// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * USB USBVISION Video device driver 0.9.10
 *
 * Copyright (c) 1999-2005 Joerg Heckenbach <joerg@heckenbach-aw.de>
 *
 * This module is part of usbvision driver project.
 *
 * Let's call the version 0.... until compression decoding is completely
 * implemented.
 *
 * This driver is written by Jose Ignacio Gijon and Joerg Heckenbach.
 * It was based on USB CPiA driver written by Peter Pregler,
 * Scott J. Bertin and Johannes Erdfelt
 * Ideas are taken from bttv driver by Ralph Metzler, Marcus Metzler &
 * Gerd Knorr and zoran 36120/36125 driver by Pauline Middelink
 * Updates to driver completed by Dwaine P. Garden
 *
 * TODO:
 *     - use submit_urb for all setup packets
 *     - Fix memory settings for nt1004. It is 4 times as big as the
 *       nt1003 memory.
 *     - Add audio on endpoint 3 for nt1004 chip.
 *         Seems impossible, needs a codec interface.  Which one?
 *     - Clean up the driver.
 *     - optimization for performance.
 *     - Add Videotext capability (VBI).  Working on it.....
 *     - Check audio for other devices
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/videodev2.h>
#include <linux/i2c.h>

#include <media/i2c/saa7115.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-event.h>
#include <media/tuner.h>

#include <linux/workqueue.h>

#include "usbvision.h"
#include "usbvision-cards.h"

#define DRIVER_AUTHOR                                   \
        "Joerg Heckenbach <joerg@heckenbach-aw.de>, "   \
        "Dwaine Garden <DwaineGarden@rogers.com>"
#define DRIVER_NAME "usbvision"
#define DRIVER_ALIAS "USBVision"
#define DRIVER_DESC "USBVision USB Video Device Driver for Linux"
#define USBVISION_VERSION_STRING "0.9.11"

#define ENABLE_HEXDUMP  0       /* Enable if you need it */


#ifdef USBVISION_DEBUG
        #define PDEBUG(level, fmt, args...) { \
                if (video_debug & (level)) \
                        printk(KERN_INFO KBUILD_MODNAME ":[%s:%d] " fmt, \
                                __func__, __LINE__ , ## args); \
        }
#else
        #define PDEBUG(level, fmt, args...) do {} while (0)
#endif

#define DBG_IO          (1 << 1)
#define DBG_PROBE       (1 << 2)
#define DBG_MMAP        (1 << 3)

/* String operations */
#define rmspace(str)    while (*str == ' ') str++;
#define goto2next(str)  while (*str != ' ') str++; while (*str == ' ') str++;


/* sequential number of usbvision device */
static int usbvision_nr;

static struct usbvision_v4l2_format_st usbvision_v4l2_format[] = {
        { 1, 1,  8, V4L2_PIX_FMT_GREY },
        { 1, 2, 16, V4L2_PIX_FMT_RGB565 },
        { 1, 3, 24, V4L2_PIX_FMT_RGB24 },
        { 1, 4, 32, V4L2_PIX_FMT_RGB32 },
        { 1, 2, 16, V4L2_PIX_FMT_RGB555 },
        { 1, 2, 16, V4L2_PIX_FMT_YUYV },
        { 1, 2, 12, V4L2_PIX_FMT_YVU420 }, /* 1.5 ! */
        { 1, 2, 16, V4L2_PIX_FMT_YUV422P }
};

/* Function prototypes */
static void usbvision_release(struct usb_usbvision *usbvision);

/* Default initialization of device driver parameters */
/* Set the default format for ISOC endpoint */
static int isoc_mode = ISOC_MODE_COMPRESS;
/* Set the default Debug Mode of the device driver */
static int video_debug;
/* Sequential Number of Video Device */
static int video_nr = -1;
/* Sequential Number of Radio Device */
static int radio_nr = -1;

/* Grab parameters for the device driver */

/* Showing parameters under SYSFS */
module_param(isoc_mode, int, 0444);
module_param(video_debug, int, 0444);
module_param(video_nr, int, 0444);
module_param(radio_nr, int, 0444);

MODULE_PARM_DESC(isoc_mode, " Set the default format for ISOC endpoint.  Default: 0x60 (Compression On)");
MODULE_PARM_DESC(video_debug, " Set the default Debug Mode of the device driver.  Default: 0 (Off)");
MODULE_PARM_DESC(video_nr, "Set video device number (/dev/videoX).  Default: -1 (autodetect)");
MODULE_PARM_DESC(radio_nr, "Set radio device number (/dev/radioX).  Default: -1 (autodetect)");


/* Misc stuff */
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_VERSION(USBVISION_VERSION_STRING);
MODULE_ALIAS(DRIVER_ALIAS);


/*****************************************************************************/
/* SYSFS Code - Copied from the stv680.c usb module.                         */
/* Device information is located at /sys/class/video4linux/video0            */
/* Device parameters information is located at /sys/module/usbvision         */
/* Device USB Information is located at                                      */
/*   /sys/bus/usb/drivers/USBVision Video Grabber                            */
/*****************************************************************************/

#define YES_NO(x) ((x) ? "Yes" : "No")

static inline struct usb_usbvision *cd_to_usbvision(struct device *cd)
{
        struct video_device *vdev = to_video_device(cd);
        return video_get_drvdata(vdev);
}

static ssize_t show_version(struct device *cd,
                            struct device_attribute *attr, char *buf)
{
        return sprintf(buf, "%s\n", USBVISION_VERSION_STRING);
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);

static ssize_t show_model(struct device *cd,
                          struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        return sprintf(buf, "%s\n",
                       usbvision_device_data[usbvision->dev_model].model_string);
}
static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);

static ssize_t show_hue(struct device *cd,
                        struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        s32 val = v4l2_ctrl_g_ctrl(v4l2_ctrl_find(&usbvision->hdl,
                                                  V4L2_CID_HUE));

        return sprintf(buf, "%d\n", val);
}
static DEVICE_ATTR(hue, S_IRUGO, show_hue, NULL);

static ssize_t show_contrast(struct device *cd,
                             struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        s32 val = v4l2_ctrl_g_ctrl(v4l2_ctrl_find(&usbvision->hdl,
                                                  V4L2_CID_CONTRAST));

        return sprintf(buf, "%d\n", val);
}
static DEVICE_ATTR(contrast, S_IRUGO, show_contrast, NULL);

static ssize_t show_brightness(struct device *cd,
                               struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        s32 val = v4l2_ctrl_g_ctrl(v4l2_ctrl_find(&usbvision->hdl,
                                                  V4L2_CID_BRIGHTNESS));

