drm/bridge: lt8912b: Switch to devm MIPI-DSI helpers

Let's switch to the new devm MIPI-DSI function to register and attach
our secondary device.
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211025151536.1048186-6-maxime@cerno.tech

drivers/gpu/drm/bridge/lontium-lt8912b.c

@@ -472,11 +472,11 @@ static int lt8912_attach_dsi(struct lt8912 *lt)
 		return -EPROBE_DEFER;
 	}
 
-	dsi = mipi_dsi_device_register_full(host, &info);
+	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
 	if (IS_ERR(dsi)) {
 		ret = PTR_ERR(dsi);
 		dev_err(dev, "failed to create dsi device (%d)\n", ret);
-		goto err_dsi_device;
+		return ret;
 	}
 
 	lt->dsi = dsi;
@@ -489,24 +489,13 @@ static int lt8912_attach_dsi(struct lt8912 *lt)
 			  MIPI_DSI_MODE_LPM |
 			  MIPI_DSI_MODE_NO_EOT_PACKET;
 
-	ret = mipi_dsi_attach(dsi);
+	ret = devm_mipi_dsi_attach(dev, dsi);
 	if (ret < 0) {
 		dev_err(dev, "failed to attach dsi to host\n");
-		goto err_dsi_attach;
+		return ret;
 	}
 
 	return 0;
-
-err_dsi_attach:
-	mipi_dsi_device_unregister(dsi);
-err_dsi_device:
-	return ret;
-}
-
-static void lt8912_detach_dsi(struct lt8912 *lt)
-{
-	mipi_dsi_detach(lt->dsi);
-	mipi_dsi_device_unregister(lt->dsi);
 }
 
 static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
@@ -573,7 +562,6 @@ static void lt8912_bridge_detach(struct drm_bridge *bridge)
 	struct lt8912 *lt = bridge_to_lt8912(bridge);
 
 	if (lt->is_attached) {
-		lt8912_detach_dsi(lt);
 		lt8912_hard_power_off(lt);
 		drm_connector_unregister(&lt->connector);
 		drm_connector_cleanup(&lt->connector);