2 em2820-core.c - driver for Empia EM2820/2840 USB video capture devices
4 Copyright (C) 2005 Markus Rechberger <mrechberger@gmail.com>
5 Ludovico Cavedon <cavedon@sssup.it>
6 Mauro Carvalho Chehab <mchehab@brturbo.com.br>
8 Based on the em2800 driver from Sascha Sommer <saschasommer@freenet.de>
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <linux/init.h>
26 #include <linux/list.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/videodev.h>
30 #include <linux/usb.h>
31 #include <linux/vmalloc.h>
35 /* #define ENABLE_DEBUG_ISOC_FRAMES */
37 unsigned int core_debug = 0;
38 module_param(core_debug,int,0644);
39 MODULE_PARM_DESC(core_debug,"enable debug messages [core]");
41 #define em2820_coredbg(fmt, arg...) do {\
43 printk(KERN_INFO "%s %s :"fmt, \
44 dev->name, __FUNCTION__ , ##arg); } while (0)
46 unsigned int reg_debug = 0;
47 module_param(reg_debug,int,0644);
48 MODULE_PARM_DESC(reg_debug,"enable debug messages [URB reg]");
50 #define em2820_regdbg(fmt, arg...) do {\
52 printk(KERN_INFO "%s %s :"fmt, \
53 dev->name, __FUNCTION__ , ##arg); } while (0)
55 unsigned int isoc_debug = 0;
56 module_param(isoc_debug,int,0644);
57 MODULE_PARM_DESC(core_debug,"enable debug messages [isoc transfers]");
59 #define em2820_isocdbg(fmt, arg...) do {\
61 printk(KERN_INFO "%s %s :"fmt, \
62 dev->name, __FUNCTION__ , ##arg); } while (0)
64 static int alt = EM2820_PINOUT;
65 module_param(alt, int, 0644);
66 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");
68 /* ------------------------------------------------------------------ */
69 /* debug help functions */
71 static const char *v4l1_ioctls[] = {
72 "0", "CGAP", "GCHAN", "SCHAN", "GTUNER", "STUNER", "GPICT", "SPICT",
73 "CCAPTURE", "GWIN", "SWIN", "GFBUF", "SFBUF", "KEY", "GFREQ",
74 "SFREQ", "GAUDIO", "SAUDIO", "SYNC", "MCAPTURE", "GMBUF", "GUNIT",
75 "GCAPTURE", "SCAPTURE", "SPLAYMODE", "SWRITEMODE", "GPLAYINFO",
76 "SMICROCODE", "GVBIFMT", "SVBIFMT" };
77 #define V4L1_IOCTLS ARRAY_SIZE(v4l1_ioctls)
79 static const char *v4l2_ioctls[] = {
80 "QUERYCAP", "1", "ENUM_PIXFMT", "ENUM_FBUFFMT", "G_FMT", "S_FMT",
81 "G_COMP", "S_COMP", "REQBUFS", "QUERYBUF", "G_FBUF", "S_FBUF",
82 "G_WIN", "S_WIN", "PREVIEW", "QBUF", "16", "DQBUF", "STREAMON",
83 "STREAMOFF", "G_PERF", "G_PARM", "S_PARM", "G_STD", "S_STD",
84 "ENUMSTD", "ENUMINPUT", "G_CTRL", "S_CTRL", "G_TUNER", "S_TUNER",
85 "G_FREQ", "S_FREQ", "G_AUDIO", "S_AUDIO", "35", "QUERYCTRL",
86 "QUERYMENU", "G_INPUT", "S_INPUT", "ENUMCVT", "41", "42", "43",
87 "44", "45", "G_OUTPUT", "S_OUTPUT", "ENUMOUTPUT", "G_AUDOUT",
88 "S_AUDOUT", "ENUMFX", "G_EFFECT", "S_EFFECT", "G_MODULATOR",
91 #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)
93 void em2820_print_ioctl(char *name, unsigned int cmd)
97 switch (_IOC_DIR(cmd)) {
98 case _IOC_NONE: dir = "--"; break;
99 case _IOC_READ: dir = "r-"; break;
100 case _IOC_WRITE: dir = "-w"; break;
101 case _IOC_READ | _IOC_WRITE: dir = "rw"; break;
102 default: dir = "??"; break;
104 switch (_IOC_TYPE(cmd)) {
106 printk(KERN_DEBUG "%s: ioctl 0x%08x (v4l1, %s, VIDIOC%s)\n",
107 name, cmd, dir, (_IOC_NR(cmd) < V4L1_IOCTLS) ?
