/*
 *              Pixart PAC7311 library
 *              Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li
 *
 * V4L2 by Jean-Francois Moine <http://moinejf.free.fr>
 *
 * 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.
 */

/* Some documentation about various registers as determined by trial and error.
 *
 * Register page 1:
 *
 * Address      Description
 * 0x08         Unknown compressor related, must always be 8 except when not
 *              in 640x480 resolution and page 4 reg 2 <= 3 then set it to 9 !
 * 0x1b         Auto white balance related, bit 0 is AWB enable (inverted)
 *              bits 345 seem to toggle per color gains on/off (inverted)
 * 0x78         Global control, bit 6 controls the LED (inverted)
 * 0x80         Compression balance, interesting settings:
 *              0x01 Use this to allow the camera to switch to higher compr.
 *                   on the fly. Needed to stay within bandwidth @ 640x480@30
 *              0x1c From usb captures under Windows for 640x480
 *              0x2a Values >= this switch the camera to a lower compression,
 *                   using the same table for both luminance and chrominance.
 *                   This gives a sharper picture. Usable only at 640x480@ <
 *                   15 fps or 320x240 / 160x120. 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
 *              0x3f From usb captures under Windows for 320x240
 *              0x69 From usb captures under Windows for 160x120
 *
 * Register page 4:
 *
 * Address      Description
 * 0x02         Clock divider 2-63, fps =~ 60 / val. Must be a multiple of 3 on
 *              the 7302, so one of 3, 6, 9, ..., except when between 6 and 12?
 * 0x0f         Master gain 1-245, low value = high gain
 * 0x10         Another gain 0-15, limited influence (1-2x gain I guess)
 * 0x21         Bitfield: 0-1 unused, 2-3 vflip/hflip, 4-5 unknown, 6-7 unused
 *              Note setting vflip disabled leads to a much lower image quality,
 *              so we always vflip, and tell userspace to flip it back
 * 0x27         Seems to toggle various gains on / off, Setting bit 7 seems to
 *              completely disable the analog amplification block. Set to 0x68
 *              for max gain, 0x14 for minimal gain.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#define MODULE_NAME "pac7311"

#include <linux/input.h>
#include "gspca.h"
/* Include pac common sof detection functions */
#include "pac_common.h"

#define PAC7311_GAIN_DEFAULT     122
#define PAC7311_EXPOSURE_DEFAULT   3 /* 20 fps, avoid using high compr. */

MODULE_AUTHOR("Thomas Kaiser thomas@kaiser-linux.li");
MODULE_DESCRIPTION("Pixart PAC7311");
MODULE_LICENSE("GPL");

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

        struct v4l2_ctrl *contrast;
        struct v4l2_ctrl *hflip;

        u8 sof_read;
        u8 autogain_ignore_frames;

        atomic_t avg_lum;
};

static const struct v4l2_pix_format vga_mode[] = {
        {160, 120, V4L2_PIX_FMT_PJPG, V4L2_FIELD_NONE,
                .bytesperline = 160,
                .sizeimage = 160 * 120 * 3 / 8 + 590,
                .colorspace = V4L2_COLORSPACE_JPEG,
                .priv = 2},
        {320, 240, V4L2_PIX_FMT_PJPG, V4L2_FIELD_NONE,
                .bytesperline = 320,
                .sizeimage = 320 * 240 * 3 / 8 + 590,
                .colorspace = V4L2_COLORSPACE_JPEG,
                .priv = 1},
        {640, 480, V4L2_PIX_FMT_PJPG, V4L2_FIELD_NONE,
                .bytesperline = 640,
                .sizeimage = 640 * 480 * 3 / 8 + 590,
                .colorspace = V4L2_COLORSPACE_JPEG,
                .priv = 0},
};

