| Message ID | 20220704053901.728-14-peterwu.pub@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add Mediatek MT6370 PMIC support | expand |
On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > From: ChiaEn Wu <chiaen_wu@richtek.com> > > Add Mediatek MT6370 Backlight support. ... > + This driver can also be built as a module. If so the module If so, > + will be called "mt6370-backlight.ko". No ".ko" part. ... > +#include <linux/gpio/driver.h> Can you elaborate on this? > +#include <linux/kernel.h> > +#include <linux/log2.h> > +#include <linux/minmax.h> > +#include <linux/module.h> > +#include <linux/of.h> Can you elaborate on this? > +#include <linux/platform_device.h> > +#include <linux/regmap.h> Missed mod_devicetable.h. ... > + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; > + brightness_val[1] = (brightness - 1) > + >> fls(MT6370_BL_DIM2_MASK); Bad indentation. One line? ... > + if (priv->enable_gpio) Dup check. > + gpiod_set_value(priv->enable_gpio, brightness ? 1 : 0); ... > + brightness = brightness_val[1] << fls(MT6370_BL_DIM2_MASK); > + brightness += (brightness_val[0] & MT6370_BL_DIM2_MASK); Too many parentheses. ... > + /* > + * prop_val = 1 --> 1 steps --> 0x00 > + * prop_val = 2 ~ 4 --> 4 steps --> 0x01 > + * prop_val = 5 ~ 16 --> 16 steps --> 0x10 > + * prop_val = 17 ~ 64 --> 64 steps --> 0x11 > + */ > + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1; Isn't something closer to get_order() or fls()? ... > + props->max_brightness = min_t(u32, brightness, > + MT6370_BL_MAX_BRIGHTNESS); One line? ... > + val = 0; Do you need this here? > + prop_val = 0; Useless. > + ret = device_property_read_u8(dev, "mediatek,bled-channel-use", > + &prop_val); > + if (ret) { > + dev_err(dev, "mediatek,bled-channel-use DT property missing\n"); > + return ret; > + } > + > + if (!prop_val || prop_val > MT6370_BL_MAX_CH) { > + dev_err(dev, > + "No channel specified or over than upper bound (%d)\n", > + prop_val); > + return -EINVAL; > + } ... > +static int mt6370_bl_probe(struct platform_device *pdev) > +{ > + struct mt6370_priv *priv; > + struct backlight_properties props = { > + .type = BACKLIGHT_RAW, > + .scale = BACKLIGHT_SCALE_LINEAR, > + }; > + int ret; struct device *dev = &pdev->dev; will save you a few LoCs.
Hi Andy, Thanks for your reply! I have some questions want to ask you below. Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月5日 週二 清晨5:14寫道： > > On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > > > From: ChiaEn Wu <chiaen_wu@richtek.com> > > > > Add Mediatek MT6370 Backlight support. > > ... > > > + This driver can also be built as a module. If so the module > > If so, > > > + will be called "mt6370-backlight.ko". > > No ".ko" part. > > ... > > > +#include <linux/gpio/driver.h> > > Can you elaborate on this? > > > +#include <linux/kernel.h> > > +#include <linux/log2.h> > > +#include <linux/minmax.h> > > +#include <linux/module.h> > > > +#include <linux/of.h> > > Can you elaborate on this? > > > +#include <linux/platform_device.h> > > +#include <linux/regmap.h> > > Missed mod_devicetable.h. > > ... > > > + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; > > + brightness_val[1] = (brightness - 1) > > + >> fls(MT6370_BL_DIM2_MASK); > > Bad indentation. One line? Well... if indent to one line, it will be over 80 characters(or called columns?) From my understanding, it is not allowed, right?? > > ... > > > + if (priv->enable_gpio) > > Dup check. > > > + gpiod_set_value(priv->enable_gpio, brightness ? 1 : 0); > > ... > > > + brightness = brightness_val[1] << fls(MT6370_BL_DIM2_MASK); > > + brightness += (brightness_val[0] & MT6370_BL_DIM2_MASK); > > Too many parentheses. > > ... > > > + /* > > + * prop_val = 1 --> 1 steps --> 0x00 > > + * prop_val = 2 ~ 4 --> 4 steps --> 0x01 > > + * prop_val = 5 ~ 16 --> 16 steps --> 0x10 > > + * prop_val = 17 ~ 64 --> 64 steps --> 0x11 > > + */ > > + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1; > > Isn't something closer to get_order() or fls()? I will revise it to "(get_order(prop_va * PAGE_SIZE) + 1) / 2" and this change is meet your expectations?? > > ... > > > + props->max_brightness = min_t(u32, brightness, > > + MT6370_BL_MAX_BRIGHTNESS); > > One