108 v4l1_ioctls[_IOC_NR(cmd)] : "???");
111 printk(KERN_DEBUG "%s: ioctl 0x%08x (v4l2, %s, VIDIOC_%s)\n",
112 name, cmd, dir, (_IOC_NR(cmd) < V4L2_IOCTLS) ?
113 v4l2_ioctls[_IOC_NR(cmd)] : "???");
116 printk(KERN_DEBUG "%s: ioctl 0x%08x (???, %s, #%d)\n",
117 name, cmd, dir, _IOC_NR(cmd));
121 static void *rvmalloc(size_t size)
126 size = PAGE_ALIGN(size);
128 mem = vmalloc_32((unsigned long)size);
132 memset(mem, 0, size);
134 adr = (unsigned long)mem;
136 SetPageReserved(vmalloc_to_page((void *)adr));
144 static void rvfree(void *mem, size_t size)
151 size = PAGE_ALIGN(size);
153 adr = (unsigned long)mem;
155 ClearPageReserved(vmalloc_to_page((void *)adr));
164 * em2820_request_buffers()
165 * allocate a number of buffers
167 u32 em2820_request_buffers(struct em2820 *dev, u32 count)
169 const size_t imagesize = PAGE_ALIGN(dev->frame_size); /*needs to be page aligned cause the buffers can be mapped individually! */
172 em2820_coredbg("requested %i buffers with size %i", count, imagesize);
173 if (count > EM2820_NUM_FRAMES)
174 count = EM2820_NUM_FRAMES;
176 dev->num_frames = count;
177 while (dev->num_frames > 0) {
178 if ((buff = rvmalloc(dev->num_frames * imagesize)))
183 for (i = 0; i < dev->num_frames; i++) {
184 dev->frame[i].bufmem = buff + i * imagesize;
185 dev->frame[i].buf.index = i;
186 dev->frame[i].buf.m.offset = i * imagesize;
187 dev->frame[i].buf.length = dev->frame_size;
188 dev->frame[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
189 dev->frame[i].buf.sequence = 0;
190 dev->frame[i].buf.field = V4L2_FIELD_NONE;
191 dev->frame[i].buf.memory = V4L2_MEMORY_MMAP;
192 dev->frame[i].buf.flags = 0;
194 return dev->num_frames;
198 * em2820_queue_unusedframes()
199 * add all frames that are not currently in use to the inbuffer queue
201 void em2820_queue_unusedframes(struct em2820 *dev)
203 unsigned long lock_flags;
206 for (i = 0; i < dev->num_frames; i++)
207 if (dev->frame[i].state == F_UNUSED) {
208 dev->frame[i].state = F_QUEUED;
209 spin_lock_irqsave(&dev->queue_lock, lock_flags);
210 list_add_tail(&dev->frame[i].frame, &dev->inqueue);
211 spin_unlock_irqrestore(&dev->queue_lock, lock_flags);
216 * em2820_release_buffers()
219 void em2820_release_buffers(struct em2820 *dev)
221 if (dev->num_frames) {
222 rvfree(dev->frame[0].bufmem,
223 dev->num_frames * PAGE_ALIGN(dev->frame[0].buf.length));
229 * em2820_read_reg_req()
230 * reads data from the usb device specifying bRequest
232 int em2820_read_reg_req_len(struct em2820 *dev, u8 req, u16 reg,
237 em2820_regdbg("req=%02x, reg=%02x ", req, reg);
239 ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,
240 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
241 0x0000, reg, buf, len, HZ);
244 printk(ret < 0 ? " failed!\n" : "%02x values: ", ret);
245 for (byte = 0; byte < len; byte++) {
246 printk(" %02x", buf[byte]);
255 * em2820_read_reg_req()
256 * reads data from the usb device specifying bRequest
258 int em2820_read_reg_req(struct em2820 *dev, u8 req, u16 reg)
263 em2820_regdbg("req=%02x, reg=%02x:", req, reg);
