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root/sound/core/pcm.c

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DEFINITIONS

This source file includes following definitions.
  1. snd_pcm_get
  2. snd_pcm_next
  3. snd_pcm_add
  4. snd_pcm_control_ioctl
  5. snd_pcm_format_name
  6. snd_pcm_stream_name
  7. snd_pcm_access_name
  8. snd_pcm_subformat_name
  9. snd_pcm_tstamp_mode_name
  10. snd_pcm_state_name
  11. snd_pcm_oss_format_name
  12. snd_pcm_proc_info_read
  13. snd_pcm_stream_proc_info_read
  14. snd_pcm_substream_proc_info_read
  15. snd_pcm_substream_proc_hw_params_read
  16. snd_pcm_substream_proc_sw_params_read
  17. snd_pcm_substream_proc_status_read
  18. snd_pcm_xrun_debug_read
  19. snd_pcm_xrun_debug_write
  20. snd_pcm_stream_proc_init
  21. snd_pcm_stream_proc_done
  22. snd_pcm_substream_proc_init
  23. snd_pcm_substream_proc_done
  24. snd_pcm_stream_proc_init
  25. snd_pcm_stream_proc_done
  26. snd_pcm_substream_proc_init
  27. snd_pcm_substream_proc_done
  28. snd_pcm_new_stream
  29. snd_pcm_new
  30. snd_pcm_free_stream
  31. snd_pcm_free
  32. snd_pcm_dev_free
  33. snd_pcm_attach_substream
  34. snd_pcm_detach_substream
  35. show_pcm_class
  36. snd_pcm_dev_register
  37. snd_pcm_dev_disconnect
  38. snd_pcm_notify
  39. snd_pcm_proc_read
  40. snd_pcm_proc_init
  41. snd_pcm_proc_done
  42. alsa_pcm_init
  43. alsa_pcm_exit

/*
 *  Digital Audio (PCM) abstract layer
 *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <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 <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
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_get(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_next(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->device;
                else if (pcm->card->number > card->number)
                        return -1;
        }
        return -1;
}

static int snd_pcm_add(struct snd_pcm *newpcm)
{
        struct snd_pcm *pcm;

        list_for_each_entry(pcm, &snd_pcm_devices, list) {
                if (pcm->card == newpcm->card && pcm->device == newpcm->device)
                        return -EBUSY;
                if (pcm->card->number > newpcm->card->number ||
                                (pcm->card == newpcm->card &&
                                pcm->device > newpcm->device)) {
                        list_add(&newpcm->list, pcm->list.prev);
                        return 0;
                }
        }
        list_add_tail(&newpcm->list, &snd_pcm_devices);
        return 0;
}

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 = snd_pcm_next(card, device);
                        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_get(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(ENABLE),
};

static const char *snd_pcm_stream_name(int stream)
{
        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)
{
        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);        
#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)
{
        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, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
        snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
        snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
        snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
        snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
        snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
        snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
        snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
}

static void snd_pcm_substream_proc_status_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;
        struct snd_pcm_status status;
        int err;
        if (!runtime) {
                snd_iprintf(buffer, "closed\n");
                return;
        }
        memset(&status, 0, sizeof(status));
        err = snd_pcm_status(substream, &status);
        if (err < 0) {
                snd_iprintf(buffer, "error %d\n", err);
                return;
        }
        snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
        snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
                status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
        snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
                status.tstamp.tv_sec, status.tstamp.tv_nsec);
        snd_iprintf(buffer, "delay       : %ld\n", status.delay);
        snd_iprintf(buffer, "avail       : %ld\n", status.avail);
        snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
        snd_iprintf(buffer, "-----\n");
        snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
        snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
}

#ifdef CONFIG_SND_PCM_XRUN_DEBUG
static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
                                    struct snd_info_buffer *buffer)
{
        struct snd_pcm_str *pstr = entry->private_data;
        snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
}

static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
                                     struct snd_info_buffer *buffer)
{
        struct snd_pcm_str *pstr = entry->private_data;
        char line[64];
        if (!snd_info_get_line(buffer, line, sizeof(line)))
                pstr->xrun_debug = simple_strtoul(line, NULL, 10);
}
#endif

static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
{
        struct snd_pcm *pcm = pstr->pcm;
        struct snd_info_entry *entry;
        char name[16];

        sprintf(name, "pcm%i%c", pcm->device, 
                pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
        if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
                return -ENOMEM;
        entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
        if (snd_info_register(entry) < 0) {
                snd_info_free_entry(entry);
                return -ENOMEM;
        }
        pstr->proc_root = entry;

        if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
                snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        pstr->proc_info_entry = entry;

