FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2024-12-21 00:42:16 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
f362f98e7c
linux/include/sound/pcm.h
Jean Pihet cc74998618 PM QoS: Minor clean-ups 
- Misc fixes to improve code readability:
  * rename struct pm_qos_request_list to struct pm_qos_request,
  * rename pm_qos_req parameter to req in internal code,
    consistenly use req in the API parameters,
  * update the in-kernel API callers to the new parameters names,
  * rename of fields names (requests, list, node, constraints)

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Acked-by: markgross <markgross@thegnar.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25 15:35:12 +02:00

1068 lines
37 KiB
C
Raw Blame History

#ifndef __SOUND_PCM_H
#define __SOUND_PCM_H
/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Abramo Bagnara <abramo@alsa-project.org>
*
*
* 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/asound.h>
#include <sound/memalloc.h>
#include <sound/minors.h>
#include <linux/poll.h>
#include <linux/mm.h>
#include <linux/bitops.h>
#include <linux/pm_qos.h>
#define snd_pcm_substream_chip(substream) ((substream)->private_data)
#define snd_pcm_chip(pcm) ((pcm)->private_data)
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
#include "pcm_oss.h"
#endif
/*
* Hardware (lowlevel) section
*/
struct snd_pcm_hardware {
unsigned int info; /* SNDRV_PCM_INFO_* */
u64 formats; /* SNDRV_PCM_FMTBIT_* */
unsigned int rates; /* SNDRV_PCM_RATE_* */
unsigned int rate_min; /* min rate */
unsigned int rate_max; /* max rate */
unsigned int channels_min; /* min channels */
unsigned int channels_max; /* max channels */
size_t buffer_bytes_max; /* max buffer size */
size_t period_bytes_min; /* min period size */
size_t period_bytes_max; /* max period size */
unsigned int periods_min; /* min # of periods */
unsigned int periods_max; /* max # of periods */
size_t fifo_size; /* fifo size in bytes */
};
struct snd_pcm_substream;
struct snd_pcm_ops {
int (*open)(struct snd_pcm_substream *substream);
int (*close)(struct snd_pcm_substream *substream);
int (*ioctl)(struct snd_pcm_substream * substream,
unsigned int cmd, void *arg);
int (*hw_params)(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params);
int (*hw_free)(struct snd_pcm_substream *substream);
int (*prepare)(struct snd_pcm_substream *substream);
int (*trigger)(struct snd_pcm_substream *substream, int cmd);
snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *substream);
int (*copy)(struct snd_pcm_substream *substream, int channel,
snd_pcm_uframes_t pos,
void __user *buf, snd_pcm_uframes_t count);
int (*silence)(struct snd_pcm_substream *substream, int channel,
snd_pcm_uframes_t pos, snd_pcm_uframes_t count);
struct page *(*page)(struct snd_pcm_substream *substream,
unsigned long offset);
int (*mmap)(struct snd_pcm_substream *substream, struct vm_area_struct *vma);
int (*ack)(struct snd_pcm_substream *substream);
};
/*
*
*/
#if defined(CONFIG_SND_DYNAMIC_MINORS)
#define SNDRV_PCM_DEVICES (SNDRV_OS_MINORS-2)
#else
#define SNDRV_PCM_DEVICES 8
#endif
#define SNDRV_PCM_IOCTL1_FALSE ((void *)0)
#define SNDRV_PCM_IOCTL1_TRUE ((void *)1)
#define SNDRV_PCM_IOCTL1_RESET 0
#define SNDRV_PCM_IOCTL1_INFO 1
#define SNDRV_PCM_IOCTL1_CHANNEL_INFO 2
#define SNDRV_PCM_IOCTL1_GSTATE 3
#define SNDRV_PCM_IOCTL1_FIFO_SIZE 4
#define SNDRV_PCM_TRIGGER_STOP 0
#define SNDRV_PCM_TRIGGER_START 1
#define SNDRV_PCM_TRIGGER_PAUSE_PUSH 3
#define SNDRV_PCM_TRIGGER_PAUSE_RELEASE 4
#define SNDRV_PCM_TRIGGER_SUSPEND 5
#define SNDRV_PCM_TRIGGER_RESUME 6
#define SNDRV_PCM_POS_XRUN ((snd_pcm_uframes_t)-1)
/* If you change this don't forget to change rates[] table in pcm_native.c */
#define SNDRV_PCM_RATE_5512 (1<<0) /* 5512Hz */
#define SNDRV_PCM_RATE_8000 (1<<1) /* 8000Hz */
#define SNDRV_PCM_RATE_11025 (1<<2) /* 11025Hz */
#define SNDRV_PCM_RATE_16000 (1<<3) /* 16000Hz */
