[PATCH] led: Configure LED default-state on boot

[Patrice CHOTARD]

Hi Marek

I tested the current U-Boot master branch (22bfaa1f673ab5442dfb9778eea4c9a18dee42d0)
This patch is breaking the boot sequence on stm32mp157c-dk2.

Thanks
Patrice


On 4/4/22 01:23, Marek Vasut wrote:
> In case the DT LED subnode contains "default-state" property set to
> either "on" or "off", probe the LED driver and configure the LED state
> automatically.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Alex Nemirovsky <alex.nemirovsky at cortina-access.com>
> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Cc: Philippe Reynes <philippe.reynes at softathome.com>
> Cc: Sean Anderson <seanga2 at gmail.com>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Steven Lawrance <steven.lawrance at softathome.com>
> ---
>  drivers/led/led-uclass.c | 57 ++++++++++++++++++++++------------------
>  include/led.h            | 24 +++++++++--------
>  2 files changed, 45 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c
> index 2f4aa18fb10..5d7bf40896b 100644
> --- a/drivers/led/led-uclass.c
> +++ b/drivers/led/led-uclass.c
> @@ -66,43 +66,49 @@ int led_set_period(struct udevice *dev, int period_ms)
>  }
>  #endif
>  
> +/* This is superseded by led_post_bind()/led_post_probe() below. */
>  int led_default_state(void)
>  {
> -	struct udevice *dev;
> -	struct uclass *uc;
> -	const char *default_state;
> -	int ret;
> -
> -	ret = uclass_get(UCLASS_LED, &uc);
> -	if (ret)
> -		return ret;
> -	for (uclass_find_first_device(UCLASS_LED, &dev);
> -	     dev;
> -	     uclass_find_next_device(&dev)) {
> -		default_state = dev_read_string(dev, "default-state");
> -		if (!default_state)
> -			continue;
> -		ret = device_probe(dev);
> -		if (ret)
> -			return ret;
> -		if (!strncmp(default_state, "on", 2))
> -			led_set_state(dev, LEDST_ON);
> -		else if (!strncmp(default_state, "off", 3))
> -			led_set_state(dev, LEDST_OFF);
> -		/* default-state = "keep" : device is only probed */
> -	}
> -
> -	return ret;
> +	return 0;
>  }
>  
>  static int led_post_bind(struct udevice *dev)
>  {
>  	struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
> +	const char *default_state;
>  
>  	uc_plat->label = dev_read_string(dev, "label");
>  	if (!uc_plat->label)
>  		uc_plat->label = ofnode_get_name(dev_ofnode(dev));
>  
> +	uc_plat->default_state = LEDST_COUNT;
> +
> +	default_state = dev_read_string(dev, "default-state");
> +	if (!default_state)
> +		return 0;
> +
> +	if (!strncmp(default_state, "on", 2))
> +		uc_plat->default_state = LEDST_ON;
> +	else if (!strncmp(default_state, "off", 3))
> +		uc_plat->default_state = LEDST_OFF;
> +	else
> +		return 0;
> +
> +	/*
> +	 * In case the LED has default-state DT property, trigger
> +	 * probe() to configure its default state during startup.
> +	 */
> +	return device_probe(dev);
> +}
> +
> +static int led_post_probe(struct udevice *dev)
> +{
> +	struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
> +
> +	if (uc_plat->default_state == LEDST_ON ||
> +	    uc_plat->default_state == LEDST_OFF)
> +		led_set_state(dev, uc_plat->default_state);
> +
>  	return 0;
>  }
>  
> @@ -111,4 +117,5 @@ UCLASS_DRIVER(led) = {
>  	.name		= "led",
>  	.per_device_plat_auto	= sizeof(struct led_uc_plat),
>  	.post_bind	= led_post_bind,
> +	.post_probe	= led_post_probe,
>  };
> diff --git a/include/led.h b/include/led.h
> index 8eeb5a7c6d3..43acca85719 100644
> --- a/include/led.h
> +++ b/include/led.h
> @@ -9,13 +9,26 @@
>  
>  struct udevice;
>  
> +enum led_state_t {
> +	LEDST_OFF = 0,
> +	LEDST_ON = 1,
> +	LEDST_TOGGLE,
> +#ifdef CONFIG_LED_BLINK
> +	LEDST_BLINK,
> +#endif
> +
> +	LEDST_COUNT,
> +};
> +
>  /**
>   * struct led_uc_plat - Platform data the uclass stores about each device
>   *
>   * @label:	LED label
> + * @default_state:	LED default state
>   */
>  struct led_uc_plat {
>  	const char *label;
> +	enum led_state_t default_state;
>  };
>  
>  /**
> @@ -27,17 +40,6 @@ struct led_uc_priv {
>  	int period_ms;
>  };
>  
> -enum led_state_t {
> -	LEDST_OFF = 0,
> -	LEDST_ON = 1,
> -	LEDST_TOGGLE,
> -#ifdef CONFIG_LED_BLINK
> -	LEDST_BLINK,
> -#endif
> -
> -	LEDST_COUNT,
> -};
> -
>  struct led_ops {
>  	/**
>  	 * set_state() - set the state of an LED