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
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
41enum {
42 SNDRV_CTL_TLV_OP_READ = 0,
43 SNDRV_CTL_TLV_OP_WRITE = 1,
44 SNDRV_CTL_TLV_OP_CMD = -1,
45};
46
47struct 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
65struct snd_kcontrol_volatile {
66 struct snd_ctl_file *owner; /* locked */
67 unsigned int access; /* access rights */
68};
69
70struct 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
89struct 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
97struct pid;
98
99enum {
100 SND_CTL_SUBDEV_PCM,
101 SND_CTL_SUBDEV_RAWMIDI,
102 SND_CTL_SUBDEV_ITEMS,
103};
104
105struct 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
117struct 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
127typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
128 struct snd_ctl_file * control,
129 unsigned int cmd, unsigned long arg);
130
131void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
132void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kcontrol * kctl, unsigned int ioff);
133
134struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
135void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
136int snd_ctl_add(struct snd_card * card, struct snd_kcontrol * kcontrol);
137int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
138int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
139int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
140int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
141void snd_ctl_rename(struct snd_card *card, struct snd_kcontrol *kctl, const char *name);
142int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active);
143struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid);
144struct 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 */
158static inline struct snd_kcontrol *
159snd_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: &id);
166}
167
168int snd_ctl_create(struct snd_card *card);
169
170int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
171int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
172#ifdef CONFIG_COMPAT
173int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
174int 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
180int snd_ctl_request_layer(const char *module_name);
181void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
182void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);
183
184int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
185
186static 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
192static 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
198static 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
207static 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 */
220int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
221 struct snd_ctl_elem_info *uinfo);
222int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
223 struct snd_ctl_elem_info *uinfo);
224int 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 */
230struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
231 const unsigned int *tlv);
232int _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 */
257static inline int
258snd_ctl_add_follower(struct snd_kcontrol *master, struct snd_kcontrol *follower)
259{
260 return _snd_ctl_add_follower(master, follower, flags: 0);
261}
262
263int 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 */
282static inline int
283snd_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
289int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
290 void (*hook)(void *private_data, int),
291 void *private_data);
292void 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)
294int 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)
306static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
307#else
308static inline int snd_ctl_led_request(void) { return 0; }
309#endif
310
311/*
312 * Helper functions for jack-detection controls
313 */
314struct snd_kcontrol *
315snd_kctl_jack_new(const char *name, struct snd_card *card);
316void snd_kctl_jack_report(struct snd_card *card,
317 struct snd_kcontrol *kctl, bool status);
318
319#endif /* __SOUND_CONTROL_H */
320

source code of linux/include/sound/control.h