1 files changed, 546 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
new file mode 100644
index 000000000..e81865978
--- /dev/null
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -0,0 +1,546 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	uvc_video.c  --  USB Video Class Gadget driver
+ *
+ *	Copyright (C) 2009-2010
+ *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/video.h>
+#include <asm/unaligned.h>
+
+#include <media/v4l2-dev.h>
+
+#include "uvc.h"
+#include "uvc_queue.h"
+#include "uvc_video.h"
+
+/* --------------------------------------------------------------------------
+ * Video codecs
+ */
+
+static int
+uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf,
+		u8 *data, int len)
+{
+	struct uvc_device *uvc = container_of(video, struct uvc_device, video);
+	struct usb_composite_dev *cdev = uvc->func.config->cdev;
+	struct timespec64 ts = ns_to_timespec64(buf->buf.vb2_buf.timestamp);
+	int pos = 2;
+
+	data[1] = UVC_STREAM_EOH | video->fid;
+
+	if (video->queue.buf_used == 0 && ts.tv_sec) {
+		/* dwClockFrequency is 48 MHz */
+		u32 pts = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;
+
+		data[1] |= UVC_STREAM_PTS;
+		put_unaligned_le32(pts, &data[pos]);
+		pos += 4;
+	}
+
+	if (cdev->gadget->ops->get_frame) {
+		u32 sof, stc;
+
+		sof = usb_gadget_frame_number(cdev->gadget);
+		ktime_get_ts64(&ts);
+		stc = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;
+
+		data[1] |= UVC_STREAM_SCR;
+		put_unaligned_le32(stc, &data[pos]);
+		put_unaligned_le16(sof, &data[pos+4]);
+		pos += 6;
+	}
+
+	data[0] = pos;
+
+	if (buf->bytesused - video->queue.buf_used <= len - pos)
+		data[1] |= UVC_STREAM_EOF;
+
+	return pos;
+}
+
+static int
+uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf,
+		u8 *data, int len)
+{
+	struct uvc_video_queue *queue = &video->queue;
+	unsigned int nbytes;
+	void *mem;
+
+	/* Copy video data to the USB buffer. */
+	mem = buf->mem + queue->buf_used;
+	nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
+
+	memcpy(data, mem, nbytes);
+	queue->buf_used += nbytes;
+
+	return nbytes;
+}
+
+static void
+uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
+		struct uvc_buffer *buf)
+{
+	void *mem = req->buf;
+	struct uvc_request *ureq = req->context;
+	int len = video->req_size;
+	int ret;
+
+	/* Add a header at the beginning of the payload. */
+	if (video->payload_size == 0) {
+		ret = uvc_video_encode_header(video, buf, mem, len);
+		video->payload_size += ret;
+		mem += ret;
+		len -= ret;
+	}
+
+	/* Process video data. */
+	len = min((int)(video->max_payload_size - video->payload_size), len);
+	ret = uvc_video_encode_data(video, buf, mem, len);
+
+	video->payload_size += ret;
+	len -= ret;
+
+	req->length = video->req_size - len;
+	req->zero = video->payload_size == video->max_payload_size;
+
+	if (buf->bytesused == video->queue.buf_used) {
+		video->queue.buf_used = 0;
+		buf->state = UVC_BUF_STATE_DONE;
+		list_del(&buf->queue);
+		video->fid ^= UVC_STREAM_FID;
+		ureq->last_buf = buf;
+
+		video->payload_size = 0;
+	}
+
+	if (video->payload_size == video->max_payload_size ||
+	    video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE ||
+	    buf->bytesused == video->queue.buf_used)
+		video->payload_size = 0;
+}
+
+static void
+uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
+		struct uvc_buffer *buf)
+{
+	unsigned int pending = buf->bytesused - video->queue.buf_used;
+	struct uvc_request *ureq = req->context;
+	struct scatterlist *sg, *iter;
+	unsigned int len = video->req_size;
+	unsigned int sg_left, part = 0;
+	unsigned int i;
+	int header_len;
+
+	sg = ureq->sgt.sgl;
+	sg_init_table(sg, ureq->sgt.nents);
+
+	/* Init the header. */
+	header_len = uvc_video_encode_header(video, buf, ureq->header,
+				      video->req_size);
+	sg_set_buf(sg, ureq->header, header_len);
+	len -= header_len;
+
+	if (pending <= len)
+		len = pending;
+
+	req->length = (len == pending) ?
