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[1/2] iio: temperature: Adding support for MLX90632

Message ID 20171129220749.11301-1-cmo@melexis.com (mailing list archive)
State New, archived
Headers show

Commit Message

Crt Mori Nov. 29, 2017, 10:07 p.m. UTC
Melexis has just released Infra Red temperature sensor MLX90632 used
for contact-less temperature measurement. Driver provides basic
functionality for reporting object (and ambient) temperature with
support for object emissivity.

Signed-off-by: Crt Mori <cmo@melexis.com>
---
 MAINTAINERS                        |   7 +
 drivers/iio/temperature/Kconfig    |  12 +
 drivers/iio/temperature/Makefile   |   1 +
 drivers/iio/temperature/mlx90632.c | 802 +++++++++++++++++++++++++++++++++++++
 4 files changed, 822 insertions(+)
 create mode 100644 drivers/iio/temperature/mlx90632.c

Comments

Jonathan Cameron Dec. 2, 2017, 2:33 p.m. UTC | #1
On Wed, 29 Nov 2017 23:07:49 +0100
Crt Mori <cmo@melexis.com> wrote:

> Melexis has just released Infra Red temperature sensor MLX90632 used
> for contact-less temperature measurement. Driver provides basic
> functionality for reporting object (and ambient) temperature with
> support for object emissivity.
> 
> Signed-off-by: Crt Mori <cmo@melexis.com>

Various comments inline.

> ---
>  MAINTAINERS                        |   7 +
>  drivers/iio/temperature/Kconfig    |  12 +
>  drivers/iio/temperature/Makefile   |   1 +
>  drivers/iio/temperature/mlx90632.c | 802 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 822 insertions(+)
>  create mode 100644 drivers/iio/temperature/mlx90632.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2d3d750b19c0..81aec02b08b8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8690,6 +8690,13 @@ W:	http://www.melexis.com
>  S:	Supported
>  F:	drivers/iio/temperature/mlx90614.c
>  
> +MELEXIS MLX90632 DRIVER
> +M:	Crt Mori <cmo@melexis.com>
> +L:	linux-iio@vger.kernel.org
> +W:	http://www.melexis.com
> +S:	Supported
> +F:	drivers/iio/temperature/mlx90632.c
> +
>  MELFAS MIP4 TOUCHSCREEN DRIVER
>  M:	Sangwon Jee <jeesw@melfas.com>
>  W:	http://www.melfas.com
> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
> index 5378976d6d27..82e4a62745e2 100644
> --- a/drivers/iio/temperature/Kconfig
> +++ b/drivers/iio/temperature/Kconfig
> @@ -43,6 +43,18 @@ config MLX90614
>  	  This driver can also be built as a module. If so, the module will
>  	  be called mlx90614.
>  
> +config MLX90632
> +	tristate "MLX90632 contact-less infrared sensor with medical accuracy"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  If you say yes here you get support for the Melexis
> +	  MLX90632 contact-less infrared sensor with medical accuracy
> +	  connected with I2C.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called mlx90632.
> +
>  config TMP006
>  	tristate "TMP006 infrared thermopile sensor"
>  	depends on I2C
> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
> index ad1d668de546..44644fe01bc9 100644
> --- a/drivers/iio/temperature/Makefile
> +++ b/drivers/iio/temperature/Makefile
> @@ -5,6 +5,7 @@
>  obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
>  obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
>  obj-$(CONFIG_MLX90614) += mlx90614.o
> +obj-$(CONFIG_MLX90632) += mlx90632.o
>  obj-$(CONFIG_TMP006) += tmp006.o
>  obj-$(CONFIG_TMP007) += tmp007.o
>  obj-$(CONFIG_TSYS01) += tsys01.o
> diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
> new file mode 100644
> index 000000000000..05c7d943e504
> --- /dev/null
> +++ b/drivers/iio/temperature/mlx90632.c
> @@ -0,0 +1,802 @@
> +/*
> + * mlx90632.c - Melexis MLX90632 contactless IR temperature sensor
> + *
> + * Copyright (c) 2017 Melexis <cmo@melexis.com>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License.  See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * Driver for the Melexis MLX90632 I2C 16-bit IR thermopile sensor
> + */
> +#include <asm/byteorder.h>
Don't think this should ever be included in a driver.
What do you need it for?

> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/math64.h>
> +#include <linux/of.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/unaligned/be_byteshift.h>
why?

> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +/* Memory sections addresses */
> +#define MLX90632_ADDR_RAM	0x4000 /* Start address of ram */
> +#define MLX90632_ADDR_EEPROM	0x2480 /* Start address of user eeprom */
> +
> +/* EEPROM addresses - used at startup */
> +#define MLX90632_EE_CTRL	0x24d4 /* Control register initial value */
> +#define MLX90632_EE_I2C_ADDR	0x24d5 /* I2C address register initial value */
> +#define MLX90632_EE_VERSION	0x240b /* EEPROM version reg address */
> +#define MLX90632_EE_P_R		0x240c /* P_R calibration register 32bit */
> +#define MLX90632_EE_P_G		0x240e /* P_G calibration register 32bit */
> +#define MLX90632_EE_P_T		0x2410 /* P_T calibration register 32bit */
> +#define MLX90632_EE_P_O		0x2412 /* P_O calibration register 32bit */
> +#define MLX90632_EE_Aa		0x2414 /* Aa calibration register 32bit */
> +#define MLX90632_EE_Ab		0x2416 /* Ab calibration register 32bit */
> +#define MLX90632_EE_Ba		0x2418 /* Ba calibration register 32bit */
> +#define MLX90632_EE_Bb		0x241a /* Bb calibration register 32bit */
> +#define MLX90632_EE_Ca		0x241c /* Ca calibration register 32bit */
> +#define MLX90632_EE_Cb		0x241e /* Cb calibration register 32bit */
> +#define MLX90632_EE_Da		0x2420 /* Da calibration register 32bit */
> +#define MLX90632_EE_Db		0x2422 /* Db calibration register 32bit */
> +#define MLX90632_EE_Ea		0x2424 /* Ea calibration register 32bit */
> +#define MLX90632_EE_Eb		0x2426 /* Eb calibration register 32bit */
> +#define MLX90632_EE_Fa		0x2428 /* Fa calibration register 32bit */
> +#define MLX90632_EE_Fb		0x242a /* Fb calibration register 32bit */
> +#define MLX90632_EE_Ga		0x242c /* Ga calibration register 32bit */
> +
> +#define MLX90632_EE_Gb		0x242e /* Gb calibration register 16bit */
> +#define MLX90632_EE_Ka		0x242f /* Ka calibration register 16bit */
> +
> +#define MLX90632_EE_Ha		0x2481 /* Ha customer calib value reg 16bit */
> +#define MLX90632_EE_Hb		0x2482 /* Hb customer calib value reg 16bit */
> +
> +/* Register addresses - volatile */
> +#define MLX90632_REG_I2C_ADDR	0x3000 /* Chip I2C address register */
> +
> +/* Control register address - volatile */
> +#define MLX90632_REG_CONTROL	0x3001 /* Control Register address */
> +#define   MLX90632_CFG_PWR_MASK		GENMASK(2, 1) /* PowerMode Mask */
> +/* PowerModes statuses */
> +#define MLX90632_PWR_STATUS(ctrl_val) (ctrl_val << 1)
> +#define MLX90632_PWR_STATUS_HALT MLX90632_PWR_STATUS(0) /* hold */
> +#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step*/
> +#define MLX90632_PWR_STATUS_STEP MLX90632_PWR_STATUS(2) /* step */
> +#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous*/
> +
> +/* Device status register - volatile */
> +#define MLX90632_REG_STATUS	0x3fff /* Device status register */
> +#define   MLX90632_STAT_BUSY		BIT(10) /* Device busy indicator */
> +#define   MLX90632_STAT_EE_BUSY		BIT(9) /* EEPROM busy indicator */
> +#define   MLX90632_STAT_BRST		BIT(8) /* Brown out reset indicator */
> +#define   MLX90632_STAT_CYCLE_POS	GENMASK(6, 2) /* Data position */
> +#define   MLX90632_STAT_DATA_RDY	BIT(0) /* Data ready indicator */
> +
> +/* RAM_MEAS address-es for each channel */
> +#define MLX90632_RAM_1(meas_num)	(MLX90632_ADDR_RAM + 3 * meas_num)
> +#define MLX90632_RAM_2(meas_num)	(MLX90632_ADDR_RAM + 3 * meas_num + 1)
> +#define MLX90632_RAM_3(meas_num)	(MLX90632_ADDR_RAM + 3 * meas_num + 2)
> +
> +/* Magic constants */
> +#define MLX90632_EEPROM_VERSION	0xff05 /* EEPROM DSP version for constants */
> +#define MLX90632_ID_MEDICAL	0x01ff /* EEPROM Medical device id */
> +#define MLX90632_ID_CONSUMER	0x02ff /* EEPROM Consumer device id */
> +#define MLX90632_EEPROM_WRITE_KEY 0x554C /* EEPROM write key 0x55 and 0x4c */
> +#define MLX90632_RESET_CMD	0x0006 /* Reset sensor (address or global) */
> +#define MLX90632_REF_12		12LL /**< ResCtrlRef value of Ch 1 or Ch 2 */
> +#define MLX90632_REF_3		12LL /**< ResCtrlRef value of Channel 3 */
> +
> +#define TENTO3			1000LL
> +#define TENTO4			10000LL
> +#define TENTO5			100000LL
> +#define TENTO6			1000000LL
> +#define TENTO7			10000000LL
> +#define TENTO10			10000000000LL
> +#define TENTO12			1000000000000LL
Umm. The numbers describe the constants rather better than the defines ;)
Just use the numbers if you need them!

> +
> +struct mlx90632_data {
> +	struct i2c_client *client;
> +	struct mutex lock; /* Multiple reads for single measurement */
> +	struct regmap *regmap;
> +	u16 emissivity;
> +};
> +
> +static const struct regmap_range mlx90632_volatile_reg_range[] = {
> +	regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
> +	regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
> +	regmap_reg_range(MLX90632_RAM_1(0),
> +			 MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
> +};
> +
> +static const struct regmap_access_table mlx90632_volatile_regs_tbl = {
> +	.yes_ranges = mlx90632_volatile_reg_range,
> +	.n_yes_ranges = ARRAY_SIZE(mlx90632_volatile_reg_range),
> +};
> +
> +static const struct regmap_range mlx90632_read_reg_range[] = {
> +	regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
> +	regmap_reg_range(MLX90632_EE_CTRL, MLX90632_EE_I2C_ADDR),
> +	regmap_reg_range(MLX90632_EE_Ha, MLX90632_EE_Hb),
> +	regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
> +	regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
> +	regmap_reg_range(MLX90632_RAM_1(0),
> +			 MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
> +};
> +
> +static const struct regmap_access_table mlx90632_readable_regs_tbl = {
> +	.yes_ranges = mlx90632_read_reg_range,
> +	.n_yes_ranges = ARRAY_SIZE(mlx90632_read_reg_range),
> +};
> +
> +static const struct regmap_range mlx90632_no_write_reg_range[] = {
> +	regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
> +	regmap_reg_range(MLX90632_RAM_1(0),
> +			 MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
> +};
> +
> +static const struct regmap_access_table mlx90632_writeable_regs_tbl = {
> +	.no_ranges = mlx90632_no_write_reg_range,
> +	.n_no_ranges = ARRAY_SIZE(mlx90632_no_write_reg_range),
> +};
> +
> +static const struct regmap_config mlx90632_regmap = {
> +	.reg_bits = 16,
> +	.val_bits = 16,
> +
> +	.volatile_table = &mlx90632_volatile_regs_tbl,
> +	.rd_table = &mlx90632_readable_regs_tbl,
> +	.wr_table = &mlx90632_writeable_regs_tbl,
> +
> +	.use_single_rw = true,
> +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> +	.val_format_endian = REGMAP_ENDIAN_BIG,
> +	.cache_type = REGCACHE_RBTREE,
> +};
> +
> +static u64 mlx90632_int_sqrt(u64 x)
> +{
> +	u64 b, m, y = 0;
> +
> +	if (BITS_PER_LONG != 32)
> +		return int_sqrt(x);

needs a comment on why... 
Ideally propose a standard 64 bit routine if one is needed for
32 bit machines.

> +
> +	if (x <= 1)
> +		return x;
> +
> +	m = 1ULL << (64 - 2);
> +	while (m != 0) {
> +		b = y + m;
> +		y >>= 1;
> +
> +		if (x >= b) {
> +			x -= b;
> +			y += m;
> +		}
> +		m >>= 2;
> +	}
> +	return y;
> +}
> +
> +static s32 mlx90632_pwr_set_sleep_step(struct regmap *regmap)
> +{
> +	return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
> +				  MLX90632_CFG_PWR_MASK,
> +				  MLX90632_PWR_STATUS_SLEEP_STEP);
> +}
> +
> +static s32 mlx90632_pwr_set_step(struct regmap *regmap)
> +{
> +	return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
> +				  MLX90632_CFG_PWR_MASK,
> +				  MLX90632_PWR_STATUS_STEP);
> +}
> +
> +static s32 mlx90632_pwr_continuous(struct regmap *regmap)
> +{
> +	return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
> +				  MLX90632_CFG_PWR_MASK,
> +				  MLX90632_PWR_STATUS_CONTINUOUS);
> +}
> +
> +static int mlx90632_start_measurement(struct mlx90632_data *data)

Looks superficially to me like this is actually waiting for a reading
to complete rather than just starting it?  If so change the name
to reflect that.

> +{
> +	int ret, tries = 100;
> +	unsigned int reg_status;
> +
> +	ret = regmap_update_bits(data->regmap, MLX90632_REG_STATUS,
> +				 MLX90632_STAT_DATA_RDY, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	while (tries-- > 0) {
> +		ret = regmap_read(data->regmap, MLX90632_REG_STATUS,
> +				  &reg_status);
> +		if (ret < 0)
> +			return ret;
> +		if (reg_status & MLX90632_STAT_DATA_RDY)
> +			break;
> +		usleep_range(10000, 11000);
> +	}
> +
> +	if (tries < 0) {
> +		dev_err(&data->client->dev, "data not ready");
> +		return -ETIMEDOUT;
> +	}
> +
> +	return (reg_status & MLX90632_STAT_CYCLE_POS) >> 2;

This is a non obvious return value so I would suggest adding
some documentation to say what is going on here..

> +}
> +
> +static int mlx9032_channel_new_select(int ret, uint8_t *channel_new,
> +				      uint8_t *channel_old)

don't use ret as a name for a variable being passed in.  Rather
confusing!

> +{
> +	if (ret == 1) {
> +		*channel_new = 1;
> +		*channel_old = 2;
> +	} else if (ret == 2) {
> +		*channel_new = 2;
> +		*channel_old = 1;
> +	} else {
> +		return ret;
> +	}
> +	return 0;
Can't get here...

> +}
> +
> +static int mlx90632_read_ambient_raw(struct regmap *regmap,
> +				     s16 *ambient_new_raw, s16 *ambient_old_raw)
> +{
> +	int ret;
> +	unsigned int read_tmp;
> +
> +	ret = regmap_read(regmap, MLX90632_RAM_3(1), &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	*ambient_new_raw = (s16)read_tmp;
> +
> +	ret = regmap_read(regmap, MLX90632_RAM_3(2), &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	*ambient_old_raw = (s16)read_tmp;
> +
> +	return ret;
> +}
> +
> +static int mlx90632_read_object_raw(struct regmap *regmap,
> +				    int start_measurement_ret,
> +				    s16 *object_new_raw, s16 *object_old_raw)
> +{
> +	int ret;
> +	unsigned int read_tmp;
> +	s16 read;
> +	u8 channel = 0;
> +	u8 channel_old = 0;
> +
> +	ret = mlx90632_channel_new_select(start_measurement_ret, &channel,
> +					  &channel_old);
> +	if (ret != 0)
> +		return ret;
> +
> +	ret = regmap_read(regmap, MLX90632_RAM_2(channel), &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +
> +	read = (s16)read_tmp;
> +
> +	ret = regmap_read(regmap, MLX90632_RAM_1(channel), &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	*object_new_raw = (read + (s16)read_tmp) / 2;
> +
> +	ret = regmap_read(regmap, MLX90632_RAM_2(channel_old), &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	read = (s16)read_tmp;
> +
> +	ret = regmap_read(regmap, MLX90632_RAM_1(channel_old), &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	*object_old_raw = (read + (s16)read_tmp) / 2;
> +
> +	return ret;
> +}
> +
> +static int mlx90632_read_all_channel(struct mlx90632_data *data,
> +				     s16 *ambient_new_raw, s16 *ambient_old_raw,
> +				     s16 *object_new_raw, s16 *object_old_raw)
> +{
> +	s32 ret, tm_ret;
> +
> +	mutex_lock(&data->lock);
> +	tm_ret = mlx90632_start_measurement(data);
> +	if (tm_ret >= 0) {
> +		ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
> +						ambient_old_raw);
> +		if (ret >= 0) {
> +			ret = mlx90632_read_object_raw(data->regmap, tm_ret,
> +						       object_new_raw,
> +						       object_old_raw);
> +		}
> +	} else {
> +		ret = tm_ret;
> +	}
Use something cleaner like
	mutex_lock(&data->lock);
	ret = mlx90632_start_measurement(data);
	if (ret < 0)
		goto unlock;
	ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
					ambient_old_raw);
	if (ret < 0)
		goto unlock;

	ret = mlx90632_read_object_raw(data->regmap, tm_ret,
				       object_new_raw,
				       object_old_raw);
unlock:
> +	mutex_unlock(&data->lock);
> +	return ret;
> +}
> +
> +static int mlx90632_read_ee_register(struct regmap *regmap, u16 reg_lsb,
> +				     s32 *reg_value)
> +{
> +	s32 ret;
> +	unsigned int read;
> +	__le32 value;
> +
> +	ret = regmap_read(regmap, reg_lsb, &read);
> +	if (ret < 0)
> +		return ret;
> +
> +	value = cpu_to_le32(read);

Why would you be converting to le32 to then do
calculations in here using it at cpu endianness?
(guessing you want le32_to_cpu..)

hmm isn't any relevant endian conversion wrapped up in regmap
anyway?

> +
> +	ret = regmap_read(regmap, reg_lsb + 1, &read);
> +	if (ret < 0)
> +		return ret;
> +
> +	value = (cpu_to_le32(read) << 16) | (value & 0xffff);
> +
> +	*reg_value = le32_to_cpu(value);
> +	return 0;
> +}
> +
> +static s64 mlx90632_preprocess_temp_amb(s16 ambient_new_raw,
> +					s16 ambient_old_raw, s16 Gb)
> +{
> +	s64 VR_Ta, kGb, tmp;
> +
> +	kGb = ((s64)Gb * TENTO3) >> 10ULL;
> +	VR_Ta = (s64)ambient_old_raw * TENTO6 +
> +		kGb * div64_s64(((s64)ambient_new_raw * TENTO3),
> +			(MLX90632_REF_3));
> +	tmp = div64_s64(
> +			 div64_s64(((s64)ambient_new_raw * TENTO12),
> +				   (MLX90632_REF_3)), VR_Ta);
> +	return div64_s64(tmp << 19ULL, TENTO3);
> +}
> +
> +static s64 mlx90632_preprocess_temp_obj(s16 object_new_raw, s16 object_old_raw,
> +					s16 ambient_new_raw,
> +					s16 ambient_old_raw, s16 Ka)
> +{
> +	s64 VR_IR, kKa, tmp;
> +
> +	kKa = ((s64)Ka * TENTO3) >> 10ULL;
> +	VR_IR = (s64)ambient_old_raw * TENTO6 +
> +		kKa * div64_s64(((s64)ambient_new_raw * TENTO3),
> +			(MLX90632_REF_3));
> +	tmp = div64_s64(
> +			div64_s64(((s64)((object_new_raw + object_old_raw) / 2)
> +				   * TENTO12), (MLX90632_REF_12)), VR_IR);
> +	return div64_s64(tmp << 19ULL), TENTO3);
> +}
> +
> +static s32 mlx90632_calc_temp_ambient(s16 ambient_new_raw, s16 ambient_old_raw,
> +				      s32 P_T, s32 P_R, s32 P_G, s32 P_O,
> +				      s16 Gb)
> +{
> +	s64 Asub, Bsub, Ablock, Bblock, Cblock, AMB, sum;
> +
> +	AMB = mlx90632_preprocess_temp_amb(ambient_new_raw, ambient_old_raw,
> +					   Gb);
> +	Asub = ((s64)P_T * TENTO10) >> 44ULL;
> +	Bsub = AMB - (((s64)P_R * TENTO3) >> 8ULL);
> +	Ablock = Asub * (Bsub * Bsub);
> +	Bblock = (div64_s64(Bsub * TENTO7, P_G)) << 20ULL;
> +	Cblock = ((s64)P_O * TENTO10) >> 8ULL;
> +
> +	sum = div64_s64(Ablock, TENTO6) + Bblock + Cblock;
> +
> +	return div64_s64(sum, TENTO7);
> +}
> +
> +static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
> +					       s64 TAdut, s32 Fa, s32 Fb,
> +					       s32 Ga, s16 Ha, s16 Hb,
> +					       u16 emissivity)
> +{
> +	s64 calcedKsTO, calcedKsTA, ir_Alpha, TAdut4, Alpha_corr;
> +	s64 Ha_customer, Hb_customer;
> +
> +	Ha_customer = ((s64)Ha * TENTO6) >> 14ULL;
> +	Hb_customer = ((s64)Hb * 100) >> 10ULL;
> +
> +	calcedKsTO = ((s64)((s64)Ga * (prev_object_temp - 25 * TENTO3)
> +			     * TENTO3)) >> 36LL;
> +	calcedKsTA = ((s64)(Fb * (TAdut - 25 * TENTO6))) >> 36LL;
> +	Alpha_corr = div64_s64((((s64)(Fa * TENTO10) >> 46LL) * Ha_customer),
> +			       TENTO3);
> +	Alpha_corr *= ((s64)(1 * TENTO6 + calcedKsTO + calcedKsTA));
> +	Alpha_corr = emissivity * div64_s64(Alpha_corr, TENTO5);
> +	Alpha_corr = div64_s64(Alpha_corr, TENTO3);
> +	ir_Alpha = div64_s64((s64)object * TENTO7, Alpha_corr);
> +	TAdut4 = (div64_s64(TAdut, TENTO4) + 27315) *
> +		(div64_s64(TAdut, TENTO4) + 27315) *
> +		(div64_s64(TAdut, TENTO4)  + 27315) *
> +		(div64_s64(TAdut, TENTO4) + 27315);
> +
> +	return (mlx90632_int_sqrt(
> +			 mlx90632_int_sqrt(ir_Alpha * TENTO12 + TAdut4)
> +			) - 27315 - Hb_customer) * 10;
> +}
> +
> +static s32 mlx90632_calc_temp_object(s64 object, s64 ambient, s32 Ea, s32 Eb,
> +				     s32 Fa, s32 Fb, s32 Ga, s16 Ha, s16 Hb,
> +				     u16 tmp_emi)
> +{
> +	s64 kTA, kTA0, TAdut;
> +	s64 temp = 25000;
> +	s8 i;
> +
> +	kTA = (Ea * TENTO3) >> 16LL;
> +	kTA0 = (Eb * TENTO3) >> 8LL;
> +	TAdut = div64_s64(((ambient - kTA0) * TENTO6), kTA) + 25 * TENTO6;
> +
> +	for (i = 0; i < 5; ++i) {
comment on why iterations are needed would be good here.
> +		temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut,
> +							   Fa, Fb, Ga, Ha, Hb,
> +							   tmp_emi);
> +	}
> +	return temp;
> +}
> +
> +static int mlx90632_calc_object_dsp105(struct mlx90632_data *data, int *val)
> +{
> +	s32 ret;
> +	s32 Ea, Eb, Fa, Fb, Ga;
> +	unsigned int read_tmp;
> +	s16 Ha, Hb, Gb, Ka;
> +	s16 ambient_new_raw, ambient_old_raw, object_new_raw, object_old_raw;
> +	s64 object, ambient;
> +
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ea, &Ea);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Eb, &Eb);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fa, &Fa);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fb, &Fb);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ga, &Ga);
> +	if (ret < 0)
> +		return ret;
> +	ret = regmap_read(data->regmap, MLX90632_EE_Ha, &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	Ha = (s16)read_tmp;
> +	ret = regmap_read(data->regmap, MLX90632_EE_Hb, &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	Hb = (s16)read_tmp;
> +	ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	Gb = (s16)read_tmp;
> +	ret = regmap_read(data->regmap, MLX90632_EE_Ka, &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	Ka = (s16)read_tmp;
> +
> +	ret = mlx90632_read_all_channel(data,
> +					&ambient_new_raw, &ambient_old_raw,
> +					&object_new_raw, &object_old_raw);
> +	if (ret < 0)
> +		return ret;
> +
> +	ambient = mlx90632_preprocess_temp_amb(ambient_new_raw,
> +					       ambient_old_raw, Gb);
> +	object = mlx90632_preprocess_temp_obj(object_new_raw,
> +					      object_old_raw,
> +					      ambient_new_raw,
> +					      ambient_old_raw, Ka);
> +
> +	*val = mlx90632_calc_temp_object(object, ambient, Ea, Eb, Fa, Fb, Ga,
> +					 Ha, Hb, data->emissivity);
> +	return 0;
> +}
> +
> +static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
> +{
> +	s32 ret;
> +	unsigned int read_tmp;
> +	s32 PT, PR, PG, PO;
> +	s16 Gb;
> +	s16 ambient_new_raw, ambient_old_raw;
> +
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_R, &PR);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_G, &PG);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_T, &PT);
> +	if (ret < 0)
> +		return ret;
> +	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_O, &PO);
> +	if (ret < 0)
> +		return ret;
> +	ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
> +	if (ret < 0)
> +		return ret;
> +	Gb = (s16)read_tmp;
> +
> +	ret = mlx90632_read_ambient_raw(data->regmap, &ambient_new_raw,
> +					&ambient_old_raw);
> +	*val = mlx90632_calc_temp_ambient(ambient_new_raw, ambient_old_raw,
> +					  PT, PR, PG, PO, Gb);
> +	return ret;
> +}
> +
> +static int mlx90632_read_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *channel, int *val,
> +			     int *val2, long mask)
> +{
> +	struct mlx90632_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_PROCESSED:
> +		switch (channel->channel2) {
> +		case IIO_MOD_TEMP_AMBIENT:
> +			ret = mlx90632_calc_ambient_dsp105(data, val);
> +			if (ret < 0)
> +				return ret;
> +			return IIO_VAL_INT;
> +		case IIO_MOD_TEMP_OBJECT:
> +			ret = mlx90632_calc_object_dsp105(data, val);
> +			if (ret < 0)
> +				return ret;
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_CALIBEMISSIVITY:
> +		if (data->emissivity == 1000) {
> +			*val = 1;
> +			*val2 = 0;
> +		} else {
> +			*val = 0;
> +			*val2 = data->emissivity;
Odd given you are reporting as int + nano
this goes from 1.0 to 0.000000999 in one step?
Seems unlikely..  If it is true then a comment
is needed.

