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w9968cf.c

/***************************************************************************
 * Video4Linux driver for W996[87]CF JPEG USB Dual Mode Camera Chip.       *
 *                                                                         *
 * Copyright (C) 2002-2004 by Luca Risolia <luca.risolia@studio.unibo.it>  *
 *                                                                         *
 * - Memory management code from bttv driver by Ralph Metzler,             *
 *   Marcus Metzler and Gerd Knorr.                                        *
 * - I2C interface to kernel, high-level image sensor control routines and *
 *   some symbolic names from OV511 driver by Mark W. McClelland.          *
 * - Low-level I2C fast write function by Piotr Czerczak.                  *
 * - Low-level I2C read function by Frederic Jouault.                      *
 *                                                                         *
 * 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/module.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/ioctl.h>
#include <linux/delay.h>
#include <linux/stddef.h>
#include <asm/page.h>
#include <asm/uaccess.h>
#include <linux/page-flags.h>
#include <linux/videodev.h>
#include <media/v4l2-ioctl.h>

#include "w9968cf.h"
#include "w9968cf_decoder.h"

static struct w9968cf_vpp_t* w9968cf_vpp;
static DECLARE_WAIT_QUEUE_HEAD(w9968cf_vppmod_wait);

static LIST_HEAD(w9968cf_dev_list); /* head of V4L registered cameras list */
static DEFINE_MUTEX(w9968cf_devlist_mutex); /* semaphore for list traversal */

static DECLARE_RWSEM(w9968cf_disconnect); /* prevent races with open() */


/****************************************************************************
 * Module macros and parameters                                             *
 ****************************************************************************/

MODULE_DEVICE_TABLE(usb, winbond_id_table);

MODULE_AUTHOR(W9968CF_MODULE_AUTHOR" "W9968CF_AUTHOR_EMAIL);
MODULE_DESCRIPTION(W9968CF_MODULE_NAME);
MODULE_VERSION(W9968CF_MODULE_VERSION);
MODULE_LICENSE(W9968CF_MODULE_LICENSE);
MODULE_SUPPORTED_DEVICE("Video");

static unsigned short simcams = W9968CF_SIMCAMS;
static short video_nr[]={[0 ... W9968CF_MAX_DEVICES-1] = -1}; /*-1=first free*/
static unsigned int packet_size[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                             W9968CF_PACKET_SIZE};
static unsigned short max_buffers[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                               W9968CF_BUFFERS};
static int double_buffer[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                        W9968CF_DOUBLE_BUFFER};
static int clamping[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_CLAMPING};
static unsigned short filter_type[]= {[0 ... W9968CF_MAX_DEVICES-1] =
                              W9968CF_FILTER_TYPE};
static int largeview[]= {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_LARGEVIEW};
static unsigned short decompression[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                               W9968CF_DECOMPRESSION};
static int upscaling[]= {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_UPSCALING};
static unsigned short force_palette[] = {[0 ... W9968CF_MAX_DEVICES-1] = 0};
static int force_rgb[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_FORCE_RGB};
static int autobright[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_AUTOBRIGHT};
static int autoexp[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_AUTOEXP};
static unsigned short lightfreq[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                             W9968CF_LIGHTFREQ};
static int bandingfilter[] = {[0 ... W9968CF_MAX_DEVICES-1]=
                        W9968CF_BANDINGFILTER};
static short clockdiv[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_CLOCKDIV};
static int backlight[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_BACKLIGHT};
static int mirror[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_MIRROR};
static int monochrome[] = {[0 ... W9968CF_MAX_DEVICES-1]=W9968CF_MONOCHROME};
static unsigned int brightness[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                            W9968CF_BRIGHTNESS};
static unsigned int hue[] = {[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_HUE};
static unsigned int colour[]={[0 ... W9968CF_MAX_DEVICES-1] = W9968CF_COLOUR};
static unsigned int contrast[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                          W9968CF_CONTRAST};
static unsigned int whiteness[] = {[0 ... W9968CF_MAX_DEVICES-1] =
                           W9968CF_WHITENESS};
#ifdef W9968CF_DEBUG
static unsigned short debug = W9968CF_DEBUG_LEVEL;
static int specific_debug = W9968CF_SPECIFIC_DEBUG;
#endif

static unsigned int param_nv[24]; /* number of values per parameter */

module_param(simcams, ushort, 0644);
module_param_array(video_nr, short, &param_nv[0], 0444);
module_param_array(packet_size, uint, &param_nv[1], 0444);
module_param_array(max_buffers, ushort, &param_nv[2], 0444);
module_param_array(double_buffer, bool, &param_nv[3], 0444);
module_param_array(clamping, bool, &param_nv[4], 0444);
module_param_array(filter_type, ushort, &param_nv[5], 0444);
module_param_array(largeview, bool, &param_nv[6], 0444);
module_param_array(decompression, ushort, &param_nv[7], 0444);
module_param_array(upscaling, bool, &param_nv[8], 0444);
module_param_array(force_palette, ushort, &param_nv[9], 0444);
module_param_array(force_rgb, ushort, &param_nv[10], 0444);
module_param_array(autobright, bool, &param_nv[11], 0444);
module_param_array(autoexp, bool, &param_nv[12], 0444);
module_param_array(lightfreq, ushort, &param_nv[13], 0444);
module_param_array(bandingfilter, bool, &param_nv[14], 0444);
module_param_array(clockdiv, short, &param_nv[15], 0444);
module_param_array(backlight, bool, &param_nv[16], 0444);
module_param_array(mirror, bool, &param_nv[17], 0444);
module_param_array(monochrome, bool, &param_nv[18], 0444);
module_param_array(brightness, uint, &param_nv[19], 0444);
module_param_array(hue, uint, &param_nv[20], 0444);
module_param_array(colour, uint, &param_nv[21], 0444);
module_param_array(contrast, uint, &param_nv[22], 0444);
module_param_array(whiteness, uint, &param_nv[23], 0444);
#ifdef W9968CF_DEBUG
module_param(debug, ushort, 0644);
module_param(specific_debug, bool, 0644);
#endif

MODULE_PARM_DESC(simcams,
             "\n<n> Number of cameras allowed to stream simultaneously."
             "\nn may vary from 0 to "
             __MODULE_STRING(W9968CF_MAX_DEVICES)"."
             "\nDefault value is "__MODULE_STRING(W9968CF_SIMCAMS)"."
             "\n");
MODULE_PARM_DESC(video_nr,
             "\n<-1|n[,...]> Specify V4L minor mode number."
             "\n -1 = use next available (default)"
             "\n  n = use minor number n (integer >= 0)"
             "\nYou can specify up to "__MODULE_STRING(W9968CF_MAX_DEVICES)
             " cameras this way."
             "\nFor example:"
             "\nvideo_nr=-1,2,-1 would assign minor number 2 to"
             "\nthe second camera and use auto for the first"
             "\none and for every other camera."
             "\n");
MODULE_PARM_DESC(packet_size,
             "\n<n[,...]> Specify the maximum data payload"
             "\nsize in bytes for alternate settings, for each device."
             "\nn is scaled between 63 and 1023 "
             "(default is "__MODULE_STRING(W9968CF_PACKET_SIZE)")."
             "\n");
MODULE_PARM_DESC(max_buffers,
             "\n<n[,...]> For advanced users."
             "\nSpecify the maximum number of video frame buffers"
             "\nto allocate for each device, from 2 to "
             __MODULE_STRING(W9968CF_MAX_BUFFERS)
             ". (default is "__MODULE_STRING(W9968CF_BUFFERS)")."
             "\n");
MODULE_PARM_DESC(double_buffer,
             "\n<0|1[,...]> "
             "Hardware double buffering: 0 disabled, 1 enabled."
             "\nIt should be enabled if you want smooth video output: if"
             "\nyou obtain out of sync. video, disable it, or try to"
             "\ndecrease the 'clockdiv' module parameter value."
             "\nDefault value is "__MODULE_STRING(W9968CF_DOUBLE_BUFFER)
             " for every device."
             "\n");
MODULE_PARM_DESC(clamping,
             "\n<0|1[,...]> Video data clamping: 0 disabled, 1 enabled."
             "\nDefault value is "__MODULE_STRING(W9968CF_CLAMPING)
             " for every device."
             "\n");
MODULE_PARM_DESC(filter_type,
             "\n<0|1|2[,...]> Video filter type."
             "\n0 none, 1 (1-2-1) 3-tap filter, "
             "2 (2-3-6-3-2) 5-tap filter."
             "\nDefault value is "__MODULE_STRING(W9968CF_FILTER_TYPE)
             " for every device."
             "\nThe filter is used to reduce noise and aliasing artifacts"
             "\nproduced by the CCD or CMOS image sensor, and the scaling"
             " process."
             "\n");
MODULE_PARM_DESC(largeview,
             "\n<0|1[,...]> Large view: 0 disabled, 1 enabled."
             "\nDefault value is "__MODULE_STRING(W9968CF_LARGEVIEW)
             " for every device."
             "\n");
MODULE_PARM_DESC(upscaling,
             "\n<0|1[,...]> Software scaling (for non-compressed video):"
             "\n0 disabled, 1 enabled."
             "\nDisable it if you have a slow CPU or you don't have"
             " enough memory."
             "\nDefault value is "__MODULE_STRING(W9968CF_UPSCALING)
             " for every device."
             "\nIf 'w9968cf-vpp' is not present, this parameter is"
             " set to 0."
             "\n");
MODULE_PARM_DESC(decompression,
             "\n<0|1|2[,...]> Software video decompression:"
             "\n- 0 disables decompression (doesn't allow formats needing"
             " decompression)"
             "\n- 1 forces decompression (allows formats needing"
             " decompression only);"
             "\n- 2 allows any permitted formats."
             "\nFormats supporting compressed video are YUV422P and"
             " YUV420P/YUV420 "
             "\nin any resolutions where both width and height are "
             "a multiple of 16."
             "\nDefault value is "__MODULE_STRING(W9968CF_DECOMPRESSION)
             " for every device."
             "\nIf 'w9968cf-vpp' is not present, forcing decompression is "
             "\nnot allowed; in this case this parameter is set to 2."
             "\n");
MODULE_PARM_DESC(force_palette,
             "\n<0"
             "|" __MODULE_STRING(VIDEO_PALETTE_UYVY)
             "|" __MODULE_STRING(VIDEO_PALETTE_YUV420)
             "|" __MODULE_STRING(VIDEO_PALETTE_YUV422P)
             "|" __MODULE_STRING(VIDEO_PALETTE_YUV420P)
             "|" __MODULE_STRING(VIDEO_PALETTE_YUYV)
             "|" __MODULE_STRING(VIDEO_PALETTE_YUV422)
             "|" __MODULE_STRING(VIDEO_PALETTE_GREY)
             "|" __MODULE_STRING(VIDEO_PALETTE_RGB555)
             "|" __MODULE_STRING(VIDEO_PALETTE_RGB565)
             "|" __MODULE_STRING(VIDEO_PALETTE_RGB24)
             "|" __MODULE_STRING(VIDEO_PALETTE_RGB32)
             "[,...]>"
             " Force picture palette."
             "\nIn order:"
             "\n- 0 allows any of the following formats:"
             "\n- UYVY    16 bpp - Original video, compression disabled"
             "\n- YUV420  12 bpp - Original video, compression enabled"
             "\n- YUV422P 16 bpp - Original video, compression enabled"
             "\n- YUV420P 12 bpp - Original video, compression enabled"
             "\n- YUVY    16 bpp - Software conversion from UYVY"
             "\n- YUV422  16 bpp - Software conversion from UYVY"
             "\n- GREY     8 bpp - Software conversion from UYVY"
             "\n- RGB555  16 bpp - Software conversion from UYVY"
             "\n- RGB565  16 bpp - Software conversion from UYVY"
             "\n- RGB24   24 bpp - Software conversion from UYVY"
             "\n- RGB32   32 bpp - Software conversion from UYVY"
             "\nWhen not 0, this parameter will override 'decompression'."
             "\nDefault value is 0 for every device."
             "\nInitial palette is "
             __MODULE_STRING(W9968CF_PALETTE_DECOMP_ON)"."
             "\nIf 'w9968cf-vpp' is not present, this parameter is"
             " set to 9 (UYVY)."
             "\n");
MODULE_PARM_DESC(force_rgb,
             "\n<0|1[,...]> Read RGB video data instead of BGR:"
             "\n 1 = use RGB component ordering."
             "\n 0 = use BGR component ordering."
             "\nThis parameter has effect when using RGBX palettes only."
             "\nDefault value is "__MODULE_STRING(W9968CF_FORCE_RGB)
             " for every device."
             "\n");
MODULE_PARM_DESC(autobright,
             "\n<0|1[,...]> Image sensor automatically changes brightness:"
             "\n 0 = no, 1 = yes"
             "\nDefault value is "__MODULE_STRING(W9968CF_AUTOBRIGHT)
             " for every device."
             "\n");
MODULE_PARM_DESC(autoexp,
             "\n<0|1[,...]> Image sensor automatically changes exposure:"
             "\n 0 = no, 1 = yes"
             "\nDefault value is "__MODULE_STRING(W9968CF_AUTOEXP)
             " for every device."
             "\n");
MODULE_PARM_DESC(lightfreq,
             "\n<50|60[,...]> Light frequency in Hz:"
             "\n 50 for European and Asian lighting,"
             " 60 for American lighting."
             "\nDefault value is "__MODULE_STRING(W9968CF_LIGHTFREQ)
             " for every device."
             "\n");
MODULE_PARM_DESC(bandingfilter,
             "\n<0|1[,...]> Banding filter to reduce effects of"
             " fluorescent lighting:"
             "\n 0 disabled, 1 enabled."
             "\nThis filter tries to reduce the pattern of horizontal"
             "\nlight/dark bands caused by some (usually fluorescent)"
             " lighting."
             "\nDefault value is "__MODULE_STRING(W9968CF_BANDINGFILTER)
             " for every device."
             "\n");
MODULE_PARM_DESC(clockdiv,
             "\n<-1|n[,...]> "
             "Force pixel clock divisor to a specific value (for experts):"
             "\n  n may vary from 0 to 127."
             "\n -1 for automatic value."
             "\nSee also the 'double_buffer' module parameter."
             "\nDefault value is "__MODULE_STRING(W9968CF_CLOCKDIV)
             " for every device."
             "\n");
MODULE_PARM_DESC(backlight,
             "\n<0|1[,...]> Objects are lit from behind:"
             "\n 0 = no, 1 = yes"
             "\nDefault value is "__MODULE_STRING(W9968CF_BACKLIGHT)
             " for every device."
             "\n");
MODULE_PARM_DESC(mirror,
             "\n<0|1[,...]> Reverse image horizontally:"
             "\n 0 = no, 1 = yes"
             "\nDefault value is "__MODULE_STRING(W9968CF_MIRROR)
             " for every device."
             "\n");
MODULE_PARM_DESC(monochrome,
             "\n<0|1[,...]> Use image sensor as monochrome sensor:"
             "\n 0 = no, 1 = yes"
             "\nNot all the sensors support monochrome color."
             "\nDefault value is "__MODULE_STRING(W9968CF_MONOCHROME)
             " for every device."
             "\n");
MODULE_PARM_DESC(brightness,
             "\n<n[,...]> Set picture brightness (0-65535)."
             "\nDefault value is "__MODULE_STRING(W9968CF_BRIGHTNESS)
             " for every device."
             "\nThis parameter has no effect if 'autobright' is enabled."
             "\n");
MODULE_PARM_DESC(hue,
             "\n<n[,...]> Set picture hue (0-65535)."
             "\nDefault value is "__MODULE_STRING(W9968CF_HUE)
             " for every device."
             "\n");
MODULE_PARM_DESC(colour,
             "\n<n[,...]> Set picture saturation (0-65535)."
             "\nDefault value is "__MODULE_STRING(W9968CF_COLOUR)
             " for every device."
             "\n");
MODULE_PARM_DESC(contrast,
             "\n<n[,...]> Set picture contrast (0-65535)."
             "\nDefault value is "__MODULE_STRING(W9968CF_CONTRAST)
             " for every device."
             "\n");
MODULE_PARM_DESC(whiteness,
             "\n<n[,...]> Set picture whiteness (0-65535)."
             "\nDefault value is "__MODULE_STRING(W9968CF_WHITENESS)
             " for every device."
             "\n");
#ifdef W9968CF_DEBUG
MODULE_PARM_DESC(debug,
             "\n<n> Debugging information level, from 0 to 6:"
             "\n0 = none (use carefully)"
             "\n1 = critical errors"
             "\n2 = significant informations"
             "\n3 = configuration or general messages"
             "\n4 = warnings"
             "\n5 = called functions"
             "\n6 = function internals"
             "\nLevel 5 and 6 are useful for testing only, when only "
             "one device is used."
             "\nDefault value is "__MODULE_STRING(W9968CF_DEBUG_LEVEL)"."
             "\n");
MODULE_PARM_DESC(specific_debug,
             "\n<0|1> Enable or disable specific debugging messages:"
             "\n0 = print messages concerning every level"
             " <= 'debug' level."
             "\n1 = print messages concerning the level"
             " indicated by 'debug'."
             "\nDefault value is "
             __MODULE_STRING(W9968CF_SPECIFIC_DEBUG)"."
             "\n");
#endif /* W9968CF_DEBUG */



