IB: Fix information leak in marshalling code

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / media / video / w9966.c

/*
        Winbond w9966cf Webcam parport driver.

        Version 0.33

        Copyright (C) 2001 Jakob Kemi <jakob.kemi@post.utfors.se>

        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 of the License, or
        (at your option) any later version.

        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.

        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
        Supported devices:
        *Lifeview FlyCam Supra (using the Philips saa7111a chip)

        Does any other model using the w9966 interface chip exist ?

        Todo:

        *Add a working EPP mode, since DMA ECP read isn't implemented
        in the parport drivers. (That's why it's so sloow)

        *Add support for other ccd-control chips than the saa7111
        please send me feedback on what kind of chips you have.

        *Add proper probing. I don't know what's wrong with the IEEE1284
        parport drivers but (IEEE1284_MODE_NIBBLE|IEEE1284_DEVICE_ID)
        and nibble read seems to be broken for some peripherals.

        *Add probing for onboard SRAM, port directions etc. (if possible)

        *Add support for the hardware compressed modes (maybe using v4l2)

        *Fix better support for the capture window (no skewed images, v4l
        interface to capt. window)

        *Probably some bugs that I don't know of

        Please support me by sending feedback!

        Changes:

        Alan Cox:       Removed RGB mode for kernel merge, added THIS_MODULE
                        and owner support for newer module locks
*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/version.h>
#include <linux/videodev2.h>
#include <linux/slab.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-device.h>
#include <linux/parport.h>

/*#define DEBUG*/                               /* Undef me for production */

#ifdef DEBUG
#define DPRINTF(x, a...) printk(KERN_DEBUG "W9966: %s(): "x, __func__ , ##a)
#else
#define DPRINTF(x...)
#endif

/*
 *      Defines, simple typedefs etc.
 */

#define W9966_DRIVERNAME        "W9966CF Webcam"
#define W9966_MAXCAMS           4       /* Maximum number of cameras */
#define W9966_RBUFFER           2048    /* Read buffer (must be an even number) */
#define W9966_SRAMSIZE          131072  /* 128kb */
#define W9966_SRAMID            0x02    /* check w9966cf.pdf */

/* Empirically determined window limits */
#define W9966_WND_MIN_X         16
#define W9966_WND_MIN_Y         14
#define W9966_WND_MAX_X         705
#define W9966_WND_MAX_Y         253
#define W9966_WND_MAX_W         (W9966_WND_MAX_X - W9966_WND_MIN_X)
#define W9966_WND_MAX_H         (W9966_WND_MAX_Y - W9966_WND_MIN_Y)

/* Keep track of our current state */
#define W9966_STATE_PDEV        0x01
#define W9966_STATE_CLAIMED     0x02
#define W9966_STATE_VDEV        0x04

#define W9966_I2C_W_ID          0x48
#define W9966_I2C_R_ID          0x49
#define W9966_I2C_R_DATA        0x08
#define W9966_I2C_R_CLOCK       0x04
#define W9966_I2C_W_DATA        0x02
#define W9966_I2C_W_CLOCK       0x01

struct w9966 {
        struct v4l2_device v4l2_dev;
        unsigned char dev_state;
        unsigned char i2c_state;
        unsigned short ppmode;
        struct parport *pport;
        struct pardevice *pdev;
        struct video_device vdev;
        unsigned short width;
        unsigned short height;
        unsigned char brightness;
        signed char contrast;
        signed char color;
        signed char hue;
        struct mutex lock;
};

/*
 *      Module specific properties
 */

MODULE_AUTHOR("Jakob Kemi <jakob.kemi@post.utfors.se>");
MODULE_DESCRIPTION("Winbond w9966cf WebCam driver (0.32)");
MODULE_LICENSE("GPL");