#ifdef CONFIG_SND_PCM_XRUN_DEBUG
        if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
                                                pstr->proc_root)) != NULL) {
                entry->c.text.read = snd_pcm_xrun_debug_read;
                entry->c.text.write = snd_pcm_xrun_debug_write;
                entry->mode |= S_IWUSR;
                entry->private_data = pstr;
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        pstr->proc_xrun_debug_entry = entry;
#endif
        return 0;
}

static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
{
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
        snd_info_free_entry(pstr->proc_xrun_debug_entry);
        pstr->proc_xrun_debug_entry = NULL;
#endif
        snd_info_free_entry(pstr->proc_info_entry);
        pstr->proc_info_entry = NULL;
        snd_info_free_entry(pstr->proc_root);
        pstr->proc_root = NULL;
        return 0;
}

static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
{
        struct snd_info_entry *entry;
        struct snd_card *card;
        char name[16];

        card = substream->pcm->card;

        sprintf(name, "sub%i", substream->number);
        if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
                return -ENOMEM;
        entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
        if (snd_info_register(entry) < 0) {
                snd_info_free_entry(entry);
                return -ENOMEM;
        }
        substream->proc_root = entry;

        if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
                snd_info_set_text_ops(entry, substream,
                                      snd_pcm_substream_proc_info_read);
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        substream->proc_info_entry = entry;

        if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
                snd_info_set_text_ops(entry, substream,
                                      snd_pcm_substream_proc_hw_params_read);
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        substream->proc_hw_params_entry = entry;

        if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
                snd_info_set_text_ops(entry, substream,
                                      snd_pcm_substream_proc_sw_params_read);
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        substream->proc_sw_params_entry = entry;

        if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
                snd_info_set_text_ops(entry, substream,
                                      snd_pcm_substream_proc_status_read);
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        substream->proc_status_entry = entry;

        return 0;
}

static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
{
        snd_info_free_entry(substream->proc_info_entry);
        substream->proc_info_entry = NULL;
        snd_info_free_entry(substream->proc_hw_params_entry);
        substream->proc_hw_params_entry = NULL;
        snd_info_free_entry(substream->proc_sw_params_entry);
        substream->proc_sw_params_entry = NULL;
        snd_info_free_entry(substream->proc_status_entry);
        substream->proc_status_entry = NULL;
        snd_info_free_entry(substream->proc_root);
        substream->proc_root = NULL;
        return 0;
}
#else /* !CONFIG_SND_VERBOSE_PROCFS */
static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
#endif /* CONFIG_SND_VERBOSE_PROCFS */

/**
 * snd_pcm_new_stream - create a new PCM stream
 * @pcm: the pcm instance
 * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 * @substream_count: the number of substreams
 *
 * Creates a new stream for the pcm.
 * The corresponding stream on the pcm must have been empty before
 * calling this, i.e. zero must be given to the argument of
 * snd_pcm_new().
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
{
        int idx, err;
        struct snd_pcm_str *pstr = &pcm->streams[stream];
        struct snd_pcm_substream *substream, *prev;

#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
        mutex_init(&pstr->oss.setup_mutex);
#endif
        pstr->stream = stream;
        pstr->pcm = pcm;
        pstr->substream_count = substream_count;
        if (substream_count > 0) {
                err = snd_pcm_stream_proc_init(pstr);
                if (err < 0) {
                        snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
                        return err;
                }
        }
        prev = NULL;
        for (idx = 0, prev = NULL; idx < substream_count; idx++) {
                substream = kzalloc(sizeof(*substream), GFP_KERNEL);
                if (substream == NULL) {
                        snd_printk(KERN_ERR "Cannot allocate PCM substream\n");
                        return -ENOMEM;
                }
                substream->pcm = pcm;
                substream->pstr = pstr;
                substream->number = idx;
                substream->stream = stream;
                sprintf(substream->name, "subdevice #%i", idx);
                snprintf(substream->latency_id, sizeof(substream->latency_id),
                         "ALSA-PCM%d-%d%c%d", pcm->card->number, pcm->device,
                         (stream ? 'c' : 'p'), idx);
                substream->buffer_bytes_max = UINT_MAX;
                if (prev == NULL)
                        pstr->substream = substream;
                else
                        prev->next = substream;
                err = snd_pcm_substream_proc_init(substream);
                if (err < 0) {
                        snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
                        if (prev == NULL)
                                pstr->substream = NULL;
                        else
                                prev->next = NULL;
                        kfree(substream);
                        return err;
                }
                substream->group = &substream->self_group;
                spin_lock_init(&substream->self_group.lock);
                INIT_LIST_HEAD(&substream->self_group.substreams);
                list_add_tail(&substream->link_list, &substream->self_group.substreams);
                spin_lock_init(&substream->timer_lock);
                atomic_set(&substream->mmap_count, 0);
                prev = substream;
        }
        return 0;
}                               