line? Ditto, it will be over 80 characters... > > ... > > > + val = 0; > > Do you need this here? > > > + prop_val = 0; > > Useless. > > > + ret = device_property_read_u8(dev, "mediatek,bled-channel-use", > > + &prop_val); > > + if (ret) { > > + dev_err(dev, "mediatek,bled-channel-use DT property missing\n"); > > + return ret; > > + } > > + > > + if (!prop_val || prop_val > MT6370_BL_MAX_CH) { > > + dev_err(dev, > > + "No channel specified or over than upper bound (%d)\n", > > + prop_val); > > + return -EINVAL; > > + } > > ... > > > +static int mt6370_bl_probe(struct platform_device *pdev) > > +{ > > + struct mt6370_priv *priv; > > + struct backlight_properties props = { > > + .type = BACKLIGHT_RAW, > > + .scale = BACKLIGHT_SCALE_LINEAR, > > + }; > > + int ret; > > struct device *dev = &pdev->dev; > > will save you a few LoCs. > > -- > With Best Regards, > Andy Shevchenko Best regards, ChiaEn Wu
On Wed, Jul 13, 2022 at 12:53 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月5日 週二 清晨5:14寫道： > > On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: Please, remove unneeded context when replying! ... > > > + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; > > > + brightness_val[1] = (brightness - 1) > > > + >> fls(MT6370_BL_DIM2_MASK); > > > > Bad indentation. One line? > > Well... if indent to one line, it will be over 80 characters(or called columns?) > From my understanding, it is not allowed, right?? It's allowed to some extent.Use your common sense. Here it's obviously broken indentation. ... > > > + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1; > > > > Isn't something closer to get_order() or fls()? > > I will revise it to "(get_order(prop_va * PAGE_SIZE) + 1) / 2" and > this change is meet your expectations?? Nope. Try again. What about fls()? ... > > > + props->max_brightness = min_t(u32, brightness, > > > + MT6370_BL_MAX_BRIGHTNESS); > > > > One line? > > Ditto, it will be over 80 characters... As per above.
On Wed, 13 Jul 2022, Andy Shevchenko wrote: > On Wed, Jul 13, 2022 at 12:53 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月5日 週二 清晨5:14寫道： > > > On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > Please, remove unneeded context when replying! > > ... > > > > > + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; > > > > + brightness_val[1] = (brightness - 1) > > > > + >> fls(MT6370_BL_DIM2_MASK); > > > > > > Bad indentation. One line? > > > > Well... if indent to one line, it will be over 80 characters(or called columns?) > > From my understanding, it is not allowed, right?? > > It's allowed to some extent.Use your common sense. > Here it's obviously broken indentation. Refrain from going crazy though - hard limit is 100 chars.
Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月13日 週三 晚上8:07寫道： > > On Wed, Jul 13, 2022 at 12:53 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月5日 週二 清晨5:14寫道： > > > On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > Please, remove unneeded context when replying! > > ... > > > > > + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; > > > > + brightness_val[1] = (brightness - 1) > > > > + >> fls(MT6370_BL_DIM2_MASK); > > > > > > Bad indentation. One line? > > > > Well... if indent to one line, it will be over 80 characters(or called columns?) > > From my understanding, it is not allowed, right?? > > It's allowed to some extent.Use your common sense. > Here it's obviously broken indentation. > > ... > > > > > + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1; > > > > > > Isn't something closer to get_order() or fls()? > > > > I will revise it to "(get_order(prop_va * PAGE_SIZE) + 1) / 2" and > > this change is meet your expectations?? > > Nope. Try again. What about fls()? I have tried two methods so far, as follows ------------------------------------------------------------- /* * prop_val = 1 --> 1 steps --> b'00 * prop_val = 2 ~ 4 --> 4 steps --> b'01 * prop_val = 5 ~ 16 --> 16 steps --> b'10 * prop_val = 17 ~ 64 --> 64 steps --> b'11 */ // 1. use fls() and ffs() combination prop_val = ffs(prop_val) == fls(prop_val) ? fls(prop_val) >> 1 : (fls(prop_val) + 1) >> 1; // 2. use one line for-loop, but without fls() for (i = --prop_val, prop_val = 0; i >> 2 * prop_val != 0; prop_val++); ------------------------------------------------------------- Do these changes meet your expectations?? > > ... > > > > > + props->max_brightness = min_t(u32, brightness, > > > > + MT6370_BL_MAX_BRIGHTNESS); > > > > > > One line? > > > > Ditto, it will be over 80 characters... > > As per above. > > -- > With Best Regards, > Andy Shevchenko