/****************************************************************************
 * Some prototypes                                                          *
 ****************************************************************************/

/* Video4linux interface */
static const struct v4l2_file_operations w9968cf_fops;
static int w9968cf_open(struct file *);
static int w9968cf_release(struct file *);
static int w9968cf_mmap(struct file *, struct vm_area_struct *);
static long w9968cf_ioctl(struct file *, unsigned, unsigned long);
static ssize_t w9968cf_read(struct file *, char __user *, size_t, loff_t *);
static long w9968cf_v4l_ioctl(struct file *, unsigned int,
                       void __user *);

/* USB-specific */
static int w9968cf_start_transfer(struct w9968cf_device*);
static int w9968cf_stop_transfer(struct w9968cf_device*);
static int w9968cf_write_reg(struct w9968cf_device*, u16 value, u16 index);
static int w9968cf_read_reg(struct w9968cf_device*, u16 index);
static int w9968cf_write_fsb(struct w9968cf_device*, u16* data);
static int w9968cf_write_sb(struct w9968cf_device*, u16 value);
static int w9968cf_read_sb(struct w9968cf_device*);
static int w9968cf_upload_quantizationtables(struct w9968cf_device*);
static void w9968cf_urb_complete(struct urb *urb);

/* Low-level I2C (SMBus) I/O */
static int w9968cf_smbus_start(struct w9968cf_device*);
static int w9968cf_smbus_stop(struct w9968cf_device*);
static int w9968cf_smbus_write_byte(struct w9968cf_device*, u8 v);
static int w9968cf_smbus_read_byte(struct w9968cf_device*, u8* v);
static int w9968cf_smbus_write_ack(struct w9968cf_device*);
static int w9968cf_smbus_read_ack(struct w9968cf_device*);
static int w9968cf_smbus_refresh_bus(struct w9968cf_device*);
static int w9968cf_i2c_adap_read_byte(struct w9968cf_device* cam,
                              u16 address, u8* value);
static int w9968cf_i2c_adap_read_byte_data(struct w9968cf_device*, u16 address,
                                 u8 subaddress, u8* value);
static int w9968cf_i2c_adap_write_byte(struct w9968cf_device*,
                               u16 address, u8 subaddress);
static int w9968cf_i2c_adap_fastwrite_byte_data(struct w9968cf_device*,
                                    u16 address, u8 subaddress,
                                    u8 value);

/* I2C interface to kernel */
static int w9968cf_i2c_init(struct w9968cf_device*);
static int w9968cf_i2c_smbus_xfer(struct i2c_adapter*, u16 addr,
                          unsigned short flags, char read_write,
                          u8 command, int size, union i2c_smbus_data*);
static u32 w9968cf_i2c_func(struct i2c_adapter*);

/* Memory management */
static void* rvmalloc(unsigned long size);
static void rvfree(void *mem, unsigned long size);
static void w9968cf_deallocate_memory(struct w9968cf_device*);
static int  w9968cf_allocate_memory(struct w9968cf_device*);

/* High-level image sensor control functions */
static int w9968cf_sensor_set_control(struct w9968cf_device*,int cid,int val);
static int w9968cf_sensor_get_control(struct w9968cf_device*,int cid,int *val);
static int w9968cf_sensor_cmd(struct w9968cf_device*,
                        unsigned int cmd, void *arg);
static int w9968cf_sensor_init(struct w9968cf_device*);
static int w9968cf_sensor_update_settings(struct w9968cf_device*);
static int w9968cf_sensor_get_picture(struct w9968cf_device*);
static int w9968cf_sensor_update_picture(struct w9968cf_device*,
                               struct video_picture pict);

/* Other helper functions */
static void w9968cf_configure_camera(struct w9968cf_device*,struct usb_device*,
                             enum w9968cf_model_id,
                             const unsigned short dev_nr);
static void w9968cf_adjust_configuration(struct w9968cf_device*);
static int w9968cf_turn_on_led(struct w9968cf_device*);
static int w9968cf_init_chip(struct w9968cf_device*);
static inline u16 w9968cf_valid_palette(u16 palette);
static inline u16 w9968cf_valid_depth(u16 palette);
static inline u8 w9968cf_need_decompression(u16 palette);
static int w9968cf_set_picture(struct w9968cf_device*, struct video_picture);
static int w9968cf_set_window(struct w9968cf_device*, struct video_window);
static int w9968cf_postprocess_frame(struct w9968cf_device*,
                             struct w9968cf_frame_t*);
static int w9968cf_adjust_window_size(struct w9968cf_device*, u32 *w, u32 *h);
static void w9968cf_init_framelist(struct w9968cf_device*);
static void w9968cf_push_frame(struct w9968cf_device*, u8 f_num);
static void w9968cf_pop_frame(struct w9968cf_device*,struct w9968cf_frame_t**);
static void w9968cf_release_resources(struct w9968cf_device*);



/****************************************************************************
 * Symbolic names                                                           *
 ****************************************************************************/

/* Used to represent a list of values and their respective symbolic names */
00476 struct w9968cf_symbolic_list {
      const int num;
      const char *name;
};

/*--------------------------------------------------------------------------
  Returns the name of the matching element in the symbolic_list array. The
  end of the list must be marked with an element that has a NULL name.
  --------------------------------------------------------------------------*/
static inline const char *
symbolic(struct w9968cf_symbolic_list list[], const int num)
{
      int i;

      for (i = 0; list[i].name != NULL; i++)
            if (list[i].num == num)
                  return (list[i].name);

      return "Unknown";
}

static struct w9968cf_symbolic_list camlist[] = {
      { W9968CF_MOD_GENERIC, "W996[87]CF JPEG USB Dual Mode Camera" },
      { W9968CF_MOD_CLVBWGP, "Creative Labs Video Blaster WebCam Go Plus" },

      /* Other cameras (having the same descriptors as Generic W996[87]CF) */
      { W9968CF_MOD_ADPVDMA, "Aroma Digi Pen VGA Dual Mode ADG-5000" },
      { W9986CF_MOD_AAU, "AVerMedia AVerTV USB" },
      { W9968CF_MOD_CLVBWG, "Creative Labs Video Blaster WebCam Go" },
      { W9968CF_MOD_LL, "Lebon LDC-035A" },
      { W9968CF_MOD_EEEMC, "Ezonics EZ-802 EZMega Cam" },
      { W9968CF_MOD_OOE, "OmniVision OV8610-EDE" },
      { W9968CF_MOD_ODPVDMPC, "OPCOM Digi Pen VGA Dual Mode Pen Camera" },
      { W9968CF_MOD_PDPII, "Pretec Digi Pen-II" },
      { W9968CF_MOD_PDP480, "Pretec DigiPen-480" },

      {  -1, NULL }
};

static struct w9968cf_symbolic_list senlist[] = {
      { CC_OV76BE,   "OV76BE" },
      { CC_OV7610,   "OV7610" },
      { CC_OV7620,   "OV7620" },
      { CC_OV7620AE, "OV7620AE" },
      { CC_OV6620,   "OV6620" },
      { CC_OV6630,   "OV6630" },
      { CC_OV6630AE, "OV6630AE" },
      { CC_OV6630AF, "OV6630AF" },
      { -1, NULL }
};

/* Video4Linux1 palettes */
static struct w9968cf_symbolic_list v4l1_plist[] = {
      { VIDEO_PALETTE_GREY,    "GREY" },
      { VIDEO_PALETTE_HI240,   "HI240" },
      { VIDEO_PALETTE_RGB565,  "RGB565" },
      { VIDEO_PALETTE_RGB24,   "RGB24" },
      { VIDEO_PALETTE_RGB32,   "RGB32" },
      { VIDEO_PALETTE_RGB555,  "RGB555" },
      { VIDEO_PALETTE_YUV422,  "YUV422" },
      { VIDEO_PALETTE_YUYV,    "YUYV" },
      { VIDEO_PALETTE_UYVY,    "UYVY" },
      { VIDEO_PALETTE_YUV420,  "YUV420" },
      { VIDEO_PALETTE_YUV411,  "YUV411" },
      { VIDEO_PALETTE_RAW,     "RAW" },
      { VIDEO_PALETTE_YUV422P, "YUV422P" },
      { VIDEO_PALETTE_YUV411P, "YUV411P" },
      { VIDEO_PALETTE_YUV420P, "YUV420P" },
      { VIDEO_PALETTE_YUV410P, "YUV410P" },
      { -1, NULL }
};

/* Decoder error codes: */
static struct w9968cf_symbolic_list decoder_errlist[] = {
      { W9968CF_DEC_ERR_CORRUPTED_DATA, "Corrupted data" },
      { W9968CF_DEC_ERR_BUF_OVERFLOW,   "Buffer overflow" },
      { W9968CF_DEC_ERR_NO_SOI,         "SOI marker not found" },
      { W9968CF_DEC_ERR_NO_SOF0,        "SOF0 marker not found" },
      { W9968CF_DEC_ERR_NO_SOS,         "SOS marker not found" },
      { W9968CF_DEC_ERR_NO_EOI,         "EOI marker not found" },
      { -1, NULL }
};

/* URB error codes: */
static struct w9968cf_symbolic_list urb_errlist[] = {
      { -ENOMEM,    "No memory for allocation of internal structures" },
      { -ENOSPC,    "The host controller's bandwidth is already consumed" },
      { -ENOENT,    "URB was canceled by unlink_urb" },
      { -EXDEV,     "ISO transfer only partially completed" },
      { -EAGAIN,    "Too match scheduled for the future" },
      { -ENXIO,     "URB already queued" },
      { -EFBIG,     "Too much ISO frames requested" },
      { -ENOSR,     "Buffer error (overrun)" },
      { -EPIPE,     "Specified endpoint is stalled (device not responding)"},
      { -EOVERFLOW, "Babble (too much data)" },
      { -EPROTO,    "Bit-stuff error (bad cable?)" },
      { -EILSEQ,    "CRC/Timeout" },
      { -ETIME,     "Device does not respond to token" },
      { -ETIMEDOUT, "Device does not respond to command" },
      { -1, NULL }
};

/****************************************************************************
 * Memory management functions                                              *
 ****************************************************************************/
static void* 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 rvfree(void* mem, unsigned long size)
{
      unsigned long adr;

      if (!mem)
            return;

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


/*--------------------------------------------------------------------------
  Deallocate previously allocated memory.
  --------------------------------------------------------------------------*/
static void w9968cf_deallocate_memory(struct w9968cf_device* cam)
{
      u8 i;

      /* Free the isochronous transfer buffers */
      for (i = 0; i < W9968CF_URBS; i++) {
            kfree(cam->transfer_buffer[i]);
            cam->transfer_buffer[i] = NULL;
      }

      /* Free temporary frame buffer */
      if (cam->frame_tmp.buffer) {
            rvfree(cam->frame_tmp.buffer, cam->frame_tmp.size);
            cam->frame_tmp.buffer = NULL;
      }

      /* Free helper buffer */
      if (cam->frame_vpp.buffer) {
            rvfree(cam->frame_vpp.buffer, cam->frame_vpp.size);
            cam->frame_vpp.buffer = NULL;
      }

      /* Free video frame buffers */
      if (cam->frame[0].buffer) {
            rvfree(cam->frame[0].buffer, cam->nbuffers*cam->frame[0].size);
            cam->frame[0].buffer = NULL;
      }

      cam->nbuffers = 0;

      DBG(5, "Memory successfully deallocated")
}


/*--------------------------------------------------------------------------
  Allocate memory buffers for USB transfers and video frames.
  This function is called by open() only.
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_allocate_memory(struct w9968cf_device* cam)
{
      const u16 p_size = wMaxPacketSize[cam->altsetting-1];
      void* buff = NULL;
      unsigned long hw_bufsize, vpp_bufsize;
      u8 i, bpp;

      /* NOTE: Deallocation is done elsewhere in case of error */

      /* Calculate the max amount of raw data per frame from the device */
      hw_bufsize = cam->maxwidth*cam->maxheight*2;

      /* Calculate the max buf. size needed for post-processing routines */
      bpp = (w9968cf_vpp) ? 4 : 2;
      if (cam->upscaling)
            vpp_bufsize = max(W9968CF_MAX_WIDTH*W9968CF_MAX_HEIGHT*bpp,
                          cam->maxwidth*cam->maxheight*bpp);
      else
            vpp_bufsize = cam->maxwidth*cam->maxheight*bpp;

      /* Allocate memory for the isochronous transfer buffers */
      for (i = 0; i < W9968CF_URBS; i++) {
            if (!(cam->transfer_buffer[i] =
                  kzalloc(W9968CF_ISO_PACKETS*p_size, GFP_KERNEL))) {
                  DBG(1, "Couldn't allocate memory for the isochronous "
                         "transfer buffers (%u bytes)",
                      p_size * W9968CF_ISO_PACKETS)
                  return -ENOMEM;
            }
      }

      /* Allocate memory for the temporary frame buffer */
      if (!(cam->frame_tmp.buffer = rvmalloc(hw_bufsize))) {
            DBG(1, "Couldn't allocate memory for the temporary "
                   "video frame buffer (%lu bytes)", hw_bufsize)
            return -ENOMEM;
      }
      cam->frame_tmp.size = hw_bufsize;
      cam->frame_tmp.number = -1;

      /* Allocate memory for the helper buffer */
      if (w9968cf_vpp) {
            if (!(cam->frame_vpp.buffer = rvmalloc(vpp_bufsize))) {
                  DBG(1, "Couldn't allocate memory for the helper buffer"
                         " (%lu bytes)", vpp_bufsize)
                  return -ENOMEM;
            }
            cam->frame_vpp.size = vpp_bufsize;
      } else
            cam->frame_vpp.buffer = NULL;

      /* Allocate memory for video frame buffers */
      cam->nbuffers = cam->max_buffers;
      while (cam->nbuffers >= 2) {
            if ((buff = rvmalloc(cam->nbuffers * vpp_bufsize)))
                  break;
            else
                  cam->nbuffers--;
      }

      if (!buff) {
            DBG(1, "Couldn't allocate memory for the video frame buffers")
            cam->nbuffers = 0;
            return -ENOMEM;
      }

      if (cam->nbuffers != cam->max_buffers)
            DBG(2, "Couldn't allocate memory for %u video frame buffers. "
                   "Only memory for %u buffers has been allocated",
                cam->max_buffers, cam->nbuffers)

      for (i = 0; i < cam->nbuffers; i++) {
            cam->frame[i].buffer = buff + i*vpp_bufsize;
            cam->frame[i].size = vpp_bufsize;
            cam->frame[i].number = i;
            /* Circular list */
            if (i != cam->nbuffers-1)
                  cam->frame[i].next = &cam->frame[i+1];
            else
                  cam->frame[i].next = &cam->frame[0];
            cam->frame[i].status = F_UNUSED;
      }

      DBG(5, "Memory successfully allocated")
      return 0;
}



/****************************************************************************
 * USB-specific functions                                                   *
 ****************************************************************************/

