From: Alexandre Courbot <[email protected]> Add the structs and function declarations for the new virtio-media drvier.
Signed-off-by: Alexandre Courbot <[email protected]> Co-developed-by: Brian Daniels <[email protected]> Signed-off-by: Brian Daniels <[email protected]> --- drivers/media/virtio/virtio_media.h | 95 +++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 drivers/media/virtio/virtio_media.h diff --git a/drivers/media/virtio/virtio_media.h b/drivers/media/virtio/virtio_media.h new file mode 100644 index 000000000..52809d4e9 --- /dev/null +++ b/drivers/media/virtio/virtio_media.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0+ */ + +/* + * Virtio-media structures & functions declarations. + * + * Copyright (c) 2024-2025 Google LLC. + */ + +#ifndef __VIRTIO_MEDIA_H +#define __VIRTIO_MEDIA_H + +#include <linux/virtio_config.h> +#include <media/v4l2-device.h> + +#include "protocol.h" + +#define DESC_CHAIN_MAX_LEN SG_MAX_SINGLE_ALLOC + +#define VIRTIO_MEDIA_DEFAULT_DRIVER_NAME "virtio-media" + +extern char *virtio_media_driver_name; +extern bool virtio_media_allow_userptr; + +/** + * struct virtio_media - Virtio-media device. + * @v4l2_dev: v4l2_device for the media device. + * @video_dev: video_device for the media device. + * @virtio_dev: virtio device for the media device. + * @commandq: virtio command queue. + * @eventq: virtio event queue. + * @eventq_work: work to run when events are received on @eventq. + * @mmap_region: region into which MMAP buffers are mapped by the host. + * @event_buffer: buffer for event descriptors. + * @sessions: list of active sessions on the device. + * @sessions_lock: protects @sessions and ``virtio_media_session::list``. + * @events_lock: prevents concurrent processing of events. + * @cmd: union of the device commands "open" and "munmap". The other + * commands are handled by @struct virtio_media_session + * @resp: union of responses.to device commands "open" and "munmap". The + * other responses are handled by @struct virtio_media_session + * @vlock: serializes access to the command queue. + * @wq: waitqueue for host responses on the command queue. + */ +struct virtio_media { + struct v4l2_device v4l2_dev; + struct video_device video_dev; + + struct virtio_device *virtio_dev; + struct virtqueue *commandq; + struct virtqueue *eventq; + struct work_struct eventq_work; + + struct virtio_shm_region mmap_region; + + void *event_buffer; + + struct list_head sessions; + struct mutex sessions_lock; /* protects sessions list */ + + struct mutex events_lock; /* prevents concurrent event processing */ + + union { + struct virtio_media_cmd_open open; + struct virtio_media_cmd_munmap munmap; + } cmd; + + union { + struct virtio_media_resp_open open; + struct virtio_media_resp_munmap munmap; + } resp; + + struct mutex vlock; /* serializes command queue access */ + wait_queue_head_t wq; +}; + +static inline struct virtio_media * +to_virtio_media(struct video_device *video_dev) +{ + return container_of(video_dev, struct virtio_media, video_dev); +} + +/* virtio_media_driver.c */ + +int virtio_media_send_command(struct virtio_media *vv, struct scatterlist **sgs, + const size_t out_sgs, const size_t in_sgs, + size_t minimum_resp_len, size_t *resp_len); +void virtio_media_process_events(struct virtio_media *vv); + +/* virtio_media_ioctls.c */ + +long virtio_media_device_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); +extern const struct v4l2_ioctl_ops virtio_media_ioctl_ops; + +#endif // __VIRTIO_MEDIA_H -- 2.55.0.rc0.799.gd6f94ed593-goog
