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

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Date:   Sat, 25 Mar 2023 18:09:57 +0100
From:   Pavel Machek <pavel@....cz>
To:     Fenglin Wu <quic_fenglinw@...cinc.com>
Cc:     linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        lee@...nel.org, krzysztof.kozlowski@...aro.org,
        linux-leds@...r.kernel.org, quic_collinsd@...cinc.com,
        quic_subbaram@...cinc.com, Luca Weiss <luca.weiss@...rphone.com>
Subject: Re: [PATCH v8 1/2] leds: flash: add driver to support flash LED
 module in QCOM PMICs

Hi!
> @@ -61,6 +61,21 @@ config LEDS_MT6360
>  	  Independent current sources supply for each flash LED support torch
>  	  and strobe mode.
>  
> +config LEDS_QCOM_FLASH
> +	tristate "LED support for flash module inside Qualcomm Technologies, Inc. PMIC"
> +	depends on MFD_SPMI_PMIC || COMPILE_TEST
> +	depends on LEDS_CLASS && OF
> +	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
> +	select REGMAP
> +	help
> +	  This option enables support for the flash module found in Qualcomm
> +	  Technologies, Inc. PMICs. The flash module can have 3 or 4 flash LED
> +	  channels and each channel is programmable to support up to 1.5 A full
> +	  scale current. It also supports connecting two channels' output together
> +	  to supply one LED component to achieve current up to 2 A. In such case,
> +	  the total LED current will be split symmetrically on each channel and
> +	  they will be enabled/disabled at the same time.

"This can be built as a module, module will be called..."

> +static int qcom_flash_led_brightness_set(struct led_classdev *led_cdev,
> +					enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
> +	struct qcom_flash_led *led = flcdev_to_qcom_fled(fled_cdev);
> +	u32 current_ma = brightness * led->max_torch_current_ma / LED_FULL;
> +	bool enable = !!brightness;
> +	int rc;
> +
> +	rc = set_flash_current(led, current_ma, TORCH_MODE);
> +	if (rc)
> +		return rc;

I'd not mind supporting more than one brightness level -- AFAICT hw can do that.

BR,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html