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Diffstat (limited to 'drivers/media/test-drivers/vimc/vimc-streamer.c')
-rw-r--r--drivers/media/test-drivers/vimc/vimc-streamer.c238
1 files changed, 238 insertions, 0 deletions
diff --git a/drivers/media/test-drivers/vimc/vimc-streamer.c b/drivers/media/test-drivers/vimc/vimc-streamer.c
new file mode 100644
index 0000000000..807551a514
--- /dev/null
+++ b/drivers/media/test-drivers/vimc/vimc-streamer.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vimc-streamer.c Virtual Media Controller Driver
+ *
+ * Copyright (C) 2018 Lucas A. M. Magalhães <lucmaga@gmail.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+
+#include "vimc-streamer.h"
+
+/**
+ * vimc_get_source_entity - get the entity connected with the first sink pad
+ *
+ * @ent: reference media_entity
+ *
+ * Helper function that returns the media entity containing the source pad
+ * linked with the first sink pad from the given media entity pad list.
+ *
+ * Return: The source pad or NULL, if it wasn't found.
+ */
+static struct media_entity *vimc_get_source_entity(struct media_entity *ent)
+{
+ struct media_pad *pad;
+ int i;
+
+ for (i = 0; i < ent->num_pads; i++) {
+ if (ent->pads[i].flags & MEDIA_PAD_FL_SOURCE)
+ continue;
+ pad = media_pad_remote_pad_first(&ent->pads[i]);
+ return pad ? pad->entity : NULL;
+ }
+ return NULL;
+}
+
+/**
+ * vimc_streamer_pipeline_terminate - Disable stream in all ved in stream
+ *
+ * @stream: the pointer to the stream structure with the pipeline to be
+ * disabled.
+ *
+ * Calls s_stream to disable the stream in each entity of the pipeline
+ *
+ */
+static void vimc_streamer_pipeline_terminate(struct vimc_stream *stream)
+{
+ struct vimc_ent_device *ved;
+ struct v4l2_subdev *sd;
+
+ while (stream->pipe_size) {
+ stream->pipe_size--;
+ ved = stream->ved_pipeline[stream->pipe_size];
+ stream->ved_pipeline[stream->pipe_size] = NULL;
+
+ if (!is_media_entity_v4l2_subdev(ved->ent))
+ continue;
+
+ sd = media_entity_to_v4l2_subdev(ved->ent);
+ v4l2_subdev_call(sd, video, s_stream, 0);
+ }
+}
+
+/**
+ * vimc_streamer_pipeline_init - Initializes the stream structure
+ *
+ * @stream: the pointer to the stream structure to be initialized
+ * @ved: the pointer to the vimc entity initializing the stream
+ *
+ * Initializes the stream structure. Walks through the entity graph to
+ * construct the pipeline used later on the streamer thread.
+ * Calls vimc_streamer_s_stream() to enable stream in all entities of
+ * the pipeline.
+ *
+ * Return: 0 if success, error code otherwise.
+ */
+static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
+ struct vimc_ent_device *ved)
+{
+ struct media_entity *entity;
+ struct video_device *vdev;
+ struct v4l2_subdev *sd;
+ int ret = 0;
+
+ stream->pipe_size = 0;
+ while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
+ if (!ved) {
+ vimc_streamer_pipeline_terminate(stream);
+ return -EINVAL;
+ }
+ stream->ved_pipeline[stream->pipe_size++] = ved;
+
+ if (is_media_entity_v4l2_subdev(ved->ent)) {
+ sd = media_entity_to_v4l2_subdev(ved->ent);
+ ret = v4l2_subdev_call(sd, video, s_stream, 1);
+ if (ret && ret != -ENOIOCTLCMD) {
+ dev_err(ved->dev, "subdev_call error %s\n",
+ ved->ent->name);
+ vimc_streamer_pipeline_terminate(stream);
+ return ret;
+ }
+ }
+
+ entity = vimc_get_source_entity(ved->ent);
+ /* Check if the end of the pipeline was reached */
+ if (!entity) {
+ /* the first entity of the pipe should be source only */
+ if (!vimc_is_source(ved->ent)) {
+ dev_err(ved->dev,
+ "first entity in the pipe '%s' is not a source\n",
+ ved->ent->name);
+ vimc_streamer_pipeline_terminate(stream);
+ return -EPIPE;
+ }
+ return 0;
+ }
+
+ /* Get the next device in the pipeline */
+ if (is_media_entity_v4l2_subdev(entity)) {
+ sd = media_entity_to_v4l2_subdev(entity);
+ ved = v4l2_get_subdevdata(sd);
+ } else {
+ vdev = container_of(entity,
+ struct video_device,
+ entity);
+ ved = video_get_drvdata(vdev);
+ }
+ }
+
+ vimc_streamer_pipeline_terminate(stream);
+ return -EINVAL;
+}
+
+/**
+ * vimc_streamer_thread - Process frames through the pipeline
+ *
+ * @data: vimc_stream struct of the current stream
+ *
+ * From the source to the sink, gets a frame from each subdevice and send to
+ * the next one of the pipeline at a fixed framerate.
+ *
+ * Return:
+ * Always zero (created as ``int`` instead of ``void`` to comply with
+ * kthread API).
+ */
+static int vimc_streamer_thread(void *data)
+{
+ struct vimc_stream *stream = data;
+ u8 *frame = NULL;
+ int i;
+
+ set_freezable();
+
+ for (;;) {
+ try_to_freeze();
+ if (kthread_should_stop())
+ break;
+
+ for (i = stream->pipe_size - 1; i >= 0; i--) {
+ frame = stream->ved_pipeline[i]->process_frame(
+ stream->ved_pipeline[i], frame);
+ if (!frame || IS_ERR(frame))
+ break;
+ }
+ //wait for 60hz
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule_timeout(HZ / 60);
+ }
+
+ return 0;
+}
+
+/**
+ * vimc_streamer_s_stream - Start/stop the streaming on the media pipeline
+ *
+ * @stream: the pointer to the stream structure of the current stream
+ * @ved: pointer to the vimc entity of the entity of the stream
+ * @enable: flag to determine if stream should start/stop
+ *
+ * When starting, check if there is no ``stream->kthread`` allocated. This
+ * should indicate that a stream is already running. Then, it initializes the
+ * pipeline, creates and runs a kthread to consume buffers through the pipeline.
+ * When stopping, analogously check if there is a stream running, stop the
+ * thread and terminates the pipeline.
+ *
+ * Return: 0 if success, error code otherwise.
+ */
+int vimc_streamer_s_stream(struct vimc_stream *stream,
+ struct vimc_ent_device *ved,
+ int enable)
+{
+ int ret;
+
+ if (!stream || !ved)
+ return -EINVAL;
+
+ if (enable) {
+ if (stream->kthread)
+ return 0;
+
+ ret = vimc_streamer_pipeline_init(stream, ved);
+ if (ret)
+ return ret;
+
+ stream->kthread = kthread_run(vimc_streamer_thread, stream,
+ "vimc-streamer thread");
+
+ if (IS_ERR(stream->kthread)) {
+ ret = PTR_ERR(stream->kthread);
+ dev_err(ved->dev, "kthread_run failed with %d\n", ret);
+ vimc_streamer_pipeline_terminate(stream);
+ stream->kthread = NULL;
+ return ret;
+ }
+
+ } else {
+ if (!stream->kthread)
+ return 0;
+
+ ret = kthread_stop(stream->kthread);
+ /*
+ * kthread_stop returns -EINTR in cases when streamon was
+ * immediately followed by streamoff, and the thread didn't had
+ * a chance to run. Ignore errors to stop the stream in the
+ * pipeline.
+ */
+ if (ret)
+ dev_dbg(ved->dev, "kthread_stop returned '%d'\n", ret);
+
+ stream->kthread = NULL;
+
+ vimc_streamer_pipeline_terminate(stream);
+ }
+
+ return 0;
+}