linux/include/sound/control.h
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   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2#ifndef __SOUND_CONTROL_H
   3#define __SOUND_CONTROL_H
   4
   5/*
   6 *  Header file for control interface
   7 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   8 */
   9
  10#include <linux/wait.h>
  11#include <linux/nospec.h>
  12#include <sound/asound.h>
  13
  14#define snd_kcontrol_chip(kcontrol) ((kcontrol)->private_data)
  15
  16struct snd_kcontrol;
  17typedef int (snd_kcontrol_info_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo);
  18typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
  19typedef int (snd_kcontrol_put_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
  20typedef int (snd_kcontrol_tlv_rw_t)(struct snd_kcontrol *kcontrol,
  21                                    int op_flag, /* SNDRV_CTL_TLV_OP_XXX */
  22                                    unsigned int size,
  23                                    unsigned int __user *tlv);
  24
  25enum {
  26        SNDRV_CTL_TLV_OP_READ = 0,
  27        SNDRV_CTL_TLV_OP_WRITE = 1,
  28        SNDRV_CTL_TLV_OP_CMD = -1,
  29};
  30
  31struct snd_kcontrol_new {
  32        snd_ctl_elem_iface_t iface;     /* interface identifier */
  33        unsigned int device;            /* device/client number */
  34        unsigned int subdevice;         /* subdevice (substream) number */
  35        const unsigned char *name;      /* ASCII name of item */
  36        unsigned int index;             /* index of item */
  37        unsigned int access;            /* access rights */
  38        unsigned int count;             /* count of same elements */
  39        snd_kcontrol_info_t *info;
  40        snd_kcontrol_get_t *get;
  41        snd_kcontrol_put_t *put;
  42        union {
  43                snd_kcontrol_tlv_rw_t *c;
  44                const unsigned int *p;
  45        } tlv;
  46        unsigned long private_value;
  47};
  48
  49struct snd_kcontrol_volatile {
  50        struct snd_ctl_file *owner;     /* locked */
  51        unsigned int access;    /* access rights */
  52};
  53
  54struct snd_kcontrol {
  55        struct list_head list;          /* list of controls */
  56        struct snd_ctl_elem_id id;
  57        unsigned int count;             /* count of same elements */
  58        snd_kcontrol_info_t *info;
  59        snd_kcontrol_get_t *get;
  60        snd_kcontrol_put_t *put;
  61        union {
  62                snd_kcontrol_tlv_rw_t *c;
  63                const unsigned int *p;
  64        } tlv;
  65        unsigned long private_value;
  66        void *private_data;
  67        void (*private_free)(struct snd_kcontrol *kcontrol);
  68        struct snd_kcontrol_volatile vd[0];     /* volatile data */
  69};
  70
  71#define snd_kcontrol(n) list_entry(n, struct snd_kcontrol, list)
  72
  73struct snd_kctl_event {
  74        struct list_head list;  /* list of events */
  75        struct snd_ctl_elem_id id;
  76        unsigned int mask;
  77};
  78
  79#define snd_kctl_event(n) list_entry(n, struct snd_kctl_event, list)
  80
  81struct pid;
  82
  83enum {
  84        SND_CTL_SUBDEV_PCM,
  85        SND_CTL_SUBDEV_RAWMIDI,
  86        SND_CTL_SUBDEV_ITEMS,
  87};
  88
  89struct snd_ctl_file {
  90        struct list_head list;          /* list of all control files */
  91        struct snd_card *card;
  92        struct pid *pid;
  93        int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
  94        wait_queue_head_t change_sleep;
  95        spinlock_t read_lock;
  96        struct fasync_struct *fasync;
  97        int subscribed;                 /* read interface is activated */
  98        struct list_head events;        /* waiting events for read */
  99};
 100
 101#define snd_ctl_file(n) list_entry(n, struct snd_ctl_file, list)
 102
 103typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
 104                                      struct snd_ctl_file * control,
 105                                      unsigned int cmd, unsigned long arg);
 106
 107void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
 108
 109struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
 110void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
 111int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
 112int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
 113int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
 114int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 115int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
 116int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 117                        int active);
 118struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
 119struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 120
 121int snd_ctl_create(struct snd_card *card);
 122
 123int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
 124int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
 125#ifdef CONFIG_COMPAT