#define SNDRV_PCM_RATE_22050 (1<<4) /* 22050Hz */
#define SNDRV_PCM_RATE_32000 (1<<5) /* 32000Hz */
#define SNDRV_PCM_RATE_44100 (1<<6) /* 44100Hz */
#define SNDRV_PCM_RATE_48000 (1<<7) /* 48000Hz */
#define SNDRV_PCM_RATE_64000 (1<<8) /* 64000Hz */
#define SNDRV_PCM_RATE_88200 (1<<9) /* 88200Hz */
#define SNDRV_PCM_RATE_96000 (1<<10) /* 96000Hz */
#define SNDRV_PCM_RATE_176400 (1<<11) /* 176400Hz */
#define SNDRV_PCM_RATE_192000 (1<<12) /* 192000Hz */
#define SNDRV_PCM_RATE_CONTINUOUS (1<<30) /* continuous range */
#define SNDRV_PCM_RATE_KNOT (1<<31) /* supports more non-continuos rates */
#define SNDRV_PCM_RATE_8000_44100 (SNDRV_PCM_RATE_8000|SNDRV_PCM_RATE_11025|\
SNDRV_PCM_RATE_16000|SNDRV_PCM_RATE_22050|\
SNDRV_PCM_RATE_32000|SNDRV_PCM_RATE_44100)
#define SNDRV_PCM_RATE_8000_48000 (SNDRV_PCM_RATE_8000_44100|SNDRV_PCM_RATE_48000)
#define SNDRV_PCM_RATE_8000_96000 (SNDRV_PCM_RATE_8000_48000|SNDRV_PCM_RATE_64000|\
SNDRV_PCM_RATE_88200|SNDRV_PCM_RATE_96000)
#define SNDRV_PCM_RATE_8000_192000 (SNDRV_PCM_RATE_8000_96000|SNDRV_PCM_RATE_176400|\
SNDRV_PCM_RATE_192000)
#define _SNDRV_PCM_FMTBIT(fmt) (1ULL << (__force int)SNDRV_PCM_FORMAT_##fmt)
#define SNDRV_PCM_FMTBIT_S8 _SNDRV_PCM_FMTBIT(S8)
#define SNDRV_PCM_FMTBIT_U8 _SNDRV_PCM_FMTBIT(U8)
#define SNDRV_PCM_FMTBIT_S16_LE _SNDRV_PCM_FMTBIT(S16_LE)
#define SNDRV_PCM_FMTBIT_S16_BE _SNDRV_PCM_FMTBIT(S16_BE)
#define SNDRV_PCM_FMTBIT_U16_LE _SNDRV_PCM_FMTBIT(U16_LE)
#define SNDRV_PCM_FMTBIT_U16_BE _SNDRV_PCM_FMTBIT(U16_BE)
#define SNDRV_PCM_FMTBIT_S24_LE _SNDRV_PCM_FMTBIT(S24_LE)
#define SNDRV_PCM_FMTBIT_S24_BE _SNDRV_PCM_FMTBIT(S24_BE)
#define SNDRV_PCM_FMTBIT_U24_LE _SNDRV_PCM_FMTBIT(U24_LE)
#define SNDRV_PCM_FMTBIT_U24_BE _SNDRV_PCM_FMTBIT(U24_BE)
#define SNDRV_PCM_FMTBIT_S32_LE _SNDRV_PCM_FMTBIT(S32_LE)
#define SNDRV_PCM_FMTBIT_S32_BE _SNDRV_PCM_FMTBIT(S32_BE)
#define SNDRV_PCM_FMTBIT_U32_LE _SNDRV_PCM_FMTBIT(U32_LE)
#define SNDRV_PCM_FMTBIT_U32_BE _SNDRV_PCM_FMTBIT(U32_BE)
#define SNDRV_PCM_FMTBIT_FLOAT_LE _SNDRV_PCM_FMTBIT(FLOAT_LE)
#define SNDRV_PCM_FMTBIT_FLOAT_BE _SNDRV_PCM_FMTBIT(FLOAT_BE)
#define SNDRV_PCM_FMTBIT_FLOAT64_LE _SNDRV_PCM_FMTBIT(FLOAT64_LE)
#define SNDRV_PCM_FMTBIT_FLOAT64_BE _SNDRV_PCM_FMTBIT(FLOAT64_BE)
#define SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE _SNDRV_PCM_FMTBIT(IEC958_SUBFRAME_LE)
#define SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE _SNDRV_PCM_FMTBIT(IEC958_SUBFRAME_BE)
#define SNDRV_PCM_FMTBIT_MU_LAW _SNDRV_PCM_FMTBIT(MU_LAW)
#define SNDRV_PCM_FMTBIT_A_LAW _SNDRV_PCM_FMTBIT(A_LAW)
#define SNDRV_PCM_FMTBIT_IMA_ADPCM _SNDRV_PCM_FMTBIT(IMA_ADPCM)
#define SNDRV_PCM_FMTBIT_MPEG _SNDRV_PCM_FMTBIT(MPEG)
#define SNDRV_PCM_FMTBIT_GSM _SNDRV_PCM_FMTBIT(GSM)
#define SNDRV_PCM_FMTBIT_SPECIAL _SNDRV_PCM_FMTBIT(SPECIAL)
#define SNDRV_PCM_FMTBIT_S24_3LE _SNDRV_PCM_FMTBIT(S24_3LE)
#define SNDRV_PCM_FMTBIT_U24_3LE _SNDRV_PCM_FMTBIT(U24_3LE)
#define SNDRV_PCM_FMTBIT_S24_3BE _SNDRV_PCM_FMTBIT(S24_3BE)
#define SNDRV_PCM_FMTBIT_U24_3BE _SNDRV_PCM_FMTBIT(U24_3BE)
#define SNDRV_PCM_FMTBIT_S20_3LE _SNDRV_PCM_FMTBIT(S20_3LE)
#define SNDRV_PCM_FMTBIT_U20_3LE _SNDRV_PCM_FMTBIT(U20_3LE)
#define SNDRV_PCM_FMTBIT_S20_3BE _SNDRV_PCM_FMTBIT(S20_3BE)
#define SNDRV_PCM_FMTBIT_U20_3BE _SNDRV_PCM_FMTBIT(U20_3BE)
#define SNDRV_PCM_FMTBIT_S18_3LE _SNDRV_PCM_FMTBIT(S18_3LE)
#define SNDRV_PCM_FMTBIT_U18_3LE _SNDRV_PCM_FMTBIT(U18_3LE)
#define SNDRV_PCM_FMTBIT_S18_3BE _SNDRV_PCM_FMTBIT(S18_3BE)
#define SNDRV_PCM_FMTBIT_U18_3BE _SNDRV_PCM_FMTBIT(U18_3BE)
#define SNDRV_PCM_FMTBIT_G723_24 _SNDRV_PCM_FMTBIT(G723_24)
#define SNDRV_PCM_FMTBIT_G723_24_1B _SNDRV_PCM_FMTBIT(G723_24_1B)
#define SNDRV_PCM_FMTBIT_G723_40 _SNDRV_PCM_FMTBIT(G723_40)
#define SNDRV_PCM_FMTBIT_G723_40_1B _SNDRV_PCM_FMTBIT(G723_40_1B)
#ifdef SNDRV_LITTLE_ENDIAN
#define SNDRV_PCM_FMTBIT_S16 SNDRV_PCM_FMTBIT_S16_LE
#define SNDRV_PCM_FMTBIT_U16 SNDRV_PCM_FMTBIT_U16_LE
#define SNDRV_PCM_FMTBIT_S24 SNDRV_PCM_FMTBIT_S24_LE
