[PATCH 5/7] regulator: core: Lock dependent regulators

From: Maciej Purski
Date: Mon Jun 04 2018 - 10:01:38 EST


Implementing coupled regulators adds a new dependency between
regulators. Therefore, the current locking model should be changed.
Coupled regulators should be locked with regulator's supplies at the
same time.

Add new function regulator_lock_dependent(), which locks all regulators
related with the one, that is being changed.

Signed-off-by: Maciej Purski <m.purski@xxxxxxxxxxx>
---
drivers/regulator/core.c | 75 +++++++++++++++++++++++++++++++++---------------
1 file changed, 52 insertions(+), 23 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 0b366c5..7c57268 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -201,38 +201,67 @@ 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
- * @rdev: regulator source
+ * 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
* @supply: regulator supply name
@@ -3332,12 +3361,12 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
int ret = 0;

pr_err("%s: %d\n", __func__, __LINE__);
- 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;
}
@@ -3415,12 +3444,12 @@ 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;
}
@@ -3612,11 +3641,11 @@ 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;
}
--
2.7.4