/*
 * Driver for Logitech Quickcam Messenger usb video camera
 * Copyright (C) Jaya Kumar
 *
 * This work was sponsored by CIS(M) Sdn Bhd.
 * History:
 * 05/08/2006 - Jaya Kumar
 * I wrote this based on the konicawc by Simon Evans.
 * -
 * Full credit for reverse engineering and creating an initial
 * working linux driver for the VV6422 goes to the qce-ga project by
 * Tuukka Toivonen, Jochen Hoenicke, Peter McConnell,
 * Cristiano De Michele, Georg Acher, Jean-Frederic Clere as well as
 * others.
 * ---
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/usb/input.h>

#include "usbvideo.h"
#include "quickcam_messenger.h"

/*
 * Version Information
 */

#ifdef CONFIG_USB_DEBUG
static int debug;
#define DEBUG(n, format, arg...) \
        if (n <= debug) {        \
                printk(KERN_DEBUG __FILE__ ":%s(): " format "\n", __func__ , ## arg); \
        }
#else
#define DEBUG(n, arg...)
static const int debug;
#endif

#define DRIVER_VERSION "v0.01"
#define DRIVER_DESC "Logitech Quickcam Messenger USB"

#define USB_LOGITECH_VENDOR_ID  0x046D
#define USB_QCM_PRODUCT_ID      0x08F0

#define MAX_CAMERAS     1

#define MAX_COLOUR      32768
#define MAX_HUE         32768
#define MAX_BRIGHTNESS  32768
#define MAX_CONTRAST    32768
#define MAX_WHITENESS   32768

static int size = SIZE_320X240;
static int colour = MAX_COLOUR;
static int hue = MAX_HUE;
static int brightness = MAX_BRIGHTNESS;
static int contrast =   MAX_CONTRAST;
static int whiteness =  MAX_WHITENESS;

static struct usbvideo *cams;

static struct usb_device_id qcm_table [] = {
        { USB_DEVICE(USB_LOGITECH_VENDOR_ID, USB_QCM_PRODUCT_ID) },
        { }
};
MODULE_DEVICE_TABLE(usb, qcm_table);

#ifdef CONFIG_INPUT
static void qcm_register_input(struct qcm *cam, struct usb_device *dev)
{
        struct input_dev *input_dev;
        int error;

        usb_make_path(dev, cam->input_physname, sizeof(cam->input_physname));
        strncat(cam->input_physname, "/input0", sizeof(cam->input_physname));

        cam->input = input_dev = input_allocate_device();
        if (!input_dev) {
                dev_warn(&dev->dev, "insufficient mem for cam input device\n");
                return;
        }

        input_dev->name = "QCM button";
        input_dev->phys = cam->input_physname;
        usb_to_input_id(dev, &input_dev->id);
        input_dev->dev.parent = &dev->dev;

        input_dev->evbit[0] = BIT_MASK(EV_KEY);
        input_dev->keybit[BIT_WORD(KEY_CAMERA)] = BIT_MASK(KEY_CAMERA);

        error = input_register_device(cam->input);
        if (error) {
                dev_warn(&dev->dev,
                         "Failed to register camera's input device, err: %d\n",
                         error);
                input_free_device(cam->input);
                cam->input = NULL;
        }
}

static void qcm_unregister_input(struct qcm *cam)
{
        if (cam->input) {
                input_unregister_device(cam->input);
                cam->input = NULL;
        }
}

static void qcm_report_buttonstat(struct qcm *cam)
{
        if (cam->input) {
                input_report_key(cam->input, KEY_CAMERA, cam->button_sts);
                input_sync(cam->input);
        }
}

static void qcm_int_irq(struct urb *urb)
{
        int ret;
        struct uvd *uvd = urb->context;
        struct qcm *cam;

        if (!CAMERA_IS_OPERATIONAL(uvd))
                return;

        if (!uvd->streaming)
                return;

        uvd->stats.urb_count++;

        if (urb->status < 0)
                uvd->stats.iso_err_count++;
        else {
                if (urb->actual_length > 0 ) {
                        cam = (struct qcm *) uvd->user_data;
                        if (cam->button_sts_buf == 0x88)
                                cam->button_sts = 0x0;
                        else if (cam->button_sts_buf == 0x80)
                                cam->button_sts = 0x1;
                        qcm_report_buttonstat(cam);
                }
        }

        ret = usb_submit_urb(urb, GFP_ATOMIC);
        if (ret < 0)
                err("usb_submit_urb error (%d)", ret);
}

