drm/exynos/hdmi: add bridge support

On TM2/TM2e platforms HDMI output is connected to MHL bridge
SiI8620. To allow configure UltraHD modes on the bridge
and to eliminate unsupported modes this bridge should be
attached to drm_encoder implemented in exynos_hdmi.

Changelog v1:
- fix drm_attach_bridge argument.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index a73b192094fbff6a2f548039f0ce9dda66280e47..88ccc0469316b191d75f87de57ccad301dc42145 100644 (file)
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -35,6 +35,7 @@
 #include <linux/io.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/of_graph.h>
 #include <linux/hdmi.h>
 #include <linux/component.h>
 #include <linux/mfd/syscon.h>
@@ -133,6 +134,7 @@ struct hdmi_context {
        struct regulator_bulk_data      regul_bulk[ARRAY_SIZE(supply)];
        struct regulator                *reg_hdmi_en;
        struct exynos_drm_clk           phy_clk;
+       struct drm_bridge               *bridge;
 };
 
 static inline struct hdmi_context *encoder_to_hdmi(struct drm_encoder *e)
@@ -922,7 +924,15 @@ static int hdmi_create_connector(struct drm_encoder *encoder)
        drm_connector_register(connector);
        drm_mode_connector_attach_encoder(connector, encoder);
 
-       return 0;
+       if (hdata->bridge) {
+               encoder->bridge = hdata->bridge;
+               hdata->bridge->encoder = encoder;
+               ret = drm_bridge_attach(encoder, hdata->bridge, NULL);
+               if (ret)
+                       DRM_ERROR("Failed to attach bridge\n");
+       }
+
+       return ret;
 }
 
 static bool hdmi_mode_fixup(struct drm_encoder *encoder,
@@ -1591,6 +1601,31 @@ static void hdmiphy_clk_enable(struct exynos_drm_clk *clk, bool enable)
                hdmiphy_disable(hdata);
 }
 
+static int hdmi_bridge_init(struct hdmi_context *hdata)
+{
+       struct device *dev = hdata->dev;
+       struct device_node *ep, *np;
+
+       ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
+       if (!ep)
+               return 0;
+
+       np = of_graph_get_remote_port_parent(ep);
+       of_node_put(ep);
+       if (!np) {
+               DRM_ERROR("failed to get remote port parent");
+               return -EINVAL;
+       }
+
+       hdata->bridge = of_drm_find_bridge(np);
+       of_node_put(np);
+
+       if (!hdata->bridge)
+               return -EPROBE_DEFER;
+
+       return 0;
+}
+
 static int hdmi_resources_init(struct hdmi_context *hdata)
 {
        struct device *dev = hdata->dev;
@@ -1630,17 +1665,18 @@ static int hdmi_resources_init(struct hdmi_context *hdata)
 
        hdata->reg_hdmi_en = devm_regulator_get_optional(dev, "hdmi-en");
 
-       if (PTR_ERR(hdata->reg_hdmi_en) == -ENODEV)
-               return 0;
+       if (PTR_ERR(hdata->reg_hdmi_en) != -ENODEV) {
+               if (IS_ERR(hdata->reg_hdmi_en))
+                       return PTR_ERR(hdata->reg_hdmi_en);
 
-       if (IS_ERR(hdata->reg_hdmi_en))
-               return PTR_ERR(hdata->reg_hdmi_en);
-
-       ret = regulator_enable(hdata->reg_hdmi_en);
-       if (ret)
-               DRM_ERROR("failed to enable hdmi-en regulator\n");
+               ret = regulator_enable(hdata->reg_hdmi_en);
+               if (ret) {
+                       DRM_ERROR("failed to enable hdmi-en regulator\n");
+                       return ret;
+               }
+       }
 
-       return ret;
+       return hdmi_bridge_init(hdata);
 }
 
 static struct of_device_id hdmi_match_types[] = {