/*

    em28xx-core.c - driver for Empia EM2800/EM2820/2840 USB video capture devices

    Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>

 		      Markus Rechberger <mrechberger@gmail.com>

 		      Mauro Carvalho Chehab <mchehab@brturbo.com.br>

 		      Sascha Sommer <saschasommer@freenet.de>

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

  */

 #include <linux/init.h>

 #include <linux/list.h>

 #include <linux/module.h>

 #include <linux/moduleparam.h>

 #include <linux/usb.h>

 #include <linux/vmalloc.h>

 #include "em28xx.h"

 /* #define ENABLE_DEBUG_ISOC_FRAMES */

 static unsigned int core_debug = 0;

 module_param(core_debug,int,0644);

 MODULE_PARM_DESC(core_debug,"enable debug messages [core]");

 #define em28xx_coredbg(fmt, arg...) do {\

 	if (core_debug) \

 		printk(KERN_INFO "%s %s :"fmt, \

 			 dev->name, __FUNCTION__ , ##arg); } while (0)

 static unsigned int reg_debug = 0;

 module_param(reg_debug,int,0644);

 MODULE_PARM_DESC(reg_debug,"enable debug messages [URB reg]");

 #define em28xx_regdbg(fmt, arg...) do {\

 	if (reg_debug) \

 		printk(KERN_INFO "%s %s :"fmt, \

 			 dev->name, __FUNCTION__ , ##arg); } while (0)

 static unsigned int isoc_debug = 0;

 module_param(isoc_debug,int,0644);

 MODULE_PARM_DESC(isoc_debug,"enable debug messages [isoc transfers]");

 #define em28xx_isocdbg(fmt, arg...) do {\

 	if (isoc_debug) \

 		printk(KERN_INFO "%s %s :"fmt, \

 			 dev->name, __FUNCTION__ , ##arg); } while (0)

 static int alt = EM28XX_PINOUT;

 module_param(alt, int, 0644);

 MODULE_PARM_DESC(alt, "alternate setting to use for video endpoint");

 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)

 static void *rvmalloc(size_t size)

 {

 	void *mem;

 	unsigned long adr;

 	size = PAGE_ALIGN(size);

 	mem = vmalloc_32((unsigned long)size);

 	if (!mem)

 		return NULL;

 	adr = (unsigned long)mem;

 	while (size > 0) {

 		SetPageReserved(vmalloc_to_page((void *)adr));

 		adr += PAGE_SIZE;

 		size -= PAGE_SIZE;

 	}

 	return mem;

 }

 static void rvfree(void *mem, size_t size)

 {

 	unsigned long adr;

 	if (!mem)

 		return;

 	size = PAGE_ALIGN(size);

 	adr = (unsigned long)mem;

 	while (size > 0) {

 		ClearPageReserved(vmalloc_to_page((void *)adr));

 		adr += PAGE_SIZE;

 		size -= PAGE_SIZE;

 	}

 	vfree(mem);

 }

 #endif

 /*

  * em28xx_request_buffers()

  * allocate a number of buffers

  */

 u32 em28xx_request_buffers(struct em28xx *dev, u32 count)

 {

 	const size_t imagesize = PAGE_ALIGN(dev->frame_size);	/*needs to be page aligned cause the buffers can be mapped individually! */

 	void *buff = NULL;

 	u32 i;

 	em28xx_coredbg("requested %i buffers with size %zi", count, imagesize);

 	if (count > EM28XX_NUM_FRAMES)

 		count = EM28XX_NUM_FRAMES;

 	dev->num_frames = count;

 	while (dev->num_frames > 0) {

 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)

 		if ((buff = rvmalloc(dev->num_frames * imagesize))) {

 #else

 		if ((buff = vmalloc_32(dev->num_frames * imagesize))) {

 #endif

 			memset(buff, 0, dev->num_frames * imagesize);

 			break;

 		}

 		dev->num_frames--;

 	}

 	for (i = 0; i < dev->num_frames; i++) {

 		dev->frame[i].bufmem = buff + i * imagesize;

 		dev->frame[i].buf.index = i;

 		dev->frame[i].buf.m.offset = i * imagesize;

 		dev->frame[i].buf.length = dev->frame_size;

 		dev->frame[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

 		dev->frame[i].buf.sequence = 0;

 		dev->frame[i].buf.field = V4L2_FIELD_NONE;

 		dev->frame[i].buf.memory = V4L2_MEMORY_MMAP;

 		dev->frame[i].buf.flags = 0;