#ifdef MODULE
static const char *pardev[] = {[0 ... W9966_MAXCAMS] = ""};
#else
static const char *pardev[] = {[0 ... W9966_MAXCAMS] = "aggressive"};
#endif
module_param_array(pardev, charp, NULL, 0);
MODULE_PARM_DESC(pardev, "pardev: where to search for\n"
                "\teach camera. 'aggressive' means brute-force search.\n"
                "\tEg: >pardev=parport3,aggressive,parport2,parport1< would assign\n"
                "\tcam 1 to parport3 and search every parport for cam 2 etc...");

static int parmode;
module_param(parmode, int, 0);
MODULE_PARM_DESC(parmode, "parmode: transfer mode (0=auto, 1=ecp, 2=epp");

static int video_nr = -1;
module_param(video_nr, int, 0);

static struct w9966 w9966_cams[W9966_MAXCAMS];

/*
 *      Private function defines
 */


/* Set camera phase flags, so we know what to uninit when terminating */
static inline void w9966_set_state(struct w9966 *cam, int mask, int val)
{
        cam->dev_state = (cam->dev_state & ~mask) ^ val;
}

/* Get camera phase flags */
static inline int w9966_get_state(struct w9966 *cam, int mask, int val)
{
        return ((cam->dev_state & mask) == val);
}

/* Claim parport for ourself */
static void w9966_pdev_claim(struct w9966 *cam)
{
        if (w9966_get_state(cam, W9966_STATE_CLAIMED, W9966_STATE_CLAIMED))
                return;
        parport_claim_or_block(cam->pdev);
        w9966_set_state(cam, W9966_STATE_CLAIMED, W9966_STATE_CLAIMED);
}

/* Release parport for others to use */
static void w9966_pdev_release(struct w9966 *cam)
{
        if (w9966_get_state(cam, W9966_STATE_CLAIMED, 0))
                return;
        parport_release(cam->pdev);
        w9966_set_state(cam, W9966_STATE_CLAIMED, 0);
}

/* Read register from W9966 interface-chip
   Expects a claimed pdev
   -1 on error, else register data (byte) */
static int w9966_read_reg(struct w9966 *cam, int reg)
{
        /* ECP, read, regtransfer, REG, REG, REG, REG, REG */
        const unsigned char addr = 0x80 | (reg & 0x1f);
        unsigned char val;

        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_ADDR) != 0)
                return -1;
        if (parport_write(cam->pport, &addr, 1) != 1)
                return -1;
        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_DATA) != 0)
                return -1;
        if (parport_read(cam->pport, &val, 1) != 1)
                return -1;

        return val;
}

/* Write register to W9966 interface-chip
   Expects a claimed pdev
   -1 on error */
static int w9966_write_reg(struct w9966 *cam, int reg, int data)
{
        /* ECP, write, regtransfer, REG, REG, REG, REG, REG */
        const unsigned char addr = 0xc0 | (reg & 0x1f);
        const unsigned char val = data;

        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_ADDR) != 0)
                return -1;
        if (parport_write(cam->pport, &addr, 1) != 1)
                return -1;
        if (parport_negotiate(cam->pport, cam->ppmode | IEEE1284_DATA) != 0)
                return -1;
        if (parport_write(cam->pport, &val, 1) != 1)
                return -1;

        return 0;
}

/*
 *      Ugly and primitive i2c protocol functions
 */

/* Sets the data line on the i2c bus.
   Expects a claimed pdev. */
static void w9966_i2c_setsda(struct w9966 *cam, int state)
{
        if (state)
                cam->i2c_state |= W9966_I2C_W_DATA;
        else
                cam->i2c_state &= ~W9966_I2C_W_DATA;

        w9966_write_reg(cam, 0x18, cam->i2c_state);
        udelay(5);
}

/* Get peripheral clock line
   Expects a claimed pdev. */
static int w9966_i2c_getscl(struct w9966 *cam)
{
        const unsigned char state = w9966_read_reg(cam, 0x18);
        return ((state & W9966_I2C_R_CLOCK) > 0);
}

/* Sets the clock line on the i2c bus.
   Expects a claimed pdev. -1 on error */
static int w9966_i2c_setscl(struct w9966 *cam, int state)
{
        unsigned long timeout;

        if (state)
                cam->i2c_state |= W9966_I2C_W_CLOCK;
        else
                cam->i2c_state &= ~W9966_I2C_W_CLOCK;

        w9966_write_reg(cam, 0x18, cam->i2c_state);
        udelay(5);

