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_VALIDATION
  27 #define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK        (1 << 27)
  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 enum {
  36         SNDRV_CTL_TLV_OP_READ = 0,
  37         SNDRV_CTL_TLV_OP_WRITE = 1,
  38         SNDRV_CTL_TLV_OP_CMD = -1,
  39 };
  40
  41 struct snd_kcontrol_new {
  42         snd_ctl_elem_iface_t iface;     /* interface identifier */
  43         unsigned int device;            /* device/client number */
  44         unsigned int subdevice;         /* subdevice (substream) number */
  45         const unsigned char *name;      /* ASCII name of item */
  46         unsigned int index;             /* index of item */
  47         unsigned int access;            /* access rights */
  48         unsigned int count;             /* count of same elements */
  49         snd_kcontrol_info_t *info;
  50         snd_kcontrol_get_t *get;
  51         snd_kcontrol_put_t *put;
  52         union {
  53                 snd_kcontrol_tlv_rw_t *c;
  54                 const unsigned int *p;
  55         } tlv;
  56         unsigned long private_value;
  57 };
  58
  59 struct snd_kcontrol_volatile {
  60         struct snd_ctl_file *owner;     /* locked */
  61         unsigned int access;    /* access rights */
  62 };
  63
  64 struct snd_kcontrol {
  65         struct list_head list;          /* list of controls */
  66         struct snd_ctl_elem_id id;
  67         unsigned int count;             /* count of same elements */
  68         snd_kcontrol_info_t *info;
  69         snd_kcontrol_get_t *get;
  70         snd_kcontrol_put_t *put;
  71         union {
  72                 snd_kcontrol_tlv_rw_t *c;
  73                 const unsigned int *p;
  74         } tlv;
  75         unsigned long private_value;
  76         void *private_data;
  77         void (*private_free)(struct snd_kcontrol *kcontrol);
  78         struct snd_kcontrol_volatile vd[0];     /* volatile data */
  79 };
  80
  81 #define snd_kcontrol(n) list_entry(n, struct snd_kcontrol, list)
  82
  83 struct snd_kctl_event {
  84         struct list_head list;  /* list of events */
  85         struct snd_ctl_elem_id id;
  86         unsigned int mask;
  87 };
  88
  89 #define snd_kctl_event(n) list_entry(n, struct snd_kctl_event, list)
  90
  91 struct pid;
  92
  93 enum {
  94         SND_CTL_SUBDEV_PCM,
  95         SND_CTL_SUBDEV_RAWMIDI,
  96         SND_CTL_SUBDEV_ITEMS,
  97 };
  98
  99 struct snd_ctl_file {
 100         struct list_head list;          /* list of all control files */
 101         struct snd_card *card;
 102         struct pid *pid;
 103         int preferred_subdevice[SND_CTL_SUBDEV_ITEMS];
 104         wait_queue_head_t change_sleep;
 105         spinlock_t read_lock;
 106         struct fasync_struct *fasync;
 107         int subscribed;                 /* read interface is activated */
 108         struct list_head events;        /* waiting events for read */
 109 };
 110
 111 #define snd_ctl_file(n) list_entry(n, struct snd_ctl_file, list)
 112
 113 typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
 114                                       struct snd_ctl_file * control,
 115                                       unsigned int cmd, unsigned long arg);
 116
 117 void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
 118
 119 struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
 120 void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
 121 int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
 122 int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
 123 int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
 124 int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 125 int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
 126 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
 127                         int active);
 128 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
 129 struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);
 130
 131 int snd_ctl_create(struct snd_card *card);
 132
 133 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
 134 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
 135 #ifdef CONFIG_COMPAT
 136 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 137 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
 138 #else
 139 #define snd_ctl_register_ioctl_compat(fcn)
 140 #define snd_ctl_unregister_ioctl_compat(fcn)
 141 #endif
 142
 143 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
 144
 145 static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 146 {
 147         unsigned int ioff = id->numid - kctl->id.numid;
