/*
 * Pixart PAC7302 driver
 *
 * Copyright (C) 2008-2012 Jean-Francois Moine <http://moinejf.free.fr>
 * Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li
 *
 * Separated from Pixart PAC7311 library by Márton Németh
 * Camera button input handling by Márton Németh <nm127@freemail.hu>
 * Copyright (C) 2009-2010 Márton Németh <nm127@freemail.hu>
 *
 * 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
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/*
 * Some documentation about various registers as determined by trial and error.
 *
 * Register page 0:
 *
 * Address      Description
 * 0x01         Red balance control
 * 0x02         Green balance control
 * 0x03         Blue balance control
 *                   The Windows driver uses a quadratic approach to map
 *                   the settable values (0-200) on register values:
 *                   min=0x20, default=0x40, max=0x80
 * 0x0f-0x20    Color and saturation control
 * 0xa2-0xab    Brightness, contrast and gamma control
 * 0xb6         Sharpness control (bits 0-4)
 *
 * Register page 1:
 *
 * Address      Description
 * 0x78         Global control, bit 6 controls the LED (inverted)
 * 0x80         Compression balance, 2 interesting settings:
 *              0x0f Default
 *              0x50 Values >= this switch the camera to a lower compression,
 *                   using the same table for both luminance and chrominance.
 *                   This gives a sharper picture. Only usable when running
 *                   at < 15 fps! Note currently the driver does not use this
 *                   as the quality gain is small and the generated JPG-s are
 *                   only understood by v4l-utils >= 0.8.9
 *
 * Register page 3:
 *
 * Address      Description
 * 0x02         Clock divider 3-63, fps = 90 / val. Must be a multiple of 3 on
 *              the 7302, so one of 3, 6, 9, ..., except when between 6 and 12?
 * 0x03         Variable framerate ctrl reg2==3: 0 -> ~30 fps, 255 -> ~22fps
 * 0x04         Another var framerate ctrl reg2==3, reg3==0: 0 -> ~30 fps,
 *              63 -> ~27 fps, the 2 msb's must always be 1 !!
 * 0x05         Another var framerate ctrl reg2==3, reg3==0, reg4==0xc0:
 *              1 -> ~30 fps, 2 -> ~20 fps
 * 0x0e         Exposure bits 0-7, 0-448, 0 = use full frame time
 * 0x0f         Exposure bit 8, 0-448, 448 = no exposure at all
 * 0x10         Gain 0-31
 * 0x12         Another gain 0-31, unlike 0x10 this one seems to start with an
 *              amplification value of 1 rather then 0 at its lowest setting
 * 0x21         Bitfield: 0-1 unused, 2-3 vflip/hflip, 4-5 unknown, 6-7 unused
 * 0x80         Another framerate control, best left at 1, moving it from 1 to
 *              2 causes the framerate to become 3/4th of what it was, and
 *              also seems to cause pixel averaging, resulting in an effective
 *              resolution of 320x240 and thus a much blockier image
 *
 * The registers are accessed in the following functions:
 *
 * Page | Register   | Function
 * -----+------------+---------------------------------------------------
 *  0   | 0x01       | setredbalance()
 *  0   | 0x03       | setbluebalance()
 *  0   | 0x0f..0x20 | setcolors()
 *  0   | 0xa2..0xab | setbrightcont()
 *  0   | 0xb6       | setsharpness()
 *  0   | 0xc6       | setwhitebalance()
 *  0   | 0xdc       | setbrightcont(), setcolors()
 *  3   | 0x02       | setexposure()
 *  3   | 0x10, 0x12 | setgain()
 *  3   | 0x11       | setcolors(), setgain(), setexposure(), sethvflip()
 *  3   | 0x21       | sethvflip()
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/input.h>
#include <media/v4l2-chip-ident.h>
#include "gspca.h"
/* Include pac common sof detection functions */
#include "pac_common.h"

#define PAC7302_RGB_BALANCE_MIN           0
#define PAC7302_RGB_BALANCE_MAX         200
#define PAC7302_RGB_BALANCE_DEFAULT     100
#define PAC7302_GAIN_DEFAULT             15
#define PAC7302_GAIN_KNEE                42
#define PAC7302_EXPOSURE_DEFAULT         66 /* 33 ms / 30 fps */
#define PAC7302_EXPOSURE_KNEE           133 /* 66 ms / 15 fps */