#define SNDRV_PCM_FMTBIT_U24 SNDRV_PCM_FMTBIT_U24_LE
#define SNDRV_PCM_FMTBIT_S32 SNDRV_PCM_FMTBIT_S32_LE
#define SNDRV_PCM_FMTBIT_U32 SNDRV_PCM_FMTBIT_U32_LE
#define SNDRV_PCM_FMTBIT_FLOAT SNDRV_PCM_FMTBIT_FLOAT_LE
#define SNDRV_PCM_FMTBIT_FLOAT64 SNDRV_PCM_FMTBIT_FLOAT64_LE
#define SNDRV_PCM_FMTBIT_IEC958_SUBFRAME SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE
#endif
#ifdef SNDRV_BIG_ENDIAN
#define SNDRV_PCM_FMTBIT_S16 SNDRV_PCM_FMTBIT_S16_BE
#define SNDRV_PCM_FMTBIT_U16 SNDRV_PCM_FMTBIT_U16_BE
#define SNDRV_PCM_FMTBIT_S24 SNDRV_PCM_FMTBIT_S24_BE
#define SNDRV_PCM_FMTBIT_U24 SNDRV_PCM_FMTBIT_U24_BE
#define SNDRV_PCM_FMTBIT_S32 SNDRV_PCM_FMTBIT_S32_BE
#define SNDRV_PCM_FMTBIT_U32 SNDRV_PCM_FMTBIT_U32_BE
#define SNDRV_PCM_FMTBIT_FLOAT SNDRV_PCM_FMTBIT_FLOAT_BE
#define SNDRV_PCM_FMTBIT_FLOAT64 SNDRV_PCM_FMTBIT_FLOAT64_BE
#define SNDRV_PCM_FMTBIT_IEC958_SUBFRAME SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE
#endif
struct snd_pcm_file {
struct snd_pcm_substream *substream;
int no_compat_mmap;
};
struct snd_pcm_hw_rule;
typedef int (*snd_pcm_hw_rule_func_t)(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule);
struct snd_pcm_hw_rule {
unsigned int cond;
snd_pcm_hw_rule_func_t func;
int var;
int deps[4];
void *private;
};
struct snd_pcm_hw_constraints {
struct snd_mask masks[SNDRV_PCM_HW_PARAM_LAST_MASK -
SNDRV_PCM_HW_PARAM_FIRST_MASK + 1];
struct snd_interval intervals[SNDRV_PCM_HW_PARAM_LAST_INTERVAL -
SNDRV_PCM_HW_PARAM_FIRST_INTERVAL + 1];
unsigned int rules_num;
unsigned int rules_all;
struct snd_pcm_hw_rule *rules;
};
static inline struct snd_mask *constrs_mask(struct snd_pcm_hw_constraints *constrs,
snd_pcm_hw_param_t var)
{
return &constrs->masks[var - SNDRV_PCM_HW_PARAM_FIRST_MASK];
}
static inline struct snd_interval *constrs_interval(struct snd_pcm_hw_constraints *constrs,
snd_pcm_hw_param_t var)
{
return &constrs->intervals[var - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
}
struct snd_ratnum {
unsigned int num;
unsigned int den_min, den_max, den_step;
};
struct snd_ratden {
unsigned int num_min, num_max, num_step;
unsigned int den;
};
struct snd_pcm_hw_constraint_ratnums {
int nrats;
struct snd_ratnum *rats;
};
struct snd_pcm_hw_constraint_ratdens {
int nrats;
struct snd_ratden *rats;
};
struct snd_pcm_hw_constraint_list {
unsigned int count;
unsigned int *list;
unsigned int mask;
};
struct snd_pcm_hwptr_log;
struct snd_pcm_runtime {
/* -- Status -- */
struct snd_pcm_substream *trigger_master;
struct timespec trigger_tstamp; /* trigger timestamp */
int overrange;
snd_pcm_uframes_t avail_max;
snd_pcm_uframes_t hw_ptr_base; /* Position at buffer restart */
snd_pcm_uframes_t hw_ptr_interrupt; /* Position at interrupt time */
unsigned long hw_ptr_jiffies; /* Time when hw_ptr is updated */
unsigned long hw_ptr_buffer_jiffies; /* buffer time in jiffies */
snd_pcm_sframes_t delay; /* extra delay; typically FIFO size */
/* -- HW params -- */
snd_pcm_access_t access; /* access mode */
snd_pcm_format_t format; /* SNDRV_PCM_FORMAT_* */
snd_pcm_subformat_t subformat; /* subformat */
unsigned int rate; /* rate in Hz */
unsigned int channels; /* channels */
snd_pcm_uframes_t period_size; /* period size */
unsigned int periods; /* periods */
snd_pcm_uframes_t buffer_size; /* buffer size */
snd_pcm_uframes_t min_align; /* Min alignment for the format */
size_t byte_align;
unsigned int frame_bits;
unsigned int sample_bits;
unsigned int info;
unsigned int rate_num;
unsigned int rate_den;
unsigned int no_period_wakeup: 1;
/* -- SW params -- */
int tstamp_mode; /* mmap timestamp is updated */
unsigned int period_step;
snd_pcm_uframes_t start_threshold;
snd_pcm_uframes_t stop_threshold;
snd_pcm_uframes_t silence_threshold; /* Silence filling happens when
noise is nearest than this */
snd_pcm_uframes_t silence_size; /* Silence filling size */
snd_pcm_uframes_t boundary; /* pointers wrap point */