        /* we go to high, we also expect the peripheral to ack. */
        if (state) {
                timeout = jiffies + 100;
                while (!w9966_i2c_getscl(cam)) {
                        if (time_after(jiffies, timeout))
                                return -1;
                }
        }
        return 0;
}

#if 0
/* Get peripheral data line
   Expects a claimed pdev. */
static int w9966_i2c_getsda(struct w9966 *cam)
{
        const unsigned char state = w9966_read_reg(cam, 0x18);
        return ((state & W9966_I2C_R_DATA) > 0);
}
#endif

/* Write a byte with ack to the i2c bus.
   Expects a claimed pdev. -1 on error */
static int w9966_i2c_wbyte(struct w9966 *cam, int data)
{
        int i;

        for (i = 7; i >= 0; i--) {
                w9966_i2c_setsda(cam, (data >> i) & 0x01);

                if (w9966_i2c_setscl(cam, 1) == -1)
                        return -1;
                w9966_i2c_setscl(cam, 0);
        }

        w9966_i2c_setsda(cam, 1);

        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;
        w9966_i2c_setscl(cam, 0);

        return 0;
}

/* Read a data byte with ack from the i2c-bus
   Expects a claimed pdev. -1 on error */
#if 0
static int w9966_i2c_rbyte(struct w9966 *cam)
{
        unsigned char data = 0x00;
        int i;

        w9966_i2c_setsda(cam, 1);

        for (i = 0; i < 8; i++) {
                if (w9966_i2c_setscl(cam, 1) == -1)
                        return -1;
                data = data << 1;
                if (w9966_i2c_getsda(cam))
                        data |= 0x01;

                w9966_i2c_setscl(cam, 0);
        }
        return data;
}
#endif

/* Read a register from the i2c device.
   Expects claimed pdev. -1 on error */
#if 0
static int w9966_read_reg_i2c(struct w9966 *cam, int reg)
{
        int data;

        w9966_i2c_setsda(cam, 0);
        w9966_i2c_setscl(cam, 0);

        if (w9966_i2c_wbyte(cam, W9966_I2C_W_ID) == -1 ||
            w9966_i2c_wbyte(cam, reg) == -1)
                return -1;

        w9966_i2c_setsda(cam, 1);
        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;
        w9966_i2c_setsda(cam, 0);
        w9966_i2c_setscl(cam, 0);

        if (w9966_i2c_wbyte(cam, W9966_I2C_R_ID) == -1)
                return -1;
        data = w9966_i2c_rbyte(cam);
        if (data == -1)
                return -1;

        w9966_i2c_setsda(cam, 0);

        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;
        w9966_i2c_setsda(cam, 1);

        return data;
}
#endif

/* Write a register to the i2c device.
   Expects claimed pdev. -1 on error */
static int w9966_write_reg_i2c(struct w9966 *cam, int reg, int data)
{
        w9966_i2c_setsda(cam, 0);
        w9966_i2c_setscl(cam, 0);

        if (w9966_i2c_wbyte(cam, W9966_I2C_W_ID) == -1 ||
                        w9966_i2c_wbyte(cam, reg) == -1 ||
                        w9966_i2c_wbyte(cam, data) == -1)
                return -1;

        w9966_i2c_setsda(cam, 0);
        if (w9966_i2c_setscl(cam, 1) == -1)
                return -1;

        w9966_i2c_setsda(cam, 1);

        return 0;
}

/* Find a good length for capture window (used both for W and H)
   A bit ugly but pretty functional. The capture length
   have to match the downscale */
static int w9966_findlen(int near, int size, int maxlen)
{
        int bestlen = size;
        int besterr = abs(near - bestlen);
        int len;

        for (len = size + 1; len < maxlen; len++) {
                int err;
                if (((64 * size) % len) != 0)
                        continue;

                err = abs(near - len);

                /* Only continue as long as we keep getting better values */
                if (err > besterr)
                        break;

                besterr = err;
                bestlen = len;
        }

        return bestlen;
}

/* Modify capture window (if necessary)
   and calculate downscaling
   Return -1 on error */
static int w9966_calcscale(int size, int min, int max, int *beg, int *end, unsigned char *factor)
{
        int maxlen = max - min;
        int len = *end - *beg + 1;
        int newlen = w9966_findlen(len, size, maxlen);
        int err = newlen - len;

