Re: [PATCH 2/2] regulator: fixed: handle startup-delay-us property

[Marco Felsch <m.felsch@pengutronix.de>]

On 26-01-29, Sascha Hauer wrote:
> The "startup-delay-us" property of the fixed regulator has never been
> handled by barebox. Handle it now.
> 
> The "startup-delay-us" property is specified as:
> 
> | startup time in microseconds
> 
> Then there's a regulator generic property "regulator-enable-ramp-delay"
> which barebox handles, specified as:
> 
> | The time taken, in microseconds, for the supply rail to
> | reach the target voltage, plus/minus whatever tolerance the board
> | design requires. This property describes the total system ramp time
> | required due to the combination of internal ramping of the regulator
> | itself, and board design issues such as trace capacitance and load
> | on the supply.
> 
> We just use the bigger of the two times as the time a regulator needs
> to become stable.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  drivers/regulator/core.c  | 9 +++++++--
>  drivers/regulator/fixed.c | 3 +++
>  include/regulator.h       | 2 ++
>  3 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 8ca937e8bd..1f8d77dc96 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -297,6 +297,7 @@ int of_regulator_register(struct regulator_dev *rdev, struct device_node *node)
>  {
>  	const char *name;
>  	int ret;
> +	u32 val = 0;
>  
>  	if (!rdev || !node)
>  		return -EINVAL;
> @@ -313,12 +314,16 @@ int of_regulator_register(struct regulator_dev *rdev, struct device_node *node)
>  
>  	if (rdev->desc->off_on_delay)
>  		rdev->off_on_delay = rdev->desc->off_on_delay;
> +	if (rdev->desc->enable_time_us)
> +		rdev->enable_time_us = rdev->desc->enable_time_us;
>  
>  	if (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1)
>  		rdev->min_uv = rdev->max_uv = rdev->desc->fixed_uV;
>  
> -	of_property_read_u32(node, "regulator-enable-ramp-delay",
> -			&rdev->enable_time_us);
> +	of_property_read_u32(node, "regulator-enable-ramp-delay", &val);
> +	if (val > rdev->enable_time_us)

Nit: Worth a comment to make it more obvious?

Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>


> +		rdev->enable_time_us = val;
> +
>  	of_property_read_u32(node, "regulator-min-microvolt",
>  			&rdev->min_uv);
>  	of_property_read_u32(node, "regulator-max-microvolt",
> diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
> index 0edb5ceb10..e00519c2fe 100644
> --- a/drivers/regulator/fixed.c
> +++ b/drivers/regulator/fixed.c
> @@ -61,6 +61,9 @@ static int regulator_fixed_probe(struct device *dev)
>  	if (!of_property_read_u32(np, "off-on-delay-us", &delay))
>  		fix->rdesc.off_on_delay = delay;
>  
> +	if (!of_property_read_u32(np, "startup-delay-us", &delay))
> +		fix->rdesc.enable_time_us = delay;
> +
>  	if (of_find_property(np, "vin-supply", NULL))
>  		fix->rdesc.supply_name = "vin";
>  
> diff --git a/include/regulator.h b/include/regulator.h
> index 09b4969c74..7ae69a7f54 100644
> --- a/include/regulator.h
> +++ b/include/regulator.h
> @@ -63,6 +63,7 @@ struct regulator_bulk_data {
>   * @volt_table: Voltage mapping table (if table based mapping)
>   * @fixed_uV: Fixed voltage of rails.
>   * @off_on_delay: guard time (in uS), before re-enabling a regulator
> + * @enable_time_us: Time taken for initial enable of regulator (in uS).
>   */
>  
>  struct regulator_desc {
> @@ -93,6 +94,7 @@ struct regulator_desc {
>  	const unsigned int *volt_table;
>  	int fixed_uV;
>  	unsigned int off_on_delay;
> +	unsigned int enable_time_us;
>  };
>  
>  /**
> 
> -- 
> 2.47.3
> 
> 
> 

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