diff mbox series

[v9,09/10] leds: flash: mt6370: Add MediaTek MT6370 flashlight support

Message ID 20220830034042.9354-10-peterwu.pub@gmail.com (mailing list archive)
State New, archived
Headers show
Series Add MediaTek MT6370 PMIC support | expand

Commit Message

ChiaEn Wu Aug. 30, 2022, 3:40 a.m. UTC
From: Alice Chen <alice_chen@richtek.com>

The MediaTek MT6370 is a highly-integrated smart power management IC,
which includes a single cell Li-Ion/Li-Polymer switching battery
charger, a USB Type-C & Power Delivery (PD) controller, dual Flash
LED current sources, a RGB LED driver, a backlight WLED driver,
a display bias driver and a general LDO for portable devices.

Add support for the MT6370 Flash LED driver. Flash LED in MT6370
has 2 channels and support torch/strobe mode.

Signed-off-by: Alice Chen <alice_chen@richtek.com>
Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.com>
---

v9
- Revise the format of the comments.
---
 drivers/leds/flash/Kconfig             |  14 +
 drivers/leds/flash/Makefile            |   1 +
 drivers/leds/flash/leds-mt6370-flash.c | 632 +++++++++++++++++++++++++++++++++
 3 files changed, 647 insertions(+)
 create mode 100644 drivers/leds/flash/leds-mt6370-flash.c

Comments

AngeloGioacchino Del Regno Aug. 30, 2022, 8:49 a.m. UTC | #1
Il 30/08/22 05:40, ChiaEn Wu ha scritto:
> From: Alice Chen <alice_chen@richtek.com>
> 
> The MediaTek MT6370 is a highly-integrated smart power management IC,
> which includes a single cell Li-Ion/Li-Polymer switching battery
> charger, a USB Type-C & Power Delivery (PD) controller, dual Flash
> LED current sources, a RGB LED driver, a backlight WLED driver,
> a display bias driver and a general LDO for portable devices.
> 
> Add support for the MT6370 Flash LED driver. Flash LED in MT6370
> has 2 channels and support torch/strobe mode.
> 
> Signed-off-by: Alice Chen <alice_chen@richtek.com>
> Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.com>
> ---
> 
> v9
> - Revise the format of the comments.
> ---
>   drivers/leds/flash/Kconfig             |  14 +
>   drivers/leds/flash/Makefile            |   1 +
>   drivers/leds/flash/leds-mt6370-flash.c | 632 +++++++++++++++++++++++++++++++++
>   3 files changed, 647 insertions(+)
>   create mode 100644 drivers/leds/flash/leds-mt6370-flash.c
> 
> diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
> index d3eb689..405bd16 100644
> --- a/drivers/leds/flash/Kconfig
> +++ b/drivers/leds/flash/Kconfig
> @@ -61,6 +61,20 @@ config LEDS_MT6360
>   	  Independent current sources supply for each flash LED support torch
>   	  and strobe mode.
>   
> +config LEDS_MT6370_FLASH
> +	tristate "Flash LED Support for MediaTek MT6370 PMIC"
> +	depends on LEDS_CLASS && OF
> +	depends on LEDS_CLASS_FLASH || !LEDS_CLASS_FLASH
> +	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
> +	depends on MFD_MT6370
> +	help
> +	  Support 2 channels and torch/strobe mode.
> +	  Say Y here to enable support for
> +	  MT6370_FLASH_LED device.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called "leds-mt6370-flash".
> +
>   config LEDS_RT4505
>   	tristate "LED support for RT4505 flashlight controller"
>   	depends on I2C && OF
> diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
> index 0acbddc..0c1f3c5 100644
> --- a/drivers/leds/flash/Makefile
> +++ b/drivers/leds/flash/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_LEDS_MAX77693)	+= leds-max77693.o
>   obj-$(CONFIG_LEDS_RT4505)	+= leds-rt4505.o
>   obj-$(CONFIG_LEDS_RT8515)	+= leds-rt8515.o
>   obj-$(CONFIG_LEDS_SGM3140)	+= leds-sgm3140.o
> +obj-$(CONFIG_LEDS_MT6370_FLASH)	+= leds-mt6370-flash.o
> diff --git a/drivers/leds/flash/leds-mt6370-flash.c b/drivers/leds/flash/leds-mt6370-flash.c
> new file mode 100644
> index 0000000..a8ec7e1
> --- /dev/null
> +++ b/drivers/leds/flash/leds-mt6370-flash.c
> @@ -0,0 +1,632 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2022 Richtek Technology Corp.
> + *
> + * Author: Alice Chen <alice_chen@richtek.com>
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/led-class-flash.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +
> +#include <media/v4l2-flash-led-class.h>
> +
> +enum {
> +	MT6370_LED_FLASH1,
> +	MT6370_LED_FLASH2,
> +	MT6370_MAX_LEDS
> +};
> +
> +/* Virtual definition for multicolor */
> +
> +#define MT6370_REG_FLEDEN		0x17E
> +#define MT6370_REG_STRBTO		0x173
> +#define MT6370_REG_CHGSTAT2		0x1D1
> +#define MT6370_REG_FLEDSTAT1		0x1D9
> +#define MT6370_REG_FLEDISTRB(_id)	(0x174 + 4 * (_id))
> +#define MT6370_REG_FLEDITOR(_id)	(0x175 + 4 * (_id))
> +#define MT6370_ITORCH_MASK		GENMASK(4, 0)
> +#define MT6370_ISTROBE_MASK		GENMASK(6, 0)
> +#define MT6370_STRBTO_MASK		GENMASK(6, 0)
> +#define MT6370_TORCHEN_MASK		BIT(3)
> +#define MT6370_STROBEN_MASK		BIT(2)
> +#define MT6370_FLCSEN_MASK(_id)		BIT(MT6370_LED_FLASH2 - (_id))
> +#define MT6370_FLCSEN_MASK_ALL		GENMASK(1, 0)
> +#define MT6370_FLEDCHGVINOVP_MASK	BIT(3)
> +#define MT6370_FLED1STRBTO_MASK		BIT(11)
> +#define MT6370_FLED2STRBTO_MASK		BIT(10)
> +#define MT6370_FLED1STRB_MASK		BIT(9)
> +#define MT6370_FLED2STRB_MASK		BIT(8)
> +#define MT6370_FLED1SHORT_MASK		BIT(7)
> +#define MT6370_FLED2SHORT_MASK		BIT(6)
> +#define MT6370_FLEDLVF_MASK		BIT(3)
> +
> +#define MT6370_LED_JOINT		2
> +#define MT6370_RANGE_FLED_REG		4
> +#define MT6370_ITORCH_MIN_uA		25000
> +#define MT6370_ITORCH_STEP_uA		12500
> +#define MT6370_ITORCH_MAX_uA		400000
> +#define MT6370_ITORCH_DOUBLE_MAX_uA	800000
> +#define MT6370_ISTRB_MIN_uA		50000
> +#define MT6370_ISTRB_STEP_uA		12500
> +#define MT6370_ISTRB_MAX_uA		1500000
> +#define MT6370_ISTRB_DOUBLE_MAX_uA	3000000
> +#define MT6370_STRBTO_MIN_US		64000
> +#define MT6370_STRBTO_STEP_US		32000
> +#define MT6370_STRBTO_MAX_US		2432000
> +
> +#define STATE_OFF			0
> +#define STATE_KEEP			1
> +#define STATE_ON			2
> +
> +#define to_mt6370_led(ptr, member) container_of(ptr, struct mt6370_led, member)
> +
> +struct mt6370_led {
> +	struct led_classdev_flash flash;
> +	struct v4l2_flash *v4l2_flash;
> +	struct mt6370_priv *priv;
> +	u32 led_no;

