#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 IS_ENABLED(CONFIG_SND_PCM_OSS)
#include <sound/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_audio_tstamp_config; /* definitions further down */
struct snd_pcm_audio_tstamp_report;

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 (*get_time_info)(struct snd_pcm_substream *substream,
                        struct timespec *system_ts, struct timespec *audio_ts,
                        struct snd_pcm_audio_tstamp_config *audio_tstamp_config,
                        struct snd_pcm_audio_tstamp_report *audio_tstamp_report);
        int (*fill_silence)(struct snd_pcm_substream *substream, int channel,
                            unsigned long pos, unsigned long bytes);
        int (*copy_user)(struct snd_pcm_substream *substream, int channel,
                         unsigned long pos, void __user *buf,
                         unsigned long bytes);
        int (*copy_kernel)(struct snd_pcm_substream *substream, int channel,
                           unsigned long pos, void *buf, unsigned long bytes);
        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_RESET          0
/* 1 is absent slot. */
#define SNDRV_PCM_IOCTL1_CHANNEL_INFO   2
/* 3 is absent slot. */
#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_TRIGGER_DRAIN         7

#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_S20_LE _SNDRV_PCM_FMTBIT(S20_LE)
#define SNDRV_PCM_FMTBIT_U20_LE _SNDRV_PCM_FMTBIT(U20_LE)
#define SNDRV_PCM_FMTBIT_S20_BE _SNDRV_PCM_FMTBIT(S20_BE)
#define SNDRV_PCM_FMTBIT_U20_BE _SNDRV_PCM_FMTBIT(U20_BE)
#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)
#define SNDRV_PCM_FMTBIT_DSD_U8         _SNDRV_PCM_FMTBIT(DSD_U8)
#define SNDRV_PCM_FMTBIT_DSD_U16_LE     _SNDRV_PCM_FMTBIT(DSD_U16_LE)
#define SNDRV_PCM_FMTBIT_DSD_U32_LE     _SNDRV_PCM_FMTBIT(DSD_U32_LE)
#define SNDRV_PCM_FMTBIT_DSD_U16_BE     _SNDRV_PCM_FMTBIT(DSD_U16_BE)
#define SNDRV_PCM_FMTBIT_DSD_U32_BE     _SNDRV_PCM_FMTBIT(DSD_U32_BE)

#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
#define SNDRV_PCM_FMTBIT_S20            SNDRV_PCM_FMTBIT_S20_LE
#define SNDRV_PCM_FMTBIT_U20            SNDRV_PCM_FMTBIT_U20_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
#define SNDRV_PCM_FMTBIT_S20            SNDRV_PCM_FMTBIT_S20_BE
#define SNDRV_PCM_FMTBIT_U20            SNDRV_PCM_FMTBIT_U20_BE
#endif

struct snd_pcm_file {
        struct snd_pcm_substream *substream;
        int no_compat_mmap;
        unsigned int user_pversion;     /* supported protocol version */
};

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;
        int var;
        int deps[4];

        snd_pcm_hw_rule_func_t func;
        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;
        const struct snd_ratnum *rats;
};

struct snd_pcm_hw_constraint_ratdens {
        int nrats;
        const struct snd_ratden *rats;
};

struct snd_pcm_hw_constraint_list {
        const unsigned int *list;
        unsigned int count;
        unsigned int mask;
};

struct snd_pcm_hw_constraint_ranges {
        unsigned int count;
        const struct snd_interval *ranges;
        unsigned int mask;
};

/*
 * userspace-provided audio timestamp config to kernel,
 * structure is for internal use only and filled with dedicated unpack routine
 */
struct snd_pcm_audio_tstamp_config {
        /* 5 of max 16 bits used */
        u32 type_requested:4;
        u32 report_delay:1; /* add total delay to A/D or D/A */
};

static inline void snd_pcm_unpack_audio_tstamp_config(__u32 data,
                                                struct snd_pcm_audio_tstamp_config *config)
{
        config->type_requested = data & 0xF;
        config->report_delay = (data >> 4) & 1;
}

