/***************************************************************************
 * 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 */
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 = {
                .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;