    if (d02 <= d01 && d02 <= d12)
>>> +        return (s0 + s2) / 2;
>>> +
>>> +    return (s1 + s2) / 2;
>>> +}
>>> +
>>> +static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
>>> +                   int *temp)
>>> +{
>>> +    struct k3_j72xx_bandgap *bgp;
>>> +    unsigned int dtemp, s0, s1, s2;
>>> +
>>> +    bgp = devdata->bgp;
>>> +    /*
>>> +     * Errata is applicable for am654 pg 1.0 silicon/J7ES. There
>>> +     * is a variation of the order for certain degree centigrade on
>>> AM654.
>>> +     * Work around that by getting the average of two closest
>>> +     * readings out of three readings everytime we want to
>>> +     * report temperatures.
>>> +     *
>>> +     * Errata workaround.
>>> +     */
>>> +    s0 = readl(bgp->base + devdata->stat_offset) &
>>> +        K3_VTM_TS_STAT_DTEMP_MASK;
>>> +    s1 = readl(bgp->base + devdata->stat_offset) &
>>> +        K3_VTM_TS_STAT_DTEMP_MASK;
>>> +    s2 = readl(bgp->base + devdata->stat_offset) &
>>> +        K3_VTM_TS_STAT_DTEMP_MASK;
>>> +    dtemp = vtm_get_best_value(s0, s1, s2);
>>> +
>>> +    if (dtemp < 0 || dtemp > 1023)
>>> +        return -EINVAL;
>>> +
>>> +    *temp = derived_array[dtemp];
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +/* Get temperature callback function for thermal zone */
>>> +static int k3_thermal_get_temp(void *devdata, int *temp)
>>> +{
>>> +    struct k3_thermal_data *data = devdata;
>>> +    int ret = 0;
>>> +
>>> +    ret = k3_bgp_read_temp(data, temp);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    data->prev_temp = *temp;
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static const struct thermal_zone_of_device_ops k3_of_thermal_ops = {
>>> +    .get_temp = k3_thermal_get_temp,
>>> +};
>>> +
>>> +static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
>>> +{
>>> +    int low = 0, high = 1023, mid;
>>> +
>>> +    if (temp > 160000 || temp < -50000)
>>> +        return -EINVAL;
>>> +
>>> +    /* Binary search to find the adc code */
>>> +    while (low < (high - 1)) {
>>> +        mid = (low + high) / 2;
>>> +        if (temp <= derived_array[mid])
>>> +            high = mid;
>>> +        else
>>> +            low = mid;
>>> +    }
>>> +
>>> +    return mid;
>>> +}
>>> +
>>> +static void get_efuse_values(int id, struct k3_thermal_data *data,
>>> int *err,
>>> +                 struct k3_j72xx_bandgap *bgp)
>>> +{
>>> +    int i, tmp, pow;
>>> +
>>> +    /* Populate efuse reg offsets & Bit masks for -40C, 30C, 125C */
>>> +    switch (id) {
>>> +    case 0:
>>> +        data->ct_offsets[0] = 0x0;
>>> +        data->ct_offsets[1] = 0x8;
>>> +        data->ct_offsets[2] = 0x4;
>>> +        data->ct_bm[0] = 0x3f;
>>> +        data->ct_bm[1] = 0x1fe000;
>>> +        data->ct_bm[2] = 0x1ff;
>>> +        break;
>>> +
>>> +    case 1:
>>> +        data->ct_offsets[0] = 0x0;
>>> +        data->ct_offsets[1] = 0x8;
>>> +        data->ct_offsets[2] = 0x4;
>>> +        data->ct_bm[0] = 0xfc0;
>>> +        data->ct_bm[1] = 0x1fe00000;
>>> +        data->ct_bm[2] = 0x3fe00;
>>> +        break;
>>> +
>>> +    case 2:
>>> +        data->ct_offsets[0] = 0x0;
>>> +        data->ct_offsets[1] = -1;
>>> +        data->ct_offsets[2] = 0x4;
>>> +        data->ct_bm[0] = 0x3f000;
>>> +        data->ct_bm[1] = 0x7f800000;
>>> +        data->ct_bm[2] = 0x7fc0000;
>>> +        break;
>>> +
>>> +    case 3:
>>> +        data->ct_offsets[0] = 0x0;
>>> +        data->ct_offsets[1] = 0xC;
>>> +        data->ct_offsets[2] = -1; /* Spread across 2 registers */
>>> +        data->ct_bm[0] = 0xfc0000;
>>> +        data->ct_bm[1] = 0x1fe0;
>>> +        data->ct_bm[2] = 0x1f800000;
>>> +        break;
>>> +
>>> +    case 4:
>>> +        data->ct_offsets[0] = 0x0;
>>> +        data->ct_offsets[1] = 0xc;
>>> +        data->ct_offsets[2] = 0x8;
>>> +        data->ct_bm[0] = 0x3f000000;
>>> +        data->ct_bm[1] = 0x1fe000;
>>> +        data->ct_bm[2] = 0x1ff0;
>>> +        break;
>>> +    }
>>> +
>>> +    for (i = 0; i < 3; i++) {
>>> +        /* Extract the offset value using bit-mask */
>>> +        if (data->ct_offsets[i] == -1 && i == 1) {
>>> +            /* 25C offset Case of Sensor 2 split between 2 regs */
>>> +            tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29);
>>> +            tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3);
>>> +            pow = tmp & 0x80;
>>> +        } else if (data->ct_offsets[i] == -1 && i == 2) {
>>> +            /* 125C Case of Sensor 3 split between 2 regs */
>>> +            tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27);
>>> +            tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5);
>>> +            pow = tmp & 0x100;
>>> +        } else {
>>> +            tmp = readl(bgp->fuse_base + data->ct_offsets[i]);
>>> +            tmp &= data->ct_bm[i];
>>> +            tmp = tmp >> __ffs(data->ct_bm[i]);
>>> +
>>> +            /* Obtain the sign bit pow*/
>>> +            pow = data->ct_bm[i] >> __ffs(data->ct_bm[i]);
>>> +            pow += 1;
>>> +            pow /= 2;
>>> +        }
>>> +
>>> +        /* Check for negative value */
>>> +        if (tmp & pow) {
>>> +            /* 2's complement value */
>>> +            tmp = two_cmp(tmp, data->ct_bm[i] >>
>>> __ffs(data->ct_bm[i]));
>>> +        }
>>> +        err[i] = tmp;
>>> +    }
>>> +}
>>> +
>>> +#ifdef DEBUG_VTM
>>> +static void print_look_up_table(struct device *dev)
>>> +{
>>> +    int i;
>>> +
>>> +    dev_info(dev, "The contents of derived array\n");
>>> +    dev_info(dev, "Code   Temperaturei\n");
>>> +    for (i = 0; i <= 1023; i++)
>>> +        dev_info(dev, "%d       %d\n", i, derived_array[i]);
>>> +}
>>> +#endif
>>> +
>>> +static const struct of_device_id of_k3_j72xx_bandgap_match[];
>>> +
>>> +struct k3_j72xx_bandgap_j72xx_data {
>>> +    unsigned int    workaround;
>>> +};
>>> +
>>> +static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
>>> +{
>>> +    int ret = 0, cnt, val, id, reg_cnt = 0, j;
>>> +    int err[3], high_max, low_max;
>>> +    struct resource *res;
>>> +    struct device *dev = &pdev->dev;
>>> +    struct k3_j72xx_bandgap *bgp;
>>> +    struct k3_thermal_data *data;
>>> +    int workaround_needed = 0;
>>> +    const struct of_device_id *of_id;
>>> +    const struct k3_j72xx_bandgap_j72xx_data *driver_data;
>>> +
>>> +    bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
>>> +    if (!bgp)
>>> +        return -ENOMEM;
>>> +
>>> +    bgp->dev = dev;
>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +    bgp->base = devm_ioremap_resource(dev, res);
>>> +    if (IS_ERR(bgp->base))
>>> +        return PTR_ERR(bgp->base);
>>> +
>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>>> +    bgp->cfg2_base = devm_ioremap_resource(dev, res);
>>> +    if (IS_ERR(bgp->cfg2_base))
>>> +        return PTR_ERR(bgp->cfg2_base);
>>> +
>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>>> +    bgp->fuse_base = devm_ioremap_resource(dev, res);
>>> +    if (IS_ERR(bgp->fuse_base))
>>> +        return PTR_ERR(bgp->fuse_base);
>>> +
>>> +    of_id = of_match_device(of_k3_j72xx_bandgap_match, &pdev->dev);
>>> +    if (of_id) {
>>> +        driver_data = of_id->data;
>>> +        workaround_needed = driver_data->workaround;
>>> +    }
>>> +
>>> +    pm_runtime_enable(dev);
>>> +    ret = pm_runtime_get_sync(dev);
>>> +    if (ret < 0) {
>>> +        pm_runtime_put_noidle(dev);
>>> +        pm_runtime_disable(dev);
>>> +        return ret;
>>> +    }
>>> +
>>> +    /* Get the sensor count in the VTM */
>>> +    val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
>>> +    cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
>>> +    cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
>>> +    bgp->ts_cnt = cnt;
>>> +
>>> +    data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
>>> +    if (!data) {
>>> +        ret = -ENOMEM;
>>> +        goto err_alloc;
>>> +    }
>>> +
>>> +    /* Workaround not needed if bit30/bit31 is set even for J721e */
>>> +    if (workaround_needed && (readl(bgp->fuse_base + 0x0) &
>>> 0xc0000000) == 0xc0000000) {
>>> +        dev_info(bgp->dev, "work around NOT needed!!\n");
>>> +        workaround_needed = 0;
>>> +    }
>>> +
>>> +    /* Register the thermal sensors */
>>> +    for (id = 0; id < cnt; id++) {
>>> +        data[id].sensor_id = id;
>>> +        data[id].bgp = bgp;
>>> +        data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
>>> +        data[id].stat_offset = data[id].ctrl_offset +
>>> +                    K3_VTM_TMPSENS_STAT_OFFSET;
>>> +
>>> +        if (!workaround_needed)
>>> +            goto prepare_lookup;
>>> +        /* ref adc values for -40C, 30C & 125C respectively */
>>> +        data[id].ref_adc_val[0] = MINUS40CREF;
>>> +        data[id].ref_adc_val[1] = PLUS30CREF;
>>> +        data[id].ref_adc_val[2] = PLUS125CREF;
>>> +        get_efuse_values(id, &data[id], err, bgp);
>>> +
>>> +prepare_lookup:
>>> +        if (id == 0 && workaround_needed) {
>>> +            prep_lookup_table(err[0], err[1], err[2], 0);
>>> +        } else if (id == 0 && !workaround_needed) {
>>> +            for (j = 0; j < (sizeof(pvt_poly_golden) / 4); j++)
>>> +                derived_array[j] = pvt_poly_golden[j];
>>> +        }
>>> +
>>> +        val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
>>> +        val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
>>> +            K3_VTM_TMPSENS_CTRL_SOC |
>>> +            K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
>>> +        writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
>>> +
>>> +        bgp->ts_data[id] = &data[id];
>>> +        data[id].ti_thermal =
>>> +        devm_thermal_zone_of_sensor_register(bgp->dev, id,
>>> +                             &data[id],
>>> +                             &k3_of_thermal_ops);
>>> +        if (IS_ERR(data[id].ti_thermal)) {
>>> +            dev_err(bgp->dev, "thermal zone device is NULL\n");
>>> +            ret = PTR_ERR(data[id].ti_thermal);
>>> +            goto err_alloc;
>>> +        }
>>> +
>>> +        reg_cnt++;
>>> +
>>> +        /* Initialize Previous temp */
>>> +        k3_thermal_get_temp(&data[id], &data[id].prev_temp);
>>> +    }
>>> +
>>> +    /*
>>> +     * Program TSHUT thresholds
>>> +     * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
>>> +     * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN  bit
>>> +     *         This is already taken care as per of init
>>> +     * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN  bit
>>> +     */
>>> +    high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
>>> +    low_max = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
>>> +
>>> +    writel((low_max << 16) | high_max, data[0].bgp->cfg2_base +
>>> +           K3_VTM_MISC_CTRL2_OFFSET);
>>> +    mdelay(100);
>>> +    writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
>>> +           K3_VTM_MISC_CTRL_OFFSET);
>>> +
>>> +    platform_set_drvdata(pdev, bgp);
>>> +
>>> +#ifdef DEBUG_VTM
>>> +    print_look_up_table(dev);
>>> +#endif
>>> +    return 0;
>>> +
>>> +err_alloc:
>>> +    pm_runtime_put_sync(&pdev->dev);
>>> +    pm_runtime_disable(&pdev->dev);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
>>> +{
>>> +    pm_runtime_put_sync(&pdev->dev);
>>> +    pm_runtime_disable(&pdev->dev);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j721e_data
>>> = {
>>> +    .workaround = 1,
>>> +};
>>> +
>>> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j7200_data
>>> = {
>>> +    .workaround = 0,
>>> +};
>>> +
>>> +static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
>>> +    {
>>> +        .compatible = "ti,j721e-vtm",
>>> +        .data = (void *)&k3_j72xx_bandgap_j721e_data,
>>> +    },
>>> +    {
>>> +        .compatible = "ti,j7200-vtm",
>>> +        .data = (void *)&k3_j72xx_bandgap_j7200_data,
>>> +    },
>>> +    { /* sentinel */ },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
>>> +
>>> +static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
>>> +    .probe = k3_j72xx_bandgap_probe,
>>> +    .remove = k3_j72xx_bandgap_remove,
>>> +    .driver = {
>>> +        .name = "k3-j72xx-soc-thermal",
>>> +        .of_match_table    = of_k3_j72xx_bandgap_match,
>>> +    },
>>> +};
>>> +
>>> +module_platform_driver(k3_j72xx_bandgap_sensor_driver);
>>> +
>>> +MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_AUTHOR("J Keerthy <[e-mail]>");
>>>
>>
>>

J, KEERTHY Oct. 20, 2021, 2:05 p.m. UTC | #4

On 10/20/2021 2:38 AM, Daniel Lezcano wrote:
> On 19/10/2021 20:17, J, KEERTHY wrote:
>>
>>
>> On 10/19/2021 11:33 PM, Daniel Lezcano wrote:
>>>
>>> Hi Keerthy,
>>>
>>>
>>> On 19/10/2021 18:06, Keerthy wrote:
>>>> Add VTM thermal support. In the Voltage Thermal Management
>>>> Module(VTM), K3 J72XX supplies a voltage reference and a temperature
>>>> sensor feature that are gathered in the band gap voltage and
>>>> temperature sensor (VBGAPTS) module. The band gap provides current and
>>>> voltage reference for its internal circuits and other analog IP
>>>> blocks. The analog-to-digital converter (ADC) produces an output value
>>>> that is proportional to the silicon temperature.