MODULE_AUTHOR("Jean-Francois Moine <http://moinejf.free.fr>, "
                "Thomas Kaiser thomas@kaiser-linux.li");
MODULE_DESCRIPTION("Pixart PAC7302");
MODULE_LICENSE("GPL");

struct sd {
        struct gspca_dev gspca_dev;             /* !! must be the first item */

        struct { /* brightness / contrast cluster */
                struct v4l2_ctrl *brightness;
                struct v4l2_ctrl *contrast;
        };
        struct v4l2_ctrl *saturation;
        struct v4l2_ctrl *white_balance;
        struct v4l2_ctrl *red_balance;
        struct v4l2_ctrl *blue_balance;
        struct { /* flip cluster */
                struct v4l2_ctrl *hflip;
                struct v4l2_ctrl *vflip;
        };
        struct v4l2_ctrl *sharpness;
        u8 flags;
#define FL_HFLIP 0x01           /* mirrored by default */
#define FL_VFLIP 0x02           /* vertical flipped by default */

        u8 sof_read;
        s8 autogain_ignore_frames;

        atomic_t avg_lum;
};

static const struct v4l2_pix_format vga_mode[] = {
        {640, 480, V4L2_PIX_FMT_PJPG, V4L2_FIELD_NONE,
                .bytesperline = 640,
                .sizeimage = 640 * 480 * 3 / 8 + 590,
                .colorspace = V4L2_COLORSPACE_JPEG,
        },
};

#define LOAD_PAGE3              255
#define END_OF_SEQUENCE         0

static const u8 init_7302[] = {
/*      index,value */
        0xff, 0x01,             /* page 1 */
        0x78, 0x00,             /* deactivate */
        0xff, 0x01,
        0x78, 0x40,             /* led off */
};
static const u8 start_7302[] = {
/*      index, len, [value]* */
        0xff, 1,        0x00,           /* page 0 */
        0x00, 12,       0x01, 0x40, 0x40, 0x40, 0x01, 0xe0, 0x02, 0x80,
                        0x00, 0x00, 0x00, 0x00,
        0x0d, 24,       0x03, 0x01, 0x00, 0xb5, 0x07, 0xcb, 0x00, 0x00,
                        0x07, 0xc8, 0x00, 0xea, 0x07, 0xcf, 0x07, 0xf7,
                        0x07, 0x7e, 0x01, 0x0b, 0x00, 0x00, 0x00, 0x11,
        0x26, 2,        0xaa, 0xaa,
        0x2e, 1,        0x31,
        0x38, 1,        0x01,
        0x3a, 3,        0x14, 0xff, 0x5a,
        0x43, 11,       0x00, 0x0a, 0x18, 0x11, 0x01, 0x2c, 0x88, 0x11,
                        0x00, 0x54, 0x11,
        0x55, 1,        0x00,
        0x62, 4,        0x10, 0x1e, 0x1e, 0x18,
        0x6b, 1,        0x00,
        0x6e, 3,        0x08, 0x06, 0x00,
        0x72, 3,        0x00, 0xff, 0x00,
        0x7d, 23,       0x01, 0x01, 0x58, 0x46, 0x50, 0x3c, 0x50, 0x3c,
                        0x54, 0x46, 0x54, 0x56, 0x52, 0x50, 0x52, 0x50,
                        0x56, 0x64, 0xa4, 0x00, 0xda, 0x00, 0x00,
        0xa2, 10,       0x22, 0x2c, 0x3c, 0x54, 0x69, 0x7c, 0x9c, 0xb9,
                        0xd2, 0xeb,
        0xaf, 1,        0x02,
        0xb5, 2,        0x08, 0x08,
        0xb8, 2,        0x08, 0x88,
        0xc4, 4,        0xae, 0x01, 0x04, 0x01,
        0xcc, 1,        0x00,
        0xd1, 11,       0x01, 0x30, 0x49, 0x5e, 0x6f, 0x7f, 0x8e, 0xa9,
                        0xc1, 0xd7, 0xec,
        0xdc, 1,        0x01,
        0xff, 1,        0x01,           /* page 1 */
        0x12, 3,        0x02, 0x00, 0x01,
        0x3e, 2,        0x00, 0x00,
        0x76, 5,        0x01, 0x20, 0x40, 0x00, 0xf2,
        0x7c, 1,        0x00,
        0x7f, 10,       0x4b, 0x0f, 0x01, 0x2c, 0x02, 0x58, 0x03, 0x20,
                        0x02, 0x00,
        0x96, 5,        0x01, 0x10, 0x04, 0x01, 0x04,
        0xc8, 14,       0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00,
                        0x07, 0x00, 0x01, 0x07, 0x04, 0x01,
        0xd8, 1,        0x01,
        0xdb, 2,        0x00, 0x01,
        0xde, 7,        0x00, 0x01, 0x04, 0x04, 0x00, 0x00, 0x00,
        0xe6, 4,        0x00, 0x00, 0x00, 0x01,
        0xeb, 1,        0x00,
        0xff, 1,        0x02,           /* page 2 */
        0x22, 1,        0x00,
        0xff, 1,        0x03,           /* page 3 */
        0, LOAD_PAGE3,                  /* load the page 3 */
        0x11, 1,        0x01,
        0xff, 1,        0x02,           /* page 2 */
        0x13, 1,        0x00,
        0x22, 4,        0x1f, 0xa4, 0xf0, 0x96,
        0x27, 2,        0x14, 0x0c,
        0x2a, 5,        0xc8, 0x00, 0x18, 0x12, 0x22,
        0x64, 8,        0x00, 0x00, 0xf0, 0x01, 0x14, 0x44, 0x44, 0x44,
        0x6e, 1,        0x08,
        0xff, 1,        0x01,           /* page 1 */
        0x78, 1,        0x00,
        0, END_OF_SEQUENCE              /* end of sequence */
};

