[PATCH v4 10/11] drm/sun4i: Add support for HDMI voltage regulator

[Icenowy Zheng]

From: Jernej Skrabec <jernej.skrabec at siol.net>

Some boards have HDMI VCC pin connected to voltage regulator which may
not be turned on by default.

Add support for such boards by adding voltage regulator handling code to
HDMI driver.

Signed-off-by: Jernej Skrabec <jernej.skrabec at siol.net>
[Icenowy: change supply name to "hvcc"]
Signed-off-by: Icenowy Zheng <icenowy at aosc.io>
---
Changes in v4:
- Rename the supply name to "hvcc".
Changes in v3.1:
- New patch. (Replaced "drm: sun4i: add support for HVCC regulator
  for DWC HDMI glue" by Icenowy.)

 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 17 ++++++++++++++++-
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h |  2 ++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 31875b636434..ed2983770e9c 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -125,10 +125,22 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
 		return PTR_ERR(hdmi->clk_tmds);
 	}
 
+	hdmi->regulator = devm_regulator_get(dev, "hvcc");
+	if (IS_ERR(hdmi->regulator)) {
+		dev_err(dev, "Couldn't get regulator\n");
+		return PTR_ERR(hdmi->regulator);
+	}
+
+	ret = regulator_enable(hdmi->regulator);
+	if (ret) {
+		dev_err(dev, "Failed to enable regulator\n");
+		return ret;
+	}
+
 	ret = reset_control_deassert(hdmi->rst_ctrl);
 	if (ret) {
 		dev_err(dev, "Could not deassert ctrl reset control\n");
-		return ret;
+		goto err_disable_regulator;
 	}
 
 	ret = clk_prepare_enable(hdmi->clk_tmds);
@@ -183,6 +195,8 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
 	clk_disable_unprepare(hdmi->clk_tmds);
 err_assert_ctrl_reset:
 	reset_control_assert(hdmi->rst_ctrl);
+err_disable_regulator:
+	regulator_disable(hdmi->regulator);
 
 	return ret;
 }
@@ -196,6 +210,7 @@ static void sun8i_dw_hdmi_unbind(struct device *dev, struct device *master,
 	sun8i_hdmi_phy_remove(hdmi);
 	clk_disable_unprepare(hdmi->clk_tmds);
 	reset_control_assert(hdmi->rst_ctrl);
+	regulator_disable(hdmi->regulator);
 }
 
 static const struct component_ops sun8i_dw_hdmi_ops = {
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
index aadbe0a10b0c..7fdc1ecd2892 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -10,6 +10,7 @@
 #include <drm/drm_encoder.h>
 #include <linux/clk.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/reset.h>
 
 #define SUN8I_HDMI_PHY_DBG_CTRL_REG	0x0000
@@ -176,6 +177,7 @@ struct sun8i_dw_hdmi {
 	struct drm_encoder		encoder;
 	struct sun8i_hdmi_phy		*phy;
 	struct dw_hdmi_plat_data	plat_data;
+	struct regulator		*regulator;
 	struct reset_control		*rst_ctrl;
 };
 
-- 
2.18.0