>>>>
>>>> Currently reading temperatures only is supported.  There are no
>>>> active/passive cooling agent supported.
>>>>
>>>> J721e SoCs have errata i2128: https://www.ti.com/lit/pdf/sprz455
>>>>
>>>> The VTM Temperature Monitors (TEMPSENSORs) are trimmed during
>>>> production,
>>>> with the resulting values stored in software-readable registers.
>>>> Software
>>>> should use these  register values when translating the Temperature
>>>> Monitor output codes to temperature values.
>>>>
>>>> It has an involved workaround. Software needs to read the error codes
>>>> for
>>>> -40C, 30C, 125C from the efuse for each device & derive a new look up
>>>> table
>>>> for adc to temperature conversion. Involved calculating slopes &
>>>> constants
>>>> using 3 different straight line equations with adc refernce codes as the
>>>> y-axis & error codes in the x-axis.
>>>>
>>>> -40C to 30C
>>>> 30C to 125C
>>>> 125C to 150C
>>>>
>>>> With the above 2 line equations we derive the full look-up table to
>>>> workaround the errata i2128 for j721e SoC.
>>>>
>>>> Tested temperature reading on J721e SoC & J7200 SoC.
>>>
>>> I take some the time to trace the values in the array below and it
>>> results in a very nice curve, almost flat.
>>>
>>> That make me think the values are generated from a polynomial equation
>>> like the other driver.
>>>
>>> So instead of adding a full blob of array here which are 8KB in total in
>>> this file, why not generate the array dynamically at probe time ?
>>
>> Daniel,
>>
>> First of all thanks for the quick feedback!
>>
>> Warning: The below document is 200 odd MB document :-)
>>
>> TRM: http://www.ti.com/lit/pdf/spruil1
>>
>> Page: 2364
>>
>> y = a4 × x4 + a3 × x3 + a2 × x2 + a1 × x + a0
>>
>> Temperature = f(Code) °C
>>
>> a4 = -9.2627E-12
>> a3 = 6.0373E-08
>> a2 = -1.7058E-04
>> a1 = 3.2512E-01
>> a0 = -4.9002E+01
>>
>> I really do not want to implement that function in the driver. Hope you
>> agree with me.
> 
> s64 integer:
> 
> a4=-92627
> a3=603730000
> a2=-1705800000000
> a1=3251200000000000
> a0=-490019999999999936
> 
> AFAICT, the result with the program below gives the same values than the
> ones in the table. So far it is possible.
> 
>> Similarly we have the other table having a different polynomial.
>>
>> I used python to compute the tables from the equations.
> 
> Here is a C program to convert from floating point, to integer
> polynomial equation. Just multiply all factors by the same value which
> makes the smaller factor an integer.
> 
> Here it is -9.2627 x 10e-12
> 
> So it has to be multiplied by 10e12 => -9.2627, then 10e4 => -92627, so
> the factors need to be multiplied by 10e16
> The result of the equation needs then divided by 10e16 again. But as we
> want mC°, that will 10e13 instead.
> 
> Small program does:
> 
> myequation <index>
> 
> For example:
> 
> myequation 500
> 
> 77.880706
> 77880
> my integer factors:
> a4=-92627
> a3=603730000
> a2=-1705800000000
> a1=3251200000000000
> a0=-490019999999999936
> 
> 
> #include <math.h>
> #include <stdio.h>
> #include <stdlib.h>
> 
> /*
> 
> 
> 
>   * power-of kernel function
> 
> 
> 
>   */
> unsigned long long int_pow(unsigned long long base, unsigned int exp)
> {
>          unsigned long long result = 1;
> 
>          while (exp) {
>                  if (exp & 1)
>                          result *= base;
>                  exp >>= 1;
>                  base *= base;
>          }
> 
>          return result;
> }
> 
> int main(int argc, char *argv[])
> {
>          double x, y;
> 
>          double a4 = -9.2627 * pow(10, -12);
>          double a3 = 6.0373 * pow(10, -8);
>          double a2 = -1.7058 * pow(10, -4);
>          double a1 = 3.2512 * pow(10, -1);
>          double a0 = -4.9002 * 10;
> 
>          long long X, Y;
> 
> 	/*
> 	 * Put at the power-of in order to have the smaller factor to be
> 	 * an integer. For a4 we have to elevate at the power of 16.
> 	 */
>          long long A4 = a4 * int_pow(10, 16);
>          long long A3 = a3 * int_pow(10, 16);
>          long long A2 = a2 * int_pow(10, 16);
>          long long A1 = a1 * int_pow(10, 16);
>          long long A0 = a0 * int_pow(10, 16);
> 
>          if (argc < 2) {
>                  fprintf(stderr, "%s <index>\n", argv[0]);
>                  return 1;
>          }
> 
>          x = atof(argv[1]);
>          y = a4 * pow(x, 4) + a3 * pow(x, 3) + a2 * x * x + a1 * x + a0;
> 
>          printf("%f\n", y);
> 
>          X = atoi(argv[1]);
>          Y = A4 * int_pow(X, 4) + A3 * int_pow(X, 3) + A2 * int_pow(X, 2)
> + A1 * X + A0;
> 
> 	/*
> 	 * The polynomial equation returns the value in degree with a
> 	 * floating point. The thermal framework deals with mC°, so
> 	 * divide by the power of 13 instead of 16.
> 	 */
>          printf("%lld\n", Y / (long long)int_pow(10, 13));
> 
>          printf("my integer
> factors:\na4=%lld\na3=%lld\na2=%lld\na1=%lld\na0=%lld\n",
>                 A4, A3, A2, A1, A0);
> 
>          return 0;
> }
> 
> Logically, a simple function could be:
> 
> s64 myfactors[] = {
> 	-490019999999999936,
> 	3251200000000000,
> 	-1705800000000,
> 	603730000,
> 	-92627
> };
> 
> int myvalue(int index, s64 *factors, int nr_factors, int reduction)
> {
> 	s64 value = 0;
> 	int i;
> 	for (i = 0; i < nr_factors; i++) {
> 		value += factors[i] * int_pow(index, i);
> 
> 	return (int)(value / int_pow(10, reduction));
> }
> 
> void init_mytable(void)
> {
> 	int *mytable;
> 	const int size = 1024;
> 	int i;
> 
> 	mytable = kzalloc(sizeof(*mytable) * size);
> 
> 	for (i = 0; i < size; i++) {
> 		mytable[i] = myvalue(i, myfactors,
> 				ARRAY_SIZE(myfactors), 13);
> 	}
> }
> 
> What do you think ?

Wow! I will try them out in my driver & get back to you. Thanks for the 
effort.

Best Regards,
Keerthy

> 
>>> That will save space on disk and memory.
>>>
>>>
>>>
>>>> Signed-off-by: Keerthy <[e-mail]>
>>>> ---
>>>>    drivers/thermal/Makefile           |   2 +-
>>>>    drivers/thermal/k3_j72xx_bandgap.c | 772 +++++++++++++++++++++++++++++
>>>>    2 files changed, 773 insertions(+), 1 deletion(-)
>>>>    create mode 100644 drivers/thermal/k3_j72xx_bandgap.c
>>>>
>>>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>>>> index 82fc3e616e54..6dcaf2028ddc 100644
>>>> --- a/drivers/thermal/Makefile
>>>> +++ b/drivers/thermal/Makefile
>>>> @@ -28,7 +28,7 @@ thermal_sys-$(CONFIG_CPU_IDLE_THERMAL)    +=
>>>> cpuidle_cooling.o
>>>>    # devfreq cooling
>>>>    thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
>>>>    -obj-$(CONFIG_K3_THERMAL)    += k3_bandgap.o
>>>> +obj-$(CONFIG_K3_THERMAL)    += k3_bandgap.o k3_j72xx_bandgap.o
>>>>    # platform thermal drivers
>>>>    obj-y                += broadcom/
>>>>    obj-$(CONFIG_THERMAL_MMIO)        += thermal_mmio.o
>>>> diff --git a/drivers/thermal/k3_j72xx_bandgap.c
>>>> b/drivers/thermal/k3_j72xx_bandgap.c
>>>> new file mode 100644
>>>> index 000000000000..1aa048221291
>>>> --- /dev/null
>>>> +++ b/drivers/thermal/k3_j72xx_bandgap.c
>>>> @@ -0,0 +1,772 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * TI Bandgap temperature sensor driver for J72XX SoC Family
>>>> + *
>>>> + * Copyright (C) 2021 Texas Instruments Incorporated -
>>>> http://www.ti.com/
>>>> + */
>>>> +
>>>> +#include <linux/module.h>
>>>> +#include <linux/init.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/pm_runtime.h>
>>>> +#include <linux/err.h>
>>>> +#include <linux/types.h>
>>>> +#include <linux/spinlock.h>
>>>> +#include <linux/of_platform.h>
>>>> +#include <linux/io.h>
>>>> +#include <linux/thermal.h>
>>>> +#include <linux/of.h>
>>>> +#include <linux/delay.h>
>>>> +
>>>> +#define K3_VTM_DEVINFO_PWR0_OFFSET        0x4
>>>> +#define K3_VTM_DEVINFO_PWR0_CVD_CT_MASK        0xf
>>>> +#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK    0xf0
>>>> +#define K3_VTM_TMPSENS0_CTRL_OFFSET        0x300
>>>> +#define K3_VTM_MISC_CTRL_OFFSET            0xc
>>>> +#define K3_VTM_TMPSENS_STAT_OFFSET        0x8
>>>> +#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN        0x1
>>>> +#define K3_VTM_MISC_CTRL2_OFFSET        0x10
>>>> +#define K3_VTM_REGS_PER_TS            0x10
>>>> +#define K3_VTM_TS_STAT_DTEMP_MASK        0x3ff
>>>> +#define K3_VTM_MAX_NUM_TS            8
>>>> +#define K3_VTM_TMPSENS_CTRL_CBIASSEL        BIT(0)
>>>> +#define K3_VTM_TMPSENS_CTRL_SOC            BIT(5)
>>>> +#define K3_VTM_TMPSENS_CTRL_CLRZ        BIT(6)
>>>> +#define K3_VTM_TMPSENS_CTRL_CLKON_REQ        BIT(7)
>>>> +#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN    BIT(11)
>>>> +
>>>> +#define K3_VTM_CORRECTION_TEMP_CNT        3
>>>> +
>>>> +#define K3_VTM_ADC_BEGIN_VAL            6
>>>> +#define K3_VTM_ADC_END_VAL            944
>>>> +
>>>> +#define MINUS40CREF                5
>>>> +#define PLUS30CREF                253
>>>> +#define PLUS125CREF                730
>>>> +#define PLUS150CREF                940
>>>> +
>>>> +#define MAX_TEMP                123000
>>>> +#define COOL_DOWN_TEMP                105000
>>>> +
>>>> +//#define DEBUG_VTM
>>>> +
>>>> +static int derived_array[1024];
>>>> +
>>>> +/* Reference Look up table when work around is NOT needed */
>>>> +static const int pvt_poly_golden[] = {
>>>> +    -49002, -48677, -48352, -48028, -47704, -47381, -47057, -46734,
>>>> -46412,
>>>> +    -46090, -45768, -45446, -45125, -44804, -44484, -44163, -43844,
>>>> -43524,
>>>> +    -43205, -42886, -42567, -42249, -41931, -41614, -41297, -40980,
>>>> -40663,
>>>> +    -40347, -40031, -39716, -39400, -39085, -38771, -38457, -38143,
>>>> -37829,
>>>> +    -37516, -37203, -36890, -36578, -36266, -35955, -35643, -35332,
>>>> -35022,
>>>> +    -34712, -34402, -34092, -33783, -33474, -33165, -32857, -32549,
>>>> -32241,
>>>> +    -31934, -31626, -31320, -31013, -30707, -30401, -30096, -29791,
>>>> -29486,
>>>> +    -29182, -28877, -28573, -28270, -27967, -27664, -27361, -27059,
>>>> -26757,
>>>> +    -26455, -26154, -25853, -25552, -25252, -24952, -24652, -24353,
>>>> -24054,
>>>> +    -23755, -23456, -23158, -22860, -22563, -22265, -21968, -21672,
>>>> -21376,
>>>> +    -21079, -20784, -20488, -20193, -19899, -19604, -19310, -19016,
>>>> -18723,
>>>> +    -18429, -18136, -17844, -17551, -17259, -16968, -16676, -16385,
>>>> -16094,
>>>> +    -15804, -15514, -15224, -14934, -14645, -14356, -14067, -13779,
>>>> -13491,
>>>> +    -13203, -12916, -12628, -12342, -12055, -11769, -11483, -11197,
>>>> -10912,
>>>> +    -10627, -10342, -10057, -9773, -9489, -9206, -8922, -8639,
>>>> -8357, -8074,
>>>> +    -7792, -7510, -7229, -6947, -6666, -6386, -6105, -5825, -5546,
>>>> -5266,
>>>> +    -4987, -4708, -4429, -4151, -3873, -3595, -3318, -3041, -2764,
>>>> -2487,
>>>> +    -2211, -1935, -1659, -1384, -1108, -834, -559, -285, -11, 263,
>>>> 537, 810,
>>>> +    1083, 1355, 1628, 1900, 2171, 2443, 2714, 2985, 3255, 3526,
>>>> 3796, 4066,
>>>> +    4335, 4604, 4873, 5142, 5410, 5679, 5946, 6214, 6481, 6748,
>>>> 7015, 7281,