The maximum value that we will ever see for `led_no` is 2: this means
that we don't need 32 full bits here.

	u8 led_no;

> +	u32 default_state;

This should be...

	enum led_default_state default_state;

...but then, you're never using this variable as far as I can see, apart from
initializing it in mt6370_init_common_properties, for which, there's a comment
below.

In any case, please either fix the initialization and actually make use of
this variable, or remove it entirely.

> +};
> +
> +struct mt6370_priv {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	struct mutex lock;
> +	unsigned int fled_strobe_used;
> +	unsigned int fled_torch_used;
> +	unsigned int leds_active;
> +	unsigned int leds_count;
> +	struct mt6370_led leds[];
> +};
> +
> +static int mt6370_torch_brightness_set(struct led_classdev *lcdev,
> +				       enum led_brightness level)
> +{
> +	struct mt6370_led *led = to_mt6370_led(lcdev, flash.led_cdev);
> +	struct mt6370_priv *priv = led->priv;
> +	u32 led_enable_mask = (led->led_no == MT6370_LED_JOINT) ?
> +			      MT6370_FLCSEN_MASK_ALL :
> +			      MT6370_FLCSEN_MASK(led->led_no);
> +	u32 enable_mask = MT6370_TORCHEN_MASK | led_enable_mask;
> +	u32 val = level ? led_enable_mask : 0;
> +	u32 curr;
> +	int ret, i;
> +
> +	mutex_lock(&priv->lock);
> +
> +	/*
> +	 * There is only one set of flash control logic, and this
> +	 * flag is used to check if 'strobe' is currently being used.
> +	 */
> +	if (priv->fled_strobe_used) {
> +		dev_warn(lcdev->dev, "Please disable strobe first [%d]\n",
> +			 priv->fled_strobe_used);
> +		ret = -EBUSY;
> +		goto unlock;
> +	}
> +
> +	if (level)
> +		curr = priv->fled_torch_used | BIT(led->led_no);
> +	else
> +		curr = priv->fled_torch_used & ~BIT(led->led_no);
> +
> +	if (curr)
> +		val |= MT6370_TORCHEN_MASK;
> +
> +	if (level) {
> +		level -= 1;
> +		if (led->led_no == MT6370_LED_JOINT) {
> +			int flevel[MT6370_MAX_LEDS];
> +
> +			flevel[0] = level / 2;
> +			flevel[1] = level - flevel[0];
> +			for (i = 0; i < MT6370_MAX_LEDS; i++) {
> +				ret = regmap_update_bits(priv->regmap,
> +						MT6370_REG_FLEDITOR(i),
> +						MT6370_ITORCH_MASK, flevel[i]);
> +				if (ret)
> +					goto unlock;
> +			}
> +		} else {
> +			ret = regmap_update_bits(priv->regmap,
> +					MT6370_REG_FLEDITOR(led->led_no),
> +					MT6370_ITORCH_MASK, level);
> +			if (ret)
> +				goto unlock;
> +		}
> +	}
> +
> +	ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN,
> +				 enable_mask, val);
> +	if (ret)
> +		goto unlock;
> +
> +	priv->fled_torch_used = curr;
> +
> +unlock:
> +	mutex_unlock(&priv->lock);
> +	return ret;
> +}
> +
> +static int mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev,
> +				       u32 brightness)
> +{
> +	/*
> +	 * Because of the current spikes when turning on the flash,
> +	 * the brightness should be kept by the LED framework. This
> +	 * empty function is used to prevent checking failure when
> +	 * led_classdev_flash registers ops.
> +	 */
> +	return 0;
> +}
> +
> +static int _mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev,
> +					u32 brightness)
> +{
> +	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
> +	struct mt6370_priv *priv = led->priv;
> +	struct led_flash_setting *s = &fl_cdev->brightness;
> +	u32 val = (brightness - s->min) / s->step;
> +	int ret, i;
> +
> +	if (led->led_no == MT6370_LED_JOINT) {
> +		int flevel[MT6370_MAX_LEDS];

Since you're writing this value to registers, please use fixed size variables.
If this is really supposed to be a signed value, it would be:

		s32 flevel[MT6370_MAX_LEDS];

> +
> +		flevel[0] = val / 2;
> +		flevel[1] = val - flevel[0];
> +		for (i = 0; i < MT6370_MAX_LEDS; i++) {
> +			ret = regmap_update_bits(priv->regmap,
> +						 MT6370_REG_FLEDISTRB(i),
> +						 MT6370_ISTROBE_MASK, flevel[i]);
> +			if (ret)
> +				return ret;
> +		}
> +	} else {
> +		return regmap_update_bits(priv->regmap,
> +					  MT6370_REG_FLEDISTRB(led->led_no),
> +					  MT6370_ISTROBE_MASK, val);
> +	}
> +
> +	return 0;

If we reach this point, this means that led_no is out of range (which is never
supposed to happen - I know).
Since that condition is something unexpected and unhandled, you should return
an error here.