On Thu, Jul 14, 2022 at 9:13 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月13日 週三 晚上8:07寫道： > > On Wed, Jul 13, 2022 at 12:53 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月5日 週二 清晨5:14寫道： > > > > On Mon, Jul 4, 2022 at 7:43 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: Please, once again, remove unneeded context when replying! ^^^^^^^ ... > > > > > + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1; > > > > > > > > Isn't something closer to get_order() or fls()? > > > > > > I will revise it to "(get_order(prop_va * PAGE_SIZE) + 1) / 2" and > > > this change is meet your expectations?? > > > > Nope. Try again. What about fls()? > > I have tried two methods so far, as follows > ------------------------------------------------------------- > /* > * prop_val = 1 --> 1 steps --> b'00 > * prop_val = 2 ~ 4 --> 4 steps --> b'01 > * prop_val = 5 ~ 16 --> 16 steps --> b'10 > * prop_val = 17 ~ 64 --> 64 steps --> b'11 > */ So, for 1 --> 0, for 2 --> 1, for 5 --> 2, and for 17 --> 3. Now, consider x - 1: 0 ( 0 ) --> 0 1 (2^0) --> 1 4 (2^2) --> 2 16 (2^4) --> 3 64 (2^6) --> ? (but let's consider that the range has been checked already) Since we take the lower limit, it means ffs(): y = (ffs(x - 1) + 1) / 2; Does it work for you? > // 1. use fls() and ffs() combination > prop_val = ffs(prop_val) == fls(prop_val) ? fls(prop_val) >> 1 : > (fls(prop_val) + 1) >> 1; > > // 2. use one line for-loop, but without fls() > for (i = --prop_val, prop_val = 0; i >> 2 * prop_val != 0; prop_val++); > ------------------------------------------------------------- > Do these changes meet your expectations?? No, this is ugly. Yes, I understand that a bit arithmetics is hard...
On Thu, Jul 14, 2022 at 11:27 AM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > On Thu, Jul 14, 2022 at 9:13 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月13日 週三 晚上8:07寫道： ... > > I have tried two methods so far, as follows > > ------------------------------------------------------------- > > /* > > * prop_val = 1 --> 1 steps --> b'00 > > * prop_val = 2 ~ 4 --> 4 steps --> b'01 > > * prop_val = 5 ~ 16 --> 16 steps --> b'10 > > * prop_val = 17 ~ 64 --> 64 steps --> b'11 > > */ > > So, for 1 --> 0, for 2 --> 1, for 5 --> 2, and for 17 --> 3. > Now, consider x - 1: > 0 ( 0 ) --> 0 > 1 (2^0) --> 1 > 4 (2^2) --> 2 > 16 (2^4) --> 3 > 64 (2^6) --> ? (but let's consider that the range has been checked already) > > Since we take the lower limit, it means ffs(): > > y = (ffs(x - 1) + 1) / 2; > > Does it work for you? It wouldn't, because we need to use fls() against it actually. So, 0..1 (-1..0) --> 0 2..4 (1..3) --> 1 5..16 (4..15) --> 2 17..64 (16..63) --> 3 y = x ? ((fls(x - 1) + 1) / 2 : 0;
On Thu, Jul 14, 2022 at 11:27:07AM +0200, Andy Shevchenko wrote: > On Thu, Jul 14, 2022 at 9:13 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > I have tried two methods so far, as follows > > ------------------------------------------------------------- > > /* > > * prop_val = 1 --> 1 steps --> b'00 > > * prop_val = 2 ~ 4 --> 4 steps --> b'01 > > * prop_val = 5 ~ 16 --> 16 steps --> b'10 > > * prop_val = 17 ~ 64 --> 64 steps --> b'11 > > */ > > So, for 1 --> 0, for 2 --> 1, for 5 --> 2, and for 17 --> 3. > Now, consider x - 1: > 0 ( 0 ) --> 0 > 1 (2^0) --> 1 > 4 (2^2) --> 2 > 16 (2^4) --> 3 > 64 (2^6) --> ? (but let's consider that the range has been checked already) > > Since we take the lower limit, it means ffs(): > > y = (ffs(x - 1) + 1) / 2; > > Does it work for you? To be honest, for this tiny table, writing code that *doesn't* require intricate deciphering together with a huge comment saying what is does would probably be better: prop_val = (prop_val <= 1 ? 0 : prop_val <= 4 ? 1 : prop_val <= 16 ? 2 : 3); This would be "obviously correct" and require no comment. Daniel.
