diff options
Diffstat (limited to 'drivers/media/test-drivers/vimc/vimc-streamer.c')
| -rw-r--r-- | drivers/media/test-drivers/vimc/vimc-streamer.c | 238 |
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 000000000000..65feb3c596db --- /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_entity_remote_pad(&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; +} |