 126int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 127int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 128#else
 129#define snd_ctl_register_ioctl_compat(fcn)
 130#define snd_ctl_unregister_ioctl_compat(fcn)
 131#endif
 132
 133int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
 134
 135static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 136{
 137        unsigned int ioff = id->numid - kctl->id.numid;
 138        return array_index_nospec(ioff, kctl->count);
 139}
 140
 141static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 142{
 143        unsigned int ioff = id->index - kctl->id.index;
 144        return array_index_nospec(ioff, kctl->count);
 145}
 146
 147static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 148{
 149        if (id->numid) {
 150                return snd_ctl_get_ioffnum(kctl, id);
 151        } else {
 152                return snd_ctl_get_ioffidx(kctl, id);
 153        }
 154}
 155
 156static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id *dst_id,
 157                                                    struct snd_kcontrol *src_kctl,
 158                                                    unsigned int offset)
 159{
 160        *dst_id = src_kctl->id;
 161        dst_id->index += offset;
 162        dst_id->numid += offset;
 163        return dst_id;
 164}
 165
 166/*
 167 * Frequently used control callbacks/helpers
 168 */
 169int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
 170                              struct snd_ctl_elem_info *uinfo);
 171int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
 172                                struct snd_ctl_elem_info *uinfo);
 173int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
 174                      unsigned int items, const char *const names[]);
 175
 176/*
 177 * virtual master control
 178 */
 179struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 180                                                 const unsigned int *tlv);
 181int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
 182                       unsigned int flags);
 183/* optional flags for slave */
 184#define SND_CTL_SLAVE_NEED_UPDATE       (1 << 0)
 185
 186/**
 187 * snd_ctl_add_slave - Add a virtual slave control
 188 * @master: vmaster element
 189 * @slave: slave element to add
 190 *
 191 * Add a virtual slave control to the given master element created via
 192 * snd_ctl_create_virtual_master() beforehand.
 193 *
 194 * All slaves must be the same type (returning the same information
 195 * via info callback).  The function doesn't check it, so it's your
 196 * responsibility.
 197 *
 198 * Also, some additional limitations:
 199 * at most two channels,
 200 * logarithmic volume control (dB level) thus no linear volume,
 201 * master can only attenuate the volume without gain
 202 *
 203 * Return: Zero if successful or a negative error code.
 204 */
 205static inline int
 206snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
 207{
 208        return _snd_ctl_add_slave(master, slave, 0);
 209}
 210
 211/**
 212 * snd_ctl_add_slave_uncached - Add a virtual slave control
 213 * @master: vmaster element
 214 * @slave: slave element to add
 215 *
 216 * Add a virtual slave control to the given master.
 217 * Unlike snd_ctl_add_slave(), the element added via this function
 218 * is supposed to have volatile values, and get callback is called
 219 * at each time queried from the master.
 220 *
 221 * When the control peeks the hardware values directly and the value
 222 * can be changed by other means than the put callback of the element,
 223 * this function should be used to keep the value always up-to-date.
 224 *
 225 * Return: Zero if successful or a negative error code.
 226 */
 227static inline int
 228snd_ctl_add_slave_uncached(struct snd_kcontrol *master,
 229                           struct snd_kcontrol *slave)
 230{
 231        return _snd_ctl_add_slave(master, slave, SND_CTL_SLAVE_NEED_UPDATE);
 232}
 233
 234int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
 235                             void (*hook)(void *private_data, int),
 236                             void *private_data);
 237void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
 238#define snd_ctl_sync_vmaster_hook(kctl) snd_ctl_sync_vmaster(kctl, true)
 239int snd_ctl_apply_vmaster_slaves(struct snd_kcontrol *kctl,
 240                                 int (*func)(struct snd_kcontrol *vslave,
 241                                             struct snd_kcontrol *slave,
 242                                             void *arg),
 243                                 void *arg);
 244
 245/*
 246 * Helper functions for jack-detection controls
 247 */
 248struct snd_kcontrol *
 249snd_kctl_jack_new(const char *name, struct snd_card *card);
 250void snd_kctl_jack_report(struct snd_card *card,
 251                          struct snd_kcontrol *kctl, bool status);
 252
 253#endif  /* __SOUND_CONTROL_H */
 254