#define SKIP            0xaa
/* page 3 - the value SKIP says skip the index - see reg_w_page() */
static const u8 page3_7302[] = {
        0x90, 0x40, 0x03, 0x00, 0xc0, 0x01, 0x14, 0x16,
        0x14, 0x12, 0x00, 0x00, 0x00, 0x02, 0x33, 0x00,
        0x0f, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x47, 0x01, 0xb3, 0x01, 0x00,
        0x00, 0x08, 0x00, 0x00, 0x0d, 0x00, 0x00, 0x21,
        0x00, 0x00, 0x00, 0x54, 0xf4, 0x02, 0x52, 0x54,
        0xa4, 0xb8, 0xe0, 0x2a, 0xf6, 0x00, 0x00, 0x00,
        0x00, 0x1e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0xfc, 0x00, 0xf2, 0x1f, 0x04, 0x00, 0x00,
        SKIP, 0x00, 0x00, 0xc0, 0xc0, 0x10, 0x00, 0x00,
        0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x40, 0xff, 0x03, 0x19, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0xc8, 0xc8, 0xc8,
        0xc8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50,
        0x08, 0x10, 0x24, 0x40, 0x00, 0x00, 0x00, 0x00,
        0x01, 0x00, 0x02, 0x47, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x02, 0xfa, 0x00, 0x64, 0x5a, 0x28, 0x00,
        0x00
};

static void reg_w_buf(struct gspca_dev *gspca_dev,
                u8 index,
                  const u8 *buffer, int len)
{
        int ret;

        if (gspca_dev->usb_err < 0)
                return;
        memcpy(gspca_dev->usb_buf, buffer, len);
        ret = usb_control_msg(gspca_dev->dev,
                        usb_sndctrlpipe(gspca_dev->dev, 0),
                        0,              /* request */
                        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        0,              /* value */
                        index, gspca_dev->usb_buf, len,
                        500);
        if (ret < 0) {
                pr_err("reg_w_buf failed i: %02x error %d\n",
                       index, ret);
                gspca_dev->usb_err = ret;
        }
}


static void reg_w(struct gspca_dev *gspca_dev,
                u8 index,
                u8 value)
{
        int ret;

        if (gspca_dev->usb_err < 0)
                return;
        gspca_dev->usb_buf[0] = value;
        ret = usb_control_msg(gspca_dev->dev,
                        usb_sndctrlpipe(gspca_dev->dev, 0),
                        0,                      /* request */
                        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                        0, index, gspca_dev->usb_buf, 1,
                        500);
        if (ret < 0) {
                pr_err("reg_w() failed i: %02x v: %02x error %d\n",
                       index, value, ret);
                gspca_dev->usb_err = ret;
        }
}

static void reg_w_seq(struct gspca_dev *gspca_dev,
                const u8 *seq, int len)
{
        while (--len >= 0) {
                reg_w(gspca_dev, seq[0], seq[1]);
                seq += 2;
        }
}

/* load the beginning of a page */
static void reg_w_page(struct gspca_dev *gspca_dev,
                        const u8 *page, int len)
{
        int index;
        int ret = 0;

        if (gspca_dev->usb_err < 0)
                return;
        for (index = 0; index < len; index++) {
                if (page[index] == SKIP)                /* skip this index */
                        continue;
                gspca_dev->usb_buf[0] = page[index];
                ret = usb_control_msg(gspca_dev->dev,
                                usb_sndctrlpipe(gspca_dev->dev, 0),
                                0,                      /* request */
                        USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                0, index, gspca_dev->usb_buf, 1,
                                500);
                if (ret < 0) {
                        pr_err("reg_w_page() failed i: %02x v: %02x error %d\n",
                               index, page[index], ret);
                        gspca_dev->usb_err = ret;
                        break;
                }
        }
}

