include/sound/control.h

   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
  16 struct snd_kcontrol;
  17 typedef int (snd_kcontrol_info_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo);
  18 typedef int (snd_kcontrol_get_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
  19 typedef int (snd_kcontrol_put_t) (struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol);
  20 typedef 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
  25 enum {
  26         SNDRV_CTL_TLV_OP_READ = 0,
  27         SNDRV_CTL_TLV_OP_WRITE = 1,
  28         SNDRV_CTL_TLV_OP_CMD = -1,
  29 };
  30
  31 struct 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
  49 struct snd_kcontrol_volatile {
  50         struct snd_ctl_file *owner;     /* locked */
  51         unsigned int access;    /* access rights */
  52 };
  53
  54 struct 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
  73 struct 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
  81 struct pid;
  82
  83 enum {
  84         SND_CTL_SUBDEV_PCM,
  85         SND_CTL_SUBDEV_RAWMIDI,
  86         SND_CTL_SUBDEV_ITEMS,
  87 };
  88
  89 struct 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
 103 typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
 104                                       struct snd_ctl_file * control,
 105                                       unsigned int cmd, unsigned long arg);
 106
 107 void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
 108
 109 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
 110 void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
 111 int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
 112 int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
 113 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
 114 int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 115 int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
 116 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 117                         int active);
 118 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
 119 struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 120
 121 int snd_ctl_create(struct snd_card *card);
 122
 123 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
 124 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
 125 #ifdef CONFIG_COMPAT
 126 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 127 int 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
 133 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
 134
 135 static 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
 141 static 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
 147 static 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
 156 static 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  */
 169 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
 170                               struct snd_ctl_elem_info *uinfo);
 171 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
 172                                 struct snd_ctl_elem_info *uinfo);
 173 int 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  */
 179 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 180                                                  const unsigned int *tlv);
 181 int _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  */
 205 static inline int
 206 snd_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  */
 227 static inline int
 228 snd_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
 234 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
 235                              void (*hook)(void *private_data, int),
 236                              void *private_data);
 237 void 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)
 239 int 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  */
 248 struct snd_kcontrol *
 249 snd_kctl_jack_new(const char *name, struct snd_card *card);
 250 void snd_kctl_jack_report(struct snd_card *card,
 251                           struct snd_kcontrol *kctl, bool status);
 252
 253 #endif  /* __SOUND_CONTROL_H */