> +}
> +
> +static int mt6370_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
> +{
> +	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
> +	struct mt6370_priv *priv = led->priv;
> +	struct led_classdev *lcdev = &fl_cdev->led_cdev;
> +	struct led_flash_setting *s = &fl_cdev->brightness;
> +	u32 led_enable_mask = (led->led_no == MT6370_LED_JOINT) ?
> +			      MT6370_FLCSEN_MASK_ALL :
> +			      MT6370_FLCSEN_MASK(led->led_no);
> +	u32 enable_mask = MT6370_STROBEN_MASK | led_enable_mask;
> +	u32 val = state ? led_enable_mask : 0;
> +	u32 curr;
> +	int ret;
> +
> +	mutex_lock(&priv->lock);
> +
> +	/*
> +	 * There is only one set of flash control logic, and this
> +	 * flag is used to check if 'torch' is currently being used.
> +	 */
> +	if (priv->fled_torch_used) {
> +		dev_warn(lcdev->dev, "Please disable torch first [0x%x]\n",
> +				      priv->fled_torch_used);
> +		ret = -EBUSY;
> +		goto unlock;
> +	}
> +
> +	if (state)
> +		curr = priv->fled_strobe_used | BIT(led->led_no);
> +	else
> +		curr = priv->fled_strobe_used & ~BIT(led->led_no);
> +
> +	if (curr)
> +		val |= MT6370_STROBEN_MASK;
> +
> +	ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask,
> +				 val);
> +	if (ret) {
> +		dev_err(lcdev->dev, "[%d] control current source %d fail\n",
> +				     led->led_no, state);
> +		goto unlock;
> +	}
> +
> +	/*
> +	 * If the flash needs to turn on, configure the flash current to
> +	 * ramp up to the setting value. Otherwise, always revert to the
> +	 * minimum one.
> +	 */
> +	ret = _mt6370_flash_brightness_set(fl_cdev, state ? s->val : s->min);
> +	if (ret)
> +		goto unlock;

If this fails, I think that we should revert the previous changes to FLEDEN
before returning.

> +
> +	/*
> +	 * For the flash to turn on/off, we must wait for HW ramping
> +	 * up/down time 5ms/500us to prevent the unexpected problem.
> +	 */
> +	if (!priv->fled_strobe_used && curr)
> +		usleep_range(5000, 6000);
> +	else if (priv->fled_strobe_used && !curr)
> +		usleep_range(500, 600);
> +
> +	priv->fled_strobe_used = curr;
> +
> +unlock:
> +	mutex_unlock(&priv->lock);
> +	return ret;
> +}
> +

..snip..

> +
> +static int mt6370_init_common_properties(struct mt6370_led *led,
> +					 struct led_init_data *init_data)
> +{
> +	const char * const states[] = { "off", "keep", "on" };
> +	const char *str = states[STATE_OFF];
> +	int ret;
> +
> +	fwnode_property_read_string(init_data->fwnode, "default-state", &str);
> +	ret = match_string(states, ARRAY_SIZE(states), str);
> +	if (ret >= 0)
> +		led->default_state = ret;
> +
> +	return 0;
> +}
> +
> +static int mt6370_led_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mt6370_priv *priv;
> +	struct fwnode_handle *child;
> +	size_t count;
> +	int i = 0, ret;
> +
> +	count = device_get_child_node_count(dev);
> +	if (!count || count > MT6370_MAX_LEDS)
> +		return dev_err_probe(dev, -EINVAL,
> +		       "No child node or node count over max led number %zu\n", count);
> +
> +	priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->leds_count = count;
> +	priv->dev = dev;
> +	mutex_init(&priv->lock);
> +
> +	priv->regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!priv->regmap)
> +		return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
> +
> +	device_for_each_child_node(dev, child) {
> +		struct mt6370_led *led = priv->leds + i;
> +		struct led_init_data init_data = { .fwnode = child, };
> +
> +		led->priv = priv;
> +		ret = mt6370_init_common_properties(led, &init_data);

This is only initializing the default state, for which you do have a helper.

Please use led_init_default_state_get(fwnode).

> +		if (ret)
> +			return ret;
> +
> +		ret = mt6370_init_flash_properties(led, &init_data);
> +		if (ret)
> +			return ret;
> +
> +		ret = mt6370_led_register(dev, led, &init_data);
> +		if (ret)
> +			return ret;
> +
> +		i++;
> +	}
> +
> +	return 0;
> +}
> +

Regards,
Angelo
ChiaEn Wu Sept. 21, 2022, 1:48 a.m. UTC | #2
On Sun, Sep 18, 2022 at 3:22 AM Han Jingoo <jingoohan1@gmail.com> wrote:
>
> On Mon, Aug 29, 2022 ChiaEn Wu <peterwu.pub@gmail.com> wrote:

...

> > +#define MT6370_ITORCH_MIN_uA           25000
> > +#define MT6370_ITORCH_STEP_uA          12500
> > +#define MT6370_ITORCH_MAX_uA           400000
> > +#define MT6370_ITORCH_DOUBLE_MAX_uA    800000
> > +#define MT6370_ISTRB_MIN_uA            50000
> > +#define MT6370_ISTRB_STEP_uA           12500
> > +#define MT6370_ISTRB_MAX_uA            1500000
> > +#define MT6370_ISTRB_DOUBLE_MAX_uA     3000000
>
> Use upper letters as below:
>
> #define MT6370_ITORCH_MIN_UA           25000
> #define MT6370_ITORCH_STEP_UA          12500
> #define MT6370_ITORCH_MAX_UA           400000
> #define MT6370_ITORCH_DOUBLE_MAX_UA    800000
> #define MT6370_ISTRB_MIN_UA            50000
> #define MT6370_ISTRB_STEP_UA           12500
> #define MT6370_ISTRB_MAX_UA            1500000
> #define MT6370_ISTRB_DOUBLE_MAX_UA     3000000
>
>
> > +#define MT6370_STRBTO_MIN_US           64000
> > +#define MT6370_STRBTO_STEP_US          32000
> > +#define MT6370_STRBTO_MAX_US           2432000
> > +

Hi Jingoo,

This coding style is in accordance with Andy's opinion in this mail:
https://lore.kernel.org/linux-arm-kernel/CAHp75Vciq4M4kVrabNV9vTLLcd1vR=bMe8JLEdAF9MkRTpcB5g@mail.gmail.com/

And I will revise other parts in v12.
Thanks for your review!