snd_pcm_uframes_t silence_start; /* starting pointer to silence area */
snd_pcm_uframes_t silence_filled; /* size filled with silence */
union snd_pcm_sync_id sync; /* hardware synchronization ID */
/* -- mmap -- */
struct snd_pcm_mmap_status *status;
struct snd_pcm_mmap_control *control;
/* -- locking / scheduling -- */
snd_pcm_uframes_t twake; /* do transfer (!poll) wakeup if non-zero */
wait_queue_head_t sleep; /* poll sleep */
wait_queue_head_t tsleep; /* transfer sleep */
struct fasync_struct *fasync;
/* -- private section -- */
void *private_data;
void (*private_free)(struct snd_pcm_runtime *runtime);
/* -- hardware description -- */
struct snd_pcm_hardware hw;
struct snd_pcm_hw_constraints hw_constraints;
/* -- interrupt callbacks -- */
void (*transfer_ack_begin)(struct snd_pcm_substream *substream);
void (*transfer_ack_end)(struct snd_pcm_substream *substream);
/* -- timer -- */
unsigned int timer_resolution; /* timer resolution */
int tstamp_type; /* timestamp type */
/* -- DMA -- */
unsigned char *dma_area; /* DMA area */
dma_addr_t dma_addr; /* physical bus address (not accessible from main CPU) */
size_t dma_bytes; /* size of DMA area */
struct snd_dma_buffer *dma_buffer_p; /* allocated buffer */
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
/* -- OSS things -- */
struct snd_pcm_oss_runtime oss;
#endif
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
struct snd_pcm_hwptr_log *hwptr_log;
#endif
};
struct snd_pcm_group { /* keep linked substreams */
spinlock_t lock;
struct list_head substreams;
int count;
};
struct pid;
struct snd_pcm_substream {
struct snd_pcm *pcm;
struct snd_pcm_str *pstr;
void *private_data; /* copied from pcm->private_data */
int number;
char name[32]; /* substream name */
int stream; /* stream (direction) */
struct pm_qos_request latency_pm_qos_req; /* pm_qos request */
size_t buffer_bytes_max; /* limit ring buffer size */
struct snd_dma_buffer dma_buffer;
unsigned int dma_buf_id;
size_t dma_max;
/* -- hardware operations -- */
struct snd_pcm_ops *ops;
/* -- runtime information -- */
struct snd_pcm_runtime *runtime;
/* -- timer section -- */
struct snd_timer *timer; /* timer */
unsigned timer_running: 1; /* time is running */
/* -- next substream -- */
struct snd_pcm_substream *next;
/* -- linked substreams -- */
struct list_head link_list; /* linked list member */
struct snd_pcm_group self_group; /* fake group for non linked substream (with substream lock inside) */
struct snd_pcm_group *group; /* pointer to current group */
/* -- assigned files -- */
void *file;
int ref_count;
atomic_t mmap_count;
unsigned int f_flags;
void (*pcm_release)(struct snd_pcm_substream *);
struct pid *pid;
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
/* -- OSS things -- */
struct snd_pcm_oss_substream oss;
#endif
#ifdef CONFIG_SND_VERBOSE_PROCFS
struct snd_info_entry *proc_root;
struct snd_info_entry *proc_info_entry;
struct snd_info_entry *proc_hw_params_entry;
struct snd_info_entry *proc_sw_params_entry;
struct snd_info_entry *proc_status_entry;
struct snd_info_entry *proc_prealloc_entry;
struct snd_info_entry *proc_prealloc_max_entry;
#endif
/* misc flags */
unsigned int hw_opened: 1;
};
#define SUBSTREAM_BUSY(substream) ((substream)->ref_count > 0)
struct snd_pcm_str {
int stream; /* stream (direction) */
struct snd_pcm *pcm;
/* -- substreams -- */
unsigned int substream_count;
unsigned int substream_opened;
struct snd_pcm_substream *substream;
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
/* -- OSS things -- */
struct snd_pcm_oss_stream oss;
#endif
#ifdef CONFIG_SND_VERBOSE_PROCFS
struct snd_info_entry *proc_root;
struct snd_info_entry *proc_info_entry;
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
unsigned int xrun_debug; /* 0 = disabled, 1 = verbose, 2 = stacktrace */
struct snd_info_entry *proc_xrun_debug_entry;
#endif
#endif
};
struct snd_pcm {
struct snd_card *card;
struct list_head list;
int device; /* device number */