        return sprintf(buf, "%d\n", val);
}
static DEVICE_ATTR(brightness, S_IRUGO, show_brightness, NULL);

static ssize_t show_saturation(struct device *cd,
                               struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        s32 val = v4l2_ctrl_g_ctrl(v4l2_ctrl_find(&usbvision->hdl,
                                                  V4L2_CID_SATURATION));

        return sprintf(buf, "%d\n", val);
}
static DEVICE_ATTR(saturation, S_IRUGO, show_saturation, NULL);

static ssize_t show_streaming(struct device *cd,
                              struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        return sprintf(buf, "%s\n",
                       YES_NO(usbvision->streaming == stream_on ? 1 : 0));
}
static DEVICE_ATTR(streaming, S_IRUGO, show_streaming, NULL);

static ssize_t show_compression(struct device *cd,
                                struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        return sprintf(buf, "%s\n",
                       YES_NO(usbvision->isoc_mode == ISOC_MODE_COMPRESS));
}
static DEVICE_ATTR(compression, S_IRUGO, show_compression, NULL);

static ssize_t show_device_bridge(struct device *cd,
                                  struct device_attribute *attr, char *buf)
{
        struct video_device *vdev = to_video_device(cd);
        struct usb_usbvision *usbvision = video_get_drvdata(vdev);
        return sprintf(buf, "%d\n", usbvision->bridge_type);
}
static DEVICE_ATTR(bridge, S_IRUGO, show_device_bridge, NULL);

static void usbvision_create_sysfs(struct video_device *vdev)
{
        int res;

        if (!vdev)
                return;
        do {
                res = device_create_file(&vdev->dev, &dev_attr_version);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_model);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_hue);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_contrast);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_brightness);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_saturation);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_streaming);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_compression);
                if (res < 0)
                        break;
                res = device_create_file(&vdev->dev, &dev_attr_bridge);
                if (res >= 0)
                        return;
        } while (0);

        dev_err(&vdev->dev, "%s error: %d\n", __func__, res);
}

static void usbvision_remove_sysfs(struct video_device *vdev)
{
        if (vdev) {
                device_remove_file(&vdev->dev, &dev_attr_version);
                device_remove_file(&vdev->dev, &dev_attr_model);
                device_remove_file(&vdev->dev, &dev_attr_hue);
                device_remove_file(&vdev->dev, &dev_attr_contrast);
                device_remove_file(&vdev->dev, &dev_attr_brightness);
                device_remove_file(&vdev->dev, &dev_attr_saturation);
                device_remove_file(&vdev->dev, &dev_attr_streaming);
                device_remove_file(&vdev->dev, &dev_attr_compression);
                device_remove_file(&vdev->dev, &dev_attr_bridge);
        }
}

/*
 * usbvision_open()
 *
 * This is part of Video 4 Linux API. The driver can be opened by one
 * client only (checks internal counter 'usbvision->user'). The procedure
 * then allocates buffers needed for video processing.
 *
 */
static int usbvision_v4l2_open(struct file *file)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int err_code = 0;

        PDEBUG(DBG_IO, "open");

        if (mutex_lock_interruptible(&usbvision->v4l2_lock))
                return -ERESTARTSYS;

        if (usbvision->remove_pending) {
                err_code = -ENODEV;
                goto unlock;
        }
        if (usbvision->user) {
                err_code = -EBUSY;
        } else {
                err_code = v4l2_fh_open(file);
                if (err_code)
                        goto unlock;

                /* Allocate memory for the scratch ring buffer */
                err_code = usbvision_scratch_alloc(usbvision);
                if (isoc_mode == ISOC_MODE_COMPRESS) {
                        /* Allocate intermediate decompression buffers
                           only if needed */
                        err_code = usbvision_decompress_alloc(usbvision);
                }
                if (err_code) {
                        /* Deallocate all buffers if trouble */
                        usbvision_scratch_free(usbvision);
                        usbvision_decompress_free(usbvision);
                }
        }

        /* If so far no errors then we shall start the camera */
        if (!err_code) {
                /* Send init sequence only once, it's large! */
                if (!usbvision->initialized) {
                        int setup_ok = 0;
                        setup_ok = usbvision_setup(usbvision, isoc_mode);
                        if (setup_ok)
                                usbvision->initialized = 1;
                        else
                                err_code = -EBUSY;
                }

                if (!err_code) {
                        usbvision_begin_streaming(usbvision);
                        err_code = usbvision_init_isoc(usbvision);
                        /* device must be initialized before isoc transfer */
                        usbvision_muxsel(usbvision, 0);

                        /* prepare queues */
                        usbvision_empty_framequeues(usbvision);
                        usbvision->user++;
                }
        }

unlock:
        mutex_unlock(&usbvision->v4l2_lock);

        PDEBUG(DBG_IO, "success");
        return err_code;
}

/*
 * usbvision_v4l2_close()
 *
 * This is part of Video 4 Linux API. The procedure
 * stops streaming and deallocates all buffers that were earlier
 * allocated in usbvision_v4l2_open().
 *
 */
static int usbvision_v4l2_close(struct file *file)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int r;

        PDEBUG(DBG_IO, "close");

        mutex_lock(&usbvision->v4l2_lock);
        usbvision_audio_off(usbvision);
        usbvision_restart_isoc(usbvision);
        usbvision_stop_isoc(usbvision);

        usbvision_decompress_free(usbvision);
        usbvision_frames_free(usbvision);
        usbvision_empty_framequeues(usbvision);
        usbvision_scratch_free(usbvision);

        usbvision->user--;
        r = usbvision->remove_pending;
        mutex_unlock(&usbvision->v4l2_lock);

        if (r) {
                printk(KERN_INFO "%s: Final disconnect\n", __func__);
                usbvision_release(usbvision);
                return 0;
        }

        PDEBUG(DBG_IO, "success");
        return v4l2_fh_release(file);
}


/*
 * usbvision_ioctl()
 *
 * This is part of Video 4 Linux API. The procedure handles ioctl() calls.
 *
 */
#ifdef CONFIG_VIDEO_ADV_DEBUG
static int vidioc_g_register(struct file *file, void *priv,
                                struct v4l2_dbg_register *reg)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int err_code;

        /* NT100x has a 8-bit register space */
        err_code = usbvision_read_reg(usbvision, reg->reg&0xff);
        if (err_code < 0) {
                dev_err(&usbvision->vdev.dev,
                        "%s: VIDIOC_DBG_G_REGISTER failed: error %d\n",
                                __func__, err_code);
                return err_code;
        }
        reg->val = err_code;
        reg->size = 1;
        return 0;
}

static int vidioc_s_register(struct file *file, void *priv,
                                const struct v4l2_dbg_register *reg)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int err_code;

