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
20static unsigned int debug;
21module_param(debug, int, 0644);
22MODULE_PARM_DESC(debug, "enable debug messages");
23
24static 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
64static inline
65struct 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(head: &dev->avail_bufs)) {
75 buf = list_first_entry(&dev->avail_bufs,
76 struct stk1160_buffer, list);
77 list_del(entry: &buf->list);
78 }
79 spin_unlock_irqrestore(lock: &dev->buf_lock, flags);
80
81 return buf;
82}
83
84static inline
85void 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(vb: &buf->vb.vb2_buf, plane_no: 0, size: buf->bytesused);
94 vb2_buffer_done(vb: &buf->vb.vb2_buf, state: VB2_BUF_STATE_DONE);
95
96 dev->isoc_ctl.buf = NULL;
97}
98
99static inline
100void 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 */
216static 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, packet: -1, status: 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, packet: 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, src: p, len);
287 }
288}
289
290
291/*
292 * IRQ callback, called by URB callback
293 */
294static void stk1160_isoc_irq(struct urb *urb)
295{
296 int i, rc;
297 struct stk1160_urb *stk_urb = urb->context;
298 struct stk1160 *dev = stk_urb->dev;
299 struct device *dma_dev = stk1160_get_dmadev(dev);
300
301 switch (urb->status) {
302 case 0:
303 break;
304 case -ECONNRESET: /* kill */
305 case -ENOENT:
306 case -ESHUTDOWN:
307 /* TODO: check uvc driver: he frees the queue here */
308 return;
309 default:
310 stk1160_err("urb error! status %d\n", urb->status);
311 return;
312 }
313
314 invalidate_kernel_vmap_range(vaddr: stk_urb->transfer_buffer,
315 size: urb->transfer_buffer_length);
316 dma_sync_sgtable_for_cpu(dev: dma_dev, sgt: stk_urb->sgt, dir: DMA_FROM_DEVICE);
317
318 stk1160_process_isoc(dev, urb);
319
320 /* Reset urb buffers */
321 for (i = 0; i < urb->number_of_packets; i++) {
322 urb->iso_frame_desc[i].status = 0;
323 urb->iso_frame_desc[i].actual_length = 0;
324 }
325
326 dma_sync_sgtable_for_device(dev: dma_dev, sgt: stk_urb->sgt, dir: DMA_FROM_DEVICE);
327 rc = usb_submit_urb(urb, GFP_ATOMIC);
328 if (rc)
329 stk1160_err("urb re-submit failed (%d)\n", rc);
330}
331
332/*
333 * Cancel urbs
334 * This function can't be called in atomic context
335 */
336void stk1160_cancel_isoc(struct stk1160 *dev)
337{
338 int i, num_bufs = dev->isoc_ctl.num_bufs;
339
340 /*
341 * This check is not necessary, but we add it
342 * to avoid a spurious debug message
343 */
344 if (!num_bufs)
345 return;
346
347 stk1160_dbg("killing %d urbs...\n", num_bufs);
348
349 for (i = 0; i < num_bufs; i++) {
350
351 /*
352 * To kill urbs we can't be in atomic context.
353 * We don't care for NULL pointer since
354 * usb_kill_urb allows it.
355 */
356 usb_kill_urb(urb: dev->isoc_ctl.urb_ctl[i].urb);
357 }
358
359 stk1160_dbg("all urbs killed\n");
360}
361
362static void stk_free_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb)
363{
364 struct device *dma_dev = stk1160_get_dmadev(dev);
365
366 dma_vunmap_noncontiguous(dev: dma_dev, vaddr: stk_urb->transfer_buffer);
367 dma_free_noncontiguous(dev: dma_dev, size: stk_urb->urb->transfer_buffer_length,
368 sgt: stk_urb->sgt, dir: DMA_FROM_DEVICE);
369 usb_free_urb(urb: stk_urb->urb);
370
371 stk_urb->transfer_buffer = NULL;
372 stk_urb->sgt = NULL;
373 stk_urb->urb = NULL;
374 stk_urb->dev = NULL;
375 stk_urb->dma = 0;
376}
377
378/*
379 * Releases urb and transfer buffers
380 * Obviusly, associated urb must be killed before releasing it.