static int qcm_setup_input_int(struct qcm *cam, struct uvd *uvd)
{
        int errflag;
        usb_fill_int_urb(cam->button_urb, uvd->dev,
                        usb_rcvintpipe(uvd->dev, uvd->video_endp + 1),
                        &cam->button_sts_buf,
                        1,
                        qcm_int_irq,
                        uvd, 16);

        errflag = usb_submit_urb(cam->button_urb, GFP_KERNEL);
        if (errflag)
                err ("usb_submit_int ret %d", errflag);
        return errflag;
}

static void qcm_stop_int_data(struct qcm *cam)
{
        usb_kill_urb(cam->button_urb);
}

static int qcm_alloc_int_urb(struct qcm *cam)
{
        cam->button_urb = usb_alloc_urb(0, GFP_KERNEL);

        if (!cam->button_urb)
                return -ENOMEM;

        return 0;
}

static void qcm_free_int(struct qcm *cam)
{
        usb_free_urb(cam->button_urb);
}
#endif /* CONFIG_INPUT */

static int qcm_stv_setb(struct usb_device *dev, u16 reg, u8 val)
{
        int ret;

        /* we'll wait up to 3 slices but no more */
        ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                0x04, USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                reg, 0, &val, 1, 3*HZ);
        return ret;
}

static int qcm_stv_setw(struct usb_device *dev, u16 reg, __le16 val)
{
        int ret;

        /* we'll wait up to 3 slices but no more */
        ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                0x04, USB_TYPE_VENDOR | USB_DIR_OUT | USB_RECIP_DEVICE,
                reg, 0, &val, 2, 3*HZ);
        return ret;
}

static int qcm_stv_getw(struct usb_device *dev, unsigned short reg,
                                                        __le16 *val)
{
        int ret;

        /* we'll wait up to 3 slices but no more */
        ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
                0x04, USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
                reg, 0, val, 2, 3*HZ);
        return ret;
}

static int qcm_camera_on(struct uvd *uvd)
{
        int ret;
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, STV_ISO_ENABLE, 0x01));
        return 0;
}

static int qcm_camera_off(struct uvd *uvd)
{
        int ret;
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, STV_ISO_ENABLE, 0x00));
        return 0;
}

static void qcm_hsv2rgb(u16 hue, u16 sat, u16 val, u16 *r, u16 *g, u16 *b)
{
        unsigned int segment, valsat;
        signed int   h = (signed int) hue;
        unsigned int s = (sat - 32768) * 2;     /* rescale */
        unsigned int v = val;
        unsigned int p;

        /*
        the registers controlling gain are 8 bit of which
        we affect only the last 4 bits with our gain.
        we know that if saturation is 0, (unsaturated) then
        we're grayscale (center axis of the colour cone) so
        we set rgb=value. we use a formula obtained from
        wikipedia to map the cone to the RGB plane. it's
        as follows for the human value case of h=0..360,
        s=0..1, v=0..1
        h_i = h/60 % 6 , f = h/60 - h_i , p = v(1-s)
        q = v(1 - f*s) , t = v(1 - (1-f)s)
        h_i==0 => r=v , g=t, b=p
        h_i==1 => r=q , g=v, b=p
        h_i==2 => r=p , g=v, b=t
        h_i==3 => r=p , g=q, b=v
        h_i==4 => r=t , g=p, b=v
        h_i==5 => r=v , g=p, b=q
        the bottom side (the point) and the stuff just up
        of that is black so we simplify those two cases.
        */
        if (sat < 32768) {
                /* anything less than this is unsaturated */
                *r = val;
                *g = val;
                *b = val;
                return;
        }
        if (val <= (0xFFFF/8)) {
                /* anything less than this is black */
                *r = 0;
                *g = 0;
                *b = 0;
                return;
        }

        /* the rest of this code is copying tukkat's
        implementation of the hsv2rgb conversion as taken
        from qc-usb-messenger code. the 10923 is 0xFFFF/6
        to divide the cone into 6 sectors.  */