/* output a variable sequence */
static void reg_w_var(struct gspca_dev *gspca_dev,
                        const u8 *seq,
                        const u8 *page3, unsigned int page3_len)
{
        int index, len;

        for (;;) {
                index = *seq++;
                len = *seq++;
                switch (len) {
                case END_OF_SEQUENCE:
                        return;
                case LOAD_PAGE3:
                        reg_w_page(gspca_dev, page3, page3_len);
                        break;
                default:
                        if (len > USB_BUF_SZ) {
                                PERR("Incorrect variable sequence");
                                return;
                        }
                        while (len > 0) {
                                if (len < 8) {
                                        reg_w_buf(gspca_dev,
                                                index, seq, len);
                                        seq += len;
                                        break;
                                }
                                reg_w_buf(gspca_dev, index, seq, 8);
                                seq += 8;
                                index += 8;
                                len -= 8;
                        }
                }
        }
        /* not reached */
}

/* this function is called at probe time for pac7302 */
static int sd_config(struct gspca_dev *gspca_dev,
                        const struct usb_device_id *id)
{
        struct sd *sd = (struct sd *) gspca_dev;
        struct cam *cam;

        cam = &gspca_dev->cam;

        cam->cam_mode = vga_mode;       /* only 640x480 */
        cam->nmodes = ARRAY_SIZE(vga_mode);

        sd->flags = id->driver_info;
        return 0;
}

static void setbrightcont(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        int i, v;
        static const u8 max[10] =
                {0x29, 0x33, 0x42, 0x5a, 0x6e, 0x80, 0x9f, 0xbb,
                 0xd4, 0xec};
        static const u8 delta[10] =
                {0x35, 0x33, 0x33, 0x2f, 0x2a, 0x25, 0x1e, 0x17,
                 0x11, 0x0b};

        reg_w(gspca_dev, 0xff, 0x00);           /* page 0 */
        for (i = 0; i < 10; i++) {
                v = max[i];
                v += (sd->brightness->val - sd->brightness->maximum)
                        * 150 / sd->brightness->maximum; /* 200 ? */
                v -= delta[i] * sd->contrast->val / sd->contrast->maximum;
                if (v < 0)
                        v = 0;
                else if (v > 0xff)
                        v = 0xff;
                reg_w(gspca_dev, 0xa2 + i, v);
        }
        reg_w(gspca_dev, 0xdc, 0x01);
}

static void setcolors(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        int i, v;
        static const int a[9] =
                {217, -212, 0, -101, 170, -67, -38, -315, 355};
        static const int b[9] =
                {19, 106, 0, 19, 106, 1, 19, 106, 1};

        reg_w(gspca_dev, 0xff, 0x03);                   /* page 3 */
        reg_w(gspca_dev, 0x11, 0x01);
        reg_w(gspca_dev, 0xff, 0x00);                   /* page 0 */
        for (i = 0; i < 9; i++) {
                v = a[i] * sd->saturation->val / sd->saturation->maximum;
                v += b[i];
                reg_w(gspca_dev, 0x0f + 2 * i, (v >> 8) & 0x07);
                reg_w(gspca_dev, 0x0f + 2 * i + 1, v);
        }
        reg_w(gspca_dev, 0xdc, 0x01);
}

static void setwhitebalance(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        reg_w(gspca_dev, 0xff, 0x00);           /* page 0 */
        reg_w(gspca_dev, 0xc6, sd->white_balance->val);

        reg_w(gspca_dev, 0xdc, 0x01);
}

static u8 rgbbalance_ctrl_to_reg_value(s32 rgb_ctrl_val)
{
        const unsigned int k = 1000;    /* precision factor */
        unsigned int norm;

        /* Normed value [0...k] */
        norm = k * (rgb_ctrl_val - PAC7302_RGB_BALANCE_MIN)
                    / (PAC7302_RGB_BALANCE_MAX - PAC7302_RGB_BALANCE_MIN);
        /* Qudratic apporach improves control at small (register) values: */
        return 64 * norm * norm / (k*k)  +  32 * norm / k  +  32;
        /* Y = 64*X*X + 32*X + 32
         * => register values 0x20-0x80; Windows driver uses these limits */

