Re: [PATCH v2 3/7] regulator: sy7636a: wait for power good on enable

[Andreas Kemnade <andreas@kemnade.info>]

On Sun,  1 Nov 2026 22:31:21 +0000
Pablo Mazzini <pmazzini@gmail.com> wrote:

> Wait for power good on enable, as the TPS65185 and FP9931 drivers do,
> so that consumers can use the rails once the enable returns.
> 
> Signed-off-by: Pablo Mazzini <pmazzini@gmail.com>

Reviewed-by: Andreas Kemnade <andreas@kemnade.info>

Regards,
Andreas

> ---
>  drivers/regulator/sy7636a-regulator.c | 52 +++++++++++++++++++++++++--
>  1 file changed, 50 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/regulator/sy7636a-regulator.c b/drivers/regulator/sy7636a-regulator.c
> index 382bab017784..f87144e921da 100644
> --- a/drivers/regulator/sy7636a-regulator.c
> +++ b/drivers/regulator/sy7636a-regulator.c
> @@ -7,8 +7,10 @@
>  // Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
>  //          Alistair Francis <alistair@alistair23.me>
>  
> +#include <linux/completion.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/i2c.h>
> +#include <linux/interrupt.h>
>  #include <linux/mfd/sy7636a.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
> @@ -17,11 +19,14 @@
>  #include <linux/regulator/machine.h>
>  #include <linux/regmap.h>
>  
> +#define PGOOD_TIMEOUT_MSECS 200
> +
>  struct sy7636a_data {
>  	struct regmap *regmap;
>  	struct gpio_desc *pgood_gpio;
>  	struct gpio_desc *en_gpio;
>  	struct gpio_desc *vcom_en_gpio;
> +	struct completion pgood_completion;
>  };
>  
>  static int sy7636a_get_vcom_voltage_sel(struct regulator_dev *rdev)
> @@ -65,12 +70,43 @@ static int sy7636a_get_status(struct regulator_dev *rdev)
>  	return ret;
>  }
>  
> +static irqreturn_t sy7636a_pgood_handler(int irq, void *dev_id)
> +{
> +	struct sy7636a_data *data = dev_id;
> +
> +	complete(&data->pgood_completion);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/* return once the rails are good, so that consumers can use them */
> +static int sy7636a_enable(struct regulator_dev *rdev)
> +{
> +	struct sy7636a_data *data = dev_get_drvdata(rdev->dev.parent);
> +	int ret;
> +
> +	reinit_completion(&data->pgood_completion);
> +	ret = regulator_enable_regmap(rdev);
> +	if (ret)
> +		return ret;
> +
> +	wait_for_completion_timeout(&data->pgood_completion,
> +				    msecs_to_jiffies(PGOOD_TIMEOUT_MSECS));
> +	ret = gpiod_get_value_cansleep(data->pgood_gpio);
> +	if (ret <= 0) {
> +		regulator_disable_regmap(rdev);
> +		return ret ? ret : -ETIMEDOUT;
> +	}
> +
> +	return 0;
> +}
> +
>  static const struct regulator_ops sy7636a_vcom_volt_ops = {
>  	.list_voltage = regulator_list_voltage_linear_range,
>  	.map_voltage = regulator_map_voltage_linear_range,
>  	.get_voltage_sel = sy7636a_get_vcom_voltage_sel,
>  	.set_voltage_sel = sy7636a_set_vcom_voltage_sel,
> -	.enable = regulator_enable_regmap,
> +	.enable = sy7636a_enable,
>  	.disable = regulator_disable_regmap,
>  	.is_enabled = regulator_is_enabled_regmap,
>  	.get_status = sy7636a_get_status,
> @@ -104,7 +140,7 @@ static int sy7636a_regulator_probe(struct platform_device *pdev)
>  	struct regulator_dev *rdev;
>  	struct gpio_desc *gdp;
>  	struct sy7636a_data *data;
> -	int ret;
> +	int irq, ret;
>  
>  	if (!regmap)
>  		return -EPROBE_DEFER;
> @@ -156,6 +192,18 @@ static int sy7636a_regulator_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	irq = gpiod_to_irq(data->pgood_gpio);
> +	if (irq < 0)
> +		return dev_err_probe(&pdev->dev, irq, "no power good interrupt\n");
> +
> +	init_completion(&data->pgood_completion);
> +	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, sy7636a_pgood_handler,
> +					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> +					"sy7636a-pgood", data);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret,
> +				     "failed to request power good interrupt\n");
> +
>  	config.dev = &pdev->dev;
>  	config.regmap = regmap;
>