unsigned int info_flags;
unsigned short dev_class;
unsigned short dev_subclass;
char id[64];
char name[80];
struct snd_pcm_str streams[2];
struct mutex open_mutex;
wait_queue_head_t open_wait;
void *private_data;
void (*private_free) (struct snd_pcm *pcm);
struct device *dev; /* actual hw device this belongs to */
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
struct snd_pcm_oss oss;
#endif
};
struct snd_pcm_notify {
int (*n_register) (struct snd_pcm * pcm);
int (*n_disconnect) (struct snd_pcm * pcm);
int (*n_unregister) (struct snd_pcm * pcm);
struct list_head list;
};
/*
* Registering
*/
extern const struct file_operations snd_pcm_f_ops[2];
int snd_pcm_new(struct snd_card *card, const char *id, int device,
int playback_count, int capture_count,
struct snd_pcm **rpcm);
int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count);
int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree);
/*
* Native I/O
*/
extern rwlock_t snd_pcm_link_rwlock;
int snd_pcm_info(struct snd_pcm_substream *substream, struct snd_pcm_info *info);
int snd_pcm_info_user(struct snd_pcm_substream *substream,
struct snd_pcm_info __user *info);
int snd_pcm_status(struct snd_pcm_substream *substream,
struct snd_pcm_status *status);
int snd_pcm_start(struct snd_pcm_substream *substream);
int snd_pcm_stop(struct snd_pcm_substream *substream, snd_pcm_state_t status);
int snd_pcm_drain_done(struct snd_pcm_substream *substream);
#ifdef CONFIG_PM
int snd_pcm_suspend(struct snd_pcm_substream *substream);
int snd_pcm_suspend_all(struct snd_pcm *pcm);
#endif
int snd_pcm_kernel_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg);
int snd_pcm_open_substream(struct snd_pcm *pcm, int stream, struct file *file,
struct snd_pcm_substream **rsubstream);
void snd_pcm_release_substream(struct snd_pcm_substream *substream);
int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, struct file *file,
struct snd_pcm_substream **rsubstream);
void snd_pcm_detach_substream(struct snd_pcm_substream *substream);
void snd_pcm_vma_notify_data(void *client, void *data);
int snd_pcm_mmap_data(struct snd_pcm_substream *substream, struct file *file, struct vm_area_struct *area);
#ifdef CONFIG_SND_DEBUG
void snd_pcm_debug_name(struct snd_pcm_substream *substream,
char *name, size_t len);
#else
static inline void
snd_pcm_debug_name(struct snd_pcm_substream *substream, char *buf, size_t size)
{
*buf = 0;
}
#endif
/*
* PCM library
*/
static inline int snd_pcm_stream_linked(struct snd_pcm_substream *substream)
{
return substream->group != &substream->self_group;
}
static inline void snd_pcm_stream_lock(struct snd_pcm_substream *substream)
{
read_lock(&snd_pcm_link_rwlock);
spin_lock(&substream->self_group.lock);
}
static inline void snd_pcm_stream_unlock(struct snd_pcm_substream *substream)
{
spin_unlock(&substream->self_group.lock);
read_unlock(&snd_pcm_link_rwlock);
}
static inline void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream)
{
read_lock_irq(&snd_pcm_link_rwlock);
spin_lock(&substream->self_group.lock);
}
static inline void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream)
{
spin_unlock(&substream->self_group.lock);
read_unlock_irq(&snd_pcm_link_rwlock);
}
#define snd_pcm_stream_lock_irqsave(substream, flags) \
do { \
read_lock_irqsave(&snd_pcm_link_rwlock, (flags)); \
spin_lock(&substream->self_group.lock); \
} while (0)
#define snd_pcm_stream_unlock_irqrestore(substream, flags) \
do { \
spin_unlock(&substream->self_group.lock); \
read_unlock_irqrestore(&snd_pcm_link_rwlock, (flags)); \
} while (0)
#define snd_pcm_group_for_each_entry(s, substream) \
list_for_each_entry(s, &substream->group->substreams, link_list)
static inline int snd_pcm_running(struct snd_pcm_substream *substream)
{
return (substream->runtime->status->state == SNDRV_PCM_STATE_RUNNING ||
(substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
substream->stream == SNDRV_PCM_STREAM_PLAYBACK));