        /* NOTE: for full value range (0x00-0xff) use
         *         Y = 254*X*X + X
         *         => 254 * norm * norm / (k*k)  +  1 * norm / k        */
}

static void setredbalance(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        reg_w(gspca_dev, 0xff, 0x00);                   /* page 0 */
        reg_w(gspca_dev, 0x01,
              rgbbalance_ctrl_to_reg_value(sd->red_balance->val));

        reg_w(gspca_dev, 0xdc, 0x01);
}

static void setbluebalance(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        reg_w(gspca_dev, 0xff, 0x00);                   /* page 0 */
        reg_w(gspca_dev, 0x03,
              rgbbalance_ctrl_to_reg_value(sd->blue_balance->val));

        reg_w(gspca_dev, 0xdc, 0x01);
}

static void setgain(struct gspca_dev *gspca_dev)
{
        u8 reg10, reg12;

        if (gspca_dev->gain->val < 32) {
                reg10 = gspca_dev->gain->val;
                reg12 = 0;
        } else {
                reg10 = 31;
                reg12 = gspca_dev->gain->val - 31;
        }

        reg_w(gspca_dev, 0xff, 0x03);                   /* page 3 */
        reg_w(gspca_dev, 0x10, reg10);
        reg_w(gspca_dev, 0x12, reg12);

        /* load registers to sensor (Bit 0, auto clear) */
        reg_w(gspca_dev, 0x11, 0x01);
}

static void setexposure(struct gspca_dev *gspca_dev)
{
        u8 clockdiv;
        u16 exposure;

        /*
         * Register 2 of frame 3 contains the clock divider configuring the
         * no fps according to the formula: 90 / reg. sd->exposure is the
         * desired exposure time in 0.5 ms.
         */
        clockdiv = (90 * gspca_dev->exposure->val + 1999) / 2000;

        /*
         * Note clockdiv = 3 also works, but when running at 30 fps, depending
         * on the scene being recorded, the camera switches to another
         * quantization table for certain JPEG blocks, and we don't know how
         * to decompress these blocks. So we cap the framerate at 15 fps.
         */
        if (clockdiv < 6)
                clockdiv = 6;
        else if (clockdiv > 63)
                clockdiv = 63;

        /*
         * Register 2 MUST be a multiple of 3, except when between 6 and 12?
         * Always round up, otherwise we cannot get the desired frametime
         * using the partial frame time exposure control.
         */
        if (clockdiv < 6 || clockdiv > 12)
                clockdiv = ((clockdiv + 2) / 3) * 3;

        /*
         * frame exposure time in ms = 1000 * clockdiv / 90    ->
         * exposure = (sd->exposure / 2) * 448 / (1000 * clockdiv / 90)
         */
        exposure = (gspca_dev->exposure->val * 45 * 448) / (1000 * clockdiv);
        /* 0 = use full frametime, 448 = no exposure, reverse it */
        exposure = 448 - exposure;

        reg_w(gspca_dev, 0xff, 0x03);                   /* page 3 */
        reg_w(gspca_dev, 0x02, clockdiv);
        reg_w(gspca_dev, 0x0e, exposure & 0xff);
        reg_w(gspca_dev, 0x0f, exposure >> 8);

        /* load registers to sensor (Bit 0, auto clear) */
        reg_w(gspca_dev, 0x11, 0x01);
}

static void sethvflip(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        u8 data, hflip, vflip;

        hflip = sd->hflip->val;
        if (sd->flags & FL_HFLIP)
                hflip = !hflip;
        vflip = sd->vflip->val;
        if (sd->flags & FL_VFLIP)
                vflip = !vflip;

        reg_w(gspca_dev, 0xff, 0x03);                   /* page 3 */
        data = (hflip ? 0x08 : 0x00) | (vflip ? 0x04 : 0x00);
        reg_w(gspca_dev, 0x21, data);

        /* load registers to sensor (Bit 0, auto clear) */
        reg_w(gspca_dev, 0x11, 0x01);
}

static void setsharpness(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        reg_w(gspca_dev, 0xff, 0x00);           /* page 0 */
        reg_w(gspca_dev, 0xb6, sd->sharpness->val);

        reg_w(gspca_dev, 0xdc, 0x01);
}

/* this function is called at probe and resume time for pac7302 */
static int sd_init(struct gspca_dev *gspca_dev)
{
        reg_w_seq(gspca_dev, init_7302, sizeof(init_7302)/2);
        return gspca_dev->usb_err;
}

static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct gspca_dev *gspca_dev =
                container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
        struct sd *sd = (struct sd *)gspca_dev;

        gspca_dev->usb_err = 0;

