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 /* internal flag for skipping validations */
  26 #ifdef CONFIG_SND_CTL_DEBUG
  27 #define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK        (1 << 24)
  28 #define snd_ctl_skip_validation(info) \
  29         ((info)->access & SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK)
  30 #else
  31 #define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK        0
  32 #define snd_ctl_skip_validation(info)           true
  33 #endif
  34
  35 /* kernel only - LED bits */
  36 #define SNDRV_CTL_ELEM_ACCESS_LED_SHIFT         25
  37 #define SNDRV_CTL_ELEM_ACCESS_LED_MASK          (7<<25) /* kernel three bits - LED group */
  38 #define SNDRV_CTL_ELEM_ACCESS_SPK_LED           (1<<25) /* kernel speaker (output) LED flag */
  39 #define SNDRV_CTL_ELEM_ACCESS_MIC_LED           (2<<25) /* kernel microphone (input) LED flag */
  40
  41 enum {
  42         SNDRV_CTL_TLV_OP_READ = 0,
  43         SNDRV_CTL_TLV_OP_WRITE = 1,
  44         SNDRV_CTL_TLV_OP_CMD = -1,
  45 };
  46
  47 struct snd_kcontrol_new {
  48         snd_ctl_elem_iface_t iface;     /* interface identifier */
  49         unsigned int device;            /* device/client number */
  50         unsigned int subdevice;         /* subdevice (substream) number */
  51         const char *name;               /* ASCII name of item */
  52         unsigned int index;             /* index of item */
  53         unsigned int access;            /* access rights */
  54         unsigned int count;             /* count of same elements */
  55         snd_kcontrol_info_t *info;
  56         snd_kcontrol_get_t *get;
  57         snd_kcontrol_put_t *put;
  58         union {
  59                 snd_kcontrol_tlv_rw_t *c;
  60                 const unsigned int *p;
  61         } tlv;
  62         unsigned long private_value;
  63 };
  64
  65 struct snd_kcontrol_volatile {
  66         struct snd_ctl_file *owner;     /* locked */
  67         unsigned int access;    /* access rights */
  68 };
  69
  70 struct snd_kcontrol {
  71         struct list_head list;          /* list of controls */
  72         struct snd_ctl_elem_id id;
  73         unsigned int count;             /* count of same elements */
  74         snd_kcontrol_info_t *info;
  75         snd_kcontrol_get_t *get;
  76         snd_kcontrol_put_t *put;
  77         union {
  78                 snd_kcontrol_tlv_rw_t *c;
  79                 const unsigned int *p;
  80         } tlv;
  81         unsigned long private_value;
  82         void *private_data;
  83         void (*private_free)(struct snd_kcontrol *kcontrol);
  84         struct snd_kcontrol_volatile vd[] __counted_by(count);  /* volatile data */
  85 };
  86
  87 #define snd_kcontrol(n) list_entry(n, struct snd_kcontrol, list)
  88
  89 struct snd_kctl_event {
  90         struct list_head list;  /* list of events */
  91         struct snd_ctl_elem_id id;
  92         unsigned int mask;
  93 };
  94
  95 #define snd_kctl_event(n) list_entry(n, struct snd_kctl_event, list)
  96
  97 struct pid;
  98
  99 enum {
 100         SND_CTL_SUBDEV_PCM,
 101         SND_CTL_SUBDEV_RAWMIDI,
 102         SND_CTL_SUBDEV_ITEMS,
 103 };
 104
 105 struct snd_ctl_file {
 106         struct list_head list;          /* list of all control files */
 107         struct snd_card *card;
 108         struct pid *pid;
 109         int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
 110         wait_queue_head_t change_sleep;
 111         spinlock_t read_lock;
 112         struct snd_fasync *fasync;
 113         int subscribed;                 /* read interface is activated */
 114         struct list_head events;        /* waiting events for read */
 115 };
 116
 117 struct snd_ctl_layer_ops {
 118         struct snd_ctl_layer_ops *next;
 119         const char *module_name;
 120         void (*lregister)(struct snd_card *card);
 121         void (*ldisconnect)(struct snd_card *card);
 122         void (*lnotify)(struct snd_card *card, unsigned int mask, struct snd_kcontrol *kctl, unsigned int ioff);
 123 };
 124
 125 #define snd_ctl_file(n) list_entry(n, struct snd_ctl_file, list)
 126
 127 typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
 128                                       struct snd_ctl_file * control,
 129                                       unsigned int cmd, unsigned long arg);
 130
 131 void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
 132 void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kcontrol * kctl, unsigned int ioff);
 133
 134 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
 135 void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
 136 int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
 137 int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
 138 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
 139 int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 140 int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
 141 void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl, const char *name);
 142 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active);
 143 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid);
 144 struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card, const struct snd_ctl_elem_id *id);
 145
 146 /**
 147  * snd_ctl_find_id_mixer - find the control instance with the given name string
 148  * @card: the card instance
 149  * @name: the name string
 150  *
 151  * Finds the control instance with the given name and
 152  * @SNDRV_CTL_ELEM_IFACE_MIXER. Other fields are set to zero.
 153  *
 154  * This is merely a wrapper to snd_ctl_find_id().
 155  *
 156  * Return: The pointer of the instance if found, or %NULL if not.