The write is int + micro but this would still be wrong
without a factor of 1000.

> +		}
> +		return IIO_VAL_INT_PLUS_NANO;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int mlx90632_write_raw(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *channel, int val,
> +			      int val2, long mask)
> +{
> +	struct mlx90632_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_CALIBEMISSIVITY:
> +		if (val < 0 || val2 < 0 || val > 1 ||
> +		    (val == 1 && val2 != 0))

I'd add a comment describing what this is doing.  I think it
is checking for 0-1.0 inclusive?

> +			return -EINVAL;
> +		data->emissivity = val * 1000 + val2 / 1000;
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_chan_spec mlx90632_channels[] = {
> +	{
> +		.type = IIO_TEMP,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_TEMP_AMBIENT,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +	},
> +	{
> +		.type = IIO_TEMP,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_TEMP_OBJECT,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +			BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
> +	},
> +};
> +
> +static const struct iio_info mlx90632_info = {
> +	.read_raw = mlx90632_read_raw,
> +	.write_raw = mlx90632_write_raw,
> +};
> +
> +#ifdef CONFIG_PM
> +static int mlx90632_sleep(struct mlx90632_data *data)
> +{
> +	dev_dbg(&data->client->dev, "Requesting sleep");
> +	return mlx90632_pwr_set_sleep_step(data->regmap);
> +}
> +
> +static int mlx90632_wakeup(struct mlx90632_data *data)
> +{
> +	dev_dbg(&data->client->dev, "Requesting wake-up");
> +	return mlx90632_pwr_continuous(data->regmap);
> +}
> +#endif
> +
> +static int mlx90632_probe(struct i2c_client *client,
> +			  const struct i2c_device_id *id)
> +{
> +	struct iio_dev *indio_dev;
> +	struct mlx90632_data *mlx90632;
> +	struct regmap *regmap;
> +	int ret;
> +	unsigned int read;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*mlx90632));
> +	if (!indio_dev) {
> +		dev_err(&client->dev, "Failed to allocate device");
> +		return -ENOMEM;
> +	}
> +
> +	regmap = devm_regmap_init_i2c(client, &mlx90632_regmap);
> +	if (IS_ERR(regmap)) {
> +		ret = PTR_ERR(regmap);
> +		dev_err(&client->dev, "Failed to allocate regmap: %d\n", ret);
> +		return ret;
> +	}
> +
> +	mlx90632 = iio_priv(indio_dev);
> +	i2c_set_clientdata(client, indio_dev);
> +	mlx90632->client = client;
> +	mlx90632->regmap = regmap;
> +
> +	mutex_init(&mlx90632->lock);
> +	mlx90632_wakeup(mlx90632);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->name = id->name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &mlx90632_info;
> +	indio_dev->channels = mlx90632_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(mlx90632_channels);
> +
> +	ret = regmap_read(mlx90632->regmap, MLX90632_EE_VERSION, &read);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "read of version failed: %d\n", ret);
> +		return ret;
> +	}
> +	if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_MEDICAL)) {

This is odd.  Why the bitwise and of what look to be two different things entirely?

> +		dev_dbg(&client->dev,
> +			"Detected Medical EEPROM calibration %x", read);
> +	} else if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_CONSUMER)) {
> +		dev_dbg(&client->dev,
> +			"Detected Consumer EEPROM calibration %x", read);
> +	} else {
> +		dev_err(&client->dev,
> +			"Chip EEPROM version mismatch %x (expected %x)",
> +			read, MLX90632_EEPROM_VERSION);
> +		return -EPROTONOSUPPORT;
> +	}
> +
> +	mlx90632->emissivity = 1000;
> +
> +	return devm_iio_device_register(&client->dev, indio_dev);

Don't use devm version.  You are (correctly) manually unwinding
this in the remove (as you have pm to deal with after removing the
interfaces).  This will result in a double free I think...
return iio_device_register is the way to go.

I'm a bit confused that you don't seem to set up runtime pm anywhere...
I would assume we would be looking at autosuspend for a device
like this but it isn't enabled..

> +}
> +
> +static int mlx90632_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct mlx90632_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	pm_runtime_disable(&client->dev);
> +	if (!pm_runtime_status_suspended(&client->dev))
> +		mlx90632_sleep(data);
> +	pm_runtime_set_suspended(&client->dev);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id mlx90632_id[] = {
> +	{ "mlx90632", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, mlx90632_id);
> +
> +static const struct of_device_id mlx90632_of_match[] = {
> +	{ .compatible = "melexis,mlx90632" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, mlx90632_of_match);
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mlx90632_pm_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct mlx90632_data *data = iio_priv(indio_dev);
> +
> +	if (pm_runtime_active(dev))
> +		return mlx90632_sleep(data);

I'm a little confused as to why, if the device is powered
up fully and a suspend comes in we have to do less than we do
in runtime pm case.

Am I missing something?

> +
> +	return 0;
> +}
> +
> +static int mlx90632_pm_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct mlx90632_data *data = iio_priv(indio_dev);
> +	int err;
> +
> +	err = mlx90632_wakeup(data);
> +	if (err < 0)
> +		return err;
> +
> +	pm_runtime_disable(dev);
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +
> +	return 0;
> +}
> +#endif
> +
> +#ifdef CONFIG_PM
> +static int mlx90632_pm_runtime_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
> +
> +	regcache_sync(mlx90632->regmap);
> +
> +	return mlx90632_sleep(mlx90632);
> +}
> +
> +static int mlx90632_pm_runtime_resume(struct device *dev)
> +{
> +	s32 ret;
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
> +
> +	regcache_mark_dirty(mlx90632->regmap);
> +	regcache_cache_only(mlx90632->regmap, false);
> +	ret = regcache_sync(mlx90632->regmap);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to sync regmap registers: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return mlx90632_wakeup(mlx90632);
> +}
> +#endif
> +
> +static const struct dev_pm_ops mlx90632_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(mlx90632_pm_suspend, mlx90632_pm_resume)
> +	SET_RUNTIME_PM_OPS(mlx90632_pm_runtime_suspend,
> +			   mlx90632_pm_runtime_resume, NULL)
> +};
> +
> +static struct i2c_driver mlx90632_driver = {
> +	.driver = {
> +		.name	= "mlx90632",
> +		.of_match_table = mlx90632_of_match,
> +		.pm	= &mlx90632_pm_ops,
> +	},
> +	.probe = mlx90632_probe,
> +	.remove = mlx90632_remove,
> +	.id_table = mlx90632_id,
> +};
> +module_i2c_driver(mlx90632_driver);
> +
> +MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
> +MODULE_DESCRIPTION("Melexis MLX90632 contactless Infra Red temperature sensor driver");
> +MODULE_LICENSE("GPL v2");

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Crt Mori Dec. 2, 2017, 8:30 p.m. UTC | #2
Hi Jonathan,
Definitely did not think there will be so many comments inside, but I
expected few of them indeed.

See my replies inside.

On 2 December 2017 at 15:33, Jonathan Cameron <jic23@kernel.org> wrote:
> On Wed, 29 Nov 2017 23:07:49 +0100
> Crt Mori <cmo@melexis.com> wrote:
>
>> Melexis has just released Infra Red temperature sensor MLX90632 used
>> for contact-less temperature measurement. Driver provides basic
>> functionality for reporting object (and ambient) temperature with
>> support for object emissivity.
>>
>> Signed-off-by: Crt Mori <cmo@melexis.com>
>
> Various comments inline.
>
>> ---
>>  MAINTAINERS                        |   7 +
>>  drivers/iio/temperature/Kconfig    |  12 +
>>  drivers/iio/temperature/Makefile   |   1 +
>>  drivers/iio/temperature/mlx90632.c | 802 +++++++++++++++++++++++++++++++++++++
>>  4 files changed, 822 insertions(+)
>>  create mode 100644 drivers/iio/temperature/mlx90632.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 2d3d750b19c0..81aec02b08b8 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -8690,6 +8690,13 @@ W:     http://www.melexis.com
>>  S:   Supported
>>  F:   drivers/iio/temperature/mlx90614.c
>>
>> +MELEXIS MLX90632 DRIVER
>> +M:   Crt Mori <cmo@melexis.com>
>> +L:   linux-iio@vger.kernel.org
>> +W:   http://www.melexis.com
>> +S:   Supported
>> +F:   drivers/iio/temperature/mlx90632.c
>> +
>>  MELFAS MIP4 TOUCHSCREEN DRIVER
>>  M:   Sangwon Jee <jeesw@melfas.com>
>>  W:   http://www.melfas.com
>> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
>> index 5378976d6d27..82e4a62745e2 100644
>> --- a/drivers/iio/temperature/Kconfig
>> +++ b/drivers/iio/temperature/Kconfig
>> @@ -43,6 +43,18 @@ config MLX90614
>>         This driver can also be built as a module. If so, the module will
>>         be called mlx90614.
>>
>> +config MLX90632
>> +     tristate "MLX90632 contact-less infrared sensor with medical accuracy"
>> +     depends on I2C
>> +     select REGMAP_I2C
>> +     help
>> +       If you say yes here you get support for the Melexis
>> +       MLX90632 contact-less infrared sensor with medical accuracy
>> +       connected with I2C.
>> +
>> +       This driver can also be built as a module. If so, the module will
>> +       be called mlx90632.
>> +
>>  config TMP006
>>       tristate "TMP006 infrared thermopile sensor"
>>       depends on I2C
>> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
>> index ad1d668de546..44644fe01bc9 100644
>> --- a/drivers/iio/temperature/Makefile
>> +++ b/drivers/iio/temperature/Makefile
>> @@ -5,6 +5,7 @@
>>  obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
>>  obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
>>  obj-$(CONFIG_MLX90614) += mlx90614.o
>> +obj-$(CONFIG_MLX90632) += mlx90632.o
>>  obj-$(CONFIG_TMP006) += tmp006.o
>>  obj-$(CONFIG_TMP007) += tmp007.o
>>  obj-$(CONFIG_TSYS01) += tsys01.o
>> diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
>> new file mode 100644
>> index 000000000000..05c7d943e504
>> --- /dev/null
>> +++ b/drivers/iio/temperature/mlx90632.c
>> @@ -0,0 +1,802 @@
>> +/*
>> + * mlx90632.c - Melexis MLX90632 contactless IR temperature sensor
>> + *
>> + * Copyright (c) 2017 Melexis <cmo@melexis.com>
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License.  See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * Driver for the Melexis MLX90632 I2C 16-bit IR thermopile sensor
>> + */
>> +#include <asm/byteorder.h>
> Don't think this should ever be included in a driver.
> What do you need it for?
>
>> +#include <linux/delay.h>
>> +#include <linux/err.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/i2c.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/math64.h>
>> +#include <linux/of.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/regmap.h>
>> +#include <linux/unaligned/be_byteshift.h>
> why?
>
>> +
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +
>> +/* Memory sections addresses */
>> +#define MLX90632_ADDR_RAM    0x4000 /* Start address of ram */
>> +#define MLX90632_ADDR_EEPROM 0x2480 /* Start address of user eeprom */
>> +
>> +/* EEPROM addresses - used at startup */
>> +#define MLX90632_EE_CTRL     0x24d4 /* Control register initial value */
>> +#define MLX90632_EE_I2C_ADDR 0x24d5 /* I2C address register initial value */
>> +#define MLX90632_EE_VERSION  0x240b /* EEPROM version reg address */
>> +#define MLX90632_EE_P_R              0x240c /* P_R calibration register 32bit */
>> +#define MLX90632_EE_P_G              0x240e /* P_G calibration register 32bit */
>> +#define MLX90632_EE_P_T              0x2410 /* P_T calibration register 32bit */
>> +#define MLX90632_EE_P_O              0x2412 /* P_O calibration register 32bit */
>> +#define MLX90632_EE_Aa               0x2414 /* Aa calibration register 32bit */
>> +#define MLX90632_EE_Ab               0x2416 /* Ab calibration register 32bit */
>> +#define MLX90632_EE_Ba               0x2418 /* Ba calibration register 32bit */
>> +#define MLX90632_EE_Bb               0x241a /* Bb calibration register 32bit */
>> +#define MLX90632_EE_Ca               0x241c /* Ca calibration register 32bit */
>> +#define MLX90632_EE_Cb               0x241e /* Cb calibration register 32bit */
>> +#define MLX90632_EE_Da               0x2420 /* Da calibration register 32bit */
>> +#define MLX90632_EE_Db               0x2422 /* Db calibration register 32bit */
>> +#define MLX90632_EE_Ea               0x2424 /* Ea calibration register 32bit */
>> +#define MLX90632_EE_Eb               0x2426 /* Eb calibration register 32bit */
>> +#define MLX90632_EE_Fa               0x2428 /* Fa calibration register 32bit */
>> +#define MLX90632_EE_Fb               0x242a /* Fb calibration register 32bit */
>> +#define MLX90632_EE_Ga               0x242c /* Ga calibration register 32bit */
>> +
>> +#define MLX90632_EE_Gb               0x242e /* Gb calibration register 16bit */
>> +#define MLX90632_EE_Ka               0x242f /* Ka calibration register 16bit */
>> +
>> +#define MLX90632_EE_Ha               0x2481 /* Ha customer calib value reg 16bit */
>> +#define MLX90632_EE_Hb               0x2482 /* Hb customer calib value reg 16bit */
>> +
>> +/* Register addresses - volatile */
>> +#define MLX90632_REG_I2C_ADDR        0x3000 /* Chip I2C address register */
>> +
>> +/* Control register address - volatile */
>> +#define MLX90632_REG_CONTROL 0x3001 /* Control Register address */
>> +#define   MLX90632_CFG_PWR_MASK              GENMASK(2, 1) /* PowerMode Mask */
>> +/* PowerModes statuses */
>> +#define MLX90632_PWR_STATUS(ctrl_val) (ctrl_val << 1)
>> +#define MLX90632_PWR_STATUS_HALT MLX90632_PWR_STATUS(0) /* hold */
>> +#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step*/
>> +#define MLX90632_PWR_STATUS_STEP MLX90632_PWR_STATUS(2) /* step */
>> +#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous*/
>> +
>> +/* Device status register - volatile */
>> +#define MLX90632_REG_STATUS  0x3fff /* Device status register */
>> +#define   MLX90632_STAT_BUSY         BIT(10) /* Device busy indicator */
>> +#define   MLX90632_STAT_EE_BUSY              BIT(9) /* EEPROM busy indicator */
>> +#define   MLX90632_STAT_BRST         BIT(8) /* Brown out reset indicator */
>> +#define   MLX90632_STAT_CYCLE_POS    GENMASK(6, 2) /* Data position */
>> +#define   MLX90632_STAT_DATA_RDY     BIT(0) /* Data ready indicator */
>> +
>> +/* RAM_MEAS address-es for each channel */
>> +#define MLX90632_RAM_1(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num)
>> +#define MLX90632_RAM_2(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num + 1)
>> +#define MLX90632_RAM_3(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num + 2)
>> +
>> +/* Magic constants */
>> +#define MLX90632_EEPROM_VERSION      0xff05 /* EEPROM DSP version for constants */
>> +#define MLX90632_ID_MEDICAL  0x01ff /* EEPROM Medical device id */
>> +#define MLX90632_ID_CONSUMER 0x02ff /* EEPROM Consumer device id */
>> +#define MLX90632_EEPROM_WRITE_KEY 0x554C /* EEPROM write key 0x55 and 0x4c */
>> +#define MLX90632_RESET_CMD   0x0006 /* Reset sensor (address or global) */
>> +#define MLX90632_REF_12              12LL /**< ResCtrlRef value of Ch 1 or Ch 2 */
>> +#define MLX90632_REF_3               12LL /**< ResCtrlRef value of Channel 3 */
>> +
>> +#define TENTO3                       1000LL
>> +#define TENTO4                       10000LL
>> +#define TENTO5                       100000LL
>> +#define TENTO6                       1000000LL
>> +#define TENTO7                       10000000LL
>> +#define TENTO10                      10000000000LL
>> +#define TENTO12                      1000000000000LL
> Umm. The numbers describe the constants rather better than the defines ;)
> Just use the numbers if you need them!
>

This is way shorter (line length) and more readable in my opinion.
Also writing 12 times 0 is error prone :D

>> +
>> +struct mlx90632_data {
>> +     struct i2c_client *client;
>> +     struct mutex lock; /* Multiple reads for single measurement */
>> +     struct regmap *regmap;
>> +     u16 emissivity;
>> +};
>> +
>> +static const struct regmap_range mlx90632_volatile_reg_range[] = {
>> +     regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
>> +     regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
>> +     regmap_reg_range(MLX90632_RAM_1(0),
>> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
>> +};
>> +
>> +static const struct regmap_access_table mlx90632_volatile_regs_tbl = {
>> +     .yes_ranges = mlx90632_volatile_reg_range,
>> +     .n_yes_ranges = ARRAY_SIZE(mlx90632_volatile_reg_range),
>> +};
>> +
>> +static const struct regmap_range mlx90632_read_reg_range[] = {
>> +     regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
>> +     regmap_reg_range(MLX90632_EE_CTRL, MLX90632_EE_I2C_ADDR),
>> +     regmap_reg_range(MLX90632_EE_Ha, MLX90632_EE_Hb),
>> +     regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
>> +     regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
>> +     regmap_reg_range(MLX90632_RAM_1(0),
>> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
>> +};
>> +
>> +static const struct regmap_access_table mlx90632_readable_regs_tbl = {
>> +     .yes_ranges = mlx90632_read_reg_range,
>> +     .n_yes_ranges = ARRAY_SIZE(mlx90632_read_reg_range),
>> +};
>> +
>> +static const struct regmap_range mlx90632_no_write_reg_range[] = {
>> +     regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
>> +     regmap_reg_range(MLX90632_RAM_1(0),
>> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
>> +};
>> +
>> +static const struct regmap_access_table mlx90632_writeable_regs_tbl = {
>> +     .no_ranges = mlx90632_no_write_reg_range,
>> +     .n_no_ranges = ARRAY_SIZE(mlx90632_no_write_reg_range),
>> +};
>> +
>> +static const struct regmap_config mlx90632_regmap = {
>> +     .reg_bits = 16,
>> +     .val_bits = 16,
>> +
>> +     .volatile_table = &mlx90632_volatile_regs_tbl,
>> +     .rd_table = &mlx90632_readable_regs_tbl,
>> +     .wr_table = &mlx90632_writeable_regs_tbl,
>> +
>> +     .use_single_rw = true,
>> +     .reg_format_endian = REGMAP_ENDIAN_BIG,
>> +     .val_format_endian = REGMAP_ENDIAN_BIG,
>> +     .cache_type = REGCACHE_RBTREE,
>> +};
>> +
>> +static u64 mlx90632_int_sqrt(u64 x)
>> +{
>> +     u64 b, m, y = 0;
>> +
>> +     if (BITS_PER_LONG != 32)
>> +             return int_sqrt(x);
>
> needs a comment on why...
> Ideally propose a standard 64 bit routine if one is needed for
> 32 bit machines.
>

Problem is that int_sqrt is not strongly typed. That means 64 bit
number gets truncated to 32bit on 32bit machine as you mentioned
and that caused quite many headaches in my testing (worked on
mobile phone, but not on beaglebone black).  This solution is just
stronger typing of int_sqrt function.

If you think I should put it onto math.h as a patch I can try it.

