Re: [PATCH v2 5/5] iio: sx9310: Enable vdd and svdd regulators at probe

Doug Anderson
2020-07-24T22:02:38Z

Hi,

On Fri, Jul 24, 2020 at 2:33 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Enable the main power supply (vdd) and digital IO power supply (svdd)
> during probe so that the i2c communication and device works properly on
> boards that aggressively power gate these supplies.
>
> Cc: Gwendal Grignou <gwendal@chromium.org>
> Cc: Daniel Campello <campello@chromium.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
> Cc: Douglas Anderson <dianders@chromium.org>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
> drivers/iio/proximity/sx9310.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
> index 1e1f6bba50f6..ad6ed100c7a6 100644
> --- a/drivers/iio/proximity/sx9310.c
> +++ b/drivers/iio/proximity/sx9310.c
> @@ -19,6 +19,7 @@
> #include <linux/of.h>
> #include <linux/pm.h>
> #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/slab.h>
>
> #include <linux/iio/buffer.h>
> @@ -899,12 +900,21 @@ static int sx9310_set_indio_dev_name(struct device *dev,
> return 0;
> }
>
> +static void sx9310_regulator_disable(void *supplies)
> +{
> + regulator_bulk_disable(2, supplies);
> +}
> +
> static int sx9310_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> int ret;
> struct iio_dev *indio_dev;
> struct sx9310_data *data;
> + struct regulator_bulk_data supplies[] = {
> + { .supply = "vdd" },
> + { .supply = "svdd" },
> + };
>
> indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> if (indio_dev == NULL)
> @@ -919,6 +929,23 @@ static int sx9310_probe(struct i2c_client *client,
> if (IS_ERR(data->regmap))
> return PTR_ERR(data->regmap);
>
> + ret = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(supplies), supplies);
> + if (ret)
> + return ret;
> +
> + ret = regulator_bulk_enable(ARRAY_SIZE(supplies), supplies);
> + if (ret)
> + return ret;
> + /* Must wait for Tpor time after initial power up */
> + usleep_range(1000, 1100);
> +
> + /* Update sx9310_regulator_disable() size if this bug is hit */
> + BUILD_BUG_ON(ARRAY_SIZE(supplies) != 2);
> + ret = devm_add_action_or_reset(&client->dev, sx9310_regulator_disable,
> + supplies);

...but, but... Aren't you storing a pointer to stack memory? How
does that work? I think you either need to store the "struct
regulator_bulk_data" in your private data or just make two normal
regulator calls.

-Doug