--
Best Regards,
ChiaEn Wu
Andy Shevchenko Sept. 21, 2022, 11:47 a.m. UTC | #3
On Wed, Sep 21, 2022 at 4:48 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
> On Sun, Sep 18, 2022 at 3:22 AM Han Jingoo <jingoohan1@gmail.com> wrote:
> > On Mon, Aug 29, 2022 ChiaEn Wu <peterwu.pub@gmail.com> wrote:

> > > +#define MT6370_ITORCH_MIN_uA           25000
> > > +#define MT6370_ITORCH_STEP_uA          12500
> > > +#define MT6370_ITORCH_MAX_uA           400000
> > > +#define MT6370_ITORCH_DOUBLE_MAX_uA    800000
> > > +#define MT6370_ISTRB_MIN_uA            50000
> > > +#define MT6370_ISTRB_STEP_uA           12500
> > > +#define MT6370_ISTRB_MAX_uA            1500000
> > > +#define MT6370_ISTRB_DOUBLE_MAX_uA     3000000
> >
> > Use upper letters as below:

For microseconds (and other -seconds) the common practice (I assume
historically) is to use upper letters, indeed. But for current it's
more natural to use small letters for unit multiplier as it's easier
to read and understand.

> > #define MT6370_ITORCH_MIN_UA           25000
> > #define MT6370_ITORCH_STEP_UA          12500
> > #define MT6370_ITORCH_MAX_UA           400000
> > #define MT6370_ITORCH_DOUBLE_MAX_UA    800000
> > #define MT6370_ISTRB_MIN_UA            50000
> > #define MT6370_ISTRB_STEP_UA           12500
> > #define MT6370_ISTRB_MAX_UA            1500000
> > #define MT6370_ISTRB_DOUBLE_MAX_UA     3000000
> >
> > > +#define MT6370_STRBTO_MIN_US           64000
> > > +#define MT6370_STRBTO_STEP_US          32000
> > > +#define MT6370_STRBTO_MAX_US           2432000
>
> Hi Jingoo,
>
> This coding style is in accordance with Andy's opinion in this mail:
> https://lore.kernel.org/linux-arm-kernel/CAHp75Vciq4M4kVrabNV9vTLLcd1vR=bMe8JLEdAF9MkRTpcB5g@mail.gmail.com/

True.
Han Jingoo Sept. 23, 2022, 9:34 p.m. UTC | #4
On Wed, Sep 21, 2022 Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>
> On Wed, Sep 21, 2022 at 4:48 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
> > On Sun, Sep 18, 2022 at 3:22 AM Han Jingoo <jingoohan1@gmail.com> wrote:
> > > On Mon, Aug 29, 2022 ChiaEn Wu <peterwu.pub@gmail.com> wrote:
>
> > > > +#define MT6370_ITORCH_MIN_uA           25000
> > > > +#define MT6370_ITORCH_STEP_uA          12500
> > > > +#define MT6370_ITORCH_MAX_uA           400000
> > > > +#define MT6370_ITORCH_DOUBLE_MAX_uA    800000
> > > > +#define MT6370_ISTRB_MIN_uA            50000
> > > > +#define MT6370_ISTRB_STEP_uA           12500
> > > > +#define MT6370_ISTRB_MAX_uA            1500000
> > > > +#define MT6370_ISTRB_DOUBLE_MAX_uA     3000000
> > >
> > > Use upper letters as below:
>
> For microseconds (and other -seconds) the common practice (I assume
> historically) is to use upper letters, indeed. But for current it's
> more natural to use small letters for unit multiplier as it's easier
> to read and understand.

(CC'ed Linus Torvalds, Andrew Morton, Joe Perches, Julia Lawall,
Krzysztof Kozlowski,)

Yep, it is common practice. Long time ago, I met the same problem on
how to present micro-ampere:
visibility vs coding practice. At that time, I followed the coding
practice. So, was there anyone who
rejected this decision to mix upper and lower letters when you gave
your comment last July?
If there is no objection, or most of maintainers and long-term
contributors agree with that,
I am ok with that.

To Tovalds, Andrew, Joe, Julia, Krzysztof,

I just need your feedback on coding styles. Are you ok with mixing
upper and lower letters for visibility
to present micro-seconds or micro-ampere? Andy (one of very-active
contributors) gives his opinion that
mixing upper and lower letters can be acceptable. I remain neutral on
this coding style issue.

e.g., #define MT6370_ITORCH_DOUBLE_MAX_uA    800000

Thank you.

Best regards,
Jingoo Han

>
> > > #define MT6370_ITORCH_MIN_UA           25000
> > > #define MT6370_ITORCH_STEP_UA          12500
> > > #define MT6370_ITORCH_MAX_UA           400000
> > > #define MT6370_ITORCH_DOUBLE_MAX_UA    800000
> > > #define MT6370_ISTRB_MIN_UA            50000
> > > #define MT6370_ISTRB_STEP_UA           12500
> > > #define MT6370_ISTRB_MAX_UA            1500000
> > > #define MT6370_ISTRB_DOUBLE_MAX_UA     3000000
> > >
> > > > +#define MT6370_STRBTO_MIN_US           64000
> > > > +#define MT6370_STRBTO_STEP_US          32000
> > > > +#define MT6370_STRBTO_MAX_US           2432000
> >
> > Hi Jingoo,
> >
> > This coding style is in accordance with Andy's opinion in this mail:
> > https://lore.kernel.org/linux-arm-kernel/CAHp75Vciq4M4kVrabNV9vTLLcd1vR=bMe8JLEdAF9MkRTpcB5g@mail.gmail.com/
>
> True.
>
> --
> With Best Regards,
> Andy Shevchenko
Joe Perches Sept. 23, 2022, 10:02 p.m. UTC | #5
On Fri, 2022-09-23 at 14:34 -0700, Han Jingoo wrote:
> On Wed, Sep 21, 2022 Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> > 
> > On Wed, Sep 21, 2022 at 4:48 AM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
> > > On Sun, Sep 18, 2022 at 3:22 AM Han Jingoo <jingoohan1@gmail.com> wrote:
> > > > On Mon, Aug 29, 2022 ChiaEn Wu <peterwu.pub@gmail.com> wrote:
> > 
> > > > > +#define MT6370_ITORCH_MIN_uA           25000
> > > > > +#define MT6370_ITORCH_STEP_uA          12500
> > > > > +#define MT6370_ITORCH_MAX_uA           400000
> > > > > +#define MT6370_ITORCH_DOUBLE_MAX_uA    800000
> > > > > +#define MT6370_ISTRB_MIN_uA            50000
> > > > > +#define MT6370_ISTRB_STEP_uA           12500
> > > > > +#define MT6370_ISTRB_MAX_uA            1500000
> > > > > +#define MT6370_ISTRB_DOUBLE_MAX_uA     3000000
> > > > 
> > > > Use upper letters as below:
> > 
> > For microseconds (and other -seconds) the common practice (I assume
> > historically) is to use upper letters, indeed. But for current it's
> > more natural to use small letters for unit multiplier as it's easier
> > to read and understand.

