1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * STK1160 driver
4 *
5 * Copyright (C) 2012 Ezequiel Garcia
6 * <elezegarcia--a.t--gmail.com>
7 *
8 * Based on Easycap driver by R.M. Thomas
9 * Copyright (C) 2010 R.M. Thomas
10 * <rmthomas--a.t--sciolus.org>
11 */
12
13 #include <linux/module.h>
14 #include <linux/usb.h>
15 #include <linux/slab.h>
16 #include <linux/ratelimit.h>
17
18 #include "stk1160.h"
19
20 static unsigned int debug;
21 module_param(debug, int, 0644);
22 MODULE_PARM_DESC(debug, "enable debug messages");
23
print_err_status(struct stk1160 * dev,int packet,int status)24 static inline void print_err_status(struct stk1160 *dev,
25 int packet, int status)
26 {
27 char *errmsg = "Unknown";
28
29 switch (status) {
30 case -ENOENT:
31 errmsg = "unlinked synchronously";
32 break;
33 case -ECONNRESET:
34 errmsg = "unlinked asynchronously";
35 break;
36 case -ENOSR:
37 errmsg = "Buffer error (overrun)";
38 break;
39 case -EPIPE:
40 errmsg = "Stalled (device not responding)";
41 break;
42 case -EOVERFLOW:
43 errmsg = "Babble (bad cable?)";
44 break;
45 case -EPROTO:
46 errmsg = "Bit-stuff error (bad cable?)";
47 break;
48 case -EILSEQ:
49 errmsg = "CRC/Timeout (could be anything)";
50 break;
51 case -ETIME:
52 errmsg = "Device does not respond";
53 break;
54 }
55
56 if (packet < 0)
57 printk_ratelimited(KERN_WARNING "URB status %d [%s].\n",
58 status, errmsg);
59 else
60 printk_ratelimited(KERN_INFO "URB packet %d, status %d [%s].\n",
61 packet, status, errmsg);
62 }
63
64 static inline
stk1160_next_buffer(struct stk1160 * dev)65 struct stk1160_buffer *stk1160_next_buffer(struct stk1160 *dev)
66 {
67 struct stk1160_buffer *buf = NULL;
68 unsigned long flags = 0;
69
70 /* Current buffer must be NULL when this functions gets called */
71 WARN_ON(dev->isoc_ctl.buf);
72
73 spin_lock_irqsave(&dev->buf_lock, flags);
74 if (!list_empty(&dev->avail_bufs)) {
75 buf = list_first_entry(&dev->avail_bufs,
76 struct stk1160_buffer, list);
77 list_del(&buf->list);
78 }
79 spin_unlock_irqrestore(&dev->buf_lock, flags);
80
81 return buf;
82 }
83
84 static inline
stk1160_buffer_done(struct stk1160 * dev)85 void stk1160_buffer_done(struct stk1160 *dev)
86 {
87 struct stk1160_buffer *buf = dev->isoc_ctl.buf;
88
89 buf->vb.sequence = dev->sequence++;
90 buf->vb.field = V4L2_FIELD_INTERLACED;
91 buf->vb.vb2_buf.timestamp = ktime_get_ns();
92
93 vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->bytesused);
94 vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
95
96 dev->isoc_ctl.buf = NULL;
97 }
98
99 static inline
stk1160_copy_video(struct stk1160 * dev,u8 * src,int len)100 void stk1160_copy_video(struct stk1160 *dev, u8 *src, int len)
101 {
102 int linesdone, lineoff, lencopy;
103 int bytesperline = dev->width * 2;
104 struct stk1160_buffer *buf = dev->isoc_ctl.buf;
105 u8 *dst = buf->mem;
106 int remain;
107
108 /*
109 * TODO: These stk1160_dbg are very spammy!
110 * We should check why we are getting them.
111 *
112 * UPDATE: One of the reasons (the only one?) for getting these
113 * is incorrect standard (mismatch between expected and configured).
114 * So perhaps, we could add a counter for errors. When the counter
115 * reaches some value, we simply stop streaming.
