Commit | Line | Data |
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cdda479f LP |
1 | /* |
2 | * uvc_video.c -- USB Video Class Gadget driver | |
3 | * | |
4 | * Copyright (C) 2009-2010 | |
5 | * Laurent Pinchart (laurent.pinchart@ideasonboard.com) | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
cdda479f LP |
11 | */ |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/usb/ch9.h> | |
17 | #include <linux/usb/gadget.h> | |
3a83c16e | 18 | #include <linux/usb/video.h> |
cdda479f LP |
19 | |
20 | #include <media/v4l2-dev.h> | |
21 | ||
22 | #include "uvc.h" | |
23 | #include "uvc_queue.h" | |
70685711 | 24 | #include "uvc_video.h" |
cdda479f LP |
25 | |
26 | /* -------------------------------------------------------------------------- | |
27 | * Video codecs | |
28 | */ | |
29 | ||
30 | static int | |
31 | uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf, | |
32 | u8 *data, int len) | |
33 | { | |
34 | data[0] = 2; | |
35 | data[1] = UVC_STREAM_EOH | video->fid; | |
36 | ||
d6925225 | 37 | if (buf->bytesused - video->queue.buf_used <= len - 2) |
cdda479f LP |
38 | data[1] |= UVC_STREAM_EOF; |
39 | ||
40 | return 2; | |
41 | } | |
42 | ||
43 | static int | |
44 | uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf, | |
45 | u8 *data, int len) | |
46 | { | |
47 | struct uvc_video_queue *queue = &video->queue; | |
48 | unsigned int nbytes; | |
49 | void *mem; | |
50 | ||
51 | /* Copy video data to the USB buffer. */ | |
d6925225 BS |
52 | mem = buf->mem + queue->buf_used; |
53 | nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used); | |
cdda479f LP |
54 | |
55 | memcpy(data, mem, nbytes); | |
56 | queue->buf_used += nbytes; | |
57 | ||
58 | return nbytes; | |
59 | } | |
60 | ||
61 | static void | |
62 | uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video, | |
63 | struct uvc_buffer *buf) | |
64 | { | |
65 | void *mem = req->buf; | |
66 | int len = video->req_size; | |
67 | int ret; | |
68 | ||
69 | /* Add a header at the beginning of the payload. */ | |
70 | if (video->payload_size == 0) { | |
71 | ret = uvc_video_encode_header(video, buf, mem, len); | |
72 | video->payload_size += ret; | |
73 | mem += ret; | |
74 | len -= ret; | |
75 | } | |
76 | ||
77 | /* Process video data. */ | |
78 | len = min((int)(video->max_payload_size - video->payload_size), len); | |
79 | ret = uvc_video_encode_data(video, buf, mem, len); | |
80 | ||
81 | video->payload_size += ret; | |
82 | len -= ret; | |
83 | ||
84 | req->length = video->req_size - len; | |
85 | req->zero = video->payload_size == video->max_payload_size; | |
86 | ||
d6925225 | 87 | if (buf->bytesused == video->queue.buf_used) { |
cdda479f LP |
88 | video->queue.buf_used = 0; |
89 | buf->state = UVC_BUF_STATE_DONE; | |
7ea95b11 | 90 | uvcg_queue_next_buffer(&video->queue, buf); |
cdda479f LP |
91 | video->fid ^= UVC_STREAM_FID; |
92 | ||
93 | video->payload_size = 0; | |
94 | } | |
95 | ||
96 | if (video->payload_size == video->max_payload_size || | |
d6925225 | 97 | buf->bytesused == video->queue.buf_used) |
cdda479f LP |
98 | video->payload_size = 0; |
99 | } | |
100 | ||
101 | static void | |
102 | uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, | |
103 | struct uvc_buffer *buf) | |
104 | { | |
105 | void *mem = req->buf; | |
106 | int len = video->req_size; | |
107 | int ret; | |
108 | ||
109 | /* Add the header. */ | |
110 | ret = uvc_video_encode_header(video, buf, mem, len); | |