I think it's fine. see:

commit 22735ce857a2d9f4e6eec37c36be3fcf9d21d154
Author: Joe Perches <joe@perches.com>
Date:   Wed Jul 3 15:05:33 2013 -0700

    checkpatch: ignore SI unit CamelCase variants like "_uV"
    
    Many existing variable names use SI like variants that should be otherwise
    obvious and acceptable.
diff mbox series

Patch

diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
index d3eb689..405bd16 100644
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -61,6 +61,20 @@  config LEDS_MT6360
 	  Independent current sources supply for each flash LED support torch
 	  and strobe mode.
 
+config LEDS_MT6370_FLASH
+	tristate "Flash LED Support for MediaTek MT6370 PMIC"
+	depends on LEDS_CLASS && OF
+	depends on LEDS_CLASS_FLASH || !LEDS_CLASS_FLASH
+	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
+	depends on MFD_MT6370
+	help
+	  Support 2 channels and torch/strobe mode.
+	  Say Y here to enable support for
+	  MT6370_FLASH_LED device.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called "leds-mt6370-flash".
+
 config LEDS_RT4505
 	tristate "LED support for RT4505 flashlight controller"
 	depends on I2C && OF
diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
index 0acbddc..0c1f3c5 100644
--- a/drivers/leds/flash/Makefile
+++ b/drivers/leds/flash/Makefile
@@ -9,3 +9,4 @@  obj-$(CONFIG_LEDS_MAX77693)	+= leds-max77693.o
 obj-$(CONFIG_LEDS_RT4505)	+= leds-rt4505.o
 obj-$(CONFIG_LEDS_RT8515)	+= leds-rt8515.o
 obj-$(CONFIG_LEDS_SGM3140)	+= leds-sgm3140.o
+obj-$(CONFIG_LEDS_MT6370_FLASH)	+= leds-mt6370-flash.o
diff --git a/drivers/leds/flash/leds-mt6370-flash.c b/drivers/leds/flash/leds-mt6370-flash.c
new file mode 100644
index 0000000..a8ec7e1
--- /dev/null
+++ b/drivers/leds/flash/leds-mt6370-flash.c
@@ -0,0 +1,632 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Richtek Technology Corp.
+ *
+ * Author: Alice Chen <alice_chen@richtek.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include <media/v4l2-flash-led-class.h>
+
+enum {
+	MT6370_LED_FLASH1,
+	MT6370_LED_FLASH2,
+	MT6370_MAX_LEDS
+};
+
+/* Virtual definition for multicolor */
+
+#define MT6370_REG_FLEDEN		0x17E
+#define MT6370_REG_STRBTO		0x173
+#define MT6370_REG_CHGSTAT2		0x1D1
+#define MT6370_REG_FLEDSTAT1		0x1D9
+#define MT6370_REG_FLEDISTRB(_id)	(0x174 + 4 * (_id))
+#define MT6370_REG_FLEDITOR(_id)	(0x175 + 4 * (_id))
+#define MT6370_ITORCH_MASK		GENMASK(4, 0)
+#define MT6370_ISTROBE_MASK		GENMASK(6, 0)
+#define MT6370_STRBTO_MASK		GENMASK(6, 0)
+#define MT6370_TORCHEN_MASK		BIT(3)
+#define MT6370_STROBEN_MASK		BIT(2)
+#define MT6370_FLCSEN_MASK(_id)		BIT(MT6370_LED_FLASH2 - (_id))
+#define MT6370_FLCSEN_MASK_ALL		GENMASK(1, 0)
+#define MT6370_FLEDCHGVINOVP_MASK	BIT(3)
+#define MT6370_FLED1STRBTO_MASK		BIT(11)
+#define MT6370_FLED2STRBTO_MASK		BIT(10)
+#define MT6370_FLED1STRB_MASK		BIT(9)
+#define MT6370_FLED2STRB_MASK		BIT(8)
+#define MT6370_FLED1SHORT_MASK		BIT(7)
+#define MT6370_FLED2SHORT_MASK		BIT(6)
+#define MT6370_FLEDLVF_MASK		BIT(3)
+
+#define MT6370_LED_JOINT		2
+#define MT6370_RANGE_FLED_REG		4
+#define MT6370_ITORCH_MIN_uA		25000
+#define MT6370_ITORCH_STEP_uA		12500
+#define MT6370_ITORCH_MAX_uA		400000
+#define MT6370_ITORCH_DOUBLE_MAX_uA	800000
+#define MT6370_ISTRB_MIN_uA		50000
+#define MT6370_ISTRB_STEP_uA		12500
+#define MT6370_ISTRB_MAX_uA		1500000
+#define MT6370_ISTRB_DOUBLE_MAX_uA	3000000
+#define MT6370_STRBTO_MIN_US		64000
+#define MT6370_STRBTO_STEP_US		32000
+#define MT6370_STRBTO_MAX_US		2432000
+
+#define STATE_OFF			0
+#define STATE_KEEP			1
+#define STATE_ON			2
+
+#define to_mt6370_led(ptr, member) container_of(ptr, struct mt6370_led, member)
+
+struct mt6370_led {
+	struct led_classdev_flash flash;
+	struct v4l2_flash *v4l2_flash;
+	struct mt6370_priv *priv;
+	u32 led_no;
+	u32 default_state;
+};
+
+struct mt6370_priv {
+	struct device *dev;
+	struct regmap *regmap;
+	struct mutex lock;
+	unsigned int fled_strobe_used;
+	unsigned int fled_torch_used;
+	unsigned int leds_active;
+	unsigned int leds_count;
+	struct mt6370_led leds[];
+};
+
+static int mt6370_torch_brightness_set(struct led_classdev *lcdev,
+				       enum led_brightness level)
+{
+	struct mt6370_led *led = to_mt6370_led(lcdev, flash.led_cdev);
+	struct mt6370_priv *priv = led->priv;
+	u32 led_enable_mask = (led->led_no == MT6370_LED_JOINT) ?
+			      MT6370_FLCSEN_MASK_ALL :
+			      MT6370_FLCSEN_MASK(led->led_no);
+	u32 enable_mask = MT6370_TORCHEN_MASK | led_enable_mask;
+	u32 val = level ? led_enable_mask : 0;
+	u32 curr;
+	int ret, i;
+
+	mutex_lock(&priv->lock);
+
+	/*
+	 * There is only one set of flash control logic, and this
+	 * flag is used to check if 'strobe' is currently being used.
+	 */
