summaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/function/uvc_queue.c
blob: d25edc3d2174e14abfaf9cb33a13258d8c438d60 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
// SPDX-License-Identifier: GPL-2.0+
/*
 *	uvc_queue.c  --  USB Video Class driver - Buffers management
 *
 *	Copyright (C) 2005-2010
 *	    Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 */

#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>

#include <media/v4l2-common.h>
#include <media/videobuf2-dma-sg.h>
#include <media/videobuf2-vmalloc.h>

#include "uvc.h"

/* ------------------------------------------------------------------------
 * Video buffers queue management.
 *
 * Video queues is initialized by uvcg_queue_init(). The function performs
 * basic initialization of the uvc_video_queue struct and never fails.
 *
 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
 * the videobuf2 queue operations by serializing calls to videobuf2 and a
 * spinlock to protect the IRQ queue that holds the buffers to be processed by
 * the driver.
 */

/* -----------------------------------------------------------------------------
 * videobuf2 queue operations
 */

static int uvc_queue_setup(struct vb2_queue *vq,
			   unsigned int *nbuffers, unsigned int *nplanes,
			   unsigned int sizes[], struct device *alloc_devs[])
{
	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
	struct uvc_video *video = container_of(queue, struct uvc_video, queue);
	struct usb_composite_dev *cdev = video->uvc->func.config->cdev;

	if (*nbuffers > UVC_MAX_VIDEO_BUFFERS)
		*nbuffers = UVC_MAX_VIDEO_BUFFERS;

	*nplanes = 1;

	sizes[0] = video->imagesize;

	if (cdev->gadget->speed < USB_SPEED_SUPER)
		video->uvc_num_requests = 4;
	else
		video->uvc_num_requests = 64;

	return 0;
}

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);

	if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
	    vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
		uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
		return -EINVAL;
	}

	if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
		return -ENODEV;

	buf->state = UVC_BUF_STATE_QUEUED;
	if (queue->use_sg) {
		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;
	else
		buf->bytesused = vb2_get_plane_payload(vb, 0);

	return 0;
}

static void uvc_buffer_queue(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);
	unsigned long flags;

	spin_lock_irqsave(&queue->irqlock, flags);

	if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
		list_add_tail(&buf->queue, &queue->irqqueue);
	} else {
		/* If the device is disconnected return the buffer to userspace
		 * directly. The next QBUF call will fail with -ENODEV.
		 */
		buf->state = UVC_BUF_STATE_ERROR;
		vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
	}

	spin_unlock_irqrestore(&queue->irqlock, flags);
}

static const struct vb2_ops uvc_queue_qops = {
	.queue_setup = uvc_queue_setup,
	.buf_prepare = uvc_buffer_prepare,
	.buf_queue = uvc_buffer_queue,
	.wait_prepare = vb2_ops_wait_prepare,
	.wait_finish = vb2_ops_wait_finish,
};

int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, 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;
	queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
	queue->queue.drv_priv = queue;
	queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
	queue->queue.ops = &uvc_queue_qops;
	queue->queue.lock = lock;
	if (cdev->gadget->sg_supported) {
		queue->queue.mem_ops = &vb2_dma_sg_memops;
		queue->use_sg = 1;
	} else {
		queue->queue.mem_ops = &vb2_vmalloc_memops;
	}

	queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY
				     | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
	queue->queue.dev = dev;

	ret = vb2_queue_init(&queue->queue);
	if (ret)
		return ret;

	spin_lock_init(&queue->irqlock);
	INIT_LIST_HEAD(&queue->irqqueue);
	queue->flags = 0;

	return 0;
}

/*
 * Free the video buffers.
 */
void uvcg_free_buffers(struct uvc_video_queue *queue)
{
	vb2_queue_release(&queue->queue);
}

/*
 * Allocate the video buffers.
 */
int uvcg_alloc_buffers(struct uvc_video_queue *queue,
			      struct v4l2_requestbuffers *rb)
{
	int ret;

	ret = vb2_reqbufs(&queue->queue, rb);

	return ret ? ret : rb->count;
}

int uvcg_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
{
	return vb2_querybuf(&queue->queue, buf);
}

int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
{
	return vb2_qbuf(&queue->queue, NULL, buf);
}

/*
 * Dequeue a video buffer. If nonblocking is false, block until a buffer is
 * available.
 */
int uvcg_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
			int nonblocking)
{
	return vb2_dqbuf(&queue->queue, buf, nonblocking);
}

