staging: bcm2835-camera: Provide more specific probe error messages

Currently there is only a catch-all info message which print the
relevant error code without any context. So add more specific error
messages in order to narrow down possible issues.

Signed-off-by: Stefan Wahren <[e-mail]>
Reviewed-by: Nicolas Saenz Julienne <[e-mail]>
Reviewed-by: Dan Carpenter <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c

···
 	struct vchiq_mmal_component  *camera;
 
 	ret = vchiq_mmal_init(&dev->instance);
-	if (ret < 0)
+	if (ret < 0) {
+		v4l2_err(&dev->v4l2_dev, "%s: vchiq mmal init failed %d\n",
+			 __func__, ret);
 		return ret;
+	}
 
 	/* get the camera component ready */
 	ret = vchiq_mmal_component_init(dev->instance, "ril.camera",
···
 		goto unreg_mmal;
 
 	camera = dev->component[MMAL_COMPONENT_CAMERA];
-	if (camera->outputs <  MMAL_CAMERA_PORT_COUNT) {
+	if (camera->outputs < MMAL_CAMERA_PORT_COUNT) {
+		v4l2_err(&dev->v4l2_dev, "%s: too few camera outputs %d needed %d\n",
+			 __func__, camera->outputs, MMAL_CAMERA_PORT_COUNT);
 		ret = -EINVAL;
 		goto unreg_camera;
 	}
···
 	ret = set_camera_parameters(dev->instance,
 				    camera,
 				    dev);
-	if (ret < 0)
+	if (ret < 0) {
+		v4l2_err(&dev->v4l2_dev, "%s: unable to set camera parameters: %d\n",
+			 __func__, ret);
 		goto unreg_camera;
+	}
 
 	/* There was an error in the firmware that meant the camera component
 	 * produced BGR instead of RGB.
···
 
 	if (dev->component[MMAL_COMPONENT_PREVIEW]->inputs < 1) {
 		ret = -EINVAL;
-		pr_debug("too few input ports %d needed %d\n",
-			 dev->component[MMAL_COMPONENT_PREVIEW]->inputs, 1);
+		v4l2_err(&dev->v4l2_dev, "%s: too few input ports %d needed %d\n",
+			 __func__, dev->component[MMAL_COMPONENT_PREVIEW]->inputs, 1);
 		goto unreg_preview;
 	}
 
···
 
 	if (dev->component[MMAL_COMPONENT_IMAGE_ENCODE]->inputs < 1) {
 		ret = -EINVAL;
-		v4l2_err(&dev->v4l2_dev, "too few input ports %d needed %d\n",
-			 dev->component[MMAL_COMPONENT_IMAGE_ENCODE]->inputs,
+		v4l2_err(&dev->v4l2_dev, "%s: too few input ports %d needed %d\n",
+			 __func__, dev->component[MMAL_COMPONENT_IMAGE_ENCODE]->inputs,
 			 1);
 		goto unreg_image_encoder;
 	}
···
 
 	if (dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->inputs < 1) {
 		ret = -EINVAL;
-		v4l2_err(&dev->v4l2_dev, "too few input ports %d needed %d\n",
-			 dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->inputs,
+		v4l2_err(&dev->v4l2_dev, "%s: too few input ports %d needed %d\n",
+			 __func__, dev->component[MMAL_COMPONENT_VIDEO_ENCODE]->inputs,
 			 1);
 		goto unreg_vid_encoder;
 	}
···
 					      sizeof(enable));
 	}
 	ret = bm2835_mmal_set_all_camera_controls(dev);
-	if (ret < 0)
+	if (ret < 0) {
+		v4l2_err(&dev->v4l2_dev, "%s: failed to set all camera controls: %d\n",
+			 __func__, ret);
 		goto unreg_vid_encoder;
+	}
 
 	return 0;
 
···
 		snprintf(dev->v4l2_dev.name, sizeof(dev->v4l2_dev.name),
 			 "%s", BM2835_MMAL_MODULE_NAME);
 		ret = v4l2_device_register(NULL, &dev->v4l2_dev);
-		if (ret)
+		if (ret) {
+			dev_err(&pdev->dev, "%s: could not register V4L2 device: %d\n",
+				__func__, ret);
 			goto free_dev;
+		}
 
 		/* setup v4l controls */
 		ret = bm2835_mmal_init_controls(dev, &dev->ctrl_handler);
-		if (ret < 0)
+		if (ret < 0) {
+			v4l2_err(&dev->v4l2_dev, "%s: could not init controls: %d\n",
+				 __func__, ret);
 			goto unreg_dev;
+		}
 		dev->v4l2_dev.ctrl_handler = &dev->ctrl_handler;
 
 		/* mmal init */
 		dev->instance = instance;
 		ret = mmal_init(dev);
-		if (ret < 0)
+		if (ret < 0) {
+			v4l2_err(&dev->v4l2_dev, "%s: mmal init failed: %d\n",
+				 __func__, ret);
 			goto unreg_dev;
-
+		}
 		/* initialize queue */
 		q = &dev->capture.vb_vidq;
 		memset(q, 0, sizeof(*q));
···
 
 		/* initialise video devices */
 		ret = bm2835_mmal_init_device(dev, &dev->vdev);
-		if (ret < 0)
+		if (ret < 0) {
+			v4l2_err(&dev->v4l2_dev, "%s: could not init device: %d\n",
+				 __func__, ret);
 			goto unreg_dev;
+		}
 
 		/* Really want to call vidioc_s_fmt_vid_cap with the default
 		 * format, but currently the APIs don't join up.
 		 */
 		ret = mmal_setup_components(dev, &default_v4l2_format);
 		if (ret < 0) {
-			v4l2_err(&dev->v4l2_dev,
-				 "%s: could not setup components\n", __func__);
+			v4l2_err(&dev->v4l2_dev, "%s: could not setup components: %d\n",
+				 __func__, ret);
 			goto unreg_dev;
 		}
 
···
 		bcm2835_cleanup_instance(gdev[i]);
 		gdev[i] = NULL;
 	}
-	pr_info("%s: error %d while loading driver\n",
-		BM2835_MMAL_MODULE_NAME, ret);
 
 cleanup_mmal:
 	vchiq_mmal_finalise(instance);