/*--------------------------------------------------------------------------
  This is an handler function which is called after the URBs are completed.
  It collects multiple data packets coming from the camera by putting them
  into frame buffers: one or more zero data length data packets are used to
  mark the end of a video frame; the first non-zero data packet is the start
  of the next video frame; if an error is encountered in a packet, the entire
  video frame is discarded and grabbed again.
  If there are no requested frames in the FIFO list, packets are collected into
  a temporary buffer.
  --------------------------------------------------------------------------*/
static void w9968cf_urb_complete(struct urb *urb)
{
      struct w9968cf_device* cam = (struct w9968cf_device*)urb->context;
      struct w9968cf_frame_t** f;
      unsigned int len, status;
      void* pos;
      u8 i;
      int err = 0;

      if ((!cam->streaming) || cam->disconnected) {
            DBG(4, "Got interrupt, but not streaming")
            return;
      }

      /* "(*f)" will be used instead of "cam->frame_current" */
      f = &cam->frame_current;

      /* If a frame has been requested and we are grabbing into
         the temporary frame, we'll switch to that requested frame */
      if ((*f) == &cam->frame_tmp && *cam->requested_frame) {
            if (cam->frame_tmp.status == F_GRABBING) {
                  w9968cf_pop_frame(cam, &cam->frame_current);
                  (*f)->status = F_GRABBING;
                  (*f)->length = cam->frame_tmp.length;
                  memcpy((*f)->buffer, cam->frame_tmp.buffer,
                         (*f)->length);
                  DBG(6, "Switched from temp. frame to frame #%d",
                      (*f)->number)
            }
      }

      for (i = 0; i < urb->number_of_packets; i++) {
            len = urb->iso_frame_desc[i].actual_length;
            status = urb->iso_frame_desc[i].status;
            pos = urb->iso_frame_desc[i].offset + urb->transfer_buffer;

            if (status && len != 0) {
                  DBG(4, "URB failed, error in data packet "
                         "(error #%u, %s)",
                      status, symbolic(urb_errlist, status))
                  (*f)->status = F_ERROR;
                  continue;
            }

            if (len) { /* start of frame */

                  if ((*f)->status == F_UNUSED) {
                        (*f)->status = F_GRABBING;
                        (*f)->length = 0;
                  }

                  /* Buffer overflows shouldn't happen, however...*/
                  if ((*f)->length + len > (*f)->size) {
                        DBG(4, "Buffer overflow: bad data packets")
                        (*f)->status = F_ERROR;
                  }

                  if ((*f)->status == F_GRABBING) {
                        memcpy((*f)->buffer + (*f)->length, pos, len);
                        (*f)->length += len;
                  }

            } else if ((*f)->status == F_GRABBING) { /* end of frame */

                  DBG(6, "Frame #%d successfully grabbed", (*f)->number)

                  if (cam->vpp_flag & VPP_DECOMPRESSION) {
                        err = w9968cf_vpp->check_headers((*f)->buffer,
                                                 (*f)->length);
                        if (err) {
                              DBG(4, "Skip corrupted frame: %s",
                                  symbolic(decoder_errlist, err))
                              (*f)->status = F_UNUSED;
                              continue; /* grab this frame again */
                        }
                  }

                  (*f)->status = F_READY;
                  (*f)->queued = 0;

                  /* Take a pointer to the new frame from the FIFO list.
                     If the list is empty,we'll use the temporary frame*/
                  if (*cam->requested_frame)
                        w9968cf_pop_frame(cam, &cam->frame_current);
                  else {
                        cam->frame_current = &cam->frame_tmp;
                        (*f)->status = F_UNUSED;
                  }

            } else if ((*f)->status == F_ERROR)
                  (*f)->status = F_UNUSED; /* grab it again */

            PDBGG("Frame length %lu | pack.#%u | pack.len. %u | state %d",
                  (unsigned long)(*f)->length, i, len, (*f)->status)

      } /* end for */

      /* Resubmit this URB */
      urb->dev = cam->usbdev;
      urb->status = 0;
      spin_lock(&cam->urb_lock);
      if (cam->streaming)
            if ((err = usb_submit_urb(urb, GFP_ATOMIC))) {
                  cam->misconfigured = 1;
                  DBG(1, "Couldn't resubmit the URB: error %d, %s",
                      err, symbolic(urb_errlist, err))
            }
      spin_unlock(&cam->urb_lock);

      /* Wake up the user process */
      wake_up_interruptible(&cam->wait_queue);
}


/*---------------------------------------------------------------------------
  Setup the URB structures for the isochronous transfer.
  Submit the URBs so that the data transfer begins.
  Return 0 on success, a negative number otherwise.
  ---------------------------------------------------------------------------*/
static int w9968cf_start_transfer(struct w9968cf_device* cam)
{
      struct usb_device *udev = cam->usbdev;
      struct urb* urb;
      const u16 p_size = wMaxPacketSize[cam->altsetting-1];
      u16 w, h, d;
      int vidcapt;
      u32 t_size;
      int err = 0;
      s8 i, j;

      for (i = 0; i < W9968CF_URBS; i++) {
            urb = usb_alloc_urb(W9968CF_ISO_PACKETS, GFP_KERNEL);
            if (!urb) {
                  for (j = 0; j < i; j++)
                        usb_free_urb(cam->urb[j]);
                  DBG(1, "Couldn't allocate the URB structures")
                  return -ENOMEM;
            }

            cam->urb[i] = urb;
            urb->dev = udev;
            urb->context = (void*)cam;
            urb->pipe = usb_rcvisocpipe(udev, 1);
            urb->transfer_flags = URB_ISO_ASAP;
            urb->number_of_packets = W9968CF_ISO_PACKETS;
            urb->complete = w9968cf_urb_complete;
            urb->transfer_buffer = cam->transfer_buffer[i];
            urb->transfer_buffer_length = p_size*W9968CF_ISO_PACKETS;
            urb->interval = 1;
            for (j = 0; j < W9968CF_ISO_PACKETS; j++) {
                  urb->iso_frame_desc[j].offset = p_size*j;
                  urb->iso_frame_desc[j].length = p_size;
            }
      }

      /* Transfer size per frame, in WORD ! */
      d = cam->hw_depth;
      w = cam->hw_width;
      h = cam->hw_height;

      t_size = (w*h*d)/16;

      err = w9968cf_write_reg(cam, 0xbf17, 0x00); /* reset everything */
      err += w9968cf_write_reg(cam, 0xbf10, 0x00); /* normal operation */

      /* Transfer size */
      err += w9968cf_write_reg(cam, t_size & 0xffff, 0x3d); /* low bits */
      err += w9968cf_write_reg(cam, t_size >> 16, 0x3e);    /* high bits */

      if (cam->vpp_flag & VPP_DECOMPRESSION)
            err += w9968cf_upload_quantizationtables(cam);

      vidcapt = w9968cf_read_reg(cam, 0x16); /* read picture settings */
      err += w9968cf_write_reg(cam, vidcapt|0x8000, 0x16); /* capt. enable */

      err += usb_set_interface(udev, 0, cam->altsetting);
      err += w9968cf_write_reg(cam, 0x8a05, 0x3c); /* USB FIFO enable */

      if (err || (vidcapt < 0)) {
            for (i = 0; i < W9968CF_URBS; i++)
                  usb_free_urb(cam->urb[i]);
            DBG(1, "Couldn't tell the camera to start the data transfer")
            return err;
      }

      w9968cf_init_framelist(cam);

      /* Begin to grab into the temporary buffer */
      cam->frame_tmp.status = F_UNUSED;
      cam->frame_tmp.queued = 0;
      cam->frame_current = &cam->frame_tmp;

      if (!(cam->vpp_flag & VPP_DECOMPRESSION))
            DBG(5, "Isochronous transfer size: %lu bytes/frame",
                (unsigned long)t_size*2)

      DBG(5, "Starting the isochronous transfer...")

      cam->streaming = 1;

      /* Submit the URBs */
      for (i = 0; i < W9968CF_URBS; i++) {
            err = usb_submit_urb(cam->urb[i], GFP_KERNEL);
            if (err) {
                  cam->streaming = 0;
                  for (j = i-1; j >= 0; j--) {
                        usb_kill_urb(cam->urb[j]);
                        usb_free_urb(cam->urb[j]);
                  }
                  DBG(1, "Couldn't send a transfer request to the "
                         "USB core (error #%d, %s)", err,
                      symbolic(urb_errlist, err))
                  return err;
            }
      }

      return 0;
}


/*--------------------------------------------------------------------------
  Stop the isochronous transfer and set alternate setting to 0 (0Mb/s).
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_stop_transfer(struct w9968cf_device* cam)
{
      struct usb_device *udev = cam->usbdev;
      unsigned long lock_flags;
      int err = 0;
      s8 i;

      if (!cam->streaming)
            return 0;

      /* This avoids race conditions with usb_submit_urb()
         in the URB completition handler */
      spin_lock_irqsave(&cam->urb_lock, lock_flags);
      cam->streaming = 0;
      spin_unlock_irqrestore(&cam->urb_lock, lock_flags);

      for (i = W9968CF_URBS-1; i >= 0; i--)
            if (cam->urb[i]) {
                  usb_kill_urb(cam->urb[i]);
                  usb_free_urb(cam->urb[i]);
                  cam->urb[i] = NULL;
            }

      if (cam->disconnected)
            goto exit;

      err = w9968cf_write_reg(cam, 0x0a05, 0x3c); /* stop USB transfer */
      err += usb_set_interface(udev, 0, 0); /* 0 Mb/s */
      err += w9968cf_write_reg(cam, 0x0000, 0x39); /* disable JPEG encoder */
      err += w9968cf_write_reg(cam, 0x0000, 0x16); /* stop video capture */

      if (err) {
            DBG(2, "Failed to tell the camera to stop the isochronous "
                   "transfer. However this is not a critical error.")
            return -EIO;
      }

exit:
      DBG(5, "Isochronous transfer stopped")
      return 0;
}


/*--------------------------------------------------------------------------
  Write a W9968CF register.
  Return 0 on success, -1 otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_write_reg(struct w9968cf_device* cam, u16 value, u16 index)
{
      struct usb_device* udev = cam->usbdev;
      int res;

      res = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0,
                        USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                        value, index, NULL, 0, W9968CF_USB_CTRL_TIMEOUT);

      if (res < 0)
            DBG(4, "Failed to write a register "
                   "(value 0x%04X, index 0x%02X, error #%d, %s)",
                value, index, res, symbolic(urb_errlist, res))

      return (res >= 0) ? 0 : -1;
}


/*--------------------------------------------------------------------------
  Read a W9968CF register.
  Return the register value on success, -1 otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_read_reg(struct w9968cf_device* cam, u16 index)
{
      struct usb_device* udev = cam->usbdev;
      u16* buff = cam->control_buffer;
      int res;

      res = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), 1,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        0, index, buff, 2, W9968CF_USB_CTRL_TIMEOUT);

      if (res < 0)
            DBG(4, "Failed to read a register "
                   "(index 0x%02X, error #%d, %s)",
                index, res, symbolic(urb_errlist, res))

      return (res >= 0) ? (int)(*buff) : -1;
}


/*--------------------------------------------------------------------------
  Write 64-bit data to the fast serial bus registers.
  Return 0 on success, -1 otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_write_fsb(struct w9968cf_device* cam, u16* data)
{
      struct usb_device* udev = cam->usbdev;
      u16 value;
      int res;

      value = *data++;

      res = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0,
                        USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                        value, 0x06, data, 6, W9968CF_USB_CTRL_TIMEOUT);

      if (res < 0)
            DBG(4, "Failed to write the FSB registers "
                   "(error #%d, %s)", res, symbolic(urb_errlist, res))

      return (res >= 0) ? 0 : -1;
}


/*--------------------------------------------------------------------------
  Write data to the serial bus control register.
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_write_sb(struct w9968cf_device* cam, u16 value)
{
      int err = 0;

      err = w9968cf_write_reg(cam, value, 0x01);
      udelay(W9968CF_I2C_BUS_DELAY);

      return err;
}


/*--------------------------------------------------------------------------
  Read data from the serial bus control register.
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_read_sb(struct w9968cf_device* cam)
{
      int v = 0;

      v = w9968cf_read_reg(cam, 0x01);
      udelay(W9968CF_I2C_BUS_DELAY);

      return v;
}


/*--------------------------------------------------------------------------
  Upload quantization tables for the JPEG compression.
  This function is called by w9968cf_start_transfer().
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_upload_quantizationtables(struct w9968cf_device* cam)
{
      u16 a, b;
      int err = 0, i, j;

      err += w9968cf_write_reg(cam, 0x0010, 0x39); /* JPEG clock enable */

      for (i = 0, j = 0; i < 32; i++, j += 2) {
            a = Y_QUANTABLE[j] | ((unsigned)(Y_QUANTABLE[j+1]) << 8);
            b = UV_QUANTABLE[j] | ((unsigned)(UV_QUANTABLE[j+1]) << 8);
            err += w9968cf_write_reg(cam, a, 0x40+i);
            err += w9968cf_write_reg(cam, b, 0x60+i);
      }
      err += w9968cf_write_reg(cam, 0x0012, 0x39); /* JPEG encoder enable */

      return err;
}



/****************************************************************************
 * Low-level I2C I/O functions.                                             *
 * The adapter supports the following I2C transfer functions:               *
 * i2c_adap_fastwrite_byte_data() (at 400 kHz bit frequency only)           *
 * i2c_adap_read_byte_data()                                                *
 * i2c_adap_read_byte()                                                     *
 ****************************************************************************/

static int w9968cf_smbus_start(struct w9968cf_device* cam)
{
      int err = 0;

      err += w9968cf_write_sb(cam, 0x0011); /* SDE=1, SDA=0, SCL=1 */
      err += w9968cf_write_sb(cam, 0x0010); /* SDE=1, SDA=0, SCL=0 */

      return err;
}


static int w9968cf_smbus_stop(struct w9968cf_device* cam)
{
      int err = 0;

      err += w9968cf_write_sb(cam, 0x0011); /* SDE=1, SDA=0, SCL=1 */
      err += w9968cf_write_sb(cam, 0x0013); /* SDE=1, SDA=1, SCL=1 */

      return err;
}


static int w9968cf_smbus_write_byte(struct w9968cf_device* cam, u8 v)
{
      u8 bit;
      int err = 0, sda;

      for (bit = 0 ; bit < 8 ; bit++) {
            sda = (v & 0x80) ? 2 : 0;
            v <<= 1;
            /* SDE=1, SDA=sda, SCL=0 */
            err += w9968cf_write_sb(cam, 0x10 | sda);
            /* SDE=1, SDA=sda, SCL=1 */
            err += w9968cf_write_sb(cam, 0x11 | sda);
            /* SDE=1, SDA=sda, SCL=0 */
            err += w9968cf_write_sb(cam, 0x10 | sda);
      }

      return err;
}


static int w9968cf_smbus_read_byte(struct w9968cf_device* cam, u8* v)
{
      u8 bit;
      int err = 0;