}
static inline ssize_t bytes_to_samples(struct snd_pcm_runtime *runtime, ssize_t size)
{
return size * 8 / runtime->sample_bits;
}
static inline snd_pcm_sframes_t bytes_to_frames(struct snd_pcm_runtime *runtime, ssize_t size)
{
return size * 8 / runtime->frame_bits;
}
static inline ssize_t samples_to_bytes(struct snd_pcm_runtime *runtime, ssize_t size)
{
return size * runtime->sample_bits / 8;
}
static inline ssize_t frames_to_bytes(struct snd_pcm_runtime *runtime, snd_pcm_sframes_t size)
{
return size * runtime->frame_bits / 8;
}
static inline int frame_aligned(struct snd_pcm_runtime *runtime, ssize_t bytes)
{
return bytes % runtime->byte_align == 0;
}
static inline size_t snd_pcm_lib_buffer_bytes(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return frames_to_bytes(runtime, runtime->buffer_size);
}
static inline size_t snd_pcm_lib_period_bytes(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return frames_to_bytes(runtime, runtime->period_size);
}
/*
* result is: 0 ... (boundary - 1)
*/
static inline snd_pcm_uframes_t snd_pcm_playback_avail(struct snd_pcm_runtime *runtime)
{
snd_pcm_sframes_t avail = runtime->status->hw_ptr + runtime->buffer_size - runtime->control->appl_ptr;
if (avail < 0)
avail += runtime->boundary;
else if ((snd_pcm_uframes_t) avail >= runtime->boundary)
avail -= runtime->boundary;
return avail;
}
/*
* result is: 0 ... (boundary - 1)
*/
static inline snd_pcm_uframes_t snd_pcm_capture_avail(struct snd_pcm_runtime *runtime)
{
snd_pcm_sframes_t avail = runtime->status->hw_ptr - runtime->control->appl_ptr;
if (avail < 0)
avail += runtime->boundary;
return avail;
}
static inline snd_pcm_sframes_t snd_pcm_playback_hw_avail(struct snd_pcm_runtime *runtime)
{
return runtime->buffer_size - snd_pcm_playback_avail(runtime);
}
static inline snd_pcm_sframes_t snd_pcm_capture_hw_avail(struct snd_pcm_runtime *runtime)
{
return runtime->buffer_size - snd_pcm_capture_avail(runtime);
}
/**
* snd_pcm_playback_ready - check whether the playback buffer is available
* @substream: the pcm substream instance
*
* Checks whether enough free space is available on the playback buffer.
*
* Returns non-zero if available, or zero if not.
*/
static inline int snd_pcm_playback_ready(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return snd_pcm_playback_avail(runtime) >= runtime->control->avail_min;
}
/**
* snd_pcm_capture_ready - check whether the capture buffer is available
* @substream: the pcm substream instance
*
* Checks whether enough capture data is available on the capture buffer.
*
* Returns non-zero if available, or zero if not.
*/
static inline int snd_pcm_capture_ready(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return snd_pcm_capture_avail(runtime) >= runtime->control->avail_min;
}
/**
* snd_pcm_playback_data - check whether any data exists on the playback buffer
* @substream: the pcm substream instance
*
* Checks whether any data exists on the playback buffer. If stop_threshold
* is bigger or equal to boundary, then this function returns always non-zero.
*
* Returns non-zero if exists, or zero if not.
*/
static inline int snd_pcm_playback_data(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
if (runtime->stop_threshold >= runtime->boundary)
return 1;
return snd_pcm_playback_avail(runtime) < runtime->buffer_size;
}
/**
* snd_pcm_playback_empty - check whether the playback buffer is empty
* @substream: the pcm substream instance
*
* Checks whether the playback buffer is empty.
*
* Returns non-zero if empty, or zero if not.
*/
static inline int snd_pcm_playback_empty(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return snd_pcm_playback_avail(runtime) >= runtime->buffer_size;
}
/**
* snd_pcm_capture_empty - check whether the capture buffer is empty
* @substream: the pcm substream instance
*
* Checks whether the capture buffer is empty.
*
* Returns non-zero if empty, or zero if not.
