Hi Simon,
Am Freitag, 6. August 2021, 10:02:44 CEST schrieb Simon Xue:
> From: David Wu <david.wu@xxxxxxxxxxxxxx>
>
> Add voltage notifier, no need to query regulator voltage for
> every saradc read, just get regulator voltage once at probe.
>
> Signed-off-by: Simon Xue <xxm@xxxxxxxxxxxxxx>
> Signed-off-by: David Wu <david.wu@xxxxxxxxxxxxxx>
thanks for picking up the suggestion for the regulator notifier :-) .
Please also adapt the commit message to include that information though
and please also increase the versioning ... this definitly isn't v1 ;-) .
One more thing down below.
> ---
> drivers/iio/adc/rockchip_saradc.c | 35 ++++++++++++++++++++++++-------
> 1 file changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index f3eb8d2e50dc..d8b0954aeb43 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c
> @@ -49,10 +49,12 @@ struct rockchip_saradc {
> struct clk *clk;
> struct completion completion;
> struct regulator *vref;
> + int uv_vref;
> struct reset_control *reset;
> const struct rockchip_saradc_data *data;
> u16 last_val;
> const struct iio_chan_spec *last_chan;
> + struct notifier_block nb;
> };
>
> static void rockchip_saradc_power_down(struct rockchip_saradc *info)
> @@ -105,13 +107,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
> mutex_unlock(&indio_dev->mlock);
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SCALE:
> - ret = regulator_get_voltage(info->vref);
> - if (ret < 0) {
> - dev_err(&indio_dev->dev, "failed to get voltage\n");
> - return ret;
> - }
> -
> - *val = ret / 1000;
> + *val = info->uv_vref / 1000;
> *val2 = chan->scan_type.realbits;
> return IIO_VAL_FRACTIONAL_LOG2;
> default:
> @@ -298,6 +294,19 @@ static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
> return IRQ_HANDLED;
> }
>
> +static int rockchip_saradc_volt_notify(struct notifier_block *nb,
> + unsigned long event,
> + void *data)
> +{
> + struct rockchip_saradc *info =
> + container_of(nb, struct rockchip_saradc, nb);
> +
> + if (event & REGULATOR_EVENT_VOLTAGE_CHANGE)
> + info->uv_vref = (unsigned long)data;
> +
> + return NOTIFY_OK;
> +}
> +
You probably want an devm-action to unregister the notifier
on device removal. Something like this and the addition in _probe().
static void rockchip_saradc_regulator_action(void *data)
{
struct rockchip_saradc *info = data;
regulator_unregister_notifier(info->vref, &info->nb);
}
> static int rockchip_saradc_probe(struct platform_device *pdev)
> {
> struct rockchip_saradc *info = NULL;
> @@ -410,6 +419,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
> return ret;
> }
>
> + info->uv_vref = regulator_get_voltage(info->vref);
> + if (info->uv_vref < 0) {
> + dev_err(&pdev->dev, "failed to get voltage\n");
> + ret = info->uv_vref;
> + return ret;
> + }
> +
> ret = clk_prepare_enable(info->pclk);
> if (ret < 0) {
> dev_err(&pdev->dev, "failed to enable pclk\n");
> @@ -450,6 +466,11 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + info->nb.notifier_call = rockchip_saradc_volt_notify;
> + ret = regulator_register_notifier(info->vref, &info->nb);
> + if (ret)
> + return ret;
> +
ret = devm_add_action_or_reset(&pdev->dev, rockchip_saradc_regulator_action, info);
if (ret)
goto ret;
This ties the unregistration nicely into the devm-framework and thus
doesn't require any additional error handling, as the "action" is also
directly called if devm_add_action fails.
Heiko
> return devm_iio_device_register(&pdev->dev, indio_dev);
> }
>
>