        /* NT100x has a 8-bit register space */
        err_code = usbvision_write_reg(usbvision, reg->reg & 0xff, reg->val);
        if (err_code < 0) {
                dev_err(&usbvision->vdev.dev,
                        "%s: VIDIOC_DBG_S_REGISTER failed: error %d\n",
                                __func__, err_code);
                return err_code;
        }
        return 0;
}
#endif

static int vidioc_querycap(struct file *file, void  *priv,
                                        struct v4l2_capability *vc)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        if (!usbvision->dev)
                return -ENODEV;

        strscpy(vc->driver, "USBVision", sizeof(vc->driver));
        strscpy(vc->card,
                usbvision_device_data[usbvision->dev_model].model_string,
                sizeof(vc->card));
        usb_make_path(usbvision->dev, vc->bus_info, sizeof(vc->bus_info));
        vc->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE |
                           V4L2_CAP_STREAMING | V4L2_CAP_DEVICE_CAPS;
        if (usbvision_device_data[usbvision->dev_model].radio)
                vc->capabilities |= V4L2_CAP_RADIO;
        if (usbvision->have_tuner)
                vc->capabilities |= V4L2_CAP_TUNER;
        return 0;
}

static int vidioc_enum_input(struct file *file, void *priv,
                                struct v4l2_input *vi)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int chan;

        if (vi->index >= usbvision->video_inputs)
                return -EINVAL;
        if (usbvision->have_tuner)
                chan = vi->index;
        else
                chan = vi->index + 1; /* skip Television string*/

        /* Determine the requested input characteristics
           specific for each usbvision card model */
        switch (chan) {
        case 0:
                if (usbvision_device_data[usbvision->dev_model].video_channels == 4) {
                        strscpy(vi->name, "White Video Input", sizeof(vi->name));
                } else {
                        strscpy(vi->name, "Television", sizeof(vi->name));
                        vi->type = V4L2_INPUT_TYPE_TUNER;
                        vi->tuner = chan;
                        vi->std = USBVISION_NORMS;
                }
                break;
        case 1:
                vi->type = V4L2_INPUT_TYPE_CAMERA;
                if (usbvision_device_data[usbvision->dev_model].video_channels == 4)
                        strscpy(vi->name, "Green Video Input", sizeof(vi->name));
                else
                        strscpy(vi->name, "Composite Video Input",
                                sizeof(vi->name));
                vi->std = USBVISION_NORMS;
                break;
        case 2:
                vi->type = V4L2_INPUT_TYPE_CAMERA;
                if (usbvision_device_data[usbvision->dev_model].video_channels == 4)
                        strscpy(vi->name, "Yellow Video Input", sizeof(vi->name));
                else
                        strscpy(vi->name, "S-Video Input", sizeof(vi->name));
                vi->std = USBVISION_NORMS;
                break;
        case 3:
                vi->type = V4L2_INPUT_TYPE_CAMERA;
                strscpy(vi->name, "Red Video Input", sizeof(vi->name));
                vi->std = USBVISION_NORMS;
                break;
        }
        return 0;
}

static int vidioc_g_input(struct file *file, void *priv, unsigned int *input)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        *input = usbvision->ctl_input;
        return 0;
}

static int vidioc_s_input(struct file *file, void *priv, unsigned int input)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        if (input >= usbvision->video_inputs)
                return -EINVAL;

        usbvision_muxsel(usbvision, input);
        usbvision_set_input(usbvision);
        usbvision_set_output(usbvision,
                             usbvision->curwidth,
                             usbvision->curheight);
        return 0;
}

static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id id)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        usbvision->tvnorm_id = id;

        call_all(usbvision, video, s_std, usbvision->tvnorm_id);
        /* propagate the change to the decoder */
        usbvision_muxsel(usbvision, usbvision->ctl_input);

        return 0;
}

static int vidioc_g_std(struct file *file, void *priv, v4l2_std_id *id)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        *id = usbvision->tvnorm_id;
        return 0;
}

static int vidioc_g_tuner(struct file *file, void *priv,
                                struct v4l2_tuner *vt)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        if (vt->index)  /* Only tuner 0 */
                return -EINVAL;
        if (vt->type == V4L2_TUNER_RADIO)
                strscpy(vt->name, "Radio", sizeof(vt->name));
        else
                strscpy(vt->name, "Television", sizeof(vt->name));

        /* Let clients fill in the remainder of this struct */
        call_all(usbvision, tuner, g_tuner, vt);

        return 0;
}

static int vidioc_s_tuner(struct file *file, void *priv,
                                const struct v4l2_tuner *vt)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        /* Only one tuner for now */
        if (vt->index)
                return -EINVAL;
        /* let clients handle this */
        call_all(usbvision, tuner, s_tuner, vt);

        return 0;
}

static int vidioc_g_frequency(struct file *file, void *priv,
                                struct v4l2_frequency *freq)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        /* Only one tuner */
        if (freq->tuner)
                return -EINVAL;
        if (freq->type == V4L2_TUNER_RADIO)
                freq->frequency = usbvision->radio_freq;
        else
                freq->frequency = usbvision->tv_freq;

        return 0;
}

static int vidioc_s_frequency(struct file *file, void *priv,
                                const struct v4l2_frequency *freq)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        struct v4l2_frequency new_freq = *freq;

        /* Only one tuner for now */
        if (freq->tuner)
                return -EINVAL;

        call_all(usbvision, tuner, s_frequency, freq);
        call_all(usbvision, tuner, g_frequency, &new_freq);
        if (freq->type == V4L2_TUNER_RADIO)
                usbvision->radio_freq = new_freq.frequency;
        else
                usbvision->tv_freq = new_freq.frequency;

        return 0;
}

static int vidioc_reqbufs(struct file *file,
                           void *priv, struct v4l2_requestbuffers *vr)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int ret;

        RESTRICT_TO_RANGE(vr->count, 1, USBVISION_NUMFRAMES);

        /* Check input validity:
           the user must do a VIDEO CAPTURE and MMAP method. */
        if (vr->memory != V4L2_MEMORY_MMAP)
                return -EINVAL;

        if (usbvision->streaming == stream_on) {
                ret = usbvision_stream_interrupt(usbvision);
                if (ret)
                        return ret;
        }

        usbvision_frames_free(usbvision);
        usbvision_empty_framequeues(usbvision);
        vr->count = usbvision_frames_alloc(usbvision, vr->count);

        usbvision->cur_frame = NULL;

        return 0;
}

static int vidioc_querybuf(struct file *file,
                            void *priv, struct v4l2_buffer *vb)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        struct usbvision_frame *frame;