>>>> +    7548, 7813, 8079, 8344, 8609, 8874, 9139, 9403, 9667, 9931, 10194,
>>>> +    10457, 10720, 10983, 11245, 11507, 11769, 12030, 12292, 12553,
>>>> 12813,
>>>> +    13074, 13334, 13594, 13854, 14113, 14372, 14631, 14889, 15148,
>>>> 15406,
>>>> +    15664, 15921, 16178, 16435, 16692, 16948, 17205, 17461, 17716,
>>>> 17972,
>>>> +    18227, 18482, 18736, 18991, 19245, 19498, 19752, 20005, 20258,
>>>> 20511,
>>>> +    20764, 21016, 21268, 21520, 21771, 22022, 22273, 22524, 22774,
>>>> 23025,
>>>> +    23274, 23524, 23774, 24023, 24272, 24520, 24769, 25017, 25265,
>>>> 25512,
>>>> +    25760, 26007, 26254, 26500, 26747, 26993, 27239, 27484, 27730,
>>>> 27975,
>>>> +    28220, 28464, 28708, 28953, 29196, 29440, 29683, 29927, 30169,
>>>> 30412,
>>>> +    30654, 30896, 31138, 31380, 31621, 31862, 32103, 32344, 32584,
>>>> 32824,
>>>> +    33064, 33304, 33543, 33783, 34022, 34260, 34499, 34737, 34975,
>>>> 35213,
>>>> +    35450, 35687, 35924, 36161, 36397, 36634, 36870, 37105, 37341,
>>>> 37576,
>>>> +    37811, 38046, 38281, 38515, 38749, 38983, 39217, 39450, 39683,
>>>> 39916,
>>>> +    40149, 40381, 40614, 40846, 41077, 41309, 41540, 41771, 42002,
>>>> 42233,
>>>> +    42463, 42693, 42923, 43153, 43382, 43611, 43840, 44069, 44297,
>>>> 44526,
>>>> +    44754, 44981, 45209, 45436, 45663, 45890, 46117, 46343, 46570,
>>>> 46796,
>>>> +    47021, 47247, 47472, 47697, 47922, 48147, 48371, 48595, 48819,
>>>> 49043,
>>>> +    49266, 49490, 49713, 49935, 50158, 50380, 50603, 50824, 51046,
>>>> 51268,
>>>> +    51489, 51710, 51931, 52151, 52372, 52592, 52812, 53031, 53251,
>>>> 53470,
>>>> +    53689, 53908, 54127, 54345, 54563, 54781, 54999, 55217, 55434,
>>>> 55651,
>>>> +    55868, 56085, 56301, 56517, 56733, 56949, 57165, 57380, 57595,
>>>> 57810,
>>>> +    58025, 58239, 58454, 58668, 58882, 59095, 59309, 59522, 59735,
>>>> 59948,
>>>> +    60160, 60373, 60585, 60797, 61009, 61220, 61432, 61643, 61854,
>>>> 62064,
>>>> +    62275, 62485, 62695, 62905, 63115, 63324, 63534, 63743, 63952,
>>>> 64160,
>>>> +    64369, 64577, 64785, 64993, 65200, 65408, 65615, 65822, 66029,
>>>> 66236,
>>>> +    66442, 66648, 66854, 67060, 67266, 67471, 67676, 67881, 68086,
>>>> 68291,
>>>> +    68495, 68699, 68903, 69107, 69311, 69514, 69717, 69920, 70123,
>>>> 70326,
>>>> +    70528, 70730, 70932, 71134, 71336, 71537, 71738, 71939, 72140,
>>>> 72341,
>>>> +    72541, 72742, 72942, 73142, 73341, 73541, 73740, 73939, 74138,
>>>> 74337,
>>>> +    74535, 74733, 74932, 75130, 75327, 75525, 75722, 75919, 76116,
>>>> 76313,
>>>> +    76510, 76706, 76902, 77098, 77294, 77490, 77685, 77881, 78076,
>>>> 78271,
>>>> +    78465, 78660, 78854, 79048, 79242, 79436, 79630, 79823, 80016,
>>>> 80210,
>>>> +    80402, 80595, 80788, 80980, 81172, 81364, 81556, 81747, 81939,
>>>> 82130,
>>>> +    82321, 82512, 82702, 82893, 83083, 83273, 83463, 83653, 83843,
>>>> 84032,
>>>> +    84221, 84410, 84599, 84788, 84976, 85165, 85353, 85541, 85728,
>>>> 85916,
>>>> +    86103, 86291, 86478, 86665, 86851, 87038, 87224, 87411, 87597,
>>>> 87782,
>>>> +    87968, 88154, 88339, 88524, 88709, 88894, 89078, 89263, 89447,
>>>> 89631,
>>>> +    89815, 89999, 90182, 90366, 90549, 90732, 90915, 91098, 91280,
>>>> 91463,
>>>> +    91645, 91827, 92009, 92191, 92372, 92554, 92735, 92916, 93097,
>>>> 93277,
>>>> +    93458, 93638, 93818, 93998, 94178, 94358, 94537, 94717, 94896,
>>>> 95075,
>>>> +    95254, 95433, 95611, 95790, 95968, 96146, 96324, 96501, 96679,
>>>> 96856,
>>>> +    97033, 97211, 97387, 97564, 97741, 97917, 98093, 98269, 98445,
>>>> 98621,
>>>> +    98797, 98972, 99147, 99322, 99497, 99672, 99847, 100021, 100196,
>>>> 100370,
>>>> +    100544, 100718, 100891, 101065, 101238, 101411, 101584, 101757,
>>>> 101930,
>>>> +    102103, 102275, 102447, 102619, 102791, 102963, 103135, 103306,
>>>> 103478,
>>>> +    103649, 103820, 103991, 104161, 104332, 104502, 104673, 104843,
>>>> 105013,
>>>> +    105182, 105352, 105522, 105691, 105860, 106029, 106198, 106367,
>>>> 106535,
>>>> +    106704, 106872, 107040, 107208, 107376, 107544, 107711, 107878,
>>>> 108046,
>>>> +    108213, 108380, 108546, 108713, 108880, 109046, 109212, 109378,
>>>> 109544,
>>>> +    109710, 109875, 110041, 110206, 110371, 110536, 110701, 110866,
>>>> 111030,
>>>> +    111195, 111359, 111523, 111687, 111851, 112015, 112178, 112342,
>>>> 112505,
>>>> +    112668, 112831, 112994, 113157, 113319, 113482, 113644, 113806,
>>>> 113968,
>>>> +    114130, 114292, 114453, 114615, 114776, 114937, 115098, 115259,
>>>> 115420,
>>>> +    115580, 115741, 115901, 116061, 116221, 116381, 116541, 116701,
>>>> 116860,
>>>> +    117019, 117179, 117338, 117497, 117655, 117814, 117973, 118131,
>>>> 118289,
>>>> +    118447, 118605, 118763, 118921, 119078, 119236, 119393, 119550,
>>>> 119707,
>>>> +    119864, 120021, 120178, 120334, 120490, 120647, 120803, 120959,
>>>> 121115,
>>>> +    121270, 121426, 121581, 121737, 121892, 122047, 122202, 122356,
>>>> 122511,
>>>> +    122666, 122820, 122974, 123128, 123282, 123436, 123590, 123744,
>>>> 123897,
>>>> +    124050, 124204, 124357, 124510, 124662, 124815, 124968, 125120,
>>>> 125273,
>>>> +    125425, 125577, 125729, 125881, 126032, 126184, 126335, 126487,
>>>> 126638,
>>>> +    126789, 126940, 127091, 127241, 127392, 127542, 127693, 127843,
>>>> 127993,
>>>> +    128143, 128293, 128442, 128592, 128741, 128891, 129040, 129189,
>>>> 129338,
>>>> +    129487, 129635, 129784, 129932, 130081, 130229, 130377, 130525,
>>>> 130673,
>>>> +    130821, 130968, 131116, 131263, 131410, 131558, 131705, 131851,
>>>> 131998,
>>>> +    132145, 132291, 132438, 132584, 132730, 132876, 133022, 133168,
>>>> 133314,
>>>> +    133460, 133605, 133750, 133896, 134041, 134186, 134331, 134476,
>>>> 134620,
>>>> +    134765, 134909, 135054, 135198, 135342, 135486, 135630, 135773,
>>>> 135917,
>>>> +    136061, 136204, 136347, 136491, 136634, 136777, 136919, 137062,
>>>> 137205,
>>>> +    137347, 137490, 137632, 137774, 137916, 138058, 138200, 138342,
>>>> 138483,
>>>> +    138625, 138766, 138907, 139049, 139190, 139331, 139471, 139612,
>>>> 139753,
>>>> +    139893, 140034, 140174, 140314, 140454, 140594, 140734, 140874,
>>>> 141013,
>>>> +    141153, 141292, 141432, 141571, 141710, 141849, 141988, 142127,
>>>> 142265,
>>>> +    142404, 142542, 142681, 142819, 142957, 143095, 143233, 143371,
>>>> 143509,
>>>> +    143646, 143784, 143921, 144058, 144196, 144333, 144470, 144607,
>>>> 144743,
>>>> +    144880, 145017, 145153, 145289, 145426, 145562, 145698, 145834,
>>>> 145970,
>>>> +    146105, 146241, 146377, 146512, 146647, 146783, 146918, 147053,
>>>> 147188,
>>>> +    147323, 147457, 147592, 147727, 147861, 147995, 148130, 148264,
>>>> 148398,
>>>> +    148532, 148666, 148799, 148933, 149067, 149200, 149333, 149467,
>>>> 149600,
>>>> +    149733, 149866, 149999, 150131, 150264, 150397, 150529, 150661,
>>>> 150794,
>>>> +    150926, 151058, 151190, 151322, 151454, 151585, 151717, 151848,
>>>> 151980,
>>>> +    152111,    152242, 152373, 152505, 152635, 152766, 152897,
>>>> 153028, 153158,
>>>> +    153289, 153419, 153549, 153680, 153810, 153940, 154070, 154199,
>>>> 154329,
>>>> +    154459, 154588, 154718, 154847, 154976, 155105, 155235, 155363,
>>>> 155492,
>>>> +    155621, 155750, 155879, 156007, 156135, 156264, 156392, 156520,
>>>> 156648,
>>>> +    156776, 156904, 157032, 157160, 157287, 157415, 157542, 157670,
>>>> 157797,
>>>> +    157924, 158051, 158178, 158305, 158432, 158559, 158685, 158812,
>>>> 158938,
>>>> +    159065, 159191, 159317, 159443, 159569,
>>>> +};
>>>> +
>>>> +/* Reference Look up table when work around is needed */
>>>> +static const int pvt_poly[] = {
>>>> +    -41523, -41210, -40898, -40586, -40274, -39963, -39651,
>>>> -39340,    -39029,
>>>> +    -38718, -38408, -38098, -37788, -37478, -37168, -36859, -36550,
>>>> -36241,
>>>> +    -35933, -35624, -35316, -35008, -34701, -34393, -34086, -33779,
>>>> -33472,
>>>> +    -33166, -32859, -32553, -32247, -31942, -31636, -31331, -31026,
>>>> -30722,
>>>> +    -30417, -30113, -29809, -29505, -29202, -28899, -28596, -28293,
>>>> -27990,
>>>> +    -27688, -27386, -27084, -26782, -26481, -26179, -25878, -25578,
>>>> -25277,
>>>> +    -24977, -24677, -24377, -24078, -23778, -23479, -23180, -22882,
>>>> -22583,
>>>> +    -22285, -21987, -21689, -21392, -21095, -20797, -20501, -20204,
>>>> -19908,
>>>> +    -19612, -19316, -19020, -18725, -18430, -18135, -17840, -17545,
>>>> -17251,
>>>> +    -16957, -16663, -16370, -16077, -15783, -15491, -15198,
>>>> -14906, -14613,
>>>> +    -14321, -14030, -13738, -13447, -13156, -12865, -12575, -12284,
>>>> -11994,
>>>> +    -11704, -11415, -11125, -10836, -10547, -10259, -9970, -9682,
>>>> -9394,
>>>> +    -9106, -8819, -8531, -8244, -7957, -7671, -7384, -7098, -6812,
>>>> -6527,
>>>> +    -6241, -5956, -5671, -5386, -5102, -4817, -4533, -4250, -3966,
>>>> -3683,
>>>> +    -3399, -3117, -2834, -2551, -2269, -1987, -1706, -1424, -1143,
>>>> -862,
>>>> +    -581, -300, -20, 260, 540, 820, 1099, 1378, 1657, 1936, 2215, 2493,
>>>> +    2771, 3049, 3326, 3604, 3881, 4158, 4434, 4711, 4987, 5263,
>>>> 5539, 5814,
>>>> +    6089, 6364, 6639, 6914, 7188, 7462, 7736, 8010, 8283, 8556,
>>>> 8829, 9102,
>>>> +    9374, 9647, 9919, 10191, 10462, 10733, 11005, 11275, 11546, 11816,
>>>> +    12087, 12357, 12626, 12896, 13165, 13434, 13703, 13971, 14240,
>>>> 14508,
>>>> +    14776, 15043, 15311, 15578, 15845, 16111, 16378, 16644, 16910,
>>>> 17176,
>>>> +    17441, 17707, 17972, 18237, 18501, 18766, 19030, 19294, 19557,
>>>> 19821,
>>>> +    20084, 20347, 20610, 20872, 21135, 21397, 21658, 21920, 22181,
>>>> 22443,
>>>> +    22703, 22964, 23225, 23485, 23745, 24005, 24264, 24523, 24782,
>>>> 25041,
>>>> +    25300, 25558, 25816, 26074, 26332, 26589, 26846, 27103, 27360,
>>>> 27617,
>>>> +    27873, 28129, 28385, 28640, 28896, 29151, 29406, 29660, 29915,
>>>> 30169,
>>>> +    30423, 30677, 30930, 31183, 31437, 31689, 31942, 32194, 32446,
>>>> 32698,
>>>> +    32950, 33201, 33452, 33703, 33954, 34205, 34455, 34705, 34955,
>>>> 35204,
>>>> +    35454, 35703, 35952, 36200, 36449, 36697, 36945, 37192, 37440,
>>>> 37687,
>>>> +    37934, 38181, 38427, 38674, 38920, 39166, 39411, 39657, 39902,
>>>> 40147,
>>>> +    40391, 40636, 40880, 41124, 41368, 41611, 41855, 42098, 42341,
>>>> 42583,
>>>> +    42826, 43068, 43310, 43551, 43793, 44034, 44275, 44516, 44756,
>>>> 44997,
>>>> +    45237, 45477, 45716, 45956, 46195, 46434, 46672, 46911, 47149,
>>>> 47387,
>>>> +    47625, 47862, 48100, 48337, 48573, 48810, 49046, 49282, 49518,
>>>> 49754,
>>>> +    49989, 50225, 50460, 50694, 50929, 51163, 51397, 51631, 51865,
>>>> 52098,
>>>> +    52331, 52564, 52797, 53029, 53261, 53493, 53725, 53956, 54188,
>>>> 54419,
>>>> +    54650, 54880, 55110, 55341, 55570, 55800, 56030, 56259, 56488,
>>>> 56716,
>>>> +    56945, 57173, 57401, 57629, 57856, 58084, 58311, 58538, 58764,