        segment = (h + 10923) & 0xFFFF;
        segment = segment*3 >> 16;              /* 0..2: 0=R, 1=G, 2=B */
        hue -= segment * 21845;                 /* -10923..10923 */
        h = hue;
        h *= 3;
        valsat = v*s >> 16;                     /* 0..65534 */
        p = v - valsat;
        if (h >= 0) {
                unsigned int t = v - (valsat * (32769 - h) >> 15);
                switch (segment) {
                case 0: /* R-> */
                        *r = v;
                        *g = t;
                        *b = p;
                        break;
                case 1: /* G-> */
                        *r = p;
                        *g = v;
                        *b = t;
                        break;
                case 2: /* B-> */
                        *r = t;
                        *g = p;
                        *b = v;
                        break;
                }
        } else {
                unsigned int q = v - (valsat * (32769 + h) >> 15);
                switch (segment) {
                case 0: /* ->R */
                        *r = v;
                        *g = p;
                        *b = q;
                        break;
                case 1: /* ->G */
                        *r = q;
                        *g = v;
                        *b = p;
                        break;
                case 2: /* ->B */
                        *r = p;
                        *g = q;
                        *b = v;
                        break;
                }
        }
}

static int qcm_sensor_set_gains(struct uvd *uvd, u16 hue,
        u16 saturation, u16 value)
{
        int ret;
        u16 r=0,g=0,b=0;

        /* this code is based on qc-usb-messenger */
        qcm_hsv2rgb(hue, saturation, value, &r, &g, &b);

        r >>= 12;
        g >>= 12;
        b >>= 12;

        /* min val is 8 */
        r = max((u16) 8, r);
        g = max((u16) 8, g);
        b = max((u16) 8, b);

        r |= 0x30;
        g |= 0x30;
        b |= 0x30;

        /* set the r,g,b gain registers */
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x0509, r));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x050A, g));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x050B, b));

        /* doing as qc-usb did */
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x050C, 0x2A));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x050D, 0x01));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x143F, 0x01));

        return 0;
}

static int qcm_sensor_set_exposure(struct uvd *uvd, int exposure)
{
        int ret;
        int formedval;

        /* calculation was from qc-usb-messenger driver */
        formedval = ( exposure >> 12 );

        /* max value for formedval is 14 */
        formedval = min(formedval, 14);

        CHECK_RET(ret, qcm_stv_setb(uvd->dev,
                        0x143A, 0xF0 | formedval));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x143F, 0x01));
        return 0;
}

static int qcm_sensor_setlevels(struct uvd *uvd, int brightness, int contrast,
                                        int hue, int colour)
{
        int ret;
        /* brightness is exposure, contrast is gain, colour is saturation */
        CHECK_RET(ret,
                qcm_sensor_set_exposure(uvd, brightness));
        CHECK_RET(ret, qcm_sensor_set_gains(uvd, hue, colour, contrast));

        return 0;
}

static int qcm_sensor_setsize(struct uvd *uvd, u8 size)
{
        int ret;

        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x1505, size));
        return 0;
}

static int qcm_sensor_set_shutter(struct uvd *uvd, int whiteness)
{
        int ret;
        /* some rescaling as done by the qc-usb-messenger code */
        if (whiteness > 0xC000)
                whiteness = 0xC000 + (whiteness & 0x3FFF)*8;

        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x143D,
                                (whiteness >> 8) & 0xFF));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x143E,
                                (whiteness >> 16) & 0x03));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x143F, 0x01));

        return 0;
}

static int qcm_sensor_init(struct uvd *uvd)
{
        struct qcm *cam = (struct qcm *) uvd->user_data;
        int ret;
        int i;

        for (i=0; i < ARRAY_SIZE(regval_table) ; i++) {
                CHECK_RET(ret, qcm_stv_setb(uvd->dev,
                                        regval_table[i].reg,
                                        regval_table[i].val));
        }

        CHECK_RET(ret, qcm_stv_setw(uvd->dev, 0x15c1,
                                cpu_to_le16(ISOC_PACKET_SIZE)));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x15c3, 0x08));
        CHECK_RET(ret, qcm_stv_setb(uvd->dev, 0x143f, 0x01));

        CHECK_RET(ret, qcm_stv_setb(uvd->dev, STV_ISO_ENABLE, 0x00));

        CHECK_RET(ret, qcm_sensor_setsize(uvd, camera_sizes[cam->size].cmd));

        CHECK_RET(ret, qcm_sensor_setlevels(uvd, uvd->vpic.brightness,
                        uvd->vpic.contrast, uvd->vpic.hue, uvd->vpic.colour));

        CHECK_RET(ret, qcm_sensor_set_shutter(uvd, uvd->vpic.whiteness));
        CHECK_RET(ret, qcm_sensor_setsize(uvd, camera_sizes[cam->size].cmd));

        return 0;
}

static int qcm_set_camera_size(struct uvd *uvd)
{
        int ret;
        struct qcm *cam = (struct qcm *) uvd->user_data;