        /* FIXME : must control
           that buffers are mapped (VIDIOC_REQBUFS has been called) */
        if (vb->index >= usbvision->num_frames)
                return -EINVAL;
        /* Updating the corresponding frame state */
        vb->flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        frame = &usbvision->frame[vb->index];
        if (frame->grabstate >= frame_state_ready)
                vb->flags |= V4L2_BUF_FLAG_QUEUED;
        if (frame->grabstate >= frame_state_done)
                vb->flags |= V4L2_BUF_FLAG_DONE;
        if (frame->grabstate == frame_state_unused)
                vb->flags |= V4L2_BUF_FLAG_MAPPED;
        vb->memory = V4L2_MEMORY_MMAP;

        vb->m.offset = vb->index * PAGE_ALIGN(usbvision->max_frame_size);

        vb->memory = V4L2_MEMORY_MMAP;
        vb->field = V4L2_FIELD_NONE;
        vb->length = usbvision->curwidth *
                usbvision->curheight *
                usbvision->palette.bytes_per_pixel;
        v4l2_buffer_set_timestamp(vb, usbvision->frame[vb->index].ts);
        vb->sequence = usbvision->frame[vb->index].sequence;
        return 0;
}

static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *vb)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        struct usbvision_frame *frame;
        unsigned long lock_flags;

        /* FIXME : works only on VIDEO_CAPTURE MODE, MMAP. */
        if (vb->index >= usbvision->num_frames)
                return -EINVAL;

        frame = &usbvision->frame[vb->index];

        if (frame->grabstate != frame_state_unused)
                return -EAGAIN;

        /* Mark it as ready and enqueue frame */
        frame->grabstate = frame_state_ready;
        frame->scanstate = scan_state_scanning;
        frame->scanlength = 0;  /* Accumulated in usbvision_parse_data() */

        vb->flags &= ~V4L2_BUF_FLAG_DONE;

        /* set v4l2_format index */
        frame->v4l2_format = usbvision->palette;

        spin_lock_irqsave(&usbvision->queue_lock, lock_flags);
        list_add_tail(&usbvision->frame[vb->index].frame, &usbvision->inqueue);
        spin_unlock_irqrestore(&usbvision->queue_lock, lock_flags);

        return 0;
}

static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *vb)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int ret;
        struct usbvision_frame *f;
        unsigned long lock_flags;

        if (list_empty(&(usbvision->outqueue))) {
                if (usbvision->streaming == stream_idle)
                        return -EINVAL;
                ret = wait_event_interruptible
                        (usbvision->wait_frame,
                         !list_empty(&(usbvision->outqueue)));
                if (ret)
                        return ret;
        }

        spin_lock_irqsave(&usbvision->queue_lock, lock_flags);
        f = list_entry(usbvision->outqueue.next,
                       struct usbvision_frame, frame);
        list_del(usbvision->outqueue.next);
        spin_unlock_irqrestore(&usbvision->queue_lock, lock_flags);

        f->grabstate = frame_state_unused;

        vb->memory = V4L2_MEMORY_MMAP;
        vb->flags = V4L2_BUF_FLAG_MAPPED |
                V4L2_BUF_FLAG_QUEUED |
                V4L2_BUF_FLAG_DONE |
                V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        vb->index = f->index;
        vb->sequence = f->sequence;
        v4l2_buffer_set_timestamp(vb, f->ts);
        vb->field = V4L2_FIELD_NONE;
        vb->bytesused = f->scanlength;

        return 0;
}

static int vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        usbvision->streaming = stream_on;
        call_all(usbvision, video, s_stream, 1);

        return 0;
}

static int vidioc_streamoff(struct file *file,
                            void *priv, enum v4l2_buf_type type)
{
        struct usb_usbvision *usbvision = video_drvdata(file);

        if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        if (usbvision->streaming == stream_on) {
                usbvision_stream_interrupt(usbvision);
                /* Stop all video streamings */
                call_all(usbvision, video, s_stream, 0);
        }
        usbvision_empty_framequeues(usbvision);

        return 0;
}

static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
                                        struct v4l2_fmtdesc *vfd)
{
        if (vfd->index >= USBVISION_SUPPORTED_PALETTES - 1)
                return -EINVAL;
        vfd->pixelformat = usbvision_v4l2_format[vfd->index].format;
        return 0;
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                                        struct v4l2_format *vf)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        vf->fmt.pix.width = usbvision->curwidth;
        vf->fmt.pix.height = usbvision->curheight;
        vf->fmt.pix.pixelformat = usbvision->palette.format;
        vf->fmt.pix.bytesperline =
                usbvision->curwidth * usbvision->palette.bytes_per_pixel;
        vf->fmt.pix.sizeimage = vf->fmt.pix.bytesperline * usbvision->curheight;
        vf->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
        vf->fmt.pix.field = V4L2_FIELD_NONE; /* Always progressive image */

        return 0;
}

static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
                               struct v4l2_format *vf)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int format_idx;

        /* Find requested format in available ones */
        for (format_idx = 0; format_idx < USBVISION_SUPPORTED_PALETTES; format_idx++) {
                if (vf->fmt.pix.pixelformat ==
                   usbvision_v4l2_format[format_idx].format) {
                        usbvision->palette = usbvision_v4l2_format[format_idx];
                        break;
                }
        }
        /* robustness */
        if (format_idx == USBVISION_SUPPORTED_PALETTES)
                return -EINVAL;
        RESTRICT_TO_RANGE(vf->fmt.pix.width, MIN_FRAME_WIDTH, MAX_FRAME_WIDTH);
        RESTRICT_TO_RANGE(vf->fmt.pix.height, MIN_FRAME_HEIGHT, MAX_FRAME_HEIGHT);

        vf->fmt.pix.bytesperline = vf->fmt.pix.width*
                usbvision->palette.bytes_per_pixel;
        vf->fmt.pix.sizeimage = vf->fmt.pix.bytesperline*vf->fmt.pix.height;
        vf->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
        vf->fmt.pix.field = V4L2_FIELD_NONE; /* Always progressive image */

        return 0;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                               struct v4l2_format *vf)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int ret;

        ret = vidioc_try_fmt_vid_cap(file, priv, vf);
        if (ret)
                return ret;

        /* stop io in case it is already in progress */
        if (usbvision->streaming == stream_on) {
                ret = usbvision_stream_interrupt(usbvision);
                if (ret)
                        return ret;
        }
        usbvision_frames_free(usbvision);
        usbvision_empty_framequeues(usbvision);

        usbvision->cur_frame = NULL;