116 */
117
118 len -= 4;
119 src += 4;
120
121 remain = len;
122
123 linesdone = buf->pos / bytesperline;
124 lineoff = buf->pos % bytesperline; /* offset in current line */
125
126 if (!buf->odd)
127 dst += bytesperline;
128
129 /* Multiply linesdone by two, to take account of the other field */
130 dst += linesdone * bytesperline * 2 + lineoff;
131
132 /* Copy the remaining of current line */
133 if (remain < (bytesperline - lineoff))
134 lencopy = remain;
135 else
136 lencopy = bytesperline - lineoff;
137
138 /*
139 * Check if we have enough space left in the buffer.
140 * In that case, we force loop exit after copy.
141 */
142 if (lencopy > buf->bytesused - buf->length) {
143 lencopy = buf->bytesused - buf->length;
144 remain = lencopy;
145 }
146
147 /* Check if the copy is done */
148 if (lencopy == 0 || remain == 0)
149 return;
150
151 /* Let the bug hunt begin! sanity checks! */
152 if (lencopy < 0) {
153 printk_ratelimited(KERN_DEBUG "copy skipped: negative lencopy\n");
154 return;
155 }
156
157 if ((unsigned long)dst + lencopy >
158 (unsigned long)buf->mem + buf->length) {
159 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
160 return;
161 }
162
163 memcpy(dst, src, lencopy);
164
165 buf->bytesused += lencopy;
166 buf->pos += lencopy;
167 remain -= lencopy;
168
169 /* Copy current field line by line, interlacing with the other field */
170 while (remain > 0) {
171
172 dst += lencopy + bytesperline;
173 src += lencopy;
174
175 /* Copy one line at a time */
176 if (remain < bytesperline)
177 lencopy = remain;
178 else
179 lencopy = bytesperline;
180
181 /*
182 * Check if we have enough space left in the buffer.
183 * In that case, we force loop exit after copy.
184 */
185 if (lencopy > buf->bytesused - buf->length) {
186 lencopy = buf->bytesused - buf->length;
187 remain = lencopy;
188 }
189
190 /* Check if the copy is done */
191 if (lencopy == 0 || remain == 0)
192 return;
193
194 if (lencopy < 0) {
195 printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
196 return;
197 }
198
199 if ((unsigned long)dst + lencopy >
200 (unsigned long)buf->mem + buf->length) {
201 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
202 return;
203 }
204
205 memcpy(dst, src, lencopy);
206 remain -= lencopy;
207
208 buf->bytesused += lencopy;
209 buf->pos += lencopy;
210 }
211 }
212
213 /*
214 * Controls the isoc copy of each urb packet
215 */
stk1160_process_isoc(struct stk1160 * dev,struct urb * urb)216 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
217 {
218 int i, len, status;
219 u8 *p;
220
221 if (!dev) {
222 stk1160_warn("%s called with null device\n", __func__);
223 return;
224 }
225
226 if (urb->status < 0) {
227 /* Print status and drop current packet (or field?) */
228 print_err_status(dev, -1, urb->status);
229 return;
230 }
231
232 for (i = 0; i < urb->number_of_packets; i++) {
233 status = urb->iso_frame_desc[i].status;
234 if (status < 0) {
235 print_err_status(dev, i, status);
236 continue;
237 }
238
239 /* Get packet actual length and pointer to data */
240 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
241 len = urb->iso_frame_desc[i].actual_length;
242
243 /* Empty packet */
244 if (len <= 4)
245 continue;
246
247 /*
248 * An 8-byte packet sequence means end of field.
249 * So if we don't have any packet, we start receiving one now
250 * and if we do have a packet, then we are done with it.
251 *
252 * These end of field packets are always 0xc0 or 0x80,
253 * but not always 8-byte long so we don't check packet length.
254 */
255 if (p[0] == 0xc0) {
256
257 /*
258 * If first byte is 0xc0 then we received
259 * second field, and frame has ended.
260 */
261 if (dev->isoc_ctl.buf != NULL)
262 stk1160_buffer_done(dev);
263
264 dev->isoc_ctl.buf = stk1160_next_buffer(dev);
265 if (dev->isoc_ctl.buf == NULL)
266 return;
267 }
268
269 /*
270 * If we don't have a buffer here, then it means we
271 * haven't found the start mark sequence.