/*
 * Poll the video queue.
 *
 * This function implements video queue polling and is intended to be used by
 * the device poll handler.
 */
__poll_t uvcg_queue_poll(struct uvc_video_queue *queue, struct file *file,
			     poll_table *wait)
{
	return vb2_poll(&queue->queue, file, wait);
}

int uvcg_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
{
	return vb2_mmap(&queue->queue, vma);
}

#ifndef CONFIG_MMU
/*
 * Get unmapped area.
 *
 * NO-MMU arch need this function to make mmap() work correctly.
 */
unsigned long uvcg_queue_get_unmapped_area(struct uvc_video_queue *queue,
					   unsigned long pgoff)
{
	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
}
#endif

/*
 * Cancel the video buffers queue.
 *
 * Cancelling the queue marks all buffers on the irq queue as erroneous,
 * wakes them up and removes them from the queue.
 *
 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
 * fail with -ENODEV.
 *
 * This function acquires the irq spinlock and can be called from interrupt
 * context.
 */
void uvcg_queue_cancel(struct uvc_video_queue *queue, int disconnect)
{
	struct uvc_buffer *buf;
	unsigned long flags;

	spin_lock_irqsave(&queue->irqlock, flags);
	while (!list_empty(&queue->irqqueue)) {
		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
				       queue);
		list_del(&buf->queue);
		buf->state = UVC_BUF_STATE_ERROR;
		vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
	}
	queue->buf_used = 0;

	/* This must be protected by the irqlock spinlock to avoid race
	 * conditions between uvc_queue_buffer and the disconnection event that
	 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
	 * blindly replace this logic by checking for the UVC_DEV_DISCONNECTED
	 * state outside the queue code.
	 */
	if (disconnect)
		queue->flags |= UVC_QUEUE_DISCONNECTED;
	spin_unlock_irqrestore(&queue->irqlock, flags);
}

/*
 * Enable or disable the video buffers queue.
 *
 * The queue must be enabled before starting video acquisition and must be
 * disabled after stopping it. This ensures that the video buffers queue
 * state can be properly initialized before buffers are accessed from the
 * interrupt handler.
 *
 * Enabling the video queue initializes parameters (such as sequence number,
 * sync pattern, ...). If the queue is already enabled, return -EBUSY.
 *
 * Disabling the video queue cancels the queue and removes all buffers from
 * the main queue.
 *
 * This function can't be called from interrupt context. Use
 * uvcg_queue_cancel() instead.
 */
int uvcg_queue_enable(struct uvc_video_queue *queue, int enable)
{
	unsigned long flags;
	int ret = 0;

	if (enable) {
		ret = vb2_streamon(&queue->queue, queue->queue.type);
		if (ret < 0)
			return ret;

		queue->sequence = 0;
		queue->buf_used = 0;
	} else {
		ret = vb2_streamoff(&queue->queue, queue->queue.type);
		if (ret < 0)
			return ret;

		spin_lock_irqsave(&queue->irqlock, flags);
		INIT_LIST_HEAD(&queue->irqqueue);

		/*
		 * FIXME: We need to clear the DISCONNECTED flag to ensure that
		 * applications will be able to queue buffers for the next
		 * streaming run. However, clearing it here doesn't guarantee
		 * that the device will be reconnected in the meantime.
		 */
		queue->flags &= ~UVC_QUEUE_DISCONNECTED;
		spin_unlock_irqrestore(&queue->irqlock, flags);
	}

	return ret;
}

/* called with &queue_irqlock held.. */
void uvcg_complete_buffer(struct uvc_video_queue *queue,
					  struct uvc_buffer *buf)
{
	if ((queue->flags & UVC_QUEUE_DROP_INCOMPLETE) &&
	     buf->length != buf->bytesused) {
		buf->state = UVC_BUF_STATE_QUEUED;
		vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0);
		return;
	}

	buf->buf.field = V4L2_FIELD_NONE;
	buf->buf.sequence = queue->sequence++;
	buf->buf.vb2_buf.timestamp = ktime_get_ns();

	vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused);
	vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
}

struct uvc_buffer *uvcg_queue_head(struct uvc_video_queue *queue)
{
	struct uvc_buffer *buf = NULL;

	if (!list_empty(&queue->irqqueue))
		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
				       queue);

	return buf;
}