Re: [PATCH v8 1/2] leds: flash: add driver to support flash LED module in QCOM PMICs

[Fenglin Wu]

On 3/26/2023 1:36 AM, Pavel Machek wrote:
> On Fri 2023-03-03 17:50:22, Fenglin Wu wrote:
> > Add initial driver to support flash LED module found in Qualcomm
> > Technologies, Inc. PMICs. The flash module can have 3 or 4 channels
> > and each channel can be controlled indepedently and support full scale
> > current up to 1.5 A. It also supports connecting two channels together
> > to supply one LED component with full scale current up to 2 A. In that
> > case, the current will be split on each channel symmetrically and the
> > channels will be enabled and disabled at the same time.
> >
> > Signed-off-by: Fenglin Wu <quic_fenglinw@xxxxxxxxxxx>
> > Tested-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx> # sm7225-fairphone-fp4 + pm6150l
>
> > +	flash->led_cdev.brightness_set_blocking = qcom_flash_led_brightness_set;
> > +
> > +	init_data.fwnode = node;
> > +	init_data.devicename = NULL;
> > +	init_data.default_label = NULL;
> > +	init_data.devname_mandatory = false;
> > +
> > +	rc = devm_led_classdev_flash_register_ext(dev, flash, &init_data);
> > +	if (rc < 0) {
> > +		dev_err(dev, "Register flash LED classdev failed, rc=%d\n", rc);
> > +		return rc;
> > +	}
>
> I'd expect setting max_brightness somewhere around here.
>
> What does cat /sys/class/leds/*/max_brightness say (and what directory
> name are you using)?

LED_FULL is used as the default max_brightness, the driver will do the 
calculation based on LED_FULL (as below) and set the corresponding 
current when brightness is updated :

u32 current_ma = brightness * led->max_torch_current_ma / LED_FULL;

This is how max_brightness shows on my device:

# cat /sys/class/leds/white:flash-0/max_brightness
255

> BR,								Pavel