#define LOAD_PAGE4              254
#define END_OF_SEQUENCE         0

static const __u8 init_7311[] = {
        0xff, 0x01,
        0x78, 0x40,     /* Bit_0=start stream, Bit_6=LED */
        0x78, 0x40,     /* Bit_0=start stream, Bit_6=LED */
        0x78, 0x44,     /* Bit_0=start stream, Bit_6=LED */
        0xff, 0x04,
        0x27, 0x80,
        0x28, 0xca,
        0x29, 0x53,
        0x2a, 0x0e,
        0xff, 0x01,
        0x3e, 0x20,
};

static const __u8 start_7311[] = {
/*      index, len, [value]* */
        0xff, 1,        0x01,           /* page 1 */
        0x02, 43,       0x48, 0x0a, 0x40, 0x08, 0x00, 0x00, 0x08, 0x00,
                        0x06, 0xff, 0x11, 0xff, 0x5a, 0x30, 0x90, 0x4c,
                        0x00, 0x07, 0x00, 0x0a, 0x10, 0x00, 0xa0, 0x10,
                        0x02, 0x00, 0x00, 0x00, 0x00, 0x0b, 0x01, 0x00,
                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                        0x00, 0x00, 0x00,
        0x3e, 42,       0x00, 0x00, 0x78, 0x52, 0x4a, 0x52, 0x78, 0x6e,
                        0x48, 0x46, 0x48, 0x6e, 0x5f, 0x49, 0x42, 0x49,
                        0x5f, 0x5f, 0x49, 0x42, 0x49, 0x5f, 0x6e, 0x48,
                        0x46, 0x48, 0x6e, 0x78, 0x52, 0x4a, 0x52, 0x78,
                        0x00, 0x00, 0x09, 0x1b, 0x34, 0x49, 0x5c, 0x9b,
                        0xd0, 0xff,
        0x78, 6,        0x44, 0x00, 0xf2, 0x01, 0x01, 0x80,
        0x7f, 18,       0x2a, 0x1c, 0x00, 0xc8, 0x02, 0x58, 0x03, 0x84,
                        0x12, 0x00, 0x1a, 0x04, 0x08, 0x0c, 0x10, 0x14,
                        0x18, 0x20,
        0x96, 3,        0x01, 0x08, 0x04,
        0xa0, 4,        0x44, 0x44, 0x44, 0x04,
        0xf0, 13,       0x01, 0x00, 0x00, 0x00, 0x22, 0x00, 0x20, 0x00,
                        0x3f, 0x00, 0x0a, 0x01, 0x00,
        0xff, 1,        0x04,           /* page 4 */
        0, LOAD_PAGE4,                  /* load the page 4 */
        0x11, 1,        0x01,
        0, END_OF_SEQUENCE              /* end of sequence */
};

#define SKIP            0xaa
/* page 4 - the value SKIP says skip the index - see reg_w_page() */
static const __u8 page4_7311[] = {
        SKIP, SKIP, 0x04, 0x54, 0x07, 0x2b, 0x09, 0x0f,
        0x09, 0x00, SKIP, SKIP, 0x07, 0x00, 0x00, 0x62,
        0x08, SKIP, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x03, 0xa0, 0x01, 0xf4, SKIP,
        SKIP, 0x00, 0x08, SKIP, 0x03, SKIP, 0x00, 0x68,
        0xca, 0x10, 0x06, 0x78, 0x00, 0x00, 0x00, 0x00,
        0x23, 0x28, 0x04, 0x11, 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 index 0x%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 index 0x%02x, value 0x%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 index 0x%02x, value 0x%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 *page4, unsigned int page4_len)
{
        int index, len;

        for (;;) {
                index = *seq++;
                len = *seq++;
                switch (len) {
                case END_OF_SEQUENCE:
                        return;
                case LOAD_PAGE4:
                        reg_w_page(gspca_dev, page4, page4_len);
                        break;
                default:
                        if (len > USB_BUF_SZ) {
                                gspca_err(gspca_dev, "Incorrect variable sequence\n");
                                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 pac7311 */
static int sd_config(struct gspca_dev *gspca_dev,
                        const struct usb_device_id *id)
{
        struct cam *cam = &gspca_dev->cam;

        cam->cam_mode = vga_mode;
        cam->nmodes = ARRAY_SIZE(vga_mode);
        cam->input_flags = V4L2_IN_ST_VFLIP;

        return 0;
}

static void setcontrast(struct gspca_dev *gspca_dev, s32 val)
{
        reg_w(gspca_dev, 0xff, 0x04);
        reg_w(gspca_dev, 0x10, val);
        /* load registers to sensor (Bit 0, auto clear) */
        reg_w(gspca_dev, 0x11, 0x01);
}

static void setgain(struct gspca_dev *gspca_dev, s32 val)
{
        reg_w(gspca_dev, 0xff, 0x04);                   /* page 4 */
        reg_w(gspca_dev, 0x0e, 0x00);
        reg_w(gspca_dev, 0x0f, gspca_dev->gain->maximum - val + 1);