      *v = 0;
      for (bit = 0 ; bit < 8 ; bit++) {
            *v <<= 1;
            err += w9968cf_write_sb(cam, 0x0013);
            *v |= (w9968cf_read_sb(cam) & 0x0008) ? 1 : 0;
            err += w9968cf_write_sb(cam, 0x0012);
      }

      return err;
}


static int w9968cf_smbus_write_ack(struct w9968cf_device* cam)
{
      int err = 0;

      err += w9968cf_write_sb(cam, 0x0010); /* SDE=1, SDA=0, SCL=0 */
      err += w9968cf_write_sb(cam, 0x0011); /* SDE=1, SDA=0, SCL=1 */
      err += w9968cf_write_sb(cam, 0x0010); /* SDE=1, SDA=0, SCL=0 */

      return err;
}


static int w9968cf_smbus_read_ack(struct w9968cf_device* cam)
{
      int err = 0, sda;

      err += w9968cf_write_sb(cam, 0x0013); /* SDE=1, SDA=1, SCL=1 */
      sda = (w9968cf_read_sb(cam) & 0x08) ? 1 : 0; /* sda = SDA */
      err += w9968cf_write_sb(cam, 0x0012); /* SDE=1, SDA=1, SCL=0 */
      if (sda < 0)
            err += sda;
      if (sda == 1) {
            DBG(6, "Couldn't receive the ACK")
            err += -1;
      }

      return err;
}


/* This seems to refresh the communication through the serial bus */
static int w9968cf_smbus_refresh_bus(struct w9968cf_device* cam)
{
      int err = 0, j;

      for (j = 1; j <= 10; j++) {
            err = w9968cf_write_reg(cam, 0x0020, 0x01);
            err += w9968cf_write_reg(cam, 0x0000, 0x01);
            if (err)
                  break;
      }

      return err;
}


/* SMBus protocol: S Addr Wr [A] Subaddr [A] Value [A] P */
static int
w9968cf_i2c_adap_fastwrite_byte_data(struct w9968cf_device* cam,
                             u16 address, u8 subaddress,u8 value)
{
      u16* data = cam->data_buffer;
      int err = 0;

      err += w9968cf_smbus_refresh_bus(cam);

      /* Enable SBUS outputs */
      err += w9968cf_write_sb(cam, 0x0020);

      data[0] = 0x082f | ((address & 0x80) ? 0x1500 : 0x0);
      data[0] |= (address & 0x40) ? 0x4000 : 0x0;
      data[1] = 0x2082 | ((address & 0x40) ? 0x0005 : 0x0);
      data[1] |= (address & 0x20) ? 0x0150 : 0x0;
      data[1] |= (address & 0x10) ? 0x5400 : 0x0;
      data[2] = 0x8208 | ((address & 0x08) ? 0x0015 : 0x0);
      data[2] |= (address & 0x04) ? 0x0540 : 0x0;
      data[2] |= (address & 0x02) ? 0x5000 : 0x0;
      data[3] = 0x1d20 | ((address & 0x02) ? 0x0001 : 0x0);
      data[3] |= (address & 0x01) ? 0x0054 : 0x0;

      err += w9968cf_write_fsb(cam, data);

      data[0] = 0x8208 | ((subaddress & 0x80) ? 0x0015 : 0x0);
      data[0] |= (subaddress & 0x40) ? 0x0540 : 0x0;
      data[0] |= (subaddress & 0x20) ? 0x5000 : 0x0;
      data[1] = 0x0820 | ((subaddress & 0x20) ? 0x0001 : 0x0);
      data[1] |= (subaddress & 0x10) ? 0x0054 : 0x0;
      data[1] |= (subaddress & 0x08) ? 0x1500 : 0x0;
      data[1] |= (subaddress & 0x04) ? 0x4000 : 0x0;
      data[2] = 0x2082 | ((subaddress & 0x04) ? 0x0005 : 0x0);
      data[2] |= (subaddress & 0x02) ? 0x0150 : 0x0;
      data[2] |= (subaddress & 0x01) ? 0x5400 : 0x0;
      data[3] = 0x001d;

      err += w9968cf_write_fsb(cam, data);

      data[0] = 0x8208 | ((value & 0x80) ? 0x0015 : 0x0);
      data[0] |= (value & 0x40) ? 0x0540 : 0x0;
      data[0] |= (value & 0x20) ? 0x5000 : 0x0;
      data[1] = 0x0820 | ((value & 0x20) ? 0x0001 : 0x0);
      data[1] |= (value & 0x10) ? 0x0054 : 0x0;
      data[1] |= (value & 0x08) ? 0x1500 : 0x0;
      data[1] |= (value & 0x04) ? 0x4000 : 0x0;
      data[2] = 0x2082 | ((value & 0x04) ? 0x0005 : 0x0);
      data[2] |= (value & 0x02) ? 0x0150 : 0x0;
      data[2] |= (value & 0x01) ? 0x5400 : 0x0;
      data[3] = 0xfe1d;

      err += w9968cf_write_fsb(cam, data);

      /* Disable SBUS outputs */
      err += w9968cf_write_sb(cam, 0x0000);

      if (!err)
            DBG(5, "I2C write byte data done, addr.0x%04X, subaddr.0x%02X "
                   "value 0x%02X", address, subaddress, value)
      else
            DBG(5, "I2C write byte data failed, addr.0x%04X, "
                   "subaddr.0x%02X, value 0x%02X",
                address, subaddress, value)

      return err;
}


/* SMBus protocol: S Addr Wr [A] Subaddr [A] P S Addr+1 Rd [A] [Value] NA P */
static int
w9968cf_i2c_adap_read_byte_data(struct w9968cf_device* cam,
                        u16 address, u8 subaddress,
                        u8* value)
{
      int err = 0;

      /* Serial data enable */
      err += w9968cf_write_sb(cam, 0x0013); /* don't change ! */

      err += w9968cf_smbus_start(cam);
      err += w9968cf_smbus_write_byte(cam, address);
      err += w9968cf_smbus_read_ack(cam);
      err += w9968cf_smbus_write_byte(cam, subaddress);
      err += w9968cf_smbus_read_ack(cam);
      err += w9968cf_smbus_stop(cam);
      err += w9968cf_smbus_start(cam);
      err += w9968cf_smbus_write_byte(cam, address + 1);
      err += w9968cf_smbus_read_ack(cam);
      err += w9968cf_smbus_read_byte(cam, value);
      err += w9968cf_smbus_write_ack(cam);
      err += w9968cf_smbus_stop(cam);

      /* Serial data disable */
      err += w9968cf_write_sb(cam, 0x0000);

      if (!err)
            DBG(5, "I2C read byte data done, addr.0x%04X, "
                   "subaddr.0x%02X, value 0x%02X",
                address, subaddress, *value)
      else
            DBG(5, "I2C read byte data failed, addr.0x%04X, "
                   "subaddr.0x%02X, wrong value 0x%02X",
                address, subaddress, *value)

      return err;
}


/* SMBus protocol: S Addr+1 Rd [A] [Value] NA P */
static int
w9968cf_i2c_adap_read_byte(struct w9968cf_device* cam,
                     u16 address, u8* value)
{
      int err = 0;

      /* Serial data enable */
      err += w9968cf_write_sb(cam, 0x0013);

      err += w9968cf_smbus_start(cam);
      err += w9968cf_smbus_write_byte(cam, address + 1);
      err += w9968cf_smbus_read_ack(cam);
      err += w9968cf_smbus_read_byte(cam, value);
      err += w9968cf_smbus_write_ack(cam);
      err += w9968cf_smbus_stop(cam);

      /* Serial data disable */
      err += w9968cf_write_sb(cam, 0x0000);

      if (!err)
            DBG(5, "I2C read byte done, addr.0x%04X, "
                   "value 0x%02X", address, *value)
      else
            DBG(5, "I2C read byte failed, addr.0x%04X, "
                   "wrong value 0x%02X", address, *value)

      return err;
}


/* SMBus protocol: S Addr Wr [A] Value [A] P */
static int
w9968cf_i2c_adap_write_byte(struct w9968cf_device* cam,
                      u16 address, u8 value)
{
      DBG(4, "i2c_write_byte() is an unsupported transfer mode")
      return -EINVAL;
}



/****************************************************************************
 * I2C interface to kernel                                                  *
 ****************************************************************************/

static int
w9968cf_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
                   unsigned short flags, char read_write, u8 command,
                   int size, union i2c_smbus_data *data)
{
      struct v4l2_device *v4l2_dev = i2c_get_adapdata(adapter);
      struct w9968cf_device *cam = to_cam(v4l2_dev);
      u8 i;
      int err = 0;

      if (size == I2C_SMBUS_BYTE) {
            /* Why addr <<= 1? See OVXXX0_SID defines in ovcamchip.h */
            addr <<= 1;

            if (read_write == I2C_SMBUS_WRITE)
                  err = w9968cf_i2c_adap_write_byte(cam, addr, command);
            else if (read_write == I2C_SMBUS_READ)
                  for (i = 1; i <= W9968CF_I2C_RW_RETRIES; i++) {
                        err = w9968cf_i2c_adap_read_byte(cam, addr,
                                           &data->byte);
                        if (err) {
                              if (w9968cf_smbus_refresh_bus(cam)) {
                                    err = -EIO;
                                    break;
                              }
                        } else
                              break;
                  }
      } else if (size == I2C_SMBUS_BYTE_DATA) {
            addr <<= 1;

            if (read_write == I2C_SMBUS_WRITE)
                  err = w9968cf_i2c_adap_fastwrite_byte_data(cam, addr,
                                            command, data->byte);
            else if (read_write == I2C_SMBUS_READ) {
                  for (i = 1; i <= W9968CF_I2C_RW_RETRIES; i++) {
                        err = w9968cf_i2c_adap_read_byte_data(cam,addr,
                                           command, &data->byte);
                        if (err) {
                              if (w9968cf_smbus_refresh_bus(cam)) {
                                    err = -EIO;
                                    break;
                              }
                        } else
                              break;
                  }

            } else
                  return -EINVAL;

      } else {
            DBG(4, "Unsupported I2C transfer mode (%d)", size)
            return -EINVAL;
      }
      return err;
}


static u32 w9968cf_i2c_func(struct i2c_adapter* adap)
{
      return I2C_FUNC_SMBUS_READ_BYTE |
             I2C_FUNC_SMBUS_READ_BYTE_DATA  |
             I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
}


static int w9968cf_i2c_init(struct w9968cf_device* cam)
{
      int err = 0;

      static struct i2c_algorithm algo = {
            .smbus_xfer =    w9968cf_i2c_smbus_xfer,
            .functionality = w9968cf_i2c_func,
      };

      static struct i2c_adapter adap = {
            .id =                I2C_HW_SMBUS_W9968CF,
            .owner =             THIS_MODULE,
            .algo =              &algo,
      };

      memcpy(&cam->i2c_adapter, &adap, sizeof(struct i2c_adapter));
      strcpy(cam->i2c_adapter.name, "w9968cf");
      cam->i2c_adapter.dev.parent = &cam->usbdev->dev;
      i2c_set_adapdata(&cam->i2c_adapter, &cam->v4l2_dev);

      DBG(6, "Registering I2C adapter with kernel...")

      err = i2c_add_adapter(&cam->i2c_adapter);
      if (err)
            DBG(1, "Failed to register the I2C adapter")
      else
            DBG(5, "I2C adapter registered")

      return err;
}



/****************************************************************************
 * Helper functions                                                         *
 ****************************************************************************/

/*--------------------------------------------------------------------------
  Turn on the LED on some webcams. A beep should be heard too.
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_turn_on_led(struct w9968cf_device* cam)
{
      int err = 0;

      err += w9968cf_write_reg(cam, 0xff00, 0x00); /* power-down */
      err += w9968cf_write_reg(cam, 0xbf17, 0x00); /* reset everything */
      err += w9968cf_write_reg(cam, 0xbf10, 0x00); /* normal operation */
      err += w9968cf_write_reg(cam, 0x0010, 0x01); /* serial bus, SDS high */
      err += w9968cf_write_reg(cam, 0x0000, 0x01); /* serial bus, SDS low */
      err += w9968cf_write_reg(cam, 0x0010, 0x01); /* ..high 'beep-beep' */

      if (err)
            DBG(2, "Couldn't turn on the LED")

      DBG(5, "LED turned on")

      return err;
}


/*--------------------------------------------------------------------------
  Write some registers for the device initialization.
  This function is called once on open().
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_init_chip(struct w9968cf_device* cam)
{
      unsigned long hw_bufsize = cam->maxwidth*cam->maxheight*2,
                  y0 = 0x0000,
                  u0 = y0 + hw_bufsize/2,
                  v0 = u0 + hw_bufsize/4,
                  y1 = v0 + hw_bufsize/4,
                  u1 = y1 + hw_bufsize/2,
                  v1 = u1 + hw_bufsize/4;
      int err = 0;

      err += w9968cf_write_reg(cam, 0xff00, 0x00); /* power off */
      err += w9968cf_write_reg(cam, 0xbf10, 0x00); /* power on */

      err += w9968cf_write_reg(cam, 0x405d, 0x03); /* DRAM timings */
      err += w9968cf_write_reg(cam, 0x0030, 0x04); /* SDRAM timings */

      err += w9968cf_write_reg(cam, y0 & 0xffff, 0x20); /* Y buf.0, low */
      err += w9968cf_write_reg(cam, y0 >> 16, 0x21);    /* Y buf.0, high */
      err += w9968cf_write_reg(cam, u0 & 0xffff, 0x24); /* U buf.0, low */
      err += w9968cf_write_reg(cam, u0 >> 16, 0x25);    /* U buf.0, high */
      err += w9968cf_write_reg(cam, v0 & 0xffff, 0x28); /* V buf.0, low */
      err += w9968cf_write_reg(cam, v0 >> 16, 0x29);    /* V buf.0, high */

      err += w9968cf_write_reg(cam, y1 & 0xffff, 0x22); /* Y buf.1, low */
      err += w9968cf_write_reg(cam, y1 >> 16, 0x23);    /* Y buf.1, high */
      err += w9968cf_write_reg(cam, u1 & 0xffff, 0x26); /* U buf.1, low */
      err += w9968cf_write_reg(cam, u1 >> 16, 0x27);    /* U buf.1, high */
      err += w9968cf_write_reg(cam, v1 & 0xffff, 0x2a); /* V buf.1, low */
      err += w9968cf_write_reg(cam, v1 >> 16, 0x2b);    /* V buf.1, high */

      err += w9968cf_write_reg(cam, y1 & 0xffff, 0x32); /* JPEG buf 0 low */
      err += w9968cf_write_reg(cam, y1 >> 16, 0x33);    /* JPEG buf 0 high */

      err += w9968cf_write_reg(cam, y1 & 0xffff, 0x34); /* JPEG buf 1 low */
      err += w9968cf_write_reg(cam, y1 >> 16, 0x35);    /* JPEG bug 1 high */

      err += w9968cf_write_reg(cam, 0x0000, 0x36);/* JPEG restart interval */
      err += w9968cf_write_reg(cam, 0x0804, 0x37);/*JPEG VLE FIFO threshold*/
      err += w9968cf_write_reg(cam, 0x0000, 0x38);/* disable hw up-scaling */
      err += w9968cf_write_reg(cam, 0x0000, 0x3f); /* JPEG/MCTL test data */

      err += w9968cf_set_picture(cam, cam->picture); /* this before */
      err += w9968cf_set_window(cam, cam->window);

      if (err)
            DBG(1, "Chip initialization failed")
      else
            DBG(5, "Chip successfully initialized")

      return err;
}


/*--------------------------------------------------------------------------
  Return non-zero if the palette is supported, 0 otherwise.
  --------------------------------------------------------------------------*/
static inline u16 w9968cf_valid_palette(u16 palette)
{
      u8 i = 0;
      while (w9968cf_formatlist[i].palette != 0) {
            if (palette == w9968cf_formatlist[i].palette)
                  return palette;
            i++;
      }
      return 0;
}


/*--------------------------------------------------------------------------
  Return the depth corresponding to the given palette.
  Palette _must_ be supported !
  --------------------------------------------------------------------------*/
static inline u16 w9968cf_valid_depth(u16 palette)
{
      u8 i=0;
      while (w9968cf_formatlist[i].palette != palette)
            i++;

      return w9968cf_formatlist[i].depth;
}


/*--------------------------------------------------------------------------
  Return non-zero if the format requires decompression, 0 otherwise.
  --------------------------------------------------------------------------*/
static inline u8 w9968cf_need_decompression(u16 palette)
{
      u8 i = 0;
      while (w9968cf_formatlist[i].palette != 0) {
            if (palette == w9968cf_formatlist[i].palette)
                  return w9968cf_formatlist[i].compression;
            i++;
      }
      return 0;
}


/*--------------------------------------------------------------------------
  Change the picture settings of the camera.
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int
w9968cf_set_picture(struct w9968cf_device* cam, struct video_picture pict)
{
      u16 fmt, hw_depth, hw_palette, reg_v = 0x0000;
      int err = 0;

