pcm.c

linux 内核源代码

/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <[e-mail]>
 *
 *
 *   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 <linux/mutex.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 <[e-mail]>, Abramo Bagnara <[e-mail]>");
MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
MODULE_LICENSE("GPL");

static LIST_HEAD(snd_pcm_devices);
static LIST_HEAD(snd_pcm_notify_list);
static DEFINE_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 struct snd_pcm *snd_pcm_search(struct snd_card *card, int device)
{
	struct snd_pcm *pcm;

	list_for_each_entry(pcm, &snd_pcm_devices, list) {
		if (pcm->card == card && pcm->device == device)
			return pcm;
	}
	return NULL;
}

static int snd_pcm_control_ioctl(struct snd_card *card,
				 struct snd_ctl_file *control,
				 unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
		{
			int device;

			if (get_user(device, (int __user *)arg))
				return -EFAULT;
			mutex_lock(&register_mutex);
			device = device < 0 ? 0 : device + 1;
			while (device < SNDRV_PCM_DEVICES) {
				if (snd_pcm_search(card, device))
					break;
				device++;
			}
			if (device == SNDRV_PCM_DEVICES)
				device = -1;
			mutex_unlock(&register_mutex);
			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;
			int err;

			info = (struct snd_pcm_info __user *)arg;
			if (get_user(device, &info->device))
				return -EFAULT;
			if (get_user(stream, &info->stream))
				return -EFAULT;
			if (stream < 0 || stream > 1)
				return -EINVAL;
			if (get_user(subdevice, &info->subdevice))
				return -EFAULT;
			mutex_lock(&register_mutex);
			pcm = snd_pcm_search(card, device);
			if (pcm == NULL) {
				err = -ENXIO;
				goto _error;
			}
			pstr = &pcm->streams[stream];
			if (pstr->substream_count == 0) {
				err = -ENOENT;
				goto _error;
			}
			if (subdevice >= pstr->substream_count) {
				err = -ENXIO;
				goto _error;
			}
			for (substream = pstr->substream; substream;
			     substream = substream->next)
				if (substream->number == (int)subdevice)
					break;
			if (substream == NULL) {
				err = -ENXIO;
				goto _error;
			}
			err = snd_pcm_info_user(substream, info);
		_error:
			mutex_unlock(&register_mutex);
			return err;
		}
	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
		{
			int val;
			
			if (get_user(val, (int __user *)arg))
				return -EFAULT;
			control->prefer_pcm_subdevice = val;
			return 0;
		}
	}
	return -ENOIOCTLCMD;
}

#ifdef CONFIG_SND_VERBOSE_PROCFS

#define STATE(v) [SNDRV_PCM_STATE_##v] = #v
#define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
#define READY(v) [SNDRV_PCM_READY_##v] = #v
#define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
#define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
#define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
#define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
#define START(v) [SNDRV_PCM_START_##v] = #v
#define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
#define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v 

static char *snd_pcm_format_names[] = {
	FORMAT(S8),
	FORMAT(U8),
	FORMAT(S16_LE),
	FORMAT(S16_BE),
	FORMAT(U16_LE),
	FORMAT(U16_BE),
	FORMAT(S24_LE),
	FORMAT(S24_BE),
	FORMAT(U24_LE),
	FORMAT(U24_BE),
	FORMAT(S32_LE),
	FORMAT(S32_BE),
	FORMAT(U32_LE),
	FORMAT(U32_BE),
	FORMAT(FLOAT_LE),
	FORMAT(FLOAT_BE),
	FORMAT(FLOAT64_LE),
	FORMAT(FLOAT64_BE),
	FORMAT(IEC958_SUBFRAME_LE),
	FORMAT(IEC958_SUBFRAME_BE),
	FORMAT(MU_LAW),
	FORMAT(A_LAW),
	FORMAT(IMA_ADPCM),
	FORMAT(MPEG),
	FORMAT(GSM),
	FORMAT(SPECIAL),
	FORMAT(S24_3LE),
	FORMAT(S24_3BE),
	FORMAT(U24_3LE),
	FORMAT(U24_3BE),
	FORMAT(S20_3LE),
	FORMAT(S20_3BE),
	FORMAT(U20_3LE),
	FORMAT(U20_3BE),
	FORMAT(S18_3LE),
	FORMAT(S18_3BE),
	FORMAT(U18_3LE),
	FORMAT(U18_3BE),
};

