This patch adds support for scatter gather transfers. If the underlying
gadgets sg_supported == true, then the videeobuf2-dma-sg is used and the
encode routine maps all scatter entries to separate scatterlists for the
usb gadget.
Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/Kconfig | 1 +
drivers/usb/gadget/function/f_uvc.c | 1 +
drivers/usb/gadget/function/uvc.h | 2 +
drivers/usb/gadget/function/uvc_queue.c | 23 ++++++-
drivers/usb/gadget/function/uvc_queue.h | 5 +-
drivers/usb/gadget/function/uvc_video.c | 80 ++++++++++++++++++++++++-
6 files changed, 105 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 2d152571a7de8..dd58094f0b85b 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -450,6 +450,7 @@ config USB_CONFIGFS_F_UVC
depends on USB_CONFIGFS
depends on VIDEO_V4L2
depends on VIDEO_DEV
+ select VIDEOBUF2_DMA_SG
select VIDEOBUF2_VMALLOC
select USB_F_UVC
help
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index f48a00e497945..9d87c0fb8f92e 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -418,6 +418,7 @@ uvc_register_video(struct uvc_device *uvc)
/* TODO reference counting. */
uvc->vdev.v4l2_dev = &uvc->v4l2_dev;
+ uvc->vdev.v4l2_dev->dev = &cdev->gadget->dev;
uvc->vdev.fops = &uvc_v4l2_fops;
uvc->vdev.ioctl_ops = &uvc_v4l2_ioctl_ops;
uvc->vdev.release = video_device_release_empty;
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index 83b9e945944e8..c1f06d9df5820 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -75,6 +75,8 @@ struct uvc_request {
struct usb_request *req;
__u8 *req_buffer;
struct uvc_video *video;
+ struct sg_table sgt;
+ u8 header[2];
};
struct uvc_video {
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
index dcd71304d521c..e36a3506842b7 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -18,6 +18,7 @@
#include <media/v4l2-common.h>
#include <media/videobuf2-vmalloc.h>
+#include <media/videobuf2-dma-sg.h>
#include "uvc.h"
@@ -52,6 +53,7 @@ static int uvc_queue_setup(struct vb2_queue *vq,
*nplanes = 1;
sizes[0] = video->imagesize;
+ alloc_devs[0] = video->uvc->v4l2_dev.dev->parent;
if (cdev->gadget->speed < USB_SPEED_SUPER)
video->uvc_num_requests = 4;
@@ -66,6 +68,9 @@ static int uvc_buffer_prepare(struct vb2_buffer *vb)
struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct uvc_buffer *buf = container_of(vbuf, struct uvc_buffer, buf);
+ struct uvc_video *video = container_of(queue, struct uvc_video, queue);
+ struct uvc_device *uvc = video->uvc;
+ struct usb_composite_dev *cdev = uvc->func.config->cdev;
if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
@@ -77,7 +82,12 @@ static int uvc_buffer_prepare(struct vb2_buffer *vb)
return -ENODEV;
buf->state = UVC_BUF_STATE_QUEUED;
- buf->mem = vb2_plane_vaddr(vb, 0);
+ if (cdev->gadget->sg_supported) {
+ buf->sgt = vb2_dma_sg_plane_desc(vb, 0);
+ buf->sg = buf->sgt->sgl;
+ } else {
+ buf->mem = vb2_plane_vaddr(vb, 0);
+ }
buf->length = vb2_plane_size(vb, 0);
if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
buf->bytesused = 0;
@@ -117,9 +127,11 @@ static const struct vb2_ops uvc_queue_qops = {
.wait_finish = vb2_ops_wait_finish,
};
-int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
+int uvcg_queue_init(struct device *dev, struct uvc_video_queue *queue, enum v4l2_buf_type type,
struct mutex *lock)
{
+ struct uvc_video *video = container_of(queue, struct uvc_video, queue);
+ struct usb_composite_dev *cdev = video->uvc->func.config->cdev;
int ret;
queue->queue.type = type;
@@ -128,9 +140,14 @@ int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
queue->queue.ops = &uvc_queue_qops;
queue->queue.lock = lock;
- queue->queue.mem_ops = &vb2_vmalloc_memops;
+ if (cdev->gadget->sg_supported)
+ queue->queue.mem_ops = &vb2_dma_sg_memops;
+ else
+ queue->queue.mem_ops = &vb2_vmalloc_memops;
+
queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
| V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
+ queue->queue.dev = dev;
ret = vb2_queue_init(&queue->queue);
if (ret)