>>>> 58991,
>>>> +    59217, 59443, 59669, 59894, 60119, 60344, 60569, 60794, 61018,
>>>> 61242,
>>>> +    61466, 61690, 61913, 62136, 62359, 62582, 62804, 63026, 63249,
>>>> 63470,
>>>> +    63692, 63913, 64134, 64355, 64576, 64796, 65016, 65236, 65456,
>>>> 65675,
>>>> +    65894, 66113, 66332, 66551, 66769, 66987, 67205, 67423, 67640,
>>>> 67857,
>>>> +    68074, 68291, 68507, 68723, 68939, 69155, 69371, 69586, 69801,
>>>> 70016,
>>>> +    70230, 70445, 70659, 70873, 71086, 71300, 71513, 71726, 71939,
>>>> 72151,
>>>> +    72364, 72576, 72787, 72999, 73210, 73422, 73632, 73843, 74053,
>>>> 74264,
>>>> +    74474, 74683, 74893, 75102, 75311, 75520, 75729, 75937, 76145,
>>>> 76353,
>>>> +    76561, 76768, 76975, 77182, 77389, 77595, 77802, 78008, 78213,
>>>> 78419,
>>>> +    78624, 78829, 79034, 79239, 79443, 79647, 79851, 80055, 80259,
>>>> 80462,
>>>> +    80665, 80868, 81070, 81273, 81475, 81676, 81878, 82079, 82281,
>>>> 82482,
>>>> +    82682, 82883, 83083, 83283, 83483, 83682, 83882, 84081, 84280,
>>>> 84478,
>>>> +    84677, 84875, 85073, 85270, 85468, 85665, 85862, 86059, 86255,
>>>> 86452,
>>>> +    86648, 86844, 87039, 87234, 87430, 87625, 87819, 88014, 88208,
>>>> 88402,
>>>> +    88596, 88789, 88982, 89175, 89368, 89561, 89753, 89945, 90137,
>>>> 90329,
>>>> +    90520, 90712, 90903, 91093, 91284, 91474, 91664, 91854, 92044,
>>>> 92233,
>>>> +    92422, 92611, 92800, 92988, 93176, 93364, 93552, 93739, 93927,
>>>> 94114,
>>>> +    94301, 94487, 94673, 94860, 95045, 95231, 95417, 95602, 95787,
>>>> 95971,
>>>> +    96156, 96340, 96524, 96708, 96892, 97075, 97258, 97441, 97624,
>>>> 97806,
>>>> +    97988, 98170, 98352, 98533, 98714, 98895, 99076, 99257, 99437,
>>>> 99617,
>>>> +    99797, 99977, 100156, 100335, 100514, 100693, 100871, 101050,
>>>> 101228,
>>>> +    101405, 101583, 101760, 101937, 102114, 102291, 102467, 102643,
>>>> 102819,
>>>> +    102995, 103170, 103346, 103521, 103695, 103870, 104044, 104218,
>>>> 104392,
>>>> +    104566, 104739, 104912, 105085, 105258, 105430, 105603, 105775,
>>>> 105946,
>>>> +    106118, 106289, 106460, 106631, 106802, 106972, 107142, 107312,
>>>> 107482,
>>>> +    107651, 107820, 107989, 108158, 108327, 108495, 108663, 108831,
>>>> 108998,
>>>> +    109166, 109333, 109500, 109666, 109833, 109999, 110165, 110331,
>>>> 110496,
>>>> +    110661, 110827, 110991, 111156, 111320, 111484, 111648, 111812,
>>>> 111975,
>>>> +    112139, 112301, 112464, 112627, 112789, 112951, 113113, 113274,
>>>> 113436,
>>>> +    113597, 113758, 113918, 114079, 114239, 114399, 114559, 114718,
>>>> 114877,
>>>> +    115036, 115195, 115354, 115512, 115670, 115828, 115986, 116143,
>>>> 116300,
>>>> +    116457, 116614, 116770, 116926, 117082, 117238, 117394, 117549,
>>>> 117704,
>>>> +    117859, 118014, 118168, 118322, 118476, 118630, 118783, 118937,
>>>> 119090,
>>>> +    119242, 119395, 119547, 119699, 119851, 120003, 120154, 120305,
>>>> 120456,
>>>> +    120607, 120757, 120907, 121057, 121207, 121357, 121506, 121655,
>>>> 121804,
>>>> +    121953, 122101, 122249, 122397, 122545, 122692, 122839, 122986,
>>>> 123133,
>>>> +    123280, 123426, 123572, 123718, 123863, 124009, 124154, 124299,
>>>> 124443,
>>>> +    124588, 124732, 124876, 125020, 125163, 125306, 125449, 125592,
>>>> 125735,
>>>> +    125877, 126019, 126161, 126303, 126444, 126585, 126726, 126867,
>>>> 127008,
>>>> +    127148, 127288, 127428, 127567, 127707, 127846, 127985, 128123,
>>>> 128262,
>>>> +    128400, 128538, 128676, 128813, 128950, 129087, 129224, 129361,
>>>> 129497,
>>>> +    129633, 129769, 129905, 130040, 130175, 130310, 130445, 130579,
>>>> 130713,
>>>> +    130847, 130981, 131115, 131248, 131381, 131514, 131647, 131779,
>>>> 131911,
>>>> +    132043, 132175, 132306, 132438, 132569, 132699, 132830, 132960,
>>>> 133090,
>>>> +    133220, 133350, 133479, 133608, 133737, 133866, 133994, 134123,
>>>> 134251,
>>>> +    134378, 134506, 134633, 134760, 134887, 135014, 135140, 135266,
>>>> 135392,
>>>> +    135518, 135643, 135768, 135893, 136018, 136143, 136267, 136391,
>>>> 136515,
>>>> +    136638, 136762, 136885, 137008, 137130, 137253, 137375, 137497,
>>>> 137619,
>>>> +    137740, 137862, 137983, 138103, 138224, 138344, 138464, 138584,
>>>> 138704,
>>>> +    138823, 138943, 139062, 139180, 139299, 139417, 139535, 139653,
>>>> 139770,
>>>> +    139888, 140005, 140122, 140238, 140355, 140471, 140587, 140703,
>>>> 140818,
>>>> +    140933, 141048, 141163, 141278, 141392, 141506, 141620, 141734,
>>>> 141847,
>>>> +    141960, 142073, 142186, 142298, 142411, 142523, 142634, 142746,
>>>> 142857,
>>>> +    142968, 143079, 143190, 143300, 143410, 143520, 143630, 143740,
>>>> 143849,
>>>> +    143958, 144067, 144175, 144283, 144391, 144499, 144607, 144714,
>>>> 144821,
>>>> +    144928, 145035, 145142, 145248, 145354, 145459, 145565, 145670,
>>>> 145775,
>>>> +    145880, 145985, 146089, 146193, 146297, 146401, 146504, 146608,
>>>> 146711,
>>>> +    146813, 146916, 147018, 147120, 147222, 147324, 147425, 147526,
>>>> 147627,
>>>> +    147728, 147828, 147928, 148028, 148128, 148228, 148327, 148426,
>>>> 148525,
>>>> +    148623, 148722, 148820, 148918, 149015, 149113, 149210, 149307,
>>>> 149404,
>>>> +    149500, 149596, 149692, 149788, 149884, 149979, 150074, 150169,
>>>> 150264,
>>>> +    150358, 150452, 150546, 150640, 150733, 150827, 150920, 151013,
>>>> 151105,
>>>> +    151197, 151290, 151381, 151473, 151564, 151656, 151747, 151837,
>>>> 151928,
>>>> +    152018, 152108, 152198, 152287, 152377, 152466, 152555, 152643,
>>>> 152732,
>>>> +    152820, 152908, 152995, 153083, 153170, 153257, 153344, 153430,
>>>> 153517,
>>>> +    153603, 153689, 153774, 153860, 153945, 154030, 154114, 154199,
>>>> 154283,
>>>> +    154367, 154451, 154534, 154618, 154701, 154784, 154866, 154949,
>>>> 155031,
>>>> +    155113, 155194, 155276, 155357, 155438, 155519, 155599, 155680,
>>>> 155760,
>>>> +    155839, 155919, 155998, 156078, 156156, 156235, 156314, 156392,
>>>> 156470,
>>>> +    156547, 156625, 156702, 156779, 156856, 156933, 157009, 157085,
>>>> 157161,
>>>> +};
>>>> +
>>>> +static void fill_table(int err1, int err2, int ref1, int ref2, int
>>>> idx1,
>>>> +               int idx2)
>>>> +{
>>>> +    int m, c, num, den, i, err;
>>>> +
>>>> +    /**
>>>> +     * Calculate the slope with adc values read from the register
>>>> +     * as the y-axis param and err in adc value as x-axis param
>>>> +     */
>>>> +    if (err1 != err2) {
>>>> +        num = ref2 - ref1;
>>>> +        den = err2 - err1;
>>>> +        m = num / den;
>>>> +        c = ref2 - m * err2;
>>>> +        for (i = idx1; i <= idx2; i++) {
>>>> +            err = (i - c) / m;
>>>> +            if (((i + err1) < 0) || ((i + err1) > 1023))
>>>> +                continue;
>>>> +            derived_array[i] = pvt_poly[i + err];
>>>> +        }
>>>> +    } else { /* Constant error take care of divide by zero */
>>>> +        for (i = idx1; i < idx2; i++) {
>>>> +            if (((i + err1) < 0) || ((i + err1) > 1023))
>>>> +                continue;
>>>> +            derived_array[i] = pvt_poly[i + err1];
>>>> +        }
>>>> +    }
>>>> +}
>>>> +
>>>> +static int prep_lookup_table(int minus40cerr, int plus30cerr, int
>>>> plus125cerr,
>>>> +                 int plus150cerr)
>>>> +{
>>>> +    int start_temp, inc, i;
>>>> +
>>>> +    /* Fill up the lookup table region -40C to +30C */
>>>> +    fill_table(minus40cerr, plus30cerr, MINUS40CREF, PLUS30CREF, 0,
>>>> +           PLUS30CREF);
>>>> +    /* Fill up the lookup table region +30C to +125C */
>>>> +    fill_table(plus30cerr, plus125cerr, PLUS30CREF, PLUS125CREF,
>>>> PLUS30CREF,
>>>> +           PLUS125CREF);
>>>> +    /* Fill up the lookup table region +125C to +150C */
>>>> +    fill_table(plus125cerr, plus150cerr, PLUS125CREF, PLUS150CREF,
>>>> PLUS125CREF,
>>>> +           PLUS150CREF);
>>>> +
>>>> +    /* Get to the first valid temperature */
>>>> +    i = 0;
>>>> +    while (!derived_array[i])
>>>> +        i++;
>>>> +
>>>> +    start_temp = i;
>>>> +    /*
>>>> +     * Get to the last zero index and back fill the temperature for
>>>> +     * sake of continuity
>>>> +     */
>>>> +    if (i) {
>>>> +        /* 300 milli celsius steps */
>>>> +        while (i--)
>>>> +            derived_array[i] = derived_array[i + 1] - 300;
>>>> +        /* case 0 */
>>>> +        derived_array[i] = derived_array[i + 1] - 300;
>>>> +    }
>>>> +
>>>> +    /*
>>>> +     * Fill the last trailing 0s which are unfilled with increments of
>>>> +     * 100 milli celsius till 1023 code
>>>> +     */
>>>> +    i = 1023;
>>>> +    while (!derived_array[i])
>>>> +        i--;
>>>> +
>>>> +    i++;
>>>> +    inc = 1;
>>>> +    while (i < 1024) {
>>>> +        derived_array[i] = derived_array[i - 1] + inc * 100;
>>>> +        i++;
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +struct k3_thermal_data;
>>>> +
>>>> +struct k3_j72xx_bandgap {
>>>> +    struct device *dev;
>>>> +    void __iomem *base;
>>>> +    void __iomem *cfg2_base;
>>>> +    void __iomem *fuse_base;
>>>> +    const struct k3_j72xx_bandgap_data    *conf;
>>>> +    spinlock_t lock; /* shields this struct */
>>>> +    int ts_cnt;
>>>> +    struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
>>>> +};
>>>> +
>>>> +/* common data structures */
>>>> +struct k3_thermal_data {
>>>> +    struct thermal_zone_device *ti_thermal;
>>>> +    struct thermal_cooling_device *cool_dev;
>>>> +    struct k3_j72xx_bandgap *bgp;
>>>> +    enum thermal_device_mode mode;
>>>> +    int sensor_id;
>>>> +    u32 ctrl_offset;
>>>> +    u32 stat_offset;
>>>> +    int prev_temp;
>>>> +    int ct_offsets[K3_VTM_CORRECTION_TEMP_CNT];
>>>> +    int ct_bm[K3_VTM_CORRECTION_TEMP_CNT];
>>>> +    int ref_adc_val[3];
>>>> +    int act_adc_val[3];
>>>> +    int slope[2];
>>>> +    int coeff[2];
>>>> +};
>>>> +
>>>> +int two_cmp(int tmp, int mask)
>>>> +{
>>>> +    tmp = ~(tmp);
>>>> +    tmp &= mask;
>>>> +    tmp += 1;
>>>> +
>>>> +    /* Return negative value */
>>>> +    return (0 - tmp);
>>>> +}
>>>> +
>>>> +static unsigned int vtm_get_best_value(unsigned int s0, unsigned int
>>>> s1,
>>>> +                       unsigned int s2)
>>>> +{
>>>> +    int d01 = abs(s0 - s1);
>>>> +    int d02 = abs(s0 - s2);
>>>> +    int d12 = abs(s1 - s2);
>>>> +
>>>> +    if (d01 <= d02 && d01 <= d12)
>>>> +        return (s0 + s1) / 2;
>>>> +
>>>> +    if (d02 <= d01 && d02 <= d12)
>>>> +        return (s0 + s2) / 2;
>>>> +
>>>> +    return (s1 + s2) / 2;
>>>> +}
>>>> +
>>>> +static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
>>>> +                   int *temp)
>>>> +{
>>>> +    struct k3_j72xx_bandgap *bgp;
>>>> +    unsigned int dtemp, s0, s1, s2;
>>>> +
>>>> +    bgp = devdata->bgp;
>>>> +    /*
>>>> +     * Errata is applicable for am654 pg 1.0 silicon/J7ES. There
>>>> +     * is a variation of the order for certain degree centigrade on
>>>> AM654.