        /* Check for bad format */
        if (newlen > maxlen || newlen < size)
                return -1;

        /* Set factor (6 bit fixed) */
        *factor = (64 * size) / newlen;
        if (*factor == 64)
                *factor = 0x00; /* downscale is disabled */
        else
                *factor |= 0x80; /* set downscale-enable bit */

        /* Modify old beginning and end */
        *beg -= err / 2;
        *end += err - (err / 2);

        /* Move window if outside borders */
        if (*beg < min) {
                *end += min - *beg;
                *beg += min - *beg;
        }
        if (*end > max) {
                *beg -= *end - max;
                *end -= *end - max;
        }

        return 0;
}

/* Setup the cameras capture window etc.
   Expects a claimed pdev
   return -1 on error */
static int w9966_setup(struct w9966 *cam, int x1, int y1, int x2, int y2, int w, int h)
{
        unsigned int i;
        unsigned int enh_s, enh_e;
        unsigned char scale_x, scale_y;
        unsigned char regs[0x1c];
        unsigned char saa7111_regs[] = {
                0x21, 0x00, 0xd8, 0x23, 0x00, 0x80, 0x80, 0x00,
                0x88, 0x10, 0x80, 0x40, 0x40, 0x00, 0x01, 0x00,
                0x48, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x71, 0xe7, 0x00, 0x00, 0xc0
        };


        if (w * h * 2 > W9966_SRAMSIZE) {
                DPRINTF("capture window exceeds SRAM size!.\n");
                w = 200; h = 160;       /* Pick default values */
        }

        w &= ~0x1;
        if (w < 2)
                w = 2;
        if (h < 1)
                h = 1;
        if (w > W9966_WND_MAX_W)
                w = W9966_WND_MAX_W;
        if (h > W9966_WND_MAX_H)
                h = W9966_WND_MAX_H;

        cam->width = w;
        cam->height = h;

        enh_s = 0;
        enh_e = w * h * 2;

        /* Modify capture window if necessary and calculate downscaling */
        if (w9966_calcscale(w, W9966_WND_MIN_X, W9966_WND_MAX_X, &x1, &x2, &scale_x) != 0 ||
                        w9966_calcscale(h, W9966_WND_MIN_Y, W9966_WND_MAX_Y, &y1, &y2, &scale_y) != 0)
                return -1;

        DPRINTF("%dx%d, x: %d<->%d, y: %d<->%d, sx: %d/64, sy: %d/64.\n",
                        w, h, x1, x2, y1, y2, scale_x & ~0x80, scale_y & ~0x80);

        /* Setup registers */
        regs[0x00] = 0x00;                      /* Set normal operation */
        regs[0x01] = 0x18;                      /* Capture mode */
        regs[0x02] = scale_y;                   /* V-scaling */
        regs[0x03] = scale_x;                   /* H-scaling */

        /* Capture window */
        regs[0x04] = (x1 & 0x0ff);              /* X-start (8 low bits) */
        regs[0x05] = (x1 & 0x300)>>8;           /* X-start (2 high bits) */
        regs[0x06] = (y1 & 0x0ff);              /* Y-start (8 low bits) */
        regs[0x07] = (y1 & 0x300)>>8;           /* Y-start (2 high bits) */
        regs[0x08] = (x2 & 0x0ff);              /* X-end (8 low bits) */
        regs[0x09] = (x2 & 0x300)>>8;           /* X-end (2 high bits) */
        regs[0x0a] = (y2 & 0x0ff);              /* Y-end (8 low bits) */

        regs[0x0c] = W9966_SRAMID;              /* SRAM-banks (1x 128kb) */

        /* Enhancement layer */
        regs[0x0d] = (enh_s & 0x000ff);         /* Enh. start (0-7) */
        regs[0x0e] = (enh_s & 0x0ff00) >> 8;    /* Enh. start (8-15) */
        regs[0x0f] = (enh_s & 0x70000) >> 16;   /* Enh. start (16-17/18??) */
        regs[0x10] = (enh_e & 0x000ff);         /* Enh. end (0-7) */
        regs[0x11] = (enh_e & 0x0ff00) >> 8;    /* Enh. end (8-15) */
        regs[0x12] = (enh_e & 0x70000) >> 16;   /* Enh. end (16-17/18??) */