        CHECK_RET(ret, qcm_sensor_setsize(uvd, camera_sizes[cam->size].cmd));
        cam->width = camera_sizes[cam->size].width;
        cam->height = camera_sizes[cam->size].height;
        uvd->videosize = VIDEOSIZE(cam->width, cam->height);

        return 0;
}

static int qcm_setup_on_open(struct uvd *uvd)
{
        int ret;

        CHECK_RET(ret, qcm_sensor_set_gains(uvd, uvd->vpic.hue,
                                uvd->vpic.colour, uvd->vpic.contrast));
        CHECK_RET(ret, qcm_sensor_set_exposure(uvd, uvd->vpic.brightness));
        CHECK_RET(ret, qcm_sensor_set_shutter(uvd, uvd->vpic.whiteness));
        CHECK_RET(ret, qcm_set_camera_size(uvd));
        CHECK_RET(ret, qcm_camera_on(uvd));
        return 0;
}

static void qcm_adjust_picture(struct uvd *uvd)
{
        int ret;
        struct qcm *cam = (struct qcm *) uvd->user_data;

        ret = qcm_camera_off(uvd);
        if (ret) {
                err("can't turn camera off. abandoning pic adjustment");
                return;
        }

        /* if there's been a change in contrast, hue, or
        colour then we need to recalculate hsv in order
        to update gains */
        if ((cam->contrast != uvd->vpic.contrast) ||
                (cam->hue != uvd->vpic.hue) ||
                (cam->colour != uvd->vpic.colour)) {
                cam->contrast = uvd->vpic.contrast;
                cam->hue = uvd->vpic.hue;
                cam->colour = uvd->vpic.colour;
                ret = qcm_sensor_set_gains(uvd, cam->hue, cam->colour,
                                                cam->contrast);
                if (ret) {
                        err("can't set gains. abandoning pic adjustment");
                        return;
                }
        }

        if (cam->brightness != uvd->vpic.brightness) {
                cam->brightness = uvd->vpic.brightness;
                ret = qcm_sensor_set_exposure(uvd, cam->brightness);
                if (ret) {
                        err("can't set exposure. abandoning pic adjustment");
                        return;
                }
        }

        if (cam->whiteness != uvd->vpic.whiteness) {
                cam->whiteness = uvd->vpic.whiteness;
                qcm_sensor_set_shutter(uvd, cam->whiteness);
                if (ret) {
                        err("can't set shutter. abandoning pic adjustment");
                        return;
                }
        }

        ret = qcm_camera_on(uvd);
        if (ret) {
                err("can't reenable camera. pic adjustment failed");
                return;
        }
}

static int qcm_process_frame(struct uvd *uvd, u8 *cdata, int framelen)
{
        int datalen;
        int totaldata;
        struct framehdr {
                __be16 id;
                __be16 len;
        };
        struct framehdr *fhdr;

        totaldata = 0;
        while (framelen) {
                fhdr = (struct framehdr *) cdata;
                datalen = be16_to_cpu(fhdr->len);
                framelen -= 4;
                cdata += 4;

                if ((fhdr->id) == cpu_to_be16(0x8001)) {
                        RingQueue_Enqueue(&uvd->dp, marker, 4);
                        totaldata += 4;
                        continue;
                }
                if ((fhdr->id & cpu_to_be16(0xFF00)) == cpu_to_be16(0x0200)) {
                        RingQueue_Enqueue(&uvd->dp, cdata, datalen);
                        totaldata += datalen;
                }
                framelen -= datalen;
                cdata += datalen;
        }
        return totaldata;
}

static int qcm_compress_iso(struct uvd *uvd, struct urb *dataurb)
{
        int totlen;
        int i;
        unsigned char *cdata;

        totlen=0;
        for (i = 0; i < dataurb->number_of_packets; i++) {
                int n = dataurb->iso_frame_desc[i].actual_length;
                int st = dataurb->iso_frame_desc[i].status;

                cdata = dataurb->transfer_buffer +
                        dataurb->iso_frame_desc[i].offset;

                if (st < 0) {
                        dev_warn(&uvd->dev->dev,
                                 "Data error: packet=%d. len=%d. status=%d.\n",
                                 i, n, st);
                        uvd->stats.iso_err_count++;
                        continue;
                }
                if (!n)
                        continue;

                totlen += qcm_process_frame(uvd, cdata, n);
        }
        return totlen;
}

static void resubmit_urb(struct uvd *uvd, struct urb *urb)
{
        int ret;