>>>> +     * Work around that by getting the average of two closest
>>>> +     * readings out of three readings everytime we want to
>>>> +     * report temperatures.
>>>> +     *
>>>> +     * Errata workaround.
>>>> +     */
>>>> +    s0 = readl(bgp->base + devdata->stat_offset) &
>>>> +        K3_VTM_TS_STAT_DTEMP_MASK;
>>>> +    s1 = readl(bgp->base + devdata->stat_offset) &
>>>> +        K3_VTM_TS_STAT_DTEMP_MASK;
>>>> +    s2 = readl(bgp->base + devdata->stat_offset) &
>>>> +        K3_VTM_TS_STAT_DTEMP_MASK;
>>>> +    dtemp = vtm_get_best_value(s0, s1, s2);
>>>> +
>>>> +    if (dtemp < 0 || dtemp > 1023)
>>>> +        return -EINVAL;
>>>> +
>>>> +    *temp = derived_array[dtemp];
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +/* Get temperature callback function for thermal zone */
>>>> +static int k3_thermal_get_temp(void *devdata, int *temp)
>>>> +{
>>>> +    struct k3_thermal_data *data = devdata;
>>>> +    int ret = 0;
>>>> +
>>>> +    ret = k3_bgp_read_temp(data, temp);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    data->prev_temp = *temp;
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static const struct thermal_zone_of_device_ops k3_of_thermal_ops = {
>>>> +    .get_temp = k3_thermal_get_temp,
>>>> +};
>>>> +
>>>> +static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
>>>> +{
>>>> +    int low = 0, high = 1023, mid;
>>>> +
>>>> +    if (temp > 160000 || temp < -50000)
>>>> +        return -EINVAL;
>>>> +
>>>> +    /* Binary search to find the adc code */
>>>> +    while (low < (high - 1)) {
>>>> +        mid = (low + high) / 2;
>>>> +        if (temp <= derived_array[mid])
>>>> +            high = mid;
>>>> +        else
>>>> +            low = mid;
>>>> +    }
>>>> +
>>>> +    return mid;
>>>> +}
>>>> +
>>>> +static void get_efuse_values(int id, struct k3_thermal_data *data,
>>>> int *err,
>>>> +                 struct k3_j72xx_bandgap *bgp)
>>>> +{
>>>> +    int i, tmp, pow;
>>>> +
>>>> +    /* Populate efuse reg offsets & Bit masks for -40C, 30C, 125C */
>>>> +    switch (id) {
>>>> +    case 0:
>>>> +        data->ct_offsets[0] = 0x0;
>>>> +        data->ct_offsets[1] = 0x8;
>>>> +        data->ct_offsets[2] = 0x4;
>>>> +        data->ct_bm[0] = 0x3f;
>>>> +        data->ct_bm[1] = 0x1fe000;
>>>> +        data->ct_bm[2] = 0x1ff;
>>>> +        break;
>>>> +
>>>> +    case 1:
>>>> +        data->ct_offsets[0] = 0x0;
>>>> +        data->ct_offsets[1] = 0x8;
>>>> +        data->ct_offsets[2] = 0x4;
>>>> +        data->ct_bm[0] = 0xfc0;
>>>> +        data->ct_bm[1] = 0x1fe00000;
>>>> +        data->ct_bm[2] = 0x3fe00;
>>>> +        break;
>>>> +
>>>> +    case 2:
>>>> +        data->ct_offsets[0] = 0x0;
>>>> +        data->ct_offsets[1] = -1;
>>>> +        data->ct_offsets[2] = 0x4;
>>>> +        data->ct_bm[0] = 0x3f000;
>>>> +        data->ct_bm[1] = 0x7f800000;
>>>> +        data->ct_bm[2] = 0x7fc0000;
>>>> +        break;
>>>> +
>>>> +    case 3:
>>>> +        data->ct_offsets[0] = 0x0;
>>>> +        data->ct_offsets[1] = 0xC;
>>>> +        data->ct_offsets[2] = -1; /* Spread across 2 registers */
>>>> +        data->ct_bm[0] = 0xfc0000;
>>>> +        data->ct_bm[1] = 0x1fe0;
>>>> +        data->ct_bm[2] = 0x1f800000;
>>>> +        break;
>>>> +
>>>> +    case 4:
>>>> +        data->ct_offsets[0] = 0x0;
>>>> +        data->ct_offsets[1] = 0xc;
>>>> +        data->ct_offsets[2] = 0x8;
>>>> +        data->ct_bm[0] = 0x3f000000;
>>>> +        data->ct_bm[1] = 0x1fe000;
>>>> +        data->ct_bm[2] = 0x1ff0;
>>>> +        break;
>>>> +    }
>>>> +
>>>> +    for (i = 0; i < 3; i++) {
>>>> +        /* Extract the offset value using bit-mask */
>>>> +        if (data->ct_offsets[i] == -1 && i == 1) {
>>>> +            /* 25C offset Case of Sensor 2 split between 2 regs */
>>>> +            tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29);
>>>> +            tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3);
>>>> +            pow = tmp & 0x80;
>>>> +        } else if (data->ct_offsets[i] == -1 && i == 2) {
>>>> +            /* 125C Case of Sensor 3 split between 2 regs */
>>>> +            tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27);
>>>> +            tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5);
>>>> +            pow = tmp & 0x100;
>>>> +        } else {
>>>> +            tmp = readl(bgp->fuse_base + data->ct_offsets[i]);
>>>> +            tmp &= data->ct_bm[i];
>>>> +            tmp = tmp >> __ffs(data->ct_bm[i]);
>>>> +
>>>> +            /* Obtain the sign bit pow*/
>>>> +            pow = data->ct_bm[i] >> __ffs(data->ct_bm[i]);
>>>> +            pow += 1;
>>>> +            pow /= 2;
>>>> +        }
>>>> +
>>>> +        /* Check for negative value */
>>>> +        if (tmp & pow) {
>>>> +            /* 2's complement value */
>>>> +            tmp = two_cmp(tmp, data->ct_bm[i] >>
>>>> __ffs(data->ct_bm[i]));
>>>> +        }
>>>> +        err[i] = tmp;
>>>> +    }
>>>> +}
>>>> +
>>>> +#ifdef DEBUG_VTM
>>>> +static void print_look_up_table(struct device *dev)
>>>> +{
>>>> +    int i;
>>>> +
>>>> +    dev_info(dev, "The contents of derived array\n");
>>>> +    dev_info(dev, "Code   Temperaturei\n");
>>>> +    for (i = 0; i <= 1023; i++)
>>>> +        dev_info(dev, "%d       %d\n", i, derived_array[i]);
>>>> +}
>>>> +#endif
>>>> +
>>>> +static const struct of_device_id of_k3_j72xx_bandgap_match[];
>>>> +
>>>> +struct k3_j72xx_bandgap_j72xx_data {
>>>> +    unsigned int    workaround;
>>>> +};
>>>> +
>>>> +static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
>>>> +{
>>>> +    int ret = 0, cnt, val, id, reg_cnt = 0, j;
>>>> +    int err[3], high_max, low_max;
>>>> +    struct resource *res;
>>>> +    struct device *dev = &pdev->dev;
>>>> +    struct k3_j72xx_bandgap *bgp;
>>>> +    struct k3_thermal_data *data;
>>>> +    int workaround_needed = 0;
>>>> +    const struct of_device_id *of_id;
>>>> +    const struct k3_j72xx_bandgap_j72xx_data *driver_data;
>>>> +
>>>> +    bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
>>>> +    if (!bgp)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    bgp->dev = dev;
>>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>> +    bgp->base = devm_ioremap_resource(dev, res);
>>>> +    if (IS_ERR(bgp->base))
>>>> +        return PTR_ERR(bgp->base);
>>>> +
>>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>>>> +    bgp->cfg2_base = devm_ioremap_resource(dev, res);
>>>> +    if (IS_ERR(bgp->cfg2_base))
>>>> +        return PTR_ERR(bgp->cfg2_base);
>>>> +
>>>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
>>>> +    bgp->fuse_base = devm_ioremap_resource(dev, res);
>>>> +    if (IS_ERR(bgp->fuse_base))
>>>> +        return PTR_ERR(bgp->fuse_base);
>>>> +
>>>> +    of_id = of_match_device(of_k3_j72xx_bandgap_match, &pdev->dev);
>>>> +    if (of_id) {
>>>> +        driver_data = of_id->data;
>>>> +        workaround_needed = driver_data->workaround;
>>>> +    }
>>>> +
>>>> +    pm_runtime_enable(dev);
>>>> +    ret = pm_runtime_get_sync(dev);
>>>> +    if (ret < 0) {
>>>> +        pm_runtime_put_noidle(dev);
>>>> +        pm_runtime_disable(dev);
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    /* Get the sensor count in the VTM */
>>>> +    val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
>>>> +    cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
>>>> +    cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
>>>> +    bgp->ts_cnt = cnt;
>>>> +
>>>> +    data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
>>>> +    if (!data) {
>>>> +        ret = -ENOMEM;
>>>> +        goto err_alloc;
>>>> +    }
>>>> +
>>>> +    /* Workaround not needed if bit30/bit31 is set even for J721e */
>>>> +    if (workaround_needed && (readl(bgp->fuse_base + 0x0) &
>>>> 0xc0000000) == 0xc0000000) {
>>>> +        dev_info(bgp->dev, "work around NOT needed!!\n");
>>>> +        workaround_needed = 0;
>>>> +    }
>>>> +
>>>> +    /* Register the thermal sensors */
>>>> +    for (id = 0; id < cnt; id++) {
>>>> +        data[id].sensor_id = id;
>>>> +        data[id].bgp = bgp;
>>>> +        data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
>>>> +        data[id].stat_offset = data[id].ctrl_offset +
>>>> +                    K3_VTM_TMPSENS_STAT_OFFSET;
>>>> +
>>>> +        if (!workaround_needed)
>>>> +            goto prepare_lookup;
>>>> +        /* ref adc values for -40C, 30C & 125C respectively */
>>>> +        data[id].ref_adc_val[0] = MINUS40CREF;
>>>> +        data[id].ref_adc_val[1] = PLUS30CREF;
>>>> +        data[id].ref_adc_val[2] = PLUS125CREF;
>>>> +        get_efuse_values(id, &data[id], err, bgp);
>>>> +
>>>> +prepare_lookup:
>>>> +        if (id == 0 && workaround_needed) {
>>>> +            prep_lookup_table(err[0], err[1], err[2], 0);
>>>> +        } else if (id == 0 && !workaround_needed) {
>>>> +            for (j = 0; j < (sizeof(pvt_poly_golden) / 4); j++)
>>>> +                derived_array[j] = pvt_poly_golden[j];
>>>> +        }
>>>> +
>>>> +        val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
>>>> +        val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
>>>> +            K3_VTM_TMPSENS_CTRL_SOC |
>>>> +            K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
>>>> +        writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
>>>> +
>>>> +        bgp->ts_data[id] = &data[id];
>>>> +        data[id].ti_thermal =
>>>> +        devm_thermal_zone_of_sensor_register(bgp->dev, id,
>>>> +                             &data[id],
>>>> +                             &k3_of_thermal_ops);
>>>> +        if (IS_ERR(data[id].ti_thermal)) {
>>>> +            dev_err(bgp->dev, "thermal zone device is NULL\n");
>>>> +            ret = PTR_ERR(data[id].ti_thermal);
>>>> +            goto err_alloc;
>>>> +        }
>>>> +
>>>> +        reg_cnt++;
>>>> +
>>>> +        /* Initialize Previous temp */
>>>> +        k3_thermal_get_temp(&data[id], &data[id].prev_temp);
>>>> +    }
>>>> +
>>>> +    /*
>>>> +     * Program TSHUT thresholds
>>>> +     * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
>>>> +     * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN  bit
>>>> +     *         This is already taken care as per of init
>>>> +     * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN  bit
>>>> +     */
>>>> +    high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
>>>> +    low_max = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
>>>> +
>>>> +    writel((low_max << 16) | high_max, data[0].bgp->cfg2_base +
>>>> +           K3_VTM_MISC_CTRL2_OFFSET);
>>>> +    mdelay(100);
>>>> +    writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
>>>> +           K3_VTM_MISC_CTRL_OFFSET);
>>>> +
>>>> +    platform_set_drvdata(pdev, bgp);
>>>> +
>>>> +#ifdef DEBUG_VTM
>>>> +    print_look_up_table(dev);
>>>> +#endif
>>>> +    return 0;
>>>> +
>>>> +err_alloc:
>>>> +    pm_runtime_put_sync(&pdev->dev);
>>>> +    pm_runtime_disable(&pdev->dev);
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
>>>> +{
>>>> +    pm_runtime_put_sync(&pdev->dev);
>>>> +    pm_runtime_disable(&pdev->dev);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j721e_data
>>>> = {
>>>> +    .workaround = 1,
>>>> +};
>>>> +
>>>> +const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j7200_data
>>>> = {