+	if (priv->fled_strobe_used) {
+		dev_warn(lcdev->dev, "Please disable strobe first [%d]\n",
+			 priv->fled_strobe_used);
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	if (level)
+		curr = priv->fled_torch_used | BIT(led->led_no);
+	else
+		curr = priv->fled_torch_used & ~BIT(led->led_no);
+
+	if (curr)
+		val |= MT6370_TORCHEN_MASK;
+
+	if (level) {
+		level -= 1;
+		if (led->led_no == MT6370_LED_JOINT) {
+			int flevel[MT6370_MAX_LEDS];
+
+			flevel[0] = level / 2;
+			flevel[1] = level - flevel[0];
+			for (i = 0; i < MT6370_MAX_LEDS; i++) {
+				ret = regmap_update_bits(priv->regmap,
+						MT6370_REG_FLEDITOR(i),
+						MT6370_ITORCH_MASK, flevel[i]);
+				if (ret)
+					goto unlock;
+			}
+		} else {
+			ret = regmap_update_bits(priv->regmap,
+					MT6370_REG_FLEDITOR(led->led_no),
+					MT6370_ITORCH_MASK, level);
+			if (ret)
+				goto unlock;
+		}
+	}
+
+	ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN,
+				 enable_mask, val);
+	if (ret)
+		goto unlock;
+
+	priv->fled_torch_used = curr;
+
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static int mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev,
+				       u32 brightness)
+{
+	/*
+	 * Because of the current spikes when turning on the flash,
+	 * the brightness should be kept by the LED framework. This
+	 * empty function is used to prevent checking failure when
+	 * led_classdev_flash registers ops.
+	 */
+	return 0;
+}
+
+static int _mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev,
+					u32 brightness)
+{
+	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+	struct mt6370_priv *priv = led->priv;
+	struct led_flash_setting *s = &fl_cdev->brightness;
+	u32 val = (brightness - s->min) / s->step;
+	int ret, i;
+
+	if (led->led_no == MT6370_LED_JOINT) {
+		int flevel[MT6370_MAX_LEDS];
+
+		flevel[0] = val / 2;
+		flevel[1] = val - flevel[0];
+		for (i = 0; i < MT6370_MAX_LEDS; i++) {
+			ret = regmap_update_bits(priv->regmap,
+						 MT6370_REG_FLEDISTRB(i),
+						 MT6370_ISTROBE_MASK, flevel[i]);
+			if (ret)
+				return ret;
+		}
+	} else {
+		return regmap_update_bits(priv->regmap,
+					  MT6370_REG_FLEDISTRB(led->led_no),
+					  MT6370_ISTROBE_MASK, val);
+	}
+
+	return 0;
+}
+
+static int mt6370_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
+{
+	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+	struct mt6370_priv *priv = led->priv;
+	struct led_classdev *lcdev = &fl_cdev->led_cdev;
+	struct led_flash_setting *s = &fl_cdev->brightness;
+	u32 led_enable_mask = (led->led_no == MT6370_LED_JOINT) ?
+			      MT6370_FLCSEN_MASK_ALL :
+			      MT6370_FLCSEN_MASK(led->led_no);
+	u32 enable_mask = MT6370_STROBEN_MASK | led_enable_mask;
+	u32 val = state ? led_enable_mask : 0;
+	u32 curr;
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	/*
+	 * There is only one set of flash control logic, and this
+	 * flag is used to check if 'torch' is currently being used.
+	 */
+	if (priv->fled_torch_used) {
+		dev_warn(lcdev->dev, "Please disable torch first [0x%x]\n",
+				      priv->fled_torch_used);
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	if (state)
+		curr = priv->fled_strobe_used | BIT(led->led_no);
+	else
+		curr = priv->fled_strobe_used & ~BIT(led->led_no);
+
+	if (curr)
+		val |= MT6370_STROBEN_MASK;
+
+	ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask,
+				 val);
+	if (ret) {
+		dev_err(lcdev->dev, "[%d] control current source %d fail\n",
+				     led->led_no, state);
+		goto unlock;
+	}
+
+	/*
+	 * If the flash needs to turn on, configure the flash current to
+	 * ramp up to the setting value. Otherwise, always revert to the
+	 * minimum one.
+	 */
+	ret = _mt6370_flash_brightness_set(fl_cdev, state ? s->val : s->min);
+	if (ret)
+		goto unlock;
+
+	/*
+	 * For the flash to turn on/off, we must wait for HW ramping
+	 * up/down time 5ms/500us to prevent the unexpected problem.
+	 */
+	if (!priv->fled_strobe_used && curr)
+		usleep_range(5000, 6000);
+	else if (priv->fled_strobe_used && !curr)
+		usleep_range(500, 600);
+
+	priv->fled_strobe_used = curr;
+
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static int mt6370_strobe_get(struct led_classdev_flash *fl_cdev, bool *state)
+{
+	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+	struct mt6370_priv *priv = led->priv;
+
+	mutex_lock(&priv->lock);
+	*state = !!(priv->fled_strobe_used & BIT(led->led_no));
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int mt6370_timeout_set(struct led_classdev_flash *fl_cdev, u32 timeout)
+{
+	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+	struct mt6370_priv *priv = led->priv;
+	struct led_flash_setting *s = &fl_cdev->timeout;
