text: /*
   *  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/module.h>
  #include <linux/time.h>
  #include <linux/mutex.h>
  #include <linux/device.h>
  #include <sound/core.h>
  #include <sound/minors.h>
  #include <sound/pcm.h>
  #include <sound/timer.h>
  #include <sound/control.h>
  #include <sound/info.h>
  
  #include "pcm_local.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 DEFINE_MUTEX(register_mutex);
  #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  static LIST_HEAD(snd_pcm_notify_list);
  #endif
  
  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;
  
  	if (newpcm->internal)
  		return 0;
  
  	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;
  			}
  			mutex_lock(&pcm->open_mutex);
  			err = snd_pcm_info_user(substream, info);
  			mutex_unlock(&pcm->open_mutex);
  		_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->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
  			return 0;
  		}
  	}
  	return -ENOIOCTLCMD;
  }
  
  #define FORMAT(v) [SNDRV_PCM_FORMAT_##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),
  	FORMAT(G723_24),
  	FORMAT(G723_24_1B),
  	FORMAT(G723_40),
  	FORMAT(G723_40_1B),
  	FORMAT(DSD_U8),
  	FORMAT(DSD_U16_LE),
  	FORMAT(DSD_U32_LE),
  	FORMAT(DSD_U16_BE),
  	FORMAT(DSD_U32_BE),
  };
  
  /**
   * snd_pcm_format_name - Return a name string for the given PCM format
   * @format: PCM format
   */
  const char *snd_pcm_format_name(snd_pcm_format_t format)
  {
  	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
  		return "Unknown";
  	return snd_pcm_format_names[(__force unsigned int)format];
  }
  EXPORT_SYMBOL_GPL(snd_pcm_format_name);
  
  #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 SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v 
  
  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[(__force int)access];
  }
  
  static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
  {
  	return snd_pcm_subformat_names[(__force int)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[(__force int)state];
  }
  
  #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  #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)
  		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(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;
  
  	mutex_lock(&substream->pcm->open_mutex);
  	runtime = substream->runtime;
  	if (!runtime) {
  		snd_iprintf(buffer, "closed\n");
  		goto unlock;
  	}
  	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
  		snd_iprintf(buffer, "no setup\n");
  		goto unlock;
  	}
  	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 IS_ENABLED(CONFIG_SND_PCM_OSS)
  	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
   unlock:
  	mutex_unlock(&substream->pcm->open_mutex);
  }
  
  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;
  
  	mutex_lock(&substream->pcm->open_mutex);
  	runtime = substream->runtime;
  	if (!runtime) {
  		snd_iprintf(buffer, "closed\n");
  		goto unlock;
  	}
  	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
  		snd_iprintf(buffer, "no setup\n");
  		goto unlock;
  	}
  	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);
   unlock:
  	mutex_unlock(&substream->pcm->open_mutex);
  }
  
  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;
  	struct snd_pcm_status status;
  	int err;
  
  	mutex_lock(&substream->pcm->open_mutex);
  	runtime = substream->runtime;
  	if (!runtime) {
  		snd_iprintf(buffer, "closed\n");
  		goto unlock;
  	}
  	memset(&status, 0, sizeof(status));
  	err = snd_pcm_status(substream, &status);
  	if (err < 0) {
  		snd_iprintf(buffer, "error %d\n", err);
  		goto unlock;
  	}
  	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
  	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
  	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);
   unlock:
  	mutex_unlock(&substream->pcm->open_mutex);
  }
  
  #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
  					 struct snd_info_buffer *buffer)
  {
  	struct snd_pcm_substream *substream = entry->private_data;
  	struct snd_pcm_runtime *runtime;
  
  	snd_pcm_stream_lock_irq(substream);
  	runtime = substream->runtime;
  	if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
  		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
  	snd_pcm_stream_unlock_irq(substream);
  }
  
