[PATCH 02/12] drm: sun4i: Add support for enabling DDC I2C bus to dw_hdmi glue

[megous@xxxxxxxxxx]

From: Ondrej Jirman <megous@xxxxxxxxxx>

Orange Pi 3 board requires enabling DDC I2C bus via some GPIO connected
transistors, before it can be used. Model this as a power supply for DDC
(via regulator framework).

Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
---
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 17 ++++++++++++++++-
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h |  1 +
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index dc47720c99ba..a1518525fa2f 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -146,16 +146,28 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
 		return PTR_ERR(hdmi->regulator);
 	}
 
+	hdmi->ddc_regulator = devm_regulator_get(dev, "ddc");
+	if (IS_ERR(hdmi->ddc_regulator)) {
+		dev_err(dev, "Couldn't get ddc regulator\n");
+		return PTR_ERR(hdmi->ddc_regulator);
+	}
+
 	ret = regulator_enable(hdmi->regulator);
 	if (ret) {
 		dev_err(dev, "Failed to enable regulator\n");
 		return ret;
 	}
 
+	ret = regulator_enable(hdmi->ddc_regulator);
+	if (ret) {
+		dev_err(dev, "Failed to enable ddc regulator\n");
+		goto err_disable_regulator;
+	}
+
 	ret = reset_control_deassert(hdmi->rst_ctrl);
 	if (ret) {
 		dev_err(dev, "Could not deassert ctrl reset control\n");
-		goto err_disable_regulator;
+		goto err_disable_ddc_regulator;
 	}
 
 	ret = clk_prepare_enable(hdmi->clk_tmds);
@@ -208,6 +220,8 @@ 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_ddc_regulator:
+	regulator_disable(hdmi->ddc_regulator);
 err_disable_regulator:
 	regulator_disable(hdmi->regulator);
 
@@ -223,6 +237,7 @@ 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->ddc_regulator);
 	regulator_disable(hdmi->regulator);
 }
 
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
index 720c5aa8adc1..6e93d55560b6 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -188,6 +188,7 @@ struct sun8i_dw_hdmi {
 	struct sun8i_hdmi_phy		*phy;
 	struct dw_hdmi_plat_data	plat_data;
 	struct regulator		*regulator;
+	struct regulator		*ddc_regulator;
 	const struct sun8i_dw_hdmi_quirks *quirks;
 	struct reset_control		*rst_ctrl;
 };
-- 
2.21.0