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

static void setexposure(struct gspca_dev *gspca_dev, s32 val)
{
        reg_w(gspca_dev, 0xff, 0x04);                   /* page 4 */
        reg_w(gspca_dev, 0x02, val);

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

        /*
         * Page 1 register 8 must always be 0x08 except when not in
         *  640x480 mode and page 4 reg 2 <= 3 then it must be 9
         */
        reg_w(gspca_dev, 0xff, 0x01);
        if (gspca_dev->pixfmt.width != 640 && val <= 3)
                reg_w(gspca_dev, 0x08, 0x09);
        else
                reg_w(gspca_dev, 0x08, 0x08);

        /*
         * Page1 register 80 sets the compression balance, normally we
         * want / use 0x1c, but for 640x480@30fps we must allow the
         * camera to use higher compression or we may run out of
         * bandwidth.
         */
        if (gspca_dev->pixfmt.width == 640 && val == 2)
                reg_w(gspca_dev, 0x80, 0x01);
        else
                reg_w(gspca_dev, 0x80, 0x1c);

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

static void sethvflip(struct gspca_dev *gspca_dev, s32 hflip, s32 vflip)
{
        __u8 data;

        reg_w(gspca_dev, 0xff, 0x04);                   /* page 4 */
        data = (hflip ? 0x04 : 0x00) |
               (vflip ? 0x08 : 0x00);
        reg_w(gspca_dev, 0x21, data);

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

/* this function is called at probe and resume time for pac7311 */
static int sd_init(struct gspca_dev *gspca_dev)
{
        reg_w_seq(gspca_dev, init_7311, sizeof(init_7311)/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    = PAC7311_EXPOSURE_DEFAULT;
                gspca_dev->gain->val        = PAC7311_GAIN_DEFAULT;
                sd->autogain_ignore_frames  = PAC_AUTOGAIN_IGNORE_FRAMES;
        }

        if (!gspca_dev->streaming)
                return 0;

        switch (ctrl->id) {
        case V4L2_CID_CONTRAST:
                setcontrast(gspca_dev, ctrl->val);
                break;
        case V4L2_CID_AUTOGAIN:
                if (gspca_dev->exposure->is_new || (ctrl->is_new && ctrl->val))
                        setexposure(gspca_dev, gspca_dev->exposure->val);
                if (gspca_dev->gain->is_new || (ctrl->is_new && ctrl->val))
                        setgain(gspca_dev, gspca_dev->gain->val);
                break;
        case V4L2_CID_HFLIP:
                sethvflip(gspca_dev, sd->hflip->val, 1);
                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, 5);

        sd->contrast = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_CONTRAST, 0, 15, 1, 7);
        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, 2, 63, 1,
                                        PAC7311_EXPOSURE_DEFAULT);
        gspca_dev->gain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                                        V4L2_CID_GAIN, 0, 244, 1,
                                        PAC7311_GAIN_DEFAULT);
        sd->hflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
                V4L2_CID_HFLIP, 0, 1, 1, 0);

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

        v4l2_ctrl_auto_cluster(3, &gspca_dev->autogain, 0, false);
        return 0;
}

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

        sd->sof_read = 0;

        reg_w_var(gspca_dev, start_7311,
                page4_7311, sizeof(page4_7311));
        setcontrast(gspca_dev, v4l2_ctrl_g_ctrl(sd->contrast));
        setgain(gspca_dev, v4l2_ctrl_g_ctrl(gspca_dev->gain));
        setexposure(gspca_dev, v4l2_ctrl_g_ctrl(gspca_dev->exposure));
        sethvflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->hflip), 1);