/*
 * kernel-provided audio timestamp report to user-space
 * structure is for internal use only and read by dedicated pack routine
 */
struct snd_pcm_audio_tstamp_report {
        /* 6 of max 16 bits used for bit-fields */

        /* for backwards compatibility */
        u32 valid:1;

        /* actual type if hardware could not support requested timestamp */
        u32 actual_type:4;

        /* accuracy represented in ns units */
        u32 accuracy_report:1; /* 0 if accuracy unknown, 1 if accuracy field is valid */
        u32 accuracy; /* up to 4.29s, will be packed in separate field  */
};

static inline void snd_pcm_pack_audio_tstamp_report(__u32 *data, __u32 *accuracy,
                                                const struct snd_pcm_audio_tstamp_report *report)
{
        u32 tmp;

        tmp = report->accuracy_report;
        tmp <<= 4;
        tmp |= report->actual_type;
        tmp <<= 1;
        tmp |= report->valid;

        *data &= 0xffff; /* zero-clear MSBs */
        *data |= (tmp << 16);
        *accuracy = report->accuracy;
}


struct snd_pcm_runtime {
        /* -- Status -- */
        struct snd_pcm_substream *trigger_master;
        struct timespec trigger_tstamp; /* trigger timestamp */
        bool trigger_tstamp_latched;     /* trigger timestamp latched in low-level driver/hardware */
        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 */
        u64 hw_ptr_wrap;                /* offset for hw_ptr due to boundary wrap-around */

        /* -- 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;

        /* -- 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 */

        /* -- audio timestamp config -- */
        struct snd_pcm_audio_tstamp_config audio_tstamp_config;
        struct snd_pcm_audio_tstamp_report audio_tstamp_report;
        struct timespec driver_tstamp;

#if IS_ENABLED(CONFIG_SND_PCM_OSS)
        /* -- OSS things -- */
        struct snd_pcm_oss_runtime oss;
#endif
};

struct snd_pcm_group {          /* keep linked substreams */
        spinlock_t lock;
        struct mutex mutex;
        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;
        size_t dma_max;
        /* -- hardware operations -- */
        const 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 */
        long wait_time; /* time in ms for R/W to wait for avail */
        /* -- 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 IS_ENABLED(CONFIG_SND_PCM_OSS)
        /* -- 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;
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
        struct snd_info_entry *proc_xrun_injection_entry;
#endif
#endif /* CONFIG_SND_VERBOSE_PROCFS */
        /* 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 IS_ENABLED(CONFIG_SND_PCM_OSS)
        /* -- 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_kcontrol *chmap_kctl; /* channel-mapping controls */
        struct device dev;
};

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);
        bool internal; /* pcm is for internal use only */
        bool nonatomic; /* whole PCM operations are in non-atomic context */
#if IS_ENABLED(CONFIG_SND_PCM_OSS)
        struct snd_pcm_oss oss;
#endif
};

/*
 *  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_internal(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);

#if IS_ENABLED(CONFIG_SND_PCM_OSS)
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;
};
int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree);
#endif

/*
 *  Native I/O
 */

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);
int snd_pcm_stop_xrun(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);
#else
static inline int snd_pcm_suspend(struct snd_pcm_substream *substream)
{
        return 0;
}
static inline int snd_pcm_suspend_all(struct snd_pcm *pcm)
{
        return 0;
}
#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);
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
 */

/**
 * snd_pcm_stream_linked - Check whether the substream is linked with others
 * @substream: substream to check
 *
 * Returns true if the given substream is being linked with others.
 */
static inline int snd_pcm_stream_linked(struct snd_pcm_substream *substream)
{
        return substream->group != &substream->self_group;
}

void snd_pcm_stream_lock(struct snd_pcm_substream *substream);
void snd_pcm_stream_unlock(struct snd_pcm_substream *substream);
void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream);
void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream);
unsigned long _snd_pcm_stream_lock_irqsave(struct snd_pcm_substream *substream);