      /* Make sure we are using a valid depth */
      pict.depth = w9968cf_valid_depth(pict.palette);

      fmt = pict.palette;

      hw_depth = pict.depth; /* depth used by the winbond chip */
      hw_palette = pict.palette; /* palette used by the winbond chip */

      /* VS & HS polarities */
      reg_v = (cam->vs_polarity << 12) | (cam->hs_polarity << 11);

      switch (fmt)
      {
            case VIDEO_PALETTE_UYVY:
                  reg_v |= 0x0000;
                  cam->vpp_flag = VPP_NONE;
                  break;
            case VIDEO_PALETTE_YUV422P:
                  reg_v |= 0x0002;
                  cam->vpp_flag = VPP_DECOMPRESSION;
                  break;
            case VIDEO_PALETTE_YUV420:
            case VIDEO_PALETTE_YUV420P:
                  reg_v |= 0x0003;
                  cam->vpp_flag = VPP_DECOMPRESSION;
                  break;
            case VIDEO_PALETTE_YUYV:
            case VIDEO_PALETTE_YUV422:
                  reg_v |= 0x0000;
                  cam->vpp_flag = VPP_SWAP_YUV_BYTES;
                  hw_palette = VIDEO_PALETTE_UYVY;
                  break;
            /* Original video is used instead of RGBX palettes.
               Software conversion later. */
            case VIDEO_PALETTE_GREY:
            case VIDEO_PALETTE_RGB555:
            case VIDEO_PALETTE_RGB565:
            case VIDEO_PALETTE_RGB24:
            case VIDEO_PALETTE_RGB32:
                  reg_v |= 0x0000; /* UYVY 16 bit is used */
                  hw_depth = 16;
                  hw_palette = VIDEO_PALETTE_UYVY;
                  cam->vpp_flag = VPP_UYVY_TO_RGBX;
                  break;
      }

      /* NOTE: due to memory issues, it is better to disable the hardware
             double buffering during compression */
      if (cam->double_buffer && !(cam->vpp_flag & VPP_DECOMPRESSION))
            reg_v |= 0x0080;

      if (cam->clamping)
            reg_v |= 0x0020;

      if (cam->filter_type == 1)
            reg_v |= 0x0008;
      else if (cam->filter_type == 2)
            reg_v |= 0x000c;

      if ((err = w9968cf_write_reg(cam, reg_v, 0x16)))
            goto error;

      if ((err = w9968cf_sensor_update_picture(cam, pict)))
            goto error;

      /* If all went well, update the device data structure */
      memcpy(&cam->picture, &pict, sizeof(pict));
      cam->hw_depth = hw_depth;
      cam->hw_palette = hw_palette;

      /* Settings changed, so we clear the frame buffers */
      memset(cam->frame[0].buffer, 0, cam->nbuffers*cam->frame[0].size);

      DBG(4, "Palette is %s, depth is %u bpp",
          symbolic(v4l1_plist, pict.palette), pict.depth)

      return 0;

error:
      DBG(1, "Failed to change picture settings")
      return err;
}


/*--------------------------------------------------------------------------
  Change the capture area size of the camera.
  This function _must_ be called _after_ w9968cf_set_picture().
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int
w9968cf_set_window(struct w9968cf_device* cam, struct video_window win)
{
      u16 x, y, w, h, scx, scy, cw, ch, ax, ay;
      unsigned long fw, fh;
      struct ovcamchip_window s_win;
      int err = 0;

      /* Work around to avoid FP arithmetics */
      #define SC(x) ((x) << 10)
      #define UNSC(x) ((x) >> 10)

      /* Make sure we are using a supported resolution */
      if ((err = w9968cf_adjust_window_size(cam, &win.width, &win.height)))
            goto error;

      /* Scaling factors */
      fw = SC(win.width) / cam->maxwidth;
      fh = SC(win.height) / cam->maxheight;

      /* Set up the width and height values used by the chip */
      if ((win.width > cam->maxwidth) || (win.height > cam->maxheight)) {
            cam->vpp_flag |= VPP_UPSCALE;
            /* Calculate largest w,h mantaining the same w/h ratio */
            w = (fw >= fh) ? cam->maxwidth : SC(win.width)/fh;
            h = (fw >= fh) ? SC(win.height)/fw : cam->maxheight;
            if (w < cam->minwidth) /* just in case */
                  w = cam->minwidth;
            if (h < cam->minheight) /* just in case */
                  h = cam->minheight;
      } else {
            cam->vpp_flag &= ~VPP_UPSCALE;
            w = win.width;
            h = win.height;
      }

      /* x,y offsets of the cropped area */
      scx = cam->start_cropx;
      scy = cam->start_cropy;

      /* Calculate cropped area manteining the right w/h ratio */
      if (cam->largeview && !(cam->vpp_flag & VPP_UPSCALE)) {
            cw = (fw >= fh) ? cam->maxwidth : SC(win.width)/fh;
            ch = (fw >= fh) ? SC(win.height)/fw : cam->maxheight;
      } else {
            cw = w;
            ch = h;
      }

      /* Setup the window of the sensor */
      s_win.format = VIDEO_PALETTE_UYVY;
      s_win.width = cam->maxwidth;
      s_win.height = cam->maxheight;
      s_win.quarter = 0; /* full progressive video */

      /* Center it */
      s_win.x = (s_win.width - cw) / 2;
      s_win.y = (s_win.height - ch) / 2;

      /* Clock divisor */
      if (cam->clockdiv >= 0)
            s_win.clockdiv = cam->clockdiv; /* manual override */
      else
            switch (cam->sensor) {
                  case CC_OV6620:
                        s_win.clockdiv = 0;
                        break;
                  case CC_OV6630:
                        s_win.clockdiv = 0;
                        break;
                  case CC_OV76BE:
                  case CC_OV7610:
                  case CC_OV7620:
                        s_win.clockdiv = 0;
                        break;
                  default:
                        s_win.clockdiv = W9968CF_DEF_CLOCKDIVISOR;
            }

      /* We have to scale win.x and win.y offsets */
      if ( (cam->largeview && !(cam->vpp_flag & VPP_UPSCALE))
           || (cam->vpp_flag & VPP_UPSCALE) ) {
            ax = SC(win.x)/fw;
            ay = SC(win.y)/fh;
      } else {
            ax = win.x;
            ay = win.y;
      }

      if ((ax + cw) > cam->maxwidth)
            ax = cam->maxwidth - cw;

      if ((ay + ch) > cam->maxheight)
            ay = cam->maxheight - ch;

      /* Adjust win.x, win.y */
      if ( (cam->largeview && !(cam->vpp_flag & VPP_UPSCALE))
           || (cam->vpp_flag & VPP_UPSCALE) ) {
            win.x = UNSC(ax*fw);
            win.y = UNSC(ay*fh);
      } else {
            win.x = ax;
            win.y = ay;
      }

      /* Offsets used by the chip */
      x = ax + s_win.x;
      y = ay + s_win.y;

      /* Go ! */
      if ((err = w9968cf_sensor_cmd(cam, OVCAMCHIP_CMD_S_MODE, &s_win)))
            goto error;

      err += w9968cf_write_reg(cam, scx + x, 0x10);
      err += w9968cf_write_reg(cam, scy + y, 0x11);
      err += w9968cf_write_reg(cam, scx + x + cw, 0x12);
      err += w9968cf_write_reg(cam, scy + y + ch, 0x13);
      err += w9968cf_write_reg(cam, w, 0x14);
      err += w9968cf_write_reg(cam, h, 0x15);

      /* JPEG width & height */
      err += w9968cf_write_reg(cam, w, 0x30);
      err += w9968cf_write_reg(cam, h, 0x31);

      /* Y & UV frame buffer strides (in WORD) */
      if (cam->vpp_flag & VPP_DECOMPRESSION) {
            err += w9968cf_write_reg(cam, w/2, 0x2c);
            err += w9968cf_write_reg(cam, w/4, 0x2d);
      } else
            err += w9968cf_write_reg(cam, w, 0x2c);

      if (err)
            goto error;

      /* If all went well, update the device data structure */
      memcpy(&cam->window, &win, sizeof(win));
      cam->hw_width = w;
      cam->hw_height = h;

      /* Settings changed, so we clear the frame buffers */
      memset(cam->frame[0].buffer, 0, cam->nbuffers*cam->frame[0].size);

      DBG(4, "The capture area is %dx%d, Offset (x,y)=(%u,%u)",
          win.width, win.height, win.x, win.y)

      PDBGG("x=%u ,y=%u, w=%u, h=%u, ax=%u, ay=%u, s_win.x=%u, s_win.y=%u, "
            "cw=%u, ch=%u, win.x=%u, win.y=%u, win.width=%u, win.height=%u",
            x, y, w, h, ax, ay, s_win.x, s_win.y, cw, ch, win.x, win.y,
            win.width, win.height)

      return 0;

error:
      DBG(1, "Failed to change the capture area size")
      return err;
}


/*--------------------------------------------------------------------------
  Adjust the asked values for window width and height.
  Return 0 on success, -1 otherwise.
  --------------------------------------------------------------------------*/
static int
w9968cf_adjust_window_size(struct w9968cf_device *cam, u32 *width, u32 *height)
{
      unsigned int maxw, maxh, align;

      maxw = cam->upscaling && !(cam->vpp_flag & VPP_DECOMPRESSION) &&
             w9968cf_vpp ? max((u16)W9968CF_MAX_WIDTH, cam->maxwidth)
                     : cam->maxwidth;
      maxh = cam->upscaling && !(cam->vpp_flag & VPP_DECOMPRESSION) &&
             w9968cf_vpp ? max((u16)W9968CF_MAX_HEIGHT, cam->maxheight)
                     : cam->maxheight;
      align = (cam->vpp_flag & VPP_DECOMPRESSION) ? 4 : 0;

      v4l_bound_align_image(width, cam->minwidth, maxw, align,
                        height, cam->minheight, maxh, align, 0);

      PDBGG("Window size adjusted w=%u, h=%u ", *width, *height)

      return 0;
}


/*--------------------------------------------------------------------------
  Initialize the FIFO list of requested frames.
  --------------------------------------------------------------------------*/
static void w9968cf_init_framelist(struct w9968cf_device* cam)
{
      u8 i;

      for (i = 0; i < cam->nbuffers; i++) {
            cam->requested_frame[i] = NULL;
            cam->frame[i].queued = 0;
            cam->frame[i].status = F_UNUSED;
      }
}


/*--------------------------------------------------------------------------
  Add a frame in the FIFO list of requested frames.
  This function is called in process context.
  --------------------------------------------------------------------------*/
static void w9968cf_push_frame(struct w9968cf_device* cam, u8 f_num)
{
      u8 f;
      unsigned long lock_flags;

      spin_lock_irqsave(&cam->flist_lock, lock_flags);

      for (f=0; cam->requested_frame[f] != NULL; f++);
      cam->requested_frame[f] = &cam->frame[f_num];
      cam->frame[f_num].queued = 1;
      cam->frame[f_num].status = F_UNUSED; /* clear the status */

      spin_unlock_irqrestore(&cam->flist_lock, lock_flags);

      DBG(6, "Frame #%u pushed into the FIFO list. Position %u", f_num, f)
}


/*--------------------------------------------------------------------------
  Read, store and remove the first pointer in the FIFO list of requested
  frames. This function is called in interrupt context.
  --------------------------------------------------------------------------*/
static void
w9968cf_pop_frame(struct w9968cf_device* cam, struct w9968cf_frame_t** framep)
{
      u8 i;

      spin_lock(&cam->flist_lock);

      *framep = cam->requested_frame[0];

      /* Shift the list of pointers */
      for (i = 0; i < cam->nbuffers-1; i++)
            cam->requested_frame[i] = cam->requested_frame[i+1];
      cam->requested_frame[i] = NULL;

      spin_unlock(&cam->flist_lock);

      DBG(6,"Popped frame #%d from the list", (*framep)->number)
}


/*--------------------------------------------------------------------------
  High-level video post-processing routine on grabbed frames.
  Return 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int
w9968cf_postprocess_frame(struct w9968cf_device* cam,
                    struct w9968cf_frame_t* fr)
{
      void *pIn = fr->buffer, *pOut = cam->frame_vpp.buffer, *tmp;
      u16 w = cam->window.width,
          h = cam->window.height,
          d = cam->picture.depth,
          fmt = cam->picture.palette,
          rgb = cam->force_rgb,
          hw_w = cam->hw_width,
          hw_h = cam->hw_height,
          hw_d = cam->hw_depth;
      int err = 0;

      #define _PSWAP(pIn, pOut) {tmp = (pIn); (pIn) = (pOut); (pOut) = tmp;}

      if (cam->vpp_flag & VPP_DECOMPRESSION) {
            memcpy(pOut, pIn, fr->length);
            _PSWAP(pIn, pOut)
            err = w9968cf_vpp->decode(pIn, fr->length, hw_w, hw_h, pOut);
            PDBGG("Compressed frame length: %lu",(unsigned long)fr->length)
            fr->length = (hw_w*hw_h*hw_d)/8;
            _PSWAP(pIn, pOut)
            if (err) {
                  DBG(4, "An error occurred while decoding the frame: "
                         "%s", symbolic(decoder_errlist, err))
                  return err;
            } else
                  DBG(6, "Frame decoded")
      }

      if (cam->vpp_flag & VPP_SWAP_YUV_BYTES) {
            w9968cf_vpp->swap_yuvbytes(pIn, fr->length);
            DBG(6, "Original UYVY component ordering changed")
      }

      if (cam->vpp_flag & VPP_UPSCALE) {
            w9968cf_vpp->scale_up(pIn, pOut, hw_w, hw_h, hw_d, w, h);
            fr->length = (w*h*hw_d)/8;
            _PSWAP(pIn, pOut)
            DBG(6, "Vertical up-scaling done: %u,%u,%ubpp->%u,%u",
                hw_w, hw_h, hw_d, w, h)
      }

      if (cam->vpp_flag & VPP_UYVY_TO_RGBX) {
            w9968cf_vpp->uyvy_to_rgbx(pIn, fr->length, pOut, fmt, rgb);
            fr->length = (w*h*d)/8;
            _PSWAP(pIn, pOut)
            DBG(6, "UYVY-16bit to %s conversion done",
                symbolic(v4l1_plist, fmt))
      }

      if (pOut == fr->buffer)
            memcpy(fr->buffer, cam->frame_vpp.buffer, fr->length);

      return 0;
}



/****************************************************************************
 * Image sensor control routines                                            *
 ****************************************************************************/

static int
w9968cf_sensor_set_control(struct w9968cf_device* cam, int cid, int val)
{
      struct ovcamchip_control ctl;
      int err;

      ctl.id = cid;
      ctl.value = val;

      err = w9968cf_sensor_cmd(cam, OVCAMCHIP_CMD_S_CTRL, &ctl);

      return err;
}


static int
w9968cf_sensor_get_control(struct w9968cf_device* cam, int cid, int* val)
{
      struct ovcamchip_control ctl;
      int err;

      ctl.id = cid;

      err = w9968cf_sensor_cmd(cam, OVCAMCHIP_CMD_G_CTRL, &ctl);
      if (!err)
            *val = ctl.value;

      return err;
}


static int
w9968cf_sensor_cmd(struct w9968cf_device* cam, unsigned int cmd, void* arg)
{
      int rc;

      rc = v4l2_subdev_call(cam->sensor_sd, core, ioctl, cmd, arg);
      /* The I2C driver returns -EPERM on non-supported controls */
      return (rc < 0 && rc != -EPERM) ? rc : 0;
}


/*--------------------------------------------------------------------------
  Update some settings of the image sensor.
  Returns: 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_sensor_update_settings(struct w9968cf_device* cam)
{
      int err = 0;

      /* Auto brightness */
      err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_AUTOBRIGHT,
                               cam->auto_brt);
      if (err)
            return err;

      /* Auto exposure */
      err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_AUTOEXP,
                               cam->auto_exp);
      if (err)
            return err;

      /* Banding filter */
      err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_BANDFILT,
                               cam->bandfilt);
      if (err)
            return err;

      /* Light frequency */
      err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_FREQ,
                               cam->lightfreq);
      if (err)
            return err;