        urb->dev = uvd->dev;
        ret = usb_submit_urb(urb, GFP_ATOMIC);
        if (ret)
                err("usb_submit_urb error (%d)", ret);
}

static void qcm_isoc_irq(struct urb *urb)
{
        int len;
        struct uvd *uvd = urb->context;

        if (!CAMERA_IS_OPERATIONAL(uvd))
                return;

        if (!uvd->streaming)
                return;

        uvd->stats.urb_count++;

        if (!urb->actual_length) {
                resubmit_urb(uvd, urb);
                return;
        }

        len = qcm_compress_iso(uvd, urb);
        resubmit_urb(uvd, urb);
        uvd->stats.urb_length = len;
        uvd->stats.data_count += len;
        if (len)
                RingQueue_WakeUpInterruptible(&uvd->dp);
}

static int qcm_start_data(struct uvd *uvd)
{
        struct qcm *cam = (struct qcm *) uvd->user_data;
        int i;
        int errflag;
        int pktsz;
        int err;

        pktsz = uvd->iso_packet_len;
        if (!CAMERA_IS_OPERATIONAL(uvd)) {
                err("Camera is not operational");
                return -EFAULT;
        }

        err = usb_set_interface(uvd->dev, uvd->iface, uvd->ifaceAltActive);
        if (err < 0) {
                err("usb_set_interface error");
                uvd->last_error = err;
                return -EBUSY;
        }

        for (i=0; i < USBVIDEO_NUMSBUF; i++) {
                int j, k;
                struct urb *urb = uvd->sbuf[i].urb;
                urb->dev = uvd->dev;
                urb->context = uvd;
                urb->pipe = usb_rcvisocpipe(uvd->dev, uvd->video_endp);
                urb->interval = 1;
                urb->transfer_flags = URB_ISO_ASAP;
                urb->transfer_buffer = uvd->sbuf[i].data;
                urb->complete = qcm_isoc_irq;
                urb->number_of_packets = FRAMES_PER_DESC;
                urb->transfer_buffer_length = pktsz * FRAMES_PER_DESC;
                for (j=k=0; j < FRAMES_PER_DESC; j++, k += pktsz) {
                        urb->iso_frame_desc[j].offset = k;
                        urb->iso_frame_desc[j].length = pktsz;
                }
        }

        uvd->streaming = 1;
        uvd->curframe = -1;
        for (i=0; i < USBVIDEO_NUMSBUF; i++) {
                errflag = usb_submit_urb(uvd->sbuf[i].urb, GFP_KERNEL);
                if (errflag)
                        err ("usb_submit_isoc(%d) ret %d", i, errflag);
        }

        CHECK_RET(err, qcm_setup_input_int(cam, uvd));
        CHECK_RET(err, qcm_camera_on(uvd));
        return 0;
}

static void qcm_stop_data(struct uvd *uvd)
{
        struct qcm *cam = (struct qcm *) uvd->user_data;
        int i, j;
        int ret;

        if ((uvd == NULL) || (!uvd->streaming) || (uvd->dev == NULL))
                return;

        ret = qcm_camera_off(uvd);
        if (ret)
                dev_warn(&uvd->dev->dev, "couldn't turn the cam off.\n");

        uvd->streaming = 0;

        /* Unschedule all of the iso td's */
        for (i=0; i < USBVIDEO_NUMSBUF; i++)
                usb_kill_urb(uvd->sbuf[i].urb);

        qcm_stop_int_data(cam);

        if (!uvd->remove_pending) {
                /* Set packet size to 0 */
                j = usb_set_interface(uvd->dev, uvd->iface,
                                        uvd->ifaceAltInactive);
                if (j < 0) {
                        err("usb_set_interface() error %d.", j);
                        uvd->last_error = j;
                }
        }
}

static void qcm_process_isoc(struct uvd *uvd, struct usbvideo_frame *frame)
{
        struct qcm *cam = (struct qcm *) uvd->user_data;
        int x;
        struct rgb *rgbL0;
        struct rgb *rgbL1;
        struct bayL0 *bayL0;
        struct bayL1 *bayL1;
        int hor,ver,hordel,verdel;
        assert(frame != NULL);

        switch (cam->size) {
        case SIZE_160X120:
                hor = 162; ver = 124; hordel = 1; verdel = 2;
                break;
        case SIZE_320X240:
        default:
                hor = 324; ver = 248; hordel = 2; verdel = 4;
                break;
        }

