media: Split v4l2_pipeline_pm_use into v4l2_pipeline_pm_{get, put}

Currently, v4l2_pipeline_pm_use() prototype is:

  int v4l2_pipeline_pm_use(struct media_entity *entity, int use)

Where the 'use' argument shall only be set to '1' for enable/power-on,
or to '0' for disable/power-off. The integer return is specified
as only meaningful when 'use' is set to '1'.

Let's enforce this semantic by splitting the function in two:
v4l2_pipeline_pm_get and v4l2_pipeline_pm_put. This is done
for several reasons.

It makes the API easier to use (or harder to misuse).
It removes the constraint on the values the 'use' argument
shall take. Also, it removes the need to constraint
the return value, by making v4l2_pipeline_pm_put void return.

And last, it's more consistent with other kernel APIs, such
as the runtime pm APIs, which makes the code more symmetric.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

9 files changed, 34 insertions, 25 deletions

diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
index 0ed250ffd95b..6f769c527fae 100644
--- a/drivers/media/platform/omap3isp/ispvideo.c
+++ b/drivers/media/platform/omap3isp/ispvideo.c
@@ -1311,7 +1311,7 @@ static int isp_video_open(struct file *file)
 		goto done;
 	}
 
-	ret = v4l2_pipeline_pm_use(&video->video.entity, 1);
+	ret = v4l2_pipeline_pm_get(&video->video.entity);
 	if (ret < 0) {
 		omap3isp_put(video->isp);
 		goto done;
@@ -1363,7 +1363,7 @@ static int isp_video_release(struct file *file)
 	vb2_queue_release(&handle->queue);
 	mutex_unlock(&video->queue_lock);
 
-	v4l2_pipeline_pm_use(&video->video.entity, 0);
+	v4l2_pipeline_pm_put(&video->video.entity);
 
 	/* Release the file handle. */
 	v4l2_fh_del(vfh);
diff --git a/drivers/media/platform/qcom/camss/camss-video.c b/drivers/media/platform/qcom/camss/camss-video.c
index c4220778ad47..cdbd6dba1122 100644
--- a/drivers/media/platform/qcom/camss/camss-video.c
+++ b/drivers/media/platform/qcom/camss/camss-video.c
@@ -745,7 +745,7 @@ static int video_open(struct file *file)
 
 	file->private_data = vfh;
 
-	ret = v4l2_pipeline_pm_use(&vdev->entity, 1);
+	ret = v4l2_pipeline_pm_get(&vdev->entity);
 	if (ret < 0) {
 		dev_err(video->camss->dev, "Failed to power up pipeline: %d\n",
 			ret);
@@ -771,7 +771,7 @@ static int video_release(struct file *file)
 
 	vb2_fop_release(file);
 
-	v4l2_pipeline_pm_use(&vdev->entity, 0);
+	v4l2_pipeline_pm_put(&vdev->entity);
 
 	file->private_data = NULL;
 
diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c b/drivers/media/platform/rcar-vin/rcar-v4l2.c
index b12b3f88836a..5151a3cd8a6e 100644
--- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
+++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
@@ -842,7 +842,7 @@ static int rvin_open(struct file *file)
 		goto err_unlock;
 
 	if (vin->info->use_mc)
-		ret = v4l2_pipeline_pm_use(&vin->vdev.entity, 1);
+		ret = v4l2_pipeline_pm_get(&vin->vdev.entity);
 	else if (v4l2_fh_is_singular_file(file))
 		ret = rvin_power_parallel(vin, true);
 
@@ -858,7 +858,7 @@ static int rvin_open(struct file *file)
 	return 0;
 err_power:
 	if (vin->info->use_mc)
-		v4l2_pipeline_pm_use(&vin->vdev.entity, 0);
+		v4l2_pipeline_pm_put(&vin->vdev.entity);
 	else if (v4l2_fh_is_singular_file(file))
 		rvin_power_parallel(vin, false);
 err_open:
@@ -886,7 +886,7 @@ static int rvin_release(struct file *file)
 	ret = _vb2_fop_release(file, NULL);
 
 	if (vin->info->use_mc) {
-		v4l2_pipeline_pm_use(&vin->vdev.entity, 0);
+		v4l2_pipeline_pm_put(&vin->vdev.entity);
 	} else {
 		if (fh_singular)
 			rvin_power_parallel(vin, false);
diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
index 5aee3fd875ad..1721e5aee9c6 100644
--- a/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c
@@ -214,7 +214,7 @@ static int sun4i_csi_open(struct file *file)
 	if (ret < 0)
 		goto err_pm_put;
 
-	ret = v4l2_pipeline_pm_use(&csi->vdev.entity, 1);
+	ret = v4l2_pipeline_pm_get(&csi->vdev.entity);
 	if (ret)
 		goto err_pm_put;
 
@@ -227,7 +227,7 @@ static int sun4i_csi_open(struct file *file)
 	return 0;
 
 err_pipeline_pm_put:
-	v4l2_pipeline_pm_use(&csi->vdev.entity, 0);
+	v4l2_pipeline_pm_put(&csi->vdev.entity);
 
 err_pm_put:
 	pm_runtime_put(csi->dev);
@@ -243,7 +243,7 @@ static int sun4i_csi_release(struct file *file)
 	mutex_lock(&csi->lock);
 
 	v4l2_fh_release(file);
-	v4l2_pipeline_pm_use(&csi->vdev.entity, 0);
+	v4l2_pipeline_pm_put(&csi->vdev.entity);
 	pm_runtime_put(csi->dev);
 
 	mutex_unlock(&csi->lock);
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
index cb30efb5d1f1..d9648b2810b9 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_video.c
@@ -474,7 +474,7 @@ static int sun6i_video_open(struct file *file)
 	if (ret < 0)
 		goto unlock;
 