        /* by now we are committed to the new data... */
        usbvision_set_output(usbvision, vf->fmt.pix.width, vf->fmt.pix.height);

        return 0;
}

static ssize_t usbvision_read(struct file *file, char __user *buf,
                      size_t count, loff_t *ppos)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int noblock = file->f_flags & O_NONBLOCK;
        unsigned long lock_flags;
        int ret, i;
        struct usbvision_frame *frame;

        PDEBUG(DBG_IO, "%s: %ld bytes, noblock=%d", __func__,
               (unsigned long)count, noblock);

        if (!USBVISION_IS_OPERATIONAL(usbvision) || !buf)
                return -EFAULT;

        /* This entry point is compatible with the mmap routines
           so that a user can do either VIDIOC_QBUF/VIDIOC_DQBUF
           to get frames or call read on the device. */
        if (!usbvision->num_frames) {
                /* First, allocate some frames to work with
                   if this has not been done with VIDIOC_REQBUF */
                usbvision_frames_free(usbvision);
                usbvision_empty_framequeues(usbvision);
                usbvision_frames_alloc(usbvision, USBVISION_NUMFRAMES);
        }

        if (usbvision->streaming != stream_on) {
                /* no stream is running, make it running ! */
                usbvision->streaming = stream_on;
                call_all(usbvision, video, s_stream, 1);
        }

        /* Then, enqueue as many frames as possible
           (like a user of VIDIOC_QBUF would do) */
        for (i = 0; i < usbvision->num_frames; i++) {
                frame = &usbvision->frame[i];
                if (frame->grabstate == frame_state_unused) {
                        /* Mark it as ready and enqueue frame */
                        frame->grabstate = frame_state_ready;
                        frame->scanstate = scan_state_scanning;
                        /* Accumulated in usbvision_parse_data() */
                        frame->scanlength = 0;

                        /* set v4l2_format index */
                        frame->v4l2_format = usbvision->palette;

                        spin_lock_irqsave(&usbvision->queue_lock, lock_flags);
                        list_add_tail(&frame->frame, &usbvision->inqueue);
                        spin_unlock_irqrestore(&usbvision->queue_lock,
                                               lock_flags);
                }
        }

        /* Then try to steal a frame (like a VIDIOC_DQBUF would do) */
        if (list_empty(&(usbvision->outqueue))) {
                if (noblock)
                        return -EAGAIN;

                ret = wait_event_interruptible
                        (usbvision->wait_frame,
                         !list_empty(&(usbvision->outqueue)));
                if (ret)
                        return ret;
        }

        spin_lock_irqsave(&usbvision->queue_lock, lock_flags);
        frame = list_entry(usbvision->outqueue.next,
                           struct usbvision_frame, frame);
        list_del(usbvision->outqueue.next);
        spin_unlock_irqrestore(&usbvision->queue_lock, lock_flags);

        /* An error returns an empty frame */
        if (frame->grabstate == frame_state_error) {
                frame->bytes_read = 0;
                return 0;
        }

        PDEBUG(DBG_IO, "%s: frmx=%d, bytes_read=%ld, scanlength=%ld",
               __func__,
               frame->index, frame->bytes_read, frame->scanlength);

        /* copy bytes to user space; we allow for partials reads */
        if ((count + frame->bytes_read) > (unsigned long)frame->scanlength)
                count = frame->scanlength - frame->bytes_read;

        if (copy_to_user(buf, frame->data + frame->bytes_read, count))
                return -EFAULT;

        frame->bytes_read += count;
        PDEBUG(DBG_IO, "%s: {copy} count used=%ld, new bytes_read=%ld",
               __func__,
               (unsigned long)count, frame->bytes_read);

        /*
         * FIXME:
         * For now, forget the frame if it has not been read in one shot.
         */
        frame->bytes_read = 0;

        /* Mark it as available to be used again. */
        frame->grabstate = frame_state_unused;

        return count;
}

static ssize_t usbvision_v4l2_read(struct file *file, char __user *buf,
                      size_t count, loff_t *ppos)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int res;

        if (mutex_lock_interruptible(&usbvision->v4l2_lock))
                return -ERESTARTSYS;
        res = usbvision_read(file, buf, count, ppos);
        mutex_unlock(&usbvision->v4l2_lock);
        return res;
}

static int usbvision_mmap(struct file *file, struct vm_area_struct *vma)
{
        unsigned long size = vma->vm_end - vma->vm_start,
                start = vma->vm_start;
        void *pos;
        u32 i;
        struct usb_usbvision *usbvision = video_drvdata(file);

        PDEBUG(DBG_MMAP, "mmap");

        if (!USBVISION_IS_OPERATIONAL(usbvision))
                return -EFAULT;

        if (!(vma->vm_flags & VM_WRITE) ||
            size != PAGE_ALIGN(usbvision->max_frame_size)) {
                return -EINVAL;
        }

        for (i = 0; i < usbvision->num_frames; i++) {
                if (((PAGE_ALIGN(usbvision->max_frame_size)*i) >> PAGE_SHIFT) ==
                    vma->vm_pgoff)
                        break;
        }
        if (i == usbvision->num_frames) {
                PDEBUG(DBG_MMAP,
                       "mmap: user supplied mapping address is out of range");
                return -EINVAL;
        }

        /* VM_IO is eventually going to replace PageReserved altogether */
        vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;

        pos = usbvision->frame[i].data;
        while (size > 0) {
                if (vm_insert_page(vma, start, vmalloc_to_page(pos))) {
                        PDEBUG(DBG_MMAP, "mmap: vm_insert_page failed");
                        return -EAGAIN;
                }
                start += PAGE_SIZE;
                pos += PAGE_SIZE;
                size -= PAGE_SIZE;
        }

        return 0;
}

static int usbvision_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int res;

        if (mutex_lock_interruptible(&usbvision->v4l2_lock))
                return -ERESTARTSYS;
        res = usbvision_mmap(file, vma);
        mutex_unlock(&usbvision->v4l2_lock);
        return res;
}

/*
 * Here comes the stuff for radio on usbvision based devices
 *
 */
static int usbvision_radio_open(struct file *file)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int err_code = 0;

        PDEBUG(DBG_IO, "%s:", __func__);

        if (mutex_lock_interruptible(&usbvision->v4l2_lock))
                return -ERESTARTSYS;

        if (usbvision->remove_pending) {
                err_code = -ENODEV;
                goto out;
        }
        err_code = v4l2_fh_open(file);
        if (err_code)
                goto out;
        if (usbvision->user) {
                dev_err(&usbvision->rdev.dev,
                        "%s: Someone tried to open an already opened USBVision Radio!\n",
                                __func__);
                err_code = -EBUSY;
        } else {
                /* Alternate interface 1 is is the biggest frame size */
                err_code = usbvision_set_alternate(usbvision);
                if (err_code < 0) {
                        usbvision->last_error = err_code;
                        err_code = -EBUSY;
                        goto out;
                }