        if (frame->scanstate == ScanState_Scanning) {
                while (RingQueue_GetLength(&uvd->dp) >=
                         4 + (hor*verdel + hordel)) {
                        if ((RING_QUEUE_PEEK(&uvd->dp, 0) == 0x00) &&
                            (RING_QUEUE_PEEK(&uvd->dp, 1) == 0xff) &&
                            (RING_QUEUE_PEEK(&uvd->dp, 2) == 0x00) &&
                            (RING_QUEUE_PEEK(&uvd->dp, 3) == 0xff)) {
                                frame->curline = 0;
                                frame->scanstate = ScanState_Lines;
                                frame->frameState = FrameState_Grabbing;
                                RING_QUEUE_DEQUEUE_BYTES(&uvd->dp, 4);
                        /*
                        * if we're starting, we need to discard the first
                        * 4 lines of y bayer data
                        * and the first 2 gr elements of x bayer data
                        */
                                RING_QUEUE_DEQUEUE_BYTES(&uvd->dp,
                                                        (hor*verdel + hordel));
                                break;
                        }
                        RING_QUEUE_DEQUEUE_BYTES(&uvd->dp, 1);
                }
        }

        if (frame->scanstate == ScanState_Scanning)
                return;

        /* now we can start processing bayer data so long as we have at least
        * 2 lines worth of data. this is the simplest demosaicing method that
        * I could think of. I use each 2x2 bayer element without interpolation
        * to generate 4 rgb pixels.
        */
        while ( frame->curline < cam->height &&
                (RingQueue_GetLength(&uvd->dp) >= hor*2)) {
                /* get 2 lines of bayer for demosaicing
                 * into 2 lines of RGB */
                RingQueue_Dequeue(&uvd->dp, cam->scratch, hor*2);
                bayL0 = (struct bayL0 *) cam->scratch;
                bayL1 = (struct bayL1 *) (cam->scratch + hor);
                /* frame->curline is the rgb y line */
                rgbL0 = (struct rgb *)
                                ( frame->data + (cam->width*3*frame->curline));
                /* w/2 because we're already doing 2 pixels */
                rgbL1 = rgbL0 + (cam->width/2);

                for (x=0; x < cam->width; x+=2) {
                        rgbL0->r = bayL0->r;
                        rgbL0->g = bayL0->g;
                        rgbL0->b = bayL1->b;

                        rgbL0->r2 = bayL0->r;
                        rgbL0->g2 = bayL1->g;
                        rgbL0->b2 = bayL1->b;

                        rgbL1->r = bayL0->r;
                        rgbL1->g = bayL1->g;
                        rgbL1->b = bayL1->b;

                        rgbL1->r2 = bayL0->r;
                        rgbL1->g2 = bayL1->g;
                        rgbL1->b2 = bayL1->b;

                        rgbL0++;
                        rgbL1++;

                        bayL0++;
                        bayL1++;
                }

                frame->seqRead_Length += cam->width*3*2;
                frame->curline += 2;
        }
        /* See if we filled the frame */
        if (frame->curline == cam->height) {
                frame->frameState = FrameState_Done_Hold;
                frame->curline = 0;
                uvd->curframe = -1;
                uvd->stats.frame_num++;
        }
}

/* taken from konicawc */
static int qcm_set_video_mode(struct uvd *uvd, struct video_window *vw)
{
        int ret;
        int newsize;
        int oldsize;
        int x = vw->width;
        int y = vw->height;
        struct qcm *cam = (struct qcm *) uvd->user_data;

        if (x > 0 && y > 0) {
                DEBUG(2, "trying to find size %d,%d", x, y);
                for (newsize = 0; newsize <= MAX_FRAME_SIZE; newsize++) {
                        if ((camera_sizes[newsize].width == x) &&
                                (camera_sizes[newsize].height == y))
                                break;
                }
        } else
                newsize = cam->size;

        if (newsize > MAX_FRAME_SIZE) {
                DEBUG(1, "couldn't find size %d,%d", x, y);
                return -EINVAL;
        }

        if (newsize == cam->size) {
                DEBUG(1, "Nothing to do");
                return 0;
        }

        qcm_stop_data(uvd);

        if (cam->size != newsize) {
                oldsize = cam->size;
                cam->size = newsize;
                ret = qcm_set_camera_size(uvd);
                if (ret) {
                        err("Couldn't set camera size, err=%d",ret);
                        /* restore the original size */
                        cam->size = oldsize;
                        return ret;
                }
        }

