diff mbox series

[v6,12/13] leds: flash: mt6370: Add MediaTek MT6370 flashlight support

Message ID 20220722102407.2205-13-peterwu.pub@gmail.com (mailing list archive)
State New, archived
Headers show
Series Add MediaTek MT6370 PMIC support | expand

Commit Message

ChiaEn Wu July 22, 2022, 10:24 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.

The Flash LED in MT6370 has 2 channels and support torch/strobe mode.
Add the support of MT6370 FLASH LED.

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

v6
- Use 'GENMASK' instead of 'BIT'.
- Use dev_err_probe to decrease LOC.
- Use 'dev' variable to make probe function more clean.
- Refine the return of _mt6370_flash_brightness_set function.
- Refine the descriptions.
- Use mt6370_clamp() instead of clamp_align().
- Use device resource managed API for v4l2 flash_release.
---
 drivers/leds/flash/Kconfig             |  12 +
 drivers/leds/flash/Makefile            |   1 +
 drivers/leds/flash/leds-mt6370-flash.c | 633 +++++++++++++++++++++++++++++++++
 3 files changed, 646 insertions(+)
 create mode 100644 drivers/leds/flash/leds-mt6370-flash.c

Comments

AngeloGioacchino Del Regno July 22, 2022, 10:48 a.m. UTC | #1
Il 22/07/22 12:24, 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.
> 
> The Flash LED in MT6370 has 2 channels and support torch/strobe mode.
> Add the support of MT6370 FLASH LED.
> 
> Signed-off-by: Alice Chen <alice_chen@richtek.com>
> ---
> 
> v6
> - Use 'GENMASK' instead of 'BIT'.
> - Use dev_err_probe to decrease LOC.
> - Use 'dev' variable to make probe function more clean.
> - Refine the return of _mt6370_flash_brightness_set function.
> - Refine the descriptions.
> - Use mt6370_clamp() instead of clamp_align().
> - Use device resource managed API for v4l2 flash_release.
> ---
>   drivers/leds/flash/Kconfig             |  12 +
>   drivers/leds/flash/Makefile            |   1 +
>   drivers/leds/flash/leds-mt6370-flash.c | 633 +++++++++++++++++++++++++++++++++
>   3 files changed, 646 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..d5761ed 100644
> --- a/drivers/leds/flash/Kconfig
> +++ b/drivers/leds/flash/Kconfig
> @@ -90,4 +90,16 @@ config LEDS_SGM3140
>   	  This option enables support for the SGM3140 500mA Buck/Boost Charge
>   	  Pump LED Driver.
>   
> +config LEDS_MT6370_FLASHLIGHT
> +	tristate "Flash LED Support for MediaTek MT6370 PMIC"
> +	depends on LEDS_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".
> +
>   endif # LEDS_CLASS_FLASH
> diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
> index 0acbddc..4c4c171 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_FLASHLIGHT)	+= 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..fe439ee
> --- /dev/null
> +++ b/drivers/leds/flash/leds-mt6370-flash.c
> @@ -0,0 +1,633 @@
> +// 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)

Please fix the indentation.

> +#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)

..snip..

> +
> +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_warn(priv->dev,
> +			 "Not specified led-max-microamp, config to the minimum\n");

This should be a dev_info() instead.

> +		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_warn(priv->dev,
> +		   "Not specified flash-max-microamp, config to the minimum\n");

same here

> +		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 as min level when off to
> +	 * prevent flash current spike
> +	 */
> +	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_warn(priv->dev,
> +			 "Not specified flash-max-timeout-us, config to the minimum\n");

and same here

> +		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);
> +

Unnecessary blank line here.

> +		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" },

As common practice, write that the last element is a sentinel.

	{ /* sentinel */ },


Everything else looks good.

Regards,
Angelo
Andy Shevchenko July 25, 2022, 8:51 a.m. UTC | #2
On Fri, Jul 22, 2022 at 12:25 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
>
> 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.
>
> The Flash LED in MT6370 has 2 channels and support torch/strobe mode.
> Add the support of MT6370 FLASH LED.
>
> Signed-off-by: Alice Chen <alice_chen@richtek.com>

This SoB chain is wrong. Prioritize and read Submitting Patches!

...

> +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 prev = priv->fled_torch_used, curr;

Here and in the other functions with similar variables it seems you
never use prev after assigning curr.
Just define a single variable and use it accordingly.

