/*
 * Copyright (c) 2013 Lubomir Rintel
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * Fushicai USBTV007 Audio-Video Grabber Driver
 *
 * No physical hardware was harmed running Windows during the
 * reverse-engineering activity
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>

#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-vmalloc.h>

/* Hardware. */
#define USBTV_VIDEO_ENDP        0x81
#define USBTV_AUDIO_ENDP        0x83
#define USBTV_BASE              0xc000
#define USBTV_CONTROL_REG       11
#define USBTV_REQUEST_REG       12

/* Number of concurrent isochronous urbs submitted.
 * Higher numbers was seen to overly saturate the USB bus. */
#define USBTV_ISOC_TRANSFERS    16
#define USBTV_ISOC_PACKETS      8

#define USBTV_CHUNK_SIZE        256
#define USBTV_CHUNK             240

#define USBTV_AUDIO_URBSIZE     20480
#define USBTV_AUDIO_HDRSIZE     4
#define USBTV_AUDIO_BUFFER      65536

/* Chunk header. */
#define USBTV_MAGIC_OK(chunk)   ((be32_to_cpu(chunk[0]) & 0xff000000) \
                                                        == 0x88000000)
#define USBTV_FRAME_ID(chunk)   ((be32_to_cpu(chunk[0]) & 0x00ff0000) >> 16)
#define USBTV_ODD(chunk)        ((be32_to_cpu(chunk[0]) & 0x0000f000) >> 15)
#define USBTV_CHUNK_NO(chunk)   (be32_to_cpu(chunk[0]) & 0x00000fff)

#define USBTV_TV_STD            (V4L2_STD_525_60 | V4L2_STD_PAL | \
                                 V4L2_STD_PAL_Nc | V4L2_STD_SECAM)

/* parameters for supported TV norms */
struct usbtv_norm_params {
        v4l2_std_id norm;
        int cap_width, cap_height;
};

/* A single videobuf2 frame buffer. */
struct usbtv_buf {
        struct vb2_v4l2_buffer vb;
        struct list_head list;
};

/* Per-device structure. */
struct usbtv {
        struct device *dev;
        struct usb_device *udev;

        /* video */
        struct v4l2_device v4l2_dev;
        struct v4l2_ctrl_handler ctrl;
        struct video_device vdev;
        struct vb2_queue vb2q;
        struct mutex v4l2_lock;
        struct mutex vb2q_lock;

        /* List of videobuf2 buffers protected by a lock. */
        spinlock_t buflock;
        struct list_head bufs;

        /* Number of currently processed frame, useful find
         * out when a new one begins. */
        u32 frame_id;
        int chunks_done;

        enum {
                USBTV_COMPOSITE_INPUT,
                USBTV_SVIDEO_INPUT,
        } input;
        v4l2_std_id norm;
        int width, height;
        int n_chunks;
        int iso_size;
        int last_odd;
        unsigned int sequence;
        struct urb *isoc_urbs[USBTV_ISOC_TRANSFERS];

        /* audio */
        struct snd_card *snd;
        struct snd_pcm_substream *snd_substream;
        atomic_t snd_stream;
        struct work_struct snd_trigger;
        struct urb *snd_bulk_urb;
        size_t snd_buffer_pos;
        size_t snd_period_pos;
};

int usbtv_set_regs(struct usbtv *usbtv, const u16 regs[][2], int size);

int usbtv_video_init(struct usbtv *usbtv);
void usbtv_video_free(struct usbtv *usbtv);

int usbtv_audio_init(struct usbtv *usbtv);
void usbtv_audio_free(struct usbtv *usbtv);
void usbtv_audio_suspend(struct usbtv *usbtv);
void usbtv_audio_resume(struct usbtv *usbtv);