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Unverified Commit 456e7cdf authored by Maciej Purski's avatar Maciej Purski Committed by Mark Brown
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regulator: core: Change voltage setting path 



On Odroid XU3/4 and other Exynos5422 based boards there is a case, that
different devices on the board are supplied by different regulators
with non-fixed voltages. If one of these devices temporarily requires
higher voltage, there might occur a situation that the spread between
two devices' voltages is so high, that there is a risk of changing
'high' and 'low' states on the interconnection between devices powered
by those regulators.

Uncoupled regulators should be a special case of coupled regulators, so
they should share a common voltage setting path. When enabling,
disabling or setting voltage of a coupled regulator, all coupled
regulators should be locked. Regulator's supplies should be locked, when
setting voltage of a single regulator. Enabling a coupled regulator or
setting its voltage should not be possible if some of its coupled
regulators, has not been registered.

Add function for locking coupled regulators and supplies. Extract
a new function regulator_set_voltage_rdev() from
regulator_set_voltage_unlocked(), which is called when setting
voltage of a single regulator.

Signed-off-by: default avatarMaciej Purski <m.purski@samsung.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 69686176

drivers/regulator/core.c

+107 −52
Original line number Diff line number Diff line
@@ -107,6 +107,9 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev, 
				     int min_uV, int max_uV);

static int regulator_balance_voltage(struct regulator_dev *rdev,

				     suspend_state_t state);

static int regulator_set_voltage_rdev(struct regulator_dev *rdev,

				      int min_uV, int max_uV,

				      suspend_state_t state);

static struct regulator *create_regulator(struct regulator_dev *rdev,

					  struct device *dev,

					  const char *supply_name);
@@ -198,37 +201,66 @@ static void regulator_unlock(struct regulator_dev *rdev) 
	}

}



/**

 * regulator_lock_supply - lock a regulator and its supplies

 * @rdev:         regulator source

 */

static void regulator_lock_supply(struct regulator_dev *rdev)

static int regulator_lock_recursive(struct regulator_dev *rdev,

				    unsigned int subclass)

{

	struct regulator_dev *c_rdev;

	int i;



	for (i = 0; rdev; rdev = rdev_get_supply(rdev), i++)

		regulator_lock_nested(rdev, i);

	for (i = 0; i < rdev->coupling_desc.n_coupled; i++) {

		c_rdev = rdev->coupling_desc.coupled_rdevs[i];



		if (!c_rdev)

			continue;



		regulator_lock_nested(c_rdev, subclass++);



		if (c_rdev->supply)

			subclass =

				regulator_lock_recursive(c_rdev->supply->rdev,

							 subclass);

	}



	return subclass;

}



/**

 * regulator_unlock_supply - unlock a regulator and its supplies

 * regulator_unlock_dependent - unlock regulator's suppliers and coupled

 *				regulators

 * @rdev:			regulator source

 *

 * Unlock all regulators related with rdev by coupling or suppling.

 */

static void regulator_unlock_supply(struct regulator_dev *rdev)

static void regulator_unlock_dependent(struct regulator_dev *rdev)

{

	struct regulator *supply;

	struct regulator_dev *c_rdev;

	int i;



	while (1) {

		regulator_unlock(rdev);

		supply = rdev->supply;

	for (i = 0; i < rdev->coupling_desc.n_coupled; i++) {

		c_rdev = rdev->coupling_desc.coupled_rdevs[i];



		if (!rdev->supply)

			return;

		if (!c_rdev)

			continue;



		regulator_unlock(c_rdev);



		rdev = supply->rdev;

		if (c_rdev->supply)

			regulator_unlock_dependent(c_rdev->supply->rdev);

	}

}



/**

 * regulator_lock_dependent - lock regulator's suppliers and coupled regulators

 * @rdev:			regulator source

 *

 * This function as a wrapper on regulator_lock_recursive(), which locks

 * all regulators related with rdev by coupling or suppling.

 */

static inline void regulator_lock_dependent(struct regulator_dev *rdev)

{

	regulator_lock_recursive(rdev, 0);

}



/**

 * of_get_regulator - get a regulator device node based on supply name

 * @dev: Device pointer for the consumer (of regulator) device
@@ -2261,6 +2293,11 @@ int regulator_enable(struct regulator *regulator) 
	struct regulator_dev *rdev = regulator->rdev;

	int ret = 0;



	if (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled) {

		rdev_err(rdev, "not all coupled regulators registered\n");

		return -EPERM;

	}



	if (regulator->always_on)

		return 0;
@@ -2270,9 +2307,12 @@ int regulator_enable(struct regulator *regulator) 
			return ret;

	}



	mutex_lock(&rdev->mutex);

	regulator_lock_dependent(rdev);

	ret = _regulator_enable(rdev);

	mutex_unlock(&rdev->mutex);

	/* balance only if there are regulators coupled */

	if (rdev->coupling_desc.n_coupled > 1)

		regulator_balance_voltage(rdev, PM_SUSPEND_ON);

	regulator_unlock_dependent(rdev);



	if (ret != 0 && rdev->supply)

		regulator_disable(rdev->supply);
@@ -2378,9 +2418,11 @@ int regulator_disable(struct regulator *regulator) 
	if (regulator->always_on)

		return 0;



	mutex_lock(&rdev->mutex);

	regulator_lock_dependent(rdev);

	ret = _regulator_disable(rdev);

	mutex_unlock(&rdev->mutex);

	if (rdev->coupling_desc.n_coupled > 1)

		regulator_balance_voltage(rdev, PM_SUSPEND_ON);

	regulator_unlock_dependent(rdev);



	if (ret == 0 && rdev->supply)