 	}

 	return dev->num_frames;

 }

 /*

  * em28xx_queue_unusedframes()

  * add all frames that are not currently in use to the inbuffer queue

  */

 void em28xx_queue_unusedframes(struct em28xx *dev)

 {

 	unsigned long lock_flags;

 	u32 i;

 	for (i = 0; i < dev->num_frames; i++)

 		if (dev->frame[i].state == F_UNUSED) {

 			dev->frame[i].state = F_QUEUED;

 			spin_lock_irqsave(&dev->queue_lock, lock_flags);

 			list_add_tail(&dev->frame[i].frame, &dev->inqueue);

 			spin_unlock_irqrestore(&dev->queue_lock, lock_flags);

 		}

 }

 /*

  * em28xx_release_buffers()

  * free frame buffers

  */

 void em28xx_release_buffers(struct em28xx *dev)

 {

 	if (dev->num_frames) {

 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15)

 		rvfree(dev->frame[0].bufmem,

 		       dev->num_frames * PAGE_ALIGN(dev->frame[0].buf.length));

 #else

 		vfree(dev->frame[0].bufmem);

 #endif

 		dev->num_frames = 0;

 	}

 }

 /*

  * em28xx_read_reg_req()

  * reads data from the usb device specifying bRequest

  */

 int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16 reg,

 				   char *buf, int len)

 {

 	int ret, byte;

 	if (dev->state & DEV_DISCONNECTED)

 		return(-ENODEV);

 	em28xx_regdbg("req=%02x, reg=%02x ", req, reg);

 	ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,

 			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

 			      0x0000, reg, buf, len, HZ);

 	if (reg_debug){

 		printk(ret < 0 ? " failed!\n" : "%02x values: ", ret);

 		for (byte = 0; byte < len; byte++) {

 			printk(" %02x", buf[byte]);

 		}

 		printk("\n");

 	}

 	return ret;

 }

 /*

  * em28xx_read_reg_req()

  * reads data from the usb device specifying bRequest

  */

 int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg)

 {

 	u8 val;

 	int ret;

 	if (dev->state & DEV_DISCONNECTED)

 		return(-ENODEV);

 	em28xx_regdbg("req=%02x, reg=%02x:", req, reg);

 	ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0), req,

 			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

 			      0x0000, reg, &val, 1, HZ);

 	if (reg_debug)

 		printk(ret < 0 ? " failed!\n" : "%02x\n", val);

 	if (ret < 0)

 		return ret;

 	return val;

 }

 int em28xx_read_reg(struct em28xx *dev, u16 reg)

 {

 	return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);

 }

 /*

  * em28xx_write_regs_req()

  * sends data to the usb device, specifying bRequest

  */

 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,

 				 int len)

 {

 	int ret;

 	/*usb_control_msg seems to expect a kmalloced buffer */

 	unsigned char *bufs;

 	if (dev->state & DEV_DISCONNECTED)

 		return(-ENODEV);

 	bufs = kmalloc(len, GFP_KERNEL);

 	em28xx_regdbg("req=%02x reg=%02x:", req, reg);

 	if (reg_debug) {

 		int i;

 		for (i = 0; i < len; ++i)

 			printk (" %02x", (unsigned char)buf[i]);

 		printk ("\n");

 	}

 	if (!bufs)

 		return -ENOMEM;

 	memcpy(bufs, buf, len);

 	ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0), req,

 			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

 			      0x0000, reg, bufs, len, HZ);

 	msleep(5);		/* FIXME: magic number */

 	kfree(bufs);

 	return ret;

 }

 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)

 {

 	return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);

 }

 /*

  * em28xx_write_reg_bits()

  * sets only some bits (specified by bitmask) of a register, by first reading

  * the actual value

  */

 int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,

 				 u8 bitmask)

 {

 	int oldval;

 	u8 newval;

 	if ((oldval = em28xx_read_reg(dev, reg)) < 0)

 		return oldval;

 	newval = (((u8) oldval) & ~bitmask) | (val & bitmask);

 	return em28xx_write_regs(dev, reg, &newval, 1);

 }

 /*

  * em28xx_write_ac97()

  * write a 16 bit value to the specified AC97 address (LSB first!)