        /* Flush the input queue and clear any current frame in progress */

        RingQueue_Flush(&uvd->dp);
        if (uvd->curframe != -1) {
                uvd->frame[uvd->curframe].curline = 0;
                uvd->frame[uvd->curframe].seqRead_Length = 0;
                uvd->frame[uvd->curframe].seqRead_Index = 0;
        }

        CHECK_RET(ret, qcm_start_data(uvd));
        return 0;
}

static int qcm_configure_video(struct uvd *uvd)
{
        int ret;
        memset(&uvd->vpic, 0, sizeof(uvd->vpic));
        memset(&uvd->vpic_old, 0x55, sizeof(uvd->vpic_old));

        uvd->vpic.colour = colour;
        uvd->vpic.hue = hue;
        uvd->vpic.brightness = brightness;
        uvd->vpic.contrast = contrast;
        uvd->vpic.whiteness = whiteness;
        uvd->vpic.depth = 24;
        uvd->vpic.palette = VIDEO_PALETTE_RGB24;

        memset(&uvd->vcap, 0, sizeof(uvd->vcap));
        strcpy(uvd->vcap.name, "QCM USB Camera");
        uvd->vcap.type = VID_TYPE_CAPTURE;
        uvd->vcap.channels = 1;
        uvd->vcap.audios = 0;

        uvd->vcap.minwidth = camera_sizes[SIZE_160X120].width;
        uvd->vcap.minheight = camera_sizes[SIZE_160X120].height;
        uvd->vcap.maxwidth = camera_sizes[SIZE_320X240].width;
        uvd->vcap.maxheight = camera_sizes[SIZE_320X240].height;

        memset(&uvd->vchan, 0, sizeof(uvd->vchan));
        uvd->vchan.flags = 0 ;
        uvd->vchan.tuners = 0;
        uvd->vchan.channel = 0;
        uvd->vchan.type = VIDEO_TYPE_CAMERA;
        strcpy(uvd->vchan.name, "Camera");

        CHECK_RET(ret, qcm_sensor_init(uvd));
        return 0;
}

static int qcm_probe(struct usb_interface *intf,
                        const struct usb_device_id *devid)
{
        int err;
        struct uvd *uvd;
        struct usb_device *dev = interface_to_usbdev(intf);
        struct qcm *cam;
        size_t buffer_size;
        unsigned char video_ep;
        struct usb_host_interface *interface;
        struct usb_endpoint_descriptor *endpoint;
        int i,j;
        unsigned int ifacenum, ifacenum_inact=0;
        __le16 sensor_id;

        /* we don't support multiconfig cams */
        if (dev->descriptor.bNumConfigurations != 1)
                return -ENODEV;

        /* first check for the video interface and not
        * the audio interface */
        interface = &intf->cur_altsetting[0];
        if ((interface->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
                || (interface->desc.bInterfaceSubClass !=
                        USB_CLASS_VENDOR_SPEC))
                return -ENODEV;

        /*
        walk through each endpoint in each setting in the interface
        stop when we find the one that's an isochronous IN endpoint.
        */
        for (i=0; i < intf->num_altsetting; i++) {
                interface = &intf->cur_altsetting[i];
                ifacenum = interface->desc.bAlternateSetting;
                /* walk the end points */
                for (j=0; j < interface->desc.bNumEndpoints; j++) {
                        endpoint = &interface->endpoint[j].desc;

                        if (usb_endpoint_dir_out(endpoint))
                                continue; /* not input then not good */

                        buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
                        if (!buffer_size) {
                                ifacenum_inact = ifacenum;
                                continue; /* 0 pkt size is not what we want */
                        }

                        if (usb_endpoint_xfer_isoc(endpoint)) {
                                video_ep = endpoint->bEndpointAddress;
                                /* break out of the search */
                                goto good_videoep;
                        }
                }
        }
        /* failed out since nothing useful was found */
        err("No suitable endpoint was found\n");
        return -ENODEV;

good_videoep:
        /* disable isochronous stream before doing anything else */
        err = qcm_stv_setb(dev, STV_ISO_ENABLE, 0);
        if (err < 0) {
                err("Failed to disable sensor stream");
                return -EIO;
        }