> +       int ret, i;
> +
> +       mutex_lock(&priv->lock);
> +
> +       /*
> +        * Only one set of flash control logic,
> +        * use the flag to avoid strobe is currently 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 = prev | BIT(led->led_no);
> +       else
> +               curr = prev & ~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;
> +}

...

> +       struct v4l2_flash_config v4l2_config = {0};

0 is not needed.
Andy Shevchenko July 25, 2022, 8:55 a.m. UTC | #3
On Fri, Jul 22, 2022 at 12:25 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote:

Forgot to add a couple of things...

...

> +#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

Perhaps _uA would be better and consistent across your series
regarding current units.

...

> +       /*
> +        * For the flash to turn on/off, need to wait HW ramping up/down time

we need

> +        * 5ms/500us to prevent the unexpected problem.
> +        */
> +       if (!prev && curr)
> +               usleep_range(5000, 6000);
> +       else if (prev && !curr)
> +               udelay(500);

This still remains unanswered, why in the first place we allow
switching, and a busy loop in the other place?
Alice Chen July 26, 2022, 4:15 a.m. UTC | #4
Hi Andy,

>
> > +#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
>
> Perhaps _uA would be better and consistent across your series
> regarding current units.
>

Yes, _uA will be more consistent, but in general, using upper case in
the define macro is a convention, doesn't it?

>
> > +       /*
> > +        * For the flash to turn on/off, need to wait for HW ramping up/down time
>
> we need
>
> > +        * 5ms/500us to prevent the unexpected problem.
> > +        */
> > +       if (!prev && curr)
> > +               usleep_range(5000, 6000);
> > +       else if (prev && !curr)
> > +               udelay(500);
>
> This still remains unanswered, why in the first place we allow
> switching, and a busy loop in the other place?

If I refine the description to
"For the flash to turn on/off, need to wait for 5ms/500us analog settling time.
If any flash led is already used, then the analog is settled done, we
don't need to wait again."
is it answer the question?


Best regards,
Alice
Andy Shevchenko July 26, 2022, 6:10 a.m. UTC | #5
On Tue, Jul 26, 2022 at 6:15 AM szuni chen <szunichen@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
> >
> > Perhaps _uA would be better and consistent across your series
> > regarding current units.
>
> Yes, _uA will be more consistent, but in general, using upper case in
> the define macro is a convention, doesn't it?

There is general convention, but there are also:
1) common sense;
2) usage in practice (e.g. _US, etc for *seconds and _HZ for *frequency).

My common sense tells me that it is convenient to use mA,uA, etc.
Plus "in practice" it's related to use as in your series and elsewhere.

But of course it's minor to me, decide yourself.

...

> > > +       /*
> > > +        * For the flash to turn on/off, need to wait for HW ramping up/down time
> >
> > we need
> >
> > > +        * 5ms/500us to prevent the unexpected problem.
> > > +        */
> > > +       if (!prev && curr)
> > > +               usleep_range(5000, 6000);
> > > +       else if (prev && !curr)
> > > +               udelay(500);
> >
> > This still remains unanswered, why in the first place we allow
> > switching, and a busy loop in the other place?
>
> If I refine the description to
> "For the flash to turn on/off, need to wait for 5ms/500us analog settling time.
> If any flash led is already used, then the analog is settled done, we
> don't need to wait again."
> is it answer the question?

No. I'm talking from the Linux APIs perspective. There is a huge
difference between those branches. Please, conduct research, read
documentation to understand what my question is about.
Alice Chen July 29, 2022, 6:17 a.m. UTC | #6
Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月25日 週一 下午4:51寫道:
>
> On Fri, Jul 22, 2022 at 12:25 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
> >
> > 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.
> >
> > The Flash LED in MT6370 has 2 channels and support torch/strobe mode.
> > Add the support of MT6370 FLASH LED.
> >
> > Signed-off-by: Alice Chen <alice_chen@richtek.com>
>
> This SoB chain is wrong. Prioritize and read Submitting Patches!
>
Hi Andy,

After reading the Submitted Patches,
ChiaEn Wu wasn't involved in the development but he submitted the patch,
So, ChiaEn Wu <chiaen_wu@richtek.com> should be the last SoB, right?
I will revise SoB to

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

If there is anything else I need to fix, please let me know. Thank you.


