linux-imx

/*

 * dmxdev.c - DVB demultiplexer device

 *

 * Copyright (C) 2000 Ralph Metzler & Marcus Metzler

 *            for convergence integrated media GmbH

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public License

 * as published by the Free Software Foundation; either version 2.1

 * 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.

 *

 */

​

#define pr_fmt(fmt) "dmxdev: " fmt

​

#include <linux/sched.h>

#include <linux/spinlock.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/module.h>

#include <linux/poll.h>

#include <linux/ioctl.h>

#include <linux/wait.h>

#include <linux/uaccess.h>

#include <media/dmxdev.h>

#include <media/dvb_vb2.h>

​

static int debug;

​

module_param(debug, int, 0644);

MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");

​

#define dprintk(fmt, arg...) do {                   \

    if (debug)                          \

        printk(KERN_DEBUG pr_fmt("%s: " fmt),           \

            __func__, ##arg);               \

} while (0)

​

static int dvb_dmxdev_buffer_write(struct dvb_ringbuffer *buf,

                   const u8 *src, size_t len)

{

    ssize_t free;

​

    if (!len)

        return 0;

    if (!buf->data)

        return 0;

​

    free = dvb_ringbuffer_free(buf);

    if (len > free) {

        dprintk("buffer overflow\n");

        return -EOVERFLOW;

    }

​

    return dvb_ringbuffer_write(buf, src, len);

}

​

static ssize_t dvb_dmxdev_buffer_read(struct dvb_ringbuffer *src,