Re: [PATCH v3 09/13] leds: flash: add support for Samsung S2M series PMIC flash LED device

[Lee Jones]

On Sat, 14 Mar 2026, Kaustabh Chakraborty wrote:

> On 2026-03-10 11:38 +00:00, Lee Jones wrote:
> > On Wed, 25 Feb 2026, Kaustabh Chakraborty wrote:
> >
> >> Add support for flash LEDs found in certain Samsung S2M series PMICs.
> >> The device has two channels for LEDs, typically for the back and front
> >> cameras in mobile devices. Both channels can be independently
> >> controlled, and can be operated in torch or flash modes.
> >> 
> >> The driver includes initial support for the S2MU005 PMIC flash LEDs.
> >> 
> >> Signed-off-by: Kaustabh Chakraborty <kauschluss@xxxxxxxxxxx>
> >> ---
> >>  drivers/leds/flash/Kconfig          |  12 +
> >>  drivers/leds/flash/Makefile         |   1 +
> >>  drivers/leds/flash/leds-s2m-flash.c | 429 ++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 442 insertions(+)
> >> 
> >> diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
> >> index 5e08102a67841..be62e05277429 100644
> >> --- a/drivers/leds/flash/Kconfig
> >> +++ b/drivers/leds/flash/Kconfig
> >> @@ -114,6 +114,18 @@ config LEDS_RT8515
> >>  	  To compile this driver as a module, choose M here: the module
> >>  	  will be called leds-rt8515.
> >>  
> >> +config LEDS_S2M_FLASH
> >> +	tristate "Samsung S2M series PMICs flash/torch LED support"
> >> +	depends on LEDS_CLASS
> >> +	depends on MFD_SEC_CORE
> >> +	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
> >> +	select REGMAP_IRQ
> >> +	help
> >> +	  This option enables support for the flash/torch LEDs found in
> >> +	  certain Samsung S2M series PMICs, such as the S2MU005. It has
> >> +	  a LED channel dedicated for every physical LED. The LEDs can
> >> +	  be controlled in flash and torch modes.
> >> +
> >>  config LEDS_SGM3140
> >>  	tristate "LED support for the SGM3140"
> >>  	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
> >> diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
> >> index 712fb737a428e..44e6c1b4beb37 100644
> >> --- a/drivers/leds/flash/Makefile
> >> +++ b/drivers/leds/flash/Makefile
> >> @@ -10,6 +10,7 @@ obj-$(CONFIG_LEDS_MAX77693)	+= leds-max77693.o
> >>  obj-$(CONFIG_LEDS_QCOM_FLASH)	+= leds-qcom-flash.o
> >>  obj-$(CONFIG_LEDS_RT4505)	+= leds-rt4505.o
> >>  obj-$(CONFIG_LEDS_RT8515)	+= leds-rt8515.o
> >> +obj-$(CONFIG_LEDS_S2M_FLASH)	+= leds-s2m-flash.o
> >>  obj-$(CONFIG_LEDS_SGM3140)	+= leds-sgm3140.o
> >>  obj-$(CONFIG_LEDS_SY7802)	+= leds-sy7802.o
> >>  obj-$(CONFIG_LEDS_TPS6131X)	+= leds-tps6131x.o

[...]

> >> +static int s2mu005_fled_torch_brightness_set(struct led_classdev *cdev,
> >> +					     enum led_brightness value)
> >> +{
> >> +	struct s2m_fled *priv = to_led_priv(to_cdev_flash(cdev));
> >> +	struct regmap *regmap = priv->regmap;
> >> +	int ret;
> >> +
> >> +	mutex_lock(&priv->lock);
> >> +
> >> +	if (value == LED_OFF) {
> >
> > These defines are deprecated.
> >
> > From include/linux/leds.h:
> >
> > /* This is obsolete/useless. We now support variable maximum brightness. */
> > enum led_brightness {
> >         LED_OFF         = 0,
> >         LED_ON          = 1,
> >         LED_HALF        = 127,
> >         LED_FULL        = 255,
> > };
> >
> 
> Let me know what am I supposed to use then. The
> brightness_set_blocking() function is defined as such:
> 
> 	int (*brightness_set_blocking)(struct led_classdev *led_cdev,
> 				       enum led_brightness brightness);
> 
> Which has enum led_brightness as one of its params.
> 
> Do I just ignore the 'obsolete' param for now and replace ` == LED_OFF`
> with a logical NOT?

I'm pretty sure most places just treat this as a u8 these days.

-- 
Lee Jones [李琼斯]