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 lencopy = min(remain, bytesperline - lineoff);
134
135 /*
136 * Check if we have enough space left in the buffer.
137 * In that case, we force loop exit after copy.
138 */
139 offset = dst - (u8 *)buf->mem;
140 if (offset > buf->length) {
141 dev_warn_ratelimited(dev->dev, "out of bounds offset\n");
142 return;
143 }
144 if (lencopy > buf->length - offset) {
145 lencopy = buf->length - offset;
146 remain = lencopy;
147 }
148
149 /* Check if the copy is done */
150 if (lencopy == 0 || remain == 0)
151 return;
152
153 /* Let the bug hunt begin! sanity checks! */
154 if (lencopy < 0) {
155 printk_ratelimited(KERN_DEBUG "copy skipped: negative lencopy\n");
156 return;
157 }
158
159 if ((unsigned long)dst + lencopy >
160 (unsigned long)buf->mem + buf->length) {
161 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
162 return;
163 }
164
165 memcpy(dst, src, lencopy);
166
167 buf->bytesused += lencopy;
168 buf->pos += lencopy;
169 remain -= lencopy;
170
171 /* Copy current field line by line, interlacing with the other field */
172 while (remain > 0) {
173
174 dst += lencopy + bytesperline;
175 src += lencopy;
176
177 /* Copy one line at a time */
178 lencopy = min(remain, bytesperline);
179
180 /*
181 * Check if we have enough space left in the buffer.
182 * In that case, we force loop exit after copy.
183 */
184 offset = dst - (u8 *)buf->mem;
185 if (offset > buf->length) {
186 dev_warn_ratelimited(dev->dev, "offset out of bounds\n");
187 return;
188 }
189 if (lencopy > buf->length - offset) {
190 lencopy = buf->length - offset;
191 remain = lencopy;
192 }
193
194 /* Check if the copy is done */
195 if (lencopy == 0 || remain == 0)
196 return;
197
198 if (lencopy < 0) {
199 printk_ratelimited(KERN_WARNING "stk1160: negative lencopy detected\n");
200 return;
201 }
202
203 if ((unsigned long)dst + lencopy >
204 (unsigned long)buf->mem + buf->length) {
205 printk_ratelimited(KERN_WARNING "stk1160: buffer overflow detected\n");
206 return;
207 }
208
209 memcpy(dst, src, lencopy);
210 remain -= lencopy;
211
212 buf->bytesused += lencopy;
213 buf->pos += lencopy;
214 }
215 }
216
217 /*
218 * Controls the isoc copy of each urb packet
219 */
stk1160_process_isoc(struct stk1160 * dev,struct urb * urb)220 static void stk1160_process_isoc(struct stk1160 *dev, struct urb *urb)
221 {
222 int i, len, status;
223 u8 *p;
224
225 if (!dev) {
226 stk1160_warn("%s called with null device\n", __func__);
227 return;
228 }
229
230 if (urb->status < 0) {
231 /* Print status and drop current packet (or field?) */
232 print_err_status(dev, -1, urb->status);
233 return;
234 }
235
236 for (i = 0; i < urb->number_of_packets; i++) {
237 status = urb->iso_frame_desc[i].status;
238 if (status < 0) {
239 print_err_status(dev, i, status);
240 continue;
241 }
242
243 /* Get packet actual length and pointer to data */
244 p = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
245 len = urb->iso_frame_desc[i].actual_length;
246
247 /* Empty packet */
248 if (len <= 4)
249 continue;
250
251 /*
252 * An 8-byte packet sequence means end of field.
253 * So if we don't have any packet, we start receiving one now
254 * and if we do have a packet, then we are done with it.
255 *
256 * These end of field packets are always 0xc0 or 0x80,
257 * but not always 8-byte long so we don't check packet length.
258 */
259 if (p[0] == 0xc0) {
260
261 /*
262 * If first byte is 0xc0 then we received
263 * second field, and frame has ended.
264 */
265 if (dev->isoc_ctl.buf != NULL)
266 stk1160_buffer_done(dev);
267
268 dev->isoc_ctl.buf = stk1160_next_buffer(dev);
269 if (dev->isoc_ctl.buf == NULL)
270 return;
271 }
272
273 /*
274 * If we don't have a buffer here, then it means we
275 * haven't found the start mark sequence.
