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 1) check why we are getting them
111 * and 2) add ratelimit.
112 *
113 * UPDATE: One of the reasons (the only one?) for getting these
114 * is incorrect standard (mismatch between expected and configured).
115 * So perhaps, we could add a counter for errors. When the counter
116 * reaches some value, we simply stop streaming.
117 */
118
119 len -= 4;
120 src += 4;
121
122 remain = len;
123
124 linesdone = buf->pos / bytesperline;
125 lineoff = buf->pos % bytesperline; /* offset in current line */
126
127 if (!buf->odd)
128 dst += bytesperline;
129
130 /* Multiply linesdone by two, to take account of the other field */
131 dst += linesdone * bytesperline * 2 + lineoff;
132
133 /* Copy the remaining of current line */
134 if (remain < (bytesperline - lineoff))
135 lencopy = remain;
136 else
137 lencopy = bytesperline - lineoff;
138
139 /*
140 * Check if we have enough space left in the buffer.
141 * In that case, we force loop exit after copy.
142 */
143 if (lencopy > buf->bytesused - buf->length) {
144 lencopy = buf->bytesused - buf->length;
145 remain = lencopy;
146 }
147
148 /* Check if the copy is done */
149 if (lencopy == 0 || remain == 0)
150 return;
151
152 /* Let the bug hunt begin! sanity checks! */
153 if (lencopy < 0) {
154 stk1160_dbg("copy skipped: negative lencopy\n");
155 return;
156 }
157
158 if ((unsigned long)dst + lencopy >
159 (unsigned long)buf->mem + buf->length) {
160 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
161 return;
162 }
163
164 memcpy(dst, src, lencopy);
165
166 buf->bytesused += lencopy;
167 buf->pos += lencopy;
168 remain -= lencopy;
169
170 /* Copy current field line by line, interlacing with the other field */
171 while (remain > 0) {
172
173 dst += lencopy + bytesperline;
174 src += lencopy;
175
176 /* Copy one line at a time */
177 if (remain < bytesperline)
178 lencopy = remain;
179 else
180 lencopy = bytesperline;
181
182 /*
183 * Check if we have enough space left in the buffer.
184 * In that case, we force loop exit after copy.
185 */
186 if (lencopy > buf->bytesused - buf->length) {
187 lencopy = buf->bytesused - buf->length;
188 remain = lencopy;
189 }
190
191 /* Check if the copy is done */
192 if (lencopy == 0 || remain == 0)
193 return;
194
195 if (lencopy < 0) {
196 printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
197 return;
198 }
199
200 if ((unsigned long)dst + lencopy >
201 (unsigned long)buf->mem + buf->length) {
202 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
203 return;
204 }
205
206 memcpy(dst, src, lencopy);
207 remain -= lencopy;
208
209 buf->bytesused += lencopy;
210 buf->pos += lencopy;
211 }
212 }
213
214 /*
215 * Controls the isoc copy of each urb packet
216 */
stk1160_process_isoc(struct stk1160 * dev,struct urb * urb)217 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
218 {
219 int i, len, status;
220 u8 *p;
221
222 if (!dev) {
223 stk1160_warn("%s called with null device\n", __func__);
224 return;
225 }
226
227 if (urb->status < 0) {
228 /* Print status and drop current packet (or field?) */
229 print_err_status(dev, -1, urb->status);
230 return;
231 }
232
233 for (i = 0; i < urb->number_of_packets; i++) {
234 status = urb->iso_frame_desc[i].status;
235 if (status < 0) {
236 print_err_status(dev, i, status);
237 continue;
238 }
239
240 /* Get packet actual length and pointer to data */
241 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
242 len = urb->iso_frame_desc[i].actual_length;
243
244 /* Empty packet */
245 if (len <= 4)
246 continue;
247
248 /*
249 * An 8-byte packet sequence means end of field.
250 * So if we don't have any packet, we start receiving one now
251 * and if we do have a packet, then we are done with it.
252 *
253 * These end of field packets are always 0xc0 or 0x80,
254 * but not always 8-byte long so we don't check packet length.
255 */
256 if (p[0] == 0xc0) {
257
258 /*
259 * If first byte is 0xc0 then we received
260 * second field, and frame has ended.
261 */
262 if (dev->isoc_ctl.buf != NULL)
263 stk1160_buffer_done(dev);
264
265 dev->isoc_ctl.buf = stk1160_next_buffer(dev);
266 if (dev->isoc_ctl.buf == NULL)
267 return;
268 }
269
270 /*
271 * If we don't have a buffer here, then it means we
272 * haven't found the start mark sequence.