return ret;
diff --git a/drivers/usb/gadget/function/uvc_queue.h b/drivers/usb/gadget/function/uvc_queue.h
index 2f0fff7698430..bb8753b26074f 100644
--- a/drivers/usb/gadget/function/uvc_queue.h
+++ b/drivers/usb/gadget/function/uvc_queue.h
@@ -34,6 +34,9 @@ struct uvc_buffer {
enum uvc_buffer_state state;
void *mem;
+ struct sg_table *sgt;
+ struct scatterlist *sg;
+ unsigned int offset;
unsigned int length;
unsigned int bytesused;
};
@@ -59,7 +62,7 @@ static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
return vb2_is_streaming(&queue->queue);
}
-int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
+int uvcg_queue_init(struct device *d, struct uvc_video_queue *queue, enum v4l2_buf_type type,
struct mutex *lock);
void uvcg_free_buffers(struct uvc_video_queue *queue);
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index e7910615c8faa..85b6a4c080065 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -95,6 +95,71 @@ uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
video->payload_size = 0;
}
+static void
+uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
+ struct uvc_buffer *buf)
+{
+ int pending = buf->bytesused - video->queue.buf_used;
+ struct uvc_request *ureq = req->context;
+ struct scatterlist *sg, *iter;
+ int len = video->req_size;
+ int sg_left, part = 0;
+ int ret;
+ int i;
+
+ sg = ureq->sgt.sgl;
+ sg_init_table(sg, ureq->sgt.nents);
+
+ /* Init the header. */
+ memset(ureq->header, 0, 2);
+ ret = uvc_video_encode_header(video, buf, ureq->header,
+ video->req_size);
+ sg_set_buf(sg, ureq->header, 2);
+ len -= ret;
+
+ if (pending <= len)
+ len = pending;
+
+ req->length = (len == pending) ? len + 2 : video->req_size;
+
+ /* Init the pending sgs with payload */
+ sg = sg_next(sg);
+
+ for_each_sg(sg, iter, ureq->sgt.nents - 1, i) {
+ if (!len || !buf->sg)
+ break;
+
+ sg_left = sg_dma_len(buf->sg) - buf->offset;
+ part = min_t(unsigned int, len, sg_left);
+
+ sg_set_page(iter, sg_page(buf->sg), part, buf->offset);
+
+ if (part == sg_left) {
+ buf->offset = 0;
+ buf->sg = sg_next(buf->sg);
+ } else {
+ buf->offset += part;
+ }
+ len -= part;
+ }
+
+ /* Assign the video data with header. */
+ req->buf = NULL;
+ req->sg = ureq->sgt.sgl;
+ req->num_sgs = i + 1;
+
+ req->length -= len;
+ video->queue.buf_used += req->length - 2;
+
+ if (buf->bytesused == video->queue.buf_used || !buf->sg) {
+ video->queue.buf_used = 0;
+ buf->state = UVC_BUF_STATE_DONE;
+ buf->offset = 0;
+ uvcg_queue_next_buffer(&video->queue, buf);
+ video->fid ^= UVC_STREAM_FID;
+ }
+}
+
static void
uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
struct uvc_buffer *buf)
@@ -229,6 +294,10 @@ uvc_video_alloc_requests(struct uvc_video *video)
video->ureq[i].video = video;
list_add_tail(&video->ureq[i].req->list, &video->req_free);
+ /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */
+ sg_alloc_table(&video->ureq[i].sgt,
+ DIV_ROUND_UP(req_size - 2, PAGE_SIZE) + 2,
+ GFP_KERNEL);
}
video->req_size = req_size;
@@ -306,6 +375,7 @@ static void uvcg_video_pump(struct work_struct *work)
*/
int uvcg_video_enable(struct uvc_video *video, int enable)
{
+ struct usb_composite_dev *cdev = video->uvc->func.config->cdev;
unsigned int i;
int ret;
@@ -337,8 +407,12 @@ int uvcg_video_enable(struct uvc_video *video, int enable)
if (video->max_payload_size) {
video->encode = uvc_video_encode_bulk;
video->payload_size = 0;
- } else
- video->encode = uvc_video_encode_isoc;
+ } else {
+ if (cdev->gadget->sg_supported)
+ video->encode = uvc_video_encode_isoc_sg;
+ else
+ video->encode = uvc_video_encode_isoc;
+ }
schedule_work(&video->pump);
@@ -362,7 +436,7 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
video->imagesize = 320 * 240 * 2;
/* Initialize the video buffers queue. */
- uvcg_queue_init(&video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT,
+ uvcg_queue_init(uvc->v4l2_dev.dev, &video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT,
&video->mutex);
return 0;
}
--
2.29.2
