/*
 *      uvc_v4l2.c  --  USB Video Class Gadget driver
 *
 *      Copyright (C) 2009-2010
 *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 *      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.
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>

#include <media/v4l2-dev.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>

#include "uvc.h"
#include "uvc_queue.h"

/* --------------------------------------------------------------------------
 * Requests handling
 */

static int
uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
{
        struct usb_composite_dev *cdev = uvc->func.config->cdev;
        struct usb_request *req = uvc->control_req;

        if (data->length < 0)
                return usb_ep_set_halt(cdev->gadget->ep0);

        req->length = min_t(unsigned int, uvc->event_length, data->length);
        req->zero = data->length < uvc->event_length;

        memcpy(req->buf, data->data, req->length);

        return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
}

/* --------------------------------------------------------------------------
 * V4L2
 */

struct uvc_format
{
        u8 bpp;
        u32 fcc;
};

static struct uvc_format uvc_formats[] = {
        { 16, V4L2_PIX_FMT_YUYV  },
        { 0,  V4L2_PIX_FMT_MJPEG },
};

static int
uvc_v4l2_get_format(struct uvc_video *video, struct v4l2_format *fmt)
{
        fmt->fmt.pix.pixelformat = video->fcc;
        fmt->fmt.pix.width = video->width;
        fmt->fmt.pix.height = video->height;
        fmt->fmt.pix.field = V4L2_FIELD_NONE;
        fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
        fmt->fmt.pix.sizeimage = video->imagesize;
        fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
        fmt->fmt.pix.priv = 0;

        return 0;
}

static int
uvc_v4l2_set_format(struct uvc_video *video, struct v4l2_format *fmt)
{
        struct uvc_format *format;
        unsigned int imagesize;
        unsigned int bpl;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(uvc_formats); ++i) {
                format = &uvc_formats[i];
                if (format->fcc == fmt->fmt.pix.pixelformat)
                        break;
        }

        if (i == ARRAY_SIZE(uvc_formats)) {
                printk(KERN_INFO "Unsupported format 0x%08x.\n",
                        fmt->fmt.pix.pixelformat);
                return -EINVAL;
        }

        bpl = format->bpp * fmt->fmt.pix.width / 8;
        imagesize = bpl ? bpl * fmt->fmt.pix.height : fmt->fmt.pix.sizeimage;

        video->fcc = format->fcc;
        video->bpp = format->bpp;
        video->width = fmt->fmt.pix.width;
        video->height = fmt->fmt.pix.height;
        video->imagesize = imagesize;

        fmt->fmt.pix.field = V4L2_FIELD_NONE;
        fmt->fmt.pix.bytesperline = bpl;
        fmt->fmt.pix.sizeimage = imagesize;
        fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
        fmt->fmt.pix.priv = 0;

        return 0;
}

static int
uvc_v4l2_open(struct file *file)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_device *uvc = video_get_drvdata(vdev);
        struct uvc_file_handle *handle;

        handle = kzalloc(sizeof(*handle), GFP_KERNEL);
        if (handle == NULL)
                return -ENOMEM;

        v4l2_fh_init(&handle->vfh, vdev);
        v4l2_fh_add(&handle->vfh);

        handle->device = &uvc->video;
        file->private_data = &handle->vfh;

        uvc_function_connect(uvc);
        return 0;
}

static int
uvc_v4l2_release(struct file *file)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_device *uvc = video_get_drvdata(vdev);
        struct uvc_file_handle *handle = to_uvc_file_handle(file->private_data);
        struct uvc_video *video = handle->device;

        uvc_function_disconnect(uvc);

        uvc_video_enable(video, 0);
        uvc_free_buffers(&video->queue);

        file->private_data = NULL;
        v4l2_fh_del(&handle->vfh);
        v4l2_fh_exit(&handle->vfh);
        kfree(handle);

        return 0;
}

static long
uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_device *uvc = video_get_drvdata(vdev);
        struct uvc_file_handle *handle = to_uvc_file_handle(file->private_data);
        struct usb_composite_dev *cdev = uvc->func.config->cdev;
        struct uvc_video *video = &uvc->video;
        int ret = 0;

        switch (cmd) {
        /* Query capabilities */
        case VIDIOC_QUERYCAP:
        {
                struct v4l2_capability *cap = arg;

                memset(cap, 0, sizeof *cap);
                strlcpy(cap->driver, "g_uvc", sizeof(cap->driver));
                strlcpy(cap->card, cdev->gadget->name, sizeof(cap->card));
                strlcpy(cap->bus_info, dev_name(&cdev->gadget->dev),
                        sizeof cap->bus_info);
                cap->version = DRIVER_VERSION_NUMBER;
                cap->capabilities = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;
                break;
        }