>> +
>> +     if (x <= 1)
>> +             return x;
>> +
>> +     m = 1ULL << (64 - 2);
>> +     while (m != 0) {
>> +             b = y + m;
>> +             y >>= 1;
>> +
>> +             if (x >= b) {
>> +                     x -= b;
>> +                     y += m;
>> +             }
>> +             m >>= 2;
>> +     }
>> +     return y;
>> +}
>> +
>> +static s32 mlx90632_pwr_set_sleep_step(struct regmap *regmap)
>> +{
>> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
>> +                               MLX90632_CFG_PWR_MASK,
>> +                               MLX90632_PWR_STATUS_SLEEP_STEP);
>> +}
>> +
>> +static s32 mlx90632_pwr_set_step(struct regmap *regmap)
>> +{
>> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
>> +                               MLX90632_CFG_PWR_MASK,
>> +                               MLX90632_PWR_STATUS_STEP);
>> +}
>> +
>> +static s32 mlx90632_pwr_continuous(struct regmap *regmap)
>> +{
>> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
>> +                               MLX90632_CFG_PWR_MASK,
>> +                               MLX90632_PWR_STATUS_CONTINUOUS);
>> +}
>> +
>> +static int mlx90632_start_measurement(struct mlx90632_data *data)
>
> Looks superficially to me like this is actually waiting for a reading
> to complete rather than just starting it?  If so change the name
> to reflect that.
>

ok

>> +{
>> +     int ret, tries = 100;
>> +     unsigned int reg_status;
>> +
>> +     ret = regmap_update_bits(data->regmap, MLX90632_REG_STATUS,
>> +                              MLX90632_STAT_DATA_RDY, 0);
>> +     if (ret < 0)
>> +             return ret;
>> +
>> +     while (tries-- > 0) {
>> +             ret = regmap_read(data->regmap, MLX90632_REG_STATUS,
>> +                               &reg_status);
>> +             if (ret < 0)
>> +                     return ret;
>> +             if (reg_status & MLX90632_STAT_DATA_RDY)
>> +                     break;
>> +             usleep_range(10000, 11000);
>> +     }
>> +
>> +     if (tries < 0) {
>> +             dev_err(&data->client->dev, "data not ready");
>> +             return -ETIMEDOUT;
>> +     }
>> +
>> +     return (reg_status & MLX90632_STAT_CYCLE_POS) >> 2;
>
> This is a non obvious return value so I would suggest adding
> some documentation to say what is going on here..
>

Yes, it is indeed.

>> +}
>> +
>> +static int mlx9032_channel_new_select(int ret, uint8_t *channel_new,
>> +                                   uint8_t *channel_old)
>
> don't use ret as a name for a variable being passed in.  Rather
> confusing!
>

OK. I think I should just copy setting of channel_old and new in the
only spot it is used.

>> +{
>> +     if (ret == 1) {
>> +             *channel_new = 1;
>> +             *channel_old = 2;
>> +     } else if (ret == 2) {
>> +             *channel_new = 2;
>> +             *channel_old = 1;
>> +     } else {
>> +             return ret;
>> +     }
>> +     return 0;
> Can't get here...
>

Not true. You get here in every example other than else where channel_new
and channel_old are successfully set. but I agree there is a bug in case ret=0
when it will return 0, but it will not set channels.

>> +}
>> +
>> +static int mlx90632_read_ambient_raw(struct regmap *regmap,
>> +                                  s16 *ambient_new_raw, s16 *ambient_old_raw)
>> +{
>> +     int ret;
>> +     unsigned int read_tmp;
>> +
>> +     ret = regmap_read(regmap, MLX90632_RAM_3(1), &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     *ambient_new_raw = (s16)read_tmp;
>> +
>> +     ret = regmap_read(regmap, MLX90632_RAM_3(2), &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     *ambient_old_raw = (s16)read_tmp;
>> +
>> +     return ret;
>> +}
>> +
>> +static int mlx90632_read_object_raw(struct regmap *regmap,
>> +                                 int start_measurement_ret,
>> +                                 s16 *object_new_raw, s16 *object_old_raw)
>> +{
>> +     int ret;
>> +     unsigned int read_tmp;
>> +     s16 read;
>> +     u8 channel = 0;
>> +     u8 channel_old = 0;
>> +
>> +     ret = mlx90632_channel_new_select(start_measurement_ret, &channel,
>> +                                       &channel_old);
>> +     if (ret != 0)
>> +             return ret;
>> +
>> +     ret = regmap_read(regmap, MLX90632_RAM_2(channel), &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +
>> +     read = (s16)read_tmp;
>> +
>> +     ret = regmap_read(regmap, MLX90632_RAM_1(channel), &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     *object_new_raw = (read + (s16)read_tmp) / 2;
>> +
>> +     ret = regmap_read(regmap, MLX90632_RAM_2(channel_old), &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     read = (s16)read_tmp;
>> +
>> +     ret = regmap_read(regmap, MLX90632_RAM_1(channel_old), &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     *object_old_raw = (read + (s16)read_tmp) / 2;
>> +
>> +     return ret;
>> +}
>> +
>> +static int mlx90632_read_all_channel(struct mlx90632_data *data,
>> +                                  s16 *ambient_new_raw, s16 *ambient_old_raw,
>> +                                  s16 *object_new_raw, s16 *object_old_raw)
>> +{
>> +     s32 ret, tm_ret;
>> +
>> +     mutex_lock(&data->lock);
>> +     tm_ret = mlx90632_start_measurement(data);
>> +     if (tm_ret >= 0) {
>> +             ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
>> +                                             ambient_old_raw);
>> +             if (ret >= 0) {
>> +                     ret = mlx90632_read_object_raw(data->regmap, tm_ret,
>> +                                                    object_new_raw,
>> +                                                    object_old_raw);
>> +             }
>> +     } else {
>> +             ret = tm_ret;
>> +     }
> Use something cleaner like
>         mutex_lock(&data->lock);
>         ret = mlx90632_start_measurement(data);
>         if (ret < 0)
>                 goto unlock;
>         ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
>                                         ambient_old_raw);
>         if (ret < 0)
>                 goto unlock;
>
>         ret = mlx90632_read_object_raw(data->regmap, tm_ret,
>                                        object_new_raw,
>                                        object_old_raw);
> unlock:

Ok sorry, professional deformation (goto).

>> +     mutex_unlock(&data->lock);
>> +     return ret;
>> +}
>> +
>> +static int mlx90632_read_ee_register(struct regmap *regmap, u16 reg_lsb,
>> +                                  s32 *reg_value)
>> +{
>> +     s32 ret;
>> +     unsigned int read;
>> +     __le32 value;
>> +
>> +     ret = regmap_read(regmap, reg_lsb, &read);
>> +     if (ret < 0)
>> +             return ret;
>> +
>> +     value = cpu_to_le32(read);
>
> Why would you be converting to le32 to then do
> calculations in here using it at cpu endianness?
> (guessing you want le32_to_cpu..)
>
> hmm isn't any relevant endian conversion wrapped up in regmap
> anyway?
>

Regmap reads 16 bit values, but some values are 32 bit. To avoid CPU
endianess affecting this, I am putting it to known time and shift values.
This way I ensured it is working on any CPU. le32_to_cpu is in return value.

>> +
>> +     ret = regmap_read(regmap, reg_lsb + 1, &read);
>> +     if (ret < 0)
>> +             return ret;
>> +
>> +     value = (cpu_to_le32(read) << 16) | (value & 0xffff);
>> +
>> +     *reg_value = le32_to_cpu(value);
>> +     return 0;
>> +}
>> +
>> +static s64 mlx90632_preprocess_temp_amb(s16 ambient_new_raw,
>> +                                     s16 ambient_old_raw, s16 Gb)
>> +{
>> +     s64 VR_Ta, kGb, tmp;
>> +
>> +     kGb = ((s64)Gb * TENTO3) >> 10ULL;
>> +     VR_Ta = (s64)ambient_old_raw * TENTO6 +
>> +             kGb * div64_s64(((s64)ambient_new_raw * TENTO3),
>> +                     (MLX90632_REF_3));
>> +     tmp = div64_s64(
>> +                      div64_s64(((s64)ambient_new_raw * TENTO12),
>> +                                (MLX90632_REF_3)), VR_Ta);
>> +     return div64_s64(tmp << 19ULL, TENTO3);
>> +}
>> +
>> +static s64 mlx90632_preprocess_temp_obj(s16 object_new_raw, s16 object_old_raw,
>> +                                     s16 ambient_new_raw,
>> +                                     s16 ambient_old_raw, s16 Ka)
>> +{
>> +     s64 VR_IR, kKa, tmp;
>> +
>> +     kKa = ((s64)Ka * TENTO3) >> 10ULL;
>> +     VR_IR = (s64)ambient_old_raw * TENTO6 +
>> +             kKa * div64_s64(((s64)ambient_new_raw * TENTO3),
>> +                     (MLX90632_REF_3));
>> +     tmp = div64_s64(
>> +                     div64_s64(((s64)((object_new_raw + object_old_raw) / 2)
>> +                                * TENTO12), (MLX90632_REF_12)), VR_IR);
>> +     return div64_s64(tmp << 19ULL), TENTO3);
>> +}
>> +
>> +static s32 mlx90632_calc_temp_ambient(s16 ambient_new_raw, s16 ambient_old_raw,
>> +                                   s32 P_T, s32 P_R, s32 P_G, s32 P_O,
>> +                                   s16 Gb)
>> +{
>> +     s64 Asub, Bsub, Ablock, Bblock, Cblock, AMB, sum;
>> +
>> +     AMB = mlx90632_preprocess_temp_amb(ambient_new_raw, ambient_old_raw,
>> +                                        Gb);
>> +     Asub = ((s64)P_T * TENTO10) >> 44ULL;
>> +     Bsub = AMB - (((s64)P_R * TENTO3) >> 8ULL);
>> +     Ablock = Asub * (Bsub * Bsub);
>> +     Bblock = (div64_s64(Bsub * TENTO7, P_G)) << 20ULL;
>> +     Cblock = ((s64)P_O * TENTO10) >> 8ULL;
>> +
>> +     sum = div64_s64(Ablock, TENTO6) + Bblock + Cblock;
>> +
>> +     return div64_s64(sum, TENTO7);
>> +}
>> +
>> +static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
>> +                                            s64 TAdut, s32 Fa, s32 Fb,
>> +                                            s32 Ga, s16 Ha, s16 Hb,
>> +                                            u16 emissivity)
>> +{
>> +     s64 calcedKsTO, calcedKsTA, ir_Alpha, TAdut4, Alpha_corr;
>> +     s64 Ha_customer, Hb_customer;
>> +
>> +     Ha_customer = ((s64)Ha * TENTO6) >> 14ULL;
>> +     Hb_customer = ((s64)Hb * 100) >> 10ULL;
>> +
>> +     calcedKsTO = ((s64)((s64)Ga * (prev_object_temp - 25 * TENTO3)
>> +                          * TENTO3)) >> 36LL;
>> +     calcedKsTA = ((s64)(Fb * (TAdut - 25 * TENTO6))) >> 36LL;
>> +     Alpha_corr = div64_s64((((s64)(Fa * TENTO10) >> 46LL) * Ha_customer),
>> +                            TENTO3);
>> +     Alpha_corr *= ((s64)(1 * TENTO6 + calcedKsTO + calcedKsTA));
>> +     Alpha_corr = emissivity * div64_s64(Alpha_corr, TENTO5);
>> +     Alpha_corr = div64_s64(Alpha_corr, TENTO3);
>> +     ir_Alpha = div64_s64((s64)object * TENTO7, Alpha_corr);
>> +     TAdut4 = (div64_s64(TAdut, TENTO4) + 27315) *
>> +             (div64_s64(TAdut, TENTO4) + 27315) *
>> +             (div64_s64(TAdut, TENTO4)  + 27315) *
>> +             (div64_s64(TAdut, TENTO4) + 27315);
>> +
>> +     return (mlx90632_int_sqrt(
>> +                      mlx90632_int_sqrt(ir_Alpha * TENTO12 + TAdut4)
>> +                     ) - 27315 - Hb_customer) * 10;
>> +}
>> +
>> +static s32 mlx90632_calc_temp_object(s64 object, s64 ambient, s32 Ea, s32 Eb,
>> +                                  s32 Fa, s32 Fb, s32 Ga, s16 Ha, s16 Hb,
>> +                                  u16 tmp_emi)
>> +{
>> +     s64 kTA, kTA0, TAdut;
>> +     s64 temp = 25000;
>> +     s8 i;
>> +
>> +     kTA = (Ea * TENTO3) >> 16LL;
>> +     kTA0 = (Eb * TENTO3) >> 8LL;
>> +     TAdut = div64_s64(((ambient - kTA0) * TENTO6), kTA) + 25 * TENTO6;
>> +
>> +     for (i = 0; i < 5; ++i) {
> comment on why iterations are needed would be good here.

This is described in datasheet (the whole calculation). Will add
explanatory comment.

>> +             temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut,
>> +                                                        Fa, Fb, Ga, Ha, Hb,
>> +                                                        tmp_emi);
>> +     }
>> +     return temp;
>> +}
>> +
>> +static int mlx90632_calc_object_dsp105(struct mlx90632_data *data, int *val)
>> +{
>> +     s32 ret;
>> +     s32 Ea, Eb, Fa, Fb, Ga;
>> +     unsigned int read_tmp;
>> +     s16 Ha, Hb, Gb, Ka;
>> +     s16 ambient_new_raw, ambient_old_raw, object_new_raw, object_old_raw;
>> +     s64 object, ambient;
>> +
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ea, &Ea);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Eb, &Eb);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fa, &Fa);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fb, &Fb);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ga, &Ga);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = regmap_read(data->regmap, MLX90632_EE_Ha, &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     Ha = (s16)read_tmp;
>> +     ret = regmap_read(data->regmap, MLX90632_EE_Hb, &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     Hb = (s16)read_tmp;
>> +     ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     Gb = (s16)read_tmp;
>> +     ret = regmap_read(data->regmap, MLX90632_EE_Ka, &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     Ka = (s16)read_tmp;
>> +
>> +     ret = mlx90632_read_all_channel(data,
>> +                                     &ambient_new_raw, &ambient_old_raw,
>> +                                     &object_new_raw, &object_old_raw);
>> +     if (ret < 0)
>> +             return ret;
>> +
>> +     ambient = mlx90632_preprocess_temp_amb(ambient_new_raw,
>> +                                            ambient_old_raw, Gb);
>> +     object = mlx90632_preprocess_temp_obj(object_new_raw,
>> +                                           object_old_raw,
>> +                                           ambient_new_raw,
>> +                                           ambient_old_raw, Ka);
>> +
>> +     *val = mlx90632_calc_temp_object(object, ambient, Ea, Eb, Fa, Fb, Ga,
>> +                                      Ha, Hb, data->emissivity);
>> +     return 0;
>> +}
>> +
>> +static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
>> +{
>> +     s32 ret;
>> +     unsigned int read_tmp;
>> +     s32 PT, PR, PG, PO;
>> +     s16 Gb;
>> +     s16 ambient_new_raw, ambient_old_raw;
>> +
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_R, &PR);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_G, &PG);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_T, &PT);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_O, &PO);
>> +     if (ret < 0)
>> +             return ret;
>> +     ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
>> +     if (ret < 0)
>> +             return ret;
>> +     Gb = (s16)read_tmp;
>> +
>> +     ret = mlx90632_read_ambient_raw(data->regmap, &ambient_new_raw,
>> +                                     &ambient_old_raw);
>> +     *val = mlx90632_calc_temp_ambient(ambient_new_raw, ambient_old_raw,
>> +                                       PT, PR, PG, PO, Gb);
>> +     return ret;
>> +}
>> +
>> +static int mlx90632_read_raw(struct iio_dev *indio_dev,
>> +                          struct iio_chan_spec const *channel, int *val,
>> +                          int *val2, long mask)
>> +{
>> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     switch (mask) {
>> +     case IIO_CHAN_INFO_PROCESSED:
>> +             switch (channel->channel2) {
>> +             case IIO_MOD_TEMP_AMBIENT:
>> +                     ret = mlx90632_calc_ambient_dsp105(data, val);
>> +                     if (ret < 0)
>> +                             return ret;
>> +                     return IIO_VAL_INT;
>> +             case IIO_MOD_TEMP_OBJECT:
>> +                     ret = mlx90632_calc_object_dsp105(data, val);
>> +                     if (ret < 0)
>> +                             return ret;
>> +                     return IIO_VAL_INT;
>> +             default:
>> +                     return -EINVAL;
>> +             }
>> +     case IIO_CHAN_INFO_CALIBEMISSIVITY:
>> +             if (data->emissivity == 1000) {
>> +                     *val = 1;
>> +                     *val2 = 0;
>> +             } else {
>> +                     *val = 0;
>> +                     *val2 = data->emissivity;
> Odd given you are reporting as int + nano
> this goes from 1.0 to 0.000000999 in one step?
> Seems unlikely..  If it is true then a comment
> is needed.
>
> The write is int + micro but this would still be wrong
> without a factor of 1000.
>

In input (write) below I am adding factor of 1000. I do not know
if resolution like that is needed, but you never know what they
come up with in real life so I rather left some of the breating
space.

>> +             }
>> +             return IIO_VAL_INT_PLUS_NANO;
>> +
>> +     default:
>> +             return -EINVAL;
>> +     }
>> +}
>> +
>> +static int mlx90632_write_raw(struct iio_dev *indio_dev,
>> +                           struct iio_chan_spec const *channel, int val,
>> +                           int val2, long mask)
>> +{
>> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> +
>> +     switch (mask) {
>> +     case IIO_CHAN_INFO_CALIBEMISSIVITY:
>> +             if (val < 0 || val2 < 0 || val > 1 ||
>> +                 (val == 1 && val2 != 0))
>
> I'd add a comment describing what this is doing.  I think it
> is checking for 0-1.0 inclusive?
>

Yes, exactly. In case you set emissivity outside of range it should
not change it and return EINVAL.

>> +                     return -EINVAL;
>> +             data->emissivity = val * 1000 + val2 / 1000;
>> +             return 0;
>> +     default:
>> +             return -EINVAL;
>> +     }
>> +}
>> +
>> +static const struct iio_chan_spec mlx90632_channels[] = {
>> +     {
>> +             .type = IIO_TEMP,
>> +             .modified = 1,
>> +             .channel2 = IIO_MOD_TEMP_AMBIENT,
>> +             .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
>> +     },
>> +     {
>> +             .type = IIO_TEMP,
>> +             .modified = 1,
>> +             .channel2 = IIO_MOD_TEMP_OBJECT,
>> +             .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
>> +                     BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
>> +     },
>> +};
>> +
>> +static const struct iio_info mlx90632_info = {
>> +     .read_raw = mlx90632_read_raw,
>> +     .write_raw = mlx90632_write_raw,
>> +};
>> +
>> +#ifdef CONFIG_PM
>> +static int mlx90632_sleep(struct mlx90632_data *data)
>> +{
>> +     dev_dbg(&data->client->dev, "Requesting sleep");
>> +     return mlx90632_pwr_set_sleep_step(data->regmap);
>> +}
>> +
>> +static int mlx90632_wakeup(struct mlx90632_data *data)
>> +{
>> +     dev_dbg(&data->client->dev, "Requesting wake-up");
>> +     return mlx90632_pwr_continuous(data->regmap);
>> +}
>> +#endif
>> +
>> +static int mlx90632_probe(struct i2c_client *client,
>> +                       const struct i2c_device_id *id)
>> +{
>> +     struct iio_dev *indio_dev;
>> +     struct mlx90632_data *mlx90632;
>> +     struct regmap *regmap;
>> +     int ret;
>> +     unsigned int read;
>> +
>> +     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*mlx90632));
>> +     if (!indio_dev) {
>> +             dev_err(&client->dev, "Failed to allocate device");
>> +             return -ENOMEM;
>> +     }
>> +
>> +     regmap = devm_regmap_init_i2c(client, &mlx90632_regmap);
>> +     if (IS_ERR(regmap)) {
>> +             ret = PTR_ERR(regmap);
>> +             dev_err(&client->dev, "Failed to allocate regmap: %d\n", ret);
>> +             return ret;
>> +     }
>> +
>> +     mlx90632 = iio_priv(indio_dev);
>> +     i2c_set_clientdata(client, indio_dev);
>> +     mlx90632->client = client;
>> +     mlx90632->regmap = regmap;
>> +
>> +     mutex_init(&mlx90632->lock);
>> +     mlx90632_wakeup(mlx90632);
>> +
>> +     indio_dev->dev.parent = &client->dev;
>> +     indio_dev->name = id->name;
>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>> +     indio_dev->info = &mlx90632_info;
>> +     indio_dev->channels = mlx90632_channels;
>> +     indio_dev->num_channels = ARRAY_SIZE(mlx90632_channels);
>> +
>> +     ret = regmap_read(mlx90632->regmap, MLX90632_EE_VERSION, &read);
>> +     if (ret < 0) {
>> +             dev_err(&client->dev, "read of version failed: %d\n", ret);
>> +             return ret;
>> +     }
>> +     if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_MEDICAL)) {
>
> This is odd.  Why the bitwise and of what look to be two different things entirely?
>

If you look at how they are set (high vs low bits) you will see they
are complimentary and
prepared exactly for bitwise check. ID_MEDICAL might not be best name, but
EEPROM_ID_MEDICAL was just too long. You read 16 bits and that is why
lower 8 bits
are in fact EEPROM_VERSION while higher 8 are ID of calibration. Since
calculations
are currently dependent on lower 8 bits, I left some of the wiggle
space for future.
In case we add another one in future, but I would rather have a strict
check for this to
avoid any kind of confusion what is supported.

>> +             dev_dbg(&client->dev,
>> +                     "Detected Medical EEPROM calibration %x", read);
>> +     } else if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_CONSUMER)) {
>> +             dev_dbg(&client->dev,
>> +                     "Detected Consumer EEPROM calibration %x", read);
>> +     } else {
>> +             dev_err(&client->dev,
>> +                     "Chip EEPROM version mismatch %x (expected %x)",
>> +                     read, MLX90632_EEPROM_VERSION);
>> +             return -EPROTONOSUPPORT;
>> +     }
>> +
>> +     mlx90632->emissivity = 1000;
>> +
>> +     return devm_iio_device_register(&client->dev, indio_dev);
>
> Don't use devm version.  You are (correctly) manually unwinding
> this in the remove (as you have pm to deal with after removing the
> interfaces).  This will result in a double free I think...
> return iio_device_register is the way to go.
>
> I'm a bit confused that you don't seem to set up runtime pm anywhere...
> I would assume we would be looking at autosuspend for a device
> like this but it isn't enabled..
>

OK, will check how to use iio_device_register instead.

I did not do much of PM on device, so I can't really say. That is
why autosuspend is not enabled.

>> +}
>> +
>> +static int mlx90632_remove(struct i2c_client *client)
>> +{
>> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> +
>> +     iio_device_unregister(indio_dev);
>> +
>> +     pm_runtime_disable(&client->dev);
>> +     if (!pm_runtime_status_suspended(&client->dev))
>> +             mlx90632_sleep(data);
>> +     pm_runtime_set_suspended(&client->dev);
>> +
>> +     return 0;
>> +}
>> +
>> +static const struct i2c_device_id mlx90632_id[] = {
>> +     { "mlx90632", 0 },
>> +     { }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, mlx90632_id);
>> +
>> +static const struct of_device_id mlx90632_of_match[] = {
>> +     { .compatible = "melexis,mlx90632" },
>> +     { }
>> +};
>> +MODULE_DEVICE_TABLE(of, mlx90632_of_match);
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int mlx90632_pm_suspend(struct device *dev)
>> +{
>> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> +
>> +     if (pm_runtime_active(dev))
>> +             return mlx90632_sleep(data);
>
> I'm a little confused as to why, if the device is powered
> up fully and a suspend comes in we have to do less than we do
> in runtime pm case.
>
> Am I missing something?
>

I think I have mostly tested runtime pm case, so this might have
been missed. I did get wrong results if I did not mark regcache as dirty.

I will just remove the whole PM thing to start with and add it up later, OK?