On Thu, Jul 14, 2022 at 11:47 AM Daniel Thompson <daniel.thompson@linaro.org> wrote: > > On Thu, Jul 14, 2022 at 11:27:07AM +0200, Andy Shevchenko wrote: > > On Thu, Jul 14, 2022 at 9:13 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > > I have tried two methods so far, as follows > > > ------------------------------------------------------------- > > > /* > > > * prop_val = 1 --> 1 steps --> b'00 > > > * prop_val = 2 ~ 4 --> 4 steps --> b'01 > > > * prop_val = 5 ~ 16 --> 16 steps --> b'10 > > > * prop_val = 17 ~ 64 --> 64 steps --> b'11 > > > */ > > > > So, for 1 --> 0, for 2 --> 1, for 5 --> 2, and for 17 --> 3. > > Now, consider x - 1: > > 0 ( 0 ) --> 0 > > 1 (2^0) --> 1 > > 4 (2^2) --> 2 > > 16 (2^4) --> 3 > > 64 (2^6) --> ? (but let's consider that the range has been checked already) > > > > Since we take the lower limit, it means ffs(): > > > > y = (ffs(x - 1) + 1) / 2; > > > > Does it work for you? > > To be honest, for this tiny table, writing code that *doesn't* require intricate > deciphering together with a huge comment saying what is does would probably be > better: > > prop_val = (prop_val <= 1 ? 0 : > prop_val <= 4 ? 1 : > prop_val <= 16 ? 2 : > 3); > > This would be "obviously correct" and require no comment. Agree. It will also limit checking (and whatever needed for that).
On Thu, Jul 14, 2022 at 11:43 AM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Thu, Jul 14, 2022 at 11:27 AM Andy Shevchenko > <andy.shevchenko@gmail.com> wrote: > > On Thu, Jul 14, 2022 at 9:13 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote: > > > Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月13日 週三 晚上8:07寫道： ... > > > * prop_val = 1 --> 1 steps --> b'00 > > > * prop_val = 2 ~ 4 --> 4 steps --> b'01 > > > * prop_val = 5 ~ 16 --> 16 steps --> b'10 > > > * prop_val = 17 ~ 64 --> 64 steps --> b'11 > > > > So, for 1 --> 0, for 2 --> 1, for 5 --> 2, and for 17 --> 3. > > Now, consider x - 1: > > 0 ( 0 ) --> 0 > > 1 (2^0) --> 1 > > 4 (2^2) --> 2 > > 16 (2^4) --> 3 > > 64 (2^6) --> ? (but let's consider that the range has been checked already) > > > > Since we take the lower limit, it means ffs(): > > > > y = (ffs(x - 1) + 1) / 2; > > > > Does it work for you? > > It wouldn't, because we need to use fls() against it actually. > > So, > 0..1 (-1..0) --> 0 > 2..4 (1..3) --> 1 > 5..16 (4..15) --> 2 > 17..64 (16..63) --> 3 > > y = x ? ((fls(x - 1) + 1) / 2 : 0; Okay, I nailed it down, but Daniel is right, it's simpler to have just conditionals. y = x >=2 ? __fls(x - 1) / 2 + 1 : 0; -- With Best Regards, Andy Shevchenko
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index a003e02..099b0d0 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -268,6 +268,18 @@ config BACKLIGHT_MAX8925 If you have a LCD backlight connected to the WLED output of MAX8925 WLED output, say Y here to enable this driver. +config BACKLIGHT_MT6370 + tristate "MediaTek MT6370 Backlight Driver" + depends on MFD_MT6370 + help + This enables support for Mediatek MT6370 Backlight driver. + It's commonly used to drive the display WLED. There are 4 channels + inside, and each channel supports up to 30mA of current capability + with 2048 current steps in exponential or linear mapping curves. + + This driver can also be built as a module. If so the module + will be called "mt6370-backlight.ko". + config BACKLIGHT_APPLE tristate "Apple Backlight Driver" depends on X86 && ACPI diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index cae2c83..e815f3f 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o obj-$(CONFIG_BACKLIGHT_LV5207LP) += lv5207lp.o obj-$(CONFIG_BACKLIGHT_MAX8925) += max8925_bl.o +obj-$(CONFIG_BACKLIGHT_MT6370) += mt6370-backlight.