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, offset;
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 offset = dst - (u8 *)buf->mem;
143 if (offset > buf->length) {
144 dev_warn_ratelimited(dev->dev, "out of bounds offset\n");
145 return;
146 }
147 if (lencopy > buf->length - offset) {
148 lencopy = buf->length - offset;
149 remain = lencopy;
150 }
151
152 /* Check if the copy is done */
153 if (lencopy == 0 || remain == 0)
154 return;
155
156 /* Let the bug hunt begin! sanity checks! */
157 if (lencopy < 0) {
158 printk_ratelimited(KERN_DEBUG "copy skipped: negative lencopy\n");
159 return;
160 }
161
162 if ((unsigned long)dst + lencopy >
163 (unsigned long)buf->mem + buf->length) {
164 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
165 return;
166 }
167
168 memcpy(dst, src, lencopy);
169
170 buf->bytesused += lencopy;
171 buf->pos += lencopy;
172 remain -= lencopy;
173
174 /* Copy current field line by line, interlacing with the other field */
175 while (remain > 0) {
176
177 dst += lencopy + bytesperline;
178 src += lencopy;
179
180 /* Copy one line at a time */
181 if (remain < bytesperline)
182 lencopy = remain;
183 else
184 lencopy = bytesperline;
185
186 /*
187 * Check if we have enough space left in the buffer.
188 * In that case, we force loop exit after copy.
189 */
190 offset = dst - (u8 *)buf->mem;
191 if (offset > buf->length) {
192 dev_warn_ratelimited(dev->dev, "offset out of bounds\n");
193 return;
194 }
195 if (lencopy > buf->length - offset) {
196 lencopy = buf->length - offset;
197 remain = lencopy;
198 }
199
200 /* Check if the copy is done */
201 if (lencopy == 0 || remain == 0)
202 return;
203
204 if (lencopy < 0) {
205 printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
206 return;
207 }
208
209 if ((unsigned long)dst + lencopy >
210 (unsigned long)buf->mem + buf->length) {
211 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
212 return;
213 }
214
215 memcpy(dst, src, lencopy);
216 remain -= lencopy;
217
218 buf->bytesused += lencopy;
219 buf->pos += lencopy;
220 }
221 }
222
223 /*
224 * Controls the isoc copy of each urb packet
225 */
stk1160_process_isoc(struct stk1160 * dev,struct urb * urb)226 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
227 {
228 int i, len, status;
229 u8 *p;
230
231 if (!dev) {
232 stk1160_warn("%s called with null device\n", __func__);
233 return;
234 }
235
236 if (urb->status < 0) {
237 /* Print status and drop current packet (or field?) */
238 print_err_status(dev, -1, urb->status);
239 return;
240 }
241
242 for (i = 0; i < urb->number_of_packets; i++) {
243 status = urb->iso_frame_desc[i].status;
244 if (status < 0) {
245 print_err_status(dev, i, status);
246 continue;
247 }
248
249 /* Get packet actual length and pointer to data */
250 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
251 len = urb->iso_frame_desc[i].actual_length;
252
253 /* Empty packet */
254 if (len <= 4)
255 continue;
256
257 /*
258 * An 8-byte packet sequence means end of field.
259 * So if we don't have any packet, we start receiving one now
260 * and if we do have a packet, then we are done with it.
261 *
262 * These end of field packets are always 0xc0 or 0x80,
263 * but not always 8-byte long so we don't check packet length.
264 */
265 if (p[0] == 0xc0) {
266
267 /*
268 * If first byte is 0xc0 then we received
269 * second field, and frame has ended.
270 */
271 if (dev->isoc_ctl.buf != NULL)
272 stk1160_buffer_done(dev);
273
274 dev->isoc_ctl.buf = stk1160_next_buffer(dev);
275 if (dev->isoc_ctl.buf == NULL)
276 return;
277 }
278
279 /*
280 * If we don't have a buffer here, then it means we
281 * haven't found the start mark sequence.