*/
static inline int snd_pcm_capture_empty(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
return snd_pcm_capture_avail(runtime) == 0;
}
static inline void snd_pcm_trigger_done(struct snd_pcm_substream *substream,
struct snd_pcm_substream *master)
{
substream->runtime->trigger_master = master;
}
static inline int hw_is_mask(int var)
{
return var >= SNDRV_PCM_HW_PARAM_FIRST_MASK &&
var <= SNDRV_PCM_HW_PARAM_LAST_MASK;
}
static inline int hw_is_interval(int var)
{
return var >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL &&
var <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL;
}
static inline struct snd_mask *hw_param_mask(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
return &params->masks[var - SNDRV_PCM_HW_PARAM_FIRST_MASK];
}
static inline struct snd_interval *hw_param_interval(struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
return &params->intervals[var - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
}
static inline const struct snd_mask *hw_param_mask_c(const struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
return &params->masks[var - SNDRV_PCM_HW_PARAM_FIRST_MASK];
}
static inline const struct snd_interval *hw_param_interval_c(const struct snd_pcm_hw_params *params,
snd_pcm_hw_param_t var)
{
return &params->intervals[var - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
}
#define params_channels(p) \
(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_CHANNELS)->min)
#define params_rate(p) \
(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_RATE)->min)
#define params_period_size(p) \
(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_PERIOD_SIZE)->min)
#define params_periods(p) \
(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_PERIODS)->min)
#define params_buffer_size(p) \
(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_BUFFER_SIZE)->min)
#define params_buffer_bytes(p) \
(hw_param_interval_c((p), SNDRV_PCM_HW_PARAM_BUFFER_BYTES)->min)
int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v);
void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c);
void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c);
void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
unsigned int k, struct snd_interval *c);
void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
const struct snd_interval *b, struct snd_interval *c);
int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask);
int snd_interval_ratnum(struct snd_interval *i,
unsigned int rats_count, struct snd_ratnum *rats,
unsigned int *nump, unsigned int *denp);
void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params);
void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var);
int snd_pcm_hw_params_choose(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params);
int snd_pcm_hw_refine(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params);
int snd_pcm_hw_constraints_init(struct snd_pcm_substream *substream);
int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream);
int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
u_int32_t mask);
int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
u_int64_t mask);
int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
unsigned int min, unsigned int max);
int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var);
int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
struct snd_pcm_hw_constraint_list *l);
int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
struct snd_pcm_hw_constraint_ratnums *r);
int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
struct snd_pcm_hw_constraint_ratdens *r);
int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
unsigned int cond,
unsigned int width,
unsigned int msbits);
int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var,
unsigned long step);
int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
unsigned int cond,
snd_pcm_hw_param_t var);
int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime,
unsigned int cond,
int var,
snd_pcm_hw_rule_func_t func, void *private,
int dep, ...);
int snd_pcm_format_signed(snd_pcm_format_t format);
int snd_pcm_format_unsigned(snd_pcm_format_t format);
int snd_pcm_format_linear(snd_pcm_format_t format);
int snd_pcm_format_little_endian(snd_pcm_format_t format);
int snd_pcm_format_big_endian(snd_pcm_format_t format);
#if 0 /* just for DocBook */
/**
* snd_pcm_format_cpu_endian - Check the PCM format is CPU-endian
* @format: the format to check
*
* Returns 1 if the given PCM format is CPU-endian, 0 if
* opposite, or a negative error code if endian not specified.
*/
int snd_pcm_format_cpu_endian(snd_pcm_format_t format);
#endif /* DocBook */
#ifdef SNDRV_LITTLE_ENDIAN
#define snd_pcm_format_cpu_endian(format) snd_pcm_format_little_endian(format)
#else
#define snd_pcm_format_cpu_endian(format) snd_pcm_format_big_endian(format)
#endif
int snd_pcm_format_width(snd_pcm_format_t format); /* in bits */
int snd_pcm_format_physical_width(snd_pcm_format_t format); /* in bits */
ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples);
const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format);
int snd_pcm_format_set_silence(snd_pcm_format_t format, void *buf, unsigned int frames);
snd_pcm_format_t snd_pcm_build_linear_format(int width, int unsignd, int big_endian);
void snd_pcm_set_ops(struct snd_pcm * pcm, int direction, struct snd_pcm_ops *ops);
void snd_pcm_set_sync(struct snd_pcm_substream *substream);
int snd_pcm_lib_interleave_len(struct snd_pcm_substream *substream);
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
unsigned int cmd, void *arg);
int snd_pcm_update_state(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime);
int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream);
int snd_pcm_playback_xrun_check(struct snd_pcm_substream *substream);
int snd_pcm_capture_xrun_check(struct snd_pcm_substream *substream);
int snd_pcm_playback_xrun_asap(struct snd_pcm_substream *substream);
int snd_pcm_capture_xrun_asap(struct snd_pcm_substream *substream);
void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr);
void snd_pcm_period_elapsed(struct snd_pcm_substream *substream);
snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream,
const void __user *buf,
snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream,
void __user *buf, snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
void __user **bufs, snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
void __user **bufs, snd_pcm_uframes_t frames);
extern const struct snd_pcm_hw_constraint_list snd_pcm_known_rates;
int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime);
unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate);
static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substream,
struct snd_dma_buffer *bufp)
{
struct snd_pcm_runtime *runtime = substream->runtime;
if (bufp) {
runtime->dma_buffer_p = bufp;
runtime->dma_area = bufp->area;
runtime->dma_addr = bufp->addr;
runtime->dma_bytes = bufp->bytes;
} else {
runtime->dma_buffer_p = NULL;
runtime->dma_area = NULL;
runtime->dma_addr = 0;
runtime->dma_bytes = 0;
}
}
/*
* Timer interface
*/
void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream);
void snd_pcm_timer_init(struct snd_pcm_substream *substream);
void snd_pcm_timer_done(struct snd_pcm_substream *substream);
static inline void snd_pcm_gettime(struct snd_pcm_runtime *runtime,
struct timespec *tv)
{
if (runtime->tstamp_type == SNDRV_PCM_TSTAMP_TYPE_MONOTONIC)
do_posix_clock_monotonic_gettime(tv);
else
getnstimeofday(tv);
}
/*
* Memory
*/
int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream);
int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm);
int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
int type, struct device *data,
size_t size, size_t max);
int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
int type, void *data,
size_t size, size_t max);
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size);
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream);
int _snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream *substream,
size_t size, gfp_t gfp_flags);
int snd_pcm_lib_free_vmalloc_buffer(struct snd_pcm_substream *substream);
struct page *snd_pcm_lib_get_vmalloc_page(struct snd_pcm_substream *substream,
unsigned long offset);
#if 0 /* for kernel-doc */
/**
* snd_pcm_lib_alloc_vmalloc_buffer - allocate virtual DMA buffer
* @substream: the substream to allocate the buffer to
* @size: the requested buffer size, in bytes
*
* Allocates the PCM substream buffer using vmalloc(), i.e., the memory is
* contiguous in kernel virtual space, but not in physical memory. Use this
* if the buffer is accessed by kernel code but not by device DMA.