                /* If so far no errors then we shall start the radio */
                usbvision->radio = 1;
                call_all(usbvision, tuner, s_radio);
                usbvision_set_audio(usbvision, USBVISION_AUDIO_RADIO);
                usbvision->user++;
        }
out:
        mutex_unlock(&usbvision->v4l2_lock);
        return err_code;
}


static int usbvision_radio_close(struct file *file)
{
        struct usb_usbvision *usbvision = video_drvdata(file);
        int r;

        PDEBUG(DBG_IO, "");

        mutex_lock(&usbvision->v4l2_lock);
        /* Set packet size to 0 */
        usbvision->iface_alt = 0;
        if (usbvision->dev)
                usb_set_interface(usbvision->dev, usbvision->iface,
                                  usbvision->iface_alt);

        usbvision_audio_off(usbvision);
        usbvision->radio = 0;
        usbvision->user--;
        r = usbvision->remove_pending;
        mutex_unlock(&usbvision->v4l2_lock);

        if (r) {
                printk(KERN_INFO "%s: Final disconnect\n", __func__);
                v4l2_fh_release(file);
                usbvision_release(usbvision);
                return 0;
        }

        PDEBUG(DBG_IO, "success");
        return v4l2_fh_release(file);
}

/* Video registration stuff */

/* Video template */
static const struct v4l2_file_operations usbvision_fops = {
        .owner             = THIS_MODULE,
        .open           = usbvision_v4l2_open,
        .release        = usbvision_v4l2_close,
        .read           = usbvision_v4l2_read,
        .mmap           = usbvision_v4l2_mmap,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops usbvision_ioctl_ops = {
        .vidioc_querycap      = vidioc_querycap,
        .vidioc_enum_fmt_vid_cap  = vidioc_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap     = vidioc_g_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap   = vidioc_try_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap     = vidioc_s_fmt_vid_cap,
        .vidioc_reqbufs       = vidioc_reqbufs,
        .vidioc_querybuf      = vidioc_querybuf,
        .vidioc_qbuf          = vidioc_qbuf,
        .vidioc_dqbuf         = vidioc_dqbuf,
        .vidioc_s_std         = vidioc_s_std,
        .vidioc_g_std         = vidioc_g_std,
        .vidioc_enum_input    = vidioc_enum_input,
        .vidioc_g_input       = vidioc_g_input,
        .vidioc_s_input       = vidioc_s_input,
        .vidioc_streamon      = vidioc_streamon,
        .vidioc_streamoff     = vidioc_streamoff,
        .vidioc_g_tuner       = vidioc_g_tuner,
        .vidioc_s_tuner       = vidioc_s_tuner,
        .vidioc_g_frequency   = vidioc_g_frequency,
        .vidioc_s_frequency   = vidioc_s_frequency,
        .vidioc_log_status    = v4l2_ctrl_log_status,
        .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .vidioc_g_register    = vidioc_g_register,
        .vidioc_s_register    = vidioc_s_register,
#endif
};

static struct video_device usbvision_video_template = {
        .fops           = &usbvision_fops,
        .ioctl_ops      = &usbvision_ioctl_ops,
        .name           = "usbvision-video",
        .release        = video_device_release_empty,
        .tvnorms        = USBVISION_NORMS,
};


/* Radio template */
static const struct v4l2_file_operations usbvision_radio_fops = {
        .owner             = THIS_MODULE,
        .open           = usbvision_radio_open,
        .release        = usbvision_radio_close,
        .poll           = v4l2_ctrl_poll,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops usbvision_radio_ioctl_ops = {
        .vidioc_querycap      = vidioc_querycap,
        .vidioc_g_tuner       = vidioc_g_tuner,
        .vidioc_s_tuner       = vidioc_s_tuner,
        .vidioc_g_frequency   = vidioc_g_frequency,
        .vidioc_s_frequency   = vidioc_s_frequency,
        .vidioc_log_status    = v4l2_ctrl_log_status,
        .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static struct video_device usbvision_radio_template = {
        .fops           = &usbvision_radio_fops,
        .name           = "usbvision-radio",
        .release        = video_device_release_empty,
        .ioctl_ops      = &usbvision_radio_ioctl_ops,
};


static void usbvision_vdev_init(struct usb_usbvision *usbvision,
                                struct video_device *vdev,
                                const struct video_device *vdev_template,
                                const char *name)
{
        struct usb_device *usb_dev = usbvision->dev;

        if (!usb_dev) {
                dev_err(&usbvision->dev->dev,
                        "%s: usbvision->dev is not set\n", __func__);
                return;
        }

        *vdev = *vdev_template;
        vdev->lock = &usbvision->v4l2_lock;
        vdev->v4l2_dev = &usbvision->v4l2_dev;
        snprintf(vdev->name, sizeof(vdev->name), "%s", name);
        video_set_drvdata(vdev, usbvision);
}

/* unregister video4linux devices */
static void usbvision_unregister_video(struct usb_usbvision *usbvision)
{
        /* Radio Device: */
        if (video_is_registered(&usbvision->rdev)) {
                PDEBUG(DBG_PROBE, "unregister %s [v4l2]",
                       video_device_node_name(&usbvision->rdev));
                video_unregister_device(&usbvision->rdev);
        }

        /* Video Device: */
        if (video_is_registered(&usbvision->vdev)) {
                PDEBUG(DBG_PROBE, "unregister %s [v4l2]",
                       video_device_node_name(&usbvision->vdev));
                video_unregister_device(&usbvision->vdev);
        }
}

/* register video4linux devices */
static int usbvision_register_video(struct usb_usbvision *usbvision)
{
        int res = -ENOMEM;

        /* Video Device: */
        usbvision_vdev_init(usbvision, &usbvision->vdev,
                              &usbvision_video_template, "USBVision Video");
        if (!usbvision->have_tuner) {
                v4l2_disable_ioctl(&usbvision->vdev, VIDIOC_G_FREQUENCY);
                v4l2_disable_ioctl(&usbvision->vdev, VIDIOC_S_TUNER);
                v4l2_disable_ioctl(&usbvision->vdev, VIDIOC_G_FREQUENCY);
                v4l2_disable_ioctl(&usbvision->vdev, VIDIOC_S_TUNER);
        }
        usbvision->vdev.device_caps = V4L2_CAP_VIDEO_CAPTURE |
                                      V4L2_CAP_READWRITE | V4L2_CAP_STREAMING;
        if (usbvision->have_tuner)
                usbvision->vdev.device_caps |= V4L2_CAP_TUNER;

        if (video_register_device(&usbvision->vdev, VFL_TYPE_VIDEO, video_nr) < 0)
                goto err_exit;
        printk(KERN_INFO "USBVision[%d]: registered USBVision Video device %s [v4l2]\n",
               usbvision->nr, video_device_node_name(&usbvision->vdev));