265 ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,
266 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
267 0x0000, reg, &val, 1, HZ);
270 printk(ret < 0 ? " failed!\n" : "%02x\n", val);
278 int em2820_read_reg(struct em2820 *dev, u16 reg)
280 return em2820_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
284 * em2820_write_regs_req()
285 * sends data to the usb device, specifying bRequest
287 int em2820_write_regs_req(struct em2820 *dev, u8 req, u16 reg, char *buf,
292 /*usb_control_msg seems to expect a kmalloced buffer */
293 unsigned char *bufs = kmalloc(len, GFP_KERNEL);
295 em2820_regdbg("req=%02x reg=%02x:", req, reg);
299 for (i = 0; i < len; ++i)
300 printk (" %02x", (unsigned char)buf[i]);
306 memcpy(bufs, buf, len);
307 ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), req,
308 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
309 0x0000, reg, bufs, len, HZ);
310 mdelay(5); /* FIXME: magic number */
315 int em2820_write_regs(struct em2820 *dev, u16 reg, char *buf, int len)
317 return em2820_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
321 * em2820_write_reg_bits()
322 * sets only some bits (specified by bitmask) of a register, by first reading
325 int em2820_write_reg_bits(struct em2820 *dev, u16 reg, u8 val,
330 if ((oldval = em2820_read_reg(dev, reg)) < 0)
332 newval = (((u8) oldval) & ~bitmask) | (val & bitmask);
333 return em2820_write_regs(dev, reg, &newval, 1);
337 * em2820_write_ac97()
338 * write a 16 bit value to the specified AC97 address (LSB first!)
340 int em2820_write_ac97(struct em2820 *dev, u8 reg, u8 * val)
343 u8 addr = reg & 0x7f;
344 if ((ret = em2820_write_regs(dev, AC97LSB_REG, val, 2)) < 0)
346 if ((ret = em2820_write_regs(dev, AC97ADDR_REG, &addr, 1)) < 0)
348 if ((ret = em2820_read_reg(dev, AC97BUSY_REG)) < 0)
350 else if (((u8) ret) & 0x01) {
351 em2820_warn ("AC97 command still being exectuted: not handled properly!\n");
356 int em2820_audio_analog_set(struct em2820 *dev)
358 char s[2] = { 0x00, 0x00 };
359 s[0] |= 0x1f - dev->volume;
360 s[1] |= 0x1f - dev->volume;
363 return em2820_write_ac97(dev, MASTER_AC97, s);
367 int em2820_colorlevels_set_default(struct em2820 *dev)
369 em2820_write_regs(dev, YGAIN_REG, "\x10", 1); /* contrast */
370 em2820_write_regs(dev, YOFFSET_REG, "\x00", 1); /* brightness */
371 em2820_write_regs(dev, UVGAIN_REG, "\x10", 1); /* saturation */
372 em2820_write_regs(dev, UOFFSET_REG, "\x00", 1);
373 em2820_write_regs(dev, VOFFSET_REG, "\x00", 1);
374 em2820_write_regs(dev, SHARPNESS_REG, "\x00", 1);
376 em2820_write_regs(dev, GAMMA_REG, "\x20", 1);
377 em2820_write_regs(dev, RGAIN_REG, "\x20", 1);
378 em2820_write_regs(dev, GGAIN_REG, "\x20", 1);
379 em2820_write_regs(dev, BGAIN_REG, "\x20", 1);
380 em2820_write_regs(dev, ROFFSET_REG, "\x00", 1);
381 em2820_write_regs(dev, GOFFSET_REG, "\x00", 1);
382 return em2820_write_regs(dev, BOFFSET_REG, "\x00", 1);
385 int em2820_capture_start(struct em2820 *dev, int start)
388 /* FIXME: which is the best order? */
389 /* video registers are sampled by VREF */