        /* Misc */
        regs[0x13] = 0x40;                      /* VEE control (raw 4:2:2) */
        regs[0x17] = 0x00;                      /* ??? */
        regs[0x18] = cam->i2c_state = 0x00;     /* Serial bus */
        regs[0x19] = 0xff;                      /* I/O port direction control */
        regs[0x1a] = 0xff;                      /* I/O port data register */
        regs[0x1b] = 0x10;                      /* ??? */

        /* SAA7111 chip settings */
        saa7111_regs[0x0a] = cam->brightness;
        saa7111_regs[0x0b] = cam->contrast;
        saa7111_regs[0x0c] = cam->color;
        saa7111_regs[0x0d] = cam->hue;

        /* Reset (ECP-fifo & serial-bus) */
        if (w9966_write_reg(cam, 0x00, 0x03) == -1)
                return -1;

        /* Write regs to w9966cf chip */
        for (i = 0; i < 0x1c; i++)
                if (w9966_write_reg(cam, i, regs[i]) == -1)
                        return -1;

        /* Write regs to saa7111 chip */
        for (i = 0; i < 0x20; i++)
                if (w9966_write_reg_i2c(cam, i, saa7111_regs[i]) == -1)
                        return -1;

        return 0;
}

/*
 *      Video4linux interfacing
 */

static int cam_querycap(struct file *file, void  *priv,
                                        struct v4l2_capability *vcap)
{
        struct w9966 *cam = video_drvdata(file);

        strlcpy(vcap->driver, cam->v4l2_dev.name, sizeof(vcap->driver));
        strlcpy(vcap->card, W9966_DRIVERNAME, sizeof(vcap->card));
        strlcpy(vcap->bus_info, "parport", sizeof(vcap->bus_info));
        vcap->version = KERNEL_VERSION(0, 33, 0);
        vcap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE;
        return 0;
}

static int cam_enum_input(struct file *file, void *fh, struct v4l2_input *vin)
{
        if (vin->index > 0)
                return -EINVAL;
        strlcpy(vin->name, "Camera", sizeof(vin->name));
        vin->type = V4L2_INPUT_TYPE_CAMERA;
        vin->audioset = 0;
        vin->tuner = 0;
        vin->std = 0;
        vin->status = 0;
        return 0;
}

static int cam_g_input(struct file *file, void *fh, unsigned int *inp)
{
        *inp = 0;
        return 0;
}

static int cam_s_input(struct file *file, void *fh, unsigned int inp)
{
        return (inp > 0) ? -EINVAL : 0;
}

static int cam_queryctrl(struct file *file, void *priv,
                                        struct v4l2_queryctrl *qc)
{
        switch (qc->id) {
        case V4L2_CID_BRIGHTNESS:
                return v4l2_ctrl_query_fill(qc, 0, 255, 1, 128);
        case V4L2_CID_CONTRAST:
                return v4l2_ctrl_query_fill(qc, -64, 64, 1, 64);
        case V4L2_CID_SATURATION:
                return v4l2_ctrl_query_fill(qc, -64, 64, 1, 64);
        case V4L2_CID_HUE:
                return v4l2_ctrl_query_fill(qc, -128, 127, 1, 0);
        }
        return -EINVAL;
}

static int cam_g_ctrl(struct file *file, void *priv,
                                        struct v4l2_control *ctrl)
{
        struct w9966 *cam = video_drvdata(file);
        int ret = 0;

        switch (ctrl->id) {
        case V4L2_CID_BRIGHTNESS:
                ctrl->value = cam->brightness;
                break;
        case V4L2_CID_CONTRAST:
                ctrl->value = cam->contrast;
                break;
        case V4L2_CID_SATURATION:
                ctrl->value = cam->color;
                break;
        case V4L2_CID_HUE:
                ctrl->value = cam->hue;
                break;
        default:
                ret = -EINVAL;
                break;
        }
        return ret;
}