111 | mem += ret; | |
112 | len -= ret; | |
113 | ||
114 | /* Process video data. */ | |
115 | ret = uvc_video_encode_data(video, buf, mem, len); | |
116 | len -= ret; | |
117 | ||
118 | req->length = video->req_size - len; | |
119 | ||
d6925225 | 120 | if (buf->bytesused == video->queue.buf_used) { |
cdda479f LP |
121 | video->queue.buf_used = 0; |
122 | buf->state = UVC_BUF_STATE_DONE; | |
7ea95b11 | 123 | uvcg_queue_next_buffer(&video->queue, buf); |
cdda479f LP |
124 | video->fid ^= UVC_STREAM_FID; |
125 | } | |
126 | } | |
127 | ||
128 | /* -------------------------------------------------------------------------- | |
129 | * Request handling | |
130 | */ | |
131 | ||
132 | /* | |
133 | * I somehow feel that synchronisation won't be easy to achieve here. We have | |
134 | * three events that control USB requests submission: | |
135 | * | |
136 | * - USB request completion: the completion handler will resubmit the request | |
137 | * if a video buffer is available. | |
138 | * | |
139 | * - USB interface setting selection: in response to a SET_INTERFACE request, | |
140 | * the handler will start streaming if a video buffer is available and if | |
141 | * video is not currently streaming. | |
142 | * | |
143 | * - V4L2 buffer queueing: the driver will start streaming if video is not | |
144 | * currently streaming. | |
145 | * | |
146 | * Race conditions between those 3 events might lead to deadlocks or other | |
147 | * nasty side effects. | |
148 | * | |
149 | * The "video currently streaming" condition can't be detected by the irqqueue | |
150 | * being empty, as a request can still be in flight. A separate "queue paused" | |
151 | * flag is thus needed. | |
152 | * | |
153 | * The paused flag will be set when we try to retrieve the irqqueue head if the | |
154 | * queue is empty, and cleared when we queue a buffer. | |
155 | * | |
156 | * The USB request completion handler will get the buffer at the irqqueue head | |
157 | * under protection of the queue spinlock. If the queue is empty, the streaming | |
158 | * paused flag will be set. Right after releasing the spinlock a userspace | |
159 | * application can queue a buffer. The flag will then cleared, and the ioctl | |
160 | * handler will restart the video stream. | |
161 | */ | |
162 | static void | |
163 | uvc_video_complete(struct usb_ep *ep, struct usb_request *req) | |
164 | { | |
165 | struct uvc_video *video = req->context; | |
d6925225 | 166 | struct uvc_video_queue *queue = &video->queue; |
cdda479f LP |
167 | struct uvc_buffer *buf; |
168 | unsigned long flags; | |
169 | int ret; | |
170 | ||
171 | switch (req->status) { | |
172 | case 0: | |
173 | break; | |
174 | ||
d6925225 | 175 | case -ESHUTDOWN: /* disconnect from host. */ |
6bc17375 | 176 | printk(KERN_DEBUG "VS request cancelled.\n"); |
7ea95b11 | 177 | uvcg_queue_cancel(queue, 1); |
cdda479f LP |
178 | goto requeue; |
179 | ||
180 | default: | |
181 | printk(KERN_INFO "VS request completed with status %d.\n", | |
182 | req->status); | |
7ea95b11 | 183 | uvcg_queue_cancel(queue, 0); |
cdda479f LP |
184 | goto requeue; |
185 | } | |
186 | ||
187 | spin_lock_irqsave(&video->queue.irqlock, flags); | |
7ea95b11 | 188 | buf = uvcg_queue_head(&video->queue); |
cdda479f LP |
189 | if (buf == NULL) { |
190 | spin_unlock_irqrestore(&video->queue.irqlock, flags); | |
191 | goto requeue; | |
192 | } | |
193 | ||
194 | video->encode(req, video, buf); | |