282 */
283 if (dev->isoc_ctl.buf == NULL)
284 continue;
285
286 if (p[0] == 0xc0 || p[0] == 0x80) {
287
288 /* We set next packet parity and
289 * continue to get next one
290 */
291 dev->isoc_ctl.buf->odd = *p & 0x40;
292 dev->isoc_ctl.buf->pos = 0;
293 continue;
294 }
295
296 stk1160_copy_video(dev, p, len);
297 }
298 }
299
300
301 /*
302 * IRQ callback, called by URB callback
303 */
stk1160_isoc_irq(struct urb * urb)304 static void stk1160_isoc_irq(struct urb *urb)
305 {
306 int i, rc;
307 struct stk1160_urb *stk_urb = urb->context;
308 struct stk1160 *dev = stk_urb->dev;
309 struct device *dma_dev = stk1160_get_dmadev(dev);
310
311 switch (urb->status) {
312 case 0:
313 break;
314 case -ECONNRESET: /* kill */
315 case -ENOENT:
316 case -ESHUTDOWN:
317 /* TODO: check uvc driver: he frees the queue here */
318 return;
319 default:
320 stk1160_err("urb error! status %d\n", urb->status);
321 return;
322 }
323
324 invalidate_kernel_vmap_range(stk_urb->transfer_buffer,
325 urb->transfer_buffer_length);
326 dma_sync_sgtable_for_cpu(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
327
328 stk1160_process_isoc(dev, urb);
329
330 /* Reset urb buffers */
331 for (i = 0; i < urb->number_of_packets; i++) {
332 urb->iso_frame_desc[i].status = 0;
333 urb->iso_frame_desc[i].actual_length = 0;
334 }
335
336 dma_sync_sgtable_for_device(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
337 rc = usb_submit_urb(urb, GFP_ATOMIC);
338 if (rc)
339 stk1160_err("urb re-submit failed (%d)\n", rc);
340 }
341
342 /*
343 * Cancel urbs
344 * This function can't be called in atomic context
345 */
stk1160_cancel_isoc(struct stk1160 * dev)346 void stk1160_cancel_isoc(struct stk1160 *dev)
347 {
348 int i, num_bufs = dev->isoc_ctl.num_bufs;
349
350 /*
351 * This check is not necessary, but we add it
352 * to avoid a spurious debug message
353 */
354 if (!num_bufs)
355 return;
356
357 stk1160_dbg("killing %d urbs...\n", num_bufs);
358
359 for (i = 0; i < num_bufs; i++) {
360
361 /*
362 * To kill urbs we can't be in atomic context.
363 * We don't care for NULL pointer since
364 * usb_kill_urb allows it.
365 */
366 usb_kill_urb(dev->isoc_ctl.urb_ctl[i].urb);
367 }
368
369 stk1160_dbg("all urbs killed\n");
370 }
371
stk_free_urb(struct stk1160 * dev,struct stk1160_urb * stk_urb)372 static void stk_free_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb)
373 {
374 struct device *dma_dev = stk1160_get_dmadev(dev);
375
376 dma_vunmap_noncontiguous(dma_dev, stk_urb->transfer_buffer);
377 dma_free_noncontiguous(dma_dev, stk_urb->urb->transfer_buffer_length,
378 stk_urb->sgt, DMA_FROM_DEVICE);
379 usb_free_urb(stk_urb->urb);
380
381 stk_urb->transfer_buffer = NULL;
382 stk_urb->sgt = NULL;
383 stk_urb->urb = NULL;
384 stk_urb->dev = NULL;
385 stk_urb->dma = 0;
386 }
387
388 /*
389 * Releases urb and transfer buffers
390 * Obviusly, associated urb must be killed before releasing it.