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o diff --git a/drivers/video/backlight/mt6370-backlight.c b/drivers/video/backlight/mt6370-backlight.c new file mode 100644 index 0000000..655f585 --- /dev/null +++ b/drivers/video/backlight/mt6370-backlight.c @@ -0,0 +1,352 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 Richtek Technology Corp. + * + * Author: ChiaEn Wu <chiaen_wu@richtek.com> + */ + +#include <linux/backlight.h> +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/kernel.h> +#include <linux/log2.h> +#include <linux/minmax.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define MT6370_REG_DEV_INFO 0x100 +#define MT6370_REG_BL_EN 0x1A0 +#define MT6370_REG_BL_BSTCTRL 0x1A1 +#define MT6370_REG_BL_PWM 0x1A2 +#define MT6370_REG_BL_DIM2 0x1A4 + +#define MT6370_VENID_MASK GENMASK(7, 4) +#define MT6370_BL_EXT_EN_MASK BIT(7) +#define MT6370_BL_EN_MASK BIT(6) +#define MT6370_BL_CONFIG_MASK BIT(0) +#define MT6370_BL_CH_MASK GENMASK(5, 2) +#define MT6370_BL_DIM2_MASK GENMASK(2, 0) +#define MT6370_BL_DUMMY_6372_MASK GENMASK(2, 0) +#define MT6370_BL_DIM2_6372_SHIFT 3 +#define MT6370_BL_PWM_EN_MASK BIT(7) +#define MT6370_BL_PWM_HYS_EN_MASK BIT(2) +#define MT6370_BL_PWM_HYS_SEL_MASK GENMASK(1, 0) +#define MT6370_BL_OVP_EN_MASK BIT(7) +#define MT6370_BL_OVP_SEL_MASK GENMASK(6, 5) +#define MT6370_BL_OC_EN_MASK BIT(3) +#define MT6370_BL_OC_SEL_MASK GENMASK(2, 1) + +#define MT6370_BL_PWM_HYS_TH_MIN_STEP 1 +#define MT6370_BL_PWM_HYS_TH_MAX_STEP 64 +#define MT6370_BL_OVP_MIN_UV 17000000 +#define MT6370_BL_OVP_MAX_UV 29000000 +#define MT6370_BL_OVP_STEP_UV 4000000 +#define MT6370_BL_OCP_MIN_UA 900000 +#define MT6370_BL_OCP_MAX_UA 1800000 +#define MT6370_BL_OCP_STEP_UA 300000 +#define MT6370_BL_MAX_BRIGHTNESS 2048 +#define MT6370_BL_MAX_CH 15 + +enum { + MT6370_VID_COMMON = 0, + MT6370_VID_6372, +}; + +struct mt6370_priv { + int vid_type; + struct backlight_device *bl; + struct device *dev; + struct gpio_desc *enable_gpio; + struct regmap *regmap; +}; + +static int mt6370_bl_update_status(struct backlight_device *bl_dev) +{ + struct mt6370_priv *priv = bl_get_data(bl_dev); + int brightness = backlight_get_brightness(bl_dev); + unsigned int enable_val; + u8 brightness_val[2]; + int ret; + + if (brightness) { + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; + brightness_val[1] = (brightness - 1) + >> fls(MT6370_BL_DIM2_MASK); + + /* + * To make MT6372 using 14 bits to control the brightness + * backward compatible with 11 bits brightness control + * (like MT6370 and MT6371 do), we left shift the value + * and pad with 1 to remaining bits. Hence, the MT6372's + * backlight brightness will be almost the same as MT6370's + * and MT6371's. + */ + if (priv->vid_type == MT6370_VID_6372) { + brightness_val[0] <<= MT6370_BL_DIM2_6372_SHIFT; + brightness_val[0] |= MT6370_BL_DUMMY_6372_MASK; + } + + ret = regmap_raw_write(priv->regmap, MT6370_REG_BL_DIM2, + brightness_val, sizeof(brightness_val)); + if (ret) + return ret; + } + + if (priv->enable_gpio) + gpiod_set_value(priv->enable_gpio, brightness ? 