/**
 * snd_pcm_stream_lock_irqsave - Lock the PCM stream
 * @substream: PCM substream
 * @flags: irq flags
 *
 * This locks the PCM stream like snd_pcm_stream_lock() but with the local
 * IRQ (only when nonatomic is false).  In nonatomic case, this is identical
 * as snd_pcm_stream_lock().
 */
#define snd_pcm_stream_lock_irqsave(substream, flags)            \
        do {                                                     \
                typecheck(unsigned long, flags);                 \
                flags = _snd_pcm_stream_lock_irqsave(substream); \
        } while (0)
void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream,
                                      unsigned long flags);

/**
 * snd_pcm_group_for_each_entry - iterate over the linked substreams
 * @s: the iterator
 * @substream: the substream
 *
 * Iterate over the all linked substreams to the given @substream.
 * When @substream isn't linked with any others, this gives returns @substream
 * itself once.
 */
#define snd_pcm_group_for_each_entry(s, substream) \
        list_for_each_entry(s, &substream->group->substreams, link_list)

/**
 * snd_pcm_running - Check whether the substream is in a running state
 * @substream: substream to check
 *
 * Returns true if the given substream is in the state RUNNING, or in the
 * state DRAINING for playback.
 */
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));
}

/**
 * bytes_to_samples - Unit conversion of the size from bytes to samples
 * @runtime: PCM runtime instance
 * @size: size in bytes
 */
static inline ssize_t bytes_to_samples(struct snd_pcm_runtime *runtime, ssize_t size)
{
        return size * 8 / runtime->sample_bits;
}

/**
 * bytes_to_frames - Unit conversion of the size from bytes to frames
 * @runtime: PCM runtime instance
 * @size: size in bytes
 */
static inline snd_pcm_sframes_t bytes_to_frames(struct snd_pcm_runtime *runtime, ssize_t size)
{
        return size * 8 / runtime->frame_bits;
}

/**
 * samples_to_bytes - Unit conversion of the size from samples to bytes
 * @runtime: PCM runtime instance
 * @size: size in samples
 */
static inline ssize_t samples_to_bytes(struct snd_pcm_runtime *runtime, ssize_t size)
{
        return size * runtime->sample_bits / 8;
}

/**
 * frames_to_bytes - Unit conversion of the size from frames to bytes
 * @runtime: PCM runtime instance
 * @size: size in frames
 */
static inline ssize_t frames_to_bytes(struct snd_pcm_runtime *runtime, snd_pcm_sframes_t size)
{
        return size * runtime->frame_bits / 8;
}

/**
 * frame_aligned - Check whether the byte size is aligned to frames
 * @runtime: PCM runtime instance
 * @bytes: size in bytes
 */
static inline int frame_aligned(struct snd_pcm_runtime *runtime, ssize_t bytes)
{
        return bytes % runtime->byte_align == 0;
}

/**
 * snd_pcm_lib_buffer_bytes - Get the buffer size of the current PCM in bytes
 * @substream: PCM substream
 */
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);
}

/**
 * snd_pcm_lib_period_bytes - Get the period size of the current PCM in bytes
 * @substream: PCM substream
 */
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);
}

/**
 * snd_pcm_playback_avail - Get the available (writable) space for playback
 * @runtime: PCM runtime instance
 *
 * Result is between 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;
}

/**
 * snd_pcm_playback_avail - Get the available (readable) space for capture
 * @runtime: PCM runtime instance
 *
 * Result is between 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;
}

/**
 * snd_pcm_playback_hw_avail - Get the queued space for playback
 * @runtime: PCM runtime instance
 */
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);
}

/**
 * snd_pcm_capture_hw_avail - Get the free space for capture
 * @runtime: PCM runtime instance
 */
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.
 *
 * Return: 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.
 *
 * Return: 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.
 *
 * Return: Non-zero if any data exists, or zero if not. If stop_threshold
 * is bigger or equal to boundary, then this function returns always non-zero.
 */
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.
 *
 * Return: 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.
 *
 * Return: 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;
}