273 */
274 if (dev->isoc_ctl.buf == NULL)
275 continue;
276
277 if (p[0] == 0xc0 || p[0] == 0x80) {
278
279 /* We set next packet parity and
280 * continue to get next one
281 */
282 dev->isoc_ctl.buf->odd = *p & 0x40;
283 dev->isoc_ctl.buf->pos = 0;
284 continue;
285 }
286
287 stk1160_copy_video(dev, p, len);
288 }
289 }
290
291
292 /*
293 * IRQ callback, called by URB callback
294 */
stk1160_isoc_irq(struct urb * urb)295 static void stk1160_isoc_irq(struct urb *urb)
296 {
297 int i, rc;
298 struct stk1160_urb *stk_urb = urb->context;
299 struct stk1160 *dev = stk_urb->dev;
300 struct device *dma_dev = stk1160_get_dmadev(dev);
301
302 switch (urb->status) {
303 case 0:
304 break;
305 case -ECONNRESET: /* kill */
306 case -ENOENT:
307 case -ESHUTDOWN:
308 /* TODO: check uvc driver: he frees the queue here */
309 return;
310 default:
311 stk1160_err("urb error! status %d\n", urb->status);
312 return;
313 }
314
315 invalidate_kernel_vmap_range(stk_urb->transfer_buffer,
316 urb->transfer_buffer_length);
317 dma_sync_sgtable_for_cpu(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
318
319 stk1160_process_isoc(dev, urb);
320
321 /* Reset urb buffers */
322 for (i = 0; i < urb->number_of_packets; i++) {
323 urb->iso_frame_desc[i].status = 0;
324 urb->iso_frame_desc[i].actual_length = 0;
325 }
326
327 dma_sync_sgtable_for_device(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
328 rc = usb_submit_urb(urb, GFP_ATOMIC);
329 if (rc)
330 stk1160_err("urb re-submit failed (%d)\n", rc);
331 }
332
333 /*
334 * Cancel urbs
335 * This function can't be called in atomic context
336 */
stk1160_cancel_isoc(struct stk1160 * dev)337 void stk1160_cancel_isoc(struct stk1160 *dev)
338 {
339 int i, num_bufs = dev->isoc_ctl.num_bufs;
340
341 /*
342 * This check is not necessary, but we add it
343 * to avoid a spurious debug message
344 */
345 if (!num_bufs)
346 return;
347
348 stk1160_dbg("killing %d urbs...\n", num_bufs);
349
350 for (i = 0; i < num_bufs; i++) {
351
352 /*
353 * To kill urbs we can't be in atomic context.
354 * We don't care for NULL pointer since
355 * usb_kill_urb allows it.
356 */
357 usb_kill_urb(dev->isoc_ctl.urb_ctl[i].urb);
358 }
359
360 stk1160_dbg("all urbs killed\n");
361 }
362
stk_free_urb(struct stk1160 * dev,struct stk1160_urb * stk_urb)363 static void stk_free_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb)
364 {
365 struct device *dma_dev = stk1160_get_dmadev(dev);
366
367 dma_vunmap_noncontiguous(dma_dev, stk_urb->transfer_buffer);
368 dma_free_noncontiguous(dma_dev, stk_urb->urb->transfer_buffer_length,
369 stk_urb->sgt, DMA_FROM_DEVICE);
370 usb_free_urb(stk_urb->urb);
371
372 stk_urb->transfer_buffer = NULL;
373 stk_urb->sgt = NULL;
374 stk_urb->urb = NULL;
375 stk_urb->dev = NULL;
376 stk_urb->dma = 0;
377 }
378
379 /*
380 * Releases urb and transfer buffers
381 * Obviusly, associated urb must be killed before releasing it.