276 */
277 if (dev->isoc_ctl.buf == NULL)
278 continue;
279
280 if (p[0] == 0xc0 || p[0] == 0x80) {
281
282 /* We set next packet parity and
283 * continue to get next one
284 */
285 dev->isoc_ctl.buf->odd = *p & 0x40;
286 dev->isoc_ctl.buf->pos = 0;
287 continue;
288 }
289
290 stk1160_copy_video(dev, p, len);
291 }
292 }
293
294
295 /*
296 * IRQ callback, called by URB callback
297 */
stk1160_isoc_irq(struct urb * urb)298 static void stk1160_isoc_irq(struct urb *urb)
299 {
300 int i, rc;
301 struct stk1160_urb *stk_urb = urb->context;
302 struct stk1160 *dev = stk_urb->dev;
303 struct device *dma_dev = stk1160_get_dmadev(dev);
304
305 switch (urb->status) {
306 case 0:
307 break;
308 case -ECONNRESET: /* kill */
309 case -ENOENT:
310 case -ESHUTDOWN:
311 /* TODO: check uvc driver: he frees the queue here */
312 return;
313 default:
314 stk1160_err("urb error! status %d\n", urb->status);
315 return;
316 }
317
318 invalidate_kernel_vmap_range(stk_urb->transfer_buffer,
319 urb->transfer_buffer_length);
320 dma_sync_sgtable_for_cpu(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
321
322 stk1160_process_isoc(dev, urb);
323
324 /* Reset urb buffers */
325 for (i = 0; i < urb->number_of_packets; i++) {
326 urb->iso_frame_desc[i].status = 0;
327 urb->iso_frame_desc[i].actual_length = 0;
328 }
329
330 dma_sync_sgtable_for_device(dma_dev, stk_urb->sgt, DMA_FROM_DEVICE);
331 rc = usb_submit_urb(urb, GFP_ATOMIC);
332 if (rc)
333 stk1160_err("urb re-submit failed (%d)\n", rc);
334 }
335
336 /*
337 * Cancel urbs
338 * This function can't be called in atomic context
339 */
stk1160_cancel_isoc(struct stk1160 * dev)340 void stk1160_cancel_isoc(struct stk1160 *dev)
341 {
342 int i, num_bufs = dev->isoc_ctl.num_bufs;
343
344 /*
345 * This check is not necessary, but we add it
346 * to avoid a spurious debug message
347 */
348 if (!num_bufs)
349 return;
350
351 stk1160_dbg("killing %d urbs...\n", num_bufs);
352
353 for (i = 0; i < num_bufs; i++) {
354
355 /*
356 * To kill urbs we can't be in atomic context.
357 * We don't care for NULL pointer since
358 * usb_kill_urb allows it.
359 */
360 usb_kill_urb(dev->isoc_ctl.urb_ctl[i].urb);
361 }
362
363 stk1160_dbg("all urbs killed\n");
364 }
365
stk_free_urb(struct stk1160 * dev,struct stk1160_urb * stk_urb)366 static void stk_free_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb)
367 {
368 struct device *dma_dev = stk1160_get_dmadev(dev);
369
370 dma_vunmap_noncontiguous(dma_dev, stk_urb->transfer_buffer);
371 dma_free_noncontiguous(dma_dev, stk_urb->urb->transfer_buffer_length,
372 stk_urb->sgt, DMA_FROM_DEVICE);
373 usb_free_urb(stk_urb->urb);
374
375 stk_urb->transfer_buffer = NULL;
376 stk_urb->sgt = NULL;
377 stk_urb->urb = NULL;
378 stk_urb->dev = NULL;
379 stk_urb->dma = 0;
380 }
381
382 /*
383 * Releases urb and transfer buffers
384 * Obviusly, associated urb must be killed before releasing it.