272 */
273 if (dev->isoc_ctl.buf == NULL)
274 continue;
275
276 if (p[0] == 0xc0 || p[0] == 0x80) {
277
278 /* We set next packet parity and
279 * continue to get next one
280 */
281 dev->isoc_ctl.buf->odd = *p & 0x40;
282 dev->isoc_ctl.buf->pos = 0;
283 continue;
284 }
285
286 stk1160_copy_video(dev, p, len);
287 }
288 }
289
290
291 /*
292 * IRQ callback, called by URB callback
293 */
stk1160_isoc_irq(struct urb * urb)294 static void stk1160_isoc_irq(struct urb *urb)
295 {
296 int i, rc;
297 struct stk1160 *dev = urb->context;
298
299 switch (urb->status) {
300 case 0:
301 break;
302 case -ECONNRESET: /* kill */
303 case -ENOENT:
304 case -ESHUTDOWN:
305 /* TODO: check uvc driver: he frees the queue here */
306 return;
307 default:
308 stk1160_err("urb error! status %d\n", urb->status);
309 return;
310 }
311
312 stk1160_process_isoc(dev, urb);
313
314 /* Reset urb buffers */
315 for (i = 0; i < urb->number_of_packets; i++) {
316 urb->iso_frame_desc[i].status = 0;
317 urb->iso_frame_desc[i].actual_length = 0;
318 }
319
320 rc = usb_submit_urb(urb, GFP_ATOMIC);
321 if (rc)
322 stk1160_err("urb re-submit failed (%d)\n", rc);
323 }
324
325 /*
326 * Cancel urbs
327 * This function can't be called in atomic context
328 */
stk1160_cancel_isoc(struct stk1160 * dev)329 void stk1160_cancel_isoc(struct stk1160 *dev)
330 {
331 int i, num_bufs = dev->isoc_ctl.num_bufs;
332
333 /*
334 * This check is not necessary, but we add it
335 * to avoid a spurious debug message
336 */
337 if (!num_bufs)
338 return;
339
340 stk1160_dbg("killing %d urbs...\n", num_bufs);
341
342 for (i = 0; i < num_bufs; i++) {
343
344 /*
345 * To kill urbs we can't be in atomic context.
346 * We don't care for NULL pointer since
347 * usb_kill_urb allows it.
348 */
349 usb_kill_urb(dev->isoc_ctl.urb[i]);
350 }
351
352 stk1160_dbg("all urbs killed\n");
353 }
354
355 /*
356 * Releases urb and transfer buffers
357 * Obviusly, associated urb must be killed before releasing it.
358 */
stk1160_free_isoc(struct stk1160 * dev)359 void stk1160_free_isoc(struct stk1160 *dev)
360 {
361 struct urb *urb;
362 int i, num_bufs = dev->isoc_ctl.num_bufs;
363
364 stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
365
366 for (i = 0; i < num_bufs; i++) {
367
368 urb = dev->isoc_ctl.urb[i];
369 if (urb) {
370
371 if (dev->isoc_ctl.transfer_buffer[i]) {
372 #ifndef CONFIG_DMA_NONCOHERENT
373 usb_free_coherent(dev->udev,
374 urb->transfer_buffer_length,
375 dev->isoc_ctl.transfer_buffer[i],
376 urb->transfer_dma);
377 #else
378 kfree(dev->isoc_ctl.transfer_buffer[i]);
379 #endif
380 }
381 usb_free_urb(urb);
382 dev->isoc_ctl.urb[i] = NULL;
383 }
384 dev->isoc_ctl.transfer_buffer[i] = NULL;
385 }
386
387 kfree(dev->isoc_ctl.urb);
388 kfree(dev->isoc_ctl.transfer_buffer);
389
390 dev->isoc_ctl.urb = NULL;
391 dev->isoc_ctl.transfer_buffer = NULL;
392 dev->isoc_ctl.num_bufs = 0;
393
394 stk1160_dbg("all urb buffers freed\n");
395 }
396
397 /*
398 * Helper for cancelling and freeing urbs
399 * This function can't be called in atomic context
400 */
stk1160_uninit_isoc(struct stk1160 * dev)401 void stk1160_uninit_isoc(struct stk1160 *dev)
402 {
403 stk1160_cancel_isoc(dev);
404 stk1160_free_isoc(dev);
405 }
406
407 /*
408 * Allocate URBs
409 */
stk1160_alloc_isoc(struct stk1160 * dev)410 int stk1160_alloc_isoc(struct stk1160 *dev)
411 {
412 struct urb *urb;
413 int i, j, k, sb_size, max_packets, num_bufs;
414
415 /*
416 * It may be necessary to release isoc here,
417 * since isoc are only released on disconnection.
