drm/dsi: Add uevent callback

Implement a uevent callback for devices on the MIPI DSI bus. This
callback will append MODALIAS information to the uevent and allow
modules to be loaded when devices are added to the bus.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/drm_mipi_dsi.c

@@ -60,6 +60,21 @@ static int mipi_dsi_device_match(struct device *dev, struct device_driver *drv)
 	return 0;
 }
 
+static int mipi_dsi_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
+	int err;
+
+	err = of_device_uevent_modalias(dev, env);
+	if (err != -ENODEV)
+		return err;
+
+	add_uevent_var(env, "MODALIAS=%s%s", MIPI_DSI_MODULE_PREFIX,
+		       dsi->name);
+
+	return 0;
+}
+
 static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
 	.runtime_suspend = pm_generic_runtime_suspend,
 	.runtime_resume = pm_generic_runtime_resume,
@@ -74,6 +89,7 @@ static const struct dev_pm_ops mipi_dsi_device_pm_ops = {
 static struct bus_type mipi_dsi_bus_type = {
 	.name = "mipi-dsi",
 	.match = mipi_dsi_device_match,
+	.uevent = mipi_dsi_uevent,
 	.pm = &mipi_dsi_device_pm_ops,
 };
 

include/drm/drm_mipi_dsi.h

@@ -180,6 +180,8 @@ struct mipi_dsi_device {
 	unsigned long mode_flags;
 };
 
+#define MIPI_DSI_MODULE_PREFIX "mipi-dsi:"
+
 static inline struct mipi_dsi_device *to_mipi_dsi_device(struct device *dev)
 {
 	return container_of(dev, struct mipi_dsi_device, dev);