  */

 int em28xx_write_ac97(struct em28xx *dev, u8 reg, u8 * val)

 {

 	int ret;

 	u8 addr = reg & 0x7f;

 	if ((ret = em28xx_write_regs(dev, AC97LSB_REG, val, 2)) < 0)

 		return ret;

 	if ((ret = em28xx_write_regs(dev, AC97ADDR_REG, &addr, 1)) < 0)

 		return ret;

 	if ((ret = em28xx_read_reg(dev, AC97BUSY_REG)) < 0)

 		return ret;

 	else if (((u8) ret) & 0x01) {

 		em28xx_warn ("AC97 command still being executed: not handled properly!\n");

 	}

 	return 0;

 }

 int em28xx_audio_analog_set(struct em28xx *dev)

 {

 	char s[2] = { 0x00, 0x00 };

 	s[0] |= 0x1f - dev->volume;

 	s[1] |= 0x1f - dev->volume;

 	if (dev->mute)

 		s[1] |= 0x80;

 	return em28xx_write_ac97(dev, MASTER_AC97, s);

 }

 #if 0

 int em28xx_audio_analog_mute(struct em28xx *dev, int mute)

 {

 	/* (un)mute master mixer with maximum volume level */

 	return em28xx_write_ac97(dev, MASTER_AC97,

 				 mute ? "\x00\x80" : "\x00\x00");

 }

 #endif

 int em28xx_colorlevels_set_default(struct em28xx *dev)

 {

 	em28xx_write_regs(dev, YGAIN_REG, "\x10", 1);	/* contrast */

 	em28xx_write_regs(dev, YOFFSET_REG, "\x00", 1);	/* brightness */

 	em28xx_write_regs(dev, UVGAIN_REG, "\x10", 1);	/* saturation */

 	em28xx_write_regs(dev, UOFFSET_REG, "\x00", 1);

 	em28xx_write_regs(dev, VOFFSET_REG, "\x00", 1);

 	em28xx_write_regs(dev, SHARPNESS_REG, "\x00", 1);

 	em28xx_write_regs(dev, GAMMA_REG, "\x20", 1);

 	em28xx_write_regs(dev, RGAIN_REG, "\x20", 1);

 	em28xx_write_regs(dev, GGAIN_REG, "\x20", 1);

 	em28xx_write_regs(dev, BGAIN_REG, "\x20", 1);

 	em28xx_write_regs(dev, ROFFSET_REG, "\x00", 1);

 	em28xx_write_regs(dev, GOFFSET_REG, "\x00", 1);

 	return em28xx_write_regs(dev, BOFFSET_REG, "\x00", 1);

 }

 int em28xx_capture_start(struct em28xx *dev, int start)

 {

 	int ret;

 	/* FIXME: which is the best order? */

 	/* video registers are sampled by VREF */

 	if ((ret = em28xx_write_reg_bits(dev, USBSUSP_REG, start ? 0x10 : 0x00,

 					  0x10)) < 0)

 		return ret;

 	/* enable video capture */

 	return em28xx_write_regs(dev, VINENABLE_REG, start ? "\x67" : "\x27", 1);

 }

 int em28xx_outfmt_set_yuv422(struct em28xx *dev)

 {

 	em28xx_write_regs(dev, OUTFMT_REG, "\x34", 1);

 	em28xx_write_regs(dev, VINMODE_REG, "\x10", 1);

 	return em28xx_write_regs(dev, VINCTRL_REG, "\x11", 1);

 }

 int em28xx_accumulator_set(struct em28xx *dev, u8 xmin, u8 xmax, u8 ymin,

 				  u8 ymax)

 {

 	em28xx_coredbg("em28xx Scale: (%d,%d)-(%d,%d)\n", xmin, ymin, xmax, ymax);

 	em28xx_write_regs(dev, XMIN_REG, &xmin, 1);

 	em28xx_write_regs(dev, XMAX_REG, &xmax, 1);

 	em28xx_write_regs(dev, YMIN_REG, &ymin, 1);

 	return em28xx_write_regs(dev, YMAX_REG, &ymax, 1);