 157  */
 158 static inline struct snd_kcontrol *
 159 snd_ctl_find_id_mixer(struct snd_card *card, const char *name)
 160 {
 161         struct snd_ctl_elem_id id = {};
 162
 163         id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 164         strscpy(id.name, name, sizeof(id.name));
 165         return snd_ctl_find_id(card, &id);
 166 }
 167
 168 int snd_ctl_create(struct snd_card *card);
 169
 170 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
 171 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
 172 #ifdef CONFIG_COMPAT
 173 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 174 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 175 #else
 176 #define snd_ctl_register_ioctl_compat(fcn)
 177 #define snd_ctl_unregister_ioctl_compat(fcn)
 178 #endif
 179
 180 int snd_ctl_request_layer(const char *module_name);
 181 void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
 182 void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);
 183
 184 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
 185
 186 static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 187 {
 188         unsigned int ioff = id->numid - kctl->id.numid;
 189         return array_index_nospec(ioff, kctl->count);
 190 }
 191
 192 static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 193 {
 194         unsigned int ioff = id->index - kctl->id.index;
 195         return array_index_nospec(ioff, kctl->count);
 196 }
 197
 198 static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 199 {
 200         if (id->numid) {
 201                 return snd_ctl_get_ioffnum(kctl, id);
 202         } else {
 203                 return snd_ctl_get_ioffidx(kctl, id);
 204         }
 205 }
 206
 207 static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id *dst_id,
 208                                                     struct snd_kcontrol *src_kctl,
 209                                                     unsigned int offset)
 210 {
 211         *dst_id = src_kctl->id;
 212         dst_id->index += offset;
 213         dst_id->numid += offset;
 214         return dst_id;
 215 }
 216
 217 /*
 218  * Frequently used control callbacks/helpers
 219  */
 220 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
 221                               struct snd_ctl_elem_info *uinfo);
 222 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
 223                                 struct snd_ctl_elem_info *uinfo);
 224 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
 225                       unsigned int items, const char *const names[]);
 226
 227 /*
 228  * virtual master control
 229  */
 230 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 231                                                  const unsigned int *tlv);
 232 int _snd_ctl_add_follower(struct snd_kcontrol *master,
 233                           struct snd_kcontrol *follower,
 234                           unsigned int flags);
 235 /* optional flags for follower */
 236 #define SND_CTL_FOLLOWER_NEED_UPDATE    (1 << 0)
 237
 238 /**
 239  * snd_ctl_add_follower - Add a virtual follower control
 240  * @master: vmaster element
 241  * @follower: follower element to add
 242  *
 243  * Add a virtual follower control to the given master element created via
 244  * snd_ctl_create_virtual_master() beforehand.
 245  *
 246  * All followers must be the same type (returning the same information
 247  * via info callback).  The function doesn't check it, so it's your
 248  * responsibility.
 249  *
 250  * Also, some additional limitations:
 251  * at most two channels,
 252  * logarithmic volume control (dB level) thus no linear volume,
 253  * master can only attenuate the volume without gain
 254  *
 255  * Return: Zero if successful or a negative error code.
 256  */
 257 static inline int
 258 snd_ctl_add_follower(struct snd_kcontrol *master, struct snd_kcontrol *follower)
 259 {
 260         return _snd_ctl_add_follower(master, follower, 0);
 261 }
 262
 263 int snd_ctl_add_followers(struct snd_card *card, struct snd_kcontrol *master,
 264                           const char * const *list);
 265
 266 /**
 267  * snd_ctl_add_follower_uncached - Add a virtual follower control
 268  * @master: vmaster element
 269  * @follower: follower element to add
 270  *
 271  * Add a virtual follower control to the given master.
 272  * Unlike snd_ctl_add_follower(), the element added via this function
 273  * is supposed to have volatile values, and get callback is called
 274  * at each time queried from the master.
 275  *
 276  * When the control peeks the hardware values directly and the value
 277  * can be changed by other means than the put callback of the element,
 278  * this function should be used to keep the value always up-to-date.
 279  *
 280  * Return: Zero if successful or a negative error code.
 281  */
 282 static inline int
 283 snd_ctl_add_follower_uncached(struct snd_kcontrol *master,
 284                               struct snd_kcontrol *follower)
 285 {
 286         return _snd_ctl_add_follower(master, follower, SND_CTL_FOLLOWER_NEED_UPDATE);
 287 }
 288
 289 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
 290                              void (*hook)(void *private_data, int),
 291                              void *private_data);
 292 void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
 293 #define snd_ctl_sync_vmaster_hook(kctl) snd_ctl_sync_vmaster(kctl, true)
 294 int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
 295                                     int (*func)(struct snd_kcontrol *vfollower,
 296                                                 struct snd_kcontrol *follower,
 297                                                 void *arg),
 298                                     void *arg);
 299
 300 /*
 301  * Control LED trigger layer
 302  */
 303 #define SND_CTL_LAYER_MODULE_LED        "snd-ctl-led"
 304
 305 #if IS_MODULE(CONFIG_SND_CTL_LED)
 306 static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
 307 #else
 308 static inline int snd_ctl_led_request(void) { return 0; }
 309 #endif
 310
 311 /*
 312  * Helper functions for jack-detection controls
 313  */
 314 struct snd_kcontrol *
 315 snd_kctl_jack_new(const char *name, struct snd_card *card);
 316 void snd_kctl_jack_report(struct snd_card *card,
 317                           struct snd_kcontrol *kctl, bool status);
 318
 319 #endif  /* __SOUND_CONTROL_H */