  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');
  	entry = snd_info_create_card_entry(pcm->card, name,
  					   pcm->card->proc_root);
  	if (!entry)
  		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;
  	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
  	if (entry) {
  		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
  	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
  					   pstr->proc_root);
  	if (entry) {
  		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);
  	entry = snd_info_create_card_entry(card, name,
  					   substream->pstr->proc_root);
  	if (!entry)
  		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;
  	entry = snd_info_create_card_entry(card, "info", substream->proc_root);
  	if (entry) {
  		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;
  	entry = snd_info_create_card_entry(card, "hw_params",
  					   substream->proc_root);
  	if (entry) {
  		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;
  	entry = snd_info_create_card_entry(card, "sw_params",
  					   substream->proc_root);
  	if (entry) {
  		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;
  	entry = snd_info_create_card_entry(card, "status",
  					   substream->proc_root);
  	if (entry) {
  		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;
  
  #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  	entry = snd_info_create_card_entry(card, "xrun_injection",
  					   substream->proc_root);
  	if (entry) {
  		entry->private_data = substream;
  		entry->c.text.read = NULL;
  		entry->c.text.write = snd_pcm_xrun_injection_write;
  		entry->mode = S_IFREG | S_IWUSR;
  		if (snd_info_register(entry) < 0) {
  			snd_info_free_entry(entry);
  			entry = NULL;
  		}
  	}
  	substream->proc_xrun_injection_entry = entry;
  #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
  
  	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;
  #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  	snd_info_free_entry(substream->proc_xrun_injection_entry);
  	substream->proc_xrun_injection_entry = NULL;
  #endif
  	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 */
  
  static const struct attribute_group *pcm_dev_attr_groups[];
  
  /**
   * 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().
   *
   * Return: 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 IS_ENABLED(CONFIG_SND_PCM_OSS)
  	mutex_init(&pstr->oss.setup_mutex);
  #endif
  	pstr->stream = stream;
  	pstr->pcm = pcm;
  	pstr->substream_count = substream_count;
  	if (!substream_count)
  		return 0;
  
  	snd_device_initialize(&pstr->dev, pcm->card);
  	pstr->dev.groups = pcm_dev_attr_groups;
  	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
  		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
  
  	if (!pcm->internal) {
  		err = snd_pcm_stream_proc_init(pstr);
  		if (err < 0) {
  			pcm_err(pcm, "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)
  			return -ENOMEM;
  		substream->pcm = pcm;
  		substream->pstr = pstr;
  		substream->number = idx;
  		substream->stream = stream;
  		sprintf(substream->name, "subdevice #%i", idx);
  		substream->buffer_bytes_max = UINT_MAX;
  		if (prev == NULL)
  			pstr->substream = substream;
  		else
  			prev->next = substream;
  
  		if (!pcm->internal) {
  			err = snd_pcm_substream_proc_init(substream);
  			if (err < 0) {
  				pcm_err(pcm,
  					"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);
  		mutex_init(&substream->self_group.mutex);
  		INIT_LIST_HEAD(&substream->self_group.substreams);
  		list_add_tail(&substream->link_list, &substream->self_group.substreams);
  		atomic_set(&substream->mmap_count, 0);
  		prev = substream;
  	}
  	return 0;
  }				
  EXPORT_SYMBOL(snd_pcm_new_stream);
  
  static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
  		int playback_count, int capture_count, bool internal,
  		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,
  	};
  	static struct snd_device_ops internal_ops = {
  		.dev_free = snd_pcm_dev_free,
  	};
  
  	if (snd_BUG_ON(!card))
  		return -ENXIO;
  	if (rpcm)
  		*rpcm = NULL;
  	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
  	if (!pcm)
  		return -ENOMEM;
  	pcm->card = card;
  	pcm->device = device;
  	pcm->internal = internal;
  	mutex_init(&pcm->open_mutex);
  	init_waitqueue_head(&pcm->open_wait);
  	INIT_LIST_HEAD(&pcm->list);
  	if (id)
  		strlcpy(pcm->id, id, sizeof(pcm->id));
  
  	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
  				 playback_count);
  	if (err < 0)
  		goto free_pcm;
  
  	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
  	if (err < 0)
  		goto free_pcm;
  