		regulator_disable(rdev->supply);
@@ -2429,10 +2471,12 @@ int regulator_force_disable(struct regulator *regulator) 
	struct regulator_dev *rdev = regulator->rdev;

	int ret;



	mutex_lock(&rdev->mutex);

	regulator_lock_dependent(rdev);

	regulator->uA_load = 0;

	ret = _regulator_force_disable(regulator->rdev);

	mutex_unlock(&rdev->mutex);

	if (rdev->coupling_desc.n_coupled > 1)

		regulator_balance_voltage(rdev, PM_SUSPEND_ON);

	regulator_unlock_dependent(rdev);



	if (rdev->supply)

		while (rdev->open_count--)
@@ -2580,9 +2624,9 @@ int regulator_is_enabled(struct regulator *regulator) 
	if (regulator->always_on)

		return 1;



	mutex_lock(&regulator->rdev->mutex);

	regulator_lock_dependent(regulator->rdev);

	ret = _regulator_is_enabled(regulator->rdev);

	mutex_unlock(&regulator->rdev->mutex);

	regulator_unlock_dependent(regulator->rdev);



	return ret;

}
@@ -2991,8 +3035,12 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
	int ret = 0;

	int old_min_uV, old_max_uV;

	int current_uV;

	int best_supply_uV = 0;

	int supply_change_uV = 0;



	if (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled) {

		rdev_err(rdev, "not all coupled regulators registered\n");

		ret = -EPERM;

		goto out;

	}



	/* If we're setting the same range as last time the change

	 * should be a noop (some cpufreq implementations use the same
@@ -3036,6 +3084,27 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
	if (ret < 0)

		goto out2;



	/* for not coupled regulators this will just set the voltage */

	ret = regulator_balance_voltage(rdev, state);

	if (ret < 0)

		goto out2;



out:

	return 0;

out2:

	voltage->min_uV = old_min_uV;

	voltage->max_uV = old_max_uV;



	return ret;

}



static int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV,

				      int max_uV, suspend_state_t state)

{

	int best_supply_uV = 0;

	int supply_change_uV = 0;

	int ret;



	if (rdev->supply &&

	    regulator_ops_is_valid(rdev->supply->rdev,

				   REGULATOR_CHANGE_VOLTAGE) &&
@@ -3047,13 +3116,13 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
		selector = regulator_map_voltage(rdev, min_uV, max_uV);

		if (selector < 0) {

			ret = selector;

			goto out2;

			goto out;

		}



		best_supply_uV = _regulator_list_voltage(rdev, selector, 0);

		if (best_supply_uV < 0) {

			ret = best_supply_uV;

			goto out2;

			goto out;

		}



		best_supply_uV += rdev->desc->min_dropout_uV;
@@ -3061,7 +3130,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
		current_supply_uV = _regulator_get_voltage(rdev->supply->rdev);

		if (current_supply_uV < 0) {

			ret = current_supply_uV;

			goto out2;

			goto out;

		}



		supply_change_uV = best_supply_uV - current_supply_uV;
@@ -3073,7 +3142,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
		if (ret) {

			dev_err(&rdev->dev, "Failed to increase supply voltage: %d\n",

					ret);

			goto out2;

			goto out;

		}

	}
@@ -3083,7 +3152,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
		ret = _regulator_do_set_suspend_voltage(rdev, min_uV,

							max_uV, state);

	if (ret < 0)

		goto out2;

		goto out;



	if (supply_change_uV < 0) {

		ret = regulator_set_voltage_unlocked(rdev->supply,
@@ -3096,11 +3165,6 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator, 
	}



out:

	return ret;

out2:

	voltage->min_uV = old_min_uV;

	voltage->max_uV = old_max_uV;



	return ret;

}
@@ -3274,17 +3338,8 @@ static int regulator_balance_voltage(struct regulator_dev *rdev, 
			goto out;

		}



		/*

		 * Lock just the supply regulators, as the regulator itself

		 * is already locked by regulator_lock_coupled().

		 */

		if (best_rdev->supply)

			regulator_lock_supply(best_rdev->supply->rdev);



		ret = regulator_set_voltage_rdev(best_rdev, best_uV,

						 best_uV, state);

		if (best_rdev->supply)

			regulator_unlock_supply(best_rdev->supply->rdev);



		if (ret < 0)

			goto out;
@@ -3316,12 +3371,12 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV) 
{

	int ret = 0;



	regulator_lock_supply(regulator->rdev);

	regulator_lock_dependent(regulator->rdev);



	ret = regulator_set_voltage_unlocked(regulator, min_uV, max_uV,

					     PM_SUSPEND_ON);



	regulator_unlock_supply(regulator->rdev);

	regulator_unlock_dependent(regulator->rdev);



	return ret;

}
@@ -3399,12 +3454,12 @@ int regulator_set_suspend_voltage(struct regulator *regulator, int min_uV, 
	if (regulator_check_states(state) || state == PM_SUSPEND_ON)

		return -EINVAL;



	regulator_lock_supply(regulator->rdev);

	regulator_lock_dependent(regulator->rdev);



	ret = _regulator_set_suspend_voltage(regulator, min_uV,

					     max_uV, state);



	regulator_unlock_supply(regulator->rdev);

	regulator_unlock_dependent(regulator->rdev);



	return ret;

}
@@ -3596,11 +3651,11 @@ int regulator_get_voltage(struct regulator *regulator) 
{

	int ret;



	regulator_lock_supply(regulator->rdev);

	regulator_lock_dependent(regulator->rdev);



	ret = _regulator_get_voltage(regulator->rdev);



	regulator_unlock_supply(regulator->rdev);

	regulator_unlock_dependent(regulator->rdev);



	return ret;

}