regulator: core: Add support for active-discharge configuration

Add support to enable/disable active discharge of regulator via
machine constraints. This configuration is done when setting
machine constraint during regulator register and if regulator
driver implemented the callback ops.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 16ac9e1..59dbaf7 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -93,6 +93,8 @@
  * @get_current_limit: Get the configured limit for a current-limited regulator.
  * @set_input_current_limit: Configure an input limit.
  *
+ * @set_active_discharge: Set active discharge enable/disable of regulators.
+ *
  * @set_mode: Set the configured operating mode for the regulator.
  * @get_mode: Get the configured operating mode for the regulator.
  * @get_status: Return actual (not as-configured) status of regulator, as a
@@ -149,6 +151,7 @@
 
 	int (*set_input_current_limit) (struct regulator_dev *, int lim_uA);
 	int (*set_over_current_protection) (struct regulator_dev *);
+	int (*set_active_discharge) (struct regulator_dev *, bool enable);
 
 	/* enable/disable regulator */
 	int (*enable) (struct regulator_dev *);
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index a1067d0..5d627c8 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -42,6 +42,13 @@
 #define REGULATOR_CHANGE_DRMS		0x10
 #define REGULATOR_CHANGE_BYPASS		0x20
 
+/* Regulator active discharge flags */
+enum regulator_active_discharge {
+	REGULATOR_ACTIVE_DISCHARGE_DEFAULT,
+	REGULATOR_ACTIVE_DISCHARGE_DISABLE,
+	REGULATOR_ACTIVE_DISCHARGE_ENABLE,
+};
+
 /**
  * struct regulator_state - regulator state during low power system states
  *
@@ -100,6 +107,9 @@
  * @initial_state: Suspend state to set by default.
  * @initial_mode: Mode to set at startup.
  * @ramp_delay: Time to settle down after voltage change (unit: uV/us)
+ * @active_discharge: Enable/disable active discharge. The enum
+ *		      regulator_active_discharge values are used for
+ *		      initialisation.
  * @enable_time: Turn-on time of the rails (unit: microseconds)
  */
 struct regulation_constraints {
@@ -140,6 +150,8 @@
 	unsigned int ramp_delay;
 	unsigned int enable_time;
 
+	unsigned int active_discharge;
+
 	/* constraint flags */
 	unsigned always_on:1;	/* regulator never off when system is on */
 	unsigned boot_on:1;	/* bootloader/firmware enabled regulator */