>> +
>> +     return 0;
>> +}
>> +
>> +static int mlx90632_pm_resume(struct device *dev)
>> +{
>> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> +     int err;
>> +
>> +     err = mlx90632_wakeup(data);
>> +     if (err < 0)
>> +             return err;
>> +
>> +     pm_runtime_disable(dev);
>> +     pm_runtime_set_active(dev);
>> +     pm_runtime_enable(dev);
>> +
>> +     return 0;
>> +}
>> +#endif
>> +
>> +#ifdef CONFIG_PM
>> +static int mlx90632_pm_runtime_suspend(struct device *dev)
>> +{
>> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +     struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
>> +
>> +     regcache_sync(mlx90632->regmap);
>> +
>> +     return mlx90632_sleep(mlx90632);
>> +}
>> +
>> +static int mlx90632_pm_runtime_resume(struct device *dev)
>> +{
>> +     s32 ret;
>> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> +     struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
>> +
>> +     regcache_mark_dirty(mlx90632->regmap);
>> +     regcache_cache_only(mlx90632->regmap, false);
>> +     ret = regcache_sync(mlx90632->regmap);
>> +     if (ret < 0) {
>> +             dev_err(dev, "Failed to sync regmap registers: %d\n", ret);
>> +             return ret;
>> +     }
>> +
>> +     return mlx90632_wakeup(mlx90632);
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops mlx90632_pm_ops = {
>> +     SET_SYSTEM_SLEEP_PM_OPS(mlx90632_pm_suspend, mlx90632_pm_resume)
>> +     SET_RUNTIME_PM_OPS(mlx90632_pm_runtime_suspend,
>> +                        mlx90632_pm_runtime_resume, NULL)
>> +};
>> +
>> +static struct i2c_driver mlx90632_driver = {
>> +     .driver = {
>> +             .name   = "mlx90632",
>> +             .of_match_table = mlx90632_of_match,
>> +             .pm     = &mlx90632_pm_ops,
>> +     },
>> +     .probe = mlx90632_probe,
>> +     .remove = mlx90632_remove,
>> +     .id_table = mlx90632_id,
>> +};
>> +module_i2c_driver(mlx90632_driver);
>> +
>> +MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
>> +MODULE_DESCRIPTION("Melexis MLX90632 contactless Infra Red temperature sensor driver");
>> +MODULE_LICENSE("GPL v2");
>
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Jonathan Cameron Dec. 5, 2017, 11:23 a.m. UTC | #3
On Sat, 2 Dec 2017 21:30:54 +0100
Crt Mori <cmo@melexis.com> wrote:

> Hi Jonathan,
> Definitely did not think there will be so many comments inside, but I
> expected few of them indeed.
> 
> See my replies inside.
> 
> On 2 December 2017 at 15:33, Jonathan Cameron <jic23@kernel.org> wrote:
> > On Wed, 29 Nov 2017 23:07:49 +0100
> > Crt Mori <cmo@melexis.com> wrote:
> >  
> >> Melexis has just released Infra Red temperature sensor MLX90632 used
> >> for contact-less temperature measurement. Driver provides basic
> >> functionality for reporting object (and ambient) temperature with
> >> support for object emissivity.
> >>
> >> Signed-off-by: Crt Mori <cmo@melexis.com>  
> >
> > Various comments inline.
> >  
> >> ---
> >>  MAINTAINERS                        |   7 +
> >>  drivers/iio/temperature/Kconfig    |  12 +
> >>  drivers/iio/temperature/Makefile   |   1 +
> >>  drivers/iio/temperature/mlx90632.c | 802 +++++++++++++++++++++++++++++++++++++
> >>  4 files changed, 822 insertions(+)
> >>  create mode 100644 drivers/iio/temperature/mlx90632.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index 2d3d750b19c0..81aec02b08b8 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -8690,6 +8690,13 @@ W:     http://www.melexis.com
> >>  S:   Supported
> >>  F:   drivers/iio/temperature/mlx90614.c
> >>
> >> +MELEXIS MLX90632 DRIVER
> >> +M:   Crt Mori <cmo@melexis.com>
> >> +L:   linux-iio@vger.kernel.org
> >> +W:   http://www.melexis.com
> >> +S:   Supported
> >> +F:   drivers/iio/temperature/mlx90632.c
> >> +
> >>  MELFAS MIP4 TOUCHSCREEN DRIVER
> >>  M:   Sangwon Jee <jeesw@melfas.com>
> >>  W:   http://www.melfas.com
> >> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
> >> index 5378976d6d27..82e4a62745e2 100644
> >> --- a/drivers/iio/temperature/Kconfig
> >> +++ b/drivers/iio/temperature/Kconfig
> >> @@ -43,6 +43,18 @@ config MLX90614
> >>         This driver can also be built as a module. If so, the module will
> >>         be called mlx90614.
> >>
> >> +config MLX90632
> >> +     tristate "MLX90632 contact-less infrared sensor with medical accuracy"
> >> +     depends on I2C
> >> +     select REGMAP_I2C
> >> +     help
> >> +       If you say yes here you get support for the Melexis
> >> +       MLX90632 contact-less infrared sensor with medical accuracy
> >> +       connected with I2C.
> >> +
> >> +       This driver can also be built as a module. If so, the module will
> >> +       be called mlx90632.
> >> +
> >>  config TMP006
> >>       tristate "TMP006 infrared thermopile sensor"
> >>       depends on I2C
> >> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
> >> index ad1d668de546..44644fe01bc9 100644
> >> --- a/drivers/iio/temperature/Makefile
> >> +++ b/drivers/iio/temperature/Makefile
> >> @@ -5,6 +5,7 @@
> >>  obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
> >>  obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
> >>  obj-$(CONFIG_MLX90614) += mlx90614.o
> >> +obj-$(CONFIG_MLX90632) += mlx90632.o
> >>  obj-$(CONFIG_TMP006) += tmp006.o
> >>  obj-$(CONFIG_TMP007) += tmp007.o
> >>  obj-$(CONFIG_TSYS01) += tsys01.o
> >> diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
> >> new file mode 100644
> >> index 000000000000..05c7d943e504
> >> --- /dev/null
> >> +++ b/drivers/iio/temperature/mlx90632.c
> >> @@ -0,0 +1,802 @@
> >> +/*
> >> + * mlx90632.c - Melexis MLX90632 contactless IR temperature sensor
> >> + *
> >> + * Copyright (c) 2017 Melexis <cmo@melexis.com>
> >> + *
> >> + * This file is subject to the terms and conditions of version 2 of
> >> + * the GNU General Public License.  See the file COPYING in the main
> >> + * directory of this archive for more details.
> >> + *
> >> + * Driver for the Melexis MLX90632 I2C 16-bit IR thermopile sensor
> >> + */
> >> +#include <asm/byteorder.h>  
> > Don't think this should ever be included in a driver.
> > What do you need it for?
> >  
> >> +#include <linux/delay.h>
> >> +#include <linux/err.h>
> >> +#include <linux/gpio/consumer.h>
> >> +#include <linux/i2c.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/math64.h>
> >> +#include <linux/of.h>
> >> +#include <linux/pm_runtime.h>
> >> +#include <linux/regmap.h>
> >> +#include <linux/unaligned/be_byteshift.h>  
> > why?
> >  
> >> +
> >> +#include <linux/iio/iio.h>
> >> +#include <linux/iio/sysfs.h>
> >> +
> >> +/* Memory sections addresses */
> >> +#define MLX90632_ADDR_RAM    0x4000 /* Start address of ram */
> >> +#define MLX90632_ADDR_EEPROM 0x2480 /* Start address of user eeprom */
> >> +
> >> +/* EEPROM addresses - used at startup */
> >> +#define MLX90632_EE_CTRL     0x24d4 /* Control register initial value */
> >> +#define MLX90632_EE_I2C_ADDR 0x24d5 /* I2C address register initial value */
> >> +#define MLX90632_EE_VERSION  0x240b /* EEPROM version reg address */
> >> +#define MLX90632_EE_P_R              0x240c /* P_R calibration register 32bit */
> >> +#define MLX90632_EE_P_G              0x240e /* P_G calibration register 32bit */
> >> +#define MLX90632_EE_P_T              0x2410 /* P_T calibration register 32bit */
> >> +#define MLX90632_EE_P_O              0x2412 /* P_O calibration register 32bit */
> >> +#define MLX90632_EE_Aa               0x2414 /* Aa calibration register 32bit */
> >> +#define MLX90632_EE_Ab               0x2416 /* Ab calibration register 32bit */
> >> +#define MLX90632_EE_Ba               0x2418 /* Ba calibration register 32bit */
> >> +#define MLX90632_EE_Bb               0x241a /* Bb calibration register 32bit */
> >> +#define MLX90632_EE_Ca               0x241c /* Ca calibration register 32bit */
> >> +#define MLX90632_EE_Cb               0x241e /* Cb calibration register 32bit */
> >> +#define MLX90632_EE_Da               0x2420 /* Da calibration register 32bit */
> >> +#define MLX90632_EE_Db               0x2422 /* Db calibration register 32bit */
> >> +#define MLX90632_EE_Ea               0x2424 /* Ea calibration register 32bit */
> >> +#define MLX90632_EE_Eb               0x2426 /* Eb calibration register 32bit */
> >> +#define MLX90632_EE_Fa               0x2428 /* Fa calibration register 32bit */
> >> +#define MLX90632_EE_Fb               0x242a /* Fb calibration register 32bit */
> >> +#define MLX90632_EE_Ga               0x242c /* Ga calibration register 32bit */
> >> +
> >> +#define MLX90632_EE_Gb               0x242e /* Gb calibration register 16bit */
> >> +#define MLX90632_EE_Ka               0x242f /* Ka calibration register 16bit */
> >> +
> >> +#define MLX90632_EE_Ha               0x2481 /* Ha customer calib value reg 16bit */
> >> +#define MLX90632_EE_Hb               0x2482 /* Hb customer calib value reg 16bit */
> >> +
> >> +/* Register addresses - volatile */
> >> +#define MLX90632_REG_I2C_ADDR        0x3000 /* Chip I2C address register */
> >> +
> >> +/* Control register address - volatile */
> >> +#define MLX90632_REG_CONTROL 0x3001 /* Control Register address */
> >> +#define   MLX90632_CFG_PWR_MASK              GENMASK(2, 1) /* PowerMode Mask */
> >> +/* PowerModes statuses */
> >> +#define MLX90632_PWR_STATUS(ctrl_val) (ctrl_val << 1)
> >> +#define MLX90632_PWR_STATUS_HALT MLX90632_PWR_STATUS(0) /* hold */
> >> +#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step*/
> >> +#define MLX90632_PWR_STATUS_STEP MLX90632_PWR_STATUS(2) /* step */
> >> +#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous*/
> >> +
> >> +/* Device status register - volatile */
> >> +#define MLX90632_REG_STATUS  0x3fff /* Device status register */
> >> +#define   MLX90632_STAT_BUSY         BIT(10) /* Device busy indicator */
> >> +#define   MLX90632_STAT_EE_BUSY              BIT(9) /* EEPROM busy indicator */
> >> +#define   MLX90632_STAT_BRST         BIT(8) /* Brown out reset indicator */
> >> +#define   MLX90632_STAT_CYCLE_POS    GENMASK(6, 2) /* Data position */
> >> +#define   MLX90632_STAT_DATA_RDY     BIT(0) /* Data ready indicator */
> >> +
> >> +/* RAM_MEAS address-es for each channel */
> >> +#define MLX90632_RAM_1(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num)
> >> +#define MLX90632_RAM_2(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num + 1)
> >> +#define MLX90632_RAM_3(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num + 2)
> >> +
> >> +/* Magic constants */
> >> +#define MLX90632_EEPROM_VERSION      0xff05 /* EEPROM DSP version for constants */
> >> +#define MLX90632_ID_MEDICAL  0x01ff /* EEPROM Medical device id */
> >> +#define MLX90632_ID_CONSUMER 0x02ff /* EEPROM Consumer device id */
> >> +#define MLX90632_EEPROM_WRITE_KEY 0x554C /* EEPROM write key 0x55 and 0x4c */
> >> +#define MLX90632_RESET_CMD   0x0006 /* Reset sensor (address or global) */
> >> +#define MLX90632_REF_12              12LL /**< ResCtrlRef value of Ch 1 or Ch 2 */
> >> +#define MLX90632_REF_3               12LL /**< ResCtrlRef value of Channel 3 */
> >> +
> >> +#define TENTO3                       1000LL
> >> +#define TENTO4                       10000LL
> >> +#define TENTO5                       100000LL
> >> +#define TENTO6                       1000000LL
> >> +#define TENTO7                       10000000LL
> >> +#define TENTO10                      10000000000LL
> >> +#define TENTO12                      1000000000000LL  
> > Umm. The numbers describe the constants rather better than the defines ;)
> > Just use the numbers if you need them!
> >  
> 
> This is way shorter (line length) and more readable in my opinion.
> Also writing 12 times 0 is error prone :D

Needs care but I really don't like these constants.

> 
> >> +
> >> +struct mlx90632_data {
> >> +     struct i2c_client *client;
> >> +     struct mutex lock; /* Multiple reads for single measurement */
> >> +     struct regmap *regmap;
> >> +     u16 emissivity;
> >> +};
> >> +
> >> +static const struct regmap_range mlx90632_volatile_reg_range[] = {
> >> +     regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
> >> +     regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
> >> +     regmap_reg_range(MLX90632_RAM_1(0),
> >> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
> >> +};
> >> +
> >> +static const struct regmap_access_table mlx90632_volatile_regs_tbl = {
> >> +     .yes_ranges = mlx90632_volatile_reg_range,
> >> +     .n_yes_ranges = ARRAY_SIZE(mlx90632_volatile_reg_range),
> >> +};
> >> +
> >> +static const struct regmap_range mlx90632_read_reg_range[] = {
> >> +     regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
> >> +     regmap_reg_range(MLX90632_EE_CTRL, MLX90632_EE_I2C_ADDR),
> >> +     regmap_reg_range(MLX90632_EE_Ha, MLX90632_EE_Hb),
> >> +     regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
> >> +     regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
> >> +     regmap_reg_range(MLX90632_RAM_1(0),
> >> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
> >> +};
> >> +
> >> +static const struct regmap_access_table mlx90632_readable_regs_tbl = {
> >> +     .yes_ranges = mlx90632_read_reg_range,
> >> +     .n_yes_ranges = ARRAY_SIZE(mlx90632_read_reg_range),
> >> +};
> >> +
> >> +static const struct regmap_range mlx90632_no_write_reg_range[] = {
> >> +     regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
> >> +     regmap_reg_range(MLX90632_RAM_1(0),
> >> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
> >> +};
> >> +
> >> +static const struct regmap_access_table mlx90632_writeable_regs_tbl = {
> >> +     .no_ranges = mlx90632_no_write_reg_range,
> >> +     .n_no_ranges = ARRAY_SIZE(mlx90632_no_write_reg_range),
> >> +};
> >> +
> >> +static const struct regmap_config mlx90632_regmap = {
> >> +     .reg_bits = 16,
> >> +     .val_bits = 16,
> >> +
> >> +     .volatile_table = &mlx90632_volatile_regs_tbl,
> >> +     .rd_table = &mlx90632_readable_regs_tbl,
> >> +     .wr_table = &mlx90632_writeable_regs_tbl,
> >> +
> >> +     .use_single_rw = true,
> >> +     .reg_format_endian = REGMAP_ENDIAN_BIG,
> >> +     .val_format_endian = REGMAP_ENDIAN_BIG,
> >> +     .cache_type = REGCACHE_RBTREE,
> >> +};
> >> +
> >> +static u64 mlx90632_int_sqrt(u64 x)
> >> +{
> >> +     u64 b, m, y = 0;
> >> +
> >> +     if (BITS_PER_LONG != 32)
> >> +             return int_sqrt(x);  
> >
> > needs a comment on why...
> > Ideally propose a standard 64 bit routine if one is needed for
> > 32 bit machines.
> >  
> 
> Problem is that int_sqrt is not strongly typed. That means 64 bit
> number gets truncated to 32bit on 32bit machine as you mentioned
> and that caused quite many headaches in my testing (worked on
> mobile phone, but not on beaglebone black).  This solution is just
> stronger typing of int_sqrt function.
> 
> If you think I should put it onto math.h as a patch I can try it.

Sure, let's see if that goes anywhere.  Seems the right approach to me.

> 
> >> +
> >> +     if (x <= 1)
> >> +             return x;
> >> +
> >> +     m = 1ULL << (64 - 2);
> >> +     while (m != 0) {
> >> +             b = y + m;
> >> +             y >>= 1;
> >> +
> >> +             if (x >= b) {
> >> +                     x -= b;
> >> +                     y += m;
> >> +             }
> >> +             m >>= 2;
> >> +     }
> >> +     return y;
> >> +}
> >> +
> >> +static s32 mlx90632_pwr_set_sleep_step(struct regmap *regmap)
> >> +{
> >> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
> >> +                               MLX90632_CFG_PWR_MASK,
> >> +                               MLX90632_PWR_STATUS_SLEEP_STEP);
> >> +}
> >> +
> >> +static s32 mlx90632_pwr_set_step(struct regmap *regmap)
> >> +{
> >> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
> >> +                               MLX90632_CFG_PWR_MASK,
> >> +                               MLX90632_PWR_STATUS_STEP);
> >> +}
> >> +
> >> +static s32 mlx90632_pwr_continuous(struct regmap *regmap)
> >> +{
> >> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
> >> +                               MLX90632_CFG_PWR_MASK,
> >> +                               MLX90632_PWR_STATUS_CONTINUOUS);
> >> +}
> >> +
> >> +static int mlx90632_start_measurement(struct mlx90632_data *data)  
> >
> > Looks superficially to me like this is actually waiting for a reading
> > to complete rather than just starting it?  If so change the name
> > to reflect that.
> >  
> 
> ok
> 
> >> +{
> >> +     int ret, tries = 100;
> >> +     unsigned int reg_status;
> >> +
> >> +     ret = regmap_update_bits(data->regmap, MLX90632_REG_STATUS,
> >> +                              MLX90632_STAT_DATA_RDY, 0);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +
> >> +     while (tries-- > 0) {
> >> +             ret = regmap_read(data->regmap, MLX90632_REG_STATUS,
> >> +                               &reg_status);
> >> +             if (ret < 0)
> >> +                     return ret;
> >> +             if (reg_status & MLX90632_STAT_DATA_RDY)
> >> +                     break;
> >> +             usleep_range(10000, 11000);
> >> +     }
> >> +
> >> +     if (tries < 0) {
> >> +             dev_err(&data->client->dev, "data not ready");
> >> +             return -ETIMEDOUT;
> >> +     }
> >> +
> >> +     return (reg_status & MLX90632_STAT_CYCLE_POS) >> 2;  
> >
> > This is a non obvious return value so I would suggest adding
> > some documentation to say what is going on here..
> >  
> 
> Yes, it is indeed.
> 
> >> +}
> >> +
> >> +static int mlx9032_channel_new_select(int ret, uint8_t *channel_new,
> >> +                                   uint8_t *channel_old)  
> >
> > don't use ret as a name for a variable being passed in.  Rather
> > confusing!
> >  
> 
> OK. I think I should just copy setting of channel_old and new in the
> only spot it is used.
> 
> >> +{
> >> +     if (ret == 1) {
> >> +             *channel_new = 1;
> >> +             *channel_old = 2;
> >> +     } else if (ret == 2) {
> >> +             *channel_new = 2;
> >> +             *channel_old = 1;
> >> +     } else {
> >> +             return ret;
> >> +     }
> >> +     return 0;  
> > Can't get here...
> >  
> 
> Not true. You get here in every example other than else where channel_new
> and channel_old are successfully set. but I agree there is a bug in case ret=0
> when it will return 0, but it will not set channels.

Ah good point, I missed that. I would do it as a switch with direct returns.

> 
> >> +}
> >> +
> >> +static int mlx90632_read_ambient_raw(struct regmap *regmap,
> >> +                                  s16 *ambient_new_raw, s16 *ambient_old_raw)
> >> +{
> >> +     int ret;
> >> +     unsigned int read_tmp;
> >> +
> >> +     ret = regmap_read(regmap, MLX90632_RAM_3(1), &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     *ambient_new_raw = (s16)read_tmp;
> >> +
> >> +     ret = regmap_read(regmap, MLX90632_RAM_3(2), &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     *ambient_old_raw = (s16)read_tmp;
> >> +
> >> +     return ret;
> >> +}
> >> +
> >> +static int mlx90632_read_object_raw(struct regmap *regmap,
> >> +                                 int start_measurement_ret,
> >> +                                 s16 *object_new_raw, s16 *object_old_raw)
> >> +{
> >> +     int ret;
> >> +     unsigned int read_tmp;
> >> +     s16 read;
> >> +     u8 channel = 0;
> >> +     u8 channel_old = 0;
> >> +
> >> +     ret = mlx90632_channel_new_select(start_measurement_ret, &channel,
> >> +                                       &channel_old);
> >> +     if (ret != 0)
> >> +             return ret;
> >> +
> >> +     ret = regmap_read(regmap, MLX90632_RAM_2(channel), &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +
> >> +     read = (s16)read_tmp;
> >> +
> >> +     ret = regmap_read(regmap, MLX90632_RAM_1(channel), &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     *object_new_raw = (read + (s16)read_tmp) / 2;
> >> +
> >> +     ret = regmap_read(regmap, MLX90632_RAM_2(channel_old), &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     read = (s16)read_tmp;
> >> +
> >> +     ret = regmap_read(regmap, MLX90632_RAM_1(channel_old), &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     *object_old_raw = (read + (s16)read_tmp) / 2;
> >> +
> >> +     return ret;
> >> +}
> >> +
> >> +static int mlx90632_read_all_channel(struct mlx90632_data *data,
> >> +                                  s16 *ambient_new_raw, s16 *ambient_old_raw,
> >> +                                  s16 *object_new_raw, s16 *object_old_raw)
> >> +{
> >> +     s32 ret, tm_ret;
> >> +
> >> +     mutex_lock(&data->lock);
> >> +     tm_ret = mlx90632_start_measurement(data);
> >> +     if (tm_ret >= 0) {
> >> +             ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
> >> +                                             ambient_old_raw);
> >> +             if (ret >= 0) {
> >> +                     ret = mlx90632_read_object_raw(data->regmap, tm_ret,
> >> +                                                    object_new_raw,
> >> +                                                    object_old_raw);
> >> +             }
> >> +     } else {
> >> +             ret = tm_ret;
> >> +     }  
> > Use something cleaner like
> >         mutex_lock(&data->lock);
> >         ret = mlx90632_start_measurement(data);
> >         if (ret < 0)
> >                 goto unlock;
> >         ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
> >                                         ambient_old_raw);
> >         if (ret < 0)
> >                 goto unlock;
> >
> >         ret = mlx90632_read_object_raw(data->regmap, tm_ret,
> >                                        object_new_raw,
> >                                        object_old_raw);
> > unlock:  
> 
> Ok sorry, professional deformation (goto).
> 
> >> +     mutex_unlock(&data->lock);
> >> +     return ret;
> >> +}
> >> +
> >> +static int mlx90632_read_ee_register(struct regmap *regmap, u16 reg_lsb,
> >> +                                  s32 *reg_value)
> >> +{
> >> +     s32 ret;
> >> +     unsigned int read;
> >> +     __le32 value;
> >> +
> >> +     ret = regmap_read(regmap, reg_lsb, &read);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +
> >> +     value = cpu_to_le32(read);  
> >
> > Why would you be converting to le32 to then do
> > calculations in here using it at cpu endianness?
> > (guessing you want le32_to_cpu..)
> >
> > hmm isn't any relevant endian conversion wrapped up in regmap
> > anyway?
> >  
> 
> Regmap reads 16 bit values, but some values are 32 bit. To avoid CPU
> endianess affecting this, I am putting it to known time and shift values.
> This way I ensured it is working on any CPU. le32_to_cpu is in return value.
>

I'm far from convinced this is a good idea. I would ensure all values
are in cpu endianness before combining them based on the read order
(which is endian independant)
 
