drm/rockchip: analogix_dp: add supports for regulators in edp IP

I found if eDP_AVDD_1V0 and eDP_AVDD_1V8 are not been power at
RK3288, once trying to enable the pclk clock, the kernel would dead.
This patch would try to enable them first.

The eDP_AVDD_1V8 is used for eDP phy, and the eDP_AVDD_1V0 are used
both for eDP phy and controller.

Change-Id: I4e8a34609d5b292d7da77385ff15bebbf258090c
Signed-off-by: Randy Li <ayaka@soulik.info>
Signed-off-by: Randy Li <randy.li@rock-chips.com>

Documentation/devicetree/bindings/display/rockchip/analogix_dp-rockchip.txt

@@ -29,6 +29,10 @@ Required properties:
     Port 0: contained 2 endpoints, connecting to the output of vop.
     Port 1: contained 1 endpoint, connecting to the input of panel.
 
+Optional properties
+- vcc-supply: Regulator for eDP_AVDD_1V0.
+- vccio-supply: Regulator for eDP_AVDD_1V8.
+
 For the below properties, please refer to Analogix DP binding document:
  * Documentation/devicetree/bindings/drm/bridge/analogix_dp.txt
 - phys (required)

drivers/gpu/drm/rockchip/analogix_dp-rockchip.c

@@ -17,6 +17,7 @@
 #include <linux/of_device.h>
 #include <linux/of_graph.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 #include <linux/clk.h>
 
@@ -59,6 +60,8 @@ struct rockchip_dp_device {
 	struct clk               *pclk;
 	struct regmap            *grf;
 	struct reset_control     *rst;
+	struct regulator         *vcc_supply;
+	struct regulator         *vccio_supply;
 
 	const struct rockchip_dp_chip_data *data;
 
@@ -79,6 +82,24 @@ static int rockchip_dp_poweron(struct analogix_dp_plat_data *plat_data)
 	struct rockchip_dp_device *dp = to_dp(plat_data);
 	int ret;
 
+	if (!IS_ERR(dp->vcc_supply)) {
+		ret = regulator_enable(dp->vcc_supply);
+		if (ret) {
+			dev_err(dp->dev,
+				"failed to enable vcc regulator: %d\n", ret);
+			return ret;
+		}
+	}
+
+	if (!IS_ERR(dp->vccio_supply)) {
+		ret = regulator_enable(dp->vccio_supply);
+		if (ret) {
+			dev_err(dp->dev,
+				"failed to enable vccio regulator: %d\n", ret);
+			return ret;
+		}
+	}
+
 	ret = clk_prepare_enable(dp->pclk);
 	if (ret < 0) {
 		dev_err(dp->dev, "failed to enable pclk %d\n", ret);
@@ -100,6 +121,11 @@ static int rockchip_dp_powerdown(struct analogix_dp_plat_data *plat_data)
 
 	clk_disable_unprepare(dp->pclk);
 
+	if (!IS_ERR(dp->vccio_supply))
+		regulator_disable(dp->vccio_supply);
+	if (!IS_ERR(dp->vcc_supply))
+		regulator_disable(dp->vcc_supply);
+
 	return 0;
 }
 
@@ -232,6 +258,32 @@ static int rockchip_dp_init(struct rockchip_dp_device *dp)
 		return PTR_ERR(dp->rst);
 	}
 
+	dp->vcc_supply = devm_regulator_get_optional(dev, "vcc");
+	dp->vccio_supply = devm_regulator_get_optional(dev, "vccio");
+
+	if (IS_ERR(dp->vcc_supply)) {
+		dev_err(dev, "failed to get vcc regulator: %ld\n",
+			PTR_ERR(dp->vcc_supply));
+	} else {
+		ret = regulator_enable(dp->vcc_supply);
+		if (ret) {
+			dev_err(dev,
+				"failed to enable vcc regulator: %d\n", ret);
+			return ret;
+		}
+	}
+	if (IS_ERR(dp->vccio_supply)) {
+		dev_err(dev, "failed to get vccio regulator: %ld\n",
+			PTR_ERR(dp->vccio_supply));
+	} else {
+		ret = regulator_enable(dp->vccio_supply);
+		if (ret) {
+			dev_err(dev,
+				"failed to enable vccio regulator: %d\n", ret);
+			return ret;
+		}
+	}
+
 	ret = clk_prepare_enable(dp->pclk);
 	if (ret < 0) {
 		dev_err(dp->dev, "failed to enable pclk %d\n", ret);