static int cam_s_ctrl(struct file *file, void *priv,
                                        struct v4l2_control *ctrl)
{
        struct w9966 *cam = video_drvdata(file);
        int ret = 0;

        mutex_lock(&cam->lock);
        switch (ctrl->id) {
        case V4L2_CID_BRIGHTNESS:
                cam->brightness = ctrl->value;
                break;
        case V4L2_CID_CONTRAST:
                cam->contrast = ctrl->value;
                break;
        case V4L2_CID_SATURATION:
                cam->color = ctrl->value;
                break;
        case V4L2_CID_HUE:
                cam->hue = ctrl->value;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        if (ret == 0) {
                w9966_pdev_claim(cam);

                if (w9966_write_reg_i2c(cam, 0x0a, cam->brightness) == -1 ||
                    w9966_write_reg_i2c(cam, 0x0b, cam->contrast) == -1 ||
                    w9966_write_reg_i2c(cam, 0x0c, cam->color) == -1 ||
                    w9966_write_reg_i2c(cam, 0x0d, cam->hue) == -1) {
                        ret = -EIO;
                }

                w9966_pdev_release(cam);
        }
        mutex_unlock(&cam->lock);
        return ret;
}

static int cam_g_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *fmt)
{
        struct w9966 *cam = video_drvdata(file);
        struct v4l2_pix_format *pix = &fmt->fmt.pix;

        pix->width = cam->width;
        pix->height = cam->height;
        pix->pixelformat = V4L2_PIX_FMT_YUYV;
        pix->field = V4L2_FIELD_NONE;
        pix->bytesperline = 2 * cam->width;
        pix->sizeimage = 2 * cam->width * cam->height;
        /* Just a guess */
        pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
        return 0;
}

static int cam_try_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *fmt)
{
        struct v4l2_pix_format *pix = &fmt->fmt.pix;

        if (pix->width < 2)
                pix->width = 2;
        if (pix->height < 1)
                pix->height = 1;
        if (pix->width > W9966_WND_MAX_W)
                pix->width = W9966_WND_MAX_W;
        if (pix->height > W9966_WND_MAX_H)
                pix->height = W9966_WND_MAX_H;
        pix->pixelformat = V4L2_PIX_FMT_YUYV;
        pix->field = V4L2_FIELD_NONE;
        pix->bytesperline = 2 * pix->width;
        pix->sizeimage = 2 * pix->width * pix->height;
        /* Just a guess */
        pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
        return 0;
}

static int cam_s_fmt_vid_cap(struct file *file, void *fh, struct v4l2_format *fmt)
{
        struct w9966 *cam = video_drvdata(file);
        struct v4l2_pix_format *pix = &fmt->fmt.pix;
        int ret = cam_try_fmt_vid_cap(file, fh, fmt);

        if (ret)
                return ret;

        mutex_lock(&cam->lock);
        /* Update camera regs */
        w9966_pdev_claim(cam);
        ret = w9966_setup(cam, 0, 0, 1023, 1023, pix->width, pix->height);
        w9966_pdev_release(cam);
        mutex_unlock(&cam->lock);
        return ret;
}

static int cam_enum_fmt_vid_cap(struct file *file, void *fh, struct v4l2_fmtdesc *fmt)
{
        static struct v4l2_fmtdesc formats[] = {
                { 0, 0, 0,
                  "YUV 4:2:2", V4L2_PIX_FMT_YUYV,
                  { 0, 0, 0, 0 }
                },
        };
        enum v4l2_buf_type type = fmt->type;

        if (fmt->index > 0)
                return -EINVAL;

        *fmt = formats[fmt->index];
        fmt->type = type;
        return 0;
}

/* Capture data */
static ssize_t w9966_v4l_read(struct file *file, char  __user *buf,
                size_t count, loff_t *ppos)
{
        struct w9966 *cam = video_drvdata(file);
        unsigned char addr = 0xa0;      /* ECP, read, CCD-transfer, 00000 */
        unsigned char __user *dest = (unsigned char __user *)buf;
        unsigned long dleft = count;
        unsigned char *tbuf;