        /* Radio Device: */
        if (usbvision_device_data[usbvision->dev_model].radio) {
                /* usbvision has radio */
                usbvision_vdev_init(usbvision, &usbvision->rdev,
                              &usbvision_radio_template, "USBVision Radio");
                usbvision->rdev.device_caps = V4L2_CAP_RADIO | V4L2_CAP_TUNER;
                if (video_register_device(&usbvision->rdev, VFL_TYPE_RADIO, radio_nr) < 0)
                        goto err_exit;
                printk(KERN_INFO "USBVision[%d]: registered USBVision Radio device %s [v4l2]\n",
                       usbvision->nr, video_device_node_name(&usbvision->rdev));
        }
        /* all done */
        return 0;

 err_exit:
        dev_err(&usbvision->dev->dev,
                "USBVision[%d]: video_register_device() failed\n",
                        usbvision->nr);
        usbvision_unregister_video(usbvision);
        return res;
}

/*
 * usbvision_alloc()
 *
 * This code allocates the struct usb_usbvision.
 * It is filled with default values.
 *
 * Returns NULL on error, a pointer to usb_usbvision else.
 *
 */
static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
                                             struct usb_interface *intf)
{
        struct usb_usbvision *usbvision;

        usbvision = kzalloc(sizeof(*usbvision), GFP_KERNEL);
        if (!usbvision)
                return NULL;

        usbvision->dev = dev;
        if (v4l2_device_register(&intf->dev, &usbvision->v4l2_dev))
                goto err_free;

        if (v4l2_ctrl_handler_init(&usbvision->hdl, 4))
                goto err_unreg;
        usbvision->v4l2_dev.ctrl_handler = &usbvision->hdl;
        mutex_init(&usbvision->v4l2_lock);

        /* prepare control urb for control messages during interrupts */
        usbvision->ctrl_urb = usb_alloc_urb(USBVISION_URB_FRAMES, GFP_KERNEL);
        if (!usbvision->ctrl_urb)
                goto err_unreg;

        return usbvision;

err_unreg:
        v4l2_ctrl_handler_free(&usbvision->hdl);
        v4l2_device_unregister(&usbvision->v4l2_dev);
err_free:
        kfree(usbvision);
        return NULL;
}

/*
 * usbvision_release()
 *
 * This code does final release of struct usb_usbvision. This happens
 * after the device is disconnected -and- all clients closed their files.
 *
 */
static void usbvision_release(struct usb_usbvision *usbvision)
{
        PDEBUG(DBG_PROBE, "");

        usbvision->initialized = 0;

        usbvision_remove_sysfs(&usbvision->vdev);
        usbvision_unregister_video(usbvision);
        kfree(usbvision->alt_max_pkt_size);

        usb_free_urb(usbvision->ctrl_urb);

        v4l2_ctrl_handler_free(&usbvision->hdl);
        v4l2_device_unregister(&usbvision->v4l2_dev);
        kfree(usbvision);

        PDEBUG(DBG_PROBE, "success");
}


/*********************** usb interface **********************************/

static void usbvision_configure_video(struct usb_usbvision *usbvision)
{
        int model;

        if (!usbvision)
                return;

        model = usbvision->dev_model;
        usbvision->palette = usbvision_v4l2_format[2]; /* V4L2_PIX_FMT_RGB24; */

        if (usbvision_device_data[usbvision->dev_model].vin_reg2_override) {
                usbvision->vin_reg2_preset =
                        usbvision_device_data[usbvision->dev_model].vin_reg2;
        } else {
                usbvision->vin_reg2_preset = 0;
        }

        usbvision->tvnorm_id = usbvision_device_data[model].video_norm;
        usbvision->video_inputs = usbvision_device_data[model].video_channels;
        usbvision->ctl_input = 0;
        usbvision->radio_freq = 87.5 * 16000;
        usbvision->tv_freq = 400 * 16;

        /* This should be here to make i2c clients to be able to register */
        /* first switch off audio */
        if (usbvision_device_data[model].audio_channels > 0)
                usbvision_audio_off(usbvision);
        /* and then power up the tuner */
        usbvision_power_on(usbvision);
        usbvision_i2c_register(usbvision);
}

/*
 * usbvision_probe()
 *
 * This procedure queries device descriptor and accepts the interface
 * if it looks like USBVISION video device
 *
 */
static int usbvision_probe(struct usb_interface *intf,
                           const struct usb_device_id *devid)
{
        struct usb_device *dev = usb_get_dev(interface_to_usbdev(intf));
        struct usb_interface *uif;
        __u8 ifnum = intf->altsetting->desc.bInterfaceNumber;
        const struct usb_host_interface *interface;
        struct usb_usbvision *usbvision = NULL;
        const struct usb_endpoint_descriptor *endpoint;
        int model, i, ret;

        PDEBUG(DBG_PROBE, "VID=%#04x, PID=%#04x, ifnum=%u",
                                le16_to_cpu(dev->descriptor.idVendor),
                                le16_to_cpu(dev->descriptor.idProduct), ifnum);

        model = devid->driver_info;
        if (model < 0 || model >= usbvision_device_data_size) {
                PDEBUG(DBG_PROBE, "model out of bounds %d", model);
                ret = -ENODEV;
                goto err_usb;
        }
        printk(KERN_INFO "%s: %s found\n", __func__,
                                usbvision_device_data[model].model_string);

        if (usbvision_device_data[model].interface >= 0)
                interface = &dev->actconfig->interface[usbvision_device_data[model].interface]->altsetting[0];
        else if (ifnum < dev->actconfig->desc.bNumInterfaces)
                interface = &dev->actconfig->interface[ifnum]->altsetting[0];
        else {
                dev_err(&intf->dev, "interface %d is invalid, max is %d\n",
                    ifnum, dev->actconfig->desc.bNumInterfaces - 1);
                ret = -ENODEV;
                goto err_usb;
        }

        if (interface->desc.bNumEndpoints < 2) {
                dev_err(&intf->dev, "interface %d has %d endpoints, but must have minimum 2\n",
                        ifnum, interface->desc.bNumEndpoints);
                ret = -ENODEV;
                goto err_usb;
        }
        endpoint = &interface->endpoint[1].desc;