390 if ((ret = em2820_write_reg_bits(dev, USBSUSP_REG, start ? 0x10 : 0x00,
393 /* enable video capture */
394 return em2820_write_regs(dev, VINENABLE_REG, start ? "\x67" : "\x27", 1);
397 int em2820_outfmt_set_yuv422(struct em2820 *dev)
399 em2820_write_regs(dev, OUTFMT_REG, "\x34", 1);
400 em2820_write_regs(dev, VINMODE_REG, "\x10", 1);
401 return em2820_write_regs(dev, VINCTRL_REG, "\x11", 1);
404 int em2820_accumulator_set(struct em2820 *dev, u8 xmin, u8 xmax, u8 ymin,
407 em2820_coredbg("em2820 Scale: (%d,%d)-(%d,%d)\n", xmin, ymin, xmax, ymax);
409 em2820_write_regs(dev, XMIN_REG, &xmin, 1);
410 em2820_write_regs(dev, XMAX_REG, &xmax, 1);
411 em2820_write_regs(dev, YMIN_REG, &ymin, 1);
412 return em2820_write_regs(dev, YMAX_REG, &ymax, 1);
415 int em2820_capture_area_set(struct em2820 *dev, u8 hstart, u8 vstart,
416 u16 width, u16 height)
420 u8 overflow = (height >> 7 & 0x02) | (width >> 8 & 0x01);
422 em2820_coredbg("em2820 Area Set: (%d,%d)\n", (width | (overflow & 2) << 7),
423 (height | (overflow & 1) << 8));
425 em2820_write_regs(dev, HSTART_REG, &hstart, 1);
426 em2820_write_regs(dev, VSTART_REG, &vstart, 1);
427 em2820_write_regs(dev, CWIDTH_REG, &cwidth, 1);
428 em2820_write_regs(dev, CHEIGHT_REG, &cheight, 1);
429 return em2820_write_regs(dev, OFLOW_REG, &overflow, 1);
432 int em2820_scaler_set(struct em2820 *dev, u16 h, u16 v)
437 em2820_write_regs(dev, HSCALELOW_REG, (char *)buf, 2);
440 em2820_write_regs(dev, VSCALELOW_REG, (char *)buf, 2);
441 /* when H and V mixershould be used? */
442 /* return em2820_write_reg_bits(dev, COMPR_REG, (h ? 0x20 : 0x00) | (v ? 0x10 : 0x00), 0x30); */
443 /* it seems that both H and V scalers must be active to work correctly */
444 return em2820_write_reg_bits(dev, COMPR_REG, h
445 || v ? 0x30 : 0x00, 0x30);
448 /* FIXME: this only function read values from dev */
449 int em2820_resolution_set(struct em2820 *dev)
452 width = norm_maxw(dev);
453 height = norm_maxh(dev) >> 1;
455 em2820_outfmt_set_yuv422(dev);
456 em2820_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);
457 em2820_capture_area_set(dev, 0, 0, width >> 2, height >> 2);
458 return em2820_scaler_set(dev, dev->hscale, dev->vscale);
462 /******************* isoc transfer handling ****************************/
464 #ifdef ENABLE_DEBUG_ISOC_FRAMES
465 static void em2820_isoc_dump(struct urb *urb, struct pt_regs *regs)
471 printk(KERN_DEBUG "isocIrq: sf=%d np=%d ec=%x\n",
472 urb->start_frame, urb->number_of_packets,
474 for (i = 0; i < urb->number_of_packets; i++) {
476 urb->transfer_buffer +
477 urb->iso_frame_desc[i].offset;
478 int alen = urb->iso_frame_desc[i].actual_length;
480 if (buf[0] == 0x88) {
483 } else if (buf[0] == 0x22) {
485 "= l=%d nt=%d bpp=%d\n",
486 len - 4 * ntrans, ntrans,
487 ntrans == 0 ? 0 : len / ntrans);
491 printk(KERN_DEBUG "!\n");
493 printk(KERN_DEBUG " n=%d s=%d al=%d %x\n", i,
494 urb->iso_frame_desc[i].status,
495 urb->iso_frame_desc[i].actual_length,
497 *((unsigned char *)(urb->transfer_buffer +
498 urb->iso_frame_desc[i].