391 */
stk1160_free_isoc(struct stk1160 * dev)392 void stk1160_free_isoc(struct stk1160 *dev)
393 {
394 int i, num_bufs = dev->isoc_ctl.num_bufs;
395
396 stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
397
398 for (i = 0; i < num_bufs; i++)
399 stk_free_urb(dev, &dev->isoc_ctl.urb_ctl[i]);
400
401 dev->isoc_ctl.num_bufs = 0;
402
403 stk1160_dbg("all urb buffers freed\n");
404 }
405
406 /*
407 * Helper for cancelling and freeing urbs
408 * This function can't be called in atomic context
409 */
stk1160_uninit_isoc(struct stk1160 * dev)410 void stk1160_uninit_isoc(struct stk1160 *dev)
411 {
412 stk1160_cancel_isoc(dev);
413 stk1160_free_isoc(dev);
414 }
415
stk1160_fill_urb(struct stk1160 * dev,struct stk1160_urb * stk_urb,int sb_size,int max_packets)416 static int stk1160_fill_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb,
417 int sb_size, int max_packets)
418 {
419 struct device *dma_dev = stk1160_get_dmadev(dev);
420
421 stk_urb->urb = usb_alloc_urb(max_packets, GFP_KERNEL);
422 if (!stk_urb->urb)
423 return -ENOMEM;
424 stk_urb->sgt = dma_alloc_noncontiguous(dma_dev, sb_size,
425 DMA_FROM_DEVICE, GFP_KERNEL, 0);
426
427 /*
428 * If the buffer allocation failed, we exit but return 0 since
429 * we allow the driver working with less buffers
430 */
431 if (!stk_urb->sgt)
432 goto free_urb;
433
434 stk_urb->transfer_buffer = dma_vmap_noncontiguous(dma_dev, sb_size,
435 stk_urb->sgt);
436 if (!stk_urb->transfer_buffer)
437 goto free_sgt;
438
439 stk_urb->dma = stk_urb->sgt->sgl->dma_address;
440 stk_urb->dev = dev;
441 return 0;
442 free_sgt:
443 dma_free_noncontiguous(dma_dev, sb_size, stk_urb->sgt, DMA_FROM_DEVICE);
444 stk_urb->sgt = NULL;
445 free_urb:
446 usb_free_urb(stk_urb->urb);
447 stk_urb->urb = NULL;
448
449 return 0;
450 }
451 /*
452 * Allocate URBs
453 */
stk1160_alloc_isoc(struct stk1160 * dev)454 int stk1160_alloc_isoc(struct stk1160 *dev)
455 {
456 struct urb *urb;
457 int i, j, k, sb_size, max_packets, num_bufs;
458 int ret;
459
460 /*
461 * It may be necessary to release isoc here,
462 * since isoc are only released on disconnection.
463 * (see new_pkt_size flag)
464 */
465 if (dev->isoc_ctl.num_bufs)
466 stk1160_uninit_isoc(dev);
467
468 stk1160_dbg("allocating urbs...\n");
469
470 num_bufs = STK1160_NUM_BUFS;
471 max_packets = STK1160_NUM_PACKETS;
472 sb_size = max_packets * dev->max_pkt_size;
473
474 dev->isoc_ctl.buf = NULL;
475 dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
476
477 /* allocate urbs and transfer buffers */
478 for (i = 0; i < num_bufs; i++) {
479
480 ret = stk1160_fill_urb(dev, &dev->isoc_ctl.urb_ctl[i],
481 sb_size, max_packets);
482 if (ret)
483 goto free_i_bufs;
484
485 urb = dev->isoc_ctl.urb_ctl[i].urb;
486
487 if (!urb) {
488 /* Not enough transfer buffers, so just give up */
489 if (i < STK1160_MIN_BUFS)
490 goto free_i_bufs;
491 goto nomore_tx_bufs;
492 }
493 memset(dev->isoc_ctl.urb_ctl[i].transfer_buffer, 0, sb_size);
494
495 /*
496 * FIXME: Where can I get the endpoint?
497 */
498 urb->dev = dev->udev;
499 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
500 urb->transfer_buffer = dev->isoc_ctl.urb_ctl[i].transfer_buffer;
501 urb->transfer_buffer_length = sb_size;
502 urb->complete = stk1160_isoc_irq;
503 urb->context = &dev->isoc_ctl.urb_ctl[i];
504 urb->interval = 1;
505 urb->start_frame = 0;
506 urb->number_of_packets = max_packets;
507 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
508 urb->transfer_dma = dev->isoc_ctl.urb_ctl[i].dma;
509
510 k = 0;
511 for (j = 0; j < max_packets; j++) {
512 urb->iso_frame_desc[j].offset = k;
513 urb->iso_frame_desc[j].length =
514 dev->isoc_ctl.max_pkt_size;
515 k += dev->isoc_ctl.max_pkt_size;
516 }
517 }
518
519 stk1160_dbg("%d urbs allocated\n", num_bufs);
520
521 /* At last we can say we have some buffers */
522 dev->isoc_ctl.num_bufs = num_bufs;
523
524 return 0;
525
526 nomore_tx_bufs:
527 /*
528 * Failed to allocate desired buffer count. However, we may have
529 * enough to work fine, so we just free the extra urb,
530 * store the allocated count and keep going, fingers crossed!
531 */
532
533 stk1160_warn("%d urbs allocated. Trying to continue...\n", i);
534
535 dev->isoc_ctl.num_bufs = i;
536
537 return 0;
538
539 free_i_bufs:
540 /* Save the allocated buffers so far, so we can properly free them */
541 dev->isoc_ctl.num_bufs = i;
542 stk1160_free_isoc(dev);
543 return -ENOMEM;
544 }
545
546