        if (ctrl->id == V4L2_CID_AUTOGAIN && ctrl->is_new && ctrl->val) {
                /* when switching to autogain set defaults to make sure
                   we are on a valid point of the autogain gain /
                   exposure knee graph, and give this change time to
                   take effect before doing autogain. */
                gspca_dev->exposure->val    = PAC7302_EXPOSURE_DEFAULT;
                gspca_dev->gain->val        = PAC7302_GAIN_DEFAULT;
                sd->autogain_ignore_frames  = PAC_AUTOGAIN_IGNORE_FRAMES;
        }

        if (!gspca_dev->streaming)
                return 0;

        switch (ctrl->id) {
        case V4L2_CID_BRIGHTNESS:
                setbrightcont(gspca_dev);
                break;
        case V4L2_CID_SATURATION:
                setcolors(gspca_dev);
                break;
        case V4L2_CID_WHITE_BALANCE_TEMPERATURE:
                setwhitebalance(gspca_dev);
                break;
        case V4L2_CID_RED_BALANCE:
                setredbalance(gspca_dev);
                break;
        case V4L2_CID_BLUE_BALANCE:
                setbluebalance(gspca_dev);
                break;
        case V4L2_CID_AUTOGAIN:
                if (gspca_dev->exposure->is_new || (ctrl->is_new && ctrl->val))
                        setexposure(gspca_dev);
                if (gspca_dev->gain->is_new || (ctrl->is_new && ctrl->val))
                        setgain(gspca_dev);
                break;
        case V4L2_CID_HFLIP:
                sethvflip(gspca_dev);
                break;
        case V4L2_CID_SHARPNESS:
                setsharpness(gspca_dev);
                break;
        default:
                return -EINVAL;
        }
        return gspca_dev->usb_err;
}

static const struct v4l2_ctrl_ops sd_ctrl_ops = {
        .s_ctrl = sd_s_ctrl,
};

/* this function is called at probe time */
static int sd_init_controls(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;

        gspca_dev->vdev.ctrl_handler = hdl;
        v4l2_ctrl_handler_init(hdl, 12);

        sd->brightness = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_BRIGHTNESS, 0, 32, 1, 16);
        sd->contrast = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_CONTRAST, 0, 255, 1, 127);

        sd->saturation = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_SATURATION, 0, 255, 1, 127);
        sd->white_balance = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_WHITE_BALANCE_TEMPERATURE,
                                        0, 255, 1, 55);
        sd->red_balance = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_RED_BALANCE,
                                        PAC7302_RGB_BALANCE_MIN,
                                        PAC7302_RGB_BALANCE_MAX,
                                        1, PAC7302_RGB_BALANCE_DEFAULT);
        sd->blue_balance = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_BLUE_BALANCE,
                                        PAC7302_RGB_BALANCE_MIN,
                                        PAC7302_RGB_BALANCE_MAX,
                                        1, PAC7302_RGB_BALANCE_DEFAULT);

        gspca_dev->autogain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
        gspca_dev->exposure = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_EXPOSURE, 0, 1023, 1,
                                        PAC7302_EXPOSURE_DEFAULT);
        gspca_dev->gain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_GAIN, 0, 62, 1,
                                        PAC7302_GAIN_DEFAULT);

        sd->hflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                V4L2_CID_HFLIP, 0, 1, 1, 0);
        sd->vflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                V4L2_CID_VFLIP, 0, 1, 1, 0);

        sd->sharpness = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_SHARPNESS, 0, 15, 1, 8);

        if (hdl->error) {
                pr_err("Could not initialize controls\n");
                return hdl->error;
        }

        v4l2_ctrl_cluster(2, &sd->brightness);
        v4l2_ctrl_auto_cluster(3, &gspca_dev->autogain, 0, false);
        v4l2_ctrl_cluster(2, &sd->hflip);
        return 0;
}

/* -- start the camera -- */
static int sd_start(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;

        reg_w_var(gspca_dev, start_7302,
                page3_7302, sizeof(page3_7302));

        sd->sof_read = 0;
        sd->autogain_ignore_frames = 0;
        atomic_set(&sd->avg_lum, 270 + sd->brightness->val);

        /* start stream */
        reg_w(gspca_dev, 0xff, 0x01);
        reg_w(gspca_dev, 0x78, 0x01);

        return gspca_dev->usb_err;
}

static void sd_stopN(struct gspca_dev *gspca_dev)
{

        /* stop stream */
        reg_w(gspca_dev, 0xff, 0x01);
        reg_w(gspca_dev, 0x78, 0x00);
}