195 | ||
196 | if ((ret = usb_ep_queue(ep, req, GFP_ATOMIC)) < 0) { | |
197 | printk(KERN_INFO "Failed to queue request (%d).\n", ret); | |
198 | usb_ep_set_halt(ep); | |
199 | spin_unlock_irqrestore(&video->queue.irqlock, flags); | |
7ea95b11 | 200 | uvcg_queue_cancel(queue, 0); |
cdda479f LP |
201 | goto requeue; |
202 | } | |
203 | spin_unlock_irqrestore(&video->queue.irqlock, flags); | |
204 | ||
205 | return; | |
206 | ||
207 | requeue: | |
208 | spin_lock_irqsave(&video->req_lock, flags); | |
209 | list_add_tail(&req->list, &video->req_free); | |
210 | spin_unlock_irqrestore(&video->req_lock, flags); | |
211 | } | |
212 | ||
213 | static int | |
214 | uvc_video_free_requests(struct uvc_video *video) | |
215 | { | |
216 | unsigned int i; | |
217 | ||
218 | for (i = 0; i < UVC_NUM_REQUESTS; ++i) { | |
219 | if (video->req[i]) { | |
220 | usb_ep_free_request(video->ep, video->req[i]); | |
221 | video->req[i] = NULL; | |
222 | } | |
223 | ||
224 | if (video->req_buffer[i]) { | |
225 | kfree(video->req_buffer[i]); | |
226 | video->req_buffer[i] = NULL; | |
227 | } | |
228 | } | |
229 | ||
230 | INIT_LIST_HEAD(&video->req_free); | |
231 | video->req_size = 0; | |
232 | return 0; | |
233 | } | |
234 | ||
235 | static int | |
236 | uvc_video_alloc_requests(struct uvc_video *video) | |
237 | { | |
326b0e61 | 238 | unsigned int req_size; |
cdda479f LP |
239 | unsigned int i; |
240 | int ret = -ENOMEM; | |
241 | ||
242 | BUG_ON(video->req_size); | |
243 | ||
326b0e61 BS |
244 | req_size = video->ep->maxpacket |
245 | * max_t(unsigned int, video->ep->maxburst, 1) | |
246 | * (video->ep->mult + 1); | |
247 | ||
cdda479f | 248 | for (i = 0; i < UVC_NUM_REQUESTS; ++i) { |
326b0e61 | 249 | video->req_buffer[i] = kmalloc(req_size, GFP_KERNEL); |
cdda479f LP |
250 | if (video->req_buffer[i] == NULL) |
251 | goto error; | |
252 | ||
253 | video->req[i] = usb_ep_alloc_request(video->ep, GFP_KERNEL); | |
254 | if (video->req[i] == NULL) | |
255 | goto error; | |
256 | ||
257 | video->req[i]->buf = video->req_buffer[i]; | |
258 | video->req[i]->length = 0; | |
cdda479f LP |
259 | video->req[i]->complete = uvc_video_complete; |
260 | video->req[i]->context = video; | |
261 | ||
262 | list_add_tail(&video->req[i]->list, &video->req_free); | |
263 | } | |
264 | ||
326b0e61 BS |
265 | video->req_size = req_size; |
266 | ||
cdda479f LP |
267 | return 0; |
268 | ||
269 | error: | |
270 | uvc_video_free_requests(video); | |
271 | return ret; | |
272 | } | |
273 | ||
274 | /* -------------------------------------------------------------------------- | |
275 | * Video streaming | |
276 | */ | |
277 | ||
278 | /* | |
7ea95b11 | 279 | * uvcg_video_pump - Pump video data into the USB requests |
cdda479f LP |
280 | * |
281 | * This function fills the available USB requests (listed in req_free) with | |
282 | * video data from the queued buffers. | |
283 | */ | |
3a83c16e | 284 | int uvcg_video_pump(struct uvc_video *video) |
cdda479f | 285 | { |
bd52b813 | 286 | struct uvc_video_queue *queue = &video->queue; |
cdda479f LP |
287 | struct usb_request *req; |
288 | struct uvc_buffer *buf; | |
289 | unsigned long flags; | |
290 | int ret; | |
291 | ||
7ea95b11 | 292 | /* FIXME TODO Race between uvcg_video_pump and requests completion |
cdda479f LP |
293 | * handler ??? |
294 | */ | |
295 | ||
296 | while (1) { | |
297 | /* Retrieve the first available USB request, protected by the | |
298 | * request lock. | |