> >> +
> >> +     ret = regmap_read(regmap, reg_lsb + 1, &read);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +
> >> +     value = (cpu_to_le32(read) << 16) | (value & 0xffff);
> >> +
> >> +     *reg_value = le32_to_cpu(value);
> >> +     return 0;
> >> +}
> >> +
> >> +static s64 mlx90632_preprocess_temp_amb(s16 ambient_new_raw,
> >> +                                     s16 ambient_old_raw, s16 Gb)
> >> +{
> >> +     s64 VR_Ta, kGb, tmp;
> >> +
> >> +     kGb = ((s64)Gb * TENTO3) >> 10ULL;
> >> +     VR_Ta = (s64)ambient_old_raw * TENTO6 +
> >> +             kGb * div64_s64(((s64)ambient_new_raw * TENTO3),
> >> +                     (MLX90632_REF_3));
> >> +     tmp = div64_s64(
> >> +                      div64_s64(((s64)ambient_new_raw * TENTO12),
> >> +                                (MLX90632_REF_3)), VR_Ta);
> >> +     return div64_s64(tmp << 19ULL, TENTO3);
> >> +}
> >> +
> >> +static s64 mlx90632_preprocess_temp_obj(s16 object_new_raw, s16 object_old_raw,
> >> +                                     s16 ambient_new_raw,
> >> +                                     s16 ambient_old_raw, s16 Ka)
> >> +{
> >> +     s64 VR_IR, kKa, tmp;
> >> +
> >> +     kKa = ((s64)Ka * TENTO3) >> 10ULL;
> >> +     VR_IR = (s64)ambient_old_raw * TENTO6 +
> >> +             kKa * div64_s64(((s64)ambient_new_raw * TENTO3),
> >> +                     (MLX90632_REF_3));
> >> +     tmp = div64_s64(
> >> +                     div64_s64(((s64)((object_new_raw + object_old_raw) / 2)
> >> +                                * TENTO12), (MLX90632_REF_12)), VR_IR);
> >> +     return div64_s64(tmp << 19ULL), TENTO3);
> >> +}
> >> +
> >> +static s32 mlx90632_calc_temp_ambient(s16 ambient_new_raw, s16 ambient_old_raw,
> >> +                                   s32 P_T, s32 P_R, s32 P_G, s32 P_O,
> >> +                                   s16 Gb)
> >> +{
> >> +     s64 Asub, Bsub, Ablock, Bblock, Cblock, AMB, sum;
> >> +
> >> +     AMB = mlx90632_preprocess_temp_amb(ambient_new_raw, ambient_old_raw,
> >> +                                        Gb);
> >> +     Asub = ((s64)P_T * TENTO10) >> 44ULL;
> >> +     Bsub = AMB - (((s64)P_R * TENTO3) >> 8ULL);
> >> +     Ablock = Asub * (Bsub * Bsub);
> >> +     Bblock = (div64_s64(Bsub * TENTO7, P_G)) << 20ULL;
> >> +     Cblock = ((s64)P_O * TENTO10) >> 8ULL;
> >> +
> >> +     sum = div64_s64(Ablock, TENTO6) + Bblock + Cblock;
> >> +
> >> +     return div64_s64(sum, TENTO7);
> >> +}
> >> +
> >> +static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
> >> +                                            s64 TAdut, s32 Fa, s32 Fb,
> >> +                                            s32 Ga, s16 Ha, s16 Hb,
> >> +                                            u16 emissivity)
> >> +{
> >> +     s64 calcedKsTO, calcedKsTA, ir_Alpha, TAdut4, Alpha_corr;
> >> +     s64 Ha_customer, Hb_customer;
> >> +
> >> +     Ha_customer = ((s64)Ha * TENTO6) >> 14ULL;
> >> +     Hb_customer = ((s64)Hb * 100) >> 10ULL;
> >> +
> >> +     calcedKsTO = ((s64)((s64)Ga * (prev_object_temp - 25 * TENTO3)
> >> +                          * TENTO3)) >> 36LL;
> >> +     calcedKsTA = ((s64)(Fb * (TAdut - 25 * TENTO6))) >> 36LL;
> >> +     Alpha_corr = div64_s64((((s64)(Fa * TENTO10) >> 46LL) * Ha_customer),
> >> +                            TENTO3);
> >> +     Alpha_corr *= ((s64)(1 * TENTO6 + calcedKsTO + calcedKsTA));
> >> +     Alpha_corr = emissivity * div64_s64(Alpha_corr, TENTO5);
> >> +     Alpha_corr = div64_s64(Alpha_corr, TENTO3);
> >> +     ir_Alpha = div64_s64((s64)object * TENTO7, Alpha_corr);
> >> +     TAdut4 = (div64_s64(TAdut, TENTO4) + 27315) *
> >> +             (div64_s64(TAdut, TENTO4) + 27315) *
> >> +             (div64_s64(TAdut, TENTO4)  + 27315) *
> >> +             (div64_s64(TAdut, TENTO4) + 27315);
> >> +
> >> +     return (mlx90632_int_sqrt(
> >> +                      mlx90632_int_sqrt(ir_Alpha * TENTO12 + TAdut4)
> >> +                     ) - 27315 - Hb_customer) * 10;
> >> +}
> >> +
> >> +static s32 mlx90632_calc_temp_object(s64 object, s64 ambient, s32 Ea, s32 Eb,
> >> +                                  s32 Fa, s32 Fb, s32 Ga, s16 Ha, s16 Hb,
> >> +                                  u16 tmp_emi)
> >> +{
> >> +     s64 kTA, kTA0, TAdut;
> >> +     s64 temp = 25000;
> >> +     s8 i;
> >> +
> >> +     kTA = (Ea * TENTO3) >> 16LL;
> >> +     kTA0 = (Eb * TENTO3) >> 8LL;
> >> +     TAdut = div64_s64(((ambient - kTA0) * TENTO6), kTA) + 25 * TENTO6;
> >> +
> >> +     for (i = 0; i < 5; ++i) {  
> > comment on why iterations are needed would be good here.  
> 
> This is described in datasheet (the whole calculation). Will add
> explanatory comment.
> 
> >> +             temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut,
> >> +                                                        Fa, Fb, Ga, Ha, Hb,
> >> +                                                        tmp_emi);
> >> +     }
> >> +     return temp;
> >> +}
> >> +
> >> +static int mlx90632_calc_object_dsp105(struct mlx90632_data *data, int *val)
> >> +{
> >> +     s32 ret;
> >> +     s32 Ea, Eb, Fa, Fb, Ga;
> >> +     unsigned int read_tmp;
> >> +     s16 Ha, Hb, Gb, Ka;
> >> +     s16 ambient_new_raw, ambient_old_raw, object_new_raw, object_old_raw;
> >> +     s64 object, ambient;
> >> +
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ea, &Ea);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Eb, &Eb);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fa, &Fa);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fb, &Fb);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ga, &Ga);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Ha, &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     Ha = (s16)read_tmp;
> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Hb, &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     Hb = (s16)read_tmp;
> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     Gb = (s16)read_tmp;
> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Ka, &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     Ka = (s16)read_tmp;
> >> +
> >> +     ret = mlx90632_read_all_channel(data,
> >> +                                     &ambient_new_raw, &ambient_old_raw,
> >> +                                     &object_new_raw, &object_old_raw);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +
> >> +     ambient = mlx90632_preprocess_temp_amb(ambient_new_raw,
> >> +                                            ambient_old_raw, Gb);
> >> +     object = mlx90632_preprocess_temp_obj(object_new_raw,
> >> +                                           object_old_raw,
> >> +                                           ambient_new_raw,
> >> +                                           ambient_old_raw, Ka);
> >> +
> >> +     *val = mlx90632_calc_temp_object(object, ambient, Ea, Eb, Fa, Fb, Ga,
> >> +                                      Ha, Hb, data->emissivity);
> >> +     return 0;
> >> +}
> >> +
> >> +static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
> >> +{
> >> +     s32 ret;
> >> +     unsigned int read_tmp;
> >> +     s32 PT, PR, PG, PO;
> >> +     s16 Gb;
> >> +     s16 ambient_new_raw, ambient_old_raw;
> >> +
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_R, &PR);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_G, &PG);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_T, &PT);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_O, &PO);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
> >> +     if (ret < 0)
> >> +             return ret;
> >> +     Gb = (s16)read_tmp;
> >> +
> >> +     ret = mlx90632_read_ambient_raw(data->regmap, &ambient_new_raw,
> >> +                                     &ambient_old_raw);
> >> +     *val = mlx90632_calc_temp_ambient(ambient_new_raw, ambient_old_raw,
> >> +                                       PT, PR, PG, PO, Gb);
> >> +     return ret;
> >> +}
> >> +
> >> +static int mlx90632_read_raw(struct iio_dev *indio_dev,
> >> +                          struct iio_chan_spec const *channel, int *val,
> >> +                          int *val2, long mask)
> >> +{
> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
> >> +     int ret;
> >> +
> >> +     switch (mask) {
> >> +     case IIO_CHAN_INFO_PROCESSED:
> >> +             switch (channel->channel2) {
> >> +             case IIO_MOD_TEMP_AMBIENT:
> >> +                     ret = mlx90632_calc_ambient_dsp105(data, val);
> >> +                     if (ret < 0)
> >> +                             return ret;
> >> +                     return IIO_VAL_INT;
> >> +             case IIO_MOD_TEMP_OBJECT:
> >> +                     ret = mlx90632_calc_object_dsp105(data, val);
> >> +                     if (ret < 0)
> >> +                             return ret;
> >> +                     return IIO_VAL_INT;
> >> +             default:
> >> +                     return -EINVAL;
> >> +             }
> >> +     case IIO_CHAN_INFO_CALIBEMISSIVITY:
> >> +             if (data->emissivity == 1000) {
> >> +                     *val = 1;
> >> +                     *val2 = 0;
> >> +             } else {
> >> +                     *val = 0;
> >> +                     *val2 = data->emissivity;  
> > Odd given you are reporting as int + nano
> > this goes from 1.0 to 0.000000999 in one step?
> > Seems unlikely..  If it is true then a comment
> > is needed.
> >
> > The write is int + micro but this would still be wrong
> > without a factor of 1000.
> >  
> 
> In input (write) below I am adding factor of 1000. I do not know
> if resolution like that is needed, but you never know what they
> come up with in real life so I rather left some of the breating
> space.
The above still doesn't make much sense unless your range
is disjoint 0-0.000000999, 1.0 which would be surprising and
also doesn't correspond to the write.

> 
> >> +             }
> >> +             return IIO_VAL_INT_PLUS_NANO;
> >> +
> >> +     default:
> >> +             return -EINVAL;
> >> +     }
> >> +}
> >> +
> >> +static int mlx90632_write_raw(struct iio_dev *indio_dev,
> >> +                           struct iio_chan_spec const *channel, int val,
> >> +                           int val2, long mask)
> >> +{
> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
> >> +
> >> +     switch (mask) {
> >> +     case IIO_CHAN_INFO_CALIBEMISSIVITY:
> >> +             if (val < 0 || val2 < 0 || val > 1 ||
> >> +                 (val == 1 && val2 != 0))  
> >
> > I'd add a comment describing what this is doing.  I think it
> > is checking for 0-1.0 inclusive?
> >  
> 
> Yes, exactly. In case you set emissivity outside of range it should
> not change it and return EINVAL.
> 
> >> +                     return -EINVAL;
> >> +             data->emissivity = val * 1000 + val2 / 1000;
> >> +             return 0;
> >> +     default:
> >> +             return -EINVAL;
> >> +     }
> >> +}
> >> +
> >> +static const struct iio_chan_spec mlx90632_channels[] = {
> >> +     {
> >> +             .type = IIO_TEMP,
> >> +             .modified = 1,
> >> +             .channel2 = IIO_MOD_TEMP_AMBIENT,
> >> +             .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> >> +     },
> >> +     {
> >> +             .type = IIO_TEMP,
> >> +             .modified = 1,
> >> +             .channel2 = IIO_MOD_TEMP_OBJECT,
> >> +             .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> >> +                     BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
> >> +     },
> >> +};
> >> +
> >> +static const struct iio_info mlx90632_info = {
> >> +     .read_raw = mlx90632_read_raw,
> >> +     .write_raw = mlx90632_write_raw,
> >> +};
> >> +
> >> +#ifdef CONFIG_PM
> >> +static int mlx90632_sleep(struct mlx90632_data *data)
> >> +{
> >> +     dev_dbg(&data->client->dev, "Requesting sleep");
> >> +     return mlx90632_pwr_set_sleep_step(data->regmap);
> >> +}
> >> +
> >> +static int mlx90632_wakeup(struct mlx90632_data *data)
> >> +{
> >> +     dev_dbg(&data->client->dev, "Requesting wake-up");
> >> +     return mlx90632_pwr_continuous(data->regmap);
> >> +}
> >> +#endif
> >> +
> >> +static int mlx90632_probe(struct i2c_client *client,
> >> +                       const struct i2c_device_id *id)
> >> +{
> >> +     struct iio_dev *indio_dev;
> >> +     struct mlx90632_data *mlx90632;
> >> +     struct regmap *regmap;
> >> +     int ret;
> >> +     unsigned int read;
> >> +
> >> +     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*mlx90632));
> >> +     if (!indio_dev) {
> >> +             dev_err(&client->dev, "Failed to allocate device");
> >> +             return -ENOMEM;
> >> +     }
> >> +
> >> +     regmap = devm_regmap_init_i2c(client, &mlx90632_regmap);
> >> +     if (IS_ERR(regmap)) {
> >> +             ret = PTR_ERR(regmap);
> >> +             dev_err(&client->dev, "Failed to allocate regmap: %d\n", ret);
> >> +             return ret;
> >> +     }
> >> +
> >> +     mlx90632 = iio_priv(indio_dev);
> >> +     i2c_set_clientdata(client, indio_dev);
> >> +     mlx90632->client = client;
> >> +     mlx90632->regmap = regmap;
> >> +
> >> +     mutex_init(&mlx90632->lock);
> >> +     mlx90632_wakeup(mlx90632);
> >> +
> >> +     indio_dev->dev.parent = &client->dev;
> >> +     indio_dev->name = id->name;
> >> +     indio_dev->modes = INDIO_DIRECT_MODE;
> >> +     indio_dev->info = &mlx90632_info;
> >> +     indio_dev->channels = mlx90632_channels;
> >> +     indio_dev->num_channels = ARRAY_SIZE(mlx90632_channels);
> >> +
> >> +     ret = regmap_read(mlx90632->regmap, MLX90632_EE_VERSION, &read);
> >> +     if (ret < 0) {
> >> +             dev_err(&client->dev, "read of version failed: %d\n", ret);
> >> +             return ret;
> >> +     }
> >> +     if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_MEDICAL)) {  
> >
> > This is odd.  Why the bitwise and of what look to be two different things entirely?
> >  
> 
> If you look at how they are set (high vs low bits) you will see they
> are complimentary and
> prepared exactly for bitwise check. ID_MEDICAL might not be best name, but
> EEPROM_ID_MEDICAL was just too long. You read 16 bits and that is why
> lower 8 bits
> are in fact EEPROM_VERSION while higher 8 are ID of calibration. Since
> calculations
> are currently dependent on lower 8 bits, I left some of the wiggle
> space for future.
> In case we add another one in future, but I would rather have a strict
> check for this to
> avoid any kind of confusion what is supported.

Surely should be | then?

read == (0xff05 & 0x01ff)

read == (0x105)
So only 3 bits of overlap?

Definitely needs a comment to explain this int the code.

> 
> >> +             dev_dbg(&client->dev,
> >> +                     "Detected Medical EEPROM calibration %x", read);
> >> +     } else if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_CONSUMER)) {
> >> +             dev_dbg(&client->dev,
> >> +                     "Detected Consumer EEPROM calibration %x", read);
> >> +     } else {
> >> +             dev_err(&client->dev,
> >> +                     "Chip EEPROM version mismatch %x (expected %x)",
> >> +                     read, MLX90632_EEPROM_VERSION);
> >> +             return -EPROTONOSUPPORT;
> >> +     }
> >> +
> >> +     mlx90632->emissivity = 1000;
> >> +
> >> +     return devm_iio_device_register(&client->dev, indio_dev);  
> >
> > Don't use devm version.  You are (correctly) manually unwinding
> > this in the remove (as you have pm to deal with after removing the
> > interfaces).  This will result in a double free I think...
> > return iio_device_register is the way to go.
> >
> > I'm a bit confused that you don't seem to set up runtime pm anywhere...
> > I would assume we would be looking at autosuspend for a device
> > like this but it isn't enabled..
> >  
> 
> OK, will check how to use iio_device_register instead.
> 
> I did not do much of PM on device, so I can't really say. That is
> why autosuspend is not enabled.

If you are dropping the PM for now, then devm_iio_device_register is
fine, just drop the remove function entirely as it won't need to do
anything.
> 
> >> +}
> >> +
> >> +static int mlx90632_remove(struct i2c_client *client)
> >> +{
> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
> >> +
> >> +     iio_device_unregister(indio_dev);
> >> +
> >> +     pm_runtime_disable(&client->dev);
> >> +     if (!pm_runtime_status_suspended(&client->dev))
> >> +             mlx90632_sleep(data);
> >> +     pm_runtime_set_suspended(&client->dev);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static const struct i2c_device_id mlx90632_id[] = {
> >> +     { "mlx90632", 0 },
> >> +     { }
> >> +};
> >> +MODULE_DEVICE_TABLE(i2c, mlx90632_id);
> >> +
> >> +static const struct of_device_id mlx90632_of_match[] = {
> >> +     { .compatible = "melexis,mlx90632" },
> >> +     { }
> >> +};
> >> +MODULE_DEVICE_TABLE(of, mlx90632_of_match);
> >> +
> >> +#ifdef CONFIG_PM_SLEEP
> >> +static int mlx90632_pm_suspend(struct device *dev)
> >> +{
> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
> >> +
> >> +     if (pm_runtime_active(dev))
> >> +             return mlx90632_sleep(data);  
> >
> > I'm a little confused as to why, if the device is powered
> > up fully and a suspend comes in we have to do less than we do
> > in runtime pm case.
> >
> > Am I missing something?
> >  
> 
> I think I have mostly tested runtime pm case, so this might have
> been missed. I did get wrong results if I did not mark regcache as dirty.
> 
> I will just remove the whole PM thing to start with and add it up later, OK?

Makes sense.

> 
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int mlx90632_pm_resume(struct device *dev)
> >> +{
> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
> >> +     int err;
> >> +
> >> +     err = mlx90632_wakeup(data);
> >> +     if (err < 0)
> >> +             return err;
> >> +
> >> +     pm_runtime_disable(dev);
> >> +     pm_runtime_set_active(dev);
> >> +     pm_runtime_enable(dev);
> >> +
> >> +     return 0;
> >> +}
> >> +#endif
> >> +
> >> +#ifdef CONFIG_PM
> >> +static int mlx90632_pm_runtime_suspend(struct device *dev)
> >> +{
> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> >> +     struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
> >> +
> >> +     regcache_sync(mlx90632->regmap);
> >> +
> >> +     return mlx90632_sleep(mlx90632);
> >> +}
> >> +
> >> +static int mlx90632_pm_runtime_resume(struct device *dev)
> >> +{
> >> +     s32 ret;
> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> >> +     struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
> >> +
> >> +     regcache_mark_dirty(mlx90632->regmap);
> >> +     regcache_cache_only(mlx90632->regmap, false);
> >> +     ret = regcache_sync(mlx90632->regmap);
> >> +     if (ret < 0) {
> >> +             dev_err(dev, "Failed to sync regmap registers: %d\n", ret);
> >> +             return ret;
> >> +     }
> >> +
> >> +     return mlx90632_wakeup(mlx90632);
> >> +}
> >> +#endif
> >> +
> >> +static const struct dev_pm_ops mlx90632_pm_ops = {
> >> +     SET_SYSTEM_SLEEP_PM_OPS(mlx90632_pm_suspend, mlx90632_pm_resume)
> >> +     SET_RUNTIME_PM_OPS(mlx90632_pm_runtime_suspend,
> >> +                        mlx90632_pm_runtime_resume, NULL)
> >> +};
> >> +
> >> +static struct i2c_driver mlx90632_driver = {
> >> +     .driver = {
> >> +             .name   = "mlx90632",
> >> +             .of_match_table = mlx90632_of_match,
> >> +             .pm     = &mlx90632_pm_ops,
> >> +     },
> >> +     .probe = mlx90632_probe,
> >> +     .remove = mlx90632_remove,
> >> +     .id_table = mlx90632_id,
> >> +};
> >> +module_i2c_driver(mlx90632_driver);
> >> +
> >> +MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
> >> +MODULE_DESCRIPTION("Melexis MLX90632 contactless Infra Red temperature sensor driver");
> >> +MODULE_LICENSE("GPL v2");  
> >
> > --
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> > the body of a message to majordomo@vger.kernel.org
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Crt Mori Dec. 5, 2017, 3:59 p.m. UTC | #4
Hi Jonathan,
I already sent v2 of the driver with some of your comments in. Will
fix remainder in v3 - I am
meanwhile also interested what responses I will get with including
into int_sqrt().

Thanks for comments.

