drm/omap: Remove unneeded safety checks in the HPD operations

The HPD-related omap_dss_device operations are now only called when the
device supports HPD. There's no need to duplicate that check in the
omap_dss_device drivers. The .register_hpd_cb() operation can as a
result be turned into a void operation.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/displays/connector-dvi.c

@@ -211,30 +211,23 @@ static bool dvic_detect(struct omap_dss_device *dssdev)
 	return r == 0;
 }
 
-static int dvic_register_hpd_cb(struct omap_dss_device *dssdev,
+static void dvic_register_hpd_cb(struct omap_dss_device *dssdev,
 				 void (*cb)(void *cb_data,
 					    enum drm_connector_status status),
 				 void *cb_data)
 {
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
 
-	if (!ddata->hpd_gpio)
-		return -ENOTSUPP;
-
 	mutex_lock(&ddata->hpd_lock);
 	ddata->hpd_cb = cb;
 	ddata->hpd_cb_data = cb_data;
 	mutex_unlock(&ddata->hpd_lock);
-	return 0;
 }
 
 static void dvic_unregister_hpd_cb(struct omap_dss_device *dssdev)
 {
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
 
-	if (!ddata->hpd_gpio)
-		return;
-
 	mutex_lock(&ddata->hpd_lock);
 	ddata->hpd_cb = NULL;
 	ddata->hpd_cb_data = NULL;

drivers/gpu/drm/omapdrm/displays/connector-hdmi.c

@@ -147,31 +147,23 @@ static bool hdmic_detect(struct omap_dss_device *dssdev)
 	return connected;
 }
 
-static int hdmic_register_hpd_cb(struct omap_dss_device *dssdev,
-				 void (*cb)(void *cb_data,
+static void hdmic_register_hpd_cb(struct omap_dss_device *dssdev,
+				  void (*cb)(void *cb_data,
 					    enum drm_connector_status status),
-				 void *cb_data)
+				  void *cb_data)
 {
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
 
-	if (!ddata->hpd_gpio)
-		return -ENOTSUPP;
-
 	mutex_lock(&ddata->hpd_lock);
 	ddata->hpd_cb = cb;
 	ddata->hpd_cb_data = cb_data;
 	mutex_unlock(&ddata->hpd_lock);
-
-	return 0;
 }
 
 static void hdmic_unregister_hpd_cb(struct omap_dss_device *dssdev)
 {
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
 
-	if (!ddata->hpd_gpio)
-		return;
-
 	mutex_lock(&ddata->hpd_lock);
 	ddata->hpd_cb = NULL;
 	ddata->hpd_cb_data = NULL;

drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c

@@ -140,10 +140,10 @@ static bool tpd_detect(struct omap_dss_device *dssdev)
 	return connected;
 }
 
-static int tpd_register_hpd_cb(struct omap_dss_device *dssdev,
-			       void (*cb)(void *cb_data,
+static void tpd_register_hpd_cb(struct omap_dss_device *dssdev,
+				void (*cb)(void *cb_data,
 					  enum drm_connector_status status),
-			       void *cb_data)
+				void *cb_data)
 {
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
 
@@ -151,8 +151,6 @@ static int tpd_register_hpd_cb(struct omap_dss_device *dssdev,
 	ddata->hpd_cb = cb;
 	ddata->hpd_cb_data = cb_data;
 	mutex_unlock(&ddata->hpd_lock);
-
-	return 0;
 }
 
 static void tpd_unregister_hpd_cb(struct omap_dss_device *dssdev)

drivers/gpu/drm/omapdrm/dss/omapdss.h

@@ -372,10 +372,10 @@ struct omap_dss_device_ops {
 
 	bool (*detect)(struct omap_dss_device *dssdev);
 
-	int (*register_hpd_cb)(struct omap_dss_device *dssdev,
-			       void (*cb)(void *cb_data,
+	void (*register_hpd_cb)(struct omap_dss_device *dssdev,
+				void (*cb)(void *cb_data,
 					  enum drm_connector_status status),
-			       void *cb_data);
+				void *cb_data);
 	void (*unregister_hpd_cb)(struct omap_dss_device *dssdev);
 	void (*enable_hpd)(struct omap_dss_device *dssdev);
 	void (*disable_hpd)(struct omap_dss_device *dssdev);

drivers/gpu/drm/omapdrm/omap_connector.c

@@ -298,19 +298,10 @@ struct drm_connector *omap_connector_init(struct drm_device *dev,
 	 */
 	dssdev = omap_connector_find_device(connector, OMAP_DSS_DEVICE_OP_HPD);
 	if (dssdev) {
-		int ret;
-
-		ret = dssdev->ops->register_hpd_cb(dssdev,
-						   omap_connector_hpd_cb,
-						   omap_connector);
-		if (ret < 0)
-			DBG("%s: Failed to register HPD callback (%d).",
-			    dssdev->name, ret);
-		else
-			connector->polled = DRM_CONNECTOR_POLL_HPD;
-	}
-
-	if (!connector->polled) {
+		dssdev->ops->register_hpd_cb(dssdev, omap_connector_hpd_cb,
+					     omap_connector);
+		connector->polled = DRM_CONNECTOR_POLL_HPD;
+	} else {
 		dssdev = omap_connector_find_device(connector,
 						    OMAP_DSS_DEVICE_OP_DETECT);
 		if (dssdev)