      /* Back light */
      err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_BACKLIGHT,
                               cam->backlight);
      if (err)
            return err;

      /* Mirror */
      err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_MIRROR,
                               cam->mirror);
      if (err)
            return err;

      return 0;
}


/*--------------------------------------------------------------------------
  Get some current picture settings from the image sensor and update the
  internal 'picture' structure of the camera.
  Returns: 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_sensor_get_picture(struct w9968cf_device* cam)
{
      int err, v;

      err = w9968cf_sensor_get_control(cam, OVCAMCHIP_CID_CONT, &v);
      if (err)
            return err;
      cam->picture.contrast = v;

      err = w9968cf_sensor_get_control(cam, OVCAMCHIP_CID_BRIGHT, &v);
      if (err)
            return err;
      cam->picture.brightness = v;

      err = w9968cf_sensor_get_control(cam, OVCAMCHIP_CID_SAT, &v);
      if (err)
            return err;
      cam->picture.colour = v;

      err = w9968cf_sensor_get_control(cam, OVCAMCHIP_CID_HUE, &v);
      if (err)
            return err;
      cam->picture.hue = v;

      DBG(5, "Got picture settings from the image sensor")

      PDBGG("Brightness, contrast, hue, colour, whiteness are "
            "%u,%u,%u,%u,%u", cam->picture.brightness,cam->picture.contrast,
            cam->picture.hue, cam->picture.colour, cam->picture.whiteness)

      return 0;
}


/*--------------------------------------------------------------------------
  Update picture settings of the image sensor.
  Returns: 0 on success, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int
w9968cf_sensor_update_picture(struct w9968cf_device* cam,
                        struct video_picture pict)
{
      int err = 0;

      if ((!cam->sensor_initialized)
          || pict.contrast != cam->picture.contrast) {
            err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_CONT,
                                     pict.contrast);
            if (err)
                  goto fail;
            DBG(4, "Contrast changed from %u to %u",
                cam->picture.contrast, pict.contrast)
            cam->picture.contrast = pict.contrast;
      }

      if (((!cam->sensor_initialized) ||
          pict.brightness != cam->picture.brightness) && (!cam->auto_brt)) {
            err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_BRIGHT,
                                     pict.brightness);
            if (err)
                  goto fail;
            DBG(4, "Brightness changed from %u to %u",
                cam->picture.brightness, pict.brightness)
            cam->picture.brightness = pict.brightness;
      }

      if ((!cam->sensor_initialized) || pict.colour != cam->picture.colour) {
            err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_SAT,
                                     pict.colour);
            if (err)
                  goto fail;
            DBG(4, "Colour changed from %u to %u",
                cam->picture.colour, pict.colour)
            cam->picture.colour = pict.colour;
      }

      if ((!cam->sensor_initialized) || pict.hue != cam->picture.hue) {
            err = w9968cf_sensor_set_control(cam, OVCAMCHIP_CID_HUE,
                                     pict.hue);
            if (err)
                  goto fail;
            DBG(4, "Hue changed from %u to %u",
                cam->picture.hue, pict.hue)
            cam->picture.hue = pict.hue;
      }

      return 0;

fail:
      DBG(4, "Failed to change sensor picture setting")
      return err;
}



/****************************************************************************
 * Camera configuration                                                     *
 ****************************************************************************/

/*--------------------------------------------------------------------------
  This function is called when a supported image sensor is detected.
  Return 0 if the initialization succeeds, a negative number otherwise.
  --------------------------------------------------------------------------*/
static int w9968cf_sensor_init(struct w9968cf_device* cam)
{
      int err = 0;

      if ((err = w9968cf_sensor_cmd(cam, OVCAMCHIP_CMD_INITIALIZE,
                              &cam->monochrome)))
            goto error;

      if ((err = w9968cf_sensor_cmd(cam, OVCAMCHIP_CMD_Q_SUBTYPE,
                              &cam->sensor)))
            goto error;

      /* NOTE: Make sure width and height are a multiple of 16 */
      switch (v4l2_i2c_subdev_addr(cam->sensor_sd)) {
            case OV6xx0_SID:
                  cam->maxwidth = 352;
                  cam->maxheight = 288;
                  cam->minwidth = 64;
                  cam->minheight = 48;
                  break;
            case OV7xx0_SID:
                  cam->maxwidth = 640;
                  cam->maxheight = 480;
                  cam->minwidth = 64;
                  cam->minheight = 48;
                  break;
            default:
                  DBG(1, "Not supported image sensor detected for %s",
                      symbolic(camlist, cam->id))
                  return -EINVAL;
      }

      /* These values depend on the ones in the ovxxx0.c sources */
      switch (cam->sensor) {
            case CC_OV7620:
                  cam->start_cropx = 287;
                  cam->start_cropy = 35;
                  /* Seems to work around a bug in the image sensor */
                  cam->vs_polarity = 1;
                  cam->hs_polarity = 1;
                  break;
            default:
                  cam->start_cropx = 320;
                  cam->start_cropy = 35;
                  cam->vs_polarity = 1;
                  cam->hs_polarity = 0;
      }

      if ((err = w9968cf_sensor_update_settings(cam)))
            goto error;

      if ((err = w9968cf_sensor_update_picture(cam, cam->picture)))
            goto error;

      cam->sensor_initialized = 1;

      DBG(2, "%s image sensor initialized", symbolic(senlist, cam->sensor))
      return 0;

error:
      cam->sensor_initialized = 0;
      cam->sensor = CC_UNKNOWN;
      DBG(1, "Image sensor initialization failed for %s (/dev/video%d). "
             "Try to detach and attach this device again",
          symbolic(camlist, cam->id), cam->v4ldev->num)
      return err;
}


/*--------------------------------------------------------------------------
  Fill some basic fields in the main device data structure.
  This function is called once on w9968cf_usb_probe() for each recognized
  camera.
  --------------------------------------------------------------------------*/
static void
w9968cf_configure_camera(struct w9968cf_device* cam,
                   struct usb_device* udev,
                   enum w9968cf_model_id mod_id,
                   const unsigned short dev_nr)
{
      mutex_init(&cam->fileop_mutex);
      init_waitqueue_head(&cam->open);
      spin_lock_init(&cam->urb_lock);
      spin_lock_init(&cam->flist_lock);

      cam->users = 0;
      cam->disconnected = 0;
      cam->id = mod_id;
      cam->sensor = CC_UNKNOWN;
      cam->sensor_initialized = 0;

      /* Calculate the alternate setting number (from 1 to 16)
         according to the 'packet_size' module parameter */
      if (packet_size[dev_nr] < W9968CF_MIN_PACKET_SIZE)
            packet_size[dev_nr] = W9968CF_MIN_PACKET_SIZE;
      for (cam->altsetting = 1;
           packet_size[dev_nr] < wMaxPacketSize[cam->altsetting-1];
           cam->altsetting++);

      cam->max_buffers = (max_buffers[dev_nr] < 2 ||
                      max_buffers[dev_nr] > W9968CF_MAX_BUFFERS)
                     ? W9968CF_BUFFERS : (u8)max_buffers[dev_nr];

      cam->double_buffer = (double_buffer[dev_nr] == 0 ||
                        double_buffer[dev_nr] == 1)
                       ? (u8)double_buffer[dev_nr]:W9968CF_DOUBLE_BUFFER;

      cam->clamping = (clamping[dev_nr] == 0 || clamping[dev_nr] == 1)
                  ? (u8)clamping[dev_nr] : W9968CF_CLAMPING;

      cam->filter_type = (filter_type[dev_nr] == 0 ||
                      filter_type[dev_nr] == 1 ||
                      filter_type[dev_nr] == 2)
                     ? (u8)filter_type[dev_nr] : W9968CF_FILTER_TYPE;

      cam->capture = 1;

      cam->largeview = (largeview[dev_nr] == 0 || largeview[dev_nr] == 1)
                   ? (u8)largeview[dev_nr] : W9968CF_LARGEVIEW;

      cam->decompression = (decompression[dev_nr] == 0 ||
                        decompression[dev_nr] == 1 ||
                        decompression[dev_nr] == 2)
                       ? (u8)decompression[dev_nr]:W9968CF_DECOMPRESSION;

      cam->upscaling = (upscaling[dev_nr] == 0 ||
                    upscaling[dev_nr] == 1)
                   ? (u8)upscaling[dev_nr] : W9968CF_UPSCALING;

      cam->auto_brt = (autobright[dev_nr] == 0 || autobright[dev_nr] == 1)
                  ? (u8)autobright[dev_nr] : W9968CF_AUTOBRIGHT;

      cam->auto_exp = (autoexp[dev_nr] == 0 || autoexp[dev_nr] == 1)
                  ? (u8)autoexp[dev_nr] : W9968CF_AUTOEXP;

      cam->lightfreq = (lightfreq[dev_nr] == 50 || lightfreq[dev_nr] == 60)
                   ? (u8)lightfreq[dev_nr] : W9968CF_LIGHTFREQ;

      cam->bandfilt = (bandingfilter[dev_nr] == 0 ||
                   bandingfilter[dev_nr] == 1)
                  ? (u8)bandingfilter[dev_nr] : W9968CF_BANDINGFILTER;

      cam->backlight = (backlight[dev_nr] == 0 || backlight[dev_nr] == 1)
                   ? (u8)backlight[dev_nr] : W9968CF_BACKLIGHT;

      cam->clockdiv = (clockdiv[dev_nr] == -1 || clockdiv[dev_nr] >= 0)
                  ? (s8)clockdiv[dev_nr] : W9968CF_CLOCKDIV;

      cam->mirror = (mirror[dev_nr] == 0 || mirror[dev_nr] == 1)
                  ? (u8)mirror[dev_nr] : W9968CF_MIRROR;

      cam->monochrome = (monochrome[dev_nr] == 0 || monochrome[dev_nr] == 1)
                    ? monochrome[dev_nr] : W9968CF_MONOCHROME;

      cam->picture.brightness = (u16)brightness[dev_nr];
      cam->picture.hue = (u16)hue[dev_nr];
      cam->picture.colour = (u16)colour[dev_nr];
      cam->picture.contrast = (u16)contrast[dev_nr];
      cam->picture.whiteness = (u16)whiteness[dev_nr];
      if (w9968cf_valid_palette((u16)force_palette[dev_nr])) {
            cam->picture.palette = (u16)force_palette[dev_nr];
            cam->force_palette = 1;
      } else {
            cam->force_palette = 0;
            if (cam->decompression == 0)
                  cam->picture.palette = W9968CF_PALETTE_DECOMP_OFF;
            else if (cam->decompression == 1)
                  cam->picture.palette = W9968CF_PALETTE_DECOMP_FORCE;
            else
                  cam->picture.palette = W9968CF_PALETTE_DECOMP_ON;
      }
      cam->picture.depth = w9968cf_valid_depth(cam->picture.palette);

      cam->force_rgb = (force_rgb[dev_nr] == 0 || force_rgb[dev_nr] == 1)
                   ? (u8)force_rgb[dev_nr] : W9968CF_FORCE_RGB;

      cam->window.x = 0;
      cam->window.y = 0;
      cam->window.width = W9968CF_WIDTH;
      cam->window.height = W9968CF_HEIGHT;
      cam->window.chromakey = 0;
      cam->window.clipcount = 0;
      cam->window.flags = 0;

      DBG(3, "%s configured with settings #%u:",
          symbolic(camlist, cam->id), dev_nr)

      DBG(3, "- Data packet size for USB isochrnous transfer: %u bytes",
          wMaxPacketSize[cam->altsetting-1])

      DBG(3, "- Number of requested video frame buffers: %u",
          cam->max_buffers)

      if (cam->double_buffer)
            DBG(3, "- Hardware double buffering enabled")
      else
            DBG(3, "- Hardware double buffering disabled")

      if (cam->filter_type == 0)
            DBG(3, "- Video filtering disabled")
      else if (cam->filter_type == 1)
            DBG(3, "- Video filtering enabled: type 1-2-1")
      else if (cam->filter_type == 2)
            DBG(3, "- Video filtering enabled: type 2-3-6-3-2")

      if (cam->clamping)
            DBG(3, "- Video data clamping (CCIR-601 format) enabled")
      else
            DBG(3, "- Video data clamping (CCIR-601 format) disabled")

      if (cam->largeview)
            DBG(3, "- Large view enabled")
      else
            DBG(3, "- Large view disabled")

      if ((cam->decompression) == 0 && (!cam->force_palette))
            DBG(3, "- Decompression disabled")
      else if ((cam->decompression) == 1 && (!cam->force_palette))
            DBG(3, "- Decompression forced")
      else if ((cam->decompression) == 2 && (!cam->force_palette))
            DBG(3, "- Decompression allowed")

      if (cam->upscaling)
            DBG(3, "- Software image scaling enabled")
      else
            DBG(3, "- Software image scaling disabled")

      if (cam->force_palette)
            DBG(3, "- Image palette forced to %s",
                symbolic(v4l1_plist, cam->picture.palette))

      if (cam->force_rgb)
            DBG(3, "- RGB component ordering will be used instead of BGR")

      if (cam->auto_brt)
            DBG(3, "- Auto brightness enabled")
      else
            DBG(3, "- Auto brightness disabled")

      if (cam->auto_exp)
            DBG(3, "- Auto exposure enabled")
      else
            DBG(3, "- Auto exposure disabled")

      if (cam->backlight)
            DBG(3, "- Backlight exposure algorithm enabled")
      else
            DBG(3, "- Backlight exposure algorithm disabled")

      if (cam->mirror)
            DBG(3, "- Mirror enabled")
      else
            DBG(3, "- Mirror disabled")

      if (cam->bandfilt)
            DBG(3, "- Banding filter enabled")
      else
            DBG(3, "- Banding filter disabled")

      DBG(3, "- Power lighting frequency: %u", cam->lightfreq)

      if (cam->clockdiv == -1)
            DBG(3, "- Automatic clock divisor enabled")
      else
            DBG(3, "- Clock divisor: %d", cam->clockdiv)

      if (cam->monochrome)
            DBG(3, "- Image sensor used as monochrome")
      else
            DBG(3, "- Image sensor not used as monochrome")
}


/*--------------------------------------------------------------------------
  If the video post-processing module is not loaded, some parameters
  must be overridden.
  --------------------------------------------------------------------------*/
static void w9968cf_adjust_configuration(struct w9968cf_device* cam)
{
      if (!w9968cf_vpp) {
            if (cam->decompression == 1) {
                  cam->decompression = 2;
                  DBG(2, "Video post-processing module not found: "
                         "'decompression' parameter forced to 2")
            }
            if (cam->upscaling) {
                  cam->upscaling = 0;
                  DBG(2, "Video post-processing module not found: "
                         "'upscaling' parameter forced to 0")
            }
            if (cam->picture.palette != VIDEO_PALETTE_UYVY) {
                  cam->force_palette = 0;
                  DBG(2, "Video post-processing module not found: "
                         "'force_palette' parameter forced to 0")
            }
            cam->picture.palette = VIDEO_PALETTE_UYVY;
            cam->picture.depth = w9968cf_valid_depth(cam->picture.palette);
      }
}


/*--------------------------------------------------------------------------
  Release the resources used by the driver.
  This function is called on disconnect
  (or on close if deallocation has been deferred)
  --------------------------------------------------------------------------*/
static void w9968cf_release_resources(struct w9968cf_device* cam)
{
      mutex_lock(&w9968cf_devlist_mutex);

      DBG(2, "V4L device deregistered: /dev/video%d", cam->v4ldev->num)

      video_unregister_device(cam->v4ldev);
      list_del(&cam->v4llist);
      i2c_del_adapter(&cam->i2c_adapter);
      w9968cf_deallocate_memory(cam);
      kfree(cam->control_buffer);
      kfree(cam->data_buffer);
      v4l2_device_unregister(&cam->v4l2_dev);

      mutex_unlock(&w9968cf_devlist_mutex);
}



/****************************************************************************
 * Video4Linux interface                                                    *
 ****************************************************************************/

static int w9968cf_open(struct file *filp)
{
      struct w9968cf_device* cam;
      int err;