Best regards,
Crt

On 5 December 2017 at 12:23, Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
> On Sat, 2 Dec 2017 21:30:54 +0100
> Crt Mori <cmo@melexis.com> wrote:
>
>> Hi Jonathan,
>> Definitely did not think there will be so many comments inside, but I
>> expected few of them indeed.
>>
>> See my replies inside.
>>
>> On 2 December 2017 at 15:33, Jonathan Cameron <jic23@kernel.org> wrote:
>> > On Wed, 29 Nov 2017 23:07:49 +0100
>> > Crt Mori <cmo@melexis.com> wrote:
>> >
>> >> Melexis has just released Infra Red temperature sensor MLX90632 used
>> >> for contact-less temperature measurement. Driver provides basic
>> >> functionality for reporting object (and ambient) temperature with
>> >> support for object emissivity.
>> >>
>> >> Signed-off-by: Crt Mori <cmo@melexis.com>
>> >
>> > Various comments inline.
>> >
>> >> ---
>> >>  MAINTAINERS                        |   7 +
>> >>  drivers/iio/temperature/Kconfig    |  12 +
>> >>  drivers/iio/temperature/Makefile   |   1 +
>> >>  drivers/iio/temperature/mlx90632.c | 802 +++++++++++++++++++++++++++++++++++++
>> >>  4 files changed, 822 insertions(+)
>> >>  create mode 100644 drivers/iio/temperature/mlx90632.c
>> >>
>> >> diff --git a/MAINTAINERS b/MAINTAINERS
>> >> index 2d3d750b19c0..81aec02b08b8 100644
>> >> --- a/MAINTAINERS
>> >> +++ b/MAINTAINERS
>> >> @@ -8690,6 +8690,13 @@ W:     http://www.melexis.com
>> >>  S:   Supported
>> >>  F:   drivers/iio/temperature/mlx90614.c
>> >>
>> >> +MELEXIS MLX90632 DRIVER
>> >> +M:   Crt Mori <cmo@melexis.com>
>> >> +L:   linux-iio@vger.kernel.org
>> >> +W:   http://www.melexis.com
>> >> +S:   Supported
>> >> +F:   drivers/iio/temperature/mlx90632.c
>> >> +
>> >>  MELFAS MIP4 TOUCHSCREEN DRIVER
>> >>  M:   Sangwon Jee <jeesw@melfas.com>
>> >>  W:   http://www.melfas.com
>> >> diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
>> >> index 5378976d6d27..82e4a62745e2 100644
>> >> --- a/drivers/iio/temperature/Kconfig
>> >> +++ b/drivers/iio/temperature/Kconfig
>> >> @@ -43,6 +43,18 @@ config MLX90614
>> >>         This driver can also be built as a module. If so, the module will
>> >>         be called mlx90614.
>> >>
>> >> +config MLX90632
>> >> +     tristate "MLX90632 contact-less infrared sensor with medical accuracy"
>> >> +     depends on I2C
>> >> +     select REGMAP_I2C
>> >> +     help
>> >> +       If you say yes here you get support for the Melexis
>> >> +       MLX90632 contact-less infrared sensor with medical accuracy
>> >> +       connected with I2C.
>> >> +
>> >> +       This driver can also be built as a module. If so, the module will
>> >> +       be called mlx90632.
>> >> +
>> >>  config TMP006
>> >>       tristate "TMP006 infrared thermopile sensor"
>> >>       depends on I2C
>> >> diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
>> >> index ad1d668de546..44644fe01bc9 100644
>> >> --- a/drivers/iio/temperature/Makefile
>> >> +++ b/drivers/iio/temperature/Makefile
>> >> @@ -5,6 +5,7 @@
>> >>  obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
>> >>  obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
>> >>  obj-$(CONFIG_MLX90614) += mlx90614.o
>> >> +obj-$(CONFIG_MLX90632) += mlx90632.o
>> >>  obj-$(CONFIG_TMP006) += tmp006.o
>> >>  obj-$(CONFIG_TMP007) += tmp007.o
>> >>  obj-$(CONFIG_TSYS01) += tsys01.o
>> >> diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
>> >> new file mode 100644
>> >> index 000000000000..05c7d943e504
>> >> --- /dev/null
>> >> +++ b/drivers/iio/temperature/mlx90632.c
>> >> @@ -0,0 +1,802 @@
>> >> +/*
>> >> + * mlx90632.c - Melexis MLX90632 contactless IR temperature sensor
>> >> + *
>> >> + * Copyright (c) 2017 Melexis <cmo@melexis.com>
>> >> + *
>> >> + * This file is subject to the terms and conditions of version 2 of
>> >> + * the GNU General Public License.  See the file COPYING in the main
>> >> + * directory of this archive for more details.
>> >> + *
>> >> + * Driver for the Melexis MLX90632 I2C 16-bit IR thermopile sensor
>> >> + */
>> >> +#include <asm/byteorder.h>
>> > Don't think this should ever be included in a driver.
>> > What do you need it for?
>> >
>> >> +#include <linux/delay.h>
>> >> +#include <linux/err.h>
>> >> +#include <linux/gpio/consumer.h>
>> >> +#include <linux/i2c.h>
>> >> +#include <linux/kernel.h>
>> >> +#include <linux/module.h>
>> >> +#include <linux/math64.h>
>> >> +#include <linux/of.h>
>> >> +#include <linux/pm_runtime.h>
>> >> +#include <linux/regmap.h>
>> >> +#include <linux/unaligned/be_byteshift.h>
>> > why?
>> >
>> >> +
>> >> +#include <linux/iio/iio.h>
>> >> +#include <linux/iio/sysfs.h>
>> >> +
>> >> +/* Memory sections addresses */
>> >> +#define MLX90632_ADDR_RAM    0x4000 /* Start address of ram */
>> >> +#define MLX90632_ADDR_EEPROM 0x2480 /* Start address of user eeprom */
>> >> +
>> >> +/* EEPROM addresses - used at startup */
>> >> +#define MLX90632_EE_CTRL     0x24d4 /* Control register initial value */
>> >> +#define MLX90632_EE_I2C_ADDR 0x24d5 /* I2C address register initial value */
>> >> +#define MLX90632_EE_VERSION  0x240b /* EEPROM version reg address */
>> >> +#define MLX90632_EE_P_R              0x240c /* P_R calibration register 32bit */
>> >> +#define MLX90632_EE_P_G              0x240e /* P_G calibration register 32bit */
>> >> +#define MLX90632_EE_P_T              0x2410 /* P_T calibration register 32bit */
>> >> +#define MLX90632_EE_P_O              0x2412 /* P_O calibration register 32bit */
>> >> +#define MLX90632_EE_Aa               0x2414 /* Aa calibration register 32bit */
>> >> +#define MLX90632_EE_Ab               0x2416 /* Ab calibration register 32bit */
>> >> +#define MLX90632_EE_Ba               0x2418 /* Ba calibration register 32bit */
>> >> +#define MLX90632_EE_Bb               0x241a /* Bb calibration register 32bit */
>> >> +#define MLX90632_EE_Ca               0x241c /* Ca calibration register 32bit */
>> >> +#define MLX90632_EE_Cb               0x241e /* Cb calibration register 32bit */
>> >> +#define MLX90632_EE_Da               0x2420 /* Da calibration register 32bit */
>> >> +#define MLX90632_EE_Db               0x2422 /* Db calibration register 32bit */
>> >> +#define MLX90632_EE_Ea               0x2424 /* Ea calibration register 32bit */
>> >> +#define MLX90632_EE_Eb               0x2426 /* Eb calibration register 32bit */
>> >> +#define MLX90632_EE_Fa               0x2428 /* Fa calibration register 32bit */
>> >> +#define MLX90632_EE_Fb               0x242a /* Fb calibration register 32bit */
>> >> +#define MLX90632_EE_Ga               0x242c /* Ga calibration register 32bit */
>> >> +
>> >> +#define MLX90632_EE_Gb               0x242e /* Gb calibration register 16bit */
>> >> +#define MLX90632_EE_Ka               0x242f /* Ka calibration register 16bit */
>> >> +
>> >> +#define MLX90632_EE_Ha               0x2481 /* Ha customer calib value reg 16bit */
>> >> +#define MLX90632_EE_Hb               0x2482 /* Hb customer calib value reg 16bit */
>> >> +
>> >> +/* Register addresses - volatile */
>> >> +#define MLX90632_REG_I2C_ADDR        0x3000 /* Chip I2C address register */
>> >> +
>> >> +/* Control register address - volatile */
>> >> +#define MLX90632_REG_CONTROL 0x3001 /* Control Register address */
>> >> +#define   MLX90632_CFG_PWR_MASK              GENMASK(2, 1) /* PowerMode Mask */
>> >> +/* PowerModes statuses */
>> >> +#define MLX90632_PWR_STATUS(ctrl_val) (ctrl_val << 1)
>> >> +#define MLX90632_PWR_STATUS_HALT MLX90632_PWR_STATUS(0) /* hold */
>> >> +#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step*/
>> >> +#define MLX90632_PWR_STATUS_STEP MLX90632_PWR_STATUS(2) /* step */
>> >> +#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous*/
>> >> +
>> >> +/* Device status register - volatile */
>> >> +#define MLX90632_REG_STATUS  0x3fff /* Device status register */
>> >> +#define   MLX90632_STAT_BUSY         BIT(10) /* Device busy indicator */
>> >> +#define   MLX90632_STAT_EE_BUSY              BIT(9) /* EEPROM busy indicator */
>> >> +#define   MLX90632_STAT_BRST         BIT(8) /* Brown out reset indicator */
>> >> +#define   MLX90632_STAT_CYCLE_POS    GENMASK(6, 2) /* Data position */
>> >> +#define   MLX90632_STAT_DATA_RDY     BIT(0) /* Data ready indicator */
>> >> +
>> >> +/* RAM_MEAS address-es for each channel */
>> >> +#define MLX90632_RAM_1(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num)
>> >> +#define MLX90632_RAM_2(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num + 1)
>> >> +#define MLX90632_RAM_3(meas_num)     (MLX90632_ADDR_RAM + 3 * meas_num + 2)
>> >> +
>> >> +/* Magic constants */
>> >> +#define MLX90632_EEPROM_VERSION      0xff05 /* EEPROM DSP version for constants */
>> >> +#define MLX90632_ID_MEDICAL  0x01ff /* EEPROM Medical device id */
>> >> +#define MLX90632_ID_CONSUMER 0x02ff /* EEPROM Consumer device id */
>> >> +#define MLX90632_EEPROM_WRITE_KEY 0x554C /* EEPROM write key 0x55 and 0x4c */
>> >> +#define MLX90632_RESET_CMD   0x0006 /* Reset sensor (address or global) */
>> >> +#define MLX90632_REF_12              12LL /**< ResCtrlRef value of Ch 1 or Ch 2 */
>> >> +#define MLX90632_REF_3               12LL /**< ResCtrlRef value of Channel 3 */
>> >> +
>> >> +#define TENTO3                       1000LL
>> >> +#define TENTO4                       10000LL
>> >> +#define TENTO5                       100000LL
>> >> +#define TENTO6                       1000000LL
>> >> +#define TENTO7                       10000000LL
>> >> +#define TENTO10                      10000000000LL
>> >> +#define TENTO12                      1000000000000LL
>> > Umm. The numbers describe the constants rather better than the defines ;)
>> > Just use the numbers if you need them!
>> >
>>
>> This is way shorter (line length) and more readable in my opinion.
>> Also writing 12 times 0 is error prone :D
>
> Needs care but I really don't like these constants.
>
>>
>> >> +
>> >> +struct mlx90632_data {
>> >> +     struct i2c_client *client;
>> >> +     struct mutex lock; /* Multiple reads for single measurement */
>> >> +     struct regmap *regmap;
>> >> +     u16 emissivity;
>> >> +};
>> >> +
>> >> +static const struct regmap_range mlx90632_volatile_reg_range[] = {
>> >> +     regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
>> >> +     regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
>> >> +     regmap_reg_range(MLX90632_RAM_1(0),
>> >> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
>> >> +};
>> >> +
>> >> +static const struct regmap_access_table mlx90632_volatile_regs_tbl = {
>> >> +     .yes_ranges = mlx90632_volatile_reg_range,
>> >> +     .n_yes_ranges = ARRAY_SIZE(mlx90632_volatile_reg_range),
>> >> +};
>> >> +
>> >> +static const struct regmap_range mlx90632_read_reg_range[] = {
>> >> +     regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
>> >> +     regmap_reg_range(MLX90632_EE_CTRL, MLX90632_EE_I2C_ADDR),
>> >> +     regmap_reg_range(MLX90632_EE_Ha, MLX90632_EE_Hb),
>> >> +     regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
>> >> +     regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
>> >> +     regmap_reg_range(MLX90632_RAM_1(0),
>> >> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
>> >> +};
>> >> +
>> >> +static const struct regmap_access_table mlx90632_readable_regs_tbl = {
>> >> +     .yes_ranges = mlx90632_read_reg_range,
>> >> +     .n_yes_ranges = ARRAY_SIZE(mlx90632_read_reg_range),
>> >> +};
>> >> +
>> >> +static const struct regmap_range mlx90632_no_write_reg_range[] = {
>> >> +     regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
>> >> +     regmap_reg_range(MLX90632_RAM_1(0),
>> >> +                      MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
>> >> +};
>> >> +
>> >> +static const struct regmap_access_table mlx90632_writeable_regs_tbl = {
>> >> +     .no_ranges = mlx90632_no_write_reg_range,
>> >> +     .n_no_ranges = ARRAY_SIZE(mlx90632_no_write_reg_range),
>> >> +};
>> >> +
>> >> +static const struct regmap_config mlx90632_regmap = {
>> >> +     .reg_bits = 16,
>> >> +     .val_bits = 16,
>> >> +
>> >> +     .volatile_table = &mlx90632_volatile_regs_tbl,
>> >> +     .rd_table = &mlx90632_readable_regs_tbl,
>> >> +     .wr_table = &mlx90632_writeable_regs_tbl,
>> >> +
>> >> +     .use_single_rw = true,
>> >> +     .reg_format_endian = REGMAP_ENDIAN_BIG,
>> >> +     .val_format_endian = REGMAP_ENDIAN_BIG,
>> >> +     .cache_type = REGCACHE_RBTREE,
>> >> +};
>> >> +
>> >> +static u64 mlx90632_int_sqrt(u64 x)
>> >> +{
>> >> +     u64 b, m, y = 0;
>> >> +
>> >> +     if (BITS_PER_LONG != 32)
>> >> +             return int_sqrt(x);
>> >
>> > needs a comment on why...
>> > Ideally propose a standard 64 bit routine if one is needed for
>> > 32 bit machines.
>> >
>>
>> Problem is that int_sqrt is not strongly typed. That means 64 bit
>> number gets truncated to 32bit on 32bit machine as you mentioned
>> and that caused quite many headaches in my testing (worked on
>> mobile phone, but not on beaglebone black).  This solution is just
>> stronger typing of int_sqrt function.
>>
>> If you think I should put it onto math.h as a patch I can try it.
>
> Sure, let's see if that goes anywhere.  Seems the right approach to me.
>
>>
>> >> +
>> >> +     if (x <= 1)
>> >> +             return x;
>> >> +
>> >> +     m = 1ULL << (64 - 2);
>> >> +     while (m != 0) {
>> >> +             b = y + m;
>> >> +             y >>= 1;
>> >> +
>> >> +             if (x >= b) {
>> >> +                     x -= b;
>> >> +                     y += m;
>> >> +             }
>> >> +             m >>= 2;
>> >> +     }
>> >> +     return y;
>> >> +}
>> >> +
>> >> +static s32 mlx90632_pwr_set_sleep_step(struct regmap *regmap)
>> >> +{
>> >> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
>> >> +                               MLX90632_CFG_PWR_MASK,
>> >> +                               MLX90632_PWR_STATUS_SLEEP_STEP);
>> >> +}
>> >> +
>> >> +static s32 mlx90632_pwr_set_step(struct regmap *regmap)
>> >> +{
>> >> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
>> >> +                               MLX90632_CFG_PWR_MASK,
>> >> +                               MLX90632_PWR_STATUS_STEP);
>> >> +}
>> >> +
>> >> +static s32 mlx90632_pwr_continuous(struct regmap *regmap)
>> >> +{
>> >> +     return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
>> >> +                               MLX90632_CFG_PWR_MASK,
>> >> +                               MLX90632_PWR_STATUS_CONTINUOUS);
>> >> +}
>> >> +
>> >> +static int mlx90632_start_measurement(struct mlx90632_data *data)
>> >
>> > Looks superficially to me like this is actually waiting for a reading
>> > to complete rather than just starting it?  If so change the name
>> > to reflect that.
>> >
>>
>> ok
>>
>> >> +{
>> >> +     int ret, tries = 100;
>> >> +     unsigned int reg_status;
>> >> +
>> >> +     ret = regmap_update_bits(data->regmap, MLX90632_REG_STATUS,
>> >> +                              MLX90632_STAT_DATA_RDY, 0);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +
>> >> +     while (tries-- > 0) {
>> >> +             ret = regmap_read(data->regmap, MLX90632_REG_STATUS,
>> >> +                               &reg_status);
>> >> +             if (ret < 0)
>> >> +                     return ret;
>> >> +             if (reg_status & MLX90632_STAT_DATA_RDY)
>> >> +                     break;
>> >> +             usleep_range(10000, 11000);
>> >> +     }
>> >> +
>> >> +     if (tries < 0) {
>> >> +             dev_err(&data->client->dev, "data not ready");
>> >> +             return -ETIMEDOUT;
>> >> +     }
>> >> +
>> >> +     return (reg_status & MLX90632_STAT_CYCLE_POS) >> 2;
>> >
>> > This is a non obvious return value so I would suggest adding
>> > some documentation to say what is going on here..
>> >
>>
>> Yes, it is indeed.
>>
>> >> +}
>> >> +
>> >> +static int mlx9032_channel_new_select(int ret, uint8_t *channel_new,
>> >> +                                   uint8_t *channel_old)
>> >
>> > don't use ret as a name for a variable being passed in.  Rather
>> > confusing!
>> >
>>
>> OK. I think I should just copy setting of channel_old and new in the
>> only spot it is used.
>>
>> >> +{
>> >> +     if (ret == 1) {
>> >> +             *channel_new = 1;
>> >> +             *channel_old = 2;
>> >> +     } else if (ret == 2) {
>> >> +             *channel_new = 2;
>> >> +             *channel_old = 1;
>> >> +     } else {
>> >> +             return ret;
>> >> +     }
>> >> +     return 0;
>> > Can't get here...
>> >
>>
>> Not true. You get here in every example other than else where channel_new
>> and channel_old are successfully set. but I agree there is a bug in case ret=0
>> when it will return 0, but it will not set channels.
>
> Ah good point, I missed that. I would do it as a switch with direct returns.
>

Yes, that is already changed to switch in v2.

>>
>> >> +}
>> >> +
>> >> +static int mlx90632_read_ambient_raw(struct regmap *regmap,
>> >> +                                  s16 *ambient_new_raw, s16 *ambient_old_raw)
>> >> +{
>> >> +     int ret;
>> >> +     unsigned int read_tmp;
>> >> +
>> >> +     ret = regmap_read(regmap, MLX90632_RAM_3(1), &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     *ambient_new_raw = (s16)read_tmp;
>> >> +
>> >> +     ret = regmap_read(regmap, MLX90632_RAM_3(2), &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     *ambient_old_raw = (s16)read_tmp;
>> >> +
>> >> +     return ret;
>> >> +}
>> >> +
>> >> +static int mlx90632_read_object_raw(struct regmap *regmap,
>> >> +                                 int start_measurement_ret,
>> >> +                                 s16 *object_new_raw, s16 *object_old_raw)
>> >> +{
>> >> +     int ret;
>> >> +     unsigned int read_tmp;
>> >> +     s16 read;
>> >> +     u8 channel = 0;
>> >> +     u8 channel_old = 0;
>> >> +
>> >> +     ret = mlx90632_channel_new_select(start_measurement_ret, &channel,
>> >> +                                       &channel_old);
>> >> +     if (ret != 0)
>> >> +             return ret;
>> >> +
>> >> +     ret = regmap_read(regmap, MLX90632_RAM_2(channel), &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +
>> >> +     read = (s16)read_tmp;
>> >> +
>> >> +     ret = regmap_read(regmap, MLX90632_RAM_1(channel), &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     *object_new_raw = (read + (s16)read_tmp) / 2;
>> >> +
>> >> +     ret = regmap_read(regmap, MLX90632_RAM_2(channel_old), &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     read = (s16)read_tmp;
>> >> +
>> >> +     ret = regmap_read(regmap, MLX90632_RAM_1(channel_old), &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     *object_old_raw = (read + (s16)read_tmp) / 2;
>> >> +
>> >> +     return ret;
>> >> +}
>> >> +
>> >> +static int mlx90632_read_all_channel(struct mlx90632_data *data,
>> >> +                                  s16 *ambient_new_raw, s16 *ambient_old_raw,
>> >> +                                  s16 *object_new_raw, s16 *object_old_raw)
>> >> +{
>> >> +     s32 ret, tm_ret;
>> >> +
>> >> +     mutex_lock(&data->lock);
>> >> +     tm_ret = mlx90632_start_measurement(data);
>> >> +     if (tm_ret >= 0) {
>> >> +             ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
>> >> +                                             ambient_old_raw);
>> >> +             if (ret >= 0) {
>> >> +                     ret = mlx90632_read_object_raw(data->regmap, tm_ret,
>> >> +                                                    object_new_raw,
>> >> +                                                    object_old_raw);
>> >> +             }
>> >> +     } else {
>> >> +             ret = tm_ret;
>> >> +     }
>> > Use something cleaner like
>> >         mutex_lock(&data->lock);
>> >         ret = mlx90632_start_measurement(data);
>> >         if (ret < 0)
>> >                 goto unlock;
>> >         ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
>> >                                         ambient_old_raw);
>> >         if (ret < 0)
>> >                 goto unlock;
>> >
>> >         ret = mlx90632_read_object_raw(data->regmap, tm_ret,
>> >                                        object_new_raw,
>> >                                        object_old_raw);
>> > unlock:
>>
>> Ok sorry, professional deformation (goto).
>>
>> >> +     mutex_unlock(&data->lock);
>> >> +     return ret;
>> >> +}
>> >> +
>> >> +static int mlx90632_read_ee_register(struct regmap *regmap, u16 reg_lsb,
>> >> +                                  s32 *reg_value)
>> >> +{
>> >> +     s32 ret;
>> >> +     unsigned int read;
>> >> +     __le32 value;
>> >> +
>> >> +     ret = regmap_read(regmap, reg_lsb, &read);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +
>> >> +     value = cpu_to_le32(read);
>> >
>> > Why would you be converting to le32 to then do
>> > calculations in here using it at cpu endianness?
>> > (guessing you want le32_to_cpu..)
>> >
>> > hmm isn't any relevant endian conversion wrapped up in regmap
>> > anyway?
>> >
>>
>> Regmap reads 16 bit values, but some values are 32 bit. To avoid CPU
>> endianess affecting this, I am putting it to known time and shift values.
>> This way I ensured it is working on any CPU. le32_to_cpu is in return value.
>>
>
> I'm far from convinced this is a good idea. I would ensure all values
> are in cpu endianness before combining them based on the read order
> (which is endian independant)
>

OK, I see the point. Will try it and send v3 (which will be needed anyway).

