Re: [PATCH v2] video: simple-panel: add regulator support

[Sascha Hauer <s.hauer@pengutronix.de>]

On Sun, Jan 26, 2025 at 10:46:14PM +0100, Michael Grzeschik wrote:
> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
> ---
> v1 -> v2: added the missging signed-off-by
> 
>  drivers/video/simple-panel.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/video/simple-panel.c b/drivers/video/simple-panel.c
> index 7048e2f51b..d4c6874987 100644
> --- a/drivers/video/simple-panel.c
> +++ b/drivers/video/simple-panel.c
> @@ -10,6 +10,7 @@
>  #include <linux/err.h>
>  #include <of.h>
>  #include <fb.h>
> +#include <regulator.h>
>  #include <gpio.h>
>  #include <of_gpio.h>
>  #include <video/backlight.h>
> @@ -25,6 +26,7 @@ struct simple_panel {
>  	struct device_node *backlight_node;
>  	struct backlight_device *backlight;
>  	struct device_node *ddc_node;
> +	struct regulator *power;
>  	int enable_delay;
>  };
>  
> @@ -49,6 +51,8 @@ static int simple_panel_enable(struct simple_panel *panel)
>  	if (panel->enable_delay)
>  		mdelay(panel->enable_delay);
>  
> +	regulator_enable(panel->power);
> +
>  	if (panel->backlight) {
>  		ret = backlight_set_brightness_default(panel->backlight);
>  		if (ret)
> @@ -65,6 +69,8 @@ static int simple_panel_disable(struct simple_panel *panel)
>  	if (panel->backlight)
>  		backlight_set_brightness(panel->backlight, 0);
>  
> +	regulator_disable(panel->power);
> +
>  	if (gpio_is_valid(panel->enable_gpio))
>  		gpio_direction_output(panel->enable_gpio,
>  			!panel->enable_active_high);
> @@ -154,6 +160,10 @@ static int simple_panel_probe(struct device *dev)
>  
>  	panel->backlight_node = of_parse_phandle(node, "backlight", 0);
>  
> +	panel->power = regulator_get(dev, "power");
> +	if (IS_ERR(panel->power))
> +		dev_warn(dev, "Cannot find regulator\n");

When there's an error you should return it.
regulator_enable()/regulator_disable() do not handle error pointers
gracefully.

Sascha

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