504 static inline int em2820_isoc_video(struct em2820 *dev,struct em2820_frame_t **f,
505 unsigned long *lock_flags, unsigned char buf)
508 if ((*f)->state == F_GRABBING) {
509 /*previous frame is incomplete */
510 if ((*f)->fieldbytesused < dev->field_size) {
511 (*f)->state = F_ERROR;
512 em2820_isocdbg ("dropping incomplete bottom field (%i missing bytes)",
513 dev->field_size-(*f)->fieldbytesused);
515 (*f)->state = F_DONE;
516 (*f)->buf.bytesused = dev->frame_size;
519 if ((*f)->state == F_DONE || (*f)->state == F_ERROR) {
520 /* move current frame to outqueue and get next free buffer from inqueue */
521 spin_lock_irqsave(&dev-> queue_lock, *lock_flags);
522 list_move_tail(&(*f)->frame, &dev->outqueue);
523 if (!list_empty(&dev->inqueue))
524 (*f) = list_entry(dev-> inqueue.next,
525 struct em2820_frame_t,frame);
528 spin_unlock_irqrestore(&dev->queue_lock,*lock_flags);
531 em2820_isocdbg ("new frame but no buffer is free");
534 do_gettimeofday(&(*f)->buf.timestamp);
535 (*f)->buf.sequence = ++dev->frame_count;
536 (*f)->buf.field = V4L2_FIELD_INTERLACED;
537 (*f)->state = F_GRABBING;
538 (*f)->buf.bytesused = 0;
540 (*f)->fieldbytesused = 0;
542 /* acquiring bottom field */
543 if ((*f)->state == F_GRABBING) {
544 if (!(*f)->top_field) {
545 (*f)->state = F_ERROR;
546 em2820_isocdbg ("unexpected begin of bottom field; discarding it");
547 } else if ((*f)-> fieldbytesused < dev->field_size - 172) {
548 (*f)->state = F_ERROR;
549 em2820_isocdbg ("dropping incomplete top field (%i missing bytes)",
550 dev->field_size-(*f)->fieldbytesused);
553 (*f)->fieldbytesused = 0;
560 static inline void em2820_isoc_video_copy(struct em2820 *dev,
561 struct em2820_frame_t **f, unsigned char *buf, int len)
563 void *fieldstart, *startwrite, *startread;
564 int linesdone, currlinedone, offset, lencopy,remain;
566 if ((*f)->fieldbytesused + len > dev->field_size)
567 len =dev->field_size - (*f)->fieldbytesused;
571 fieldstart = (*f)->bufmem;
573 fieldstart = (*f)->bufmem + dev->bytesperline;
575 linesdone = (*f)->fieldbytesused / dev->bytesperline;
576 currlinedone = (*f)->fieldbytesused % dev->bytesperline;
577 offset = linesdone * dev->bytesperline * 2 + currlinedone;
578 startwrite = fieldstart + offset;
579 lencopy = dev->bytesperline - currlinedone;
580 lencopy = lencopy > remain ? remain : lencopy;
582 memcpy(startwrite, startread, lencopy);
586 startwrite += lencopy + dev->bytesperline;
587 startread += lencopy;
588 if (dev->bytesperline > remain)
591 lencopy = dev->bytesperline;
593 memcpy(startwrite, startread, lencopy);
597 (*f)->fieldbytesused += len;
602 * handles the incoming isoc urbs and fills the frames from our inqueue
604 void em2820_isocIrq(struct urb *urb, struct pt_regs *regs)
606 struct em2820 *dev = urb->context;
608 struct em2820_frame_t **f;
609 unsigned long lock_flags;
613 #ifdef ENABLE_DEBUG_ISOC_FRAMES
615 em2820_isoc_dump(urb, regs);
618 if (urb->status == -ENOENT)
621 f = &dev->frame_current;
623 if (dev->stream == STREAM_INTERRUPT) {
624 dev->stream = STREAM_OFF;
626 (*f)->state = F_QUEUED;
627 em2820_isocdbg("stream interrupted");
628 wake_up_interruptible(&dev->wait_stream);
631 if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))
634 if (dev->stream == STREAM_ON && !list_empty(&dev->inqueue)) {
636 (*f) = list_entry(dev->inqueue.next,
637 struct em2820_frame_t, frame);
639 for (i = 0; i < urb->number_of_packets; i++) {
640 unsigned char *buf = urb->transfer_buffer +
641 urb->iso_frame_desc[i].offset;
642 int len = urb->iso_frame_desc[i].actual_length - 4;
