path: root/sound/core/pcm.c

/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
 *
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <sound/driver.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/pcm.h>
#include <sound/control.h>
#include <sound/info.h>

MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>, Abramo Bagnara <abramo@alsa-project.org>");
MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
MODULE_LICENSE("GPL");

struct snd_pcm *snd_pcm_devices[SNDRV_CARDS * SNDRV_PCM_DEVICES];
static LIST_HEAD(snd_pcm_notify_list);
static DECLARE_MUTEX(register_mutex);

static int snd_pcm_free(struct snd_pcm *pcm);
static int snd_pcm_dev_free(struct snd_device *device);
static int snd_pcm_dev_register(struct snd_device *device);
static int snd_pcm_dev_disconnect(struct snd_device *device);
static int snd_pcm_dev_unregister(struct snd_device *device);

static int snd_pcm_control_ioctl(struct snd_card *card,
				 struct snd_ctl_file *control,
				 unsigned int cmd, unsigned long arg)
{
	unsigned int tmp;

	tmp = card->number * SNDRV_PCM_DEVICES;
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
		{
			int device;

			if (get_user(device, (int __user *)arg))
				return -EFAULT;
			device = device < 0 ? 0 : device + 1;
			while (device < SNDRV_PCM_DEVICES) {
				if (snd_pcm_devices[tmp + device])
					break;
				device++;
			}
			if (device == SNDRV_PCM_DEVICES)
				device = -1;
			if (put_user(device, (int __user *)arg))
				return -EFAULT;
			return 0;
		}
	case SNDRV_CTL_IOCTL_PCM_INFO:
		{
			struct snd_pcm_info __user *info;
			unsigned int device, subdevice;
			int stream;
			struct snd_pcm *pcm;
			struct snd_pcm_str *pstr;
			struct snd_pcm_substream *substream;
			info = (struct snd_pcm_info __user *)arg;
			if (get_user(device, &info->device))
				return -EFAULT;
			if (device >= SNDRV_PCM_DEVICES)
				return -ENXIO;
			pcm = snd_pcm_devices[tmp + device];
			if (pcm == NULL)
				return -ENXIO;
			if (get_user(stream, &info->stream))
				return -EFAULT;
			if (stream < 0 || stream > 1)
				return -EINVAL;
			pstr = &pcm->streams[stream];
			if (pstr->substream_count == 0)
				return -ENOENT;
			if (get_user(subdevice, &info->subdevice))
				return -EFAULT;
			if (subdevice >= pstr->substream_count)
				return -ENXIO;
			for (substream = pstr->substream; substream; substream = substream->next)
				if (substream->number == (int)subdevice)
					break;
			if (substream == NULL)
				return -ENXIO;
			return snd_pcm_info_user(substream, info);
		}
	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
		{
			int val;
			
			if (get_user(val, (int __user *)