418 * (see new_pkt_size flag)
419 */
420 if (dev->isoc_ctl.num_bufs)
421 stk1160_uninit_isoc(dev);
422
423 stk1160_dbg("allocating urbs...\n");
424
425 num_bufs = STK1160_NUM_BUFS;
426 max_packets = STK1160_NUM_PACKETS;
427 sb_size = max_packets * dev->max_pkt_size;
428
429 dev->isoc_ctl.buf = NULL;
430 dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
431 dev->isoc_ctl.urb = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
432 if (!dev->isoc_ctl.urb) {
433 stk1160_err("out of memory for urb array\n");
434 return -ENOMEM;
435 }
436
437 dev->isoc_ctl.transfer_buffer = kcalloc(num_bufs, sizeof(void *),
438 GFP_KERNEL);
439 if (!dev->isoc_ctl.transfer_buffer) {
440 stk1160_err("out of memory for usb transfers\n");
441 kfree(dev->isoc_ctl.urb);
442 return -ENOMEM;
443 }
444
445 /* allocate urbs and transfer buffers */
446 for (i = 0; i < num_bufs; i++) {
447
448 urb = usb_alloc_urb(max_packets, GFP_KERNEL);
449 if (!urb)
450 goto free_i_bufs;
451 dev->isoc_ctl.urb[i] = urb;
452
453 #ifndef CONFIG_DMA_NONCOHERENT
454 dev->isoc_ctl.transfer_buffer[i] = usb_alloc_coherent(dev->udev,
455 sb_size, GFP_KERNEL, &urb->transfer_dma);
456 #else
457 dev->isoc_ctl.transfer_buffer[i] = kmalloc(sb_size, GFP_KERNEL);
458 #endif
459 if (!dev->isoc_ctl.transfer_buffer[i]) {
460 stk1160_err("cannot alloc %d bytes for tx[%d] buffer\n",
461 sb_size, i);
462
463 /* Not enough transfer buffers, so just give up */
464 if (i < STK1160_MIN_BUFS)
465 goto free_i_bufs;
466 goto nomore_tx_bufs;
467 }
468 memset(dev->isoc_ctl.transfer_buffer[i], 0, sb_size);
469
470 /*
471 * FIXME: Where can I get the endpoint?
472 */
473 urb->dev = dev->udev;
474 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
475 urb->transfer_buffer = dev->isoc_ctl.transfer_buffer[i];
476 urb->transfer_buffer_length = sb_size;
477 urb->complete = stk1160_isoc_irq;
478 urb->context = dev;
479 urb->interval = 1;
480 urb->start_frame = 0;
481 urb->number_of_packets = max_packets;
482 #ifndef CONFIG_DMA_NONCOHERENT
483 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
484 #else
485 urb->transfer_flags = URB_ISO_ASAP;
486 #endif
487
488 k = 0;
489 for (j = 0; j < max_packets; j++) {
490 urb->iso_frame_desc[j].offset = k;
491 urb->iso_frame_desc[j].length =
492 dev->isoc_ctl.max_pkt_size;
493 k += dev->isoc_ctl.max_pkt_size;
494 }
495 }
496
497 stk1160_dbg("%d urbs allocated\n", num_bufs);
498
499 /* At last we can say we have some buffers */
500 dev->isoc_ctl.num_bufs = num_bufs;
501
502 return 0;
503
504 nomore_tx_bufs:
505 /*
506 * Failed to allocate desired buffer count. However, we may have
507 * enough to work fine, so we just free the extra urb,
508 * store the allocated count and keep going, fingers crossed!
509 */
510 usb_free_urb(dev->isoc_ctl.urb[i]);
511 dev->isoc_ctl.urb[i] = NULL;
512
513 stk1160_warn("%d urbs allocated. Trying to continue...\n", i - 1);
514
515 dev->isoc_ctl.num_bufs = i - 1;
516
517 return 0;
518
519 free_i_bufs:
520 /* Save the allocated buffers so far, so we can properly free them */
521 dev->isoc_ctl.num_bufs = i+1;
522 stk1160_free_isoc(dev);
523 return -ENOMEM;
524 }
525
526