/* called on streamoff with alt 0 and on disconnect for pac7302 */
static void sd_stop0(struct gspca_dev *gspca_dev)
{
        if (!gspca_dev->present)
                return;
        reg_w(gspca_dev, 0xff, 0x01);
        reg_w(gspca_dev, 0x78, 0x40);
}

static void do_autogain(struct gspca_dev *gspca_dev)
{
        struct sd *sd = (struct sd *) gspca_dev;
        int avg_lum = atomic_read(&sd->avg_lum);
        int desired_lum;
        const int deadzone = 30;

        if (sd->autogain_ignore_frames < 0)
                return;

        if (sd->autogain_ignore_frames > 0) {
                sd->autogain_ignore_frames--;
        } else {
                desired_lum = 270 + sd->brightness->val;

                if (gspca_expo_autogain(gspca_dev, avg_lum, desired_lum,
                                        deadzone, PAC7302_GAIN_KNEE,
                                        PAC7302_EXPOSURE_KNEE))
                        sd->autogain_ignore_frames =
                                                PAC_AUTOGAIN_IGNORE_FRAMES;
        }
}

/* JPEG header */
static const u8 jpeg_header[] = {
        0xff, 0xd8,     /* SOI: Start of Image */

        0xff, 0xc0,     /* SOF0: Start of Frame (Baseline DCT) */
        0x00, 0x11,     /* length = 17 bytes (including this length field) */
        0x08,           /* Precision: 8 */
        0x02, 0x80,     /* height = 640 (image rotated) */
        0x01, 0xe0,     /* width = 480 */
        0x03,           /* Number of image components: 3 */
        0x01, 0x21, 0x00, /* ID=1, Subsampling 1x1, Quantization table: 0 */
        0x02, 0x11, 0x01, /* ID=2, Subsampling 2x1, Quantization table: 1 */
        0x03, 0x11, 0x01, /* ID=3, Subsampling 2x1, Quantization table: 1 */

        0xff, 0xda,     /* SOS: Start Of Scan */
        0x00, 0x0c,     /* length = 12 bytes (including this length field) */
        0x03,           /* number of components: 3 */
        0x01, 0x00,     /* selector 1, table 0x00 */
        0x02, 0x11,     /* selector 2, table 0x11 */
        0x03, 0x11,     /* selector 3, table 0x11 */
        0x00, 0x3f,     /* Spectral selection: 0 .. 63 */
        0x00            /* Successive approximation: 0 */
};

/* this function is run at interrupt level */
static void sd_pkt_scan(struct gspca_dev *gspca_dev,
                        u8 *data,                       /* isoc packet */
                        int len)                        /* iso packet length */
{
        struct sd *sd = (struct sd *) gspca_dev;
        u8 *image;
        u8 *sof;

        sof = pac_find_sof(gspca_dev, &sd->sof_read, data, len);
        if (sof) {
                int n, lum_offset, footer_length;

                /*
                 * 6 bytes after the FF D9 EOF marker a number of lumination
                 * bytes are send corresponding to different parts of the
                 * image, the 14th and 15th byte after the EOF seem to
                 * correspond to the center of the image.
                 */
                lum_offset = 61 + sizeof pac_sof_marker;
                footer_length = 74;

                /* Finish decoding current frame */
                n = (sof - data) - (footer_length + sizeof pac_sof_marker);
                if (n < 0) {
                        gspca_dev->image_len += n;
                        n = 0;
                } else {
                        gspca_frame_add(gspca_dev, INTER_PACKET, data, n);
                }

                image = gspca_dev->image;
                if (image != NULL
                 && image[gspca_dev->image_len - 2] == 0xff
                 && image[gspca_dev->image_len - 1] == 0xd9)
                        gspca_frame_add(gspca_dev, LAST_PACKET, NULL, 0);

                n = sof - data;
                len -= n;
                data = sof;

                /* Get average lumination */
                if (gspca_dev->last_packet_type == LAST_PACKET &&
                                n >= lum_offset)
                        atomic_set(&sd->avg_lum, data[-lum_offset] +
                                                data[-lum_offset + 1]);

                /* Start the new frame with the jpeg header */
                /* The PAC7302 has the image rotated 90 degrees */
                gspca_frame_add(gspca_dev, FIRST_PACKET,
                                jpeg_header, sizeof jpeg_header);
        }
        gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int sd_dbg_s_register(struct gspca_dev *gspca_dev,
                        const struct v4l2_dbg_register *reg)
{
        u8 index;
        u8 value;

        /*
         * reg->reg: bit0..15: reserved for register index (wIndex is 16bit
         *                     long on the USB bus)
         */
        if (reg->match.type == V4L2_CHIP_MATCH_HOST &&
            reg->match.addr == 0 &&
            (reg->reg < 0x000000ff) &&
            (reg->val <= 0x000000ff)
        ) {
                /* Currently writing to page 0 is only supported. */
                /* reg_w() only supports 8bit index */
                index = reg->reg;
                value = reg->val;

