[PATCH/RFC v4 1/4] regulator: core: add prepare and resume_early

Yoshihiro Shimoda
2020-06-26T09:32:33Z

The regulator-fixed driver is possible to be off by firmware
like PSCI while the system is suspended. If a consumer could get
such a condition from regulator_is_enabled(), it's useful by
consumers.

The regulator subsystem already has regulator-state-(standby|mem|disk)
sub-nodes and regulator-off-in-suspend property. However,
suitable regulator_ops APIs didn't exist.

So, add new regulator_ops APIs and prepare()/resume_early() in
the regulator_pm_ops to set/clear the condition by new APIs before
suspend() functions of consumers are called.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
drivers/regulator/core.c | 42 ++++++++++++++++++++++++++++++++++++++++
include/linux/regulator/driver.h | 6 ++++++
2 files changed, 48 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 03154f5..93eb2a3 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5286,6 +5286,46 @@ void regulator_unregister(struct regulator_dev *rdev)
EXPORT_SYMBOL_GPL(regulator_unregister);

#ifdef CONFIG_SUSPEND
+static int regulator_prepare(struct device *dev)
+{
+ struct regulator_dev *rdev = dev_to_rdev(dev);
+ suspend_state_t state = pm_suspend_target_state;
+ struct regulator_state *rstate;
+ int ret = 0;
+
+ rstate = regulator_get_suspend_state(rdev, state);
+ if (rstate == NULL)
+ return 0;
+
+ regulator_lock(rdev);
+ if (rstate->enabled == DISABLE_IN_SUSPEND &&
+ rdev->desc->ops->set_prepare_disable)
+ ret = rdev->desc->ops->set_prepare_disable(rdev);
+ regulator_unlock(rdev);
+
+ return ret;
+}
+
+static int regulator_resume_early(struct device *dev)
+{
+ struct regulator_dev *rdev = dev_to_rdev(dev);
+ suspend_state_t state = pm_suspend_target_state;
+ struct regulator_state *rstate;
+ int ret = 0;
+
+ rstate = regulator_get_suspend_state(rdev, state);
+ if (rstate == NULL)
+ return 0;
+
+ regulator_lock(rdev);
+ if (rstate->enabled == DISABLE_IN_SUSPEND &&
+ rdev->desc->ops->clear_resume_early_disable)
+ ret = rdev->desc->ops->clear_resume_early_disable(rdev);
+ regulator_unlock(rdev);
+
+ return ret;
+}
+
/**
* regulator_suspend - prepare regulators for system wide suspend
* @dev: ``&struct device`` pointer that is passed to _regulator_suspend()
@@ -5336,6 +5376,8 @@ static int regulator_resume(struct device *dev)

#ifdef CONFIG_PM
static const struct dev_pm_ops __maybe_unused regulator_pm_ops = {
+ .prepare = regulator_prepare,
+ .resume_early = regulator_resume_early,
.suspend = regulator_suspend,
.resume = regulator_resume,
};
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 7eb9fea..299a504 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -115,6 +115,10 @@ enum regulator_status {
* suspended.
* @set_suspend_disable: Mark the regulator as disabled when the system is
* suspended.
+ * @set_prepare_disable: Mark the regulator as disabled when the system is
+ * suspending.
+ * @clear_resume_early_disable: Unmark the regulator as disabled when
+ * the system is resuming.
* @set_suspend_mode: Set the operating mode for the regulator when the
* system is suspended.
*
@@ -195,6 +199,8 @@ struct regulator_ops {
/* enable/disable regulator in suspend state */
int (*set_suspend_enable) (struct regulator_dev *);
int (*set_suspend_disable) (struct regulator_dev *);
+ int (*set_prepare_disable) (struct regulator_dev *);
+ int (*clear_resume_early_disable) (struct regulator_dev *);

/* set regulator suspend operating mode (defined in consumer.h) */
int (*set_suspend_mode) (struct regulator_dev *, unsigned int mode);
--
2.7.4