>> >> +
>> >> +     ret = regmap_read(regmap, reg_lsb + 1, &read);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +
>> >> +     value = (cpu_to_le32(read) << 16) | (value & 0xffff);
>> >> +
>> >> +     *reg_value = le32_to_cpu(value);
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static s64 mlx90632_preprocess_temp_amb(s16 ambient_new_raw,
>> >> +                                     s16 ambient_old_raw, s16 Gb)
>> >> +{
>> >> +     s64 VR_Ta, kGb, tmp;
>> >> +
>> >> +     kGb = ((s64)Gb * TENTO3) >> 10ULL;
>> >> +     VR_Ta = (s64)ambient_old_raw * TENTO6 +
>> >> +             kGb * div64_s64(((s64)ambient_new_raw * TENTO3),
>> >> +                     (MLX90632_REF_3));
>> >> +     tmp = div64_s64(
>> >> +                      div64_s64(((s64)ambient_new_raw * TENTO12),
>> >> +                                (MLX90632_REF_3)), VR_Ta);
>> >> +     return div64_s64(tmp << 19ULL, TENTO3);
>> >> +}
>> >> +
>> >> +static s64 mlx90632_preprocess_temp_obj(s16 object_new_raw, s16 object_old_raw,
>> >> +                                     s16 ambient_new_raw,
>> >> +                                     s16 ambient_old_raw, s16 Ka)
>> >> +{
>> >> +     s64 VR_IR, kKa, tmp;
>> >> +
>> >> +     kKa = ((s64)Ka * TENTO3) >> 10ULL;
>> >> +     VR_IR = (s64)ambient_old_raw * TENTO6 +
>> >> +             kKa * div64_s64(((s64)ambient_new_raw * TENTO3),
>> >> +                     (MLX90632_REF_3));
>> >> +     tmp = div64_s64(
>> >> +                     div64_s64(((s64)((object_new_raw + object_old_raw) / 2)
>> >> +                                * TENTO12), (MLX90632_REF_12)), VR_IR);
>> >> +     return div64_s64(tmp << 19ULL), TENTO3);
>> >> +}
>> >> +
>> >> +static s32 mlx90632_calc_temp_ambient(s16 ambient_new_raw, s16 ambient_old_raw,
>> >> +                                   s32 P_T, s32 P_R, s32 P_G, s32 P_O,
>> >> +                                   s16 Gb)
>> >> +{
>> >> +     s64 Asub, Bsub, Ablock, Bblock, Cblock, AMB, sum;
>> >> +
>> >> +     AMB = mlx90632_preprocess_temp_amb(ambient_new_raw, ambient_old_raw,
>> >> +                                        Gb);
>> >> +     Asub = ((s64)P_T * TENTO10) >> 44ULL;
>> >> +     Bsub = AMB - (((s64)P_R * TENTO3) >> 8ULL);
>> >> +     Ablock = Asub * (Bsub * Bsub);
>> >> +     Bblock = (div64_s64(Bsub * TENTO7, P_G)) << 20ULL;
>> >> +     Cblock = ((s64)P_O * TENTO10) >> 8ULL;
>> >> +
>> >> +     sum = div64_s64(Ablock, TENTO6) + Bblock + Cblock;
>> >> +
>> >> +     return div64_s64(sum, TENTO7);
>> >> +}
>> >> +
>> >> +static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
>> >> +                                            s64 TAdut, s32 Fa, s32 Fb,
>> >> +                                            s32 Ga, s16 Ha, s16 Hb,
>> >> +                                            u16 emissivity)
>> >> +{
>> >> +     s64 calcedKsTO, calcedKsTA, ir_Alpha, TAdut4, Alpha_corr;
>> >> +     s64 Ha_customer, Hb_customer;
>> >> +
>> >> +     Ha_customer = ((s64)Ha * TENTO6) >> 14ULL;
>> >> +     Hb_customer = ((s64)Hb * 100) >> 10ULL;
>> >> +
>> >> +     calcedKsTO = ((s64)((s64)Ga * (prev_object_temp - 25 * TENTO3)
>> >> +                          * TENTO3)) >> 36LL;
>> >> +     calcedKsTA = ((s64)(Fb * (TAdut - 25 * TENTO6))) >> 36LL;
>> >> +     Alpha_corr = div64_s64((((s64)(Fa * TENTO10) >> 46LL) * Ha_customer),
>> >> +                            TENTO3);
>> >> +     Alpha_corr *= ((s64)(1 * TENTO6 + calcedKsTO + calcedKsTA));
>> >> +     Alpha_corr = emissivity * div64_s64(Alpha_corr, TENTO5);
>> >> +     Alpha_corr = div64_s64(Alpha_corr, TENTO3);
>> >> +     ir_Alpha = div64_s64((s64)object * TENTO7, Alpha_corr);
>> >> +     TAdut4 = (div64_s64(TAdut, TENTO4) + 27315) *
>> >> +             (div64_s64(TAdut, TENTO4) + 27315) *
>> >> +             (div64_s64(TAdut, TENTO4)  + 27315) *
>> >> +             (div64_s64(TAdut, TENTO4) + 27315);
>> >> +
>> >> +     return (mlx90632_int_sqrt(
>> >> +                      mlx90632_int_sqrt(ir_Alpha * TENTO12 + TAdut4)
>> >> +                     ) - 27315 - Hb_customer) * 10;
>> >> +}
>> >> +
>> >> +static s32 mlx90632_calc_temp_object(s64 object, s64 ambient, s32 Ea, s32 Eb,
>> >> +                                  s32 Fa, s32 Fb, s32 Ga, s16 Ha, s16 Hb,
>> >> +                                  u16 tmp_emi)
>> >> +{
>> >> +     s64 kTA, kTA0, TAdut;
>> >> +     s64 temp = 25000;
>> >> +     s8 i;
>> >> +
>> >> +     kTA = (Ea * TENTO3) >> 16LL;
>> >> +     kTA0 = (Eb * TENTO3) >> 8LL;
>> >> +     TAdut = div64_s64(((ambient - kTA0) * TENTO6), kTA) + 25 * TENTO6;
>> >> +
>> >> +     for (i = 0; i < 5; ++i) {
>> > comment on why iterations are needed would be good here.
>>
>> This is described in datasheet (the whole calculation). Will add
>> explanatory comment.
>>
>> >> +             temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut,
>> >> +                                                        Fa, Fb, Ga, Ha, Hb,
>> >> +                                                        tmp_emi);
>> >> +     }
>> >> +     return temp;
>> >> +}
>> >> +
>> >> +static int mlx90632_calc_object_dsp105(struct mlx90632_data *data, int *val)
>> >> +{
>> >> +     s32 ret;
>> >> +     s32 Ea, Eb, Fa, Fb, Ga;
>> >> +     unsigned int read_tmp;
>> >> +     s16 Ha, Hb, Gb, Ka;
>> >> +     s16 ambient_new_raw, ambient_old_raw, object_new_raw, object_old_raw;
>> >> +     s64 object, ambient;
>> >> +
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ea, &Ea);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Eb, &Eb);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fa, &Fa);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fb, &Fb);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ga, &Ga);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Ha, &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     Ha = (s16)read_tmp;
>> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Hb, &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     Hb = (s16)read_tmp;
>> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     Gb = (s16)read_tmp;
>> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Ka, &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     Ka = (s16)read_tmp;
>> >> +
>> >> +     ret = mlx90632_read_all_channel(data,
>> >> +                                     &ambient_new_raw, &ambient_old_raw,
>> >> +                                     &object_new_raw, &object_old_raw);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +
>> >> +     ambient = mlx90632_preprocess_temp_amb(ambient_new_raw,
>> >> +                                            ambient_old_raw, Gb);
>> >> +     object = mlx90632_preprocess_temp_obj(object_new_raw,
>> >> +                                           object_old_raw,
>> >> +                                           ambient_new_raw,
>> >> +                                           ambient_old_raw, Ka);
>> >> +
>> >> +     *val = mlx90632_calc_temp_object(object, ambient, Ea, Eb, Fa, Fb, Ga,
>> >> +                                      Ha, Hb, data->emissivity);
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
>> >> +{
>> >> +     s32 ret;
>> >> +     unsigned int read_tmp;
>> >> +     s32 PT, PR, PG, PO;
>> >> +     s16 Gb;
>> >> +     s16 ambient_new_raw, ambient_old_raw;
>> >> +
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_R, &PR);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_G, &PG);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_T, &PT);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_O, &PO);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
>> >> +     if (ret < 0)
>> >> +             return ret;
>> >> +     Gb = (s16)read_tmp;
>> >> +
>> >> +     ret = mlx90632_read_ambient_raw(data->regmap, &ambient_new_raw,
>> >> +                                     &ambient_old_raw);
>> >> +     *val = mlx90632_calc_temp_ambient(ambient_new_raw, ambient_old_raw,
>> >> +                                       PT, PR, PG, PO, Gb);
>> >> +     return ret;
>> >> +}
>> >> +
>> >> +static int mlx90632_read_raw(struct iio_dev *indio_dev,
>> >> +                          struct iio_chan_spec const *channel, int *val,
>> >> +                          int *val2, long mask)
>> >> +{
>> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> >> +     int ret;
>> >> +
>> >> +     switch (mask) {
>> >> +     case IIO_CHAN_INFO_PROCESSED:
>> >> +             switch (channel->channel2) {
>> >> +             case IIO_MOD_TEMP_AMBIENT:
>> >> +                     ret = mlx90632_calc_ambient_dsp105(data, val);
>> >> +                     if (ret < 0)
>> >> +                             return ret;
>> >> +                     return IIO_VAL_INT;
>> >> +             case IIO_MOD_TEMP_OBJECT:
>> >> +                     ret = mlx90632_calc_object_dsp105(data, val);
>> >> +                     if (ret < 0)
>> >> +                             return ret;
>> >> +                     return IIO_VAL_INT;
>> >> +             default:
>> >> +                     return -EINVAL;
>> >> +             }
>> >> +     case IIO_CHAN_INFO_CALIBEMISSIVITY:
>> >> +             if (data->emissivity == 1000) {
>> >> +                     *val = 1;
>> >> +                     *val2 = 0;
>> >> +             } else {
>> >> +                     *val = 0;
>> >> +                     *val2 = data->emissivity;
>> > Odd given you are reporting as int + nano
>> > this goes from 1.0 to 0.000000999 in one step?
>> > Seems unlikely..  If it is true then a comment
>> > is needed.
>> >
>> > The write is int + micro but this would still be wrong
>> > without a factor of 1000.
>> >
>>
>> In input (write) below I am adding factor of 1000. I do not know
>> if resolution like that is needed, but you never know what they
>> come up with in real life so I rather left some of the breating
>> space.
> The above still doesn't make much sense unless your range
> is disjoint 0-0.000000999, 1.0 which would be surprising and
> also doesn't correspond to the write.
>

I see the error - will fix. Will change in int + micro in the process.

>>
>> >> +             }
>> >> +             return IIO_VAL_INT_PLUS_NANO;
>> >> +
>> >> +     default:
>> >> +             return -EINVAL;
>> >> +     }
>> >> +}
>> >> +
>> >> +static int mlx90632_write_raw(struct iio_dev *indio_dev,
>> >> +                           struct iio_chan_spec const *channel, int val,
>> >> +                           int val2, long mask)
>> >> +{
>> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> >> +
>> >> +     switch (mask) {
>> >> +     case IIO_CHAN_INFO_CALIBEMISSIVITY:
>> >> +             if (val < 0 || val2 < 0 || val > 1 ||
>> >> +                 (val == 1 && val2 != 0))
>> >
>> > I'd add a comment describing what this is doing.  I think it
>> > is checking for 0-1.0 inclusive?
>> >
>>
>> Yes, exactly. In case you set emissivity outside of range it should
>> not change it and return EINVAL.
>>
>> >> +                     return -EINVAL;
>> >> +             data->emissivity = val * 1000 + val2 / 1000;
>> >> +             return 0;
>> >> +     default:
>> >> +             return -EINVAL;
>> >> +     }
>> >> +}
>> >> +
>> >> +static const struct iio_chan_spec mlx90632_channels[] = {
>> >> +     {
>> >> +             .type = IIO_TEMP,
>> >> +             .modified = 1,
>> >> +             .channel2 = IIO_MOD_TEMP_AMBIENT,
>> >> +             .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
>> >> +     },
>> >> +     {
>> >> +             .type = IIO_TEMP,
>> >> +             .modified = 1,
>> >> +             .channel2 = IIO_MOD_TEMP_OBJECT,
>> >> +             .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
>> >> +                     BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
>> >> +     },
>> >> +};
>> >> +
>> >> +static const struct iio_info mlx90632_info = {
>> >> +     .read_raw = mlx90632_read_raw,
>> >> +     .write_raw = mlx90632_write_raw,
>> >> +};
>> >> +
>> >> +#ifdef CONFIG_PM
>> >> +static int mlx90632_sleep(struct mlx90632_data *data)
>> >> +{
>> >> +     dev_dbg(&data->client->dev, "Requesting sleep");
>> >> +     return mlx90632_pwr_set_sleep_step(data->regmap);
>> >> +}
>> >> +
>> >> +static int mlx90632_wakeup(struct mlx90632_data *data)
>> >> +{
>> >> +     dev_dbg(&data->client->dev, "Requesting wake-up");
>> >> +     return mlx90632_pwr_continuous(data->regmap);
>> >> +}
>> >> +#endif
>> >> +
>> >> +static int mlx90632_probe(struct i2c_client *client,
>> >> +                       const struct i2c_device_id *id)
>> >> +{
>> >> +     struct iio_dev *indio_dev;
>> >> +     struct mlx90632_data *mlx90632;
>> >> +     struct regmap *regmap;
>> >> +     int ret;
>> >> +     unsigned int read;
>> >> +
>> >> +     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*mlx90632));
>> >> +     if (!indio_dev) {
>> >> +             dev_err(&client->dev, "Failed to allocate device");
>> >> +             return -ENOMEM;
>> >> +     }
>> >> +
>> >> +     regmap = devm_regmap_init_i2c(client, &mlx90632_regmap);
>> >> +     if (IS_ERR(regmap)) {
>> >> +             ret = PTR_ERR(regmap);
>> >> +             dev_err(&client->dev, "Failed to allocate regmap: %d\n", ret);
>> >> +             return ret;
>> >> +     }
>> >> +
>> >> +     mlx90632 = iio_priv(indio_dev);
>> >> +     i2c_set_clientdata(client, indio_dev);
>> >> +     mlx90632->client = client;
>> >> +     mlx90632->regmap = regmap;
>> >> +
>> >> +     mutex_init(&mlx90632->lock);
>> >> +     mlx90632_wakeup(mlx90632);
>> >> +
>> >> +     indio_dev->dev.parent = &client->dev;
>> >> +     indio_dev->name = id->name;
>> >> +     indio_dev->modes = INDIO_DIRECT_MODE;
>> >> +     indio_dev->info = &mlx90632_info;
>> >> +     indio_dev->channels = mlx90632_channels;
>> >> +     indio_dev->num_channels = ARRAY_SIZE(mlx90632_channels);
>> >> +
>> >> +     ret = regmap_read(mlx90632->regmap, MLX90632_EE_VERSION, &read);
>> >> +     if (ret < 0) {
>> >> +             dev_err(&client->dev, "read of version failed: %d\n", ret);
>> >> +             return ret;
>> >> +     }
>> >> +     if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_MEDICAL)) {
>> >
>> > This is odd.  Why the bitwise and of what look to be two different things entirely?
>> >
>>
>> If you look at how they are set (high vs low bits) you will see they
>> are complimentary and
>> prepared exactly for bitwise check. ID_MEDICAL might not be best name, but
>> EEPROM_ID_MEDICAL was just too long. You read 16 bits and that is why
>> lower 8 bits
>> are in fact EEPROM_VERSION while higher 8 are ID of calibration. Since
>> calculations
>> are currently dependent on lower 8 bits, I left some of the wiggle
>> space for future.
>> In case we add another one in future, but I would rather have a strict
>> check for this to
>> avoid any kind of confusion what is supported.
>
> Surely should be | then?
>
> read == (0xff05 & 0x01ff)
>
> read == (0x105)
> So only 3 bits of overlap?
>
> Definitely needs a comment to explain this int the code.
>

Nothing overlaps - thats the point. Just lower 8 bits are
EEPROM_VERSION and the higher are ID.
Will add a comment.

>>
>> >> +             dev_dbg(&client->dev,
>> >> +                     "Detected Medical EEPROM calibration %x", read);
>> >> +     } else if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_CONSUMER)) {
>> >> +             dev_dbg(&client->dev,
>> >> +                     "Detected Consumer EEPROM calibration %x", read);
>> >> +     } else {
>> >> +             dev_err(&client->dev,
>> >> +                     "Chip EEPROM version mismatch %x (expected %x)",
>> >> +                     read, MLX90632_EEPROM_VERSION);
>> >> +             return -EPROTONOSUPPORT;
>> >> +     }
>> >> +
>> >> +     mlx90632->emissivity = 1000;
>> >> +
>> >> +     return devm_iio_device_register(&client->dev, indio_dev);
>> >
>> > Don't use devm version.  You are (correctly) manually unwinding
>> > this in the remove (as you have pm to deal with after removing the
>> > interfaces).  This will result in a double free I think...
>> > return iio_device_register is the way to go.
>> >
>> > I'm a bit confused that you don't seem to set up runtime pm anywhere...
>> > I would assume we would be looking at autosuspend for a device
>> > like this but it isn't enabled..
>> >
>>
>> OK, will check how to use iio_device_register instead.
>>
>> I did not do much of PM on device, so I can't really say. That is
>> why autosuspend is not enabled.
>
> If you are dropping the PM for now, then devm_iio_device_register is
> fine, just drop the remove function entirely as it won't need to do
> anything.

In v3 I kept it as it seemed like simple fix, but if it is not really, then
I will remove it.

>>
>> >> +}
>> >> +
>> >> +static int mlx90632_remove(struct i2c_client *client)
>> >> +{
>> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> >> +
>> >> +     iio_device_unregister(indio_dev);
>> >> +
>> >> +     pm_runtime_disable(&client->dev);
>> >> +     if (!pm_runtime_status_suspended(&client->dev))
>> >> +             mlx90632_sleep(data);
>> >> +     pm_runtime_set_suspended(&client->dev);
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static const struct i2c_device_id mlx90632_id[] = {
>> >> +     { "mlx90632", 0 },
>> >> +     { }
>> >> +};
>> >> +MODULE_DEVICE_TABLE(i2c, mlx90632_id);
>> >> +
>> >> +static const struct of_device_id mlx90632_of_match[] = {
>> >> +     { .compatible = "melexis,mlx90632" },
>> >> +     { }
>> >> +};
>> >> +MODULE_DEVICE_TABLE(of, mlx90632_of_match);
>> >> +
>> >> +#ifdef CONFIG_PM_SLEEP
>> >> +static int mlx90632_pm_suspend(struct device *dev)
>> >> +{
>> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> >> +
>> >> +     if (pm_runtime_active(dev))
>> >> +             return mlx90632_sleep(data);
>> >
>> > I'm a little confused as to why, if the device is powered
>> > up fully and a suspend comes in we have to do less than we do
>> > in runtime pm case.
>> >
>> > Am I missing something?
>> >
>>
>> I think I have mostly tested runtime pm case, so this might have
>> been missed. I did get wrong results if I did not mark regcache as dirty.
>>
>> I will just remove the whole PM thing to start with and add it up later, OK?
>
> Makes sense.
>
>>
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int mlx90632_pm_resume(struct device *dev)
>> >> +{
>> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> >> +     struct mlx90632_data *data = iio_priv(indio_dev);
>> >> +     int err;
>> >> +
>> >> +     err = mlx90632_wakeup(data);
>> >> +     if (err < 0)
>> >> +             return err;
>> >> +
>> >> +     pm_runtime_disable(dev);
>> >> +     pm_runtime_set_active(dev);
>> >> +     pm_runtime_enable(dev);
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +#endif
>> >> +
>> >> +#ifdef CONFIG_PM
>> >> +static int mlx90632_pm_runtime_suspend(struct device *dev)
>> >> +{
>> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> >> +     struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
>> >> +
>> >> +     regcache_sync(mlx90632->regmap);
>> >> +
>> >> +     return mlx90632_sleep(mlx90632);
>> >> +}
>> >> +
>> >> +static int mlx90632_pm_runtime_resume(struct device *dev)
>> >> +{
>> >> +     s32 ret;
>> >> +     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>> >> +     struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
>> >> +
>> >> +     regcache_mark_dirty(mlx90632->regmap);
>> >> +     regcache_cache_only(mlx90632->regmap, false);
>> >> +     ret = regcache_sync(mlx90632->regmap);
>> >> +     if (ret < 0) {
>> >> +             dev_err(dev, "Failed to sync regmap registers: %d\n", ret);
>> >> +             return ret;
>> >> +     }
>> >> +
>> >> +     return mlx90632_wakeup(mlx90632);
>> >> +}
>> >> +#endif
>> >> +
>> >> +static const struct dev_pm_ops mlx90632_pm_ops = {
>> >> +     SET_SYSTEM_SLEEP_PM_OPS(mlx90632_pm_suspend, mlx90632_pm_resume)
>> >> +     SET_RUNTIME_PM_OPS(mlx90632_pm_runtime_suspend,
>> >> +                        mlx90632_pm_runtime_resume, NULL)
>> >> +};
>> >> +
>> >> +static struct i2c_driver mlx90632_driver = {
>> >> +     .driver = {
>> >> +             .name   = "mlx90632",
>> >> +             .of_match_table = mlx90632_of_match,
>> >> +             .pm     = &mlx90632_pm_ops,
>> >> +     },
>> >> +     .probe = mlx90632_probe,
>> >> +     .remove = mlx90632_remove,
>> >> +     .id_table = mlx90632_id,
>> >> +};
>> >> +module_i2c_driver(mlx90632_driver);
>> >> +
>> >> +MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
>> >> +MODULE_DESCRIPTION("Melexis MLX90632 contactless Infra Red temperature sensor driver");
>> >> +MODULE_LICENSE("GPL v2");
>> >
>> > --
>> > To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>> > the body of a message to majordomo@vger.kernel.org
>> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
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diff mbox

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 2d3d750b19c0..81aec02b08b8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8690,6 +8690,13 @@  W:	http://www.melexis.com
 S:	Supported
 F:	drivers/iio/temperature/mlx90614.c
 
+MELEXIS MLX90632 DRIVER
+M:	Crt Mori <cmo@melexis.com>
+L:	linux-iio@vger.kernel.org
+W:	http://www.melexis.com
+S:	Supported
+F:	drivers/iio/temperature/mlx90632.c
+
 MELFAS MIP4 TOUCHSCREEN DRIVER
 M:	Sangwon Jee <jeesw@melfas.com>
 W:	http://www.melfas.com
diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index 5378976d6d27..82e4a62745e2 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -43,6 +43,18 @@  config MLX90614
 	  This driver can also be built as a module. If so, the module will
 	  be called mlx90614.
 