  	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
  			     internal ? &internal_ops : &ops);
  	if (err < 0)
  		goto free_pcm;
  
  	if (rpcm)
  		*rpcm = pcm;
  	return 0;
  
  free_pcm:
  	snd_pcm_free(pcm);
  	return err;
  }
  
  /**
   * 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().
   *
   * Return: Zero if successful, or a negative error code on failure.
   */
  int snd_pcm_new(struct snd_card *card, const char *id, int device,
  		int playback_count, int capture_count, struct snd_pcm **rpcm)
  {
  	return _snd_pcm_new(card, id, device, playback_count, capture_count,
  			false, rpcm);
  }
  EXPORT_SYMBOL(snd_pcm_new);
  
  /**
   * snd_pcm_new_internal - create a new internal PCM instance
   * @card: the card instance
   * @id: the id string
   * @device: the device index (zero based - shared with normal PCMs)
   * @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 internal PCM instance with no userspace device or procfs
   * entries. This is used by ASoC Back End PCMs in order to create a PCM that
   * will only be used internally by kernel drivers. i.e. it cannot be opened
   * by userspace. It provides existing ASoC components drivers with a substream
   * and access to any private data.
   *
   * The pcm operators have to be set afterwards to the new instance
   * via snd_pcm_set_ops().
   *
   * Return: Zero if successful, or a negative error code on failure.
   */
  int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
  	int playback_count, int capture_count,
  	struct snd_pcm **rpcm)
  {
  	return _snd_pcm_new(card, id, device, playback_count, capture_count,
  			true, rpcm);
  }
  EXPORT_SYMBOL(snd_pcm_new_internal);
  
  static void free_chmap(struct snd_pcm_str *pstr)
  {
  	if (pstr->chmap_kctl) {
  		snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
  		pstr->chmap_kctl = NULL;
  	}
  }
  
  static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
  {
  	struct snd_pcm_substream *substream, *substream_next;
  #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  	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 IS_ENABLED(CONFIG_SND_PCM_OSS)
  	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
  		setupn = setup->next;
  		kfree(setup->task_name);
  		kfree(setup);
  	}
  #endif
  	free_chmap(pstr);
  	if (pstr->substream_count)
  		put_device(&pstr->dev);
  }
  
  #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  #define pcm_call_notify(pcm, call)					\
  	do {								\
  		struct snd_pcm_notify *_notify;				\
  		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
  			_notify->call(pcm);				\
  	} while (0)
  #else
  #define pcm_call_notify(pcm, call) do {} while (0)
  #endif
  
  static int snd_pcm_free(struct snd_pcm *pcm)
  {
  	if (!pcm)
  		return 0;
  	if (!pcm->internal)
  		pcm_call_notify(pcm, n_unregister);
  	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_card *card;
  	int prefer_subdevice;
  	size_t size;
  
  	if (snd_BUG_ON(!pcm || !rsubstream))
  		return -ENXIO;
  	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
  		       stream != SNDRV_PCM_STREAM_CAPTURE))
  		return -EINVAL;
  	*rsubstream = NULL;
  	pstr = &pcm->streams[stream];
  	if (pstr->substream == NULL || pstr->substream_count == 0)
  		return -ENODEV;
  
  	card = pcm->card;
  	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
  
  	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
  		int opposite = !stream;
  
  		for (substream = pcm->streams[opposite].substream; substream;
  		     substream = substream->next) {
  			if (SUBSTREAM_BUSY(substream))
  				return -EAGAIN;
  		}
  	}
  
  	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;
  	}
  
  	for (substream = pstr->substream; substream; substream = substream->next) {
  		if (!SUBSTREAM_BUSY(substream) &&
  		    (prefer_subdevice == -1 ||
  		     substream->number == prefer_subdevice))
  			break;
  	}
  	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);
  	init_waitqueue_head(&runtime->tsleep);
  