+	u32 val = (timeout - s->min) / s->step;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_update_bits(priv->regmap, MT6370_REG_STRBTO,
+				 MT6370_STRBTO_MASK, val);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int mt6370_fault_get(struct led_classdev_flash *fl_cdev, u32 *fault)
+{
+	struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+	struct mt6370_priv *priv = led->priv;
+	u16 fled_stat;
+	unsigned int chg_stat, strobe_timeout_mask, fled_short_mask;
+	u32 rfault = 0;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_read(priv->regmap, MT6370_REG_CHGSTAT2, &chg_stat);
+	if (ret)
+		goto unlock;
+
+	ret = regmap_raw_read(priv->regmap, MT6370_REG_FLEDSTAT1, &fled_stat,
+			      sizeof(fled_stat));
+	if (ret)
+		goto unlock;
+
+	switch (led->led_no) {
+	case MT6370_LED_FLASH1:
+		strobe_timeout_mask = MT6370_FLED1STRBTO_MASK;
+		fled_short_mask = MT6370_FLED1SHORT_MASK;
+		break;
+
+	case MT6370_LED_FLASH2:
+		strobe_timeout_mask = MT6370_FLED2STRBTO_MASK;
+		fled_short_mask = MT6370_FLED2SHORT_MASK;
+		break;
+
+	case MT6370_LED_JOINT:
+		strobe_timeout_mask = MT6370_FLED1STRBTO_MASK |
+				      MT6370_FLED2STRBTO_MASK;
+		fled_short_mask = MT6370_FLED1SHORT_MASK |
+				  MT6370_FLED2SHORT_MASK;
+	}
+
+	if (chg_stat & MT6370_FLEDCHGVINOVP_MASK)
+		rfault |= LED_FAULT_INPUT_VOLTAGE;
+
+	if (fled_stat & strobe_timeout_mask)
+		rfault |= LED_FAULT_TIMEOUT;
+
+	if (fled_stat & fled_short_mask)
+		rfault |= LED_FAULT_SHORT_CIRCUIT;
+
+	if (fled_stat & MT6370_FLEDLVF_MASK)
+		rfault |= LED_FAULT_UNDER_VOLTAGE;
+
+	*fault = rfault;
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static const struct led_flash_ops mt6370_flash_ops = {
+	.flash_brightness_set = mt6370_flash_brightness_set,
+	.strobe_set = mt6370_strobe_set,
+	.strobe_get = mt6370_strobe_get,
+	.timeout_set = mt6370_timeout_set,
+	.fault_get = mt6370_fault_get,
+};
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static int mt6370_flash_external_strobe_set(struct v4l2_flash *v4l2_flash,
+					    bool enable)
+{
+	struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+	struct mt6370_led *led = to_mt6370_led(flash, flash);
+	struct mt6370_priv *priv = led->priv;
+	u32 mask = (led->led_no == MT6370_LED_JOINT) ? MT6370_FLCSEN_MASK_ALL :
+		   MT6370_FLCSEN_MASK(led->led_no);
+	u32 val = enable ? mask : 0;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, mask, val);
+	if (ret)
+		goto unlock;
+
+	if (enable)
+		priv->fled_strobe_used |= BIT(led->led_no);
+	else
+		priv->fled_strobe_used &= ~BIT(led->led_no);
+
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static const struct v4l2_flash_ops v4l2_flash_ops = {
+	.external_strobe_set = mt6370_flash_external_strobe_set,
+};
+
+static void mt6370_init_v4l2_flash_config(struct mt6370_led *led,
+					  struct v4l2_flash_config *config)
+{
+	struct led_classdev *lcdev;
+	struct led_flash_setting *s = &config->intensity;
+
+	lcdev = &led->flash.led_cdev;
+
+	s->min = MT6370_ITORCH_MIN_uA;
+	s->step = MT6370_ITORCH_STEP_uA;
+	s->val = s->max = s->min + (lcdev->max_brightness - 1) * s->step;
+
+	config->has_external_strobe = 1;
+	strscpy(config->dev_name, lcdev->dev->kobj.name,
+		sizeof(config->dev_name));
+
+	config->flash_faults = LED_FAULT_SHORT_CIRCUIT | LED_FAULT_TIMEOUT |
+			       LED_FAULT_INPUT_VOLTAGE |
+			       LED_FAULT_UNDER_VOLTAGE;
+}
+#else
+static const struct v4l2_flash_ops v4l2_flash_ops;
+static void mt6370_init_v4l2_flash_config(struct mt6370_led *led,
+					  struct v4l2_flash_config *config)
+{
+}
+#endif
+
+static void mt6370_v4l2_flash_release(void *v4l2_flash)
+{
+	v4l2_flash_release(v4l2_flash);
+}
+
+static int mt6370_led_register(struct device *parent, struct mt6370_led *led,
+				struct led_init_data *init_data)
+{
+	struct v4l2_flash_config v4l2_config = {};
+	int ret;
+
+	ret = devm_led_classdev_flash_register_ext(parent, &led->flash,
+						   init_data);
+	if (ret)
+		return dev_err_probe(parent, ret,
+				     "Couldn't register flash %d\n", led->led_no);
+
+	mt6370_init_v4l2_flash_config(led, &v4l2_config);
+	led->v4l2_flash = v4l2_flash_init(parent, init_data->fwnode,
+					  &led->flash, &v4l2_flash_ops,
+					  &v4l2_config);
+	if (IS_ERR(led->v4l2_flash))
+		return dev_err_probe(parent, PTR_ERR(led->v4l2_flash),
+				     "Failed to register %d v4l2 sd\n", led->led_no);
+
+	return devm_add_action_or_reset(parent, mt6370_v4l2_flash_release,
+					led->v4l2_flash);
+}
+
+static u32 mt6370_clamp(u32 val, u32 min, u32 max, u32 step)
+{
+	u32 retval;
+
+	retval = clamp_val(val, min, max);
+	if (step > 1)
+		retval = rounddown(retval - min, step) + min;
+
+	return retval;
+}
+
+static int mt6370_init_flash_properties(struct mt6370_led *led,
+					struct led_init_data *init_data)