 148         return array_index_nospec(ioff, kctl->count);
 149 }
 150
 151 static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 152 {
 153         unsigned int ioff = id->index - kctl->id.index;
 154         return array_index_nospec(ioff, kctl->count);
 155 }
 156
 157 static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
 158 {
 159         if (id->numid) {
 160                 return snd_ctl_get_ioffnum(kctl, id);
 161         } else {
 162                 return snd_ctl_get_ioffidx(kctl, id);
 163         }
 164 }
 165
 166 static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id *dst_id,
 167                                                     struct snd_kcontrol *src_kctl,
 168                                                     unsigned int offset)
 169 {
 170         *dst_id = src_kctl->id;
 171         dst_id->index += offset;
 172         dst_id->numid += offset;
 173         return dst_id;
 174 }
 175
 176 /*
 177  * Frequently used control callbacks/helpers
 178  */
 179 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
 180                               struct snd_ctl_elem_info *uinfo);
 181 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
 182                                 struct snd_ctl_elem_info *uinfo);
 183 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
 184                       unsigned int items, const char *const names[]);
 185
 186 /*
 187  * virtual master control
 188  */
 189 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 190                                                  const unsigned int *tlv);
 191 int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
 192                        unsigned int flags);
 193 /* optional flags for slave */
 194 #define SND_CTL_SLAVE_NEED_UPDATE       (1 << 0)
 195
 196 /**
 197  * snd_ctl_add_slave - Add a virtual slave control
 198  * @master: vmaster element
 199  * @slave: slave element to add
 200  *
 201  * Add a virtual slave control to the given master element created via
 202  * snd_ctl_create_virtual_master() beforehand.
 203  *
 204  * All slaves must be the same type (returning the same information
 205  * via info callback).  The function doesn't check it, so it's your
 206  * responsibility.
 207  *
 208  * Also, some additional limitations:
 209  * at most two channels,
 210  * logarithmic volume control (dB level) thus no linear volume,
 211  * master can only attenuate the volume without gain
 212  *
 213  * Return: Zero if successful or a negative error code.
 214  */
 215 static inline int
 216 snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave)
 217 {
 218         return _snd_ctl_add_slave(master, slave, 0);
 219 }
 220
 221 /**
 222  * snd_ctl_add_slave_uncached - Add a virtual slave control
 223  * @master: vmaster element
 224  * @slave: slave element to add
 225  *
 226  * Add a virtual slave control to the given master.
 227  * Unlike snd_ctl_add_slave(), the element added via this function
 228  * is supposed to have volatile values, and get callback is called
 229  * at each time queried from the master.
 230  *
 231  * When the control peeks the hardware values directly and the value
 232  * can be changed by other means than the put callback of the element,
 233  * this function should be used to keep the value always up-to-date.
 234  *
 235  * Return: Zero if successful or a negative error code.
 236  */
 237 static inline int
 238 snd_ctl_add_slave_uncached(struct snd_kcontrol *master,
 239                            struct snd_kcontrol *slave)
 240 {
 241         return _snd_ctl_add_slave(master, slave, SND_CTL_SLAVE_NEED_UPDATE);
 242 }
 243
 244 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
 245                              void (*hook)(void *private_data, int),
 246                              void *private_data);
 247 void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
 248 #define snd_ctl_sync_vmaster_hook(kctl) snd_ctl_sync_vmaster(kctl, true)
 249 int snd_ctl_apply_vmaster_slaves(struct snd_kcontrol *kctl,
 250                                  int (*func)(struct snd_kcontrol *vslave,
 251                                              struct snd_kcontrol *slave,
 252                                              void *arg),
 253                                  void *arg);
 254
 255 /*
 256  * Helper functions for jack-detection controls
 257  */
 258 struct snd_kcontrol *
 259 snd_kctl_jack_new(const char *name, struct snd_card *card);
 260 void snd_kctl_jack_report(struct snd_card *card,
 261                           struct snd_kcontrol *kctl, bool status);
 262
 263 #endif  /* __SOUND_CONTROL_H */