644 if (urb->iso_frame_desc[i].status) {
645 em2820_isocdbg("data error: [%d] len=%d, status=%d", i,
646 urb->iso_frame_desc[i].actual_length,
647 urb->iso_frame_desc[i].status);
650 if (urb->iso_frame_desc[i].actual_length <= 0) {
651 em2820_isocdbg("packet %d is empty",i);
654 if (urb->iso_frame_desc[i].actual_length >
656 em2820_isocdbg("packet bigger than packet size");
660 if (buf[0] == 0x22 && buf[1] == 0x5a) {
661 em2820_isocdbg("Video frame, length=%i!",len);
663 if (em2820_isoc_video(dev,f,&lock_flags,buf[2]))
665 } else if (buf[0]==0x33 && buf[1]==0x95 && buf[2]==0x00) {
666 em2820_isocdbg("VBI HEADER!!!");
670 if ((*f)->state == F_GRABBING) {
671 em2820_isoc_video_copy(dev,f,buf, len);
676 for (i = 0; i < urb->number_of_packets; i++) {
677 urb->iso_frame_desc[i].status = 0;
678 urb->iso_frame_desc[i].actual_length = 0;
682 if ((status = usb_submit_urb(urb, GFP_ATOMIC))) {
683 em2820_errdev("resubmit of urb failed (error=%i)\n", status);
684 dev->state |= DEV_MISCONFIGURED;
686 wake_up_interruptible(&dev->wait_frame);
691 * em2820_uninit_isoc()
692 * deallocates the buffers and urbs allocated during em2820_init_iosc()
694 void em2820_uninit_isoc(struct em2820 *dev)
698 for (i = 0; i < EM2820_NUM_BUFS; i++) {
700 usb_kill_urb(dev->urb[i]);
701 usb_free_urb(dev->urb[i]);
704 if (dev->transfer_buffer[i])
705 kfree(dev->transfer_buffer[i]);
706 dev->transfer_buffer[i] = NULL;
708 em2820_capture_start(dev, 0);
713 * allocates transfer buffers and submits the urbs for isoc transfer
715 int em2820_init_isoc(struct em2820 *dev)
717 /* change interface to 3 which allowes the biggest packet sizes */
719 const int sb_size = EM2820_NUM_PACKETS * dev->max_pkt_size;
721 /* reset streaming vars */
722 dev->frame_current = NULL;
723 dev->frame_count = 0;
726 for (i = 0; i < EM2820_NUM_BUFS; i++) {
729 /* allocate transfer buffer */
730 dev->transfer_buffer[i] = kmalloc(sb_size, GFP_KERNEL);
731 if (!dev->transfer_buffer[i]) {
733 ("unable to allocate %i bytes for transfer buffer %i\n",
735 em2820_uninit_isoc(dev);
738 memset(dev->transfer_buffer[i], 0, sb_size);
739 urb = usb_alloc_urb(EM2820_NUM_PACKETS, GFP_KERNEL);
741 urb->dev = dev->udev;
743 urb->pipe = usb_rcvisocpipe(dev->udev, 0x82);
744 urb->transfer_flags = URB_ISO_ASAP;
746 urb->transfer_buffer = dev->transfer_buffer[i];
747 urb->complete = em2820_isocIrq;
748 urb->number_of_packets = EM2820_NUM_PACKETS;
749 urb->transfer_buffer_length = sb_size;
750 for (j = k = 0; j < EM2820_NUM_PACKETS;
751 j++, k += dev->max_pkt_size) {
752 urb->iso_frame_desc[j].offset = k;
753 urb->iso_frame_desc[j].length =
758 em2820_errdev("cannot alloc urb %i\n", i);
759 em2820_uninit_isoc(dev);
765 for (i = 0; i < EM2820_NUM_BUFS; i++) {
766 errCode = usb_submit_urb(dev->urb[i], GFP_KERNEL);
768 em2820_errdev("submit of urb %i failed (error=%i)\n", i,
770 em2820_uninit_isoc(dev);
778 int em2820_set_alternate(struct em2820 *dev)
780 int errCode, prev_alt = dev->alt;
784 unsigned int min_pkt_size = dev->field_size / 137; /* FIXME: empiric magic number */
785 em2820_coredbg("minimum isoc packet size: %u", min_pkt_size);
787 for (i = 1; i < EM2820_MAX_ALT; i += 2) /* FIXME: skip even alternate: why do they not work? */
788 if (dev->alt_max_pkt_size[i] >= min_pkt_size) {
794 if (dev->alt != prev_alt) {
795 dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];
796 em2820_coredbg("setting alternate %d with wMaxPacketSize=%u", dev->alt,
798 errCode = usb_set_interface(dev->udev, 0, dev->alt);
801 ("cannot change alternate number to %d (error=%i)\n",