 }

 int em28xx_capture_area_set(struct em28xx *dev, u8 hstart, u8 vstart,

 				   u16 width, u16 height)

 {

 	u8 cwidth = width;

 	u8 cheight = height;

 	u8 overflow = (height >> 7 & 0x02) | (width >> 8 & 0x01);

 	em28xx_coredbg("em28xx Area Set: (%d,%d)\n", (width | (overflow & 2) << 7),

 			(height | (overflow & 1) << 8));

 	em28xx_write_regs(dev, HSTART_REG, &hstart, 1);

 	em28xx_write_regs(dev, VSTART_REG, &vstart, 1);

 	em28xx_write_regs(dev, CWIDTH_REG, &cwidth, 1);

 	em28xx_write_regs(dev, CHEIGHT_REG, &cheight, 1);

 	return em28xx_write_regs(dev, OFLOW_REG, &overflow, 1);

 }

 int em28xx_scaler_set(struct em28xx *dev, u16 h, u16 v)

 {

 	u8 mode;

 	/* the em2800 scaler only supports scaling down to 50% */

 	if(dev->is_em2800)

 		mode = (v ? 0x20 : 0x00) | (h ? 0x10 : 0x00);

 	else {

 		u8 buf[2];

 		buf[0] = h;

 		buf[1] = h >> 8;

 		em28xx_write_regs(dev, HSCALELOW_REG, (char *)buf, 2);

 		buf[0] = v;

 		buf[1] = v >> 8;

 		em28xx_write_regs(dev, VSCALELOW_REG, (char *)buf, 2);

 		/* it seems that both H and V scalers must be active to work correctly */

 		mode = (h || v)? 0x30: 0x00;

 	}

 	return em28xx_write_reg_bits(dev, COMPR_REG, mode, 0x30);

 }

 /* FIXME: this only function read values from dev */

 int em28xx_resolution_set(struct em28xx *dev)

 {

 	int width, height;

 	width = norm_maxw(dev);

 	height = norm_maxh(dev) >> 1;

 	em28xx_outfmt_set_yuv422(dev);

 	em28xx_accumulator_set(dev, 1, (width - 4) >> 2, 1, (height - 4) >> 2);

 	em28xx_capture_area_set(dev, 0, 0, width >> 2, height >> 2);

 	return em28xx_scaler_set(dev, dev->hscale, dev->vscale);

 }

 /******************* isoc transfer handling ****************************/

 #ifdef ENABLE_DEBUG_ISOC_FRAMES

 static void em28xx_isoc_dump(struct urb *urb, struct pt_regs *regs)

 {

 	int len = 0;

 	int ntrans = 0;

 	int i;

 	printk(KERN_DEBUG "isocIrq: sf=%d np=%d ec=%x\n",

 	       urb->start_frame, urb->number_of_packets,

 	       urb->error_count);

 	for (i = 0; i < urb->number_of_packets; i++) {

 		unsigned char *buf =

 				urb->transfer_buffer +

 				urb->iso_frame_desc[i].offset;

 		int alen = urb->iso_frame_desc[i].actual_length;

 		if (alen > 0) {

 			if (buf[0] == 0x88) {

 				ntrans++;

 				len += alen;

 			} else if (buf[0] == 0x22) {

 				printk(KERN_DEBUG

 						"= l=%d nt=%d bpp=%d\n",

 				len - 4 * ntrans, ntrans,

 				ntrans == 0 ? 0 : len / ntrans);

 				ntrans = 1;

 				len = alen;

 			} else

 				printk(KERN_DEBUG "!\n");

 		}

 		printk(KERN_DEBUG "   n=%d s=%d al=%d %x\n", i,

 		       urb->iso_frame_desc[i].status,

 		       urb->iso_frame_desc[i].actual_length,

 		       (unsigned int)

 				       *((unsigned char *)(urb->transfer_buffer +

 				       urb->iso_frame_desc[i].

 				       offset)));

 	}

 }

 #endif

 static inline int em28xx_isoc_video(struct em28xx *dev,struct em28xx_frame_t **f,

 				    unsigned long *lock_flags, unsigned char buf)