/**
 * snd_pcm_trigger_done - Mark the master substream
 * @substream: the pcm substream instance
 * @master: the linked master substream
 *
 * When multiple substreams of the same card are linked and the hardware
 * supports the single-shot operation, the driver calls this in the loop
 * in snd_pcm_group_for_each_entry() for marking the substream as "done".
 * Then most of trigger operations are performed only to the given master
 * substream.
 *
 * The trigger_master mark is cleared at timestamp updates at the end
 * of trigger operations.
 */
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];
}

/**
 * params_channels - Get the number of channels from the hw params
 * @p: hw params
 */
static inline unsigned int params_channels(const struct snd_pcm_hw_params *p)
{
        return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_CHANNELS)->min;
}

/**
 * params_rate - Get the sample rate from the hw params
 * @p: hw params
 */
static inline unsigned int params_rate(const struct snd_pcm_hw_params *p)
{
        return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_RATE)->min;
}

/**
 * params_period_size - Get the period size (in frames) from the hw params
 * @p: hw params
 */
static inline unsigned int params_period_size(const struct snd_pcm_hw_params *p)
{
        return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_PERIOD_SIZE)->min;
}

/**
 * params_periods - Get the number of periods from the hw params
 * @p: hw params
 */
static inline unsigned int params_periods(const struct snd_pcm_hw_params *p)
{
        return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_PERIODS)->min;
}

/**
 * params_buffer_size - Get the buffer size (in frames) from the hw params
 * @p: hw params
 */
static inline unsigned int params_buffer_size(const struct snd_pcm_hw_params *p)
{
        return hw_param_interval_c(p, SNDRV_PCM_HW_PARAM_BUFFER_SIZE)->min;
}

/**
 * params_buffer_bytes - Get the buffer size (in bytes) from the hw params
 * @p: hw params
 */
static inline unsigned int params_buffer_bytes(const struct snd_pcm_hw_params *p)
{
        return 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);
int snd_interval_list(struct snd_interval *i, unsigned int count,
                      const unsigned int *list, unsigned int mask);
int snd_interval_ranges(struct snd_interval *i, unsigned int count,
                        const struct snd_interval *list, unsigned int mask);
int snd_interval_ratnum(struct snd_interval *i,
                        unsigned int rats_count, const 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_refine(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params);

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,
                               const struct snd_pcm_hw_constraint_list *l);
int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
                                 unsigned int cond,
                                 snd_pcm_hw_param_t var,
                                 const struct snd_pcm_hw_constraint_ranges *r);
int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, 
                                  unsigned int cond,
                                  snd_pcm_hw_param_t var,
                                  const 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,
                                  const 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_noresample(struct snd_pcm_runtime *runtime,
                               unsigned int base_rate);
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, ...);

/**
 * snd_pcm_hw_constraint_single() - Constrain parameter to a single value
 * @runtime: PCM runtime instance
 * @var: The hw_params variable to constrain
 * @val: The value to constrain to
 *
 * Return: Positive if the value is changed, zero if it's not changed, or a
 * negative error code.
 */
static inline int snd_pcm_hw_constraint_single(
        struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
        unsigned int val)
{
        return snd_pcm_hw_constraint_minmax(runtime, var, val, val);
}

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 kernel-doc */
/**
 * snd_pcm_format_cpu_endian - Check the PCM format is CPU-endian
 * @format: the format to check
 *
 * Return: 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);

void snd_pcm_set_ops(struct snd_pcm * pcm, int direction,
                     const struct snd_pcm_ops *ops);
void snd_pcm_set_sync(struct snd_pcm_substream *substream);
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
                      unsigned int cmd, void *arg);                      
void snd_pcm_period_elapsed(struct snd_pcm_substream *substream);
snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
                                     void *buf, bool interleaved,
                                     snd_pcm_uframes_t frames, bool in_kernel);

static inline snd_pcm_sframes_t
snd_pcm_lib_write(struct snd_pcm_substream *substream,
                  const void __user *buf, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, (void __force *)buf, true, frames, false);
}

static inline snd_pcm_sframes_t
snd_pcm_lib_read(struct snd_pcm_substream *substream,
                 void __user *buf, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, (void __force *)buf, true, frames, false);
}