385 */
stk1160_free_isoc(struct stk1160 * dev)386 void stk1160_free_isoc(struct stk1160 *dev)
387 {
388 int i, num_bufs = dev->isoc_ctl.num_bufs;
389
390 stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
391
392 for (i = 0; i < num_bufs; i++)
393 stk_free_urb(dev, &dev->isoc_ctl.urb_ctl[i]);
394
395 dev->isoc_ctl.num_bufs = 0;
396
397 stk1160_dbg("all urb buffers freed\n");
398 }
399
400 /*
401 * Helper for cancelling and freeing urbs
402 * This function can't be called in atomic context
403 */
stk1160_uninit_isoc(struct stk1160 * dev)404 void stk1160_uninit_isoc(struct stk1160 *dev)
405 {
406 stk1160_cancel_isoc(dev);
407 stk1160_free_isoc(dev);
408 }
409
stk1160_fill_urb(struct stk1160 * dev,struct stk1160_urb * stk_urb,int sb_size,int max_packets)410 static int stk1160_fill_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb,
411 int sb_size, int max_packets)
412 {
413 struct device *dma_dev = stk1160_get_dmadev(dev);
414
415 stk_urb->urb = usb_alloc_urb(max_packets, GFP_KERNEL);
416 if (!stk_urb->urb)
417 return -ENOMEM;
418 stk_urb->sgt = dma_alloc_noncontiguous(dma_dev, sb_size,
419 DMA_FROM_DEVICE, GFP_KERNEL, 0);
420
421 /*
422 * If the buffer allocation failed, we exit but return 0 since
423 * we allow the driver working with less buffers
424 */
425 if (!stk_urb->sgt)
426 goto free_urb;
427
428 stk_urb->transfer_buffer = dma_vmap_noncontiguous(dma_dev, sb_size,
429 stk_urb->sgt);
430 if (!stk_urb->transfer_buffer)
431 goto free_sgt;
432
433 stk_urb->dma = stk_urb->sgt->sgl->dma_address;
434 stk_urb->dev = dev;
435 return 0;
436 free_sgt:
437 dma_free_noncontiguous(dma_dev, sb_size, stk_urb->sgt, DMA_FROM_DEVICE);
438 stk_urb->sgt = NULL;
439 free_urb:
440 usb_free_urb(stk_urb->urb);
441 stk_urb->urb = NULL;
442
443 return 0;
444 }
445 /*
446 * Allocate URBs
447 */
stk1160_alloc_isoc(struct stk1160 * dev)448 int stk1160_alloc_isoc(struct stk1160 *dev)
449 {
450 struct urb *urb;
451 int i, j, k, sb_size, max_packets, num_bufs;
452 int ret;
453
454 /*
455 * It may be necessary to release isoc here,
456 * since isoc are only released on disconnection.
457 * (see new_pkt_size flag)
458 */
459 if (dev->isoc_ctl.num_bufs)
460 stk1160_uninit_isoc(dev);
461
462 stk1160_dbg("allocating urbs...\n");
463
464 num_bufs = STK1160_NUM_BUFS;
465 max_packets = STK1160_NUM_PACKETS;
466 sb_size = max_packets * dev->max_pkt_size;
467
468 dev->isoc_ctl.buf = NULL;
469 dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
470
471 /* allocate urbs and transfer buffers */
472 for (i = 0; i < num_bufs; i++) {
473
474 ret = stk1160_fill_urb(dev, &dev->isoc_ctl.urb_ctl[i],
475 sb_size, max_packets);
476 if (ret)
477 goto free_i_bufs;
478
479 urb = dev->isoc_ctl.urb_ctl[i].urb;
480
481 if (!urb) {
482 /* Not enough transfer buffers, so just give up */
483 if (i < STK1160_MIN_BUFS)
484 goto free_i_bufs;
485 goto nomore_tx_bufs;
486 }
487 memset(dev->isoc_ctl.urb_ctl[i].transfer_buffer, 0, sb_size);
488
489 /*
490 * FIXME: Where can I get the endpoint?
491 */
492 urb->dev = dev->udev;
493 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
494 urb->transfer_buffer = dev->isoc_ctl.urb_ctl[i].transfer_buffer;
495 urb->transfer_buffer_length = sb_size;
496 urb->complete = stk1160_isoc_irq;
497 urb->context = &dev->isoc_ctl.urb_ctl[i];
498 urb->interval = 1;
499 urb->start_frame = 0;
500 urb->number_of_packets = max_packets;
501 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
502 urb->transfer_dma = dev->isoc_ctl.urb_ctl[i].dma;
503
504 k = 0;
505 for (j = 0; j < max_packets; j++) {
506 urb->iso_frame_desc[j].offset = k;
507 urb->iso_frame_desc[j].length =
508 dev->isoc_ctl.max_pkt_size;
509 k += dev->isoc_ctl.max_pkt_size;
510 }
511 }
512
513 stk1160_dbg("%d urbs allocated\n", num_bufs);
514
515 /* At last we can say we have some buffers */
516 dev->isoc_ctl.num_bufs = num_bufs;
517
518 return 0;
519
520 nomore_tx_bufs:
521 /*
522 * Failed to allocate desired buffer count. However, we may have
523 * enough to work fine, so we just free the extra urb,
524 * store the allocated count and keep going, fingers crossed!
525 */
526
527 stk1160_warn("%d urbs allocated. Trying to continue...\n", i);
528
529 dev->isoc_ctl.num_bufs = i;
530
531 return 0;
532
533 free_i_bufs:
534 /* Save the allocated buffers so far, so we can properly free them */
535 dev->isoc_ctl.num_bufs = i;
536 stk1160_free_isoc(dev);
537 return -ENOMEM;
538 }
539
540