      /* This the only safe way to prevent race conditions with disconnect */
      if (!down_read_trylock(&w9968cf_disconnect))
            return -EAGAIN;

      cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));

      mutex_lock(&cam->dev_mutex);

      if (cam->sensor == CC_UNKNOWN) {
            DBG(2, "No supported image sensor has been detected by the "
                   "'ovcamchip' module for the %s (/dev/video%d). Make "
                   "sure it is loaded *before* (re)connecting the camera.",
                symbolic(camlist, cam->id), cam->v4ldev->num)
            mutex_unlock(&cam->dev_mutex);
            up_read(&w9968cf_disconnect);
            return -ENODEV;
      }

      if (cam->users) {
            DBG(2, "%s (/dev/video%d) has been already occupied by '%s'",
                symbolic(camlist, cam->id), cam->v4ldev->num, cam->command)
            if ((filp->f_flags & O_NONBLOCK)||(filp->f_flags & O_NDELAY)) {
                  mutex_unlock(&cam->dev_mutex);
                  up_read(&w9968cf_disconnect);
                  return -EWOULDBLOCK;
            }
            mutex_unlock(&cam->dev_mutex);
            err = wait_event_interruptible_exclusive(cam->open,
                                           cam->disconnected ||
                                           !cam->users);
            if (err) {
                  up_read(&w9968cf_disconnect);
                  return err;
            }
            if (cam->disconnected) {
                  up_read(&w9968cf_disconnect);
                  return -ENODEV;
            }
            mutex_lock(&cam->dev_mutex);
      }

      DBG(5, "Opening '%s', /dev/video%d ...",
          symbolic(camlist, cam->id), cam->v4ldev->num)

      cam->streaming = 0;
      cam->misconfigured = 0;

      w9968cf_adjust_configuration(cam);

      if ((err = w9968cf_allocate_memory(cam)))
            goto deallocate_memory;

      if ((err = w9968cf_init_chip(cam)))
            goto deallocate_memory;

      if ((err = w9968cf_start_transfer(cam)))
            goto deallocate_memory;

      filp->private_data = cam;

      cam->users++;
      strcpy(cam->command, current->comm);

      init_waitqueue_head(&cam->wait_queue);

      DBG(5, "Video device is open")

      mutex_unlock(&cam->dev_mutex);
      up_read(&w9968cf_disconnect);

      return 0;

deallocate_memory:
      w9968cf_deallocate_memory(cam);
      DBG(2, "Failed to open the video device")
      mutex_unlock(&cam->dev_mutex);
      up_read(&w9968cf_disconnect);
      return err;
}


static int w9968cf_release(struct file *filp)
{
      struct w9968cf_device* cam;

      cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));

      mutex_lock(&cam->dev_mutex); /* prevent disconnect() to be called */

      w9968cf_stop_transfer(cam);

      if (cam->disconnected) {
            w9968cf_release_resources(cam);
            mutex_unlock(&cam->dev_mutex);
            kfree(cam);
            return 0;
      }

      cam->users--;
      w9968cf_deallocate_memory(cam);
      wake_up_interruptible_nr(&cam->open, 1);

      DBG(5, "Video device closed")
      mutex_unlock(&cam->dev_mutex);
      return 0;
}


static ssize_t
w9968cf_read(struct file* filp, char __user * buf, size_t count, loff_t* f_pos)
{
      struct w9968cf_device* cam;
      struct w9968cf_frame_t* fr;
      int err = 0;

      cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));

      if (filp->f_flags & O_NONBLOCK)
            return -EWOULDBLOCK;

      if (mutex_lock_interruptible(&cam->fileop_mutex))
            return -ERESTARTSYS;

      if (cam->disconnected) {
            DBG(2, "Device not present")
            mutex_unlock(&cam->fileop_mutex);
            return -ENODEV;
      }

      if (cam->misconfigured) {
            DBG(2, "The camera is misconfigured. Close and open it again.")
            mutex_unlock(&cam->fileop_mutex);
            return -EIO;
      }

      if (!cam->frame[0].queued)
            w9968cf_push_frame(cam, 0);

      if (!cam->frame[1].queued)
            w9968cf_push_frame(cam, 1);

      err = wait_event_interruptible(cam->wait_queue,
                               cam->frame[0].status == F_READY ||
                               cam->frame[1].status == F_READY ||
                               cam->disconnected);
      if (err) {
            mutex_unlock(&cam->fileop_mutex);
            return err;
      }
      if (cam->disconnected) {
            mutex_unlock(&cam->fileop_mutex);
            return -ENODEV;
      }

      fr = (cam->frame[0].status == F_READY) ? &cam->frame[0]:&cam->frame[1];

      if (w9968cf_vpp)
            w9968cf_postprocess_frame(cam, fr);

      if (count > fr->length)
            count = fr->length;

      if (copy_to_user(buf, fr->buffer, count)) {
            fr->status = F_UNUSED;
            mutex_unlock(&cam->fileop_mutex);
            return -EFAULT;
      }
      *f_pos += count;

      fr->status = F_UNUSED;

      DBG(5, "%zu bytes read", count)

      mutex_unlock(&cam->fileop_mutex);
      return count;
}


static int w9968cf_mmap(struct file* filp, struct vm_area_struct *vma)
{
      struct w9968cf_device* cam = (struct w9968cf_device*)
                             video_get_drvdata(video_devdata(filp));
      unsigned long vsize = vma->vm_end - vma->vm_start,
                  psize = cam->nbuffers * cam->frame[0].size,
                  start = vma->vm_start,
                  pos = (unsigned long)cam->frame[0].buffer,
                  page;

      if (cam->disconnected) {
            DBG(2, "Device not present")
            return -ENODEV;
      }

      if (cam->misconfigured) {
            DBG(2, "The camera is misconfigured. Close and open it again")
            return -EIO;
      }

      PDBGG("mmapping %lu bytes...", vsize)

      if (vsize > psize - (vma->vm_pgoff << PAGE_SHIFT))
            return -EINVAL;

      while (vsize > 0) {
            page = vmalloc_to_pfn((void *)pos);
            if (remap_pfn_range(vma, start, page + vma->vm_pgoff,
                                    PAGE_SIZE, vma->vm_page_prot))
                  return -EAGAIN;
            start += PAGE_SIZE;
            pos += PAGE_SIZE;
            vsize -= PAGE_SIZE;
      }

      DBG(5, "mmap method successfully called")
      return 0;
}


static long
w9968cf_ioctl(struct file *filp,
            unsigned int cmd, unsigned long arg)
{
      struct w9968cf_device* cam;
      long err;

      cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));

      if (mutex_lock_interruptible(&cam->fileop_mutex))
            return -ERESTARTSYS;

      if (cam->disconnected) {
            DBG(2, "Device not present")
            mutex_unlock(&cam->fileop_mutex);
            return -ENODEV;
      }

      if (cam->misconfigured) {
            DBG(2, "The camera is misconfigured. Close and open it again.")
            mutex_unlock(&cam->fileop_mutex);
            return -EIO;
      }

      err = w9968cf_v4l_ioctl(filp, cmd, (void __user *)arg);

      mutex_unlock(&cam->fileop_mutex);
      return err;
}


static long w9968cf_v4l_ioctl(struct file *filp,
                       unsigned int cmd, void __user *arg)
{
      struct w9968cf_device* cam;
      const char* v4l1_ioctls[] = {
            "?", "CGAP", "GCHAN", "SCHAN", "GTUNER", "STUNER",
            "GPICT", "SPICT", "CCAPTURE", "GWIN", "SWIN", "GFBUF",
            "SFBUF", "KEY", "GFREQ", "SFREQ", "GAUDIO", "SAUDIO",
            "SYNC", "MCAPTURE", "GMBUF", "GUNIT", "GCAPTURE", "SCAPTURE",
            "SPLAYMODE", "SWRITEMODE", "GPLAYINFO", "SMICROCODE",
            "GVBIFMT", "SVBIFMT"
      };

      #define V4L1_IOCTL(cmd) \
            ((_IOC_NR((cmd)) < ARRAY_SIZE(v4l1_ioctls)) ? \
            v4l1_ioctls[_IOC_NR((cmd))] : "?")

      cam = (struct w9968cf_device*)video_get_drvdata(video_devdata(filp));

      switch (cmd) {

      case VIDIOCGCAP: /* get video capability */
      {
            struct video_capability cap = {
                  .type = VID_TYPE_CAPTURE | VID_TYPE_SCALES,
                  .channels = 1,
                  .audios = 0,
                  .minwidth = cam->minwidth,
                  .minheight = cam->minheight,
            };
            sprintf(cap.name, "W996[87]CF USB Camera #%d",
                  cam->v4ldev->num);
            cap.maxwidth = (cam->upscaling && w9968cf_vpp)
                         ? max((u16)W9968CF_MAX_WIDTH, cam->maxwidth)
                         : cam->maxwidth;
            cap.maxheight = (cam->upscaling && w9968cf_vpp)
                        ? max((u16)W9968CF_MAX_HEIGHT, cam->maxheight)
                          : cam->maxheight;

            if (copy_to_user(arg, &cap, sizeof(cap)))
                  return -EFAULT;

            DBG(5, "VIDIOCGCAP successfully called")
            return 0;
      }

      case VIDIOCGCHAN: /* get video channel informations */
      {
            struct video_channel chan;
            if (copy_from_user(&chan, arg, sizeof(chan)))
                  return -EFAULT;

            if (chan.channel != 0)
                  return -EINVAL;

            strcpy(chan.name, "Camera");
            chan.tuners = 0;
            chan.flags = 0;
            chan.type = VIDEO_TYPE_CAMERA;
            chan.norm = VIDEO_MODE_AUTO;

            if (copy_to_user(arg, &chan, sizeof(chan)))
                  return -EFAULT;

            DBG(5, "VIDIOCGCHAN successfully called")
            return 0;
      }

      case VIDIOCSCHAN: /* set active channel */
      {
            struct video_channel chan;

            if (copy_from_user(&chan, arg, sizeof(chan)))
                  return -EFAULT;

            if (chan.channel != 0)
                  return -EINVAL;

            DBG(5, "VIDIOCSCHAN successfully called")
            return 0;
      }

      case VIDIOCGPICT: /* get image properties of the picture */
      {
            if (w9968cf_sensor_get_picture(cam))
                  return -EIO;

            if (copy_to_user(arg, &cam->picture, sizeof(cam->picture)))
                  return -EFAULT;

            DBG(5, "VIDIOCGPICT successfully called")
            return 0;
      }

      case VIDIOCSPICT: /* change picture settings */
      {
            struct video_picture pict;
            int err = 0;

            if (copy_from_user(&pict, arg, sizeof(pict)))
                  return -EFAULT;

            if ( (cam->force_palette || !w9968cf_vpp)
                 && pict.palette != cam->picture.palette ) {
                  DBG(4, "Palette %s rejected: only %s is allowed",
                      symbolic(v4l1_plist, pict.palette),
                      symbolic(v4l1_plist, cam->picture.palette))
                  return -EINVAL;
            }

            if (!w9968cf_valid_palette(pict.palette)) {
                  DBG(4, "Palette %s not supported. VIDIOCSPICT failed",
                      symbolic(v4l1_plist, pict.palette))
                  return -EINVAL;
            }

            if (!cam->force_palette) {
               if (cam->decompression == 0) {
                  if (w9968cf_need_decompression(pict.palette)) {
                   DBG(4, "Decompression disabled: palette %s is not "
                        "allowed. VIDIOCSPICT failed",
                       symbolic(v4l1_plist, pict.palette))
                   return -EINVAL;
                  }
               } else if (cam->decompression == 1) {
                  if (!w9968cf_need_decompression(pict.palette)) {
                   DBG(4, "Decompression forced: palette %s is not "
                        "allowed. VIDIOCSPICT failed",
                       symbolic(v4l1_plist, pict.palette))
                   return -EINVAL;
                  }
               }
            }

            if (pict.depth != w9968cf_valid_depth(pict.palette)) {
                  DBG(4, "Requested depth %u bpp is not valid for %s "
                         "palette: ignored and changed to %u bpp",
                      pict.depth, symbolic(v4l1_plist, pict.palette),
                      w9968cf_valid_depth(pict.palette))
                  pict.depth = w9968cf_valid_depth(pict.palette);
            }

            if (pict.palette != cam->picture.palette) {
                  if(*cam->requested_frame
                     || cam->frame_current->queued) {
                        err = wait_event_interruptible
                              ( cam->wait_queue,
                              cam->disconnected ||
                              (!*cam->requested_frame &&
                               !cam->frame_current->queued) );
                        if (err)
                              return err;
                        if (cam->disconnected)
                              return -ENODEV;
                  }

                  if (w9968cf_stop_transfer(cam))
                        goto ioctl_fail;

                  if (w9968cf_set_picture(cam, pict))
                        goto ioctl_fail;

                  if (w9968cf_start_transfer(cam))
                        goto ioctl_fail;

            } else if (w9968cf_sensor_update_picture(cam, pict))
                  return -EIO;


            DBG(5, "VIDIOCSPICT successfully called")
            return 0;
      }

      case VIDIOCSWIN: /* set capture area */
      {
            struct video_window win;
            int err = 0;

            if (copy_from_user(&win, arg, sizeof(win)))
                  return -EFAULT;

            DBG(6, "VIDIOCSWIN called: clipcount=%d, flags=%u, "
                   "x=%u, y=%u, %ux%u", win.clipcount, win.flags,
                win.x, win.y, win.width, win.height)

            if (win.clipcount != 0 || win.flags != 0)
                  return -EINVAL;

            if ((err = w9968cf_adjust_window_size(cam, &win.width,
                                          &win.height))) {
                  DBG(4, "Resolution not supported (%ux%u). "
                         "VIDIOCSWIN failed", win.width, win.height)
                  return err;
            }

            if (win.x != cam->window.x ||
                win.y != cam->window.y ||
                win.width != cam->window.width ||
                win.height != cam->window.height) {
                  if(*cam->requested_frame
                     || cam->frame_current->queued) {
                        err = wait_event_interruptible
                              ( cam->wait_queue,
                              cam->disconnected ||
                              (!*cam->requested_frame &&
                               !cam->frame_current->queued) );
                        if (err)
                              return err;
                        if (cam->disconnected)
                              return -ENODEV;
                  }

                  if (w9968cf_stop_transfer(cam))
                        goto ioctl_fail;

                  /* This _must_ be called before set_window() */
                  if (w9968cf_set_picture(cam, cam->picture))
                        goto ioctl_fail;

                  if (w9968cf_set_window(cam, win))
                        goto ioctl_fail;

                  if (w9968cf_start_transfer(cam))
                        goto ioctl_fail;
            }

            DBG(5, "VIDIOCSWIN successfully called. ")
            return 0;
      }

      case VIDIOCGWIN: /* get current window properties */
      {
            if (copy_to_user(arg,&cam->window,sizeof(struct video_window)))
                  return -EFAULT;

            DBG(5, "VIDIOCGWIN successfully called")
            return 0;
      }

      case VIDIOCGMBUF: /* request for memory (mapped) buffer */
      {
            struct video_mbuf mbuf;
            u8 i;

            mbuf.size = cam->nbuffers * cam->frame[0].size;
            mbuf.frames = cam->nbuffers;
            for (i = 0; i < cam->nbuffers; i++)
                  mbuf.offsets[i] = (unsigned long)cam->frame[i].buffer -
                                (unsigned long)cam->frame[0].buffer;

            if (copy_to_user(arg, &mbuf, sizeof(mbuf)))
                  return -EFAULT;

            DBG(5, "VIDIOCGMBUF successfully called")
            return 0;
      }

      case VIDIOCMCAPTURE: /* start the capture to a frame */
      {
            struct video_mmap mmap;
            struct w9968cf_frame_t* fr;
            u32 w, h;
            int err = 0;

            if (copy_from_user(&mmap, arg, sizeof(mmap)))
                  return -EFAULT;