1 : 0); + + enable_val = brightness ? MT6370_BL_EN_MASK : 0; + return regmap_update_bits(priv->regmap, MT6370_REG_BL_EN, + MT6370_BL_EN_MASK, enable_val); +} + +static int mt6370_bl_get_brightness(struct backlight_device *bl_dev) +{ + struct mt6370_priv *priv = bl_get_data(bl_dev); + unsigned int enable; + u8 brightness_val[2]; + int brightness, ret; + + ret = regmap_read(priv->regmap, MT6370_REG_BL_EN, &enable); + if (ret) + return ret; + + if (!(enable & MT6370_BL_EN_MASK)) + return 0; + + ret = regmap_raw_read(priv->regmap, MT6370_REG_BL_DIM2, + brightness_val, sizeof(brightness_val)); + if (ret) + return ret; + + if (priv->vid_type == MT6370_VID_6372) + brightness_val[0] >>= MT6370_BL_DIM2_6372_SHIFT; + + brightness = brightness_val[1] << fls(MT6370_BL_DIM2_MASK); + brightness += (brightness_val[0] & MT6370_BL_DIM2_MASK); + + return brightness + 1; +} + +static const struct backlight_ops mt6370_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = mt6370_bl_update_status, + .get_brightness = mt6370_bl_get_brightness, +}; + +static int mt6370_init_backlight_properties(struct mt6370_priv *priv, + struct backlight_properties *props) +{ + struct device *dev = priv->dev; + u8 prop_val; + u32 brightness, ovp_uV, ocp_uA; + unsigned int mask, val; + int ret; + + /* Vendor optional properties */ + val = 0; + if (device_property_read_bool(dev, "mediatek,bled-pwm-enable")) + val |= MT6370_BL_PWM_EN_MASK; + + if (device_property_read_bool(dev, "mediatek,bled-pwm-hys-enable")) + val |= MT6370_BL_PWM_HYS_EN_MASK; + + ret = device_property_read_u8(dev, + "mediatek,bled-pwm-hys-input-th-steps", + &prop_val); + if (!ret) { + prop_val = clamp_val(prop_val, + MT6370_BL_PWM_HYS_TH_MIN_STEP, + MT6370_BL_PWM_HYS_TH_MAX_STEP); + /* + * prop_val = 1 --> 1 steps --> 0x00 + * prop_val = 2 ~ 4 --> 4 steps --> 0x01 + * prop_val = 5 ~ 16 --> 16 steps --> 0x10 + * prop_val = 17 ~ 64 --> 64 steps --> 0x11 + */ + prop_val = (ilog2(roundup_pow_of_two(prop_val)) + 1) >> 1; + val |= prop_val << (ffs(MT6370_BL_PWM_HYS_SEL_MASK) - 1); + } + + ret = regmap_update_bits(priv->regmap, MT6370_REG_BL_PWM, + val, val); + if (ret) + return ret; + + val = 0; + if (device_property_read_bool(dev, "mediatek,bled-ovp-shutdown")) + val |= MT6370_BL_OVP_EN_MASK; + + ret = device_property_read_u32(dev, "mediatek,bled-ovp-microvolt", + &ovp_uV); + if (!ret) { + ovp_uV = clamp_val(ovp_uV, MT6370_BL_OVP_MIN_UV, + MT6370_BL_OVP_MAX_UV); + ovp_uV = DIV_ROUND_UP(ovp_uV - MT6370_BL_OVP_MIN_UV, + MT6370_BL_OVP_STEP_UV); + val |= ovp_uV << (ffs(MT6370_BL_OVP_SEL_MASK) - 1); + } + + if (device_property_read_bool(dev, "mediatek,bled-ocp-shutdown")) + val |= MT6370_BL_OC_EN_MASK; + + ret = device_property_read_u32(dev, "mediatek,bled-ocp-microamp", + &ocp_uA); + if (!ret) { + ocp_uA = clamp_val(ocp_uA, MT6370_BL_OCP_MIN_UA, + MT6370_BL_OCP_MAX_UA); + ocp_uA = DIV_ROUND_UP(ocp_uA - MT6370_BL_OCP_MIN_UA, + MT6370_BL_OCP_STEP_UA); + val |= ocp_uA << (ffs(MT6370_BL_OC_SEL_MASK) - 1); + } + + ret = regmap_update_bits(priv->regmap, MT6370_REG_BL_BSTCTRL, + val, val); + if (ret) + return ret; + + /* Common properties */ + ret = device_property_read_u32(dev, "max-brightness", &brightness); + if (ret) + brightness = MT6370_BL_MAX_BRIGHTNESS; + + props->max_brightness = min_t(u32, brightness, + MT6370_BL_MAX_BRIGHTNESS); + + ret = device_property_read_u32(dev, "default-brightness", &brightness); + if (ret) + brightness = props->max_brightness; + + props->brightness = min_t(u32, brightness, props->max_brightness); + + val = 0; + prop_val = 0; + ret = device_property_read_u8(dev, "mediatek,bled-channel-use", + &prop_val); + if (ret) { + dev_err(dev, "mediatek,bled-channel-use DT property missing\n"); + return ret; + } + + if (!prop_val || prop_val > MT6370_BL_MAX_CH) { + dev_err(dev, + "No channel specified or over than upper bound (%d)\n", + prop_val); + return -EINVAL; + } + + mask = MT6370_BL_EXT_EN_MASK | MT6370_BL_CH_MASK; + val = prop_val << (ffs(MT6370_BL_CH_MASK) - 1); + + if (priv->enable_gpio) + val |= MT6370_BL_EXT_EN_MASK; + + return regmap_update_bits(priv->regmap, MT6370_REG_BL_EN, mask, val); +} + +static int mt6370_check_vendor_info(struct mt6370_priv *priv) +{ + /* + * MT6372 uses 14 bits to control the brightness but MT6370 and MT6371 + * use 11 bits. They are different so we have to use this function to + * check the vendor ID and use different methods to calculate the + * brightness. + */ + unsigned int dev_info, vid; + int ret; + + ret = regmap_read(priv->regmap, MT6370_REG_DEV_INFO, &dev_info); + if (ret) + return ret; + + vid = FIELD_GET(MT6370_VENID_MASK, dev_info); + if (vid == 0x9 || vid == 0xb) + priv->vid_type = MT6370_VID_6372; + else + priv->vid_type = MT6370_VID_COMMON; + + return 0; +} + +static int mt6370_bl_probe(struct platform_device *pdev) +{ + struct mt6370_priv *priv; + struct backlight_properties props = { + .type = BACKLIGHT_RAW, + .scale = BACKLIGHT_SCALE_LINEAR, + }; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = &pdev->dev; + + priv->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!priv->regmap) + return dev_err_probe(&pdev->dev, -ENODEV, + "Failed to get regmap\n"); + + ret = mt6370_check_vendor_info(priv); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "Failed to check vendor info\n"); + + priv->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", + GPIOD_OUT_HIGH); + if (IS_ERR(priv->enable_gpio)) + dev_err(&pdev->dev, "Failed to get 'enable' gpio\n"); + + ret = mt6370_init_backlight_properties(priv, &props); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "Failed to init backlight properties\n"); + + priv->bl = devm_backlight_device_register(&pdev->dev, pdev->name, + &pdev->dev, priv, + &mt6370_bl_ops, &props); + if (IS_ERR(priv->bl)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->bl), + "Failed to register backlight\n"); + + backlight_update_status(priv->bl); + platform_set_drvdata(pdev, priv); + + return 0; +} + +static int mt6370_bl_remove(struct platform_device *pdev) +{ + struct mt6370_priv *priv = platform_get_drvdata(pdev); + struct backlight_device *bl_dev = priv->bl; + + bl_dev->props.brightness = 0; + backlight_update_status(priv->bl); + + return 0; +} + +static const struct of_device_id __maybe_unused mt6370_bl_of_match[] = { + { .compatible = "mediatek,mt6370-backlight", }, + {} +}; +MODULE_DEVICE_TABLE(of, mt6370_bl_of_match); + +static struct platform_driver mt6370_bl_driver = { + .driver = { + .name = "mt6370-backlight", + .of_match_table = mt6370_bl_of_match, + }, + .probe = mt6370_bl_probe, + .remove = mt6370_bl_remove, +}; +module_platform_driver(mt6370_bl_driver); + +MODULE_AUTHOR("ChiaEn Wu <chiaen_wu@richtek.com>"); +MODULE_DESCRIPTION("MediaTek MT6370 Backlight Driver"); +MODULE_LICENSE("GPL v2");