EXPORT_SYMBOL(snd_pcm_new_stream);

/**
 * snd_pcm_new - create a new PCM instance
 * @card: the card instance
 * @id: the id string
 * @device: the device index (zero based)
 * @playback_count: the number of substreams for playback
 * @capture_count: the number of substreams for capture
 * @rpcm: the pointer to store the new pcm instance
 *
 * Creates a new PCM instance.
 *
 * The pcm operators have to be set afterwards to the new instance
 * via snd_pcm_set_ops().
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_pcm_new(struct snd_card *card, char *id, int device,
                int playback_count, int capture_count,
                struct snd_pcm ** rpcm)
{
        struct snd_pcm *pcm;
        int err;
        static struct snd_device_ops ops = {
                .dev_free = snd_pcm_dev_free,
                .dev_register = snd_pcm_dev_register,
                .dev_disconnect = snd_pcm_dev_disconnect,
        };

        if (snd_BUG_ON(!card))
                return -ENXIO;
        if (rpcm)
                *rpcm = NULL;
        pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
        if (pcm == NULL) {
                snd_printk(KERN_ERR "Cannot allocate PCM\n");
                return -ENOMEM;
        }
        pcm->card = card;
        pcm->device = device;
        if (id)
                strlcpy(pcm->id, id, sizeof(pcm->id));
        if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
                snd_pcm_free(pcm);
                return err;
        }
        if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
                snd_pcm_free(pcm);
                return err;
        }
        mutex_init(&pcm->open_mutex);
        init_waitqueue_head(&pcm->open_wait);
        if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
                snd_pcm_free(pcm);
                return err;
        }
        if (rpcm)
                *rpcm = pcm;
        return 0;
}

EXPORT_SYMBOL(snd_pcm_new);

static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
{
        struct snd_pcm_substream *substream, *substream_next;
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
        struct snd_pcm_oss_setup *setup, *setupn;
#endif
        substream = pstr->substream;
        while (substream) {
                substream_next = substream->next;
                snd_pcm_timer_done(substream);
                snd_pcm_substream_proc_done(substream);
                kfree(substream);
                substream = substream_next;
        }
        snd_pcm_stream_proc_done(pstr);
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
        for (setup = pstr->oss.setup_list; setup; setup = setupn) {
                setupn = setup->next;
                kfree(setup->task_name);
                kfree(setup);
        }
#endif
}

static int snd_pcm_free(struct snd_pcm *pcm)
{
        struct snd_pcm_notify *notify;

        if (!pcm)
                return 0;
        list_for_each_entry(notify, &snd_pcm_notify_list, list) {
                notify->n_unregister(pcm);
        }
        if (pcm->private_free)
                pcm->private_free(pcm);
        snd_pcm_lib_preallocate_free_for_all(pcm);
        snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
        snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
        kfree(pcm);
        return 0;
}

static int snd_pcm_dev_free(struct snd_device *device)
{
        struct snd_pcm *pcm = device->device_data;
        return snd_pcm_free(pcm);
}

int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
                             struct file *file,
                             struct snd_pcm_substream **rsubstream)
{
        struct snd_pcm_str * pstr;
        struct snd_pcm_substream *substream;
        struct snd_pcm_runtime *runtime;
        struct snd_ctl_file *kctl;
        struct snd_card *card;
        int prefer_subdevice = -1;
        size_t size;

        if (snd_BUG_ON(!pcm || !rsubstream))
                return -ENXIO;
        *rsubstream = NULL;
        pstr = &pcm->streams[stream];
        if (pstr->substream == NULL || pstr->substream_count == 0)
                return -ENODEV;

        card = pcm->card;
        read_lock(&card->ctl_files_rwlock);
        list_for_each_entry(kctl, &card->ctl_files, list) {
                if (kctl->pid == current->pid) {
                        prefer_subdevice = kctl->prefer_pcm_subdevice;
                        if (prefer_subdevice != -1)
                                break;
                }
        }
        read_unlock(&card->ctl_files_rwlock);