        /* set correct resolution */
        switch (gspca_dev->cam.cam_mode[(int) gspca_dev->curr_mode].priv) {
        case 2:                                 /* 160x120 */
                reg_w(gspca_dev, 0xff, 0x01);
                reg_w(gspca_dev, 0x17, 0x20);
                reg_w(gspca_dev, 0x87, 0x10);
                break;
        case 1:                                 /* 320x240 */
                reg_w(gspca_dev, 0xff, 0x01);
                reg_w(gspca_dev, 0x17, 0x30);
                reg_w(gspca_dev, 0x87, 0x11);
                break;
        case 0:                                 /* 640x480 */
                reg_w(gspca_dev, 0xff, 0x01);
                reg_w(gspca_dev, 0x17, 0x00);
                reg_w(gspca_dev, 0x87, 0x12);
                break;
        }

        sd->sof_read = 0;
        sd->autogain_ignore_frames = 0;
        atomic_set(&sd->avg_lum, -1);

        /* start stream */
        reg_w(gspca_dev, 0xff, 0x01);
        reg_w(gspca_dev, 0x78, 0x05);

        return gspca_dev->usb_err;
}

static void sd_stopN(struct gspca_dev *gspca_dev)
{
        reg_w(gspca_dev, 0xff, 0x04);
        reg_w(gspca_dev, 0x27, 0x80);
        reg_w(gspca_dev, 0x28, 0xca);
        reg_w(gspca_dev, 0x29, 0x53);
        reg_w(gspca_dev, 0x2a, 0x0e);
        reg_w(gspca_dev, 0xff, 0x01);
        reg_w(gspca_dev, 0x3e, 0x20);
        reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_6=LED */
        reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_6=LED */
        reg_w(gspca_dev, 0x78, 0x44); /* Bit_0=start stream, Bit_6=LED */
}

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, deadzone;

        if (avg_lum == -1)
                return;

        desired_lum = 170;
        deadzone = 20;

        if (sd->autogain_ignore_frames > 0)
                sd->autogain_ignore_frames--;
        else if (gspca_coarse_grained_expo_autogain(gspca_dev, avg_lum,
                                                    desired_lum, deadzone))
                sd->autogain_ignore_frames = PAC_AUTOGAIN_IGNORE_FRAMES;
}

/* JPEG header, part 1 */
static const unsigned char pac_jpeg_header1[] = {
  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 */
  /* 2 bytes is placed here: number of image lines */
  /* 2 bytes is placed here: samples per line */
};

/* JPEG header, continued */
static const unsigned char pac_jpeg_header2[] = {
  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 */
};

static void pac_start_frame(struct gspca_dev *gspca_dev,
                __u16 lines, __u16 samples_per_line)
{
        unsigned char tmpbuf[4];

        gspca_frame_add(gspca_dev, FIRST_PACKET,
                pac_jpeg_header1, sizeof(pac_jpeg_header1));

        tmpbuf[0] = lines >> 8;
        tmpbuf[1] = lines & 0xff;
        tmpbuf[2] = samples_per_line >> 8;
        tmpbuf[3] = samples_per_line & 0xff;

        gspca_frame_add(gspca_dev, INTER_PACKET,
                tmpbuf, sizeof(tmpbuf));
        gspca_frame_add(gspca_dev, INTER_PACKET,
                pac_jpeg_header2, sizeof(pac_jpeg_header2));
}

/* 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;
        unsigned char *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 = 24 + sizeof pac_sof_marker;
                footer_length = 26;

                /* 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]);
                else
                        atomic_set(&sd->avg_lum, -1);

                /* Start the new frame with the jpeg header */
                pac_start_frame(gspca_dev,
                        gspca_dev->pixfmt.height, gspca_dev->pixfmt.width);
        }
        gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
}

#if IS_ENABLED(CONFIG_INPUT)
static int sd_int_pkt_scan(struct gspca_dev *gspca_dev,
                        u8 *data,               /* interrupt packet data */
                        int len)                /* interrupt 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

static const struct sd_desc sd_desc = {
        .name = MODULE_NAME,
        .config = sd_config,
        .init = sd_init,
        .init_controls = sd_init_controls,
        .start = sd_start,
        .stopN = sd_stopN,
        .pkt_scan = sd_pkt_scan,
        .dq_callback = do_autogain,
#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(0x093a, 0x2600)},
        {USB_DEVICE(0x093a, 0x2601)},
        {USB_DEVICE(0x093a, 0x2603)},
        {USB_DEVICE(0x093a, 0x2608)},
        {USB_DEVICE(0x093a, 0x260e)},
        {USB_DEVICE(0x093a, 0x260f)},
        {}
};
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 = MODULE_NAME,
        .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);