+{
+	struct led_classdev_flash *flash = &led->flash;
+	struct led_classdev *lcdev = &flash->led_cdev;
+	struct mt6370_priv *priv = led->priv;
+	struct led_flash_setting *s;
+	u32 sources[MT6370_MAX_LEDS];
+	u32 max_uA, val;
+	int i, ret, num;
+
+	num = fwnode_property_count_u32(init_data->fwnode, "led-sources");
+	if (num < 1 || num > MT6370_MAX_LEDS)
+		return dev_err_probe(priv->dev, -EINVAL,
+				     "Not specified or wrong number of led-sources\n");
+
+	ret = fwnode_property_read_u32_array(init_data->fwnode, "led-sources", sources, num);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < num; i++) {
+		if (sources[i] >= MT6370_MAX_LEDS)
+			return -EINVAL;
+		if (priv->leds_active & BIT(sources[i]))
+			return -EINVAL;
+		priv->leds_active |= BIT(sources[i]);
+
+	}
+	led->led_no = (num == MT6370_MAX_LEDS) ? MT6370_LED_JOINT :
+		       sources[0];
+
+	max_uA = (num == 2) ? MT6370_ITORCH_DOUBLE_MAX_uA : MT6370_ITORCH_MAX_uA;
+	ret = fwnode_property_read_u32(init_data->fwnode, "led-max-microamp", &val);
+	if (ret) {
+		dev_info(priv->dev,
+			 "Not specified led-max-microamp, config to the minimum\n");
+		val = MT6370_ITORCH_MIN_uA;
+	} else {
+		val = mt6370_clamp(val, MT6370_ITORCH_MIN_uA, max_uA,
+				  MT6370_ITORCH_STEP_uA);
+	}
+
+	lcdev->max_brightness = (val - MT6370_ITORCH_MIN_uA) /
+				MT6370_ITORCH_STEP_uA + 1;
+	lcdev->brightness_set_blocking = mt6370_torch_brightness_set;
+	lcdev->flags |= LED_DEV_CAP_FLASH;
+
+	max_uA = (num == 2) ? MT6370_ISTRB_DOUBLE_MAX_uA : MT6370_ISTRB_MAX_uA;
+	ret = fwnode_property_read_u32(init_data->fwnode, "flash-max-microamp", &val);
+	if (ret) {
+		dev_info(priv->dev,
+		   "Not specified flash-max-microamp, config to the minimum\n");
+		val = MT6370_ISTRB_MIN_uA;
+	} else {
+		val = mt6370_clamp(val, MT6370_ISTRB_MIN_uA, max_uA,
+				  MT6370_ISTRB_STEP_uA);
+	}
+
+	s = &flash->brightness;
+	s->min = MT6370_ISTRB_MIN_uA;
+	s->step = MT6370_ISTRB_STEP_uA;
+	s->val = s->max = val;
+
+	/*
+	 * Always configure to the minimum level when
+	 * off to prevent flash current spikes.
+	 */
+	ret = _mt6370_flash_brightness_set(flash, s->min);
+	if (ret)
+		return ret;
+
+	ret = fwnode_property_read_u32(init_data->fwnode,
+				       "flash-max-timeout-us", &val);
+	if (ret) {
+		dev_info(priv->dev,
+			 "Not specified flash-max-timeout-us, config to the minimum\n");
+		val = MT6370_STRBTO_MIN_US;
+	} else {
+		val = mt6370_clamp(val, MT6370_STRBTO_MIN_US,
+				   MT6370_STRBTO_MAX_US, MT6370_STRBTO_STEP_US);
+	}
+
+	s = &flash->timeout;
+	s->min = MT6370_STRBTO_MIN_US;
+	s->step = MT6370_STRBTO_STEP_US;
+	s->val = s->max = val;
+
+	flash->ops = &mt6370_flash_ops;
+
+	return 0;
+}
+
+static int mt6370_init_common_properties(struct mt6370_led *led,
+					 struct led_init_data *init_data)
+{
+	const char * const states[] = { "off", "keep", "on" };
+	const char *str = states[STATE_OFF];
+	int ret;
+
+	fwnode_property_read_string(init_data->fwnode, "default-state", &str);
+	ret = match_string(states, ARRAY_SIZE(states), str);
+	if (ret >= 0)
+		led->default_state = ret;
+
+	return 0;
+}
+
+static int mt6370_led_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mt6370_priv *priv;
+	struct fwnode_handle *child;
+	size_t count;
+	int i = 0, ret;
+
+	count = device_get_child_node_count(dev);
+	if (!count || count > MT6370_MAX_LEDS)
+		return dev_err_probe(dev, -EINVAL,
+		       "No child node or node count over max led number %zu\n", count);
+
+	priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->leds_count = count;
+	priv->dev = dev;
+	mutex_init(&priv->lock);
+
+	priv->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!priv->regmap)
+		return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
+
+	device_for_each_child_node(dev, child) {
+		struct mt6370_led *led = priv->leds + i;
+		struct led_init_data init_data = { .fwnode = child, };
+
+		led->priv = priv;
+		ret = mt6370_init_common_properties(led, &init_data);
+		if (ret)
+			return ret;
+
+		ret = mt6370_init_flash_properties(led, &init_data);
+		if (ret)
+			return ret;
+
+		ret = mt6370_led_register(dev, led, &init_data);
+		if (ret)
+			return ret;
+
+		i++;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id mt6370_led_of_id[] = {
+	{ .compatible = "mediatek,mt6370-flashlight" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mt6370_led_of_id);
+
+static struct platform_driver mt6370_led_driver = {
+	.driver = {
+		.name = "mt6370-flashlight",
+		.of_match_table = mt6370_led_of_id,
+	},
+	.probe = mt6370_led_probe,
+};
+module_platform_driver(mt6370_led_driver);
+
+MODULE_AUTHOR("Alice Chen <alice_chen@richtek.com>");
+MODULE_DESCRIPTION("MT6370 FLASH LED Driver");
+MODULE_LICENSE("GPL v2");