  	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;
  	substream->pid = get_pid(task_pid(current));
  	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);
  	/* Avoid concurrent access to runtime via PCM timer interface */
  	if (substream->timer)
  		spin_lock_irq(&substream->timer->lock);
  	substream->runtime = NULL;
  	if (substream->timer)
  		spin_unlock_irq(&substream->timer->lock);
  	kfree(runtime);
  	put_pid(substream->pid);
  	substream->pid = NULL;
  	substream->pstr->substream_opened--;
  }
  
  static ssize_t show_pcm_class(struct device *dev,
  			      struct device_attribute *attr, char *buf)
  {
  	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
  	struct snd_pcm *pcm = pstr->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_class > SNDRV_PCM_CLASS_LAST)
  		str = "none";
  	else
  		str = strs[pcm->dev_class];
          return snprintf(buf, PAGE_SIZE, "%s\n", str);
  }
  
  static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
  static struct attribute *pcm_dev_attrs[] = {
  	&dev_attr_pcm_class.attr,
  	NULL
  };
  
  static const struct attribute_group pcm_dev_attr_group = {
  	.attrs	= pcm_dev_attrs,
  };
  
  static const struct attribute_group *pcm_dev_attr_groups[] = {
  	&pcm_dev_attr_group,
  	NULL
  };
  
  static int snd_pcm_dev_register(struct snd_device *device)
  {
  	int cidx, err;
  	struct snd_pcm_substream *substream;
  	struct snd_pcm *pcm;
  
  	if (snd_BUG_ON(!device || !device->device_data))
  		return -ENXIO;
  	pcm = device->device_data;
  
  	mutex_lock(&register_mutex);
  	err = snd_pcm_add(pcm);
  	if (err)
  		goto unlock;
  	for (cidx = 0; cidx < 2; cidx++) {
  		int devtype = -1;
  		if (pcm->streams[cidx].substream == NULL)
  			continue;
  		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;
  		}
  		/* register pcm */
  		err = snd_register_device(devtype, pcm->card, pcm->device,
  					  &snd_pcm_f_ops[cidx], pcm,
  					  &pcm->streams[cidx].dev);
  		if (err < 0) {
  			list_del_init(&pcm->list);
  			goto unlock;
  		}
  
  		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
  			snd_pcm_timer_init(substream);
  	}
  
  	pcm_call_notify(pcm, n_register);
  
   unlock:
  	mutex_unlock(&register_mutex);
  	return err;
  }
  
  static int snd_pcm_dev_disconnect(struct snd_device *device)
  {
  	struct snd_pcm *pcm = device->device_data;
  	struct snd_pcm_substream *substream;
  	int cidx;
  
  	mutex_lock(&register_mutex);
  	mutex_lock(&pcm->open_mutex);
  	wake_up(&pcm->open_wait);
  	list_del_init(&pcm->list);
  	for (cidx = 0; cidx < 2; cidx++) {
  		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
  			snd_pcm_stream_lock_irq(substream);
  			if (substream->runtime) {
  				if (snd_pcm_running(substream))
  					snd_pcm_stop(substream,
  						     SNDRV_PCM_STATE_DISCONNECTED);
  				/* to be sure, set the state unconditionally */
  				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
  				wake_up(&substream->runtime->sleep);
  				wake_up(&substream->runtime->tsleep);
  			}
  			snd_pcm_stream_unlock_irq(substream);
  		}
  	}
  
  	pcm_call_notify(pcm, n_disconnect);
  	for (cidx = 0; cidx < 2; cidx++) {
  		snd_unregister_device(&pcm->streams[cidx].dev);
  		free_chmap(&pcm->streams[cidx]);
  	}
  	mutex_unlock(&pcm->open_mutex);
  	mutex_unlock(&register_mutex);
  	return 0;
  }
  
  #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  /**
   * snd_pcm_notify - Add/remove the notify list
   * @notify: PCM notify list
   * @nfree: 0 = register, 1 = unregister
   *
   * This adds the given notifier to the global list so that the callback is
   * called for each registered PCM devices.  This exists only for PCM OSS
   * emulation, so far.
   */
  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);
  #endif /* CONFIG_SND_PCM_OSS */
  
  #ifdef CONFIG_SND_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;
  
  	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
  	if (entry) {
  		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_SND_PROC_FS */
  #define snd_pcm_proc_init()
  #define snd_pcm_proc_done()
  #endif /* CONFIG_SND_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)
  