        switch (stream) {
        case SNDRV_PCM_STREAM_PLAYBACK:
                if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
                        for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
                                if (SUBSTREAM_BUSY(substream))
                                        return -EAGAIN;
                        }
                }
                break;
        case SNDRV_PCM_STREAM_CAPTURE:
                if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
                        for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
                                if (SUBSTREAM_BUSY(substream))
                                        return -EAGAIN;
                        }
                }
                break;
        default:
                return -EINVAL;
        }

        if (file->f_flags & O_APPEND) {
                if (prefer_subdevice < 0) {
                        if (pstr->substream_count > 1)
                                return -EINVAL; /* must be unique */
                        substream = pstr->substream;
                } else {
                        for (substream = pstr->substream; substream;
                             substream = substream->next)
                                if (substream->number == prefer_subdevice)
                                        break;
                }
                if (! substream)
                        return -ENODEV;
                if (! SUBSTREAM_BUSY(substream))
                        return -EBADFD;
                substream->ref_count++;
                *rsubstream = substream;
                return 0;
        }

        if (prefer_subdevice >= 0) {
                for (substream = pstr->substream; substream; substream = substream->next)
                        if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
                                goto __ok;
        }
        for (substream = pstr->substream; substream; substream = substream->next)
                if (!SUBSTREAM_BUSY(substream))
                        break;
      __ok:
        if (substream == NULL)
                return -EAGAIN;

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

        size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
        runtime->status = snd_malloc_pages(size, GFP_KERNEL);
        if (runtime->status == NULL) {
                kfree(runtime);
                return -ENOMEM;
        }
        memset((void*)runtime->status, 0, size);

        size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
        runtime->control = snd_malloc_pages(size, GFP_KERNEL);
        if (runtime->control == NULL) {
                snd_free_pages((void*)runtime->status,
                               PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
                kfree(runtime);
                return -ENOMEM;
        }
        memset((void*)runtime->control, 0, size);

        init_waitqueue_head(&runtime->sleep);

        runtime->status->state = SNDRV_PCM_STATE_OPEN;

        substream->runtime = runtime;
        substream->private_data = pcm->private_data;
        substream->ref_count = 1;
        substream->f_flags = file->f_flags;
        pstr->substream_opened++;
        *rsubstream = substream;
        return 0;
}

void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime;

        if (PCM_RUNTIME_CHECK(substream))
                return;
        runtime = substream->runtime;
        if (runtime->private_free != NULL)
                runtime->private_free(runtime);
        snd_free_pages((void*)runtime->status,
                       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
        snd_free_pages((void*)runtime->control,
                       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
        kfree(runtime->hw_constraints.rules);
        kfree(runtime);
        substream->runtime = NULL;
        substream->pstr->substream_opened--;
}

static ssize_t show_pcm_class(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct snd_pcm *pcm;
        const char *str;
        static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
                [SNDRV_PCM_CLASS_GENERIC] = "generic",
                [SNDRV_PCM_CLASS_MULTI] = "multi",
                [SNDRV_PCM_CLASS_MODEM] = "modem",
                [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
        };

        if (! (pcm = dev_get_drvdata(dev)) ||
            pcm->dev_class > SNDRV_PCM_CLASS_LAST)
                str = "none";
        else
                str = strs[pcm->dev_class];
        return snprintf(buf, PAGE_SIZE, "%s\n", str);
}

static struct device_attribute pcm_attrs =
        __ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);

static int snd_pcm_dev_register(struct snd_device *device)
{
        int cidx, err;
        struct snd_pcm_substream *substream;
        struct snd_pcm_notify *notify;
        char str[16];
        struct snd_pcm *pcm = device->device_data;
        struct device *dev;

        if (snd_BUG_ON(!pcm || !device))
                return -ENXIO;
        mutex_lock(&register_mutex);
        err = snd_pcm_add(pcm);
        if (err) {
                mutex_unlock(&register_mutex);
                return err;
        }
        for (cidx = 0; cidx < 2; cidx++) {
                int devtype = -1;
                if (pcm->streams[cidx].substream == NULL)
                        continue;
                switch (cidx) {
                case SNDRV_PCM_STREAM_PLAYBACK:
                        sprintf(str, "pcmC%iD%ip", pcm->card->number, pcm->device);
                        devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
                        break;
                case SNDRV_PCM_STREAM_CAPTURE:
                        sprintf(str, "pcmC%iD%ic", pcm->card->number, pcm->device);
                        devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
                        break;
                }
                /* device pointer to use, pcm->dev takes precedence if
                 * it is assigned, otherwise fall back to card's device
                 * if possible */
                dev = pcm->dev;
                if (!dev)
                        dev = snd_card_get_device_link(pcm->card);
                /* register pcm */
                err = snd_register_device_for_dev(devtype, pcm->card,
                                                  pcm->device,
                                                  &snd_pcm_f_ops[cidx],
                                                  pcm, str, dev);
                if (err < 0) {
                        list_del(&pcm->list);
                        mutex_unlock(&register_mutex);
                        return err;
                }
                snd_add_device_sysfs_file(devtype, pcm->card, pcm->device,
                                          &pcm_attrs);
                for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
                        snd_pcm_timer_init(substream);
        }