static inline snd_pcm_sframes_t
snd_pcm_lib_writev(struct snd_pcm_substream *substream,
                   void __user **bufs, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, (void *)bufs, false, frames, false);
}

static inline snd_pcm_sframes_t
snd_pcm_lib_readv(struct snd_pcm_substream *substream,
                  void __user **bufs, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, (void *)bufs, false, frames, false);
}

static inline snd_pcm_sframes_t
snd_pcm_kernel_write(struct snd_pcm_substream *substream,
                     const void *buf, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, (void *)buf, true, frames, true);
}

static inline snd_pcm_sframes_t
snd_pcm_kernel_read(struct snd_pcm_substream *substream,
                    void *buf, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, buf, true, frames, true);
}

static inline snd_pcm_sframes_t
snd_pcm_kernel_writev(struct snd_pcm_substream *substream,
                      void **bufs, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, bufs, false, frames, true);
}

static inline snd_pcm_sframes_t
snd_pcm_kernel_readv(struct snd_pcm_substream *substream,
                     void **bufs, snd_pcm_uframes_t frames)
{
        return __snd_pcm_lib_xfer(substream, bufs, false, frames, true);
}

int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime);
unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate);
unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit);
unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
                                         unsigned int rates_b);
unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
                                        unsigned int rate_max);

/**
 * snd_pcm_set_runtime_buffer - Set the PCM runtime buffer
 * @substream: PCM substream to set
 * @bufp: the buffer information, NULL to clear
 *
 * Copy the buffer information to runtime->dma_buffer when @bufp is non-NULL.
 * Otherwise it clears the current buffer information.
 */
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;
        }
}

/**
 * snd_pcm_gettime - Fill the timespec depending on the timestamp mode
 * @runtime: PCM runtime instance
 * @tv: timespec to fill
 */
static inline void snd_pcm_gettime(struct snd_pcm_runtime *runtime,
                                   struct timespec *tv)
{
        switch (runtime->tstamp_type) {
        case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC:
                ktime_get_ts(tv);
                break;
        case SNDRV_PCM_TSTAMP_TYPE_MONOTONIC_RAW:
                getrawmonotonic(tv);
                break;
        default:
                getnstimeofday(tv);
                break;
        }
}

/*
 *  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);
/**
 * 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.
 *
 * Return: 1 if the buffer was changed, 0 if not changed, or a negative error
 * code.
 */
static inline int snd_pcm_lib_alloc_vmalloc_buffer
                        (struct snd_pcm_substream *substream, size_t size)
{
        return _snd_pcm_lib_alloc_vmalloc_buffer(substream, size,
                                                 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
}

/**
 * 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.
 *
 * Return: 1 if the buffer was changed, 0 if not changed, or a negative error
 * code.
 */
static inline int snd_pcm_lib_alloc_vmalloc_32_buffer
                        (struct snd_pcm_substream *substream, size_t size)
{
        return _snd_pcm_lib_alloc_vmalloc_buffer(substream, size,
                                                 GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
}

#define snd_pcm_get_dma_buf(substream) ((substream)->runtime->dma_buffer_p)

#ifdef CONFIG_SND_DMA_SGBUF
/*
 * SG-buffer handling
 */
#define snd_pcm_substream_sgbuf(substream) \
        snd_pcm_get_dma_buf(substream)->private_data

struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream,
                                    unsigned long offset);
#else /* !SND_DMA_SGBUF */
/*
 * fake using a continuous buffer
 */
#define snd_pcm_sgbuf_ops_page  NULL
#endif /* SND_DMA_SGBUF */

/**
 * snd_pcm_sgbuf_get_addr - Get the DMA address at the corresponding offset
 * @substream: PCM substream
 * @ofs: byte offset
 */
static inline dma_addr_t
snd_pcm_sgbuf_get_addr(struct snd_pcm_substream *substream, unsigned int ofs)
{
        return snd_sgbuf_get_addr(snd_pcm_get_dma_buf(substream), ofs);
}

