drm/bridge: ti-sn65dsi86: Read EDID blob over DDC

Use the DDC connection to read the EDID from the eDP panel instead of
relying on the panel to tell us the modes.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102181144.3469197-4-swboyd@chromium.org

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index fbc3fe427d1aaccb62d5201b24f6d33c8ce8d28a..22d38df27a11403127ca43b9ed106d8d1951a855 100644 (file)
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -121,6 +121,7 @@
  * @debugfs:      Used for managing our debugfs.
  * @host_node:    Remote DSI node.
  * @dsi:          Our MIPI DSI source.
+ * @edid:         Detected EDID of eDP panel.
  * @refclk:       Our reference clock.
  * @panel:        Our panel.
  * @enable_gpio:  The GPIO we toggle to enable the bridge.
@@ -146,6 +147,7 @@ struct ti_sn_bridge {
        struct drm_bridge               bridge;
        struct drm_connector            connector;
        struct dentry                   *debugfs;
+       struct edid                     *edid;
        struct device_node              *host_node;
        struct mipi_dsi_device          *dsi;
        struct clk                      *refclk;
@@ -267,6 +269,23 @@ connector_to_ti_sn_bridge(struct drm_connector *connector)
 static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
 {
        struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
+       struct edid *edid = pdata->edid;
+       int num, ret;
+
+       if (!edid) {
+               pm_runtime_get_sync(pdata->dev);
+               edid = pdata->edid = drm_get_edid(connector, &pdata->aux.ddc);
+               pm_runtime_put(pdata->dev);
+       }
+
+       if (edid && drm_edid_is_valid(edid)) {
+               ret = drm_connector_update_edid_property(connector, edid);
+               if (!ret) {
+                       num = drm_add_edid_modes(connector, edid);
+                       if (num)
+                               return num;
+               }
+       }
 
        return drm_panel_get_modes(pdata->panel, connector);
 }
@@ -1262,6 +1281,7 @@ static int ti_sn_bridge_remove(struct i2c_client *client)
        if (!pdata)
                return -EINVAL;
 
+       kfree(pdata->edid);
        ti_sn_debugfs_remove(pdata);
 
        of_node_put(pdata->host_node);