drm: sun4i: Add support for enabling DDC I2C bus to sun8i_dw_hdmi glue

Orange Pi 3 board requires enabling a voltage shifting circuit via GPIO
for the DDC bus to be usable.

Add support for hdmi-connector node's optional ddc-en-gpios property to
support this use case.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806155744.10263-4-megous@megous.com

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 8ca5af0c912f920592b64f245e8418445334a0f8..a44dca4b0219e0413d97762d90e9d262fc1049ff 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -97,10 +97,34 @@ crtcs_exit:
        return crtcs;
 }
 
+static int sun8i_dw_hdmi_find_connector_pdev(struct device *dev,
+                                            struct platform_device **pdev_out)
+{
+       struct platform_device *pdev;
+       struct device_node *remote;
+
+       remote = of_graph_get_remote_node(dev->of_node, 1, -1);
+       if (!remote)
+               return -ENODEV;
+
+       if (!of_device_is_compatible(remote, "hdmi-connector")) {
+               of_node_put(remote);
+               return -ENODEV;
+       }
+
+       pdev = of_find_device_by_node(remote);
+       of_node_put(remote);
+       if (!pdev)
+               return -ENODEV;
+
+       *pdev_out = pdev;
+       return 0;
+}
+
 static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
                              void *data)
 {
-       struct platform_device *pdev = to_platform_device(dev);
+       struct platform_device *pdev = to_platform_device(dev), *connector_pdev;
        struct dw_hdmi_plat_data *plat_data;
        struct drm_device *drm = data;
        struct device_node *phy_node;
@@ -150,16 +174,30 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
                return PTR_ERR(hdmi->regulator);
        }
 
+       ret = sun8i_dw_hdmi_find_connector_pdev(dev, &connector_pdev);
+       if (!ret) {
+               hdmi->ddc_en = gpiod_get_optional(&connector_pdev->dev,
+                                                 "ddc-en", GPIOD_OUT_HIGH);
+               platform_device_put(connector_pdev);
+
+               if (IS_ERR(hdmi->ddc_en)) {
+                       dev_err(dev, "Couldn't get ddc-en gpio\n");
+                       return PTR_ERR(hdmi->ddc_en);
+               }
+       }
+
        ret = regulator_enable(hdmi->regulator);
        if (ret) {
                dev_err(dev, "Failed to enable regulator\n");
-               return ret;
+               goto err_unref_ddc_en;
        }
 
+       gpiod_set_value(hdmi->ddc_en, 1);
+
        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_en;
        }
 
        ret = clk_prepare_enable(hdmi->clk_tmds);
@@ -212,8 +250,12 @@ err_disable_clk_tmds:
        clk_disable_unprepare(hdmi->clk_tmds);
 err_assert_ctrl_reset:
        reset_control_assert(hdmi->rst_ctrl);
-err_disable_regulator:
+err_disable_ddc_en:
+       gpiod_set_value(hdmi->ddc_en, 0);
        regulator_disable(hdmi->regulator);
+err_unref_ddc_en:
+       if (hdmi->ddc_en)
+               gpiod_put(hdmi->ddc_en);
 
        return ret;
 }
@@ -227,7 +269,11 @@ 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);
+       gpiod_set_value(hdmi->ddc_en, 0);
        regulator_disable(hdmi->regulator);
+
+       if (hdmi->ddc_en)
+               gpiod_put(hdmi->ddc_en);
 }
 
 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 720c5aa8adc14288ff1d44fe6d66fb498da41b47..d707c9171824043a7938585bc4e3fddb0ba0095a 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -9,6 +9,7 @@
 #include <drm/bridge/dw_hdmi.h>
 #include <drm/drm_encoder.h>
 #include <linux/clk.h>
+#include <linux/gpio/consumer.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/reset.h>
@@ -190,6 +191,7 @@ struct sun8i_dw_hdmi {
        struct regulator                *regulator;
        const struct sun8i_dw_hdmi_quirks *quirks;
        struct reset_control            *rst_ctrl;
+       struct gpio_desc                *ddc_en;
 };
 
 static inline struct sun8i_dw_hdmi *