On Tue 02 Jun 03:09 PDT 2020, Sumit Semwal wrote:
> Some regulators might need to verify that they have indeed been enabled
> after the enable() call is made and enable_time delay has passed.
>
> This is implemented by repeatedly checking is_enabled() upto
> poll_enabled_time, waiting for the already calculated enable delay in
> each iteration.
>
> Signed-off-by: Sumit Semwal
> --
> v2: Address review comments, including swapping enable_time and
> poll_enabled_time.
> ---
> drivers/regulator/core.c | 58 +++-
> include/linux/regulator/driver.h | 5 +++
> 2 files changed, 62 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index 7486f6e4e613..d9ab888da95f 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -2347,6 +2347,32 @@ static void _regulator_enable_delay(unsigned int delay)
> udelay(us);
> }
>
> +/* _regulator_check_status_enabled
Please make all your kerneldoc follow:
https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation
> + *
> + * returns:
> + * 1 if status shows regulator is in enabled state
> + * 0 if not enabled state
> + * else, error value as received from ops->get_status()
> + */
> +static inline int _regulator_check_status_enabled(struct regulator_dev *rdev)
> +{
> + int ret = rdev->desc->ops->get_status(rdev);
> +
> + if (ret < 0) {
> + rdev_info(rdev, "get_status returned error: %d\n", ret);
> + return ret;
> + }
> +
> + switch (ret) {
> + case REGULATOR_STATUS_OFF:
> + case REGULATOR_STATUS_ERROR:
> + case REGULATOR_STATUS_UNDEFINED:
> + return 0;
> + default:
> + return 1;
> + }
> +}
> +
> static int _regulator_do_enable(struct regulator_dev *rdev)
> {
> int ret, delay;
> @@ -2407,7 +2433,37 @@ static int _regulator_do_enable(struct regulator_dev
> *rdev)
>* together. */
> trace_regulator_enable_delay(rdev_get_name(rdev));
>
> - _regulator_enable_delay(delay);
> + /* If poll_enabled_time is set, poll upto the delay calculated
> + * above, delaying poll_enabled_time uS to check if the regulator
> + * actually got enabled.
> + * If the regulator isn't enabled after enable_delay has
> + * expired, return -ETIMEDOUT.
> + */
> + if (rdev->desc->poll_enabled_time) {
> + unsigned int time_remaining = delay;
> +
> + while (time_remaining > 0) {
> + _regulator_enable_delay(rdev->desc->poll_enabled_time);
> +
> + if (rdev->desc->ops->get_status) {
> + ret = _regulator_check_status_enabled(rdev);
> + if (ret < 0)
> + return ret;
> + else if (ret)
> + break;
> + } else if (rdev->desc->ops->is_enabled(rdev))
> + break;
> +
> + time_remaining -= rdev->desc->poll_enabled_time;
> + }
> +
> + if (time_remaining <= 0) {
> + rdev_err(rdev, "Enabled check failed.\n");
> + return -ETIMEDOUT;
> + }
> + } else {
> + _regulator_enable_delay(delay);
> + }
>
> trace_regulator_enable_complete(rdev_get_name(rdev));
>
> diff --git a/include/linux/regulator/driver.h
> b/include/linux/regulator/driver.h
> index 29d920516e0b..bb50e943010f 100644
> --- a/include/linux/regulator/driver.h
> +++ b/include/linux/regulator/driver.h
> @@ -322,6 +322,9 @@ enum regulator_type {
> * @enable_time: Time taken for initial enable of regulator (in uS).
> * @off_on_delay: guard time (in uS), before re-enabling a regulator
> *
> + * @poll_enabled_time: Maximum time (in uS) to poll if the regulator is
> + * actually enabled, after enable() call
I read this as "how long should we stay in the poll loop". I think it
would be better describes as something like "The polling interval to use
while checking that the regulator was actually enabled".
Regards,
Bjorn
> + *
> * @of_map_mode: Maps a hardware mode defined in a DeviceTree to a standard
> mode
> */
> struct regulator_desc {
> @@ -389,6 +392,8 @@ struct regulator_desc {
>
> unsigned int off_on_delay;
>
> + unsigned int poll_enabled_time;
> +
> unsigned int (*of_map_mode)(unsigned int mode);
> };
>
> --
> 2.26.2
>