>>>> +    .workaround = 0,
>>>> +};
>>>> +
>>>> +static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
>>>> +    {
>>>> +        .compatible = "ti,j721e-vtm",
>>>> +        .data = (void *)&k3_j72xx_bandgap_j721e_data,
>>>> +    },
>>>> +    {
>>>> +        .compatible = "ti,j7200-vtm",
>>>> +        .data = (void *)&k3_j72xx_bandgap_j7200_data,
>>>> +    },
>>>> +    { /* sentinel */ },
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
>>>> +
>>>> +static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
>>>> +    .probe = k3_j72xx_bandgap_probe,
>>>> +    .remove = k3_j72xx_bandgap_remove,
>>>> +    .driver = {
>>>> +        .name = "k3-j72xx-soc-thermal",
>>>> +        .of_match_table    = of_k3_j72xx_bandgap_match,
>>>> +    },
>>>> +};
>>>> +
>>>> +module_platform_driver(k3_j72xx_bandgap_sensor_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
>>>> +MODULE_LICENSE("GPL v2");
>>>> +MODULE_AUTHOR("J Keerthy <[e-mail]>");
>>>>
>>>
>>>
> 
>

Patch

diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 82fc3e616e54..6dcaf2028ddc 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -28,7 +28,7 @@  thermal_sys-$(CONFIG_CPU_IDLE_THERMAL)	+= cpuidle_cooling.o
 # devfreq cooling
 thermal_sys-$(CONFIG_DEVFREQ_THERMAL) += devfreq_cooling.o
 
-obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o
+obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o k3_j72xx_bandgap.o
 # platform thermal drivers
 obj-y				+= broadcom/
 obj-$(CONFIG_THERMAL_MMIO)		+= thermal_mmio.o
diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
new file mode 100644
index 000000000000..1aa048221291
--- /dev/null
+++ b/drivers/thermal/k3_j72xx_bandgap.c
@@ -0,0 +1,772 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI Bandgap temperature sensor driver for J72XX SoC Family
+ *
+ * Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pm_runtime.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+#include <linux/thermal.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+
+#define K3_VTM_DEVINFO_PWR0_OFFSET		0x4
+#define K3_VTM_DEVINFO_PWR0_CVD_CT_MASK		0xf
+#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK	0xf0
+#define K3_VTM_TMPSENS0_CTRL_OFFSET		0x300
+#define K3_VTM_MISC_CTRL_OFFSET			0xc
+#define K3_VTM_TMPSENS_STAT_OFFSET		0x8
+#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN		0x1
+#define K3_VTM_MISC_CTRL2_OFFSET		0x10
+#define K3_VTM_REGS_PER_TS			0x10
+#define K3_VTM_TS_STAT_DTEMP_MASK		0x3ff
+#define K3_VTM_MAX_NUM_TS			8
+#define K3_VTM_TMPSENS_CTRL_CBIASSEL		BIT(0)
+#define K3_VTM_TMPSENS_CTRL_SOC			BIT(5)
+#define K3_VTM_TMPSENS_CTRL_CLRZ		BIT(6)
+#define K3_VTM_TMPSENS_CTRL_CLKON_REQ		BIT(7)
+#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN	BIT(11)
+
+#define K3_VTM_CORRECTION_TEMP_CNT		3
+
+#define K3_VTM_ADC_BEGIN_VAL			6
+#define K3_VTM_ADC_END_VAL			944
+
+#define MINUS40CREF				5
+#define PLUS30CREF				253
+#define PLUS125CREF				730
+#define PLUS150CREF				940
+
+#define MAX_TEMP				123000
+#define COOL_DOWN_TEMP				105000
+
+//#define DEBUG_VTM
+
+static int derived_array[1024];
+
+/* Reference Look up table when work around is NOT needed */
+static const int pvt_poly_golden[] = {
+	-49002, -48677, -48352, -48028, -47704, -47381, -47057, -46734, -46412,
+	-46090, -45768, -45446, -45125, -44804, -44484, -44163, -43844, -43524,
+	-43205, -42886, -42567, -42249, -41931, -41614, -41297, -40980, -40663,
+	-40347, -40031, -39716, -39400, -39085, -38771, -38457, -38143, -37829,
+	-37516, -37203, -36890, -36578, -36266, -35955, -35643, -35332, -35022,
+	-34712, -34402, -34092, -33783, -33474, -33165, -32857, -32549, -32241,
+	-31934, -31626, -31320, -31013, -30707, -30401, -30096, -29791, -29486,
+	-29182, -28877, -28573, -28270, -27967, -27664, -27361, -27059, -26757,
+	-26455, -26154, -25853, -25552, -25252, -24952, -24652, -24353, -24054,
+	-23755, -23456, -23158, -22860, -22563, -22265, -21968, -21672, -21376,
+	-21079, -20784, -20488, -20193, -19899, -19604, -19310, -19016, -18723,
+	-18429, -18136, -17844, -17551, -17259, -16968, -16676, -16385, -16094,
+	-15804, -15514, -15224, -14934, -14645, -14356, -14067, -13779, -13491,
+	-13203, -12916, -12628, -12342, -12055, -11769, -11483, -11197, -10912,
+	-10627, -10342, -10057, -9773, -9489, -9206, -8922, -8639, -8357, -8074,
+	-7792, -7510, -7229, -6947, -6666, -6386, -6105, -5825, -5546, -5266,
+	-4987, -4708, -4429, -4151, -3873, -3595, -3318, -3041, -2764, -2487,
+	-2211, -1935, -1659, -1384, -1108, -834, -559, -285, -11, 263, 537, 810,
+	1083, 1355, 1628, 1900, 2171, 2443, 2714, 2985, 3255, 3526, 3796, 4066,
+	4335, 4604, 4873, 5142, 5410, 5679, 5946, 6214, 6481, 6748, 7015, 7281,
+	7548, 7813, 8079, 8344, 8609, 8874, 9139, 9403, 9667, 9931, 10194,
+	10457, 10720, 10983, 11245, 11507, 11769, 12030, 12292, 12553, 12813,
+	13074, 13334, 13594, 13854, 14113, 14372, 14631, 14889, 15148, 15406,
+	15664, 15921, 16178, 16435, 16692, 16948, 17205, 17461, 17716, 17972,
+	18227, 18482, 18736, 18991, 19245, 19498, 19752, 20005, 20258, 20511,
+	20764, 21016, 21268, 21520, 21771, 22022, 22273, 22524, 22774, 23025,
+	23274, 23524, 23774, 24023, 24272, 24520, 24769, 25017, 25265, 25512,
+	25760, 26007, 26254, 26500, 26747, 26993, 27239, 27484, 27730, 27975,
+	28220, 28464, 28708, 28953, 29196, 29440, 29683, 29927, 30169, 30412,
+	30654, 30896, 31138, 31380, 31621, 31862, 32103, 32344, 32584, 32824,
+	33064, 33304, 33543, 33783, 34022, 34260, 34499, 34737, 34975, 35213,
+	35450, 35687, 35924, 36161, 36397, 36634, 36870, 37105, 37341, 37576,
+	37811, 38046, 38281, 38515, 38749, 38983, 39217, 39450, 39683, 39916,
+	40149, 40381, 40614, 40846, 41077, 41309, 41540, 41771, 42002, 42233,
+	42463, 42693, 42923, 43153, 43382, 43611, 43840, 44069, 44297, 44526,
+	44754, 44981, 45209, 45436, 45663, 45890, 46117, 46343, 46570, 46796,
+	47021, 47247, 47472, 47697, 47922, 48147, 48371, 48595, 48819, 49043,
+	49266, 49490, 49713, 49935, 50158, 50380, 50603, 50824, 51046, 51268,
+	51489, 51710, 51931, 52151, 52372, 52592, 52812, 53031, 53251, 53470,
+	53689, 53908, 54127, 54345, 54563, 54781, 54999, 55217, 55434, 55651,
+	55868, 56085, 56301, 56517, 56733, 56949, 57165, 57380, 57595, 57810,
+	58025, 58239, 58454, 58668, 58882, 59095, 59309, 59522, 59735, 59948,
+	60160, 60373, 60585, 60797, 61009, 61220, 61432, 61643, 61854, 62064,
+	62275, 62485, 62695, 62905, 63115, 63324, 63534, 63743, 63952, 64160,
+	64369, 64577, 64785, 64993, 65200, 65408, 65615, 65822, 66029, 66236,
+	66442, 66648, 66854, 67060, 67266, 67471, 67676, 67881, 68086, 68291,
+	68495, 68699, 68903, 69107, 69311, 69514, 69717, 69920, 70123, 70326,
+	70528, 70730, 70932, 71134, 71336, 71537, 71738, 71939, 72140, 72341,
+	72541, 72742, 72942, 73142, 73341, 73541, 73740, 73939, 74138, 74337,
+	74535, 74733, 74932, 75130, 75327, 75525, 75722, 75919, 76116, 76313,
+	76510, 76706, 76902, 77098, 77294, 77490, 77685, 77881, 78076, 78271,
+	78465, 78660, 78854, 79048, 79242, 79436, 79630, 79823, 80016, 80210,
+	80402, 80595, 80788, 80980, 81172, 81364, 81556, 81747, 81939, 82130,
+	82321, 82512, 82702, 82893, 83083, 83273, 83463, 83653, 83843, 84032,
+	84221, 84410, 84599, 84788, 84976, 85165, 85353, 85541, 85728, 85916,
+	86103, 86291, 86478, 86665, 86851, 87038, 87224, 87411, 87597, 87782,
+	87968, 88154, 88339, 88524, 88709, 88894, 89078, 89263, 89447, 89631,
+	89815, 89999, 90182, 90366, 90549, 90732, 90915, 91098, 91280, 91463,
+	91645, 91827, 92009, 92191, 92372, 92554, 92735, 92916, 93097, 93277,
+	93458, 93638, 93818, 93998, 94178, 94358, 94537, 94717, 94896, 95075,
+	95254, 95433, 95611, 95790, 95968, 96146, 96324, 96501, 96679, 96856,
+	97033, 97211, 97387, 97564, 97741, 97917, 98093, 98269, 98445, 98621,
+	98797, 98972, 99147, 99322, 99497, 99672, 99847, 100021, 100196, 100370,
+	100544, 100718, 100891, 101065, 101238, 101411, 101584, 101757, 101930,
+	102103, 102275, 102447, 102619, 102791, 102963, 103135, 103306, 103478,
+	103649, 103820, 103991, 104161, 104332, 104502, 104673, 104843, 105013,
+	105182, 105352, 105522, 105691, 105860, 106029, 106198, 106367, 106535,
+	106704, 106872, 107040, 107208, 107376, 107544, 107711, 107878, 108046,
+	108213, 108380, 108546, 108713, 108880, 109046, 109212, 109378, 109544,
+	109710, 109875, 110041, 110206, 110371, 110536, 110701, 110866, 111030,
+	111195, 111359, 111523, 111687, 111851, 112015, 112178, 112342, 112505,
+	112668, 112831, 112994, 113157, 113319, 113482, 113644, 113806, 113968,
+	114130, 114292, 114453, 114615, 114776, 114937, 115098, 115259, 115420,
+	115580, 115741, 115901, 116061, 116221, 116381, 116541, 116701, 116860,
+	117019, 117179, 117338, 117497, 117655, 117814, 117973, 118131, 118289,
+	118447, 118605, 118763, 118921, 119078, 119236, 119393, 119550, 119707,
+	119864, 120021, 120178, 120334, 120490, 120647, 120803, 120959, 121115,
+	121270, 121426, 121581, 121737, 121892, 122047, 122202, 122356, 122511,
+	122666, 122820, 122974, 123128, 123282, 123436, 123590, 123744, 123897,
+	124050, 124204, 124357, 124510, 124662, 124815, 124968, 125120, 125273,
+	125425, 125577, 125729, 125881, 126032, 126184, 126335, 126487, 126638,
+	126789, 126940, 127091, 127241, 127392, 127542, 127693, 127843, 127993,
+	128143, 128293, 128442, 128592, 128741, 128891, 129040, 129189, 129338,
+	129487, 129635, 129784, 129932, 130081, 130229, 130377, 130525, 130673,
+	130821, 130968, 131116, 131263, 131410, 131558, 131705, 131851, 131998,
+	132145, 132291, 132438, 132584, 132730, 132876, 133022, 133168, 133314,
+	133460, 133605, 133750, 133896, 134041, 134186, 134331, 134476, 134620,
+	134765, 134909, 135054, 135198, 135342, 135486, 135630, 135773, 135917,
+	136061, 136204, 136347, 136491, 136634, 136777, 136919, 137062, 137205,
+	137347, 137490, 137632, 137774, 137916, 138058, 138200, 138342, 138483,
+	138625, 138766, 138907, 139049, 139190, 139331, 139471, 139612, 139753,
+	139893, 140034, 140174, 140314, 140454, 140594, 140734, 140874, 141013,
+	141153, 141292, 141432, 141571, 141710, 141849, 141988, 142127, 142265,
+	142404, 142542, 142681, 142819, 142957, 143095, 143233, 143371, 143509,
+	143646, 143784, 143921, 144058, 144196, 144333, 144470, 144607, 144743,
+	144880, 145017, 145153, 145289, 145426, 145562, 145698, 145834, 145970,
+	146105, 146241, 146377, 146512, 146647, 146783, 146918, 147053, 147188,
+	147323, 147457, 147592, 147727, 147861, 147995, 148130, 148264, 148398,
+	148532, 148666, 148799, 148933, 149067, 149200, 149333, 149467, 149600,
+	149733, 149866, 149999, 150131, 150264, 150397, 150529, 150661, 150794,
+	150926, 151058, 151190, 151322, 151454, 151585, 151717, 151848, 151980,
+	152111,	152242, 152373, 152505, 152635, 152766, 152897, 153028, 153158,
+	153289, 153419, 153549, 153680, 153810, 153940, 154070, 154199, 154329,
+	154459, 154588, 154718, 154847, 154976, 155105, 155235, 155363, 155492,
+	155621, 155750, 155879, 156007, 156135, 156264, 156392, 156520, 156648,
+	156776, 156904, 157032, 157160, 157287, 157415, 157542, 157670, 157797,
+	157924, 158051, 158178, 158305, 158432, 158559, 158685, 158812, 158938,
+	159065, 159191, 159317, 159443, 159569,
+};
+
+/* Reference Look up table when work around is needed */
+static const int pvt_poly[] = {
+	-41523, -41210, -40898, -40586, -40274, -39963, -39651, -39340,	-39029,
+	-38718, -38408, -38098, -37788, -37478, -37168, -36859, -36550, -36241,
