drm/bridge: ti-sn65dsi86: make use of debugfs_init callback

[ Upstream commit 1d1f7b15cb9c11974cebfd39da51dc69b8cb31ff ]

Do not create a custom directory in debugfs-root, but use the
debugfs_init callback to create a custom directory at the given place
for the bridge. The new directory layout looks like this on a Renesas
GrayHawk-Single with a R-Car V4M SoC:

	/sys/kernel/debug/dri/feb00000.display/DP-1/1-002c

Signed-off-by: Wolfram Sang <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Stable-dep-of: 55e8ff842051 ("drm/bridge: ti-sn65dsi86: Add HPD for DisplayPort connector type")
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit 1c9a8a84c5a8023567642d433d5be85f8f7929c0)

Author: Wolfram Sang

drivers/gpu/drm/bridge/ti-sn65dsi86.c

@@ -424,36 +424,8 @@ static int status_show(struct seq_file *s, void *data)
 
 	return 0;
 }
-
 DEFINE_SHOW_ATTRIBUTE(status);
 
-static void ti_sn65dsi86_debugfs_remove(void *data)
-{
-	debugfs_remove_recursive(data);
-}
-
-static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
-{
-	struct device *dev = pdata->dev;
-	struct dentry *debugfs;
-	int ret;
-
-	debugfs = debugfs_create_dir(dev_name(dev), NULL);
-
-	/*
-	 * We might get an error back if debugfs wasn't enabled in the kernel
-	 * so let's just silently return upon failure.
-	 */
-	if (IS_ERR_OR_NULL(debugfs))
-		return;
-
-	ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
-	if (ret)
-		return;
-
-	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
-}
-
 /* -----------------------------------------------------------------------------
  * Auxiliary Devices (*not* AUX)
  */
@@ -1217,6 +1189,15 @@ static struct edid *ti_sn_bridge_get_edid(struct drm_bridge *bridge,
 	return drm_get_edid(connector, &pdata->aux.ddc);
 }
 
+static void ti_sn65dsi86_debugfs_init(struct drm_bridge *bridge, struct dentry *root)
+{
+	struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge);
+	struct dentry *debugfs;
+
+	debugfs = debugfs_create_dir(dev_name(pdata->dev), root);
+	debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
+}
+
 static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
 	.attach = ti_sn_bridge_attach,
 	.detach = ti_sn_bridge_detach,
@@ -1230,6 +1211,7 @@ static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
 	.atomic_reset = drm_atomic_helper_bridge_reset,
 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.debugfs_init = ti_sn65dsi86_debugfs_init,
 };
 
 static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
@@ -1935,8 +1917,6 @@ static int ti_sn65dsi86_probe(struct i2c_client *client)
 	if (ret)
 		return ret;
 
-	ti_sn65dsi86_debugfs_init(pdata);
-
 	/*
 	 * Break ourselves up into a collection of aux devices. The only real
 	 * motiviation here is to solve the chicken-and-egg problem of probe