381 */
382void stk1160_free_isoc(struct stk1160 *dev)
383{
384 int i, num_bufs = dev->isoc_ctl.num_bufs;
385
386 stk1160_dbg("freeing %d urb buffers...\n", num_bufs);
387
388 for (i = 0; i < num_bufs; i++)
389 stk_free_urb(dev, stk_urb: &dev->isoc_ctl.urb_ctl[i]);
390
391 dev->isoc_ctl.num_bufs = 0;
392
393 stk1160_dbg("all urb buffers freed\n");
394}
395
396/*
397 * Helper for cancelling and freeing urbs
398 * This function can't be called in atomic context
399 */
400void stk1160_uninit_isoc(struct stk1160 *dev)
401{
402 stk1160_cancel_isoc(dev);
403 stk1160_free_isoc(dev);
404}
405
406static int stk1160_fill_urb(struct stk1160 *dev, struct stk1160_urb *stk_urb,
407 int sb_size, int max_packets)
408{
409 struct device *dma_dev = stk1160_get_dmadev(dev);
410
411 stk_urb->urb = usb_alloc_urb(iso_packets: max_packets, GFP_KERNEL);
412 if (!stk_urb->urb)
413 return -ENOMEM;
414 stk_urb->sgt = dma_alloc_noncontiguous(dev: dma_dev, size: sb_size,
415 dir: DMA_FROM_DEVICE, GFP_KERNEL, attrs: 0);
416
417 /*
418 * If the buffer allocation failed, we exit but return 0 since
419 * we allow the driver working with less buffers
420 */
421 if (!stk_urb->sgt)
422 goto free_urb;
423
424 stk_urb->transfer_buffer = dma_vmap_noncontiguous(dev: dma_dev, size: sb_size,
425 sgt: stk_urb->sgt);
426 if (!stk_urb->transfer_buffer)
427 goto free_sgt;
428
429 stk_urb->dma = stk_urb->sgt->sgl->dma_address;
430 stk_urb->dev = dev;
431 return 0;
432free_sgt:
433 dma_free_noncontiguous(dev: dma_dev, size: sb_size, sgt: stk_urb->sgt, dir: DMA_FROM_DEVICE);
434 stk_urb->sgt = NULL;
435free_urb:
436 usb_free_urb(urb: stk_urb->urb);
437 stk_urb->urb = NULL;
438
439 return 0;
440}
441/*
442 * Allocate URBs
443 */
444int stk1160_alloc_isoc(struct stk1160 *dev)
445{
446 struct urb *urb;
447 int i, j, k, sb_size, max_packets, num_bufs;
448 int ret;
449
450 /*
451 * It may be necessary to release isoc here,
452 * since isoc are only released on disconnection.
453 * (see new_pkt_size flag)
454 */
455 if (dev->isoc_ctl.num_bufs)
456 stk1160_uninit_isoc(dev);
457
458 stk1160_dbg("allocating urbs...\n");
459
460 num_bufs = STK1160_NUM_BUFS;
461 max_packets = STK1160_NUM_PACKETS;
462 sb_size = max_packets * dev->max_pkt_size;
463
464 dev->isoc_ctl.buf = NULL;
465 dev->isoc_ctl.max_pkt_size = dev->max_pkt_size;
466
467 /* allocate urbs and transfer buffers */
468 for (i = 0; i < num_bufs; i++) {
469
470 ret = stk1160_fill_urb(dev, stk_urb: &dev->isoc_ctl.urb_ctl[i],
471 sb_size, max_packets);
472 if (ret)
473 goto free_i_bufs;
474
475 urb = dev->isoc_ctl.urb_ctl[i].urb;
476
477 if (!urb) {
478 /* Not enough transfer buffers, so just give up */
479 if (i < STK1160_MIN_BUFS)
480 goto free_i_bufs;
481 goto nomore_tx_bufs;
482 }
483 memset(dev->isoc_ctl.urb_ctl[i].transfer_buffer, 0, sb_size);
484
485 /*
486 * FIXME: Where can I get the endpoint?
487 */
488 urb->dev = dev->udev;
489 urb->pipe = usb_rcvisocpipe(dev->udev, STK1160_EP_VIDEO);
490 urb->transfer_buffer = dev->isoc_ctl.urb_ctl[i].transfer_buffer;
491 urb->transfer_buffer_length = sb_size;
492 urb->complete = stk1160_isoc_irq;
493 urb->context = &dev->isoc_ctl.urb_ctl[i];
494 urb->interval = 1;
495 urb->start_frame = 0;
496 urb->number_of_packets = max_packets;
497 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
498 urb->transfer_dma = dev->isoc_ctl.urb_ctl[i].dma;
499
500 k = 0;
501 for (j = 0; j < max_packets; j++) {
502 urb->iso_frame_desc[j].offset = k;
503 urb->iso_frame_desc[j].length =
504 dev->isoc_ctl.max_pkt_size;
505 k += dev->isoc_ctl.max_pkt_size;
506 }
507 }
508
509 stk1160_dbg("%d urbs allocated\n", num_bufs);
510
511 /* At last we can say we have some buffers */
512 dev->isoc_ctl.num_bufs = num_bufs;
513
514 return 0;
515
516nomore_tx_bufs:
517 /*
518 * Failed to allocate desired buffer count. However, we may have
519 * enough to work fine, so we just free the extra urb,
520 * store the allocated count and keep going, fingers crossed!
521 */
522
523 stk1160_warn("%d urbs allocated. Trying to continue...\n", i);
524
525 dev->isoc_ctl.num_bufs = i;
526
527 return 0;
528
529free_i_bufs:
530 /* Save the allocated buffers so far, so we can properly free them */
531 dev->isoc_ctl.num_bufs = i;
532 stk1160_free_isoc(dev);
533 return -ENOMEM;
534}
535
536

source code of linux/drivers/media/usb/stk1160/stk1160-video.c