 {

 	if (!(buf & 0x01)) {

 		if ((*f)->state == F_GRABBING) {

 			/*previous frame is incomplete */

 			if ((*f)->fieldbytesused < dev->field_size) {

 				(*f)->state = F_ERROR;

 				em28xx_isocdbg ("dropping incomplete bottom field (%i missing bytes)",

 					 dev->field_size-(*f)->fieldbytesused);

 			} else {

 				(*f)->state = F_DONE;

 				(*f)->buf.bytesused = dev->frame_size;

 			}

 		}

 		if ((*f)->state == F_DONE || (*f)->state == F_ERROR) {

 			/* move current frame to outqueue and get next free buffer from inqueue */

 			spin_lock_irqsave(&dev-> queue_lock, *lock_flags);

 			list_move_tail(&(*f)->frame, &dev->outqueue);

 			if (!list_empty(&dev->inqueue))

 				(*f) = list_entry(dev-> inqueue.next,

 			struct em28xx_frame_t,frame);

 			else

 				(*f) = NULL;

 			spin_unlock_irqrestore(&dev->queue_lock,*lock_flags);

 		}

 		if (!(*f)) {

 			em28xx_isocdbg ("new frame but no buffer is free");

 			return -1;

 		}

 		do_gettimeofday(&(*f)->buf.timestamp);

 		(*f)->buf.sequence = ++dev->frame_count;

 		(*f)->buf.field = V4L2_FIELD_INTERLACED;

 		(*f)->state = F_GRABBING;

 		(*f)->buf.bytesused = 0;

 		(*f)->top_field = 1;

 		(*f)->fieldbytesused = 0;

 	} else {

 					/* acquiring bottom field */

 		if ((*f)->state == F_GRABBING) {

 			if (!(*f)->top_field) {

 				(*f)->state = F_ERROR;

 				em28xx_isocdbg ("unexpected begin of bottom field; discarding it");

 			} else if ((*f)-> fieldbytesused < dev->field_size - 172) {

 				(*f)->state = F_ERROR;

 				em28xx_isocdbg ("dropping incomplete top field (%i missing bytes)",

 					 dev->field_size-(*f)->fieldbytesused);

 			} else {

 				(*f)->top_field = 0;

 				(*f)->fieldbytesused = 0;

 			}

 		}

 	}

 	return (0);

 }

 static inline void em28xx_isoc_video_copy(struct em28xx *dev,

 					  struct em28xx_frame_t **f, unsigned char *buf, int len)

 {

 	void *fieldstart, *startwrite, *startread;

 	int linesdone, currlinedone, offset, lencopy,remain;

 	if(dev->frame_size != (*f)->buf.length){

 		em28xx_err("frame_size %i and buf.length %i are different!!!\n",dev->frame_size,(*f)->buf.length);

 		return;

 	}

 	if ((*f)->fieldbytesused + len > dev->field_size)

 		len =dev->field_size - (*f)->fieldbytesused;

 	if (buf[0] != 0x88 && buf[0] != 0x22) {

 		em28xx_isocdbg("frame is not complete\n");

 		startread = buf;

 		len+=4;

 	} else

 		startread = buf + 4;

 	remain = len;

 	if ((*f)->top_field)

 		fieldstart = (*f)->bufmem;

 	else

 		fieldstart = (*f)->bufmem + dev->bytesperline;

 	linesdone = (*f)->fieldbytesused / dev->bytesperline;

 	currlinedone = (*f)->fieldbytesused % dev->bytesperline;

 	offset = linesdone * dev->bytesperline * 2 + currlinedone;

 	startwrite = fieldstart + offset;

 	lencopy = dev->bytesperline - currlinedone;

 	lencopy = lencopy > remain ? remain : lencopy;

 	memcpy(startwrite, startread, lencopy);

 	remain -= lencopy;

 	while (remain > 0) {

 		startwrite += lencopy + dev->bytesperline;

 		startread += lencopy;

 		if (dev->bytesperline > remain)

 			lencopy = remain;

 		else

 			lencopy = dev->bytesperline;

 		memcpy(startwrite, startread, lencopy);

 		remain -= lencopy;

 	}

 	(*f)->fieldbytesused += len;

 }

 /*

  * em28xx_isoIrq()

  * handles the incoming isoc urbs and fills the frames from our inqueue

  */

 void em28xx_isocIrq(struct urb *urb, struct pt_regs *regs)

 {

 	struct em28xx *dev = urb->context;

 	int i, status;

 	struct em28xx_frame_t **f;

 	unsigned long lock_flags;

 	if (!dev)

 		return;

 #ifdef ENABLE_DEBUG_ISOC_FRAMES

 	if (isoc_debug>1)

 		em28xx_isoc_dump(urb, regs);

 #endif

 	if (urb->status == -ENOENT)

 		return;

 	f = &dev->frame_current;

 	if (dev->stream == STREAM_INTERRUPT) {

 		dev->stream = STREAM_OFF;

 		if ((*f))

 			(*f)->state = F_QUEUED;

 		em28xx_isocdbg("stream interrupted");

 		wake_up_interruptible(&dev->wait_stream);

 	}

 	if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))

 		return;

 	if (dev->stream == STREAM_ON && !list_empty(&dev->inqueue)) {

 		if (!(*f))

 			(*f) = list_entry(dev->inqueue.next,

 		struct em28xx_frame_t, frame);

 		for (i = 0; i < urb->number_of_packets; i++) {

 			unsigned char *buf = urb->transfer_buffer +

 					urb->iso_frame_desc[i].offset;

 			int len = urb->iso_frame_desc[i].actual_length - 4;

 			if (urb->iso_frame_desc[i].status) {

 				em28xx_isocdbg("data error: [%d] len=%d, status=%d", i,

 					urb->iso_frame_desc[i].actual_length,

 					urb->iso_frame_desc[i].status);

 				if (urb->iso_frame_desc[i].status != -EPROTO)

 					continue;

 			}

 			if (urb->iso_frame_desc[i].actual_length <= 0) {

 				em28xx_isocdbg("packet %d is empty",i);

 				continue;

 			}

 			if (urb->iso_frame_desc[i].actual_length >

 						 dev->max_pkt_size) {

 				em28xx_isocdbg("packet bigger than packet size");

 				continue;

 			}

 			/*new frame */

 			if (buf[0] == 0x22 && buf[1] == 0x5a) {

 				em28xx_isocdbg("Video frame, length=%i!",len);

 				if (em28xx_isoc_video(dev,f,&lock_flags,buf[2]))

 				break;

 			} else if (buf[0]==0x33 && buf[1]==0x95 && buf[2]==0x00) {

 				em28xx_isocdbg("VBI HEADER!!!");

 			}

 			/* actual copying */

 			if ((*f)->state == F_GRABBING) {

 				em28xx_isoc_video_copy(dev,f,buf, len);

 			}

 		}

 	}

 	for (i = 0; i < urb->number_of_packets; i++) {

 		urb->iso_frame_desc[i].status = 0;

 		urb->iso_frame_desc[i].actual_length = 0;

 	}

 	urb->status = 0;

 	if ((status = usb_submit_urb(urb, GFP_ATOMIC))) {

 		em28xx_errdev("resubmit of urb failed (error=%i)\n", status);

 		dev->state |= DEV_MISCONFIGURED;

 	}

 	wake_up_interruptible(&dev->wait_frame);

 	return;

 }

 /*

  * em28xx_uninit_isoc()

  * deallocates the buffers and urbs allocated during em28xx_init_iosc()

  */

 void em28xx_uninit_isoc(struct em28xx *dev)

 {

 	int i;

 	for (i = 0; i < EM28XX_NUM_BUFS; i++) {

 		if (dev->urb[i]) {

 			usb_kill_urb(dev->urb[i]);

 			if (dev->transfer_buffer[i]){

 				usb_buffer_free(dev->udev,(EM28XX_NUM_PACKETS*dev->max_pkt_size),dev->transfer_buffer[i],dev->urb[i]->transfer_dma);

 			}

 			usb_free_urb(dev->urb[i]);

 		}

 		dev->urb[i] = NULL;

 		dev->transfer_buffer[i] = NULL;

 	}

 	em28xx_capture_start(dev, 0);

 }

 /*

  * em28xx_init_isoc()

  * allocates transfer buffers and submits the urbs for isoc transfer

  */

 int em28xx_init_isoc(struct em28xx *dev)

 {

 	/* change interface to 3 which allowes the biggest packet sizes */

 	int i, errCode;

 	const int sb_size = EM28XX_NUM_PACKETS * dev->max_pkt_size;

 	/* reset streaming vars */

 	dev->frame_current = NULL;

 	dev->frame_count = 0;

 	/* allocate urbs */

 	for (i = 0; i < EM28XX_NUM_BUFS; i++) {

 		struct urb *urb;

 		int j, k;

 		/* allocate transfer buffer */

 		urb = usb_alloc_urb(EM28XX_NUM_PACKETS, GFP_KERNEL);

 		if (!urb){

 			em28xx_errdev("cannot alloc urb %i\n", i);

 			em28xx_uninit_isoc(dev);

 			return -ENOMEM;

 		}

 		dev->transfer_buffer[i] = usb_buffer_alloc(dev->udev, sb_size, GFP_KERNEL,&urb->transfer_dma);

 		if (!dev->transfer_buffer[i]) {

 			em28xx_errdev

 					("unable to allocate %i bytes for transfer buffer %i\n",

 					 sb_size, i);

 			em28xx_uninit_isoc(dev);

 			return -ENOMEM;

 		}

 		memset(dev->transfer_buffer[i], 0, sb_size);

 		urb->dev = dev->udev;

 		urb->context = dev;

 		urb->pipe = usb_rcvisocpipe(dev->udev, 0x82);

 		urb->transfer_flags = URB_ISO_ASAP;

 		urb->interval = 1;

 		urb->transfer_buffer = dev->transfer_buffer[i];

 		urb->complete = em28xx_isocIrq;

 		urb->number_of_packets = EM28XX_NUM_PACKETS;

 		urb->transfer_buffer_length = sb_size;

 		for (j = k = 0; j < EM28XX_NUM_PACKETS;

 				j++, k += dev->max_pkt_size) {

 			urb->iso_frame_desc[j].offset = k;

 			urb->iso_frame_desc[j].length =

 				dev->max_pkt_size;

 		}

 		dev->urb[i] = urb;

 	}

 	/* submit urbs */

 	for (i = 0; i < EM28XX_NUM_BUFS; i++) {

 		errCode = usb_submit_urb(dev->urb[i], GFP_KERNEL);

 		if (errCode) {

 			em28xx_errdev("submit of urb %i failed (error=%i)\n", i,

 				      errCode);

 			em28xx_uninit_isoc(dev);

 			return errCode;

 		}

 	}

 	return 0;

 }

 int em28xx_set_alternate(struct em28xx *dev)

 {

 	int errCode, prev_alt = dev->alt;

 	dev->alt = alt;

 	if (dev->alt == 0) {

 		int i;

 #if 1 /* Always try to get the maximum size value */

 		for(i=0;i< dev->num_alt; i++)

 			if(dev->alt_max_pkt_size[i]>dev->alt_max_pkt_size[dev->alt])

 				dev->alt=i;

 #endif

 #if 0 /* Should be dependent of horizontal size */

 		if(dev->is_em2800){ /* always use the max packet size for em2800 based devices */

 			for(i=0;i< dev->num_alt; i++)

 				if(dev->alt_max_pkt_size[i]>dev->alt_max_pkt_size[dev->alt])

 					dev->alt=i;

 		}else{

 		unsigned int min_pkt_size = dev->field_size / 137;	/* FIXME: empiric magic number */

 		em28xx_coredbg("minimum isoc packet size: %u", min_pkt_size);

 		dev->alt = 7;

 		for (i = 0; i < dev->num_alt; i ++)

 			if (dev->alt_max_pkt_size[i] >= min_pkt_size) {

 			dev->alt = i;

 			break;

 			}

 		}

 #endif

 	}

 	if (dev->alt != prev_alt) {

 		dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];

 		em28xx_coredbg("setting alternate %d with wMaxPacketSize=%u\n", dev->alt,

 		       dev->max_pkt_size);

 		errCode = usb_set_interface(dev->udev, 0, dev->alt);

 		if (errCode < 0) {

 			em28xx_errdev ("cannot change alternate number to %d (error=%i)\n",

 							dev->alt, errCode);

 			return errCode;

 		}

 	}

 	return 0;

 }