        list_for_each_entry(notify, &snd_pcm_notify_list, list)
                notify->n_register(pcm);

        mutex_unlock(&register_mutex);
        return 0;
}

static int snd_pcm_dev_disconnect(struct snd_device *device)
{
        struct snd_pcm *pcm = device->device_data;
        struct snd_pcm_notify *notify;
        struct snd_pcm_substream *substream;
        int cidx, devtype;

        mutex_lock(&register_mutex);
        if (list_empty(&pcm->list))
                goto unlock;

        list_del_init(&pcm->list);
        for (cidx = 0; cidx < 2; cidx++)
                for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
                        if (substream->runtime)
                                substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
        list_for_each_entry(notify, &snd_pcm_notify_list, list) {
                notify->n_disconnect(pcm);
        }
        for (cidx = 0; cidx < 2; cidx++) {
                devtype = -1;
                switch (cidx) {
                case SNDRV_PCM_STREAM_PLAYBACK:
                        devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
                        break;
                case SNDRV_PCM_STREAM_CAPTURE:
                        devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
                        break;
                }
                snd_unregister_device(devtype, pcm->card, pcm->device);
        }
 unlock:
        mutex_unlock(&register_mutex);
        return 0;
}

int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
{
        struct snd_pcm *pcm;

        if (snd_BUG_ON(!notify ||
                       !notify->n_register ||
                       !notify->n_unregister ||
                       !notify->n_disconnect))
                return -EINVAL;
        mutex_lock(&register_mutex);
        if (nfree) {
                list_del(&notify->list);
                list_for_each_entry(pcm, &snd_pcm_devices, list)
                        notify->n_unregister(pcm);
        } else {
                list_add_tail(&notify->list, &snd_pcm_notify_list);
                list_for_each_entry(pcm, &snd_pcm_devices, list)
                        notify->n_register(pcm);
        }
        mutex_unlock(&register_mutex);
        return 0;
}

EXPORT_SYMBOL(snd_pcm_notify);

#ifdef CONFIG_PROC_FS
/*
 *  Info interface
 */

static void snd_pcm_proc_read(struct snd_info_entry *entry,
                              struct snd_info_buffer *buffer)
{
        struct snd_pcm *pcm;

        mutex_lock(&register_mutex);
        list_for_each_entry(pcm, &snd_pcm_devices, list) {
                snd_iprintf(buffer, "%02i-%02i: %s : %s",
                            pcm->card->number, pcm->device, pcm->id, pcm->name);
                if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
                        snd_iprintf(buffer, " : playback %i",
                                    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
                if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
                        snd_iprintf(buffer, " : capture %i",
                                    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
                snd_iprintf(buffer, "\n");
        }
        mutex_unlock(&register_mutex);
}

static struct snd_info_entry *snd_pcm_proc_entry;

static void snd_pcm_proc_init(void)
{
        struct snd_info_entry *entry;

        if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
                snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
                if (snd_info_register(entry) < 0) {
                        snd_info_free_entry(entry);
                        entry = NULL;
                }
        }
        snd_pcm_proc_entry = entry;
}

static void snd_pcm_proc_done(void)
{
        snd_info_free_entry(snd_pcm_proc_entry);
}

#else /* !CONFIG_PROC_FS */
#define snd_pcm_proc_init()
#define snd_pcm_proc_done()
#endif /* CONFIG_PROC_FS */


/*
 *  ENTRY functions
 */

static int __init alsa_pcm_init(void)
{
        snd_ctl_register_ioctl(snd_pcm_control_ioctl);
        snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
        snd_pcm_proc_init();
        return 0;
}

static void __exit alsa_pcm_exit(void)
{
        snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
        snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
        snd_pcm_proc_done();
}

module_init(alsa_pcm_init)
module_exit(alsa_pcm_exit)

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