+		len + header_len : 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 || !buf->sg->length)
+			break;
+
+		sg_left = buf->sg->length - 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 - header_len;
+
+	if (buf->bytesused == video->queue.buf_used || !buf->sg ||
+			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {
+		video->queue.buf_used = 0;
+		buf->state = UVC_BUF_STATE_DONE;
+		buf->offset = 0;
+		list_del(&buf->queue);
+		video->fid ^= UVC_STREAM_FID;
+		ureq->last_buf = buf;
+	}
+}
+
+static void
+uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
+		struct uvc_buffer *buf)
+{
+	void *mem = req->buf;
+	struct uvc_request *ureq = req->context;
+	int len = video->req_size;
+	int ret;
+
+	/* Add the header. */
+	ret = uvc_video_encode_header(video, buf, mem, len);
+	mem += ret;
+	len -= ret;
+
+	/* Process video data. */
+	ret = uvc_video_encode_data(video, buf, mem, len);
+	len -= ret;
+
+	req->length = video->req_size - len;
+
+	if (buf->bytesused == video->queue.buf_used ||
+			video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) {
+		video->queue.buf_used = 0;
+		buf->state = UVC_BUF_STATE_DONE;
+		list_del(&buf->queue);
+		video->fid ^= UVC_STREAM_FID;
+		ureq->last_buf = buf;
+	}
+}
+
+/* --------------------------------------------------------------------------
+ * Request handling
+ */
+
+static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
+{
+	int ret;
+
+	ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
+	if (ret < 0) {
+		uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
+			 ret);
+
+		/* If the endpoint is disabled the descriptor may be NULL. */
+		if (video->ep->desc) {
+			/* Isochronous endpoints can't be halted. */
+			if (usb_endpoint_xfer_bulk(video->ep->desc))
+				usb_ep_set_halt(video->ep);
+		}
+	}
+
+	return ret;
+}
+
+static void
+uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct uvc_request *ureq = req->context;
+	struct uvc_video *video = ureq->video;
+	struct uvc_video_queue *queue = &video->queue;
+	struct uvc_device *uvc = video->uvc;
+	unsigned long flags;
+
+	switch (req->status) {
+	case 0:
+		break;
+
+	case -EXDEV:
+		uvcg_dbg(&video->uvc->func, "VS request missed xfer.\n");
+		queue->flags |= UVC_QUEUE_DROP_INCOMPLETE;
+		break;
+
+	case -ESHUTDOWN:	/* disconnect from host. */
+		uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
+		uvcg_queue_cancel(queue, 1);
+		break;
+
+	default:
+		uvcg_warn(&video->uvc->func,
+			  "VS request completed with status %d.\n",
+			  req->status);
+		uvcg_queue_cancel(queue, 0);
+	}
+
+	if (ureq->last_buf) {
+		uvcg_complete_buffer(&video->queue, ureq->last_buf);
+		ureq->last_buf = NULL;
+	}
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	list_add_tail(&req->list, &video->req_free);
+	spin_unlock_irqrestore(&video->req_lock, flags);
+
+	if (uvc->state == UVC_STATE_STREAMING)
+		queue_work(video->async_wq, &video->pump);
+}
+
+static int
+uvc_video_free_requests(struct uvc_video *video)
+{
+	unsigned int i;
+
+	if (video->ureq) {
+		for (i = 0; i < video->uvc_num_requests; ++i) {
+			sg_free_table(&video->ureq[i].sgt);
+
+			if (video->ureq[i].req) {
+				usb_ep_free_request(video->ep, video->ureq[i].req);
+				video->ureq[i].req = NULL;
+			}
+
+			if (video->ureq[i].req_buffer) {
+				kfree(video->ureq[i].req_buffer);
+				video->ureq[i].req_buffer = NULL;
+			}
+		}
+
+		kfree(video->ureq);
+		video->ureq = NULL;
+	}
+
+	INIT_LIST_HEAD(&video->req_free);
+	video->req_size = 0;
+	return 0;
+}
+
+static int
+uvc_video_alloc_requests(struct uvc_video *video)
+{
+	unsigned int req_size;
+	unsigned int i;
+	int ret = -ENOMEM;
+
+	BUG_ON(video->req_size);
+
+	req_size = video->ep->maxpacket
+		 * max_t(unsigned int, video->ep->maxburst, 1)
+		 * (video->ep->mult);
+
+	video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL);
+	if (video->ureq == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < video->uvc_num_requests; ++i) {
+		video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL);
+		if (video->ureq[i].req_buffer == NULL)
+			goto error;
+
+		video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL);
+		if (video->ureq[i].req == NULL)
+			goto error;
+
+		video->ureq[i].req->buf = video->ureq[i].req_buffer;
+		video->ureq[i].req->length = 0;
+		video->ureq[i].req->complete = uvc_video_complete;
+		video->ureq[i].req->context = &video->ureq[i];
+		video->ureq[i].video = video;
+		video->ureq[i].last_buf = NULL;
+
+		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 - UVCG_REQUEST_HEADER_LEN,
+					    PAGE_SIZE) + 2, GFP_KERNEL);
+	}
+
+	video->req_size = req_size;
+
+	return 0;
+
+error:
+	uvc_video_free_requests(video);
+	return ret;
+}
+
+/* --------------------------------------------------------------------------
+ * Video streaming
+ */
+
+/*
+ * uvcg_video_pump - Pump video data into the USB requests
+ *
+ * This function fills the available USB requests (listed in req_free) with
+ * video data from the queued buffers.