299 | */ | |
300 | spin_lock_irqsave(&video->req_lock, flags); | |
301 | if (list_empty(&video->req_free)) { | |
302 | spin_unlock_irqrestore(&video->req_lock, flags); | |
303 | return 0; | |
304 | } | |
305 | req = list_first_entry(&video->req_free, struct usb_request, | |
306 | list); | |
307 | list_del(&req->list); | |
308 | spin_unlock_irqrestore(&video->req_lock, flags); | |
309 | ||
310 | /* Retrieve the first available video buffer and fill the | |
311 | * request, protected by the video queue irqlock. | |
312 | */ | |
6dd5b021 LP |
313 | spin_lock_irqsave(&queue->irqlock, flags); |
314 | buf = uvcg_queue_head(queue); | |
cdda479f | 315 | if (buf == NULL) { |
6dd5b021 | 316 | spin_unlock_irqrestore(&queue->irqlock, flags); |
cdda479f LP |
317 | break; |
318 | } | |
319 | ||
320 | video->encode(req, video, buf); | |
321 | ||
322 | /* Queue the USB request */ | |
6854bcdc CR |
323 | ret = usb_ep_queue(video->ep, req, GFP_ATOMIC); |
324 | if (ret < 0) { | |
cdda479f LP |
325 | printk(KERN_INFO "Failed to queue request (%d)\n", ret); |
326 | usb_ep_set_halt(video->ep); | |
6dd5b021 | 327 | spin_unlock_irqrestore(&queue->irqlock, flags); |
7ea95b11 | 328 | uvcg_queue_cancel(queue, 0); |
cdda479f LP |
329 | break; |
330 | } | |
6dd5b021 | 331 | spin_unlock_irqrestore(&queue->irqlock, flags); |
cdda479f LP |
332 | } |
333 | ||
334 | spin_lock_irqsave(&video->req_lock, flags); | |
335 | list_add_tail(&req->list, &video->req_free); | |
336 | spin_unlock_irqrestore(&video->req_lock, flags); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | /* | |
341 | * Enable or disable the video stream. | |
342 | */ | |
3a83c16e | 343 | int uvcg_video_enable(struct uvc_video *video, int enable) |
cdda479f LP |
344 | { |
345 | unsigned int i; | |
346 | int ret; | |
347 | ||
348 | if (video->ep == NULL) { | |
349 | printk(KERN_INFO "Video enable failed, device is " | |
350 | "uninitialized.\n"); | |
351 | return -ENODEV; | |
352 | } | |
353 | ||
354 | if (!enable) { | |
355 | for (i = 0; i < UVC_NUM_REQUESTS; ++i) | |
d7577b38 FB |
356 | if (video->req[i]) |
357 | usb_ep_dequeue(video->ep, video->req[i]); | |
cdda479f LP |
358 | |
359 | uvc_video_free_requests(video); | |
7ea95b11 | 360 | uvcg_queue_enable(&video->queue, 0); |
cdda479f LP |
361 | return 0; |
362 | } | |
363 | ||
7ea95b11 | 364 | if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) |
cdda479f LP |
365 | return ret; |
366 | ||
367 | if ((ret = uvc_video_alloc_requests(video)) < 0) | |
368 | return ret; | |
369 | ||
370 | if (video->max_payload_size) { | |
371 | video->encode = uvc_video_encode_bulk; | |
372 | video->payload_size = 0; | |
373 | } else | |
374 | video->encode = uvc_video_encode_isoc; | |
375 | ||
7ea95b11 | 376 | return uvcg_video_pump(video); |
cdda479f LP |
377 | } |
378 | ||
379 | /* | |
380 | * Initialize the UVC video stream. | |
381 | */ | |
3a83c16e | 382 | int uvcg_video_init(struct uvc_video *video) |
cdda479f LP |
383 | { |
384 | INIT_LIST_HEAD(&video->req_free); | |
385 | spin_lock_init(&video->req_lock); | |
386 | ||
387 | video->fcc = V4L2_PIX_FMT_YUYV; | |
388 | video->bpp = 16; | |
389 | video->width = 320; | |
390 | video->height = 240; | |
391 | video->imagesize = 320 * 240 * 2; | |
392 | ||
393 | /* Initialize the video buffers queue. */ | |
7ea95b11 | 394 | uvcg_queue_init(&video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT); |
cdda479f LP |
395 | return 0; |
396 | } | |
397 |