-	ret = v4l2_pipeline_pm_use(&video->vdev.entity, 1);
+	ret = v4l2_pipeline_pm_get(&video->vdev.entity);
 	if (ret < 0)
 		goto fh_release;
 
@@ -507,7 +507,7 @@ static int sun6i_video_close(struct file *file)
 
 	_vb2_fop_release(file, NULL);
 
-	v4l2_pipeline_pm_use(&video->vdev.entity, 0);
+	v4l2_pipeline_pm_put(&video->vdev.entity);
 
 	if (last_fh)
 		sun6i_csi_set_power(video->csi, false);
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 014a2a97cadd..0fffdd3ce6a4 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -321,7 +321,7 @@ EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
  * use_count field stores the total number of users of all video device nodes
  * in the pipeline.
  *
- * The v4l2_pipeline_pm_use() function must be called in the open() and
+ * The v4l2_pipeline_pm_{get, put}() functions must be called in the open() and
  * close() handlers of video device nodes. It increments or decrements the use
  * count of all subdev entities in the pipeline.
  *
@@ -423,7 +423,7 @@ static int pipeline_pm_power(struct media_entity *entity, int change,
 	return ret;
 }
 
-int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
+static int v4l2_pipeline_pm_use(struct media_entity *entity, unsigned int use)
 {
 	struct media_device *mdev = entity->graph_obj.mdev;
 	int change = use ? 1 : -1;
@@ -444,7 +444,19 @@ int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_use);
+
+int v4l2_pipeline_pm_get(struct media_entity *entity)
+{
+	return v4l2_pipeline_pm_use(entity, 1);
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_get);
+
+void v4l2_pipeline_pm_put(struct media_entity *entity)
+{
+	/* Powering off entities shouldn't fail. */
+	WARN_ON(v4l2_pipeline_pm_use(entity, 0));
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_put);
 
 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
 			      unsigned int notification)
diff --git a/drivers/staging/media/imx/imx-media-capture.c b/drivers/staging/media/imx/imx-media-capture.c
index 0dd6a2fafd89..d37b776ff86d 100644
--- a/drivers/staging/media/imx/imx-media-capture.c
+++ b/drivers/staging/media/imx/imx-media-capture.c
@@ -643,7 +643,7 @@ static int capture_open(struct file *file)
 	if (ret)
 		v4l2_err(priv->src_sd, "v4l2_fh_open failed\n");
 
-	ret = v4l2_pipeline_pm_use(&vfd->entity, 1);
+	ret = v4l2_pipeline_pm_get(&vfd->entity);
 	if (ret)
 		v4l2_fh_release(file);
 
@@ -664,7 +664,7 @@ static int capture_release(struct file *file)
 		vq->owner = NULL;
 	}
 
-	v4l2_pipeline_pm_use(&vfd->entity, 0);
+	v4l2_pipeline_pm_put(&vfd->entity);
 
 	v4l2_fh_release(file);
 	mutex_unlock(&priv->mutex);
diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
index bf7e999998c3..66975a37dc85 100644
--- a/drivers/staging/media/omap4iss/iss_video.c
+++ b/drivers/staging/media/omap4iss/iss_video.c
@@ -1111,7 +1111,7 @@ static int iss_video_open(struct file *file)
 		goto done;
 	}
 
-	ret = v4l2_pipeline_pm_use(&video->video.entity, 1);
+	ret = v4l2_pipeline_pm_get(&video->video.entity);
 	if (ret < 0) {
 		omap4iss_put(video->iss);
 		goto done;
@@ -1160,7 +1160,7 @@ static int iss_video_release(struct file *file)
 	/* Disable streaming and free the buffers queue resources. */
 	iss_video_streamoff(file, vfh, video->type);
 
-	v4l2_pipeline_pm_use(&video->video.entity, 0);
+	v4l2_pipeline_pm_put(&video->video.entity);
 
 	/* Release the videobuf2 queue */
 	vb2_queue_release(&handle->queue);
diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c
index 7cc2ace193d1..026470c7b43d 100644
--- a/drivers/staging/media/rkisp1/rkisp1-capture.c
+++ b/drivers/staging/media/rkisp1/rkisp1-capture.c
@@ -937,10 +937,7 @@ static void rkisp1_vb2_stop_streaming(struct vb2_queue *queue)
 
 	rkisp1_return_all_buffers(cap, VB2_BUF_STATE_ERROR);
 
-	ret = v4l2_pipeline_pm_use(&node->vdev.entity, 0);
-	if (ret)
-		dev_err(rkisp1->dev, "pipeline close failed error:%d\n", ret);
-
+	v4l2_pipeline_pm_put(&node->vdev.entity);
 	ret = pm_runtime_put(rkisp1->dev);
 	if (ret)
 		dev_err(rkisp1->dev, "power down failed error:%d\n", ret);
@@ -999,7 +996,7 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
 		dev_err(cap->rkisp1->dev, "power up failed %d\n", ret);
 		goto err_destroy_dummy;
 	}
-	ret = v4l2_pipeline_pm_use(entity, 1);
+	ret = v4l2_pipeline_pm_get(entity);
 	if (ret) {
 		dev_err(cap->rkisp1->dev, "open cif pipeline failed %d\n", ret);
 		goto err_pipe_pm_put;
@@ -1025,7 +1022,7 @@ err_pipe_disable:
 	rkisp1_pipeline_sink_walk(entity, NULL, rkisp1_pipeline_disable_cb);
 err_stop_stream:
 	rkisp1_stream_stop(cap);
-	v4l2_pipeline_pm_use(entity, 0);
+	v4l2_pipeline_pm_put(entity);
 err_pipe_pm_put:
 	pm_runtime_put(cap->rkisp1->dev);
 err_destroy_dummy: