/*
 * usbvision-core.c - driver for NT100x USB video capture devices
 *
 *
 * Copyright (c) 1999-2005 Joerg Heckenbach <joerg@heckenbach-aw.de>
 *                         Dwaine Garden <dwainegarden@rogers.com>
 *
 * This module is part of usbvision driver project.
 * Updates to driver completed by Dwaine P. Garden
 *
 * 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/kernel.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/videodev2.h>
#include <linux/i2c.h>

#include <media/i2c/saa7115.h>
#include <media/v4l2-common.h>
#include <media/tuner.h>

#include <linux/workqueue.h>

#include "usbvision.h"

static unsigned int core_debug;
module_param(core_debug, int, 0644);
MODULE_PARM_DESC(core_debug, "enable debug messages [core]");

static int adjust_compression = 1;      /* Set the compression to be adaptive */
module_param(adjust_compression, int, 0444);
MODULE_PARM_DESC(adjust_compression, " Set the ADPCM compression for the device.  Default: 1 (On)");

/* To help people with Black and White output with using s-video input.
 * Some cables and input device are wired differently. */
static int switch_svideo_input;
module_param(switch_svideo_input, int, 0444);
MODULE_PARM_DESC(switch_svideo_input, " Set the S-Video input.  Some cables and input device are wired differently. Default: 0 (Off)");

static unsigned int adjust_x_offset = -1;
module_param(adjust_x_offset, int, 0644);
MODULE_PARM_DESC(adjust_x_offset, "adjust X offset display [core]");

static unsigned int adjust_y_offset = -1;
module_param(adjust_y_offset, int, 0644);
MODULE_PARM_DESC(adjust_y_offset, "adjust Y offset display [core]");


#define ENABLE_HEXDUMP  0       /* Enable if you need it */


#ifdef USBVISION_DEBUG
        #define PDEBUG(level, fmt, args...) { \
                if (core_debug & (level)) \
                        printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
                                __func__, __LINE__ , ## args); \
        }
#else
        #define PDEBUG(level, fmt, args...) do {} while (0)
#endif

#define DBG_HEADER      (1 << 0)
#define DBG_IRQ         (1 << 1)
#define DBG_ISOC        (1 << 2)
#define DBG_PARSE       (1 << 3)
#define DBG_SCRATCH     (1 << 4)
#define DBG_FUNC        (1 << 5)

/* The value of 'scratch_buf_size' affects quality of the picture
 * in many ways. Shorter buffers may cause loss of data when client
 * is too slow. Larger buffers are memory-consuming and take longer
 * to work with. This setting can be adjusted, but the default value
 * should be OK for most desktop users.
 */
#define DEFAULT_SCRATCH_BUF_SIZE        (0x20000)               /* 128kB memory scratch buffer */
static const int scratch_buf_size = DEFAULT_SCRATCH_BUF_SIZE;

/* Function prototypes */
static int usbvision_request_intra(struct usb_usbvision *usbvision);
static int usbvision_unrequest_intra(struct usb_usbvision *usbvision);
static int usbvision_adjust_compression(struct usb_usbvision *usbvision);
static int usbvision_measure_bandwidth(struct usb_usbvision *usbvision);

/*******************************/
/* Memory management functions */
/*******************************/

/*
 * Here we want the physical address of the memory.
 * This is used when initializing the contents of the area.
 */

static void *usbvision_rvmalloc(unsigned long size)
{
        void *mem;
        unsigned long adr;

        size = PAGE_ALIGN(size);
        mem = vmalloc_32(size);
        if (!mem)
                return NULL;

        memset(mem, 0, size); /* Clear the ram out, no junk to the user */
        adr = (unsigned long) mem;
        while (size > 0) {
                SetPageReserved(vmalloc_to_page((void *)adr));
                adr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }

        return mem;
}

static void usbvision_rvfree(void *mem, unsigned long size)
{
        unsigned long adr;

        if (!mem)
                return;

        size = PAGE_ALIGN(size);

        adr = (unsigned long) mem;
        while ((long) size > 0) {
                ClearPageReserved(vmalloc_to_page((void *)adr));
                adr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }

        vfree(mem);
}


#if ENABLE_HEXDUMP
static void usbvision_hexdump(const unsigned char *data, int len)
{
        char tmp[80];
        int i, k;

        for (i = k = 0; len > 0; i++, len--) {
                if (i > 0 && (i % 16 == 0)) {
                        printk("%s\n", tmp);
                        k = 0;
                }
                k += sprintf(&tmp[k], "%02x ", data[i]);
        }
        if (k > 0)
                printk(KERN_CONT "%s\n", tmp);
}
#endif

/********************************
 * scratch ring buffer handling
 ********************************/
static int scratch_len(struct usb_usbvision *usbvision)    /* This returns the amount of data actually in the buffer */
{
        int len = usbvision->scratch_write_ptr - usbvision->scratch_read_ptr;

        if (len < 0)
                len += scratch_buf_size;
        PDEBUG(DBG_SCRATCH, "scratch_len() = %d\n", len);

        return len;
}


/* This returns the free space left in the buffer */
static int scratch_free(struct usb_usbvision *usbvision)
{
        int free = usbvision->scratch_read_ptr - usbvision->scratch_write_ptr;
        if (free <= 0)
                free += scratch_buf_size;
        if (free) {
                free -= 1;                                                      /* at least one byte in the buffer must */
                                                                                /* left blank, otherwise there is no chance to differ between full and empty */
        }
        PDEBUG(DBG_SCRATCH, "return %d\n", free);

        return free;
}


/* This puts data into the buffer */
static int scratch_put(struct usb_usbvision *usbvision, unsigned char *data,
                       int len)
{
        int len_part;

        if (usbvision->scratch_write_ptr + len < scratch_buf_size) {
                memcpy(usbvision->scratch + usbvision->scratch_write_ptr, data, len);
                usbvision->scratch_write_ptr += len;
        } else {
                len_part = scratch_buf_size - usbvision->scratch_write_ptr;
                memcpy(usbvision->scratch + usbvision->scratch_write_ptr, data, len_part);
                if (len == len_part) {
                        usbvision->scratch_write_ptr = 0;                       /* just set write_ptr to zero */
                } else {
                        memcpy(usbvision->scratch, data + len_part, len - len_part);
                        usbvision->scratch_write_ptr = len - len_part;
                }
        }

        PDEBUG(DBG_SCRATCH, "len=%d, new write_ptr=%d\n", len, usbvision->scratch_write_ptr);

        return len;
}

/* This marks the write_ptr as position of new frame header */
static void scratch_mark_header(struct usb_usbvision *usbvision)
{
        PDEBUG(DBG_SCRATCH, "header at write_ptr=%d\n", usbvision->scratch_headermarker_write_ptr);

        usbvision->scratch_headermarker[usbvision->scratch_headermarker_write_ptr] =
                                usbvision->scratch_write_ptr;
        usbvision->scratch_headermarker_write_ptr += 1;
        usbvision->scratch_headermarker_write_ptr %= USBVISION_NUM_HEADERMARKER;
}

/* This gets data from the buffer at the given "ptr" position */
static int scratch_get_extra(struct usb_usbvision *usbvision,
                             unsigned char *data, int *ptr, int len)
{
        int len_part;

        if (*ptr + len < scratch_buf_size) {
                memcpy(data, usbvision->scratch + *ptr, len);
                *ptr += len;
        } else {
                len_part = scratch_buf_size - *ptr;
                memcpy(data, usbvision->scratch + *ptr, len_part);
                if (len == len_part) {
                        *ptr = 0;                                                       /* just set the y_ptr to zero */
                } else {
                        memcpy(data + len_part, usbvision->scratch, len - len_part);
                        *ptr = len - len_part;
                }
        }

        PDEBUG(DBG_SCRATCH, "len=%d, new ptr=%d\n", len, *ptr);

        return len;
}


/* This sets the scratch extra read pointer */
static void scratch_set_extra_ptr(struct usb_usbvision *usbvision, int *ptr,
                                  int len)
{
        *ptr = (usbvision->scratch_read_ptr + len) % scratch_buf_size;

        PDEBUG(DBG_SCRATCH, "ptr=%d\n", *ptr);
}


/* This increments the scratch extra read pointer */
static void scratch_inc_extra_ptr(int *ptr, int len)
{
        *ptr = (*ptr + len) % scratch_buf_size;

        PDEBUG(DBG_SCRATCH, "ptr=%d\n", *ptr);
}


/* This gets data from the buffer */
static int scratch_get(struct usb_usbvision *usbvision, unsigned char *data,
                       int len)
{
        int len_part;

        if (usbvision->scratch_read_ptr + len < scratch_buf_size) {
                memcpy(data, usbvision->scratch + usbvision->scratch_read_ptr, len);
                usbvision->scratch_read_ptr += len;
        } else {
                len_part = scratch_buf_size - usbvision->scratch_read_ptr;
                memcpy(data, usbvision->scratch + usbvision->scratch_read_ptr, len_part);
                if (len == len_part) {
                        usbvision->scratch_read_ptr = 0;                                /* just set the read_ptr to zero */
                } else {
                        memcpy(data + len_part, usbvision->scratch, len - len_part);
                        usbvision->scratch_read_ptr = len - len_part;
                }
        }

        PDEBUG(DBG_SCRATCH, "len=%d, new read_ptr=%d\n", len, usbvision->scratch_read_ptr);

        return len;
}


/* This sets read pointer to next header and returns it */
static int scratch_get_header(struct usb_usbvision *usbvision,
                              struct usbvision_frame_header *header)
{
        int err_code = 0;

        PDEBUG(DBG_SCRATCH, "from read_ptr=%d", usbvision->scratch_headermarker_read_ptr);

        while (usbvision->scratch_headermarker_write_ptr -
                usbvision->scratch_headermarker_read_ptr != 0) {
                usbvision->scratch_read_ptr =
                        usbvision->scratch_headermarker[usbvision->scratch_headermarker_read_ptr];
                usbvision->scratch_headermarker_read_ptr += 1;
                usbvision->scratch_headermarker_read_ptr %= USBVISION_NUM_HEADERMARKER;
                scratch_get(usbvision, (unsigned char *)header, USBVISION_HEADER_LENGTH);
                if ((header->magic_1 == USBVISION_MAGIC_1)
                         && (header->magic_2 == USBVISION_MAGIC_2)
                         && (header->header_length == USBVISION_HEADER_LENGTH)) {
                        err_code = USBVISION_HEADER_LENGTH;
                        header->frame_width  = header->frame_width_lo  + (header->frame_width_hi << 8);
                        header->frame_height = header->frame_height_lo + (header->frame_height_hi << 8);
                        break;
                }
        }

        return err_code;
}


/* This removes len bytes of old data from the buffer */
static void scratch_rm_old(struct usb_usbvision *usbvision, int len)
{
        usbvision->scratch_read_ptr += len;
        usbvision->scratch_read_ptr %= scratch_buf_size;
        PDEBUG(DBG_SCRATCH, "read_ptr is now %d\n", usbvision->scratch_read_ptr);
}


/* This resets the buffer - kills all data in it too */
static void scratch_reset(struct usb_usbvision *usbvision)
{
        PDEBUG(DBG_SCRATCH, "\n");

        usbvision->scratch_read_ptr = 0;
        usbvision->scratch_write_ptr = 0;
        usbvision->scratch_headermarker_read_ptr = 0;
        usbvision->scratch_headermarker_write_ptr = 0;
        usbvision->isocstate = isoc_state_no_frame;
}

int usbvision_scratch_alloc(struct usb_usbvision *usbvision)
{
        usbvision->scratch = vmalloc_32(scratch_buf_size);
        scratch_reset(usbvision);
        if (usbvision->scratch == NULL) {
                dev_err(&usbvision->dev->dev,
                        "%s: unable to allocate %d bytes for scratch\n",
                                __func__, scratch_buf_size);
                return -ENOMEM;
        }
        return 0;
}

void usbvision_scratch_free(struct usb_usbvision *usbvision)
{
        vfree(usbvision->scratch);
        usbvision->scratch = NULL;
}

/*
 * usbvision_decompress_alloc()
 *
 * allocates intermediate buffer for decompression
 */
int usbvision_decompress_alloc(struct usb_usbvision *usbvision)
{
        int IFB_size = MAX_FRAME_WIDTH * MAX_FRAME_HEIGHT * 3 / 2;

        usbvision->intra_frame_buffer = vmalloc_32(IFB_size);
        if (usbvision->intra_frame_buffer == NULL) {
                dev_err(&usbvision->dev->dev,
                        "%s: unable to allocate %d for compr. frame buffer\n",
                                __func__, IFB_size);
                return -ENOMEM;
        }
        return 0;
}

/*
 * usbvision_decompress_free()
 *
 * frees intermediate buffer for decompression
 */
void usbvision_decompress_free(struct usb_usbvision *usbvision)
{
        vfree(usbvision->intra_frame_buffer);
        usbvision->intra_frame_buffer = NULL;

}

/************************************************************
 * Here comes the data parsing stuff that is run as interrupt
 ************************************************************/
/*
 * usbvision_find_header()
 *
 * Locate one of supported header markers in the scratch buffer.
 */
static enum parse_state usbvision_find_header(struct usb_usbvision *usbvision)
{
        struct usbvision_frame *frame;
        int found_header = 0;

        frame = usbvision->cur_frame;

        while (scratch_get_header(usbvision, &frame->isoc_header) == USBVISION_HEADER_LENGTH) {
                /* found header in scratch */
                PDEBUG(DBG_HEADER, "found header: 0x%02x%02x %d %d %d %d %#x 0x%02x %u %u",
                                frame->isoc_header.magic_2,
                                frame->isoc_header.magic_1,
                                frame->isoc_header.header_length,
                                frame->isoc_header.frame_num,
                                frame->isoc_header.frame_phase,
                                frame->isoc_header.frame_latency,
                                frame->isoc_header.data_format,
                                frame->isoc_header.format_param,
                                frame->isoc_header.frame_width,
                                frame->isoc_header.frame_height);

                if (usbvision->request_intra) {
                        if (frame->isoc_header.format_param & 0x80) {
                                found_header = 1;
                                usbvision->last_isoc_frame_num = -1; /* do not check for lost frames this time */
                                usbvision_unrequest_intra(usbvision);
                                break;
                        }
                } else {
                        found_header = 1;
                        break;
                }
        }

        if (found_header) {
                frame->frmwidth = frame->isoc_header.frame_width * usbvision->stretch_width;
                frame->frmheight = frame->isoc_header.frame_height * usbvision->stretch_height;
                frame->v4l2_linesize = (frame->frmwidth * frame->v4l2_format.depth) >> 3;
        } else { /* no header found */
                PDEBUG(DBG_HEADER, "skipping scratch data, no header");
                scratch_reset(usbvision);
                return parse_state_end_parse;
        }

        /* found header */
        if (frame->isoc_header.data_format == ISOC_MODE_COMPRESS) {
                /* check isoc_header.frame_num for lost frames */
                if (usbvision->last_isoc_frame_num >= 0) {
                        if (((usbvision->last_isoc_frame_num + 1) % 32) != frame->isoc_header.frame_num) {
                                /* unexpected frame drop: need to request new intra frame */
                                PDEBUG(DBG_HEADER, "Lost frame before %d on USB", frame->isoc_header.frame_num);
                                usbvision_request_intra(usbvision);
                                return parse_state_next_frame;
                        }
                }
                usbvision->last_isoc_frame_num = frame->isoc_header.frame_num;
        }
        usbvision->header_count++;
        frame->scanstate = scan_state_lines;
        frame->curline = 0;

        return parse_state_continue;
}

static enum parse_state usbvision_parse_lines_422(struct usb_usbvision *usbvision,
                                           long *pcopylen)
{
        volatile struct usbvision_frame *frame;
        unsigned char *f;
        int len;
        int i;
        unsigned char yuyv[4] = { 180, 128, 10, 128 }; /* YUV components */
        unsigned char rv, gv, bv;       /* RGB components */
        int clipmask_index, bytes_per_pixel;
        int stretch_bytes, clipmask_add;

        frame  = usbvision->cur_frame;
        f = frame->data + (frame->v4l2_linesize * frame->curline);

        /* Make sure there's enough data for the entire line */
        len = (frame->isoc_header.frame_width * 2) + 5;
        if (scratch_len(usbvision) < len) {
                PDEBUG(DBG_PARSE, "out of data in line %d, need %u.\n", frame->curline, len);
                return parse_state_out;
        }

        if ((frame->curline + 1) >= frame->frmheight)
                return parse_state_next_frame;

        bytes_per_pixel = frame->v4l2_format.bytes_per_pixel;
        stretch_bytes = (usbvision->stretch_width - 1) * bytes_per_pixel;
        clipmask_index = frame->curline * MAX_FRAME_WIDTH;
        clipmask_add = usbvision->stretch_width;

        for (i = 0; i < frame->frmwidth; i += (2 * usbvision->stretch_width)) {
                scratch_get(usbvision, &yuyv[0], 4);

                if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                        *f++ = yuyv[0]; /* Y */
                        *f++ = yuyv[3]; /* U */
                } else {
                        YUV_TO_RGB_BY_THE_BOOK(yuyv[0], yuyv[1], yuyv[3], rv, gv, bv);
                        switch (frame->v4l2_format.format) {
                        case V4L2_PIX_FMT_RGB565:
                                *f++ = (0x1F & rv) |
                                        (0xE0 & (gv << 5));
                                *f++ = (0x07 & (gv >> 3)) |
                                        (0xF8 &  bv);
                                break;
                        case V4L2_PIX_FMT_RGB24:
                                *f++ = rv;
                                *f++ = gv;
                                *f++ = bv;
                                break;
                        case V4L2_PIX_FMT_RGB32:
                                *f++ = rv;
                                *f++ = gv;
                                *f++ = bv;
                                f++;
                                break;
                        case V4L2_PIX_FMT_RGB555:
                                *f++ = (0x1F & rv) |
                                        (0xE0 & (gv << 5));
                                *f++ = (0x03 & (gv >> 3)) |
                                        (0x7C & (bv << 2));
                                break;
                        }
                }
                clipmask_index += clipmask_add;
                f += stretch_bytes;

                if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                        *f++ = yuyv[2]; /* Y */
                        *f++ = yuyv[1]; /* V */
                } else {
                        YUV_TO_RGB_BY_THE_BOOK(yuyv[2], yuyv[1], yuyv[3], rv, gv, bv);
                        switch (frame->v4l2_format.format) {
                        case V4L2_PIX_FMT_RGB565:
                                *f++ = (0x1F & rv) |
                                        (0xE0 & (gv << 5));
                                *f++ = (0x07 & (gv >> 3)) |
                                        (0xF8 &  bv);
                                break;
                        case V4L2_PIX_FMT_RGB24:
                                *f++ = rv;
                                *f++ = gv;
                                *f++ = bv;
                                break;
                        case V4L2_PIX_FMT_RGB32:
                                *f++ = rv;
                                *f++ = gv;
                                *f++ = bv;
                                f++;
                                break;
                        case V4L2_PIX_FMT_RGB555:
                                *f++ = (0x1F & rv) |
                                        (0xE0 & (gv << 5));
                                *f++ = (0x03 & (gv >> 3)) |
                                        (0x7C & (bv << 2));
                                break;
                        }
                }
                clipmask_index += clipmask_add;
                f += stretch_bytes;
        }

        frame->curline += usbvision->stretch_height;
        *pcopylen += frame->v4l2_linesize * usbvision->stretch_height;

        if (frame->curline >= frame->frmheight)
                return parse_state_next_frame;
        return parse_state_continue;
}

/* The decompression routine  */
static int usbvision_decompress(struct usb_usbvision *usbvision, unsigned char *compressed,
                                                                unsigned char *decompressed, int *start_pos,
                                                                int *block_typestart_pos, int len)
{
        int rest_pixel, idx, pos, extra_pos, block_len, block_type_pos, block_type_len;
        unsigned char block_byte, block_code, block_type, block_type_byte, integrator;

        integrator = 0;
        pos = *start_pos;
        block_type_pos = *block_typestart_pos;
        extra_pos = pos;
        block_len = 0;
        block_byte = 0;
        block_code = 0;
        block_type = 0;
        block_type_byte = 0;
        block_type_len = 0;
        rest_pixel = len;

        for (idx = 0; idx < len; idx++) {
                if (block_len == 0) {
                        if (block_type_len == 0) {
                                block_type_byte = compressed[block_type_pos];
                                block_type_pos++;
                                block_type_len = 4;
                        }
                        block_type = (block_type_byte & 0xC0) >> 6;

                        /* statistic: */
                        usbvision->compr_block_types[block_type]++;

                        pos = extra_pos;
                        if (block_type == 0) {
                                if (rest_pixel >= 24) {
                                        idx += 23;
                                        rest_pixel -= 24;
                                        integrator = decompressed[idx];
                                } else {
                                        idx += rest_pixel - 1;
                                        rest_pixel = 0;
                                }
                        } else {
                                block_code = compressed[pos];
                                pos++;
                                if (rest_pixel >= 24)
                                        block_len  = 24;
                                else
                                        block_len = rest_pixel;
                                rest_pixel -= block_len;
                                extra_pos = pos + (block_len / 4);
                        }
                        block_type_byte <<= 2;
                        block_type_len -= 1;
                }
                if (block_len > 0) {
                        if ((block_len % 4) == 0) {
                                block_byte = compressed[pos];
                                pos++;
                        }
                        if (block_type == 1) /* inter Block */
                                integrator = decompressed[idx];
                        switch (block_byte & 0xC0) {
                        case 0x03 << 6:
                                integrator += compressed[extra_pos];
                                extra_pos++;
                                break;
                        case 0x02 << 6:
                                integrator += block_code;
                                break;
                        case 0x00:
                                integrator -= block_code;
                                break;
                        }
                        decompressed[idx] = integrator;
                        block_byte <<= 2;
                        block_len -= 1;
                }
        }
        *start_pos = extra_pos;
        *block_typestart_pos = block_type_pos;
        return idx;
}


/*
 * usbvision_parse_compress()
 *
 * Parse compressed frame from the scratch buffer, put
 * decoded RGB value into the current frame buffer and add the written
 * number of bytes (RGB) to the *pcopylen.
 *
 */
static enum parse_state usbvision_parse_compress(struct usb_usbvision *usbvision,
                                           long *pcopylen)
{
#define USBVISION_STRIP_MAGIC           0x5A
#define USBVISION_STRIP_LEN_MAX         400
#define USBVISION_STRIP_HEADER_LEN      3

        struct usbvision_frame *frame;
        unsigned char *f, *u = NULL, *v = NULL;
        unsigned char strip_data[USBVISION_STRIP_LEN_MAX];
        unsigned char strip_header[USBVISION_STRIP_HEADER_LEN];
        int idx, idx_end, strip_len, strip_ptr, startblock_pos, block_pos, block_type_pos;
        int clipmask_index;
        int image_size;
        unsigned char rv, gv, bv;
        static unsigned char *Y, *U, *V;

        frame = usbvision->cur_frame;
        image_size = frame->frmwidth * frame->frmheight;
        if ((frame->v4l2_format.format == V4L2_PIX_FMT_YUV422P) ||
            (frame->v4l2_format.format == V4L2_PIX_FMT_YVU420)) {       /* this is a planar format */
                /* ... v4l2_linesize not used here. */
                f = frame->data + (frame->width * frame->curline);
        } else
                f = frame->data + (frame->v4l2_linesize * frame->curline);

        if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) { /* initialise u and v pointers */
                /* get base of u and b planes add halfoffset */
                u = frame->data
                        + image_size
                        + (frame->frmwidth >> 1) * frame->curline;
                v = u + (image_size >> 1);
        } else if (frame->v4l2_format.format == V4L2_PIX_FMT_YVU420) {
                v = frame->data + image_size + ((frame->curline * (frame->width)) >> 2);
                u = v + (image_size >> 2);
        }

        if (frame->curline == 0)
                usbvision_adjust_compression(usbvision);

        if (scratch_len(usbvision) < USBVISION_STRIP_HEADER_LEN)
                return parse_state_out;

        /* get strip header without changing the scratch_read_ptr */
        scratch_set_extra_ptr(usbvision, &strip_ptr, 0);
        scratch_get_extra(usbvision, &strip_header[0], &strip_ptr,
                                USBVISION_STRIP_HEADER_LEN);

        if (strip_header[0] != USBVISION_STRIP_MAGIC) {
                /* wrong strip magic */
                usbvision->strip_magic_errors++;
                return parse_state_next_frame;
        }

        if (frame->curline != (int)strip_header[2]) {
                /* line number mismatch error */
                usbvision->strip_line_number_errors++;
        }

        strip_len = 2 * (unsigned int)strip_header[1];
        if (strip_len > USBVISION_STRIP_LEN_MAX) {
                /* strip overrun */
                /* I think this never happens */
                usbvision_request_intra(usbvision);
        }

        if (scratch_len(usbvision) < strip_len) {
                /* there is not enough data for the strip */
                return parse_state_out;
        }

        if (usbvision->intra_frame_buffer) {
                Y = usbvision->intra_frame_buffer + frame->frmwidth * frame->curline;
                U = usbvision->intra_frame_buffer + image_size + (frame->frmwidth / 2) * (frame->curline / 2);
                V = usbvision->intra_frame_buffer + image_size / 4 * 5 + (frame->frmwidth / 2) * (frame->curline / 2);
        } else {
                return parse_state_next_frame;
        }

        clipmask_index = frame->curline * MAX_FRAME_WIDTH;

        scratch_get(usbvision, strip_data, strip_len);

        idx_end = frame->frmwidth;
        block_type_pos = USBVISION_STRIP_HEADER_LEN;
        startblock_pos = block_type_pos + (idx_end - 1) / 96 + (idx_end / 2 - 1) / 96 + 2;
        block_pos = startblock_pos;

        usbvision->block_pos = block_pos;

        usbvision_decompress(usbvision, strip_data, Y, &block_pos, &block_type_pos, idx_end);
        if (strip_len > usbvision->max_strip_len)
                usbvision->max_strip_len = strip_len;

        if (frame->curline % 2)
                usbvision_decompress(usbvision, strip_data, V, &block_pos, &block_type_pos, idx_end / 2);
        else
                usbvision_decompress(usbvision, strip_data, U, &block_pos, &block_type_pos, idx_end / 2);

        if (block_pos > usbvision->comprblock_pos)
                usbvision->comprblock_pos = block_pos;
        if (block_pos > strip_len)
                usbvision->strip_len_errors++;

        for (idx = 0; idx < idx_end; idx++) {
                if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                        *f++ = Y[idx];
                        *f++ = idx & 0x01 ? U[idx / 2] : V[idx / 2];
                } else if (frame->v4l2_format.format == V4L2_PIX_FMT_YUV422P) {
                        *f++ = Y[idx];
                        if (idx & 0x01)
                                *u++ = U[idx >> 1];
                        else
                                *v++ = V[idx >> 1];
                } else if (frame->v4l2_format.format == V4L2_PIX_FMT_YVU420) {
                        *f++ = Y[idx];
                        if (!((idx & 0x01) | (frame->curline & 0x01))) {
                                /* only need do this for 1 in 4 pixels */
                                /* intraframe buffer is YUV420 format */
                                *u++ = U[idx >> 1];
                                *v++ = V[idx >> 1];
                        }
                } else {
                        YUV_TO_RGB_BY_THE_BOOK(Y[idx], U[idx / 2], V[idx / 2], rv, gv, bv);
                        switch (frame->v4l2_format.format) {
                        case V4L2_PIX_FMT_GREY:
                                *f++ = Y[idx];
                                break;
                        case V4L2_PIX_FMT_RGB555:
                                *f++ = (0x1F & rv) |
                                        (0xE0 & (gv << 5));
                                *f++ = (0x03 & (gv >> 3)) |
                                        (0x7C & (bv << 2));
                                break;
                        case V4L2_PIX_FMT_RGB565:
                                *f++ = (0x1F & rv) |
                                        (0xE0 & (gv << 5));
                                *f++ = (0x07 & (gv >> 3)) |
                                        (0xF8 & bv);
                                break;
                        case V4L2_PIX_FMT_RGB24:
                                *f++ = rv;
                                *f++ = gv;
                                *f++ = bv;
                                break;
                        case V4L2_PIX_FMT_RGB32:
                                *f++ = rv;
                                *f++ = gv;
                                *f++ = bv;
                                f++;
                                break;
                        }
                }
                clipmask_index++;
        }
        /* Deal with non-integer no. of bytes for YUV420P */
        if (frame->v4l2_format.format != V4L2_PIX_FMT_YVU420)
                *pcopylen += frame->v4l2_linesize;
        else
                *pcopylen += frame->curline & 0x01 ? frame->v4l2_linesize : frame->v4l2_linesize << 1;

        frame->curline += 1;

        if (frame->curline >= frame->frmheight)
                return parse_state_next_frame;
        return parse_state_continue;

}


/*
 * usbvision_parse_lines_420()
 *
 * Parse two lines from the scratch buffer, put
 * decoded RGB value into the current frame buffer and add the written
 * number of bytes (RGB) to the *pcopylen.
 *
 */
static enum parse_state usbvision_parse_lines_420(struct usb_usbvision *usbvision,
                                           long *pcopylen)
{
        struct usbvision_frame *frame;
        unsigned char *f_even = NULL, *f_odd = NULL;
        unsigned int pixel_per_line, block;
        int pixel, block_split;
        int y_ptr, u_ptr, v_ptr, y_odd_offset;
        const int y_block_size = 128;
        const int uv_block_size = 64;
        const int sub_block_size = 32;
        const int y_step[] = { 0, 0, 0, 2 }, y_step_size = 4;
        const int uv_step[] = { 0, 0, 0, 4 }, uv_step_size = 4;
        unsigned char y[2], u, v;       /* YUV components */
        int y_, u_, v_, vb, uvg, ur;
        int r_, g_, b_;                 /* RGB components */
        unsigned char g;
        int clipmask_even_index, clipmask_odd_index, bytes_per_pixel;
        int clipmask_add, stretch_bytes;

        frame  = usbvision->cur_frame;
        f_even = frame->data + (frame->v4l2_linesize * frame->curline);
        f_odd  = f_even + frame->v4l2_linesize * usbvision->stretch_height;

        /* Make sure there's enough data for the entire line */
        /* In this mode usbvision transfer 3 bytes for every 2 pixels */
        /* I need two lines to decode the color */
        bytes_per_pixel = frame->v4l2_format.bytes_per_pixel;
        stretch_bytes = (usbvision->stretch_width - 1) * bytes_per_pixel;
        clipmask_even_index = frame->curline * MAX_FRAME_WIDTH;
        clipmask_odd_index  = clipmask_even_index + MAX_FRAME_WIDTH;
        clipmask_add = usbvision->stretch_width;
        pixel_per_line = frame->isoc_header.frame_width;

        if (scratch_len(usbvision) < (int)pixel_per_line * 3) {
                /* printk(KERN_DEBUG "out of data, need %d\n", len); */
                return parse_state_out;
        }

        if ((frame->curline + 1) >= frame->frmheight)
                return parse_state_next_frame;

        block_split = (pixel_per_line%y_block_size) ? 1 : 0;    /* are some blocks splitted into different lines? */

        y_odd_offset = (pixel_per_line / y_block_size) * (y_block_size + uv_block_size)
                        + block_split * uv_block_size;

        scratch_set_extra_ptr(usbvision, &y_ptr, y_odd_offset);
        scratch_set_extra_ptr(usbvision, &u_ptr, y_block_size);
        scratch_set_extra_ptr(usbvision, &v_ptr, y_odd_offset
                        + (4 - block_split) * sub_block_size);

        for (block = 0; block < (pixel_per_line / sub_block_size); block++) {
                for (pixel = 0; pixel < sub_block_size; pixel += 2) {
                        scratch_get(usbvision, &y[0], 2);
                        scratch_get_extra(usbvision, &u, &u_ptr, 1);
                        scratch_get_extra(usbvision, &v, &v_ptr, 1);

                        /* I don't use the YUV_TO_RGB macro for better performance */
                        v_ = v - 128;
                        u_ = u - 128;
                        vb = 132252 * v_;
                        uvg = -53281 * u_ - 25625 * v_;
                        ur = 104595 * u_;

                        if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                                *f_even++ = y[0];
                                *f_even++ = v;
                        } else {
                                y_ = 76284 * (y[0] - 16);

                                b_ = (y_ + vb) >> 16;
                                g_ = (y_ + uvg) >> 16;
                                r_ = (y_ + ur) >> 16;

                                switch (frame->v4l2_format.format) {
                                case V4L2_PIX_FMT_RGB565:
                                        g = LIMIT_RGB(g_);
                                        *f_even++ =
                                                (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_even++ =
                                                (0x07 & (g >> 3)) |
                                                (0xF8 &  LIMIT_RGB(b_));
                                        break;
                                case V4L2_PIX_FMT_RGB24:
                                        *f_even++ = LIMIT_RGB(r_);
                                        *f_even++ = LIMIT_RGB(g_);
                                        *f_even++ = LIMIT_RGB(b_);
                                        break;
                                case V4L2_PIX_FMT_RGB32:
                                        *f_even++ = LIMIT_RGB(r_);
                                        *f_even++ = LIMIT_RGB(g_);
                                        *f_even++ = LIMIT_RGB(b_);
                                        f_even++;
                                        break;
                                case V4L2_PIX_FMT_RGB555:
                                        g = LIMIT_RGB(g_);
                                        *f_even++ = (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_even++ = (0x03 & (g >> 3)) |
                                                (0x7C & (LIMIT_RGB(b_) << 2));
                                        break;
                                }
                        }
                        clipmask_even_index += clipmask_add;
                        f_even += stretch_bytes;

                        if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                                *f_even++ = y[1];
                                *f_even++ = u;
                        } else {
                                y_ = 76284 * (y[1] - 16);

                                b_ = (y_ + vb) >> 16;
                                g_ = (y_ + uvg) >> 16;
                                r_ = (y_ + ur) >> 16;

                                switch (frame->v4l2_format.format) {
                                case V4L2_PIX_FMT_RGB565:
                                        g = LIMIT_RGB(g_);
                                        *f_even++ =
                                                (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_even++ =
                                                (0x07 & (g >> 3)) |
                                                (0xF8 &  LIMIT_RGB(b_));
                                        break;
                                case V4L2_PIX_FMT_RGB24:
                                        *f_even++ = LIMIT_RGB(r_);
                                        *f_even++ = LIMIT_RGB(g_);
                                        *f_even++ = LIMIT_RGB(b_);
                                        break;
                                case V4L2_PIX_FMT_RGB32:
                                        *f_even++ = LIMIT_RGB(r_);
                                        *f_even++ = LIMIT_RGB(g_);

                                        *f_even++ = LIMIT_RGB(b_);
                                        f_even++;
                                        break;
                                case V4L2_PIX_FMT_RGB555:
                                        g = LIMIT_RGB(g_);
                                        *f_even++ = (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_even++ = (0x03 & (g >> 3)) |
                                                (0x7C & (LIMIT_RGB(b_) << 2));
                                        break;
                                }
                        }
                        clipmask_even_index += clipmask_add;
                        f_even += stretch_bytes;

                        scratch_get_extra(usbvision, &y[0], &y_ptr, 2);

                        if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                                *f_odd++ = y[0];
                                *f_odd++ = v;
                        } else {
                                y_ = 76284 * (y[0] - 16);

                                b_ = (y_ + vb) >> 16;
                                g_ = (y_ + uvg) >> 16;
                                r_ = (y_ + ur) >> 16;

                                switch (frame->v4l2_format.format) {
                                case V4L2_PIX_FMT_RGB565:
                                        g = LIMIT_RGB(g_);
                                        *f_odd++ =
                                                (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_odd++ =
                                                (0x07 & (g >> 3)) |
                                                (0xF8 &  LIMIT_RGB(b_));
                                        break;
                                case V4L2_PIX_FMT_RGB24:
                                        *f_odd++ = LIMIT_RGB(r_);
                                        *f_odd++ = LIMIT_RGB(g_);
                                        *f_odd++ = LIMIT_RGB(b_);
                                        break;
                                case V4L2_PIX_FMT_RGB32:
                                        *f_odd++ = LIMIT_RGB(r_);
                                        *f_odd++ = LIMIT_RGB(g_);
                                        *f_odd++ = LIMIT_RGB(b_);
                                        f_odd++;
                                        break;
                                case V4L2_PIX_FMT_RGB555:
                                        g = LIMIT_RGB(g_);
                                        *f_odd++ = (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_odd++ = (0x03 & (g >> 3)) |
                                                (0x7C & (LIMIT_RGB(b_) << 2));
                                        break;
                                }
                        }
                        clipmask_odd_index += clipmask_add;
                        f_odd += stretch_bytes;

                        if (frame->v4l2_format.format == V4L2_PIX_FMT_YUYV) {
                                *f_odd++ = y[1];
                                *f_odd++ = u;
                        } else {
                                y_ = 76284 * (y[1] - 16);

                                b_ = (y_ + vb) >> 16;
                                g_ = (y_ + uvg) >> 16;
                                r_ = (y_ + ur) >> 16;

                                switch (frame->v4l2_format.format) {
                                case V4L2_PIX_FMT_RGB565:
                                        g = LIMIT_RGB(g_);
                                        *f_odd++ =
                                                (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_odd++ =
                                                (0x07 & (g >> 3)) |
                                                (0xF8 &  LIMIT_RGB(b_));
                                        break;
                                case V4L2_PIX_FMT_RGB24:
                                        *f_odd++ = LIMIT_RGB(r_);
                                        *f_odd++ = LIMIT_RGB(g_);
                                        *f_odd++ = LIMIT_RGB(b_);
                                        break;
                                case V4L2_PIX_FMT_RGB32:
                                        *f_odd++ = LIMIT_RGB(r_);
                                        *f_odd++ = LIMIT_RGB(g_);
                                        *f_odd++ = LIMIT_RGB(b_);
                                        f_odd++;
                                        break;
                                case V4L2_PIX_FMT_RGB555:
                                        g = LIMIT_RGB(g_);
                                        *f_odd++ = (0x1F & LIMIT_RGB(r_)) |
                                                (0xE0 & (g << 5));
                                        *f_odd++ = (0x03 & (g >> 3)) |
                                                (0x7C & (LIMIT_RGB(b_) << 2));
                                        break;
                                }
                        }
                        clipmask_odd_index += clipmask_add;
                        f_odd += stretch_bytes;
                }

                scratch_rm_old(usbvision, y_step[block % y_step_size] * sub_block_size);
                scratch_inc_extra_ptr(&y_ptr, y_step[(block + 2 * block_split) % y_step_size]
                                * sub_block_size);
                scratch_inc_extra_ptr(&u_ptr, uv_step[block % uv_step_size]
                                * sub_block_size);
                scratch_inc_extra_ptr(&v_ptr, uv_step[(block + 2 * block_split) % uv_step_size]
                                * sub_block_size);
        }

        scratch_rm_old(usbvision, pixel_per_line * 3 / 2
                        + block_split * sub_block_size);

        frame->curline += 2 * usbvision->stretch_height;
        *pcopylen += frame->v4l2_linesize * 2 * usbvision->stretch_height;

        if (frame->curline >= frame->frmheight)
                return parse_state_next_frame;
        return parse_state_continue;
}

/*
 * usbvision_parse_data()
 *
 * Generic routine to parse the scratch buffer. It employs either
 * usbvision_find_header() or usbvision_parse_lines() to do most
 * of work.
 *
 */
static void usbvision_parse_data(struct usb_usbvision *usbvision)
{
        struct usbvision_frame *frame;
        enum parse_state newstate;
        long copylen = 0;
        unsigned long lock_flags;

        frame = usbvision->cur_frame;

        PDEBUG(DBG_PARSE, "parsing len=%d\n", scratch_len(usbvision));

        while (1) {
                newstate = parse_state_out;
                if (scratch_len(usbvision)) {
                        if (frame->scanstate == scan_state_scanning) {
                                newstate = usbvision_find_header(usbvision);
                        } else if (frame->scanstate == scan_state_lines) {
                                if (usbvision->isoc_mode == ISOC_MODE_YUV420)
                                        newstate = usbvision_parse_lines_420(usbvision, &copylen);
                                else if (usbvision->isoc_mode == ISOC_MODE_YUV422)
                                        newstate = usbvision_parse_lines_422(usbvision, &copylen);
                                else if (usbvision->isoc_mode == ISOC_MODE_COMPRESS)
                                        newstate = usbvision_parse_compress(usbvision, &copylen);
                        }
                }
                if (newstate == parse_state_continue)
                        continue;
                if ((newstate == parse_state_next_frame) || (newstate == parse_state_out))
                        break;
                return; /* parse_state_end_parse */
        }

        if (newstate == parse_state_next_frame) {
                frame->grabstate = frame_state_done;
                v4l2_get_timestamp(&(frame->timestamp));
                frame->sequence = usbvision->frame_num;

                spin_lock_irqsave(&usbvision->queue_lock, lock_flags);
                list_move_tail(&(frame->frame), &usbvision->outqueue);
                usbvision->cur_frame = NULL;
                spin_unlock_irqrestore(&usbvision->queue_lock, lock_flags);

                usbvision->frame_num++;

                /* This will cause the process to request another frame. */
                if (waitqueue_active(&usbvision->wait_frame)) {
                        PDEBUG(DBG_PARSE, "Wake up !");
                        wake_up_interruptible(&usbvision->wait_frame);
                }
        } else {
                frame->grabstate = frame_state_grabbing;
        }

        /* Update the frame's uncompressed length. */
        frame->scanlength += copylen;
}


/*
 * Make all of the blocks of data contiguous
 */
static int usbvision_compress_isochronous(struct usb_usbvision *usbvision,
                                          struct urb *urb)
{
        unsigned char *packet_data;
        int i, totlen = 0;

        for (i = 0; i < urb->number_of_packets; i++) {
                int packet_len = urb->iso_frame_desc[i].actual_length;
                int packet_stat = urb->iso_frame_desc[i].status;

                packet_data = urb->transfer_buffer + urb->iso_frame_desc[i].offset;

                /* Detect and ignore errored packets */
                if (packet_stat) {      /* packet_stat != 0 ????????????? */
                        PDEBUG(DBG_ISOC, "data error: [%d] len=%d, status=%X", i, packet_len, packet_stat);
                        usbvision->isoc_err_count++;
                        continue;
                }

                /* Detect and ignore empty packets */
                if (packet_len < 0) {
                        PDEBUG(DBG_ISOC, "error packet [%d]", i);
                        usbvision->isoc_skip_count++;
                        continue;
                } else if (packet_len == 0) {   /* Frame end ????? */
                        PDEBUG(DBG_ISOC, "null packet [%d]", i);
                        usbvision->isocstate = isoc_state_no_frame;
                        usbvision->isoc_skip_count++;
                        continue;
                } else if (packet_len > usbvision->isoc_packet_size) {
                        PDEBUG(DBG_ISOC, "packet[%d] > isoc_packet_size", i);
                        usbvision->isoc_skip_count++;
                        continue;
                }

                PDEBUG(DBG_ISOC, "packet ok [%d] len=%d", i, packet_len);

                if (usbvision->isocstate == isoc_state_no_frame) { /* new frame begins */
                        usbvision->isocstate = isoc_state_in_frame;
                        scratch_mark_header(usbvision);
                        usbvision_measure_bandwidth(usbvision);
                        PDEBUG(DBG_ISOC, "packet with header");
                }

                /*
                 * If usbvision continues to feed us with data but there is no
                 * consumption (if, for example, V4L client fell asleep) we
                 * may overflow the buffer. We have to move old data over to
                 * free room for new data. This is bad for old data. If we
                 * just drop new data then it's bad for new data... choose
                 * your favorite evil here.
                 */
                if (scratch_free(usbvision) < packet_len) {
                        usbvision->scratch_ovf_count++;
                        PDEBUG(DBG_ISOC, "scratch buf overflow! scr_len: %d, n: %d",
                               scratch_len(usbvision), packet_len);
                        scratch_rm_old(usbvision, packet_len - scratch_free(usbvision));
                }

                /* Now we know that there is enough room in scratch buffer */
                scratch_put(usbvision, packet_data, packet_len);
                totlen += packet_len;
                usbvision->isoc_data_count += packet_len;
                usbvision->isoc_packet_count++;
        }
#if ENABLE_HEXDUMP
        if (totlen > 0) {
                static int foo;

                if (foo < 1) {
                        printk(KERN_DEBUG "+%d.\n", usbvision->scratchlen);
                        usbvision_hexdump(data0, (totlen > 64) ? 64 : totlen);
                        ++foo;
                }
        }
#endif
        return totlen;
}

static void usbvision_isoc_irq(struct urb *urb)
{
        int err_code = 0;
        int len;
        struct usb_usbvision *usbvision = urb->context;
        int i;
        unsigned long start_time = jiffies;
        struct usbvision_frame **f;

        /* We don't want to do anything if we are about to be removed! */
        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return;

        /* any urb with wrong status is ignored without acknowledgement */
        if (urb->status == -ENOENT)
                return;

        f = &usbvision->cur_frame;

        /* Manage streaming interruption */
        if (usbvision->streaming == stream_interrupt) {
                usbvision->streaming = stream_idle;
                if ((*f)) {
                        (*f)->grabstate = frame_state_ready;
                        (*f)->scanstate = scan_state_scanning;
                }
                PDEBUG(DBG_IRQ, "stream interrupted");
                wake_up_interruptible(&usbvision->wait_stream);
        }

        /* Copy the data received into our scratch buffer */
        len = usbvision_compress_isochronous(usbvision, urb);

        usbvision->isoc_urb_count++;
        usbvision->urb_length = len;

        if (usbvision->streaming == stream_on) {
                /* If we collected enough data let's parse! */
                if (scratch_len(usbvision) > USBVISION_HEADER_LENGTH &&
                    !list_empty(&(usbvision->inqueue))) {
                        if (!(*f)) {
                                (*f) = list_entry(usbvision->inqueue.next,
                                                  struct usbvision_frame,
                                                  frame);
                        }
                        usbvision_parse_data(usbvision);
                } else {
                        /* If we don't have a frame
                          we're current working on, complain */
                        PDEBUG(DBG_IRQ,
                               "received data, but no one needs it");
                        scratch_reset(usbvision);
                }
        } else {
                PDEBUG(DBG_IRQ, "received data, but no one needs it");
                scratch_reset(usbvision);
        }

        usbvision->time_in_irq += jiffies - start_time;

        for (i = 0; i < USBVISION_URB_FRAMES; i++) {
                urb->iso_frame_desc[i].status = 0;
                urb->iso_frame_desc[i].actual_length = 0;
        }

        urb->status = 0;
        urb->dev = usbvision->dev;
        err_code = usb_submit_urb(urb, GFP_ATOMIC);

        if (err_code) {
                dev_err(&usbvision->dev->dev,
                        "%s: usb_submit_urb failed: error %d\n",
                                __func__, err_code);
        }

        return;
}

/*************************************/
/* Low level usbvision access functions */
/*************************************/

/*
 * usbvision_read_reg()
 *
 * return  < 0 -> Error
 *        >= 0 -> Data
 */

int usbvision_read_reg(struct usb_usbvision *usbvision, unsigned char reg)
{
        int err_code = 0;
        unsigned char *buffer = usbvision->ctrl_urb_buffer;

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return -1;

        err_code = usb_control_msg(usbvision->dev, usb_rcvctrlpipe(usbvision->dev, 1),
                                USBVISION_OP_CODE,
                                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT,
                                0, (__u16) reg, buffer, 1, HZ);

        if (err_code < 0) {
                dev_err(&usbvision->dev->dev,
                        "%s: failed: error %d\n", __func__, err_code);
                return err_code;
        }
        return buffer[0];
}

/*
 * usbvision_write_reg()
 *
 * return 1 -> Reg written
 *        0 -> usbvision is not yet ready
 *       -1 -> Something went wrong
 */

int usbvision_write_reg(struct usb_usbvision *usbvision, unsigned char reg,
                            unsigned char value)
{
        int err_code = 0;

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        usbvision->ctrl_urb_buffer[0] = value;
        err_code = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                                USBVISION_OP_CODE,
                                USB_DIR_OUT | USB_TYPE_VENDOR |
                                USB_RECIP_ENDPOINT, 0, (__u16) reg,
                                usbvision->ctrl_urb_buffer, 1, HZ);

        if (err_code < 0) {
                dev_err(&usbvision->dev->dev,
                        "%s: failed: error %d\n", __func__, err_code);
        }
        return err_code;
}


static void usbvision_ctrl_urb_complete(struct urb *urb)
{
        struct usb_usbvision *usbvision = (struct usb_usbvision *)urb->context;

        PDEBUG(DBG_IRQ, "");
        usbvision->ctrl_urb_busy = 0;
        if (waitqueue_active(&usbvision->ctrl_urb_wq))
                wake_up_interruptible(&usbvision->ctrl_urb_wq);
}


static int usbvision_write_reg_irq(struct usb_usbvision *usbvision, int address,
                                unsigned char *data, int len)
{
        int err_code = 0;

        PDEBUG(DBG_IRQ, "");
        if (len > 8)
                return -EFAULT;
        if (usbvision->ctrl_urb_busy)
                return -EBUSY;
        usbvision->ctrl_urb_busy = 1;

        usbvision->ctrl_urb_setup.bRequestType = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT;
        usbvision->ctrl_urb_setup.bRequest     = USBVISION_OP_CODE;
        usbvision->ctrl_urb_setup.wValue       = 0;
        usbvision->ctrl_urb_setup.wIndex       = cpu_to_le16(address);
        usbvision->ctrl_urb_setup.wLength      = cpu_to_le16(len);
        usb_fill_control_urb(usbvision->ctrl_urb, usbvision->dev,
                                                        usb_sndctrlpipe(usbvision->dev, 1),
                                                        (unsigned char *)&usbvision->ctrl_urb_setup,
                                                        (void *)usbvision->ctrl_urb_buffer, len,
                                                        usbvision_ctrl_urb_complete,
                                                        (void *)usbvision);

        memcpy(usbvision->ctrl_urb_buffer, data, len);

        err_code = usb_submit_urb(usbvision->ctrl_urb, GFP_ATOMIC);
        if (err_code < 0) {
                /* error in usb_submit_urb() */
                usbvision->ctrl_urb_busy = 0;
        }
        PDEBUG(DBG_IRQ, "submit %d byte: error %d", len, err_code);
        return err_code;
}


static int usbvision_init_compression(struct usb_usbvision *usbvision)
{
        usbvision->last_isoc_frame_num = -1;
        usbvision->isoc_data_count = 0;
        usbvision->isoc_packet_count = 0;
        usbvision->isoc_skip_count = 0;
        usbvision->compr_level = 50;
        usbvision->last_compr_level = -1;
        usbvision->isoc_urb_count = 0;
        usbvision->request_intra = 1;
        usbvision->isoc_measure_bandwidth_count = 0;

        return 0;
}

/* this function measures the used bandwidth since last call
 * return:    0 : no error
 * sets used_bandwidth to 1-100 : 1-100% of full bandwidth resp. to isoc_packet_size
 */
static int usbvision_measure_bandwidth(struct usb_usbvision *usbvision)
{
        if (usbvision->isoc_measure_bandwidth_count < 2) { /* this gives an average bandwidth of 3 frames */
                usbvision->isoc_measure_bandwidth_count++;
                return 0;
        }
        if ((usbvision->isoc_packet_size > 0) && (usbvision->isoc_packet_count > 0)) {
                usbvision->used_bandwidth = usbvision->isoc_data_count /
                                        (usbvision->isoc_packet_count + usbvision->isoc_skip_count) *
                                        100 / usbvision->isoc_packet_size;
        }
        usbvision->isoc_measure_bandwidth_count = 0;
        usbvision->isoc_data_count = 0;
        usbvision->isoc_packet_count = 0;
        usbvision->isoc_skip_count = 0;
        return 0;
}

static int usbvision_adjust_compression(struct usb_usbvision *usbvision)
{
        int err_code = 0;
        unsigned char buffer[6];

        PDEBUG(DBG_IRQ, "");
        if ((adjust_compression) && (usbvision->used_bandwidth > 0)) {
                usbvision->compr_level += (usbvision->used_bandwidth - 90) / 2;
                RESTRICT_TO_RANGE(usbvision->compr_level, 0, 100);
                if (usbvision->compr_level != usbvision->last_compr_level) {
                        int distortion;

                        if (usbvision->bridge_type == BRIDGE_NT1004 || usbvision->bridge_type == BRIDGE_NT1005) {
                                buffer[0] = (unsigned char)(4 + 16 * usbvision->compr_level / 100);     /* PCM Threshold 1 */
                                buffer[1] = (unsigned char)(4 + 8 * usbvision->compr_level / 100);      /* PCM Threshold 2 */
                                distortion = 7 + 248 * usbvision->compr_level / 100;
                                buffer[2] = (unsigned char)(distortion & 0xFF);                         /* Average distortion Threshold (inter) */
                                buffer[3] = (unsigned char)(distortion & 0xFF);                         /* Average distortion Threshold (intra) */
                                distortion = 1 + 42 * usbvision->compr_level / 100;
                                buffer[4] = (unsigned char)(distortion & 0xFF);                         /* Maximum distortion Threshold (inter) */
                                buffer[5] = (unsigned char)(distortion & 0xFF);                         /* Maximum distortion Threshold (intra) */
                        } else { /* BRIDGE_NT1003 */
                                buffer[0] = (unsigned char)(4 + 16 * usbvision->compr_level / 100);     /* PCM threshold 1 */
                                buffer[1] = (unsigned char)(4 + 8 * usbvision->compr_level / 100);      /* PCM threshold 2 */
                                distortion = 2 + 253 * usbvision->compr_level / 100;
                                buffer[2] = (unsigned char)(distortion & 0xFF);                         /* distortion threshold bit0-7 */
                                buffer[3] = 0;  /* (unsigned char)((distortion >> 8) & 0x0F);           distortion threshold bit 8-11 */
                                distortion = 0 + 43 * usbvision->compr_level / 100;
                                buffer[4] = (unsigned char)(distortion & 0xFF);                         /* maximum distortion bit0-7 */
                                buffer[5] = 0; /* (unsigned char)((distortion >> 8) & 0x01);            maximum distortion bit 8 */
                        }
                        err_code = usbvision_write_reg_irq(usbvision, USBVISION_PCM_THR1, buffer, 6);
                        if (err_code == 0) {
                                PDEBUG(DBG_IRQ, "new compr params %#02x %#02x %#02x %#02x %#02x %#02x", buffer[0],
                                                                buffer[1], buffer[2], buffer[3], buffer[4], buffer[5]);
                                usbvision->last_compr_level = usbvision->compr_level;
                        }
                }
        }
        return err_code;
}

static int usbvision_request_intra(struct usb_usbvision *usbvision)
{
        unsigned char buffer[1];

        PDEBUG(DBG_IRQ, "");
        usbvision->request_intra = 1;
        buffer[0] = 1;
        usbvision_write_reg_irq(usbvision, USBVISION_FORCE_INTRA, buffer, 1);
        return 0;
}

static int usbvision_unrequest_intra(struct usb_usbvision *usbvision)
{
        unsigned char buffer[1];

        PDEBUG(DBG_IRQ, "");
        usbvision->request_intra = 0;
        buffer[0] = 0;
        usbvision_write_reg_irq(usbvision, USBVISION_FORCE_INTRA, buffer, 1);
        return 0;
}

/*******************************
 * usbvision utility functions
 *******************************/

int usbvision_power_off(struct usb_usbvision *usbvision)
{
        int err_code = 0;

        PDEBUG(DBG_FUNC, "");

        err_code = usbvision_write_reg(usbvision, USBVISION_PWR_REG, USBVISION_SSPND_EN);
        if (err_code == 1)
                usbvision->power = 0;
        PDEBUG(DBG_FUNC, "%s: err_code %d", (err_code != 1) ? "ERROR" : "power is off", err_code);
        return err_code;
}

/* configure webcam image sensor using the serial port */
static int usbvision_init_webcam(struct usb_usbvision *usbvision)
{
        int rc;
        int i;
        static char init_values[38][3] = {
                { 0x04, 0x12, 0x08 }, { 0x05, 0xff, 0xc8 }, { 0x06, 0x18, 0x07 }, { 0x07, 0x90, 0x00 },
                { 0x09, 0x00, 0x00 }, { 0x0a, 0x00, 0x00 }, { 0x0b, 0x08, 0x00 }, { 0x0d, 0xcc, 0xcc },
                { 0x0e, 0x13, 0x14 }, { 0x10, 0x9b, 0x83 }, { 0x11, 0x5a, 0x3f }, { 0x12, 0xe4, 0x73 },
                { 0x13, 0x88, 0x84 }, { 0x14, 0x89, 0x80 }, { 0x15, 0x00, 0x20 }, { 0x16, 0x00, 0x00 },
                { 0x17, 0xff, 0xa0 }, { 0x18, 0x6b, 0x20 }, { 0x19, 0x22, 0x40 }, { 0x1a, 0x10, 0x07 },
                { 0x1b, 0x00, 0x47 }, { 0x1c, 0x03, 0xe0 }, { 0x1d, 0x00, 0x00 }, { 0x1e, 0x00, 0x00 },
                { 0x1f, 0x00, 0x00 }, { 0x20, 0x00, 0x00 }, { 0x21, 0x00, 0x00 }, { 0x22, 0x00, 0x00 },
                { 0x23, 0x00, 0x00 }, { 0x24, 0x00, 0x00 }, { 0x25, 0x00, 0x00 }, { 0x26, 0x00, 0x00 },
                { 0x27, 0x00, 0x00 }, { 0x28, 0x00, 0x00 }, { 0x29, 0x00, 0x00 }, { 0x08, 0x80, 0x60 },
                { 0x0f, 0x2d, 0x24 }, { 0x0c, 0x80, 0x80 }
        };
        unsigned char *value = usbvision->ctrl_urb_buffer;

        /* the only difference between PAL and NTSC init_values */
        if (usbvision_device_data[usbvision->dev_model].video_norm == V4L2_STD_NTSC)
                init_values[4][1] = 0x34;

        for (i = 0; i < sizeof(init_values) / 3; i++) {
                usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_SER_MODE_SOFT);
                memcpy(value, init_values[i], 3);
                rc = usb_control_msg(usbvision->dev,
                                     usb_sndctrlpipe(usbvision->dev, 1),
                                     USBVISION_OP_CODE,
                                     USB_DIR_OUT | USB_TYPE_VENDOR |
                                     USB_RECIP_ENDPOINT, 0,
                                     (__u16) USBVISION_SER_DAT1, value,
                                     3, HZ);
                if (rc < 0)
                        return rc;
                usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_SER_MODE_SIO);
                /* write 3 bytes to the serial port using SIO mode */
                usbvision_write_reg(usbvision, USBVISION_SER_CONT, 3 | 0x10);
                usbvision_write_reg(usbvision, USBVISION_IOPIN_REG, 0);
                usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_SER_MODE_SOFT);
                usbvision_write_reg(usbvision, USBVISION_IOPIN_REG, USBVISION_IO_2);
                usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_SER_MODE_SOFT | USBVISION_CLK_OUT);
                usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_SER_MODE_SOFT | USBVISION_DAT_IO);
                usbvision_write_reg(usbvision, USBVISION_SER_MODE, USBVISION_SER_MODE_SOFT | USBVISION_CLK_OUT | USBVISION_DAT_IO);
        }

        return 0;
}

/*
 * usbvision_set_video_format()
 *
 */
static int usbvision_set_video_format(struct usb_usbvision *usbvision, int format)
{
        static const char proc[] = "usbvision_set_video_format";
        unsigned char *value = usbvision->ctrl_urb_buffer;
        int rc;

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        PDEBUG(DBG_FUNC, "isoc_mode %#02x", format);

        if ((format != ISOC_MODE_YUV422)
            && (format != ISOC_MODE_YUV420)
            && (format != ISOC_MODE_COMPRESS)) {
                printk(KERN_ERR "usbvision: unknown video format %02x, using default YUV420",
                       format);
                format = ISOC_MODE_YUV420;
        }
        value[0] = 0x0A;  /* TODO: See the effect of the filter */
        value[1] = format; /* Sets the VO_MODE register which follows FILT_CONT */
        rc = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                             USBVISION_OP_CODE,
                             USB_DIR_OUT | USB_TYPE_VENDOR |
                             USB_RECIP_ENDPOINT, 0,
                             (__u16) USBVISION_FILT_CONT, value, 2, HZ);

        if (rc < 0) {
                printk(KERN_ERR "%s: ERROR=%d. USBVISION stopped - "
                       "reconnect or reload driver.\n", proc, rc);
        }
        usbvision->isoc_mode = format;
        return rc;
}

/*
 * usbvision_set_output()
 *
 */

int usbvision_set_output(struct usb_usbvision *usbvision, int width,
                         int height)
{
        int err_code = 0;
        int usb_width, usb_height;
        unsigned int frame_rate = 0, frame_drop = 0;
        unsigned char *value = usbvision->ctrl_urb_buffer;

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        if (width > MAX_USB_WIDTH) {
                usb_width = width / 2;
                usbvision->stretch_width = 2;
        } else {
                usb_width = width;
                usbvision->stretch_width = 1;
        }

        if (height > MAX_USB_HEIGHT) {
                usb_height = height / 2;
                usbvision->stretch_height = 2;
        } else {
                usb_height = height;
                usbvision->stretch_height = 1;
        }

        RESTRICT_TO_RANGE(usb_width, MIN_FRAME_WIDTH, MAX_USB_WIDTH);
        usb_width &= ~(MIN_FRAME_WIDTH-1);
        RESTRICT_TO_RANGE(usb_height, MIN_FRAME_HEIGHT, MAX_USB_HEIGHT);
        usb_height &= ~(1);

        PDEBUG(DBG_FUNC, "usb %dx%d; screen %dx%d; stretch %dx%d",
                                                usb_width, usb_height, width, height,
                                                usbvision->stretch_width, usbvision->stretch_height);

        /* I'll not rewrite the same values */
        if ((usb_width != usbvision->curwidth) || (usb_height != usbvision->curheight)) {
                value[0] = usb_width & 0xff;            /* LSB */
                value[1] = (usb_width >> 8) & 0x03;     /* MSB */
                value[2] = usb_height & 0xff;           /* LSB */
                value[3] = (usb_height >> 8) & 0x03;    /* MSB */

                err_code = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                             USBVISION_OP_CODE,
                             USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT,
                                 0, (__u16) USBVISION_LXSIZE_O, value, 4, HZ);

                if (err_code < 0) {
                        dev_err(&usbvision->dev->dev,
                                "%s failed: error %d\n", __func__, err_code);
                        return err_code;
                }
                usbvision->curwidth = usbvision->stretch_width * usb_width;
                usbvision->curheight = usbvision->stretch_height * usb_height;
        }

        if (usbvision->isoc_mode == ISOC_MODE_YUV422)
                frame_rate = (usbvision->isoc_packet_size * 1000) / (usb_width * usb_height * 2);
        else if (usbvision->isoc_mode == ISOC_MODE_YUV420)
                frame_rate = (usbvision->isoc_packet_size * 1000) / ((usb_width * usb_height * 12) / 8);
        else
                frame_rate = FRAMERATE_MAX;

        if (usbvision->tvnorm_id & V4L2_STD_625_50)
                frame_drop = frame_rate * 32 / 25 - 1;
        else if (usbvision->tvnorm_id & V4L2_STD_525_60)
                frame_drop = frame_rate * 32 / 30 - 1;

        RESTRICT_TO_RANGE(frame_drop, FRAMERATE_MIN, FRAMERATE_MAX);

        PDEBUG(DBG_FUNC, "frame_rate %d fps, frame_drop %d", frame_rate, frame_drop);

        frame_drop = FRAMERATE_MAX;     /* We can allow the maximum here, because dropping is controlled */

        if (usbvision_device_data[usbvision->dev_model].codec == CODEC_WEBCAM) {
                if (usbvision_device_data[usbvision->dev_model].video_norm == V4L2_STD_PAL)
                        frame_drop = 25;
                else
                        frame_drop = 30;
        }

        /* frame_drop = 7; => frame_phase = 1, 5, 9, 13, 17, 21, 25, 0, 4, 8, ...
                => frame_skip = 4;
                => frame_rate = (7 + 1) * 25 / 32 = 200 / 32 = 6.25;

           frame_drop = 9; => frame_phase = 1, 5, 8, 11, 14, 17, 21, 24, 27, 1, 4, 8, ...
            => frame_skip = 4, 3, 3, 3, 3, 4, 3, 3, 3, 3, 4, ...
                => frame_rate = (9 + 1) * 25 / 32 = 250 / 32 = 7.8125;
        */
        err_code = usbvision_write_reg(usbvision, USBVISION_FRM_RATE, frame_drop);
        return err_code;
}


/*
 * usbvision_frames_alloc
 * allocate the required frames
 */
int usbvision_frames_alloc(struct usb_usbvision *usbvision, int number_of_frames)
{
        int i;

        /* needs to be page aligned cause the buffers can be mapped individually! */
        usbvision->max_frame_size = PAGE_ALIGN(usbvision->curwidth *
                                                usbvision->curheight *
                                                usbvision->palette.bytes_per_pixel);

        /* Try to do my best to allocate the frames the user want in the remaining memory */
        usbvision->num_frames = number_of_frames;
        while (usbvision->num_frames > 0) {
                usbvision->fbuf_size = usbvision->num_frames * usbvision->max_frame_size;
                usbvision->fbuf = usbvision_rvmalloc(usbvision->fbuf_size);
                if (usbvision->fbuf)
                        break;
                usbvision->num_frames--;
        }

        /* Allocate all buffers */
        for (i = 0; i < usbvision->num_frames; i++) {
                usbvision->frame[i].index = i;
                usbvision->frame[i].grabstate = frame_state_unused;
                usbvision->frame[i].data = usbvision->fbuf +
                        i * usbvision->max_frame_size;
                /*
                 * Set default sizes for read operation.
                 */
                usbvision->stretch_width = 1;
                usbvision->stretch_height = 1;
                usbvision->frame[i].width = usbvision->curwidth;
                usbvision->frame[i].height = usbvision->curheight;
                usbvision->frame[i].bytes_read = 0;
        }
        PDEBUG(DBG_FUNC, "allocated %d frames (%d bytes per frame)",
                        usbvision->num_frames, usbvision->max_frame_size);
        return usbvision->num_frames;
}

/*
 * usbvision_frames_free
 * frees memory allocated for the frames
 */
void usbvision_frames_free(struct usb_usbvision *usbvision)
{
        /* Have to free all that memory */
        PDEBUG(DBG_FUNC, "free %d frames", usbvision->num_frames);

        if (usbvision->fbuf != NULL) {
                usbvision_rvfree(usbvision->fbuf, usbvision->fbuf_size);
                usbvision->fbuf = NULL;

                usbvision->num_frames = 0;
        }
}
/*
 * usbvision_empty_framequeues()
 * prepare queues for incoming and outgoing frames
 */
void usbvision_empty_framequeues(struct usb_usbvision *usbvision)
{
        u32 i;

        INIT_LIST_HEAD(&(usbvision->inqueue));
        INIT_LIST_HEAD(&(usbvision->outqueue));

        for (i = 0; i < USBVISION_NUMFRAMES; i++) {
                usbvision->frame[i].grabstate = frame_state_unused;
                usbvision->frame[i].bytes_read = 0;
        }
}

/*
 * usbvision_stream_interrupt()
 * stops streaming
 */
int usbvision_stream_interrupt(struct usb_usbvision *usbvision)
{
        int ret = 0;

        /* stop reading from the device */

        usbvision->streaming = stream_interrupt;
        ret = wait_event_timeout(usbvision->wait_stream,
                                 (usbvision->streaming == stream_idle),
                                 msecs_to_jiffies(USBVISION_NUMSBUF*USBVISION_URB_FRAMES));
        return ret;
}

/*
 * usbvision_set_compress_params()
 *
 */

static int usbvision_set_compress_params(struct usb_usbvision *usbvision)
{
        static const char proc[] = "usbvision_set_compresion_params: ";
        int rc;
        unsigned char *value = usbvision->ctrl_urb_buffer;

        value[0] = 0x0F;    /* Intra-Compression cycle */
        value[1] = 0x01;    /* Reg.45 one line per strip */
        value[2] = 0x00;    /* Reg.46 Force intra mode on all new frames */
        value[3] = 0x00;    /* Reg.47 FORCE_UP <- 0 normal operation (not force) */
        value[4] = 0xA2;    /* Reg.48 BUF_THR I'm not sure if this does something in not compressed mode. */
        value[5] = 0x00;    /* Reg.49 DVI_YUV This has nothing to do with compression */

        /* catched values for NT1004 */
        /* value[0] = 0xFF; Never apply intra mode automatically */
        /* value[1] = 0xF1; Use full frame height for virtual strip width; One line per strip */
        /* value[2] = 0x01; Force intra mode on all new frames */
        /* value[3] = 0x00; Strip size 400 Bytes; do not force up */
        /* value[4] = 0xA2; */
        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        rc = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                             USBVISION_OP_CODE,
                             USB_DIR_OUT | USB_TYPE_VENDOR |
                             USB_RECIP_ENDPOINT, 0,
                             (__u16) USBVISION_INTRA_CYC, value, 5, HZ);

        if (rc < 0) {
                printk(KERN_ERR "%sERROR=%d. USBVISION stopped - "
                       "reconnect or reload driver.\n", proc, rc);
                return rc;
        }

        if (usbvision->bridge_type == BRIDGE_NT1004) {
                value[0] =  20; /* PCM Threshold 1 */
                value[1] =  12; /* PCM Threshold 2 */
                value[2] = 255; /* Distortion Threshold inter */
                value[3] = 255; /* Distortion Threshold intra */
                value[4] =  43; /* Max Distortion inter */
                value[5] =  43; /* Max Distortion intra */
        } else {
                value[0] =  20; /* PCM Threshold 1 */
                value[1] =  12; /* PCM Threshold 2 */
                value[2] = 255; /* Distortion Threshold d7-d0 */
                value[3] =   0; /* Distortion Threshold d11-d8 */
                value[4] =  43; /* Max Distortion d7-d0 */
                value[5] =   0; /* Max Distortion d8 */
        }

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        rc = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                             USBVISION_OP_CODE,
                             USB_DIR_OUT | USB_TYPE_VENDOR |
                             USB_RECIP_ENDPOINT, 0,
                             (__u16) USBVISION_PCM_THR1, value, 6, HZ);

        if (rc < 0) {
                printk(KERN_ERR "%sERROR=%d. USBVISION stopped - "
                       "reconnect or reload driver.\n", proc, rc);
        }
        return rc;
}


/*
 * usbvision_set_input()
 *
 * Set the input (saa711x, ...) size x y and other misc input params
 * I've no idea if this parameters are right
 *
 */
int usbvision_set_input(struct usb_usbvision *usbvision)
{
        static const char proc[] = "usbvision_set_input: ";
        int rc;
        unsigned char *value = usbvision->ctrl_urb_buffer;
        unsigned char dvi_yuv_value;

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        /* Set input format expected from decoder*/
        if (usbvision_device_data[usbvision->dev_model].vin_reg1_override) {
                value[0] = usbvision_device_data[usbvision->dev_model].vin_reg1;
        } else if (usbvision_device_data[usbvision->dev_model].codec == CODEC_SAA7113) {
                /* SAA7113 uses 8 bit output */
                value[0] = USBVISION_8_422_SYNC;
        } else {
                /* I'm sure only about d2-d0 [010] 16 bit 4:2:2 usin sync pulses
                 * as that is how saa7111 is configured */
                value[0] = USBVISION_16_422_SYNC;
                /* | USBVISION_VSNC_POL | USBVISION_VCLK_POL);*/
        }

        rc = usbvision_write_reg(usbvision, USBVISION_VIN_REG1, value[0]);
        if (rc < 0) {
                printk(KERN_ERR "%sERROR=%d. USBVISION stopped - "
                       "reconnect or reload driver.\n", proc, rc);
                return rc;
        }


        if (usbvision->tvnorm_id & V4L2_STD_PAL) {
                value[0] = 0xC0;
                value[1] = 0x02;        /* 0x02C0 -> 704 Input video line length */
                value[2] = 0x20;
                value[3] = 0x01;        /* 0x0120 -> 288 Input video n. of lines */
                value[4] = 0x60;
                value[5] = 0x00;        /* 0x0060 -> 96 Input video h offset */
                value[6] = 0x16;
                value[7] = 0x00;        /* 0x0016 -> 22 Input video v offset */
        } else if (usbvision->tvnorm_id & V4L2_STD_SECAM) {
                value[0] = 0xC0;
                value[1] = 0x02;        /* 0x02C0 -> 704 Input video line length */
                value[2] = 0x20;
                value[3] = 0x01;        /* 0x0120 -> 288 Input video n. of lines */
                value[4] = 0x01;
                value[5] = 0x00;        /* 0x0001 -> 01 Input video h offset */
                value[6] = 0x01;
                value[7] = 0x00;        /* 0x0001 -> 01 Input video v offset */
        } else {        /* V4L2_STD_NTSC */
                value[0] = 0xD0;
                value[1] = 0x02;        /* 0x02D0 -> 720 Input video line length */
                value[2] = 0xF0;
                value[3] = 0x00;        /* 0x00F0 -> 240 Input video number of lines */
                value[4] = 0x50;
                value[5] = 0x00;        /* 0x0050 -> 80 Input video h offset */
                value[6] = 0x10;
                value[7] = 0x00;        /* 0x0010 -> 16 Input video v offset */
        }

        /* webcam is only 480 pixels wide, both PAL and NTSC version */
        if (usbvision_device_data[usbvision->dev_model].codec == CODEC_WEBCAM) {
                value[0] = 0xe0;

                value[1] = 0x01;        /* 0x01E0 -> 480 Input video line length */
        }

        if (usbvision_device_data[usbvision->dev_model].x_offset >= 0) {
                value[4] = usbvision_device_data[usbvision->dev_model].x_offset & 0xff;
                value[5] = (usbvision_device_data[usbvision->dev_model].x_offset & 0x0300) >> 8;
        }

        if (adjust_x_offset != -1) {
                value[4] = adjust_x_offset & 0xff;
                value[5] = (adjust_x_offset & 0x0300) >> 8;
        }

        if (usbvision_device_data[usbvision->dev_model].y_offset >= 0) {
                value[6] = usbvision_device_data[usbvision->dev_model].y_offset & 0xff;
                value[7] = (usbvision_device_data[usbvision->dev_model].y_offset & 0x0300) >> 8;
        }

        if (adjust_y_offset != -1) {
                value[6] = adjust_y_offset & 0xff;
                value[7] = (adjust_y_offset & 0x0300) >> 8;
        }

        rc = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                             USBVISION_OP_CODE, /* USBVISION specific code */
                             USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_ENDPOINT, 0,
                             (__u16) USBVISION_LXSIZE_I, value, 8, HZ);
        if (rc < 0) {
                printk(KERN_ERR "%sERROR=%d. USBVISION stopped - "
                       "reconnect or reload driver.\n", proc, rc);
                return rc;
        }


        dvi_yuv_value = 0x00;   /* U comes after V, Ya comes after U/V, Yb comes after Yb */

        if (usbvision_device_data[usbvision->dev_model].dvi_yuv_override) {
                dvi_yuv_value = usbvision_device_data[usbvision->dev_model].dvi_yuv;
        } else if (usbvision_device_data[usbvision->dev_model].codec == CODEC_SAA7113) {
                /* This changes as the fine sync control changes. Further investigation necessary */
                dvi_yuv_value = 0x06;
        }

        return usbvision_write_reg(usbvision, USBVISION_DVI_YUV, dvi_yuv_value);
}


/*
 * usbvision_set_dram_settings()
 *
 * Set the buffer address needed by the usbvision dram to operate
 * This values has been taken with usbsnoop.
 *
 */

static int usbvision_set_dram_settings(struct usb_usbvision *usbvision)
{
        unsigned char *value = usbvision->ctrl_urb_buffer;
        int rc;

        if (usbvision->isoc_mode == ISOC_MODE_COMPRESS) {
                value[0] = 0x42;
                value[1] = 0x71;
                value[2] = 0xff;
                value[3] = 0x00;
                value[4] = 0x98;
                value[5] = 0xe0;
                value[6] = 0x71;
                value[7] = 0xff;
                /* UR:  0x0E200-0x3FFFF = 204288 Words (1 Word = 2 Byte) */
                /* FDL: 0x00000-0x0E099 =  57498 Words */
                /* VDW: 0x0E3FF-0x3FFFF */
        } else {
                value[0] = 0x42;
                value[1] = 0x00;
                value[2] = 0xff;
                value[3] = 0x00;
                value[4] = 0x00;
                value[5] = 0x00;
                value[6] = 0x00;
                value[7] = 0xff;
        }
        /* These are the values of the address of the video buffer,
         * they have to be loaded into the USBVISION_DRM_PRM1-8
         *
         * Start address of video output buffer for read:       drm_prm1-2 -> 0x00000
         * End address of video output buffer for read:         drm_prm1-3 -> 0x1ffff
         * Start address of video frame delay buffer:           drm_prm1-4 -> 0x20000
         *    Only used in compressed mode
         * End address of video frame delay buffer:             drm_prm1-5-6 -> 0x3ffff
         *    Only used in compressed mode
         * Start address of video output buffer for write:      drm_prm1-7 -> 0x00000
         * End address of video output buffer for write:        drm_prm1-8 -> 0x1ffff
         */

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return 0;

        rc = usb_control_msg(usbvision->dev, usb_sndctrlpipe(usbvision->dev, 1),
                             USBVISION_OP_CODE, /* USBVISION specific code */
                             USB_DIR_OUT | USB_TYPE_VENDOR |
                             USB_RECIP_ENDPOINT, 0,
                             (__u16) USBVISION_DRM_PRM1, value, 8, HZ);

        if (rc < 0) {
                dev_err(&usbvision->dev->dev, "%s: ERROR=%d\n", __func__, rc);
                return rc;
        }

        /* Restart the video buffer logic */
        rc = usbvision_write_reg(usbvision, USBVISION_DRM_CONT, USBVISION_RES_UR |
                                   USBVISION_RES_FDL | USBVISION_RES_VDW);
        if (rc < 0)
                return rc;
        rc = usbvision_write_reg(usbvision, USBVISION_DRM_CONT, 0x00);

        return rc;
}

/*
 * ()
 *
 * Power on the device, enables suspend-resume logic
 * &  reset the isoc End-Point
 *
 */

int usbvision_power_on(struct usb_usbvision *usbvision)
{
        int err_code = 0;

        PDEBUG(DBG_FUNC, "");

        usbvision_write_reg(usbvision, USBVISION_PWR_REG, USBVISION_SSPND_EN);
        usbvision_write_reg(usbvision, USBVISION_PWR_REG,
                        USBVISION_SSPND_EN | USBVISION_RES2);

        if (usbvision_device_data[usbvision->dev_model].codec == CODEC_WEBCAM) {
                usbvision_write_reg(usbvision, USBVISION_VIN_REG1,
                                USBVISION_16_422_SYNC | USBVISION_HVALID_PO);
                usbvision_write_reg(usbvision, USBVISION_VIN_REG2,
                                USBVISION_NOHVALID | USBVISION_KEEP_BLANK);
        }
        usbvision_write_reg(usbvision, USBVISION_PWR_REG,
                        USBVISION_SSPND_EN | USBVISION_PWR_VID);
        mdelay(10);
        err_code = usbvision_write_reg(usbvision, USBVISION_PWR_REG,
                        USBVISION_SSPND_EN | USBVISION_PWR_VID | USBVISION_RES2);
        if (err_code == 1)
                usbvision->power = 1;
        PDEBUG(DBG_FUNC, "%s: err_code %d", (err_code < 0) ? "ERROR" : "power is on", err_code);
        return err_code;
}


/*
 * usbvision_begin_streaming()
 * Sure you have to put bit 7 to 0, if not incoming frames are droped, but no
 * idea about the rest
 */
int usbvision_begin_streaming(struct usb_usbvision *usbvision)
{
        if (usbvision->isoc_mode == ISOC_MODE_COMPRESS)
                usbvision_init_compression(usbvision);
        return usbvision_write_reg(usbvision, USBVISION_VIN_REG2,
                USBVISION_NOHVALID | usbvision->vin_reg2_preset);
}

/*
 * usbvision_restart_isoc()
 * Not sure yet if touching here PWR_REG make loose the config
 */

int usbvision_restart_isoc(struct usb_usbvision *usbvision)
{
        int ret;

        ret = usbvision_write_reg(usbvision, USBVISION_PWR_REG,
                              USBVISION_SSPND_EN | USBVISION_PWR_VID);
        if (ret < 0)
                return ret;
        ret = usbvision_write_reg(usbvision, USBVISION_PWR_REG,
                              USBVISION_SSPND_EN | USBVISION_PWR_VID |
                              USBVISION_RES2);
        if (ret < 0)
                return ret;
        ret = usbvision_write_reg(usbvision, USBVISION_VIN_REG2,
                              USBVISION_KEEP_BLANK | USBVISION_NOHVALID |
                                  usbvision->vin_reg2_preset);
        if (ret < 0)
                return ret;

        /* TODO: schedule timeout */
        while ((usbvision_read_reg(usbvision, USBVISION_STATUS_REG) & 0x01) != 1)
                ;

        return 0;
}

int usbvision_audio_off(struct usb_usbvision *usbvision)
{
        if (usbvision_write_reg(usbvision, USBVISION_IOPIN_REG, USBVISION_AUDIO_MUTE) < 0) {
                printk(KERN_ERR "usbvision_audio_off: can't write reg\n");
                return -1;
        }
        usbvision->audio_mute = 0;
        usbvision->audio_channel = USBVISION_AUDIO_MUTE;
        return 0;
}

int usbvision_set_audio(struct usb_usbvision *usbvision, int audio_channel)
{
        if (!usbvision->audio_mute) {
                if (usbvision_write_reg(usbvision, USBVISION_IOPIN_REG, audio_channel) < 0) {
                        printk(KERN_ERR "usbvision_set_audio: can't write iopin register for audio switching\n");
                        return -1;
                }
        }
        usbvision->audio_channel = audio_channel;
        return 0;
}

int usbvision_setup(struct usb_usbvision *usbvision, int format)
{
        if (usbvision_device_data[usbvision->dev_model].codec == CODEC_WEBCAM)
                usbvision_init_webcam(usbvision);
        usbvision_set_video_format(usbvision, format);
        usbvision_set_dram_settings(usbvision);
        usbvision_set_compress_params(usbvision);
        usbvision_set_input(usbvision);
        usbvision_set_output(usbvision, MAX_USB_WIDTH, MAX_USB_HEIGHT);
        usbvision_restart_isoc(usbvision);

        /* cosas del PCM */
        return USBVISION_IS_OPERATIONAL(usbvision);
}

int usbvision_set_alternate(struct usb_usbvision *dev)
{
        int err_code, prev_alt = dev->iface_alt;
        int i;

        dev->iface_alt = 0;
        for (i = 0; i < dev->num_alt; i++)
                if (dev->alt_max_pkt_size[i] > dev->alt_max_pkt_size[dev->iface_alt])
                        dev->iface_alt = i;

        if (dev->iface_alt != prev_alt) {
                dev->isoc_packet_size = dev->alt_max_pkt_size[dev->iface_alt];
                PDEBUG(DBG_FUNC, "setting alternate %d with max_packet_size=%u",
                                dev->iface_alt, dev->isoc_packet_size);
                err_code = usb_set_interface(dev->dev, dev->iface, dev->iface_alt);
                if (err_code < 0) {
                        dev_err(&dev->dev->dev,
                                "cannot change alternate number to %d (error=%i)\n",
                                        dev->iface_alt, err_code);
                        return err_code;
                }
        }

        PDEBUG(DBG_ISOC, "ISO Packet Length:%d", dev->isoc_packet_size);

        return 0;
}

/*
 * usbvision_init_isoc()
 *
 */
int usbvision_init_isoc(struct usb_usbvision *usbvision)
{
        struct usb_device *dev = usbvision->dev;
        int buf_idx, err_code, reg_value;
        int sb_size;

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return -EFAULT;

        usbvision->cur_frame = NULL;
        scratch_reset(usbvision);

        /* Alternate interface 1 is is the biggest frame size */
        err_code = usbvision_set_alternate(usbvision);
        if (err_code < 0) {
                usbvision->last_error = err_code;
                return -EBUSY;
        }
        sb_size = USBVISION_URB_FRAMES * usbvision->isoc_packet_size;

        reg_value = (16 - usbvision_read_reg(usbvision,
                                            USBVISION_ALTER_REG)) & 0x0F;

        usbvision->usb_bandwidth = reg_value >> 1;
        PDEBUG(DBG_ISOC, "USB Bandwidth Usage: %dMbit/Sec",
               usbvision->usb_bandwidth);



        /* We double buffer the Iso lists */

        for (buf_idx = 0; buf_idx < USBVISION_NUMSBUF; buf_idx++) {
                int j, k;
                struct urb *urb;

                urb = usb_alloc_urb(USBVISION_URB_FRAMES, GFP_KERNEL);
                if (urb == NULL)
                        return -ENOMEM;
                usbvision->sbuf[buf_idx].urb = urb;
                usbvision->sbuf[buf_idx].data =
                        usb_alloc_coherent(usbvision->dev,
                                           sb_size,
                                           GFP_KERNEL,
                                           &urb->transfer_dma);
                urb->dev = dev;
                urb->context = usbvision;
                urb->pipe = usb_rcvisocpipe(dev, usbvision->video_endp);
                urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
                urb->interval = 1;
                urb->transfer_buffer = usbvision->sbuf[buf_idx].data;
                urb->complete = usbvision_isoc_irq;
                urb->number_of_packets = USBVISION_URB_FRAMES;
                urb->transfer_buffer_length =
                    usbvision->isoc_packet_size * USBVISION_URB_FRAMES;
                for (j = k = 0; j < USBVISION_URB_FRAMES; j++,
                     k += usbvision->isoc_packet_size) {
                        urb->iso_frame_desc[j].offset = k;
                        urb->iso_frame_desc[j].length =
                                usbvision->isoc_packet_size;
                }
        }

        /* Submit all URBs */
        for (buf_idx = 0; buf_idx < USBVISION_NUMSBUF; buf_idx++) {
                err_code = usb_submit_urb(usbvision->sbuf[buf_idx].urb,
                                         GFP_KERNEL);
                if (err_code) {
                        dev_err(&usbvision->dev->dev,
                                "%s: usb_submit_urb(%d) failed: error %d\n",
                                        __func__, buf_idx, err_code);
                }
        }

        usbvision->streaming = stream_idle;
        PDEBUG(DBG_ISOC, "%s: streaming=1 usbvision->video_endp=$%02x",
               __func__,
               usbvision->video_endp);
        return 0;
}

/*
 * usbvision_stop_isoc()
 *
 * This procedure stops streaming and deallocates URBs. Then it
 * activates zero-bandwidth alt. setting of the video interface.
 *
 */
void usbvision_stop_isoc(struct usb_usbvision *usbvision)
{
        int buf_idx, err_code, reg_value;
        int sb_size = USBVISION_URB_FRAMES * usbvision->isoc_packet_size;

        if ((usbvision->streaming == stream_off) || (usbvision->dev == NULL))
                return;

        /* Unschedule all of the iso td's */
        for (buf_idx = 0; buf_idx < USBVISION_NUMSBUF; buf_idx++) {
                usb_kill_urb(usbvision->sbuf[buf_idx].urb);
                if (usbvision->sbuf[buf_idx].data) {
                        usb_free_coherent(usbvision->dev,
                                          sb_size,
                                          usbvision->sbuf[buf_idx].data,
                                          usbvision->sbuf[buf_idx].urb->transfer_dma);
                }
                usb_free_urb(usbvision->sbuf[buf_idx].urb);
                usbvision->sbuf[buf_idx].urb = NULL;
        }

        PDEBUG(DBG_ISOC, "%s: streaming=stream_off\n", __func__);
        usbvision->streaming = stream_off;

        if (!usbvision->remove_pending) {
                /* Set packet size to 0 */
                usbvision->iface_alt = 0;
                err_code = usb_set_interface(usbvision->dev, usbvision->iface,
                                            usbvision->iface_alt);
                if (err_code < 0) {
                        dev_err(&usbvision->dev->dev,
                                "%s: usb_set_interface() failed: error %d\n",
                                        __func__, err_code);
                        usbvision->last_error = err_code;
                }
                reg_value = (16-usbvision_read_reg(usbvision, USBVISION_ALTER_REG)) & 0x0F;
                usbvision->isoc_packet_size =
                        (reg_value == 0) ? 0 : (reg_value * 64) - 1;
                PDEBUG(DBG_ISOC, "ISO Packet Length:%d",
                       usbvision->isoc_packet_size);

                usbvision->usb_bandwidth = reg_value >> 1;
                PDEBUG(DBG_ISOC, "USB Bandwidth Usage: %dMbit/Sec",
                       usbvision->usb_bandwidth);
        }
}

int usbvision_muxsel(struct usb_usbvision *usbvision, int channel)
{
        /* inputs #0 and #3 are constant for every SAA711x. */
        /* inputs #1 and #2 are variable for SAA7111 and SAA7113 */
        int mode[4] = { SAA7115_COMPOSITE0, 0, 0, SAA7115_COMPOSITE3 };
        int audio[] = { 1, 0, 0, 0 };
        /* channel 0 is TV with audiochannel 1 (tuner mono) */
        /* channel 1 is Composite with audio channel 0 (line in) */
        /* channel 2 is S-Video with audio channel 0 (line in) */
        /* channel 3 is additional video inputs to the device with audio channel 0 (line in) */

        RESTRICT_TO_RANGE(channel, 0, usbvision->video_inputs);
        usbvision->ctl_input = channel;

        /* set the new channel */
        /* Regular USB TV Tuners -> channel: 0 = Television, 1 = Composite, 2 = S-Video */
        /* Four video input devices -> channel: 0 = Chan White, 1 = Chan Green, 2 = Chan Yellow, 3 = Chan Red */

        switch (usbvision_device_data[usbvision->dev_model].codec) {
        case CODEC_SAA7113:
                mode[1] = SAA7115_COMPOSITE2;
                if (switch_svideo_input) {
                        /* To handle problems with S-Video Input for
                         * some devices.  Use switch_svideo_input
                         * parameter when loading the module.*/
                        mode[2] = SAA7115_COMPOSITE1;
                } else {
                        mode[2] = SAA7115_SVIDEO1;
                }
                break;
        case CODEC_SAA7111:
        default:
                /* modes for saa7111 */
                mode[1] = SAA7115_COMPOSITE1;
                mode[2] = SAA7115_SVIDEO1;
                break;
        }
        call_all(usbvision, video, s_routing, mode[channel], 0, 0);
        usbvision_set_audio(usbvision, audio[channel]);
        return 0;
}