Unverified Commit f7d7ad42 authored by Sumit Semwal's avatar Sumit Semwal Committed by Mark Brown
Browse files

regulator: Allow regulators to verify enabled during enable() 



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: default avatarSumit Semwal <sumit.semwal@linaro.org>
Link: https://lore.kernel.org/r/20200622124110.20971-2-sumit.semwal@linaro.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 308e65ad

drivers/regulator/core.c

+62 −1
Original line number Diff line number Diff line
@@ -2347,6 +2347,37 @@ static void _regulator_enable_delay(unsigned int delay) 
		udelay(us);

}



/**

 * _regulator_check_status_enabled

 *

 * A helper function to check if the regulator status can be interpreted

 * as 'regulator is enabled'.

 * @rdev: the regulator device to check

 *

 * Return:

 * * 1			- if status shows regulator is in enabled state

 * * 0			- if not enabled state

 * * 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 +2438,37 @@ static int _regulator_do_enable(struct regulator_dev *rdev) 
	 * together.  */

	trace_regulator_enable_delay(rdev_get_name(rdev));



	/* 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 timed out\n");

			return -ETIMEDOUT;

		}

	} else {

		_regulator_enable_delay(delay);

	}



	trace_regulator_enable_complete(rdev_get_name(rdev));

include/linux/regulator/driver.h

+5 −0
Original line number Diff line number Diff line
@@ -305,6 +305,9 @@ 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: The polling interval (in uS) to use while checking that

 *                     the regulator was actually enabled. Max upto enable_time.

 *

 * @of_map_mode: Maps a hardware mode defined in a DeviceTree to a standard mode

 */

struct regulator_desc {
@@ -372,6 +375,8 @@ struct regulator_desc { 


	unsigned int off_on_delay;



	unsigned int poll_enabled_time;



	unsigned int (*of_map_mode)(unsigned int mode);

};

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