        /* Why would anyone want more than this?? */
        if (count > cam->width * cam->height * 2)
                return -EINVAL;

        mutex_lock(&cam->lock);
        w9966_pdev_claim(cam);
        w9966_write_reg(cam, 0x00, 0x02);       /* Reset ECP-FIFO buffer */
        w9966_write_reg(cam, 0x00, 0x00);       /* Return to normal operation */
        w9966_write_reg(cam, 0x01, 0x98);       /* Enable capture */

        /* write special capture-addr and negotiate into data transfer */
        if ((parport_negotiate(cam->pport, cam->ppmode|IEEE1284_ADDR) != 0) ||
                        (parport_write(cam->pport, &addr, 1) != 1) ||
                        (parport_negotiate(cam->pport, cam->ppmode|IEEE1284_DATA) != 0)) {
                w9966_pdev_release(cam);
                mutex_unlock(&cam->lock);
                return -EFAULT;
        }

        tbuf = kmalloc(W9966_RBUFFER, GFP_KERNEL);
        if (tbuf == NULL) {
                count = -ENOMEM;
                goto out;
        }

        while (dleft > 0) {
                unsigned long tsize = (dleft > W9966_RBUFFER) ? W9966_RBUFFER : dleft;

                if (parport_read(cam->pport, tbuf, tsize) < tsize) {
                        count = -EFAULT;
                        goto out;
                }
                if (copy_to_user(dest, tbuf, tsize) != 0) {
                        count = -EFAULT;
                        goto out;
                }
                dest += tsize;
                dleft -= tsize;
        }

        w9966_write_reg(cam, 0x01, 0x18);       /* Disable capture */

out:
        kfree(tbuf);
        w9966_pdev_release(cam);
        mutex_unlock(&cam->lock);

        return count;
}

static const struct v4l2_file_operations w9966_fops = {
        .owner          = THIS_MODULE,
        .ioctl          = video_ioctl2,
        .read           = w9966_v4l_read,
};

static const struct v4l2_ioctl_ops w9966_ioctl_ops = {
        .vidioc_querycap                    = cam_querycap,
        .vidioc_g_input                     = cam_g_input,
        .vidioc_s_input                     = cam_s_input,
        .vidioc_enum_input                  = cam_enum_input,
        .vidioc_queryctrl                   = cam_queryctrl,
        .vidioc_g_ctrl                      = cam_g_ctrl,
        .vidioc_s_ctrl                      = cam_s_ctrl,
        .vidioc_enum_fmt_vid_cap            = cam_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap               = cam_g_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap               = cam_s_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap             = cam_try_fmt_vid_cap,
};


/* Initialize camera device. Setup all internal flags, set a
   default video mode, setup ccd-chip, register v4l device etc..
   Also used for 'probing' of hardware.
   -1 on error */
static int w9966_init(struct w9966 *cam, struct parport *port)
{
        struct v4l2_device *v4l2_dev = &cam->v4l2_dev;

        if (cam->dev_state != 0)
                return -1;

        strlcpy(v4l2_dev->name, "w9966", sizeof(v4l2_dev->name));

        if (v4l2_device_register(NULL, v4l2_dev) < 0) {
                v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
                return -1;
        }
        cam->pport = port;
        cam->brightness = 128;
        cam->contrast = 64;
        cam->color = 64;
        cam->hue = 0;

        /* Select requested transfer mode */
        switch (parmode) {
        default:        /* Auto-detect (priority: hw-ecp, hw-epp, sw-ecp) */
        case 0:
                if (port->modes & PARPORT_MODE_ECP)
                        cam->ppmode = IEEE1284_MODE_ECP;
                else if (port->modes & PARPORT_MODE_EPP)
                        cam->ppmode = IEEE1284_MODE_EPP;
                else
                        cam->ppmode = IEEE1284_MODE_ECP;
                break;
        case 1:         /* hw- or sw-ecp */
                cam->ppmode = IEEE1284_MODE_ECP;
                break;
        case 2:         /* hw- or sw-epp */
                cam->ppmode = IEEE1284_MODE_EPP;
                break;
        }

