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 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[]; /* 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
snd_ctl_get_ioffnum(struct snd_kcontrol * kctl,struct snd_ctl_elem_id * id)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
snd_ctl_get_ioffidx(struct snd_kcontrol * kctl,struct snd_ctl_elem_id * id)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
snd_ctl_get_ioff(struct snd_kcontrol * kctl,struct snd_ctl_elem_id * id)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
snd_ctl_build_ioff(struct snd_ctl_elem_id * dst_id,struct snd_kcontrol * src_kctl,unsigned int offset)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_follower(struct snd_kcontrol *master,
192 struct snd_kcontrol *follower,
193 unsigned int flags);
194 /* optional flags for follower */
195 #define SND_CTL_FOLLOWER_NEED_UPDATE (1 << 0)
196
197 /**
198 * snd_ctl_add_follower - Add a virtual follower control
199 * @master: vmaster element
200 * @follower: follower element to add
201 *
202 * Add a virtual follower control to the given master element created via
203 * snd_ctl_create_virtual_master() beforehand.
204 *
205 * All followers must be the same type (returning the same information
206 * via info callback). The function doesn't check it, so it's your
207 * responsibility.
208 *
209 * Also, some additional limitations:
210 * at most two channels,
211 * logarithmic volume control (dB level) thus no linear volume,
212 * master can only attenuate the volume without gain
213 *
214 * Return: Zero if successful or a negative error code.
215 */
216 static inline int
snd_ctl_add_follower(struct snd_kcontrol * master,struct snd_kcontrol * follower)217 snd_ctl_add_follower(struct snd_kcontrol *master, struct snd_kcontrol *follower)
218 {
219 return _snd_ctl_add_follower(master, follower, 0);
220 }
221
222 /**
223 * snd_ctl_add_follower_uncached - Add a virtual follower control
224 * @master: vmaster element
225 * @follower: follower element to add
226 *
227 * Add a virtual follower control to the given master.
228 * Unlike snd_ctl_add_follower(), the element added via this function
229 * is supposed to have volatile values, and get callback is called
230 * at each time queried from the master.
231 *
232 * When the control peeks the hardware values directly and the value
233 * can be changed by other means than the put callback of the element,
234 * this function should be used to keep the value always up-to-date.
235 *
236 * Return: Zero if successful or a negative error code.
237 */
238 static inline int
snd_ctl_add_follower_uncached(struct snd_kcontrol * master,struct snd_kcontrol * follower)239 snd_ctl_add_follower_uncached(struct snd_kcontrol *master,
240 struct snd_kcontrol *follower)
241 {
242 return _snd_ctl_add_follower(master, follower, SND_CTL_FOLLOWER_NEED_UPDATE);
243 }
244
245 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
246 void (*hook)(void *private_data, int),
247 void *private_data);
248 void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
249 #define snd_ctl_sync_vmaster_hook(kctl) snd_ctl_sync_vmaster(kctl, true)
250 int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
251 int (*func)(struct snd_kcontrol *vfollower,
252 struct snd_kcontrol *follower,
253 void *arg),
254 void *arg);
255
256 /*
257 * Helper functions for jack-detection controls
258 */
259 struct snd_kcontrol *
260 snd_kctl_jack_new(const char *name, struct snd_card *card);
261 void snd_kctl_jack_report(struct snd_card *card,
262 struct snd_kcontrol *kctl, bool status);
263
264 #endif /* __SOUND_CONTROL_H */
265