+	-35933, -35624, -35316, -35008, -34701, -34393, -34086, -33779, -33472,
+	-33166, -32859, -32553, -32247, -31942, -31636, -31331, -31026, -30722,
+	-30417, -30113, -29809, -29505, -29202, -28899, -28596, -28293, -27990,
+	-27688, -27386, -27084, -26782, -26481, -26179, -25878, -25578, -25277,
+	-24977, -24677, -24377, -24078, -23778, -23479, -23180, -22882, -22583,
+	-22285, -21987, -21689, -21392, -21095, -20797, -20501, -20204, -19908,
+	-19612, -19316, -19020, -18725, -18430, -18135, -17840, -17545, -17251,
+	-16957, -16663, -16370, -16077, -15783, -15491, -15198,	-14906, -14613,
+	-14321, -14030, -13738, -13447, -13156, -12865, -12575, -12284, -11994,
+	-11704, -11415, -11125, -10836, -10547, -10259, -9970, -9682, -9394,
+	-9106, -8819, -8531, -8244, -7957, -7671, -7384, -7098, -6812, -6527,
+	-6241, -5956, -5671, -5386, -5102, -4817, -4533, -4250, -3966, -3683,
+	-3399, -3117, -2834, -2551, -2269, -1987, -1706, -1424, -1143, -862,
+	-581, -300, -20, 260, 540, 820, 1099, 1378, 1657, 1936, 2215, 2493,
+	2771, 3049, 3326, 3604, 3881, 4158, 4434, 4711, 4987, 5263, 5539, 5814,
+	6089, 6364, 6639, 6914, 7188, 7462, 7736, 8010, 8283, 8556, 8829, 9102,
+	9374, 9647, 9919, 10191, 10462, 10733, 11005, 11275, 11546, 11816,
+	12087, 12357, 12626, 12896, 13165, 13434, 13703, 13971, 14240, 14508,
+	14776, 15043, 15311, 15578, 15845, 16111, 16378, 16644, 16910, 17176,
+	17441, 17707, 17972, 18237, 18501, 18766, 19030, 19294, 19557, 19821,
+	20084, 20347, 20610, 20872, 21135, 21397, 21658, 21920, 22181, 22443,
+	22703, 22964, 23225, 23485, 23745, 24005, 24264, 24523, 24782, 25041,
+	25300, 25558, 25816, 26074, 26332, 26589, 26846, 27103, 27360, 27617,
+	27873, 28129, 28385, 28640, 28896, 29151, 29406, 29660, 29915, 30169,
+	30423, 30677, 30930, 31183, 31437, 31689, 31942, 32194, 32446, 32698,
+	32950, 33201, 33452, 33703, 33954, 34205, 34455, 34705, 34955, 35204,
+	35454, 35703, 35952, 36200, 36449, 36697, 36945, 37192, 37440, 37687,
+	37934, 38181, 38427, 38674, 38920, 39166, 39411, 39657, 39902, 40147,
+	40391, 40636, 40880, 41124, 41368, 41611, 41855, 42098, 42341, 42583,
+	42826, 43068, 43310, 43551, 43793, 44034, 44275, 44516, 44756, 44997,
+	45237, 45477, 45716, 45956, 46195, 46434, 46672, 46911, 47149, 47387,
+	47625, 47862, 48100, 48337, 48573, 48810, 49046, 49282, 49518, 49754,
+	49989, 50225, 50460, 50694, 50929, 51163, 51397, 51631, 51865, 52098,
+	52331, 52564, 52797, 53029, 53261, 53493, 53725, 53956, 54188, 54419,
+	54650, 54880, 55110, 55341, 55570, 55800, 56030, 56259, 56488, 56716,
+	56945, 57173, 57401, 57629, 57856, 58084, 58311, 58538, 58764, 58991,
+	59217, 59443, 59669, 59894, 60119, 60344, 60569, 60794, 61018, 61242,
+	61466, 61690, 61913, 62136, 62359, 62582, 62804, 63026, 63249, 63470,
+	63692, 63913, 64134, 64355, 64576, 64796, 65016, 65236, 65456, 65675,
+	65894, 66113, 66332, 66551, 66769, 66987, 67205, 67423, 67640, 67857,
+	68074, 68291, 68507, 68723, 68939, 69155, 69371, 69586, 69801, 70016,
+	70230, 70445, 70659, 70873, 71086, 71300, 71513, 71726, 71939, 72151,
+	72364, 72576, 72787, 72999, 73210, 73422, 73632, 73843, 74053, 74264,
+	74474, 74683, 74893, 75102, 75311, 75520, 75729, 75937, 76145, 76353,
+	76561, 76768, 76975, 77182, 77389, 77595, 77802, 78008, 78213, 78419,
+	78624, 78829, 79034, 79239, 79443, 79647, 79851, 80055, 80259, 80462,
+	80665, 80868, 81070, 81273, 81475, 81676, 81878, 82079, 82281, 82482,
+	82682, 82883, 83083, 83283, 83483, 83682, 83882, 84081, 84280, 84478,
+	84677, 84875, 85073, 85270, 85468, 85665, 85862, 86059, 86255, 86452,
+	86648, 86844, 87039, 87234, 87430, 87625, 87819, 88014, 88208, 88402,
+	88596, 88789, 88982, 89175, 89368, 89561, 89753, 89945, 90137, 90329,
+	90520, 90712, 90903, 91093, 91284, 91474, 91664, 91854, 92044, 92233,
+	92422, 92611, 92800, 92988, 93176, 93364, 93552, 93739, 93927, 94114,
+	94301, 94487, 94673, 94860, 95045, 95231, 95417, 95602, 95787, 95971,
+	96156, 96340, 96524, 96708, 96892, 97075, 97258, 97441, 97624, 97806,
+	97988, 98170, 98352, 98533, 98714, 98895, 99076, 99257, 99437, 99617,
+	99797, 99977, 100156, 100335, 100514, 100693, 100871, 101050, 101228,
+	101405, 101583, 101760, 101937, 102114, 102291, 102467, 102643, 102819,
+	102995, 103170, 103346, 103521, 103695, 103870, 104044, 104218, 104392,
+	104566, 104739, 104912, 105085, 105258, 105430, 105603, 105775, 105946,
+	106118, 106289, 106460, 106631, 106802, 106972, 107142, 107312, 107482,
+	107651, 107820, 107989, 108158, 108327, 108495, 108663, 108831, 108998,
+	109166, 109333, 109500, 109666, 109833, 109999, 110165, 110331, 110496,
+	110661, 110827, 110991, 111156, 111320, 111484, 111648, 111812, 111975,
+	112139, 112301, 112464, 112627, 112789, 112951, 113113, 113274, 113436,
+	113597, 113758, 113918, 114079, 114239, 114399, 114559, 114718, 114877,
+	115036, 115195, 115354, 115512, 115670, 115828, 115986, 116143, 116300,
+	116457, 116614, 116770, 116926, 117082, 117238, 117394, 117549, 117704,
+	117859, 118014, 118168, 118322, 118476, 118630, 118783, 118937, 119090,
+	119242, 119395, 119547, 119699, 119851, 120003, 120154, 120305, 120456,
+	120607, 120757, 120907, 121057, 121207, 121357, 121506, 121655, 121804,
+	121953, 122101, 122249, 122397, 122545, 122692, 122839, 122986, 123133,
+	123280, 123426, 123572, 123718, 123863, 124009, 124154, 124299, 124443,
+	124588, 124732, 124876, 125020, 125163, 125306, 125449, 125592, 125735,
+	125877, 126019, 126161, 126303, 126444, 126585, 126726, 126867, 127008,
+	127148, 127288, 127428, 127567, 127707, 127846, 127985, 128123, 128262,
+	128400, 128538, 128676, 128813, 128950, 129087, 129224, 129361, 129497,
+	129633, 129769, 129905, 130040, 130175, 130310, 130445, 130579, 130713,
+	130847, 130981, 131115, 131248, 131381, 131514, 131647, 131779, 131911,
+	132043, 132175, 132306, 132438, 132569, 132699, 132830, 132960, 133090,
+	133220, 133350, 133479, 133608, 133737, 133866, 133994, 134123, 134251,
+	134378, 134506, 134633, 134760, 134887, 135014, 135140, 135266, 135392,
+	135518, 135643, 135768, 135893, 136018, 136143, 136267, 136391, 136515,
+	136638, 136762, 136885, 137008, 137130, 137253, 137375, 137497, 137619,
+	137740, 137862, 137983, 138103, 138224, 138344, 138464, 138584, 138704,
+	138823, 138943, 139062, 139180, 139299, 139417, 139535, 139653, 139770,
+	139888, 140005, 140122, 140238, 140355, 140471, 140587, 140703, 140818,
+	140933, 141048, 141163, 141278, 141392, 141506, 141620, 141734, 141847,
+	141960, 142073, 142186, 142298, 142411, 142523, 142634, 142746, 142857,
+	142968, 143079, 143190, 143300, 143410, 143520, 143630, 143740, 143849,
+	143958, 144067, 144175, 144283, 144391, 144499, 144607, 144714, 144821,
+	144928, 145035, 145142, 145248, 145354, 145459, 145565, 145670, 145775,
+	145880, 145985, 146089, 146193, 146297, 146401, 146504, 146608, 146711,
+	146813, 146916, 147018, 147120, 147222, 147324, 147425, 147526, 147627,
+	147728, 147828, 147928, 148028, 148128, 148228, 148327, 148426, 148525,
+	148623, 148722, 148820, 148918, 149015, 149113, 149210, 149307, 149404,
+	149500, 149596, 149692, 149788, 149884, 149979, 150074, 150169, 150264,
+	150358, 150452, 150546, 150640, 150733, 150827, 150920, 151013, 151105,
+	151197, 151290, 151381, 151473, 151564, 151656, 151747, 151837, 151928,
+	152018, 152108, 152198, 152287, 152377, 152466, 152555, 152643, 152732,
+	152820, 152908, 152995, 153083, 153170, 153257, 153344, 153430, 153517,
+	153603, 153689, 153774, 153860, 153945, 154030, 154114, 154199, 154283,
+	154367, 154451, 154534, 154618, 154701, 154784, 154866, 154949, 155031,
+	155113, 155194, 155276, 155357, 155438, 155519, 155599, 155680, 155760,
+	155839, 155919, 155998, 156078, 156156, 156235, 156314, 156392, 156470,
+	156547, 156625, 156702, 156779, 156856, 156933, 157009, 157085, 157161,
+};
+
+static void fill_table(int err1, int err2, int ref1, int ref2, int idx1,
+		       int idx2)
+{
+	int m, c, num, den, i, err;
+
+	/**
+	 * Calculate the slope with adc values read from the register
+	 * as the y-axis param and err in adc value as x-axis param
+	 */
+	if (err1 != err2) {
+		num = ref2 - ref1;
+		den = err2 - err1;
+		m = num / den;
+		c = ref2 - m * err2;
+		for (i = idx1; i <= idx2; i++) {
+			err = (i - c) / m;
+			if (((i + err1) < 0) || ((i + err1) > 1023))
+				continue;
+			derived_array[i] = pvt_poly[i + err];
+		}
+	} else { /* Constant error take care of divide by zero */
+		for (i = idx1; i < idx2; i++) {
+			if (((i + err1) < 0) || ((i + err1) > 1023))
+				continue;
+			derived_array[i] = pvt_poly[i + err1];
+		}
+	}
+}
+
+static int prep_lookup_table(int minus40cerr, int plus30cerr, int plus125cerr,
+			     int plus150cerr)
+{
+	int start_temp, inc, i;
+
+	/* Fill up the lookup table region -40C to +30C */
+	fill_table(minus40cerr, plus30cerr, MINUS40CREF, PLUS30CREF, 0,
+		   PLUS30CREF);
+	/* Fill up the lookup table region +30C to +125C */
+	fill_table(plus30cerr, plus125cerr, PLUS30CREF, PLUS125CREF, PLUS30CREF,
+		   PLUS125CREF);
+	/* Fill up the lookup table region +125C to +150C */
+	fill_table(plus125cerr, plus150cerr, PLUS125CREF, PLUS150CREF, PLUS125CREF,
+		   PLUS150CREF);
+
+	/* Get to the first valid temperature */
+	i = 0;
+	while (!derived_array[i])
+		i++;
+
+	start_temp = i;
+	/*
+	 * Get to the last zero index and back fill the temperature for
+	 * sake of continuity
+	 */
+	if (i) {
+		/* 300 milli celsius steps */
+		while (i--)
+			derived_array[i] = derived_array[i + 1] - 300;
+		/* case 0 */
+		derived_array[i] = derived_array[i + 1] - 300;
+	}
+
+	/*
+	 * Fill the last trailing 0s which are unfilled with increments of
+	 * 100 milli celsius till 1023 code
+	 */
+	i = 1023;
+	while (!derived_array[i])
+		i--;
+
+	i++;
+	inc = 1;
+	while (i < 1024) {
+		derived_array[i] = derived_array[i - 1] + inc * 100;
+		i++;
+	}
+
+	return 0;
+}
+
+struct k3_thermal_data;
+
+struct k3_j72xx_bandgap {
+	struct device *dev;
+	void __iomem *base;
+	void __iomem *cfg2_base;
+	void __iomem *fuse_base;
+	const struct k3_j72xx_bandgap_data	*conf;
+	spinlock_t lock; /* shields this struct */
+	int ts_cnt;
+	struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
+};
+
+/* common data structures */
+struct k3_thermal_data {
+	struct thermal_zone_device *ti_thermal;
+	struct thermal_cooling_device *cool_dev;
+	struct k3_j72xx_bandgap *bgp;
+	enum thermal_device_mode mode;
+	int sensor_id;
+	u32 ctrl_offset;
+	u32 stat_offset;
+	int prev_temp;
+	int ct_offsets[K3_VTM_CORRECTION_TEMP_CNT];
+	int ct_bm[K3_VTM_CORRECTION_TEMP_CNT];
+	int ref_adc_val[3];
+	int act_adc_val[3];
+	int slope[2];
+	int coeff[2];
+};
+
+int two_cmp(int tmp, int mask)
+{
+	tmp = ~(tmp);
+	tmp &= mask;
+	tmp += 1;
+
+	/* Return negative value */
+	return (0 - tmp);
+}
+
+static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
+				       unsigned int s2)
+{
+	int d01 = abs(s0 - s1);
+	int d02 = abs(s0 - s2);
+	int d12 = abs(s1 - s2);
+
+	if (d01 <= d02 && d01 <= d12)
+		return (s0 + s1) / 2;
+
+	if (d02 <= d01 && d02 <= d12)
+		return (s0 + s2) / 2;
+
+	return (s1 + s2) / 2;
+}
+
+static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
+				   int *temp)
+{
+	struct k3_j72xx_bandgap *bgp;
+	unsigned int dtemp, s0, s1, s2;
+
+	bgp = devdata->bgp;
+	/*
+	 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There
+	 * is a variation of the order for certain degree centigrade on AM654.