        /* Tell the parport driver that we exists */
        cam->pdev = parport_register_device(port, "w9966", NULL, NULL, NULL, 0, NULL);
        if (cam->pdev == NULL) {
                DPRINTF("parport_register_device() failed\n");
                return -1;
        }
        w9966_set_state(cam, W9966_STATE_PDEV, W9966_STATE_PDEV);

        w9966_pdev_claim(cam);

        /* Setup a default capture mode */
        if (w9966_setup(cam, 0, 0, 1023, 1023, 200, 160) != 0) {
                DPRINTF("w9966_setup() failed.\n");
                return -1;
        }

        w9966_pdev_release(cam);

        /* Fill in the video_device struct and register us to v4l */
        strlcpy(cam->vdev.name, W9966_DRIVERNAME, sizeof(cam->vdev.name));
        cam->vdev.v4l2_dev = v4l2_dev;
        cam->vdev.fops = &w9966_fops;
        cam->vdev.ioctl_ops = &w9966_ioctl_ops;
        cam->vdev.release = video_device_release_empty;
        video_set_drvdata(&cam->vdev, cam);

        mutex_init(&cam->lock);

        if (video_register_device(&cam->vdev, VFL_TYPE_GRABBER, video_nr) < 0)
                return -1;

        w9966_set_state(cam, W9966_STATE_VDEV, W9966_STATE_VDEV);

        /* All ok */
        v4l2_info(v4l2_dev, "Found and initialized a webcam on %s.\n",
                        cam->pport->name);
        return 0;
}


/* Terminate everything gracefully */
static void w9966_term(struct w9966 *cam)
{
        /* Unregister from v4l */
        if (w9966_get_state(cam, W9966_STATE_VDEV, W9966_STATE_VDEV)) {
                video_unregister_device(&cam->vdev);
                w9966_set_state(cam, W9966_STATE_VDEV, 0);
        }

        /* Terminate from IEEE1284 mode and release pdev block */
        if (w9966_get_state(cam, W9966_STATE_PDEV, W9966_STATE_PDEV)) {
                w9966_pdev_claim(cam);
                parport_negotiate(cam->pport, IEEE1284_MODE_COMPAT);
                w9966_pdev_release(cam);
        }

        /* Unregister from parport */
        if (w9966_get_state(cam, W9966_STATE_PDEV, W9966_STATE_PDEV)) {
                parport_unregister_device(cam->pdev);
                w9966_set_state(cam, W9966_STATE_PDEV, 0);
        }
}


/* Called once for every parport on init */
static void w9966_attach(struct parport *port)
{
        int i;

        for (i = 0; i < W9966_MAXCAMS; i++) {
                if (w9966_cams[i].dev_state != 0)       /* Cam is already assigned */
                        continue;
                if (strcmp(pardev[i], "aggressive") == 0 || strcmp(pardev[i], port->name) == 0) {
                        if (w9966_init(&w9966_cams[i], port) != 0)
                                w9966_term(&w9966_cams[i]);
                        break;  /* return */
                }
        }
}

/* Called once for every parport on termination */
static void w9966_detach(struct parport *port)
{
        int i;

        for (i = 0; i < W9966_MAXCAMS; i++)
                if (w9966_cams[i].dev_state != 0 && w9966_cams[i].pport == port)
                        w9966_term(&w9966_cams[i]);
}


static struct parport_driver w9966_ppd = {
        .name = W9966_DRIVERNAME,
        .attach = w9966_attach,
        .detach = w9966_detach,
};

/* Module entry point */
static int __init w9966_mod_init(void)
{
        int i;

        for (i = 0; i < W9966_MAXCAMS; i++)
                w9966_cams[i].dev_state = 0;

        return parport_register_driver(&w9966_ppd);
}

/* Module cleanup */
static void __exit w9966_mod_term(void)
{
        parport_unregister_driver(&w9966_ppd);
}

module_init(w9966_mod_init);
module_exit(w9966_mod_term);