drm/dsi: Support device shutdown

Hook up the MIPI DSI bus's .shutdown() function to allow drivers to
implement code that should be run when a device is shut down.
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/gpu/drm/drm_mipi_dsi.c

@@ -282,6 +282,14 @@ static int mipi_dsi_drv_remove(struct device *dev)
 	return drv->remove(dsi);
 }
 
+static void mipi_dsi_drv_shutdown(struct device *dev)
+{
+	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
+
+	drv->shutdown(dsi);
+}
+
 /**
  * mipi_dsi_driver_register - register a driver for DSI devices
  * @drv: DSI driver structure
@@ -293,6 +301,8 @@ int mipi_dsi_driver_register(struct mipi_dsi_driver *drv)
 		drv->driver.probe = mipi_dsi_drv_probe;
 	if (drv->remove)
 		drv->driver.remove = mipi_dsi_drv_remove;
+	if (drv->shutdown)
+		drv->driver.shutdown = mipi_dsi_drv_shutdown;
 
 	return driver_register(&drv->driver);
 }

include/drm/drm_mipi_dsi.h

@@ -135,11 +135,13 @@ ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, unsigned int channel,
  * @driver: device driver model driver
  * @probe: callback for device binding
  * @remove: callback for device unbinding
+ * @shutdown: called at shutdown time to quiesce the device
  */
 struct mipi_dsi_driver {
 	struct device_driver driver;
 	int(*probe)(struct mipi_dsi_device *dsi);
 	int(*remove)(struct mipi_dsi_device *dsi);
+	void (*shutdown)(struct mipi_dsi_device *dsi);
 };
 
 #define to_mipi_dsi_driver(d) container_of(d, struct mipi_dsi_driver, driver)