        /* Get & Set format */
        case VIDIOC_G_FMT:
        {
                struct v4l2_format *fmt = arg;

                if (fmt->type != video->queue.queue.type)
                        return -EINVAL;

                return uvc_v4l2_get_format(video, fmt);
        }

        case VIDIOC_S_FMT:
        {
                struct v4l2_format *fmt = arg;

                if (fmt->type != video->queue.queue.type)
                        return -EINVAL;

                return uvc_v4l2_set_format(video, fmt);
        }

        /* Buffers & streaming */
        case VIDIOC_REQBUFS:
        {
                struct v4l2_requestbuffers *rb = arg;

                if (rb->type != video->queue.queue.type)
                        return -EINVAL;

                ret = uvc_alloc_buffers(&video->queue, rb);
                if (ret < 0)
                        return ret;

                ret = 0;
                break;
        }

        case VIDIOC_QUERYBUF:
        {
                struct v4l2_buffer *buf = arg;

                return uvc_query_buffer(&video->queue, buf);
        }

        case VIDIOC_QBUF:
                if ((ret = uvc_queue_buffer(&video->queue, arg)) < 0)
                        return ret;

                return uvc_video_pump(video);

        case VIDIOC_DQBUF:
                return uvc_dequeue_buffer(&video->queue, arg,
                        file->f_flags & O_NONBLOCK);

        case VIDIOC_STREAMON:
        {
                int *type = arg;

                if (*type != video->queue.queue.type)
                        return -EINVAL;

                /* Enable UVC video. */
                ret = uvc_video_enable(video, 1);
                if (ret < 0)
                        return ret;

                /*
                 * Complete the alternate setting selection setup phase now that
                 * userspace is ready to provide video frames.
                 */
                uvc_function_setup_continue(uvc);
                uvc->state = UVC_STATE_STREAMING;

                return 0;
        }

        case VIDIOC_STREAMOFF:
        {
                int *type = arg;

                if (*type != video->queue.queue.type)
                        return -EINVAL;

                return uvc_video_enable(video, 0);
        }

        /* Events */
        case VIDIOC_DQEVENT:
        {
                struct v4l2_event *event = arg;

                ret = v4l2_event_dequeue(&handle->vfh, event,
                                         file->f_flags & O_NONBLOCK);
                if (ret == 0 && event->type == UVC_EVENT_SETUP) {
                        struct uvc_event *uvc_event = (void *)&event->u.data;

                        /* Tell the complete callback to generate an event for
                         * the next request that will be enqueued by
                         * uvc_event_write.
                         */
                        uvc->event_setup_out =
                                !(uvc_event->req.bRequestType & USB_DIR_IN);
                        uvc->event_length = uvc_event->req.wLength;
                }

                return ret;
        }

        case VIDIOC_SUBSCRIBE_EVENT:
        {
                struct v4l2_event_subscription *sub = arg;

                if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
                        return -EINVAL;

                return v4l2_event_subscribe(&handle->vfh, arg, 2, NULL);
        }

        case VIDIOC_UNSUBSCRIBE_EVENT:
                return v4l2_event_unsubscribe(&handle->vfh, arg);

        case UVCIOC_SEND_RESPONSE:
                ret = uvc_send_response(uvc, arg);
                break;

        default:
                return -ENOIOCTLCMD;
        }

        return ret;
}

static long
uvc_v4l2_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
}

static int
uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_device *uvc = video_get_drvdata(vdev);

        return uvc_queue_mmap(&uvc->video.queue, vma);
}

static unsigned int
uvc_v4l2_poll(struct file *file, poll_table *wait)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_device *uvc = video_get_drvdata(vdev);

        return uvc_queue_poll(&uvc->video.queue, file, wait);
}

#ifndef CONFIG_MMU
static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
                unsigned long addr, unsigned long len, unsigned long pgoff,
                unsigned long flags)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_device *uvc = video_get_drvdata(vdev);

        return uvc_queue_get_unmapped_area(&uvc->video.queue, pgoff);
}
#endif

static struct v4l2_file_operations uvc_v4l2_fops = {
        .owner          = THIS_MODULE,
        .open           = uvc_v4l2_open,
        .release        = uvc_v4l2_release,
        .ioctl          = uvc_v4l2_ioctl,
        .mmap           = uvc_v4l2_mmap,
        .poll           = uvc_v4l2_poll,
#ifndef CONFIG_MMU
        .get_unmapped_area = uvc_v4l2_get_unmapped_area,
#endif
};