Best Regards,
Szuni Chen
Andy Shevchenko July 29, 2022, 10:34 a.m. UTC | #7
On Fri, Jul 29, 2022 at 8:17 AM szuni chen <szunichen@gmail.com> wrote:
> Andy Shevchenko <andy.shevchenko@gmail.com> 於 2022年7月25日 週一 下午4:51寫道:
> > On Fri, Jul 22, 2022 at 12:25 PM ChiaEn Wu <peterwu.pub@gmail.com> wrote:
> > >
> > > From: Alice Chen <alice_chen@richtek.com>

...

> > > Signed-off-by: Alice Chen <alice_chen@richtek.com>
> >
> > This SoB chain is wrong. Prioritize and read Submitting Patches!
>
> After reading the Submitted Patches,
> ChiaEn Wu wasn't involved in the development but he submitted the patch,
> So, ChiaEn Wu <chiaen_wu@richtek.com> should be the last SoB, right?

Right. Submitter's SoB is the last SoB in the chain.

> I will revise SoB to
>
> Signed-off-by: SzuNi Chen <alice_chen@richtek.com>

Not sure I understand the SzuNi <--> Alice transformation...

> Signed-off-by: ChiaEn Wu <chiaen_wu@richtek.com>
>
> If there is anything else I need to fix, please let me know. Thank you.
Pavel Machek July 30, 2022, 9:42 p.m. UTC | #8
Hi!

> 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.
> 
> The Flash LED in MT6370 has 2 channels and support torch/strobe mode.
> Add the support of MT6370 FLASH LED.
> 
> Signed-off-by: Alice Chen <alice_chen@richtek.com>

> +config LEDS_MT6370_FLASHLIGHT
> +	tristate "Flash LED Support for MediaTek MT6370 PMIC"
> +	depends on LEDS_CLASS

I'd name it just LEDS_MT6370_FLASH.

> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2022 Richtek Technology Corp.
> + *
> + * Author: Alice Chen <alice_chen@richtek.com

Add ">" at end of line.

The series is quite big, would it be possible to submit LED changes
in separate series?

Thanks,
								Pavel
Alice Chen Aug. 4, 2022, 9:53 a.m. UTC | #9
Pavel Machek <pavel@ucw.cz> 於 2022年7月31日 週日 清晨5:42寫道:

> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (C) 2022 Richtek Technology Corp.
> > + *
> > + * Author: Alice Chen <alice_chen@richtek.com
>
> Add ">" at end of line.
>
> The series is quite big, would it be possible to submit LED changes
> in separate series?
>
Hi Pavel,

Our mfd dt-bindings depends on flash and LED dt-bindings,
but our flash and LED config depend on mfd config.
For the dependency consideration,
we think submitting them in a patch series is better.

Best Regards,
Alice
diff mbox series

Patch

diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
index d3eb689..d5761ed 100644
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -90,4 +90,16 @@  config LEDS_SGM3140
 	  This option enables support for the SGM3140 500mA Buck/Boost Charge
 	  Pump LED Driver.
 
+config LEDS_MT6370_FLASHLIGHT
+	tristate "Flash LED Support for MediaTek MT6370 PMIC"
+	depends on LEDS_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".
+
 endif # LEDS_CLASS_FLASH
diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
index 0acbddc..4c4c171 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_FLASHLIGHT)	+= 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..fe439ee
--- /dev/null
+++ b/drivers/leds/flash/leds-mt6370-flash.c
@@ -0,0 +1,633 @@ 
+// 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 prev = priv->fled_torch_used, curr;
+	int ret, i;
+
+	mutex_lock(&priv->lock);
+
+	/*
+	 * Only one set of flash control logic,
+	 * use the flag to avoid strobe is currently 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 = prev | BIT(led->led_no);
+	else
+		curr = prev & ~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)
+{
+	/*
+	 * Due to the current spike when turning on flash,
+	 * let brightness be kept by the framework.
+	 * This empty function is used to
+	 * prevent led_classdev_flash register ops check failure.
+	 */
+	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 prev = priv->fled_strobe_used, curr;
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	/*
+	 * Only one set of flash control logic,
+	 * use the flag to avoid torch is currently 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 = prev | BIT(led->led_no);
+	else
+		curr = prev & ~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 be on,
+	 * config the flash current ramping up to the setting value.
+	 * Else, always recover back 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, need to wait HW ramping up/down time
+	 * 5ms/500us to prevent the unexpected problem.
+	 */
+	if (!prev && curr)
+		usleep_range(5000, 6000);
+	else if (prev && !curr)
+		udelay(500);
+
+	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 = {0};
+	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_warn(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_warn(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 as min level when off to
+	 * prevent flash current spike
+	 */
+	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_warn(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" },
+	{}
+};
+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");