[PATCH v10 02/18] drm: bridge: panel: Add devm_drm_of_dsi_get_bridge helper

[Jagan Teki <jagan@amarulasolutions.com>]

Add devm OF helper to return the next DSI bridge in the chain.

Unlike general bridge return helper devm_drm_of_get_bridge, this
helper uses the dsi specific panel_or_bridge helper to find the
next DSI device in the pipeline.

Helper lookup a given child DSI node or a DT node's port and
endpoint number, find the connected node and return either
the associated struct drm_panel or drm_bridge device.

Cc: Maxime Ripard <mripard@kernel.org>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v10:
- new patch

 drivers/gpu/drm/bridge/panel.c | 34 ++++++++++++++++++++++++++++++++++
 include/drm/drm_bridge.h       |  2 ++
 2 files changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
index 03c3274dc3d9..50ea5de45197 100644
--- a/drivers/gpu/drm/bridge/panel.c
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -496,4 +496,38 @@ struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
 }
 EXPORT_SYMBOL(drmm_of_get_bridge);
 
+/**
+ * devm_drm_of_dsi_get_bridge - Return next DSI bridge in the chain
+ * @dev: device to tie the bridge lifetime to
+ * @np: device tree node containing encoder output ports
+ * @port: port in the device tree node
+ * @endpoint: endpoint in the device tree node
+ *
+ * Lookup a given child DSI node or a DT node's port and endpoint number,
+ * find the connected node and return either the associated struct drm_panel
+ * or drm_bridge device. Either @panel or @bridge must not be NULL.
+ *
+ * Returns a pointer to the bridge if successful, or an error pointer
+ * otherwise.
+ */
+struct drm_bridge *devm_drm_of_dsi_get_bridge(struct device *dev,
+					      struct device_node *np,
+					      u32 port, u32 endpoint)
+{
+	struct drm_bridge *bridge;
+	struct drm_panel *panel;
+	int ret;
+
+	ret = drm_of_dsi_find_panel_or_bridge(np, port, endpoint,
+					      &panel, &bridge);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (panel)
+		bridge = devm_drm_panel_bridge_add(dev, panel);
+
+	return bridge;
+}
+EXPORT_SYMBOL(devm_drm_of_dsi_get_bridge);
+
 #endif
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 42f86327b40a..ccb14e361d3f 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -931,6 +931,8 @@ struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node
 					  u32 port, u32 endpoint);
 struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
 					  u32 port, u32 endpoint);
+struct drm_bridge *devm_drm_of_dsi_get_bridge(struct device *dev, struct device_node *node,
+					      u32 port, u32 endpoint);
 #else
 static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
 							struct device_node *node,
-- 
2.25.1