drm: Expose panel_info sysfs node

Change-Id: Ifafb2f5da69aa1e23cec3c9b7868afc32fee4970
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

drivers/gpu/drm/drm_bridge.c

@@ -369,6 +369,19 @@ void drm_bridge_pre_enable(struct drm_bridge *bridge)
 }
 EXPORT_SYMBOL(drm_bridge_pre_enable);
 
+int drm_get_panel_info(struct drm_bridge *bridge, char *buf)
+{
+	int rc = 0;
+	if (!bridge)
+		return rc;
+
+	if (bridge->funcs->disp_get_panel_info)
+		return bridge->funcs->disp_get_panel_info(bridge, buf);
+
+	return rc;
+}
+EXPORT_SYMBOL(drm_get_panel_info);
+
 /**
  * drm_bridge_enable - enables all bridges in the encoder chain
  * @bridge: bridge control structure

drivers/gpu/drm/drm_sysfs.c

@@ -18,6 +18,7 @@
 #include <linux/err.h>
 #include <linux/export.h>
 
+#include <drm/drm_encoder.h>
 #include <drm/drm_sysfs.h>
 #include <drm/drmP.h>
 #include "drm_internal.h"
@@ -229,16 +230,48 @@ static ssize_t modes_show(struct device *device,
 	return written;
 }
 
+extern int drm_get_panel_info(struct drm_bridge *bridge, char *name);
+static ssize_t panel_info_show(struct device *device,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	int written = 0;
+	char pname[128] = {0};
+	struct drm_connector *connector = NULL;
+	struct drm_encoder *encoder = NULL;
+	struct drm_bridge *bridge = NULL;
+
+	connector = to_drm_connector(device);
+	if (!connector)
+		return written;
+
+	encoder = connector->encoder;
+	if (!encoder)
+		return written;
+
+	bridge = encoder->bridge;
+	if (!bridge)
+		return written;
+
+	written = drm_get_panel_info(bridge, pname);
+	if (written)
+		return snprintf(buf, PAGE_SIZE, "panel_name=%s\n", pname);
+
+	return written;
+}
+
 static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(enabled);
 static DEVICE_ATTR_RO(dpms);
 static DEVICE_ATTR_RO(modes);
+static DEVICE_ATTR_RO(panel_info);
 
 static struct attribute *connector_dev_attrs[] = {
 	&dev_attr_status.attr,
 	&dev_attr_enabled.attr,
 	&dev_attr_dpms.attr,
 	&dev_attr_modes.attr,
+	&dev_attr_panel_info.attr,
 	NULL
 };
 

drivers/gpu/drm/msm/dsi-staging/dsi_drm.c

@@ -296,6 +296,22 @@ int dsi_bridge_interface_enable(int timeout)
 }
 EXPORT_SYMBOL(dsi_bridge_interface_enable);
 
+static int dsi_bridge_get_panel_info(struct drm_bridge *bridge, char *buf)
+{
+	int rc = 0;
+	struct dsi_bridge *c_bridge = to_dsi_bridge(bridge);
+
+	if (!c_bridge) {
+		pr_err("Invalid params\n");
+		return rc;
+	}
+
+	if (c_bridge->display->name)
+		return snprintf(buf, PAGE_SIZE, c_bridge->display->name);
+
+	return rc;
+}
+
 static void dsi_bridge_enable(struct drm_bridge *bridge)
 {
 	int rc = 0;
@@ -654,6 +670,7 @@ static const struct drm_bridge_funcs dsi_bridge_ops = {
 	.disable      = dsi_bridge_disable,
 	.post_disable = dsi_bridge_post_disable,
 	.mode_set     = dsi_bridge_mode_set,
+	.disp_get_panel_info = dsi_bridge_get_panel_info,
 };
 
 int dsi_conn_set_info_blob(struct drm_connector *connector,

include/drm/drm_bridge.h

@@ -236,6 +236,8 @@ struct drm_bridge_funcs {
 	 * The enable callback is optional.
 	 */
 	void (*enable)(struct drm_bridge *bridge);
+
+	int (*disp_get_panel_info)(struct drm_bridge *bridge, char *name);
 };
 
 /**