382 */
stk1160_free_isoc(struct stk1160 * dev)383 void stk1160_free_isoc(struct stk1160 *dev)
384 {
385 int i, num_bufs = dev->isoc_ctl.num_bufs;
386
387 stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
388
389 for (i = 0; i < num_bufs; i++)
390 stk_free_urb(dev, &dev->isoc_ctl.urb_ctl[i]);
391
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
stk1160_fill_urb(struct stk1160 * dev,struct stk1160_urb * stk_urb,int sb_size,int max_packets)407 static int stk1160_fill_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb,
408 int sb_size, int max_packets)
409 {
410 struct device *dma_dev = stk1160_get_dmadev(dev);
411
412 stk_urb->urb = usb_alloc_urb(max_packets, GFP_KERNEL);
413 if (!stk_urb->urb)
414 return -ENOMEM;
415 stk_urb->sgt = dma_alloc_noncontiguous(dma_dev, sb_size,
416 DMA_FROM_DEVICE, GFP_KERNEL, 0);
417
418 /*
419 * If the buffer allocation failed, we exit but return 0 since
420 * we allow the driver working with less buffers
421 */
422 if (!stk_urb->sgt)
423 goto free_urb;
424
425 stk_urb->transfer_buffer = dma_vmap_noncontiguous(dma_dev, sb_size,
426 stk_urb->sgt);
427 if (!stk_urb->transfer_buffer)
428 goto free_sgt;
429
430 stk_urb->dma = stk_urb->sgt->sgl->dma_address;
431 stk_urb->dev = dev;
432 return 0;
433 free_sgt:
434 dma_free_noncontiguous(dma_dev, sb_size, stk_urb->sgt, DMA_FROM_DEVICE);
435 stk_urb->sgt = NULL;
436 free_urb:
437 usb_free_urb(stk_urb->urb);
438 stk_urb->urb = NULL;
439
440 return 0;
441 }
442 /*
443 * Allocate URBs
444 */
stk1160_alloc_isoc(struct stk1160 * dev)445 int stk1160_alloc_isoc(struct stk1160 *dev)
446 {
447 struct urb *urb;
448 int i, j, k, sb_size, max_packets, num_bufs;
449 int ret;
450
451 /*
452 * It may be necessary to release isoc here,
453 * since isoc are only released on disconnection.
454 * (see new_pkt_size flag)
455 */
456 if (dev->isoc_ctl.num_bufs)
457 stk1160_uninit_isoc(dev);
458
459 stk1160_dbg("allocating urbs...\n");
460
461 num_bufs = STK1160_NUM_BUFS;
462 max_packets = STK1160_NUM_PACKETS;
463 sb_size = max_packets * dev->max_pkt_size;
464
465 dev->isoc_ctl.buf = NULL;
466 dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
467
468 /* allocate urbs and transfer buffers */
469 for (i = 0; i < num_bufs; i++) {
470
471 ret = stk1160_fill_urb(dev, &dev->isoc_ctl.urb_ctl[i],
472 sb_size, max_packets);
473 if (ret)
474 goto free_i_bufs;
475
476 urb = dev->isoc_ctl.urb_ctl[i].urb;
477
478 if (!urb) {
479 /* Not enough transfer buffers, so just give up */
480 if (i < STK1160_MIN_BUFS)
481 goto free_i_bufs;
482 goto nomore_tx_bufs;
483 }
484 memset(dev->isoc_ctl.urb_ctl[i].transfer_buffer, 0, sb_size);
485
486 /*
487 * FIXME: Where can I get the endpoint?
488 */
489 urb->dev = dev->udev;
490 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
491 urb->transfer_buffer = dev->isoc_ctl.urb_ctl[i].transfer_buffer;
492 urb->transfer_buffer_length = sb_size;
493 urb->complete = stk1160_isoc_irq;
494 urb->context = &dev->isoc_ctl.urb_ctl[i];
495 urb->interval = 1;
496 urb->start_frame = 0;
497 urb->number_of_packets = max_packets;
498 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
499 urb->transfer_dma = dev->isoc_ctl.urb_ctl[i].dma;
500
501 k = 0;
502 for (j = 0; j < max_packets; j++) {
503 urb->iso_frame_desc[j].offset = k;
504 urb->iso_frame_desc[j].length =
505 dev->isoc_ctl.max_pkt_size;
506 k += dev->isoc_ctl.max_pkt_size;
507 }
508 }
509
510 stk1160_dbg("%d urbs allocated\n", num_bufs);
511
512 /* At last we can say we have some buffers */
513 dev->isoc_ctl.num_bufs = num_bufs;
514
515 return 0;
516
517 nomore_tx_bufs:
518 /*
519 * Failed to allocate desired buffer count. However, we may have
520 * enough to work fine, so we just free the extra urb,
521 * store the allocated count and keep going, fingers crossed!
522 */
523
524 stk1160_warn("%d urbs allocated. Trying to continue...\n", i);
525
526 dev->isoc_ctl.num_bufs = i;
527
528 return 0;
529
530 free_i_bufs:
531 /* Save the allocated buffers so far, so we can properly free them */
532 dev->isoc_ctl.num_bufs = i;
533 stk1160_free_isoc(dev);
534 return -ENOMEM;
535 }
536
537