+config MLX90632
+	tristate "MLX90632 contact-less infrared sensor with medical accuracy"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the Melexis
+	  MLX90632 contact-less infrared sensor with medical accuracy
+	  connected with I2C.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called mlx90632.
+
 config TMP006
 	tristate "TMP006 infrared thermopile sensor"
 	depends on I2C
diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
index ad1d668de546..44644fe01bc9 100644
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -5,6 +5,7 @@ 
 obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
 obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
 obj-$(CONFIG_MLX90614) += mlx90614.o
+obj-$(CONFIG_MLX90632) += mlx90632.o
 obj-$(CONFIG_TMP006) += tmp006.o
 obj-$(CONFIG_TMP007) += tmp007.o
 obj-$(CONFIG_TSYS01) += tsys01.o
diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
new file mode 100644
index 000000000000..05c7d943e504
--- /dev/null
+++ b/drivers/iio/temperature/mlx90632.c
@@ -0,0 +1,802 @@ 
+/*
+ * mlx90632.c - Melexis MLX90632 contactless IR temperature sensor
+ *
+ * Copyright (c) 2017 Melexis <cmo@melexis.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Driver for the Melexis MLX90632 I2C 16-bit IR thermopile sensor
+ */
+#include <asm/byteorder.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/math64.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/unaligned/be_byteshift.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+/* Memory sections addresses */
+#define MLX90632_ADDR_RAM	0x4000 /* Start address of ram */
+#define MLX90632_ADDR_EEPROM	0x2480 /* Start address of user eeprom */
+
+/* EEPROM addresses - used at startup */
+#define MLX90632_EE_CTRL	0x24d4 /* Control register initial value */
+#define MLX90632_EE_I2C_ADDR	0x24d5 /* I2C address register initial value */
+#define MLX90632_EE_VERSION	0x240b /* EEPROM version reg address */
+#define MLX90632_EE_P_R		0x240c /* P_R calibration register 32bit */
+#define MLX90632_EE_P_G		0x240e /* P_G calibration register 32bit */
+#define MLX90632_EE_P_T		0x2410 /* P_T calibration register 32bit */
+#define MLX90632_EE_P_O		0x2412 /* P_O calibration register 32bit */
+#define MLX90632_EE_Aa		0x2414 /* Aa calibration register 32bit */
+#define MLX90632_EE_Ab		0x2416 /* Ab calibration register 32bit */
+#define MLX90632_EE_Ba		0x2418 /* Ba calibration register 32bit */
+#define MLX90632_EE_Bb		0x241a /* Bb calibration register 32bit */
+#define MLX90632_EE_Ca		0x241c /* Ca calibration register 32bit */
+#define MLX90632_EE_Cb		0x241e /* Cb calibration register 32bit */
+#define MLX90632_EE_Da		0x2420 /* Da calibration register 32bit */
+#define MLX90632_EE_Db		0x2422 /* Db calibration register 32bit */
+#define MLX90632_EE_Ea		0x2424 /* Ea calibration register 32bit */
+#define MLX90632_EE_Eb		0x2426 /* Eb calibration register 32bit */
+#define MLX90632_EE_Fa		0x2428 /* Fa calibration register 32bit */
+#define MLX90632_EE_Fb		0x242a /* Fb calibration register 32bit */
+#define MLX90632_EE_Ga		0x242c /* Ga calibration register 32bit */
+
+#define MLX90632_EE_Gb		0x242e /* Gb calibration register 16bit */
+#define MLX90632_EE_Ka		0x242f /* Ka calibration register 16bit */
+
+#define MLX90632_EE_Ha		0x2481 /* Ha customer calib value reg 16bit */
+#define MLX90632_EE_Hb		0x2482 /* Hb customer calib value reg 16bit */
+
+/* Register addresses - volatile */
+#define MLX90632_REG_I2C_ADDR	0x3000 /* Chip I2C address register */
+
+/* Control register address - volatile */
+#define MLX90632_REG_CONTROL	0x3001 /* Control Register address */
+#define   MLX90632_CFG_PWR_MASK		GENMASK(2, 1) /* PowerMode Mask */
+/* PowerModes statuses */
+#define MLX90632_PWR_STATUS(ctrl_val) (ctrl_val << 1)
+#define MLX90632_PWR_STATUS_HALT MLX90632_PWR_STATUS(0) /* hold */
+#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step*/
+#define MLX90632_PWR_STATUS_STEP MLX90632_PWR_STATUS(2) /* step */
+#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous*/
+
+/* Device status register - volatile */
+#define MLX90632_REG_STATUS	0x3fff /* Device status register */
+#define   MLX90632_STAT_BUSY		BIT(10) /* Device busy indicator */
+#define   MLX90632_STAT_EE_BUSY		BIT(9) /* EEPROM busy indicator */
+#define   MLX90632_STAT_BRST		BIT(8) /* Brown out reset indicator */
+#define   MLX90632_STAT_CYCLE_POS	GENMASK(6, 2) /* Data position */
+#define   MLX90632_STAT_DATA_RDY	BIT(0) /* Data ready indicator */
+
+/* RAM_MEAS address-es for each channel */
+#define MLX90632_RAM_1(meas_num)	(MLX90632_ADDR_RAM + 3 * meas_num)
+#define MLX90632_RAM_2(meas_num)	(MLX90632_ADDR_RAM + 3 * meas_num + 1)
+#define MLX90632_RAM_3(meas_num)	(MLX90632_ADDR_RAM + 3 * meas_num + 2)
+
+/* Magic constants */
+#define MLX90632_EEPROM_VERSION	0xff05 /* EEPROM DSP version for constants */
+#define MLX90632_ID_MEDICAL	0x01ff /* EEPROM Medical device id */
+#define MLX90632_ID_CONSUMER	0x02ff /* EEPROM Consumer device id */
+#define MLX90632_EEPROM_WRITE_KEY 0x554C /* EEPROM write key 0x55 and 0x4c */
+#define MLX90632_RESET_CMD	0x0006 /* Reset sensor (address or global) */
+#define MLX90632_REF_12		12LL /**< ResCtrlRef value of Ch 1 or Ch 2 */
+#define MLX90632_REF_3		12LL /**< ResCtrlRef value of Channel 3 */
+
+#define TENTO3			1000LL
+#define TENTO4			10000LL
+#define TENTO5			100000LL
+#define TENTO6			1000000LL
+#define TENTO7			10000000LL
+#define TENTO10			10000000000LL
+#define TENTO12			1000000000000LL
+
+struct mlx90632_data {
+	struct i2c_client *client;
+	struct mutex lock; /* Multiple reads for single measurement */
+	struct regmap *regmap;
+	u16 emissivity;
+};
+
+static const struct regmap_range mlx90632_volatile_reg_range[] = {
+	regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
+	regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
+	regmap_reg_range(MLX90632_RAM_1(0),
+			 MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
+};
+
+static const struct regmap_access_table mlx90632_volatile_regs_tbl = {
+	.yes_ranges = mlx90632_volatile_reg_range,
+	.n_yes_ranges = ARRAY_SIZE(mlx90632_volatile_reg_range),
+};
+
+static const struct regmap_range mlx90632_read_reg_range[] = {
+	regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
+	regmap_reg_range(MLX90632_EE_CTRL, MLX90632_EE_I2C_ADDR),
+	regmap_reg_range(MLX90632_EE_Ha, MLX90632_EE_Hb),
+	regmap_reg_range(MLX90632_REG_CONTROL, MLX90632_REG_I2C_ADDR),
+	regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
+	regmap_reg_range(MLX90632_RAM_1(0),
+			 MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
+};
+
+static const struct regmap_access_table mlx90632_readable_regs_tbl = {
+	.yes_ranges = mlx90632_read_reg_range,
+	.n_yes_ranges = ARRAY_SIZE(mlx90632_read_reg_range),
+};
+
+static const struct regmap_range mlx90632_no_write_reg_range[] = {
+	regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
+	regmap_reg_range(MLX90632_RAM_1(0),
+			 MLX90632_RAM_3(MLX90632_MAX_MEAS_NUM)),
+};
+
+static const struct regmap_access_table mlx90632_writeable_regs_tbl = {
+	.no_ranges = mlx90632_no_write_reg_range,
+	.n_no_ranges = ARRAY_SIZE(mlx90632_no_write_reg_range),
+};
+
+static const struct regmap_config mlx90632_regmap = {
+	.reg_bits = 16,
+	.val_bits = 16,
+
+	.volatile_table = &mlx90632_volatile_regs_tbl,
+	.rd_table = &mlx90632_readable_regs_tbl,
+	.wr_table = &mlx90632_writeable_regs_tbl,
+
+	.use_single_rw = true,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static u64 mlx90632_int_sqrt(u64 x)
+{
+	u64 b, m, y = 0;
+
+	if (BITS_PER_LONG != 32)
+		return int_sqrt(x);
+
+	if (x <= 1)
+		return x;
+
+	m = 1ULL << (64 - 2);
+	while (m != 0) {
+		b = y + m;
+		y >>= 1;
+
+		if (x >= b) {
+			x -= b;
+			y += m;
+		}
+		m >>= 2;
+	}
+	return y;
+}
+
+static s32 mlx90632_pwr_set_sleep_step(struct regmap *regmap)
+{
+	return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
+				  MLX90632_CFG_PWR_MASK,
+				  MLX90632_PWR_STATUS_SLEEP_STEP);
+}
+
+static s32 mlx90632_pwr_set_step(struct regmap *regmap)
+{
+	return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
+				  MLX90632_CFG_PWR_MASK,
+				  MLX90632_PWR_STATUS_STEP);
+}
+
+static s32 mlx90632_pwr_continuous(struct regmap *regmap)
+{
+	return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
+				  MLX90632_CFG_PWR_MASK,
+				  MLX90632_PWR_STATUS_CONTINUOUS);
+}
+
+static int mlx90632_start_measurement(struct mlx90632_data *data)
+{
+	int ret, tries = 100;
+	unsigned int reg_status;
+
+	ret = regmap_update_bits(data->regmap, MLX90632_REG_STATUS,
+				 MLX90632_STAT_DATA_RDY, 0);
+	if (ret < 0)
+		return ret;
+
+	while (tries-- > 0) {
+		ret = regmap_read(data->regmap, MLX90632_REG_STATUS,
+				  &reg_status);
+		if (ret < 0)
+			return ret;
+		if (reg_status & MLX90632_STAT_DATA_RDY)
+			break;
+		usleep_range(10000, 11000);
+	}
+
+	if (tries < 0) {
+		dev_err(&data->client->dev, "data not ready");
+		return -ETIMEDOUT;
+	}
+
+	return (reg_status & MLX90632_STAT_CYCLE_POS) >> 2;
+}
+
+static int mlx9032_channel_new_select(int ret, uint8_t *channel_new,
+				      uint8_t *channel_old)
+{
+	if (ret == 1) {
+		*channel_new = 1;
+		*channel_old = 2;
+	} else if (ret == 2) {
+		*channel_new = 2;
+		*channel_old = 1;
+	} else {
+		return ret;
+	}
+	return 0;
+}
+
+static int mlx90632_read_ambient_raw(struct regmap *regmap,
+				     s16 *ambient_new_raw, s16 *ambient_old_raw)
+{
+	int ret;
+	unsigned int read_tmp;
+
+	ret = regmap_read(regmap, MLX90632_RAM_3(1), &read_tmp);
+	if (ret < 0)
+		return ret;
+	*ambient_new_raw = (s16)read_tmp;
+
+	ret = regmap_read(regmap, MLX90632_RAM_3(2), &read_tmp);
+	if (ret < 0)
+		return ret;
+	*ambient_old_raw = (s16)read_tmp;
+
+	return ret;
+}
+
+static int mlx90632_read_object_raw(struct regmap *regmap,
+				    int start_measurement_ret,
+				    s16 *object_new_raw, s16 *object_old_raw)
+{
+	int ret;
+	unsigned int read_tmp;
+	s16 read;
+	u8 channel = 0;
+	u8 channel_old = 0;
+
+	ret = mlx90632_channel_new_select(start_measurement_ret, &channel,
+					  &channel_old);
+	if (ret != 0)
+		return ret;
+
+	ret = regmap_read(regmap, MLX90632_RAM_2(channel), &read_tmp);
+	if (ret < 0)
+		return ret;
+
+	read = (s16)read_tmp;
+
+	ret = regmap_read(regmap, MLX90632_RAM_1(channel), &read_tmp);
+	if (ret < 0)
+		return ret;
+	*object_new_raw = (read + (s16)read_tmp) / 2;
+
+	ret = regmap_read(regmap, MLX90632_RAM_2(channel_old), &read_tmp);
+	if (ret < 0)
+		return ret;
+	read = (s16)read_tmp;
+
+	ret = regmap_read(regmap, MLX90632_RAM_1(channel_old), &read_tmp);
+	if (ret < 0)
+		return ret;
+	*object_old_raw = (read + (s16)read_tmp) / 2;
+
+	return ret;
+}
+
+static int mlx90632_read_all_channel(struct mlx90632_data *data,
+				     s16 *ambient_new_raw, s16 *ambient_old_raw,
+				     s16 *object_new_raw, s16 *object_old_raw)
+{
+	s32 ret, tm_ret;
+
+	mutex_lock(&data->lock);
+	tm_ret = mlx90632_start_measurement(data);
+	if (tm_ret >= 0) {
+		ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
+						ambient_old_raw);
+		if (ret >= 0) {
+			ret = mlx90632_read_object_raw(data->regmap, tm_ret,
+						       object_new_raw,
+						       object_old_raw);
+		}
+	} else {
+		ret = tm_ret;
+	}
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static int mlx90632_read_ee_register(struct regmap *regmap, u16 reg_lsb,
+				     s32 *reg_value)
+{
+	s32 ret;
+	unsigned int read;
+	__le32 value;
+
+	ret = regmap_read(regmap, reg_lsb, &read);
+	if (ret < 0)
+		return ret;
+
+	value = cpu_to_le32(read);
+
+	ret = regmap_read(regmap, reg_lsb + 1, &read);
+	if (ret < 0)
+		return ret;
+
+	value = (cpu_to_le32(read) << 16) | (value & 0xffff);
+
+	*reg_value = le32_to_cpu(value);
+	return 0;
+}
+
+static s64 mlx90632_preprocess_temp_amb(s16 ambient_new_raw,
+					s16 ambient_old_raw, s16 Gb)
+{
+	s64 VR_Ta, kGb, tmp;
+
+	kGb = ((s64)Gb * TENTO3) >> 10ULL;
+	VR_Ta = (s64)ambient_old_raw * TENTO6 +
+		kGb * div64_s64(((s64)ambient_new_raw * TENTO3),
+			(MLX90632_REF_3));
+	tmp = div64_s64(
+			 div64_s64(((s64)ambient_new_raw * TENTO12),
+				   (MLX90632_REF_3)), VR_Ta);
+	return div64_s64(tmp << 19ULL, TENTO3);
+}
+
+static s64 mlx90632_preprocess_temp_obj(s16 object_new_raw, s16 object_old_raw,
+					s16 ambient_new_raw,
+					s16 ambient_old_raw, s16 Ka)
+{
+	s64 VR_IR, kKa, tmp;
+
+	kKa = ((s64)Ka * TENTO3) >> 10ULL;
+	VR_IR = (s64)ambient_old_raw * TENTO6 +
+		kKa * div64_s64(((s64)ambient_new_raw * TENTO3),
+			(MLX90632_REF_3));
+	tmp = div64_s64(
+			div64_s64(((s64)((object_new_raw + object_old_raw) / 2)
+				   * TENTO12), (MLX90632_REF_12)), VR_IR);
+	return div64_s64(tmp << 19ULL), TENTO3);
+}
+
+static s32 mlx90632_calc_temp_ambient(s16 ambient_new_raw, s16 ambient_old_raw,
+				      s32 P_T, s32 P_R, s32 P_G, s32 P_O,
+				      s16 Gb)
+{
+	s64 Asub, Bsub, Ablock, Bblock, Cblock, AMB, sum;
+
+	AMB = mlx90632_preprocess_temp_amb(ambient_new_raw, ambient_old_raw,
+					   Gb);
+	Asub = ((s64)P_T * TENTO10) >> 44ULL;
+	Bsub = AMB - (((s64)P_R * TENTO3) >> 8ULL);
+	Ablock = Asub * (Bsub * Bsub);
+	Bblock = (div64_s64(Bsub * TENTO7, P_G)) << 20ULL;
+	Cblock = ((s64)P_O * TENTO10) >> 8ULL;
+
+	sum = div64_s64(Ablock, TENTO6) + Bblock + Cblock;
+
+	return div64_s64(sum, TENTO7);
+}
+
+static s32 mlx90632_calc_temp_object_iteration(s32 prev_object_temp, s64 object,
+					       s64 TAdut, s32 Fa, s32 Fb,
+					       s32 Ga, s16 Ha, s16 Hb,
+					       u16 emissivity)
+{
+	s64 calcedKsTO, calcedKsTA, ir_Alpha, TAdut4, Alpha_corr;
+	s64 Ha_customer, Hb_customer;
+
+	Ha_customer = ((s64)Ha * TENTO6) >> 14ULL;
+	Hb_customer = ((s64)Hb * 100) >> 10ULL;
+
+	calcedKsTO = ((s64)((s64)Ga * (prev_object_temp - 25 * TENTO3)
+			     * TENTO3)) >> 36LL;
+	calcedKsTA = ((s64)(Fb * (TAdut - 25 * TENTO6))) >> 36LL;
+	Alpha_corr = div64_s64((((s64)(Fa * TENTO10) >> 46LL) * Ha_customer),
+			       TENTO3);
+	Alpha_corr *= ((s64)(1 * TENTO6 + calcedKsTO + calcedKsTA));
+	Alpha_corr = emissivity * div64_s64(Alpha_corr, TENTO5);
+	Alpha_corr = div64_s64(Alpha_corr, TENTO3);
+	ir_Alpha = div64_s64((s64)object * TENTO7, Alpha_corr);
+	TAdut4 = (div64_s64(TAdut, TENTO4) + 27315) *
+		(div64_s64(TAdut, TENTO4) + 27315) *
+		(div64_s64(TAdut, TENTO4)  + 27315) *
+		(div64_s64(TAdut, TENTO4) + 27315);
+
+	return (mlx90632_int_sqrt(
+			 mlx90632_int_sqrt(ir_Alpha * TENTO12 + TAdut4)
+			) - 27315 - Hb_customer) * 10;
+}
+
+static s32 mlx90632_calc_temp_object(s64 object, s64 ambient, s32 Ea, s32 Eb,
+				     s32 Fa, s32 Fb, s32 Ga, s16 Ha, s16 Hb,
+				     u16 tmp_emi)
+{
+	s64 kTA, kTA0, TAdut;
+	s64 temp = 25000;
+	s8 i;
+
+	kTA = (Ea * TENTO3) >> 16LL;
+	kTA0 = (Eb * TENTO3) >> 8LL;
+	TAdut = div64_s64(((ambient - kTA0) * TENTO6), kTA) + 25 * TENTO6;
+
+	for (i = 0; i < 5; ++i) {
+		temp = mlx90632_calc_temp_object_iteration(temp, object, TAdut,
+							   Fa, Fb, Ga, Ha, Hb,
+							   tmp_emi);
+	}
+	return temp;
+}
+
+static int mlx90632_calc_object_dsp105(struct mlx90632_data *data, int *val)
+{
+	s32 ret;
+	s32 Ea, Eb, Fa, Fb, Ga;
+	unsigned int read_tmp;
+	s16 Ha, Hb, Gb, Ka;
+	s16 ambient_new_raw, ambient_old_raw, object_new_raw, object_old_raw;
+	s64 object, ambient;
+
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ea, &Ea);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Eb, &Eb);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fa, &Fa);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Fb, &Fb);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_Ga, &Ga);
+	if (ret < 0)
+		return ret;
+	ret = regmap_read(data->regmap, MLX90632_EE_Ha, &read_tmp);
+	if (ret < 0)
+		return ret;
+	Ha = (s16)read_tmp;
+	ret = regmap_read(data->regmap, MLX90632_EE_Hb, &read_tmp);
+	if (ret < 0)
+		return ret;
+	Hb = (s16)read_tmp;
+	ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
+	if (ret < 0)
+		return ret;
+	Gb = (s16)read_tmp;
+	ret = regmap_read(data->regmap, MLX90632_EE_Ka, &read_tmp);
+	if (ret < 0)
+		return ret;
+	Ka = (s16)read_tmp;
+
+	ret = mlx90632_read_all_channel(data,
+					&ambient_new_raw, &ambient_old_raw,
+					&object_new_raw, &object_old_raw);
+	if (ret < 0)
+		return ret;
+
+	ambient = mlx90632_preprocess_temp_amb(ambient_new_raw,
+					       ambient_old_raw, Gb);
+	object = mlx90632_preprocess_temp_obj(object_new_raw,
+					      object_old_raw,
+					      ambient_new_raw,
+					      ambient_old_raw, Ka);
+
+	*val = mlx90632_calc_temp_object(object, ambient, Ea, Eb, Fa, Fb, Ga,
+					 Ha, Hb, data->emissivity);
+	return 0;
+}
+
+static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
+{
+	s32 ret;
+	unsigned int read_tmp;
+	s32 PT, PR, PG, PO;
+	s16 Gb;
+	s16 ambient_new_raw, ambient_old_raw;
+
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_R, &PR);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_G, &PG);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_T, &PT);
+	if (ret < 0)
+		return ret;
+	ret = mlx90632_read_ee_register(data->regmap, MLX90632_EE_P_O, &PO);
+	if (ret < 0)
+		return ret;
+	ret = regmap_read(data->regmap, MLX90632_EE_Gb, &read_tmp);
+	if (ret < 0)
+		return ret;
+	Gb = (s16)read_tmp;
+
+	ret = mlx90632_read_ambient_raw(data->regmap, &ambient_new_raw,
+					&ambient_old_raw);
+	*val = mlx90632_calc_temp_ambient(ambient_new_raw, ambient_old_raw,
+					  PT, PR, PG, PO, Gb);
+	return ret;
+}
+
+static int mlx90632_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *channel, int *val,
+			     int *val2, long mask)
+{
+	struct mlx90632_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (channel->channel2) {
+		case IIO_MOD_TEMP_AMBIENT:
+			ret = mlx90632_calc_ambient_dsp105(data, val);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT;
+		case IIO_MOD_TEMP_OBJECT:
+			ret = mlx90632_calc_object_dsp105(data, val);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_CALIBEMISSIVITY:
+		if (data->emissivity == 1000) {
+			*val = 1;
+			*val2 = 0;
+		} else {
+			*val = 0;
+			*val2 = data->emissivity;
+		}
+		return IIO_VAL_INT_PLUS_NANO;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int mlx90632_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *channel, int val,
+			      int val2, long mask)
+{
+	struct mlx90632_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_CALIBEMISSIVITY:
+		if (val < 0 || val2 < 0 || val > 1 ||
+		    (val == 1 && val2 != 0))
+			return -EINVAL;
+		data->emissivity = val * 1000 + val2 / 1000;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_chan_spec mlx90632_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.modified = 1,
+		.channel2 = IIO_MOD_TEMP_AMBIENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	{
+		.type = IIO_TEMP,
+		.modified = 1,
+		.channel2 = IIO_MOD_TEMP_OBJECT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+			BIT(IIO_CHAN_INFO_CALIBEMISSIVITY),
+	},
+};
+
+static const struct iio_info mlx90632_info = {
+	.read_raw = mlx90632_read_raw,
+	.write_raw = mlx90632_write_raw,
+};
+
+#ifdef CONFIG_PM
+static int mlx90632_sleep(struct mlx90632_data *data)
+{
+	dev_dbg(&data->client->dev, "Requesting sleep");
+	return mlx90632_pwr_set_sleep_step(data->regmap);
+}
+
+static int mlx90632_wakeup(struct mlx90632_data *data)
+{
+	dev_dbg(&data->client->dev, "Requesting wake-up");
+	return mlx90632_pwr_continuous(data->regmap);
+}
+#endif
+
+static int mlx90632_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct mlx90632_data *mlx90632;
+	struct regmap *regmap;
+	int ret;
+	unsigned int read;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*mlx90632));
+	if (!indio_dev) {
+		dev_err(&client->dev, "Failed to allocate device");
+		return -ENOMEM;
+	}
+
+	regmap = devm_regmap_init_i2c(client, &mlx90632_regmap);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(&client->dev, "Failed to allocate regmap: %d\n", ret);
+		return ret;
+	}
+
+	mlx90632 = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	mlx90632->client = client;
+	mlx90632->regmap = regmap;
+
+	mutex_init(&mlx90632->lock);
+	mlx90632_wakeup(mlx90632);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = id->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &mlx90632_info;
+	indio_dev->channels = mlx90632_channels;
+	indio_dev->num_channels = ARRAY_SIZE(mlx90632_channels);
+
+	ret = regmap_read(mlx90632->regmap, MLX90632_EE_VERSION, &read);
+	if (ret < 0) {
+		dev_err(&client->dev, "read of version failed: %d\n", ret);
+		return ret;
+	}
+	if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_MEDICAL)) {
+		dev_dbg(&client->dev,
+			"Detected Medical EEPROM calibration %x", read);
+	} else if (read == (MLX90632_EEPROM_VERSION & MLX90632_ID_CONSUMER)) {
+		dev_dbg(&client->dev,
+			"Detected Consumer EEPROM calibration %x", read);
+	} else {
+		dev_err(&client->dev,
+			"Chip EEPROM version mismatch %x (expected %x)",
+			read, MLX90632_EEPROM_VERSION);
+		return -EPROTONOSUPPORT;
+	}
+
+	mlx90632->emissivity = 1000;
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int mlx90632_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct mlx90632_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	pm_runtime_disable(&client->dev);
+	if (!pm_runtime_status_suspended(&client->dev))
+		mlx90632_sleep(data);
+	pm_runtime_set_suspended(&client->dev);
+
+	return 0;
+}
+
+static const struct i2c_device_id mlx90632_id[] = {
+	{ "mlx90632", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mlx90632_id);
+
+static const struct of_device_id mlx90632_of_match[] = {
+	{ .compatible = "melexis,mlx90632" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mlx90632_of_match);
+
+#ifdef CONFIG_PM_SLEEP
+static int mlx90632_pm_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct mlx90632_data *data = iio_priv(indio_dev);
+
+	if (pm_runtime_active(dev))
+		return mlx90632_sleep(data);
+
+	return 0;
+}
+
+static int mlx90632_pm_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct mlx90632_data *data = iio_priv(indio_dev);
+	int err;
+
+	err = mlx90632_wakeup(data);
+	if (err < 0)
+		return err;
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int mlx90632_pm_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
+
+	regcache_sync(mlx90632->regmap);
+
+	return mlx90632_sleep(mlx90632);
+}
+
+static int mlx90632_pm_runtime_resume(struct device *dev)
+{
+	s32 ret;
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct mlx90632_data *mlx90632 = iio_priv(indio_dev);
+
+	regcache_mark_dirty(mlx90632->regmap);
+	regcache_cache_only(mlx90632->regmap, false);
+	ret = regcache_sync(mlx90632->regmap);
+	if (ret < 0) {
+		dev_err(dev, "Failed to sync regmap registers: %d\n", ret);
+		return ret;
+	}
+
+	return mlx90632_wakeup(mlx90632);
+}
+#endif
+
+static const struct dev_pm_ops mlx90632_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(mlx90632_pm_suspend, mlx90632_pm_resume)
+	SET_RUNTIME_PM_OPS(mlx90632_pm_runtime_suspend,
+			   mlx90632_pm_runtime_resume, NULL)
+};
+
+static struct i2c_driver mlx90632_driver = {
+	.driver = {
+		.name	= "mlx90632",
+		.of_match_table = mlx90632_of_match,
+		.pm	= &mlx90632_pm_ops,
+	},
+	.probe = mlx90632_probe,
+	.remove = mlx90632_remove,
+	.id_table = mlx90632_id,
+};
+module_i2c_driver(mlx90632_driver);
+
+MODULE_AUTHOR("Crt Mori <cmo@melexis.com>");
+MODULE_DESCRIPTION("Melexis MLX90632 contactless Infra Red temperature sensor driver");
+MODULE_LICENSE("GPL v2");