+	 * Work around that by getting the average of two closest
+	 * readings out of three readings everytime we want to
+	 * report temperatures.
+	 *
+	 * Errata workaround.
+	 */
+	s0 = readl(bgp->base + devdata->stat_offset) &
+		K3_VTM_TS_STAT_DTEMP_MASK;
+	s1 = readl(bgp->base + devdata->stat_offset) &
+		K3_VTM_TS_STAT_DTEMP_MASK;
+	s2 = readl(bgp->base + devdata->stat_offset) &
+		K3_VTM_TS_STAT_DTEMP_MASK;
+	dtemp = vtm_get_best_value(s0, s1, s2);
+
+	if (dtemp < 0 || dtemp > 1023)
+		return -EINVAL;
+
+	*temp = derived_array[dtemp];
+
+	return 0;
+}
+
+/* Get temperature callback function for thermal zone */
+static int k3_thermal_get_temp(void *devdata, int *temp)
+{
+	struct k3_thermal_data *data = devdata;
+	int ret = 0;
+
+	ret = k3_bgp_read_temp(data, temp);
+	if (ret)
+		return ret;
+
+	data->prev_temp = *temp;
+
+	return ret;
+}
+
+static const struct thermal_zone_of_device_ops k3_of_thermal_ops = {
+	.get_temp = k3_thermal_get_temp,
+};
+
+static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
+{
+	int low = 0, high = 1023, mid;
+
+	if (temp > 160000 || temp < -50000)
+		return -EINVAL;
+
+	/* Binary search to find the adc code */
+	while (low < (high - 1)) {
+		mid = (low + high) / 2;
+		if (temp <= derived_array[mid])
+			high = mid;
+		else
+			low = mid;
+	}
+
+	return mid;
+}
+
+static void get_efuse_values(int id, struct k3_thermal_data *data, int *err,
+			     struct k3_j72xx_bandgap *bgp)
+{
+	int i, tmp, pow;
+
+	/* Populate efuse reg offsets & Bit masks for -40C, 30C, 125C */
+	switch (id) {
+	case 0:
+		data->ct_offsets[0] = 0x0;
+		data->ct_offsets[1] = 0x8;
+		data->ct_offsets[2] = 0x4;
+		data->ct_bm[0] = 0x3f;
+		data->ct_bm[1] = 0x1fe000;
+		data->ct_bm[2] = 0x1ff;
+		break;
+
+	case 1:
+		data->ct_offsets[0] = 0x0;
+		data->ct_offsets[1] = 0x8;
+		data->ct_offsets[2] = 0x4;
+		data->ct_bm[0] = 0xfc0;
+		data->ct_bm[1] = 0x1fe00000;
+		data->ct_bm[2] = 0x3fe00;
+		break;
+
+	case 2:
+		data->ct_offsets[0] = 0x0;
+		data->ct_offsets[1] = -1;
+		data->ct_offsets[2] = 0x4;
+		data->ct_bm[0] = 0x3f000;
+		data->ct_bm[1] = 0x7f800000;
+		data->ct_bm[2] = 0x7fc0000;
+		break;
+
+	case 3:
+		data->ct_offsets[0] = 0x0;
+		data->ct_offsets[1] = 0xC;
+		data->ct_offsets[2] = -1; /* Spread across 2 registers */
+		data->ct_bm[0] = 0xfc0000;
+		data->ct_bm[1] = 0x1fe0;
+		data->ct_bm[2] = 0x1f800000;
+		break;
+
+	case 4:
+		data->ct_offsets[0] = 0x0;
+		data->ct_offsets[1] = 0xc;
+		data->ct_offsets[2] = 0x8;
+		data->ct_bm[0] = 0x3f000000;
+		data->ct_bm[1] = 0x1fe000;
+		data->ct_bm[2] = 0x1ff0;
+		break;
+	}
+
+	for (i = 0; i < 3; i++) {
+		/* Extract the offset value using bit-mask */
+		if (data->ct_offsets[i] == -1 && i == 1) {
+			/* 25C offset Case of Sensor 2 split between 2 regs */
+			tmp = (readl(bgp->fuse_base + 0x8) & 0xE0000000) >> (29);
+			tmp |= ((readl(bgp->fuse_base + 0xC) & 0x1F) << 3);
+			pow = tmp & 0x80;
+		} else if (data->ct_offsets[i] == -1 && i == 2) {
+			/* 125C Case of Sensor 3 split between 2 regs */
+			tmp = (readl(bgp->fuse_base + 0x4) & 0xF8000000) >> (27);
+			tmp |= ((readl(bgp->fuse_base + 0x8) & 0xF) << 5);
+			pow = tmp & 0x100;
+		} else {
+			tmp = readl(bgp->fuse_base + data->ct_offsets[i]);
+			tmp &= data->ct_bm[i];
+			tmp = tmp >> __ffs(data->ct_bm[i]);
+
+			/* Obtain the sign bit pow*/
+			pow = data->ct_bm[i] >> __ffs(data->ct_bm[i]);
+			pow += 1;
+			pow /= 2;
+		}
+
+		/* Check for negative value */
+		if (tmp & pow) {
+			/* 2's complement value */
+			tmp = two_cmp(tmp, data->ct_bm[i] >> __ffs(data->ct_bm[i]));
+		}
+		err[i] = tmp;
+	}
+}
+
+#ifdef DEBUG_VTM
+static void print_look_up_table(struct device *dev)
+{
+	int i;
+
+	dev_info(dev, "The contents of derived array\n");
+	dev_info(dev, "Code   Temperaturei\n");
+	for (i = 0; i <= 1023; i++)
+		dev_info(dev, "%d       %d\n", i, derived_array[i]);
+}
+#endif
+
+static const struct of_device_id of_k3_j72xx_bandgap_match[];
+
+struct k3_j72xx_bandgap_j72xx_data {
+	unsigned int	workaround;
+};
+
+static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
+{
+	int ret = 0, cnt, val, id, reg_cnt = 0, j;
+	int err[3], high_max, low_max;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	struct k3_j72xx_bandgap *bgp;
+	struct k3_thermal_data *data;
+	int workaround_needed = 0;
+	const struct of_device_id *of_id;
+	const struct k3_j72xx_bandgap_j72xx_data *driver_data;
+
+	bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
+	if (!bgp)
+		return -ENOMEM;
+
+	bgp->dev = dev;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bgp->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(bgp->base))
+		return PTR_ERR(bgp->base);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	bgp->cfg2_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(bgp->cfg2_base))
+		return PTR_ERR(bgp->cfg2_base);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	bgp->fuse_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(bgp->fuse_base))
+		return PTR_ERR(bgp->fuse_base);
+
+	of_id = of_match_device(of_k3_j72xx_bandgap_match, &pdev->dev);
+	if (of_id) {
+		driver_data = of_id->data;
+		workaround_needed = driver_data->workaround;
+	}
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		pm_runtime_disable(dev);
+		return ret;
+	}
+
+	/* Get the sensor count in the VTM */
+	val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
+	cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
+	cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
+	bgp->ts_cnt = cnt;
+
+	data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	/* Workaround not needed if bit30/bit31 is set even for J721e */
+	if (workaround_needed && (readl(bgp->fuse_base + 0x0) & 0xc0000000) == 0xc0000000) {
+		dev_info(bgp->dev, "work around NOT needed!!\n");
+		workaround_needed = 0;
+	}
+
+	/* Register the thermal sensors */
+	for (id = 0; id < cnt; id++) {
+		data[id].sensor_id = id;
+		data[id].bgp = bgp;
+		data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
+		data[id].stat_offset = data[id].ctrl_offset +
+					K3_VTM_TMPSENS_STAT_OFFSET;
+
+		if (!workaround_needed)
+			goto prepare_lookup;
+		/* ref adc values for -40C, 30C & 125C respectively */
+		data[id].ref_adc_val[0] = MINUS40CREF;
+		data[id].ref_adc_val[1] = PLUS30CREF;
+		data[id].ref_adc_val[2] = PLUS125CREF;
+		get_efuse_values(id, &data[id], err, bgp);
+
+prepare_lookup:
+		if (id == 0 && workaround_needed) {
+			prep_lookup_table(err[0], err[1], err[2], 0);
+		} else if (id == 0 && !workaround_needed) {
+			for (j = 0; j < (sizeof(pvt_poly_golden) / 4); j++)
+				derived_array[j] = pvt_poly_golden[j];
+		}
+
+		val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
+		val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
+			K3_VTM_TMPSENS_CTRL_SOC |
+			K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
+		writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
+
+		bgp->ts_data[id] = &data[id];
+		data[id].ti_thermal =
+		devm_thermal_zone_of_sensor_register(bgp->dev, id,
+						     &data[id],
+						     &k3_of_thermal_ops);
+		if (IS_ERR(data[id].ti_thermal)) {
+			dev_err(bgp->dev, "thermal zone device is NULL\n");
+			ret = PTR_ERR(data[id].ti_thermal);
+			goto err_alloc;
+		}
+
+		reg_cnt++;
+
+		/* Initialize Previous temp */
+		k3_thermal_get_temp(&data[id], &data[id].prev_temp);
+	}
+
+	/*
+	 * Program TSHUT thresholds
+	 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
+	 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN  bit
+	 *         This is already taken care as per of init
+	 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN  bit
+	 */
+	high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
+	low_max = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
+
+	writel((low_max << 16) | high_max, data[0].bgp->cfg2_base +
+	       K3_VTM_MISC_CTRL2_OFFSET);
+	mdelay(100);
+	writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
+	       K3_VTM_MISC_CTRL_OFFSET);
+
+	platform_set_drvdata(pdev, bgp);
+
+#ifdef DEBUG_VTM
+	print_look_up_table(dev);
+#endif
+	return 0;
+
+err_alloc:
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int k3_j72xx_bandgap_remove(struct platform_device *pdev)
+{
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j721e_data = {
+	.workaround = 1,
+};
+
+const struct k3_j72xx_bandgap_j72xx_data k3_j72xx_bandgap_j7200_data = {
+	.workaround = 0,
+};
+
+static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
+	{
+		.compatible = "ti,j721e-vtm",
+		.data = (void *)&k3_j72xx_bandgap_j721e_data,
+	},
+	{
+		.compatible = "ti,j7200-vtm",
+		.data = (void *)&k3_j72xx_bandgap_j7200_data,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
+
+static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
+	.probe = k3_j72xx_bandgap_probe,
+	.remove = k3_j72xx_bandgap_remove,
+	.driver = {
+		.name = "k3-j72xx-soc-thermal",
+		.of_match_table	= of_k3_j72xx_bandgap_match,
+	},
+};
+
+module_platform_driver(k3_j72xx_bandgap_sensor_driver);
+
+MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("J Keerthy <[e-mail]>");