        if (!usb_endpoint_xfer_isoc(endpoint)) {
                dev_err(&intf->dev, "%s: interface %d. has non-ISO endpoint!\n",
                    __func__, ifnum);
                dev_err(&intf->dev, "%s: Endpoint attributes %d",
                    __func__, endpoint->bmAttributes);
                ret = -ENODEV;
                goto err_usb;
        }
        if (usb_endpoint_dir_out(endpoint)) {
                dev_err(&intf->dev, "%s: interface %d. has ISO OUT endpoint!\n",
                    __func__, ifnum);
                ret = -ENODEV;
                goto err_usb;
        }

        usbvision = usbvision_alloc(dev, intf);
        if (!usbvision) {
                dev_err(&intf->dev, "%s: couldn't allocate USBVision struct\n", __func__);
                ret = -ENOMEM;
                goto err_usb;
        }

        if (dev->descriptor.bNumConfigurations > 1)
                usbvision->bridge_type = BRIDGE_NT1004;
        else if (model == DAZZLE_DVC_90_REV_1_SECAM)
                usbvision->bridge_type = BRIDGE_NT1005;
        else
                usbvision->bridge_type = BRIDGE_NT1003;
        PDEBUG(DBG_PROBE, "bridge_type %d", usbvision->bridge_type);

        /* compute alternate max packet sizes */
        uif = dev->actconfig->interface[0];

        usbvision->num_alt = uif->num_altsetting;
        PDEBUG(DBG_PROBE, "Alternate settings: %i", usbvision->num_alt);
        usbvision->alt_max_pkt_size = kmalloc_array(32, usbvision->num_alt,
                                                    GFP_KERNEL);
        if (!usbvision->alt_max_pkt_size) {
                ret = -ENOMEM;
                goto err_pkt;
        }

        for (i = 0; i < usbvision->num_alt; i++) {
                u16 tmp;

                if (uif->altsetting[i].desc.bNumEndpoints < 2) {
                        ret = -ENODEV;
                        goto err_pkt;
                }

                tmp = le16_to_cpu(uif->altsetting[i].endpoint[1].desc.
                                      wMaxPacketSize);
                usbvision->alt_max_pkt_size[i] =
                        (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1);
                PDEBUG(DBG_PROBE, "Alternate setting %i, max size= %i", i,
                       usbvision->alt_max_pkt_size[i]);
        }


        usbvision->nr = usbvision_nr++;

        spin_lock_init(&usbvision->queue_lock);
        init_waitqueue_head(&usbvision->wait_frame);
        init_waitqueue_head(&usbvision->wait_stream);

        usbvision->have_tuner = usbvision_device_data[model].tuner;
        if (usbvision->have_tuner)
                usbvision->tuner_type = usbvision_device_data[model].tuner_type;

        usbvision->dev_model = model;
        usbvision->remove_pending = 0;
        usbvision->iface = ifnum;
        usbvision->iface_alt = 0;
        usbvision->video_endp = endpoint->bEndpointAddress;
        usbvision->isoc_packet_size = 0;
        usbvision->usb_bandwidth = 0;
        usbvision->user = 0;
        usbvision->streaming = stream_off;
        usbvision_configure_video(usbvision);
        usbvision_register_video(usbvision);

        usbvision_create_sysfs(&usbvision->vdev);

        PDEBUG(DBG_PROBE, "success");
        return 0;

err_pkt:
        usbvision_release(usbvision);
err_usb:
        usb_put_dev(dev);
        return ret;
}


/*
 * usbvision_disconnect()
 *
 * This procedure stops all driver activity, deallocates interface-private
 * structure (pointed by 'ptr') and after that driver should be removable
 * with no ill consequences.
 *
 */
static void usbvision_disconnect(struct usb_interface *intf)
{
        struct usb_usbvision *usbvision = to_usbvision(usb_get_intfdata(intf));
        int u;

        PDEBUG(DBG_PROBE, "");

        if (!usbvision) {
                pr_err("%s: usb_get_intfdata() failed\n", __func__);
                return;
        }

        mutex_lock(&usbvision->v4l2_lock);

        /* At this time we ask to cancel outstanding URBs */
        usbvision_stop_isoc(usbvision);

        v4l2_device_disconnect(&usbvision->v4l2_dev);
        usbvision_i2c_unregister(usbvision);
        usbvision->remove_pending = 1;  /* Now all ISO data will be ignored */
        u = usbvision->user;

        usb_put_dev(usbvision->dev);
        usbvision->dev = NULL;  /* USB device is no more */

        mutex_unlock(&usbvision->v4l2_lock);

        if (u) {
                printk(KERN_INFO "%s: In use, disconnect pending\n",
                       __func__);
                wake_up_interruptible(&usbvision->wait_frame);
                wake_up_interruptible(&usbvision->wait_stream);
        } else {
                usbvision_release(usbvision);
        }

        PDEBUG(DBG_PROBE, "success");
}

static struct usb_driver usbvision_driver = {
        .name           = "usbvision",
        .id_table       = usbvision_table,
        .probe          = usbvision_probe,
        .disconnect     = usbvision_disconnect,
};

/*
 * usbvision_init()
 *
 * This code is run to initialize the driver.
 *
 */
static int __init usbvision_init(void)
{
        int err_code;

        PDEBUG(DBG_PROBE, "");

        PDEBUG(DBG_IO,  "IO      debugging is enabled [video]");
        PDEBUG(DBG_PROBE, "PROBE   debugging is enabled [video]");
        PDEBUG(DBG_MMAP, "MMAP    debugging is enabled [video]");

        /* disable planar mode support unless compression enabled */
        if (isoc_mode != ISOC_MODE_COMPRESS) {
                /* FIXME : not the right way to set supported flag */
                usbvision_v4l2_format[6].supported = 0; /* V4L2_PIX_FMT_YVU420 */
                usbvision_v4l2_format[7].supported = 0; /* V4L2_PIX_FMT_YUV422P */
        }

        err_code = usb_register(&usbvision_driver);

        if (err_code == 0) {
                printk(KERN_INFO DRIVER_DESC " : " USBVISION_VERSION_STRING "\n");
                PDEBUG(DBG_PROBE, "success");
        }
        return err_code;
}

static void __exit usbvision_exit(void)
{
        PDEBUG(DBG_PROBE, "");

        usb_deregister(&usbvision_driver);
        PDEBUG(DBG_PROBE, "success");
}

module_init(usbvision_init);
module_exit(usbvision_exit);