/**
 * snd_pcm_sgbuf_get_ptr - Get the virtual address at the corresponding offset
 * @substream: PCM substream
 * @ofs: byte offset
 */
static inline void *
snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs)
{
        return snd_sgbuf_get_ptr(snd_pcm_get_dma_buf(substream), ofs);
}

/**
 * snd_pcm_sgbuf_chunk_size - Compute the max size that fits within the contig.
 * page from the given size
 * @substream: PCM substream
 * @ofs: byte offset
 * @size: byte size to examine
 */
static inline unsigned int
snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
                             unsigned int ofs, unsigned int size)
{
        return snd_sgbuf_get_chunk_size(snd_pcm_get_dma_buf(substream), ofs, size);
}

/**
 * snd_pcm_mmap_data_open - increase the mmap counter
 * @area: VMA
 *
 * 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);
}

/**
 * snd_pcm_mmap_data_close - decrease the mmap counter
 * @area: VMA
 *
 * PCM mmap callback should handle this counter properly
 */
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);
}

int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
                             struct vm_area_struct *area);
/* 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

/**
 * snd_pcm_limit_isa_dma_size - Get the max size fitting with ISA DMA transfer
 * @dma: DMA number
 * @max: pointer to store the max size
 */
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);

/**
 * snd_pcm_stream_str - Get a string naming the direction of a stream
 * @substream: the pcm substream instance
 *
 * Return: A string naming the direction of the stream.
 */
static inline const char *snd_pcm_stream_str(struct snd_pcm_substream *substream)
{
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                return "Playback";
        else
                return "Capture";
}

/*
 * PCM channel-mapping control API
 */
/* array element of channel maps */
struct snd_pcm_chmap_elem {
        unsigned char channels;
        unsigned char map[15];
};

/* channel map information; retrieved via snd_kcontrol_chip() */
struct snd_pcm_chmap {
        struct snd_pcm *pcm;    /* assigned PCM instance */
        int stream;             /* PLAYBACK or CAPTURE */
        struct snd_kcontrol *kctl;
        const struct snd_pcm_chmap_elem *chmap;
        unsigned int max_channels;
        unsigned int channel_mask;      /* optional: active channels bitmask */
        void *private_data;     /* optional: private data pointer */
};

/**
 * snd_pcm_chmap_substream - get the PCM substream assigned to the given chmap info
 * @info: chmap information
 * @idx: the substream number index
 */
static inline struct snd_pcm_substream *
snd_pcm_chmap_substream(struct snd_pcm_chmap *info, unsigned int idx)
{
        struct snd_pcm_substream *s;
        for (s = info->pcm->streams[info->stream].substream; s; s = s->next)
                if (s->number == idx)
                        return s;
        return NULL;
}

/* ALSA-standard channel maps (RL/RR prior to C/LFE) */
extern const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[];
/* Other world's standard channel maps (C/LFE prior to RL/RR) */
extern const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[];

/* bit masks to be passed to snd_pcm_chmap.channel_mask field */
#define SND_PCM_CHMAP_MASK_24   ((1U << 2) | (1U << 4))
#define SND_PCM_CHMAP_MASK_246  (SND_PCM_CHMAP_MASK_24 | (1U << 6))
#define SND_PCM_CHMAP_MASK_2468 (SND_PCM_CHMAP_MASK_246 | (1U << 8))

int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
                           const struct snd_pcm_chmap_elem *chmap,
                           int max_channels,
                           unsigned long private_value,
                           struct snd_pcm_chmap **info_ret);

/**
 * pcm_format_to_bits - Strong-typed conversion of pcm_format to bitwise
 * @pcm_format: PCM format
 */
static inline u64 pcm_format_to_bits(snd_pcm_format_t pcm_format)
{
        return 1ULL << (__force int) pcm_format;
}

/* printk helpers */
#define pcm_err(pcm, fmt, args...) \
        dev_err((pcm)->card->dev, fmt, ##args)
#define pcm_warn(pcm, fmt, args...) \
        dev_warn((pcm)->card->dev, fmt, ##args)
#define pcm_dbg(pcm, fmt, args...) \
        dev_dbg((pcm)->card->dev, fmt, ##args)

#endif /* __SOUND_PCM_H */