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>

drivers/regulator/core.c

@@ -1151,6 +1151,17 @@ static int set_machine_constraints(struct regulator_dev *rdev,
 		}
 	}
 
+	if (rdev->constraints->active_discharge && ops->set_active_discharge) {
+		bool ad_state = (rdev->constraints->active_discharge ==
+			      REGULATOR_ACTIVE_DISCHARGE_ENABLE) ? true : false;
+
+		ret = ops->set_active_discharge(rdev, ad_state);
+		if (ret < 0) {
+			rdev_err(rdev, "failed to set active discharge\n");
+			return ret;
+		}
+	}
+
 	print_constraints(rdev);
 	return 0;
 out: