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 000000000..807551a51
--- /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;
+}