            DBG(6, "VIDIOCMCAPTURE called: frame #%u, format=%s, %dx%d",
                mmap.frame, symbolic(v4l1_plist, mmap.format),
                mmap.width, mmap.height)

            if (mmap.frame >= cam->nbuffers) {
                  DBG(4, "Invalid frame number (%u). "
                         "VIDIOCMCAPTURE failed", mmap.frame)
                  return -EINVAL;
            }

            if (mmap.format!=cam->picture.palette &&
                (cam->force_palette || !w9968cf_vpp)) {
                  DBG(4, "Palette %s rejected: only %s is allowed",
                      symbolic(v4l1_plist, mmap.format),
                      symbolic(v4l1_plist, cam->picture.palette))
                  return -EINVAL;
            }

            if (!w9968cf_valid_palette(mmap.format)) {
                  DBG(4, "Palette %s not supported. "
                         "VIDIOCMCAPTURE failed",
                      symbolic(v4l1_plist, mmap.format))
                  return -EINVAL;
            }

            if (!cam->force_palette) {
               if (cam->decompression == 0) {
                  if (w9968cf_need_decompression(mmap.format)) {
                   DBG(4, "Decompression disabled: palette %s is not "
                        "allowed. VIDIOCSPICT failed",
                       symbolic(v4l1_plist, mmap.format))
                   return -EINVAL;
                  }
               } else if (cam->decompression == 1) {
                  if (!w9968cf_need_decompression(mmap.format)) {
                   DBG(4, "Decompression forced: palette %s is not "
                        "allowed. VIDIOCSPICT failed",
                       symbolic(v4l1_plist, mmap.format))
                   return -EINVAL;
                  }
               }
            }

            w = mmap.width; h = mmap.height;
            err = w9968cf_adjust_window_size(cam, &w, &h);
            mmap.width = w; mmap.height = h;
            if (err) {
                  DBG(4, "Resolution not supported (%dx%d). "
                         "VIDIOCMCAPTURE failed",
                      mmap.width, mmap.height)
                  return err;
            }

            fr = &cam->frame[mmap.frame];

            if (mmap.width  != cam->window.width ||
                mmap.height != cam->window.height ||
                mmap.format != cam->picture.palette) {

                  struct video_window win;
                  struct video_picture pict;

                  if(*cam->requested_frame
                     || cam->frame_current->queued) {
                        DBG(6, "VIDIOCMCAPTURE. Change settings for "
                               "frame #%u: %dx%d, format %s. Wait...",
                            mmap.frame, mmap.width, mmap.height,
                            symbolic(v4l1_plist, mmap.format))
                        err = wait_event_interruptible
                              ( cam->wait_queue,
                              cam->disconnected ||
                              (!*cam->requested_frame &&
                               !cam->frame_current->queued) );
                        if (err)
                              return err;
                        if (cam->disconnected)
                              return -ENODEV;
                  }

                  memcpy(&win, &cam->window, sizeof(win));
                  memcpy(&pict, &cam->picture, sizeof(pict));
                  win.width = mmap.width;
                  win.height = mmap.height;
                  pict.palette = mmap.format;

                  if (w9968cf_stop_transfer(cam))
                        goto ioctl_fail;

                  /* This before set_window */
                  if (w9968cf_set_picture(cam, pict))
                        goto ioctl_fail;

                  if (w9968cf_set_window(cam, win))
                        goto ioctl_fail;

                  if (w9968cf_start_transfer(cam))
                        goto ioctl_fail;

            } else      if (fr->queued) {

                  DBG(6, "Wait until frame #%u is free", mmap.frame)

                  err = wait_event_interruptible(cam->wait_queue,
                                           cam->disconnected ||
                                           (!fr->queued));
                  if (err)
                        return err;
                  if (cam->disconnected)
                        return -ENODEV;
            }

            w9968cf_push_frame(cam, mmap.frame);
            DBG(5, "VIDIOCMCAPTURE(%u): successfully called", mmap.frame)
            return 0;
      }

      case VIDIOCSYNC: /* wait until the capture of a frame is finished */
      {
            unsigned int f_num;
            struct w9968cf_frame_t* fr;
            int err = 0;

            if (copy_from_user(&f_num, arg, sizeof(f_num)))
                  return -EFAULT;

            if (f_num >= cam->nbuffers) {
                  DBG(4, "Invalid frame number (%u). "
                         "VIDIOCMCAPTURE failed", f_num)
                  return -EINVAL;
            }

            DBG(6, "VIDIOCSYNC called for frame #%u", f_num)

            fr = &cam->frame[f_num];

            switch (fr->status) {
            case F_UNUSED:
                  if (!fr->queued) {
                        DBG(4, "VIDIOSYNC: Frame #%u not requested!",
                            f_num)
                        return -EFAULT;
                  }
            case F_ERROR:
            case F_GRABBING:
                  err = wait_event_interruptible(cam->wait_queue,
                                           (fr->status == F_READY)
                                           || cam->disconnected);
                  if (err)
                        return err;
                  if (cam->disconnected)
                        return -ENODEV;
                  break;
            case F_READY:
                  break;
            }

            if (w9968cf_vpp)
                  w9968cf_postprocess_frame(cam, fr);

            fr->status = F_UNUSED;

            DBG(5, "VIDIOCSYNC(%u) successfully called", f_num)
            return 0;
      }

      case VIDIOCGUNIT:/* report the unit numbers of the associated devices*/
      {
            struct video_unit unit = {
                  .video = cam->v4ldev->minor,
                  .vbi = VIDEO_NO_UNIT,
                  .radio = VIDEO_NO_UNIT,
                  .audio = VIDEO_NO_UNIT,
                  .teletext = VIDEO_NO_UNIT,
            };

            if (copy_to_user(arg, &unit, sizeof(unit)))
                  return -EFAULT;

            DBG(5, "VIDIOCGUNIT successfully called")
            return 0;
      }

      case VIDIOCKEY:
            return 0;

      case VIDIOCGFBUF:
      {
            if (clear_user(arg, sizeof(struct video_buffer)))
                  return -EFAULT;

            DBG(5, "VIDIOCGFBUF successfully called")
            return 0;
      }

      case VIDIOCGTUNER:
      {
            struct video_tuner tuner;
            if (copy_from_user(&tuner, arg, sizeof(tuner)))
                  return -EFAULT;

            if (tuner.tuner != 0)
                  return -EINVAL;

            strcpy(tuner.name, "no_tuner");
            tuner.rangelow = 0;
            tuner.rangehigh = 0;
            tuner.flags = VIDEO_TUNER_NORM;
            tuner.mode = VIDEO_MODE_AUTO;
            tuner.signal = 0xffff;

            if (copy_to_user(arg, &tuner, sizeof(tuner)))
                  return -EFAULT;

            DBG(5, "VIDIOCGTUNER successfully called")
            return 0;
      }

      case VIDIOCSTUNER:
      {
            struct video_tuner tuner;
            if (copy_from_user(&tuner, arg, sizeof(tuner)))
                  return -EFAULT;

            if (tuner.tuner != 0)
                  return -EINVAL;

            if (tuner.mode != VIDEO_MODE_AUTO)
                  return -EINVAL;

            DBG(5, "VIDIOCSTUNER successfully called")
            return 0;
      }

      case VIDIOCSFBUF:
      case VIDIOCCAPTURE:
      case VIDIOCGFREQ:
      case VIDIOCSFREQ:
      case VIDIOCGAUDIO:
      case VIDIOCSAUDIO:
      case VIDIOCSPLAYMODE:
      case VIDIOCSWRITEMODE:
      case VIDIOCGPLAYINFO:
      case VIDIOCSMICROCODE:
      case VIDIOCGVBIFMT:
      case VIDIOCSVBIFMT:
            DBG(4, "Unsupported V4L1 IOCtl: VIDIOC%s "
                   "(type 0x%01X, "
                   "n. 0x%01X, "
                   "dir. 0x%01X, "
                   "size 0x%02X)",
                V4L1_IOCTL(cmd),
                _IOC_TYPE(cmd),_IOC_NR(cmd),_IOC_DIR(cmd),_IOC_SIZE(cmd))

            return -EINVAL;

      default:
            DBG(4, "Invalid V4L1 IOCtl: VIDIOC%s "
                   "type 0x%01X, "
                   "n. 0x%01X, "
                   "dir. 0x%01X, "
                   "size 0x%02X",
                V4L1_IOCTL(cmd),
                _IOC_TYPE(cmd),_IOC_NR(cmd),_IOC_DIR(cmd),_IOC_SIZE(cmd))

            return -ENOIOCTLCMD;

      } /* end of switch */

ioctl_fail:
      cam->misconfigured = 1;
      DBG(1, "VIDIOC%s failed because of hardware problems. "
             "To use the camera, close and open it again.", V4L1_IOCTL(cmd))
      return -EFAULT;
}


static const struct v4l2_file_operations w9968cf_fops = {
      .owner =   THIS_MODULE,
      .open =    w9968cf_open,
      .release = w9968cf_release,
      .read =    w9968cf_read,
      .ioctl =   w9968cf_ioctl,
      .mmap =    w9968cf_mmap,
};



/****************************************************************************
 * USB probe and V4L registration, disconnect and id_table[] definition     *
 ****************************************************************************/

static int
w9968cf_usb_probe(struct usb_interface* intf, const struct usb_device_id* id)
{
      struct usb_device *udev = interface_to_usbdev(intf);
      struct w9968cf_device* cam;
      int err = 0;
      enum w9968cf_model_id mod_id;
      struct list_head* ptr;
      u8 sc = 0; /* number of simultaneous cameras */
      static unsigned short dev_nr; /* 0 - we are handling device number n */
      static unsigned short addrs[] = {
            OV7xx0_SID,
            OV6xx0_SID,
            I2C_CLIENT_END
      };

      if (le16_to_cpu(udev->descriptor.idVendor)  == winbond_id_table[0].idVendor &&
          le16_to_cpu(udev->descriptor.idProduct) == winbond_id_table[0].idProduct)
            mod_id = W9968CF_MOD_CLVBWGP; /* see camlist[] table */
      else if (le16_to_cpu(udev->descriptor.idVendor)  == winbond_id_table[1].idVendor &&
             le16_to_cpu(udev->descriptor.idProduct) == winbond_id_table[1].idProduct)
            mod_id = W9968CF_MOD_GENERIC; /* see camlist[] table */
      else
            return -ENODEV;

      cam = (struct w9968cf_device*)
              kzalloc(sizeof(struct w9968cf_device), GFP_KERNEL);
      if (!cam)
            return -ENOMEM;

      err = v4l2_device_register(&intf->dev, &cam->v4l2_dev);
      if (err)
            goto fail0;

      mutex_init(&cam->dev_mutex);
      mutex_lock(&cam->dev_mutex);

      cam->usbdev = udev;

      DBG(2, "%s detected", symbolic(camlist, mod_id))

      if (simcams > W9968CF_MAX_DEVICES)
            simcams = W9968CF_SIMCAMS;

      /* How many cameras are connected ? */
      mutex_lock(&w9968cf_devlist_mutex);
      list_for_each(ptr, &w9968cf_dev_list)
            sc++;
      mutex_unlock(&w9968cf_devlist_mutex);

      if (sc >= simcams) {
            DBG(2, "Device rejected: too many connected cameras "
                   "(max. %u)", simcams)
            err = -EPERM;
            goto fail;
      }


      /* Allocate 2 bytes of memory for camera control USB transfers */
      if (!(cam->control_buffer = kzalloc(2, GFP_KERNEL))) {
            DBG(1,"Couldn't allocate memory for camera control transfers")
            err = -ENOMEM;
            goto fail;
      }

      /* Allocate 8 bytes of memory for USB data transfers to the FSB */
      if (!(cam->data_buffer = kzalloc(8, GFP_KERNEL))) {
            DBG(1, "Couldn't allocate memory for data "
                   "transfers to the FSB")
            err = -ENOMEM;
            goto fail;
      }

      /* Register the V4L device */
      cam->v4ldev = video_device_alloc();
      if (!cam->v4ldev) {
            DBG(1, "Could not allocate memory for a V4L structure")
            err = -ENOMEM;
            goto fail;
      }

      strcpy(cam->v4ldev->name, symbolic(camlist, mod_id));
      cam->v4ldev->fops = &w9968cf_fops;
      cam->v4ldev->minor = video_nr[dev_nr];
      cam->v4ldev->release = video_device_release;
      video_set_drvdata(cam->v4ldev, cam);
      cam->v4ldev->v4l2_dev = &cam->v4l2_dev;

      err = video_register_device(cam->v4ldev, VFL_TYPE_GRABBER,
                            video_nr[dev_nr]);
      if (err) {
            DBG(1, "V4L device registration failed")
            if (err == -ENFILE && video_nr[dev_nr] == -1)
                  DBG(2, "Couldn't find a free /dev/videoX node")
            video_nr[dev_nr] = -1;
            dev_nr = (dev_nr < W9968CF_MAX_DEVICES-1) ? dev_nr+1 : 0;
            goto fail;
      }

      DBG(2, "V4L device registered as /dev/video%d", cam->v4ldev->num)

      /* Set some basic constants */
      w9968cf_configure_camera(cam, udev, mod_id, dev_nr);

      /* Add a new entry into the list of V4L registered devices */
      mutex_lock(&w9968cf_devlist_mutex);
      list_add(&cam->v4llist, &w9968cf_dev_list);
      mutex_unlock(&w9968cf_devlist_mutex);
      dev_nr = (dev_nr < W9968CF_MAX_DEVICES-1) ? dev_nr+1 : 0;

      w9968cf_turn_on_led(cam);

      w9968cf_i2c_init(cam);
      cam->sensor_sd = v4l2_i2c_new_probed_subdev(&cam->v4l2_dev,
                  &cam->i2c_adapter,
                  "ovcamchip", "ovcamchip", addrs);

      usb_set_intfdata(intf, cam);
      mutex_unlock(&cam->dev_mutex);

      err = w9968cf_sensor_init(cam);
      return 0;

fail: /* Free unused memory */
      kfree(cam->control_buffer);
      kfree(cam->data_buffer);
      if (cam->v4ldev)
            video_device_release(cam->v4ldev);
      mutex_unlock(&cam->dev_mutex);
      v4l2_device_unregister(&cam->v4l2_dev);
fail0:
      kfree(cam);
      return err;
}


static void w9968cf_usb_disconnect(struct usb_interface* intf)
{
      struct w9968cf_device* cam =
         (struct w9968cf_device*)usb_get_intfdata(intf);

      if (cam) {
            down_write(&w9968cf_disconnect);
            /* Prevent concurrent accesses to data */
            mutex_lock(&cam->dev_mutex);

            cam->disconnected = 1;

            DBG(2, "Disconnecting %s...", symbolic(camlist, cam->id));

            v4l2_device_disconnect(&cam->v4l2_dev);

            wake_up_interruptible_all(&cam->open);

            if (cam->users) {
                  DBG(2, "The device is open (/dev/video%d)! "
                         "Process name: %s. Deregistration and memory "
                         "deallocation are deferred on close.",
                      cam->v4ldev->num, cam->command)
                  cam->misconfigured = 1;
                  w9968cf_stop_transfer(cam);
                  wake_up_interruptible(&cam->wait_queue);
            } else
                  w9968cf_release_resources(cam);

            mutex_unlock(&cam->dev_mutex);
            up_write(&w9968cf_disconnect);

            if (!cam->users) {
                  kfree(cam);
            }
      }
}


static struct usb_driver w9968cf_usb_driver = {
      .name =       "w9968cf",
      .id_table =   winbond_id_table,
      .probe =      w9968cf_usb_probe,
      .disconnect = w9968cf_usb_disconnect,
};



/****************************************************************************
 * Module init, exit and intermodule communication                          *
 ****************************************************************************/

static int __init w9968cf_module_init(void)
{
      int err;

      KDBG(2, W9968CF_MODULE_NAME" "W9968CF_MODULE_VERSION)
      KDBG(3, W9968CF_MODULE_AUTHOR)

      if ((err = usb_register(&w9968cf_usb_driver)))
            return err;

      return 0;
}


static void __exit w9968cf_module_exit(void)
{
      /* w9968cf_usb_disconnect() will be called */
      usb_deregister(&w9968cf_usb_driver);

      KDBG(2, W9968CF_MODULE_NAME" deregistered")
}


module_init(w9968cf_module_init);
module_exit(w9968cf_module_exit);


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