drm/sun4i: hdmi: add support for ddc-i2c-bus property

Sometimes it is desirabled to use a separate i2c controller for ddc
access.  This adds support for the ddc-i2c-bus property of the
hdmi-connector node, using the specified controller if provided.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190328130249.19356-1-mans@mansr.com

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi.h b/drivers/gpu/drm/sun4i/sun4i_hdmi.h
index b685ee1..b08c445 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi.h
@@ -269,6 +269,7 @@ struct sun4i_hdmi {
        struct clk              *tmds_clk;
 
        struct i2c_adapter      *i2c;
+       struct i2c_adapter      *ddc_i2c;
 
        /* Regmap fields for I2C adapter */
        struct regmap_field     *field_ddc_en;

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index d188626..8c122e6 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -217,7 +217,7 @@ static int sun4i_hdmi_get_modes(struct drm_connector *connector)
        struct edid *edid;
        int ret;
 
-       edid = drm_get_edid(connector, hdmi->i2c);
+       edid = drm_get_edid(connector, hdmi->ddc_i2c ?: hdmi->i2c);
        if (!edid)
                return 0;
 
@@ -233,6 +233,28 @@ static int sun4i_hdmi_get_modes(struct drm_connector *connector)
        return ret;
 }
 
+static struct i2c_adapter *sun4i_hdmi_get_ddc(struct device *dev)
+{
+       struct device_node *phandle, *remote;
+       struct i2c_adapter *ddc;
+
+       remote = of_graph_get_remote_node(dev->of_node, 1, -1);
+       if (!remote)
+               return ERR_PTR(-EINVAL);
+
+       phandle = of_parse_phandle(remote, "ddc-i2c-bus", 0);
+       of_node_put(remote);
+       if (!phandle)
+               return ERR_PTR(-ENODEV);
+
+       ddc = of_get_i2c_adapter_by_node(phandle);
+       of_node_put(phandle);
+       if (!ddc)
+               return ERR_PTR(-EPROBE_DEFER);
+
+       return ddc;
+}
+
 static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = {
        .get_modes      = sun4i_hdmi_get_modes,
 };
@@ -580,6 +602,15 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
                goto err_disable_mod_clk;
        }
 
+       hdmi->ddc_i2c = sun4i_hdmi_get_ddc(dev);
+       if (IS_ERR(hdmi->ddc_i2c)) {
+               ret = PTR_ERR(hdmi->ddc_i2c);
+               if (ret == -ENODEV)
+                       hdmi->ddc_i2c = NULL;
+               else
+                       goto err_del_i2c_adapter;
+       }
+
        drm_encoder_helper_add(&hdmi->encoder,
                               &sun4i_hdmi_helper_funcs);
        ret = drm_encoder_init(drm,
@@ -589,14 +620,14 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
                               NULL);
        if (ret) {
                dev_err(dev, "Couldn't initialise the HDMI encoder\n");
-               goto err_del_i2c_adapter;
+               goto err_put_ddc_i2c;
        }
 
        hdmi->encoder.possible_crtcs = drm_of_find_possible_crtcs(drm,
                                                                  dev->of_node);
        if (!hdmi->encoder.possible_crtcs) {
                ret = -EPROBE_DEFER;
-               goto err_del_i2c_adapter;
+               goto err_put_ddc_i2c;
        }
 
 #ifdef CONFIG_DRM_SUN4I_HDMI_CEC
@@ -635,6 +666,8 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
 err_cleanup_connector:
        cec_delete_adapter(hdmi->cec_adap);
        drm_encoder_cleanup(&hdmi->encoder);
+err_put_ddc_i2c:
+       i2c_put_adapter(hdmi->ddc_i2c);
 err_del_i2c_adapter:
        i2c_del_adapter(hdmi->i2c);
 err_disable_mod_clk:
@@ -655,6 +688,7 @@ static void sun4i_hdmi_unbind(struct device *dev, struct device *master,
        drm_connector_cleanup(&hdmi->connector);
        drm_encoder_cleanup(&hdmi->encoder);
        i2c_del_adapter(hdmi->i2c);
+       i2c_put_adapter(hdmi->ddc_i2c);
        clk_disable_unprepare(hdmi->mod_clk);
        clk_disable_unprepare(hdmi->bus_clk);
 }