+ */
+static void uvcg_video_pump(struct work_struct *work)
+{
+	struct uvc_video *video = container_of(work, struct uvc_video, pump);
+	struct uvc_video_queue *queue = &video->queue;
+	struct usb_request *req = NULL;
+	struct uvc_buffer *buf;
+	unsigned long flags;
+	int ret;
+	bool buf_int;
+	/* video->max_payload_size is only set when using bulk transfer */
+	bool is_bulk = video->max_payload_size;
+
+	while (video->ep->enabled) {
+		/*
+		 * Retrieve the first available USB request, protected by the
+		 * request lock.
+		 */
+		spin_lock_irqsave(&video->req_lock, flags);
+		if (list_empty(&video->req_free)) {
+			spin_unlock_irqrestore(&video->req_lock, flags);
+			return;
+		}
+		req = list_first_entry(&video->req_free, struct usb_request,
+					list);
+		list_del(&req->list);
+		spin_unlock_irqrestore(&video->req_lock, flags);
+
+		/*
+		 * Retrieve the first available video buffer and fill the
+		 * request, protected by the video queue irqlock.
+		 */
+		spin_lock_irqsave(&queue->irqlock, flags);
+		buf = uvcg_queue_head(queue);
+
+		if (buf != NULL) {
+			video->encode(req, video, buf);
+			/* Always interrupt for the last request of a video buffer */
+			buf_int = buf->state == UVC_BUF_STATE_DONE;
+		} else if (!(queue->flags & UVC_QUEUE_DISCONNECTED) && !is_bulk) {
+			/*
+			 * No video buffer available; the queue is still connected and
+			 * we're traferring over ISOC. Queue a 0 length request to
+			 * prevent missed ISOC transfers.
+			 */
+			req->length = 0;
+			buf_int = false;
+		} else {
+			/*
+			 * Either queue has been disconnected or no video buffer
+			 * available to bulk transfer. Either way, stop processing
+			 * further.
+			 */
+			spin_unlock_irqrestore(&queue->irqlock, flags);
+			break;
+		}
+
+		/*
+		 * With usb3 we have more requests. This will decrease the
+		 * interrupt load to a quarter but also catches the corner
+		 * cases, which needs to be handled.
+		 */
+		if (list_empty(&video->req_free) || buf_int ||
+		    !(video->req_int_count %
+		       DIV_ROUND_UP(video->uvc_num_requests, 4))) {
+			video->req_int_count = 0;
+			req->no_interrupt = 0;
+		} else {
+			req->no_interrupt = 1;
+		}
+
+		/* Queue the USB request */
+		ret = uvcg_video_ep_queue(video, req);
+		spin_unlock_irqrestore(&queue->irqlock, flags);
+
+		if (ret < 0) {
+			uvcg_queue_cancel(queue, 0);
+			break;
+		}
+
+		/* Endpoint now owns the request */
+		req = NULL;
+		video->req_int_count++;
+	}
+
+	if (!req)
+		return;
+
+	spin_lock_irqsave(&video->req_lock, flags);
+	list_add_tail(&req->list, &video->req_free);
+	spin_unlock_irqrestore(&video->req_lock, flags);
+	return;
+}
+
+/*
+ * Enable or disable the video stream.
+ */
+int uvcg_video_enable(struct uvc_video *video, int enable)
+{
+	unsigned int i;
+	int ret;
+
+	if (video->ep == NULL) {
+		uvcg_info(&video->uvc->func,
+			  "Video enable failed, device is uninitialized.\n");
+		return -ENODEV;
+	}
+
+	if (!enable) {
+		cancel_work_sync(&video->pump);
+		uvcg_queue_cancel(&video->queue, 0);
+
+		for (i = 0; i < video->uvc_num_requests; ++i)
+			if (video->ureq && video->ureq[i].req)
+				usb_ep_dequeue(video->ep, video->ureq[i].req);
+
+		uvc_video_free_requests(video);
+		uvcg_queue_enable(&video->queue, 0);
+		return 0;
+	}
+
+	if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0)
+		return ret;
+
+	if ((ret = uvc_video_alloc_requests(video)) < 0)
+		return ret;
+
+	if (video->max_payload_size) {
+		video->encode = uvc_video_encode_bulk;
+		video->payload_size = 0;
+	} else
+		video->encode = video->queue.use_sg ?
+			uvc_video_encode_isoc_sg : uvc_video_encode_isoc;
+
+	video->req_int_count = 0;
+
+	queue_work(video->async_wq, &video->pump);
+
+	return ret;
+}
+
+/*
+ * Initialize the UVC video stream.
+ */
+int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
+{
+	INIT_LIST_HEAD(&video->req_free);
+	spin_lock_init(&video->req_lock);
+	INIT_WORK(&video->pump, uvcg_video_pump);
+
+	/* Allocate a work queue for asynchronous video pump handler. */
+	video->async_wq = alloc_workqueue("uvcgadget", WQ_UNBOUND | WQ_HIGHPRI, 0);
+	if (!video->async_wq)
+		return -EINVAL;
+
+	video->uvc = uvc;
+	video->fcc = V4L2_PIX_FMT_YUYV;
+	video->bpp = 16;
+	video->width = 320;
+	video->height = 240;
+	video->imagesize = 320 * 240 * 2;
+
+	/* Initialize the video buffers queue. */
+	uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent,
+			V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex);
+	return 0;
+}