[PATCH 2/2] regulator: core: Provide per-regulator runtime PM support

[Mark Brown <broonie@kernel.org>]

Provide a flag auto_runtime_pm in the regulator_desc which causes the
regulator core to take a runtime PM reference to a regulator while it
is enabled. This helps integration with chip wide power management for
auxiliary PMICs, they may be able to implement chip wide power savings
if nothing on the PMIC is in use.

Signed-off-by: Mark Brown <broonie@kernel.org>
---

Not tested at all yet, pushing out for testing by others who have
devices that could benefit from this.

 drivers/regulator/core.c         | 20 ++++++++++++++++++--
 include/linux/regulator/driver.h |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 3308c6bb83db..968ff3081e6c 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -26,6 +26,7 @@
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/of.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/consumer.h>
@@ -2059,17 +2060,23 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 		}
 	}
 
+	if (rdev->desc->auto_runtime_pm) {
+		ret = pm_runtime_get_sync(rdev->dev.parent);
+		if (ret < 0)
+			goto err;
+	}
+
 	if (rdev->ena_pin) {
 		if (!rdev->ena_gpio_state) {
 			ret = regulator_ena_gpio_ctrl(rdev, true);
 			if (ret < 0)
-				return ret;
+				goto err_pm;
 			rdev->ena_gpio_state = 1;
 		}
 	} else if (rdev->desc->ops->enable) {
 		ret = rdev->desc->ops->enable(rdev);
 		if (ret < 0)
-			return ret;
+			goto err_pm;
 	} else {
 		return -EINVAL;
 	}
@@ -2084,6 +2091,12 @@ static int _regulator_do_enable(struct regulator_dev *rdev)
 	trace_regulator_enable_complete(rdev_get_name(rdev));
 
 	return 0;
+
+err_pm:
+	if (rdev->desc->auto_runtime_pm)
+		pm_runtime_put_autosuspend(rdev->dev.parent);
+err:
+	return ret;
 }
 
 /* locks held by regulator_enable() */
@@ -2177,6 +2190,9 @@ static int _regulator_do_disable(struct regulator_dev *rdev)
 			return ret;
 	}
 
+	if (rdev->desc->auto_runtime_pm)
+		pm_runtime_put_autosuspend(rdev->dev.parent);
+
 	/* cares about last_off_jiffy only if off_on_delay is required by
 	 * device.
 	 */
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 3ac0f306f033..dccea032a143 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -282,6 +282,7 @@ struct regulator_desc {
 			    struct regulator_config *);
 	int id;
 	unsigned int continuous_voltage_range:1;
+	unsigned int auto_runtime_pm:1;
 	unsigned n_voltages;
 	const struct regulator_ops *ops;
 	int irq;
-- 
2.7.0.rc3