[PATCH] power: regulator: Add support for regulator-force-boot-off

[Jaehoon Chung]

Hi Stefan,

On 4/8/21 6:20 PM, Stefan Roese wrote:
> From: Konstantin Porotchkin <kostap at marvell.com>
> 
> Add support for regulator-force-boot-off DT property.
> This property can be used by the board/device drivers for
> turning off regulators on early init stages as pre-requisite
> for the other components initialization.
> 
> Signed-off-by: Konstantin Porotchkin <kostap at marvell.com>
> Signed-off-by: Stefan Roese <sr at denx.de>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> Cc: Simon Glass <sjg at chromium.org>
> ---
>  drivers/power/regulator/regulator-uclass.c | 38 ++++++++++++++++++++++
>  include/power/regulator.h                  | 23 +++++++++++++
>  2 files changed, 61 insertions(+)
> 
> diff --git a/drivers/power/regulator/regulator-uclass.c b/drivers/power/regulator/regulator-uclass.c
> index 4d2e730271f9..423867edced8 100644
> --- a/drivers/power/regulator/regulator-uclass.c
> +++ b/drivers/power/regulator/regulator-uclass.c
> @@ -311,6 +311,17 @@ int regulator_autoset(struct udevice *dev)
>  	return ret;
>  }
>  
> +int regulator_unset(struct udevice *dev)
> +{
> +	struct dm_regulator_uclass_plat *uc_pdata;
> +
> +	uc_pdata = dev_get_uclass_plat(dev);
> +	if (uc_pdata->force_off)

Could you check whether uc_pdata is NULL or not?
It can be returned to NULL.

> +		return regulator_set_enable(dev, false);
> +
> +	return -EMEDIUMTYPE;
> +}
> +
>  static void regulator_show(struct udevice *dev, int ret)
>  {
>  	struct dm_regulator_uclass_plat *uc_pdata;
> @@ -443,6 +454,7 @@ static int regulator_pre_probe(struct udevice *dev)
>  	uc_pdata->boot_on = dev_read_bool(dev, "regulator-boot-on");
>  	uc_pdata->ramp_delay = dev_read_u32_default(dev, "regulator-ramp-delay",
>  						    0);
> +	uc_pdata->force_off = dev_read_bool(dev, "regulator-force-boot-off");
>  
>  	node = dev_read_subnode(dev, "regulator-state-mem");
>  	if (ofnode_valid(node)) {
> @@ -495,6 +507,32 @@ int regulators_enable_boot_on(bool verbose)
>  	return ret;
>  }
>  
> +int regulators_enable_boot_off(bool verbose)
> +{
> +	struct udevice *dev;
> +	struct uclass *uc;
> +	int ret;
> +
> +	ret = uclass_get(UCLASS_REGULATOR, &uc);
> +	if (ret)
> +		return ret;
> +	for (uclass_first_device(UCLASS_REGULATOR, &dev);
> +	     dev;

typo?

Best Regards,
Jaehoon Chung

> +	     uclass_next_device(&dev)) {
> +		ret = regulator_unset(dev);
> +		if (ret == -EMEDIUMTYPE) {
> +			ret = 0;
> +			continue;
> +		}
> +		if (verbose)
> +			regulator_show(dev, ret);
> +		if (ret == -ENOSYS)
> +			ret = 0;
> +	}
> +
> +	return ret;
> +}
> +
>  UCLASS_DRIVER(regulator) = {
>  	.id		= UCLASS_REGULATOR,
>  	.name		= "regulator",
> diff --git a/include/power/regulator.h b/include/power/regulator.h
> index da9a065bdde0..fad87c99e5db 100644
> --- a/include/power/regulator.h
> +++ b/include/power/regulator.h
> @@ -151,6 +151,7 @@ enum regulator_flag {
>   * @max_uA*    - maximum amperage (micro Amps)
>   * @always_on* - bool type, true or false
>   * @boot_on*   - bool type, true or false
> + * @force_off* - bool type, true or false
>   * TODO(sjg at chromium.org): Consider putting the above two into @flags
>   * @ramp_delay - Time to settle down after voltage change (unit: uV/us)
>   * @flags:     - flags value (see REGULATOR_FLAG_...)
> @@ -176,6 +177,7 @@ struct dm_regulator_uclass_plat {
>  	unsigned int ramp_delay;
>  	bool always_on;
>  	bool boot_on;
> +	bool force_off;
>  	const char *name;
>  	int flags;
>  	u8 ctrl_reg;
> @@ -420,6 +422,15 @@ int regulator_set_mode(struct udevice *dev, int mode_id);
>   */
>  int regulators_enable_boot_on(bool verbose);
>  
> +/**
> + * regulators_enable_boot_off() - disable regulators needed for boot
> + *
> + * This disables all regulators which are marked to be off at boot time.
> + *
> + * This effectively calls regulator_unset() for every regulator.
> + */
> +int regulators_enable_boot_off(bool verbose);
> +
>  /**
>   * regulator_autoset: setup the voltage/current on a regulator
>   *
> @@ -439,6 +450,18 @@ int regulators_enable_boot_on(bool verbose);
>   */
>  int regulator_autoset(struct udevice *dev);
>  
> +/**
> + * regulator_unset: turn off a regulator
> + *
> + * The setup depends on constraints found in device's uclass's platform data
> + * (struct dm_regulator_uclass_platdata):
> + *
> + * - Disable - will set - if  'force_off' is set to true,
> + *
> + * The function returns on the first-encountered error.
> + */
> +int regulator_unset(struct udevice *dev);
> +
>  /**
>   * regulator_autoset_by_name: setup the regulator given by its uclass's
>   * platform data name field. The setup depends on constraints found in device's
>