        /*
        Check that this is the same unknown sensor that is known to work. This
        sensor is suspected to be the ST VV6422C001. I'll check the same value
        that the qc-usb driver checks. This value is probably not even the
        sensor ID since it matches the USB dev ID. Oh well. If it doesn't
        match, it's probably a diff sensor so exit and apologize.
        */
        err = qcm_stv_getw(dev, CMOS_SENSOR_IDREV, &sensor_id);
        if (err < 0) {
                err("Couldn't read sensor values. Err %d\n",err);
                return err;
        }
        if (sensor_id != cpu_to_le16(0x08F0)) {
                err("Sensor ID %x != %x. Unsupported. Sorry\n",
                        le16_to_cpu(sensor_id), (0x08F0));

                return -ENODEV;
        }

        uvd = usbvideo_AllocateDevice(cams);
        if (!uvd)
                return -ENOMEM;

        cam = (struct qcm *) uvd->user_data;

        /* buf for doing demosaicing */
        cam->scratch = kmalloc(324*2, GFP_KERNEL);
        if (!cam->scratch) /* uvd freed in dereg */
                return -ENOMEM;

        /* yes, if we fail after here, cam->scratch gets freed
        by qcm_free_uvd */

        err = qcm_alloc_int_urb(cam);
        if (err < 0)
                return err;

        /* yes, if we fail after here, int urb gets freed
        by qcm_free_uvd */

        RESTRICT_TO_RANGE(size, SIZE_160X120, SIZE_320X240);
        cam->width = camera_sizes[size].width;
        cam->height = camera_sizes[size].height;
        cam->size = size;

        uvd->debug = debug;
        uvd->flags = 0;
        uvd->dev = dev;
        uvd->iface = intf->altsetting->desc.bInterfaceNumber;
        uvd->ifaceAltActive = ifacenum;
        uvd->ifaceAltInactive = ifacenum_inact;
        uvd->video_endp = video_ep;
        uvd->iso_packet_len = buffer_size;
        uvd->paletteBits = 1L << VIDEO_PALETTE_RGB24;
        uvd->defaultPalette = VIDEO_PALETTE_RGB24;
        uvd->canvas = VIDEOSIZE(320, 240);
        uvd->videosize = VIDEOSIZE(cam->width, cam->height);
        err = qcm_configure_video(uvd);
        if (err) {
                err("failed to configure video settings");
                return err;
        }

        err = usbvideo_RegisterVideoDevice(uvd);
        if (err) { /* the uvd gets freed in Deregister */
                err("usbvideo_RegisterVideoDevice() failed.");
                return err;
        }

        uvd->max_frame_size = (320 * 240 * 3);
        qcm_register_input(cam, dev);
        usb_set_intfdata(intf, uvd);
        return 0;
}

static void qcm_free_uvd(struct uvd *uvd)
{
        struct qcm *cam = (struct qcm *) uvd->user_data;

        kfree(cam->scratch);
        qcm_unregister_input(cam);
        qcm_free_int(cam);
}

static struct usbvideo_cb qcm_driver = {
        .probe =                qcm_probe,
        .setupOnOpen =          qcm_setup_on_open,
        .processData =          qcm_process_isoc,
        .setVideoMode =         qcm_set_video_mode,
        .startDataPump =        qcm_start_data,
        .stopDataPump =         qcm_stop_data,
        .adjustPicture =        qcm_adjust_picture,
        .userFree =             qcm_free_uvd
};

static int __init qcm_init(void)
{
        printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
               DRIVER_DESC "\n");

        return usbvideo_register(
                &cams,
                MAX_CAMERAS,
                sizeof(struct qcm),
                "QCM",
                &qcm_driver,
                THIS_MODULE,
                qcm_table);
}

static void __exit qcm_exit(void)
{
        usbvideo_Deregister(&cams);
}

module_param(size, int, 0);
MODULE_PARM_DESC(size, "Initial Size 0: 160x120 1: 320x240");
module_param(colour, int, 0);
MODULE_PARM_DESC(colour, "Initial colour");
module_param(hue, int, 0);
MODULE_PARM_DESC(hue, "Initial hue");
module_param(brightness, int, 0);
MODULE_PARM_DESC(brightness, "Initial brightness");
module_param(contrast, int, 0);
MODULE_PARM_DESC(contrast, "Initial contrast");
module_param(whiteness, int, 0);
MODULE_PARM_DESC(whiteness, "Initial whiteness");

#ifdef CONFIG_USB_DEBUG
module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug level: 0-9 (default=0)");
#endif

module_init(qcm_init);
module_exit(qcm_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jaya Kumar");
MODULE_DESCRIPTION("QCM USB Camera");
MODULE_SUPPORTED_DEVICE("QCM USB Camera");