static const char *snd_pcm_format_name(snd_pcm_format_t format)
{
	return snd_pcm_format_names[format];
}

static char *snd_pcm_stream_names[] = {
	STREAM(PLAYBACK),
	STREAM(CAPTURE),
};

static char *snd_pcm_state_names[] = {
	STATE(OPEN),
	STATE(SETUP),
	STATE(PREPARED),
	STATE(RUNNING),
	STATE(XRUN),
	STATE(DRAINING),
	STATE(PAUSED),
	STATE(SUSPENDED),
};

static char *snd_pcm_access_names[] = {
	ACCESS(MMAP_INTERLEAVED), 
	ACCESS(MMAP_NONINTERLEAVED),
	ACCESS(MMAP_COMPLEX),
	ACCESS(RW_INTERLEAVED),
	ACCESS(RW_NONINTERLEAVED),
};

static char *snd_pcm_subformat_names[] = {
	SUBFORMAT(STD), 
};

static char *snd_pcm_tstamp_mode_names[] = {
	TSTAMP(NONE),
	TSTAMP(MMAP),
};

static const char *snd_pcm_stream_name(int stream)
{
	snd_assert(stream <= SNDRV_PCM_STREAM_LAST, return NULL);
	return snd_pcm_stream_names[stream];
}

static const char *snd_pcm_access_name(snd_pcm_access_t access)
{
	return snd_pcm_access_names[access];
}

static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
{
	return snd_pcm_subformat_names[subformat];
}

static const char *snd_pcm_tstamp_mode_name(int mode)
{
	snd_assert(mode <= SNDRV_PCM_TSTAMP_LAST, return NULL);
	return snd_pcm_tstamp_mode_names[mode];
}

static const char *snd_pcm_state_name(snd_pcm_state_t state)
{
	return snd_pcm_state_names[state];
}

#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
#include <linux/soundcard.h>

static const char *snd_pcm_oss_format_name(int format)
{
	switch (format) {
	case AFMT_MU_LAW:
		return "MU_LAW";
	case AFMT_A_LAW:
		return "A_LAW";
	case AFMT_IMA_ADPCM:
		return "IMA_ADPCM";
	case AFMT_U8:
		return "U8";
	case AFMT_S16_LE:
		return "S16_LE";
	case AFMT_S16_BE:
		return "S16_BE";
	case AFMT_S8:
		return "S8";
	case AFMT_U16_LE:
		return "U16_LE";
	case AFMT_U16_BE:
		return "U16_BE";
	case AFMT_MPEG:
		return "MPEG";
	default:
		return "unknown";
	}
}
#endif

static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
				   struct snd_info_buffer *buffer)
{
	struct snd_pcm_info *info;
	int err;

	if (! substream)
		return;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (! info) {
		printk(KERN_DEBUG "snd_pcm_proc_info_read: cannot malloc\n");
		return;
	}

	err = snd_pcm_info(substream, info);
	if (err < 0) {
		snd_iprintf(buffer, "error %d\n", err);
		kfree(info);
		return;
	}
	snd_iprintf(buffer, "card: %d\n", info->card);
	snd_iprintf(buffer, "device: %d\n", info->device);
	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
	snd_iprintf(buffer, "id: %s\n", info->id);
	snd_iprintf(buffer, "name: %s\n", info->name);
	snd_iprintf(buffer, "subname: %s\n", info->subname);
	snd_iprintf(buffer, "class: %d\n", info->dev_class);
	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
	kfree(info);
}

static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
					  struct snd_info_buffer *buffer)
{
	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
			       buffer);
}

static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
					     struct snd_info_buffer *buffer)
{
	snd_pcm_proc_info_read((struct snd_pcm_substream *)entry->private_data,
			       buffer);
}

static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
						  struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (!runtime) {
		snd_iprintf(buffer, "closed\n");
		return;
	}
	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
		snd_iprintf(buffer, "no setup\n");
		return;
	}
	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
	snd_iprintf(buffer, "channels: %u\n", runtime->channels);	
	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);	
	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);	
	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);	
	snd_iprintf(buffer, "tick_time: %u\n", runtime->tick_time);
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
	if (substream->oss.oss) {
		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);	
		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
	}
#endif
}

static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
						  struct snd_info_buffer *buffer)