*
* Returns 1 if the buffer was changed, 0 if not changed, or a negative error
* code.
*/
static int snd_pcm_lib_alloc_vmalloc_buffer
(struct snd_pcm_substream *substream, size_t size);
/**
* snd_pcm_lib_alloc_vmalloc_32_buffer - allocate 32-bit-addressable buffer
* @substream: the substream to allocate the buffer to
* @size: the requested buffer size, in bytes
*
* This function works like snd_pcm_lib_alloc_vmalloc_buffer(), but uses
* vmalloc_32(), i.e., the pages are allocated from 32-bit-addressable memory.
*/
static int snd_pcm_lib_alloc_vmalloc_32_buffer
(struct snd_pcm_substream *substream, size_t size);
#endif
#define snd_pcm_lib_alloc_vmalloc_buffer(subs, size) \
_snd_pcm_lib_alloc_vmalloc_buffer \
(subs, size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO)
#define snd_pcm_lib_alloc_vmalloc_32_buffer(subs, size) \
_snd_pcm_lib_alloc_vmalloc_buffer \
(subs, size, GFP_KERNEL | GFP_DMA32 | __GFP_ZERO)
#ifdef CONFIG_SND_DMA_SGBUF
/*
* SG-buffer handling
*/
#define snd_pcm_substream_sgbuf(substream) \
((substream)->runtime->dma_buffer_p->private_data)
static inline dma_addr_t
snd_pcm_sgbuf_get_addr(struct snd_pcm_substream *substream, unsigned int ofs)
{
struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream);
return snd_sgbuf_get_addr(sg, ofs);
}
static inline void *
snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs)
{
struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream);
return snd_sgbuf_get_ptr(sg, ofs);
}
struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream,
unsigned long offset);
unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
unsigned int ofs, unsigned int size);
#else /* !SND_DMA_SGBUF */
/*
* fake using a continuous buffer
*/
static inline dma_addr_t
snd_pcm_sgbuf_get_addr(struct snd_pcm_substream *substream, unsigned int ofs)
{
return substream->runtime->dma_addr + ofs;
}
static inline void *
snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs)
{
return substream->runtime->dma_area + ofs;
}
#define snd_pcm_sgbuf_ops_page NULL
#define snd_pcm_sgbuf_get_chunk_size(subs, ofs, size) (size)
#endif /* SND_DMA_SGBUF */
/* handle mmap counter - PCM mmap callback should handle this counter properly */
static inline void snd_pcm_mmap_data_open(struct vm_area_struct *area)
{
struct snd_pcm_substream *substream = (struct snd_pcm_substream *)area->vm_private_data;
atomic_inc(&substream->mmap_count);
}
static inline void snd_pcm_mmap_data_close(struct vm_area_struct *area)
{
struct snd_pcm_substream *substream = (struct snd_pcm_substream *)area->vm_private_data;
atomic_dec(&substream->mmap_count);
}
/* mmap for io-memory area */
#if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_ALPHA)
#define SNDRV_PCM_INFO_MMAP_IOMEM SNDRV_PCM_INFO_MMAP
int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream, struct vm_area_struct *area);
#else
#define SNDRV_PCM_INFO_MMAP_IOMEM 0
#define snd_pcm_lib_mmap_iomem NULL
#endif
#define snd_pcm_lib_mmap_vmalloc NULL
static inline void snd_pcm_limit_isa_dma_size(int dma, size_t *max)
{
*max = dma < 4 ? 64 * 1024 : 128 * 1024;
}
/*
* Misc
*/
#define SNDRV_PCM_DEFAULT_CON_SPDIF (IEC958_AES0_CON_EMPHASIS_NONE|\
(IEC958_AES1_CON_ORIGINAL<<8)|\
(IEC958_AES1_CON_PCM_CODER<<8)|\
(IEC958_AES3_CON_FS_48000<<24))
#define PCM_RUNTIME_CHECK(sub) snd_BUG_ON(!(sub) || !(sub)->runtime)
const char *snd_pcm_format_name(snd_pcm_format_t format);
#endif /* __SOUND_PCM_H */
Reference in New Issue View Git Blame Copy Permalink