                /*
                 * Note that there shall be no access to other page
                 * by any other function between the page switch and
                 * the actual register write.
                 */
                reg_w(gspca_dev, 0xff, 0x00);           /* page 0 */
                reg_w(gspca_dev, index, value);

                reg_w(gspca_dev, 0xdc, 0x01);
        }
        return gspca_dev->usb_err;
}

static int sd_chip_ident(struct gspca_dev *gspca_dev,
                        struct v4l2_dbg_chip_ident *chip)
{
        int ret = -EINVAL;

        if (chip->match.type == V4L2_CHIP_MATCH_HOST &&
            chip->match.addr == 0) {
                chip->revision = 0;
                chip->ident = V4L2_IDENT_UNKNOWN;
                ret = 0;
        }
        return ret;
}
#endif

#if IS_ENABLED(CONFIG_INPUT)
static int sd_int_pkt_scan(struct gspca_dev *gspca_dev,
                        u8 *data,               /* interrupt packet data */
                        int len)                /* interrput packet length */
{
        int ret = -EINVAL;
        u8 data0, data1;

        if (len == 2) {
                data0 = data[0];
                data1 = data[1];
                if ((data0 == 0x00 && data1 == 0x11) ||
                    (data0 == 0x22 && data1 == 0x33) ||
                    (data0 == 0x44 && data1 == 0x55) ||
                    (data0 == 0x66 && data1 == 0x77) ||
                    (data0 == 0x88 && data1 == 0x99) ||
                    (data0 == 0xaa && data1 == 0xbb) ||
                    (data0 == 0xcc && data1 == 0xdd) ||
                    (data0 == 0xee && data1 == 0xff)) {
                        input_report_key(gspca_dev->input_dev, KEY_CAMERA, 1);
                        input_sync(gspca_dev->input_dev);
                        input_report_key(gspca_dev->input_dev, KEY_CAMERA, 0);
                        input_sync(gspca_dev->input_dev);
                        ret = 0;
                }
        }

        return ret;
}
#endif

/* sub-driver description for pac7302 */
static const struct sd_desc sd_desc = {
        .name = KBUILD_MODNAME,
        .config = sd_config,
        .init = sd_init,
        .init_controls = sd_init_controls,
        .start = sd_start,
        .stopN = sd_stopN,
        .stop0 = sd_stop0,
        .pkt_scan = sd_pkt_scan,
        .dq_callback = do_autogain,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .set_register = sd_dbg_s_register,
        .get_chip_ident = sd_chip_ident,
#endif
#if IS_ENABLED(CONFIG_INPUT)
        .int_pkt_scan = sd_int_pkt_scan,
#endif
};

/* -- module initialisation -- */
static const struct usb_device_id device_table[] = {
        {USB_DEVICE(0x06f8, 0x3009)},
        {USB_DEVICE(0x06f8, 0x301b)},
        {USB_DEVICE(0x093a, 0x2620)},
        {USB_DEVICE(0x093a, 0x2621)},
        {USB_DEVICE(0x093a, 0x2622), .driver_info = FL_VFLIP},
        {USB_DEVICE(0x093a, 0x2624), .driver_info = FL_VFLIP},
        {USB_DEVICE(0x093a, 0x2625)},
        {USB_DEVICE(0x093a, 0x2626)},
        {USB_DEVICE(0x093a, 0x2627), .driver_info = FL_VFLIP},
        {USB_DEVICE(0x093a, 0x2628)},
        {USB_DEVICE(0x093a, 0x2629), .driver_info = FL_VFLIP},
        {USB_DEVICE(0x093a, 0x262a)},
        {USB_DEVICE(0x093a, 0x262c)},
        {USB_DEVICE(0x145f, 0x013c)},
        {USB_DEVICE(0x1ae7, 0x2001)}, /* SpeedLink Snappy Mic SL-6825-SBK */
        {}
};
MODULE_DEVICE_TABLE(usb, device_table);

/* -- device connect -- */
static int sd_probe(struct usb_interface *intf,
                        const struct usb_device_id *id)
{
        return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
                                THIS_MODULE);
}

static struct usb_driver sd_driver = {
        .name = KBUILD_MODNAME,
        .id_table = device_table,
        .probe = sd_probe,
        .disconnect = gspca_disconnect,
#ifdef CONFIG_PM
        .suspend = gspca_suspend,
        .resume = gspca_resume,
        .reset_resume = gspca_resume,
#endif
};

module_usb_driver(sd_driver);