xref: /linux/include/sound/control.h (revision 288440de9e5fdb4a3ff73864850f080c1250fc81)
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[];	/* 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 int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active);
142 struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
143 struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);
144 
145 int snd_ctl_create(struct snd_card *card);
146 
147 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
148 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
149 #ifdef CONFIG_COMPAT
150 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
151 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
152 #else
153 #define snd_ctl_register_ioctl_compat(fcn)
154 #define snd_ctl_unregister_ioctl_compat(fcn)
155 #endif
156 
157 int snd_ctl_request_layer(const char *module_name);
158 void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
159 void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);
160 
161 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
162 
163 static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
164 {
165 	unsigned int ioff = id->numid - kctl->id.numid;
166 	return array_index_nospec(ioff, kctl->count);
167 }
168 
169 static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
170 {
171 	unsigned int ioff = id->index - kctl->id.index;
172 	return array_index_nospec(ioff, kctl->count);
173 }
174 
175 static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
176 {
177 	if (id->numid) {
178 		return snd_ctl_get_ioffnum(kctl, id);
179 	} else {
180 		return snd_ctl_get_ioffidx(kctl, id);
181 	}
182 }
183 
184 static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id *dst_id,
185 						    struct snd_kcontrol *src_kctl,
186 						    unsigned int offset)
187 {
188 	*dst_id = src_kctl->id;
189 	dst_id->index += offset;
190 	dst_id->numid += offset;
191 	return dst_id;
192 }
193 
194 /*
195  * Frequently used control callbacks/helpers
196  */
197 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
198 			      struct snd_ctl_elem_info *uinfo);
199 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
200 				struct snd_ctl_elem_info *uinfo);
201 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
202 		      unsigned int items, const char *const names[]);
203 
204 /*
205  * virtual master control
206  */
207 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
208 						 const unsigned int *tlv);
209 int _snd_ctl_add_follower(struct snd_kcontrol *master,
210 			  struct snd_kcontrol *follower,
211 			  unsigned int flags);
212 /* optional flags for follower */
213 #define SND_CTL_FOLLOWER_NEED_UPDATE	(1 << 0)
214 
215 /**
216  * snd_ctl_add_follower - Add a virtual follower control
217  * @master: vmaster element
218  * @follower: follower element to add
219  *
220  * Add a virtual follower control to the given master element created via
221  * snd_ctl_create_virtual_master() beforehand.
222  *
223  * All followers must be the same type (returning the same information
224  * via info callback).  The function doesn't check it, so it's your
225  * responsibility.
226  *
227  * Also, some additional limitations:
228  * at most two channels,
229  * logarithmic volume control (dB level) thus no linear volume,
230  * master can only attenuate the volume without gain
231  *
232  * Return: Zero if successful or a negative error code.
233  */
234 static inline int
235 snd_ctl_add_follower(struct snd_kcontrol *master, struct snd_kcontrol *follower)
236 {
237 	return _snd_ctl_add_follower(master, follower, 0);
238 }
239 
240 /**
241  * snd_ctl_add_follower_uncached - Add a virtual follower control
242  * @master: vmaster element
243  * @follower: follower element to add
244  *
245  * Add a virtual follower control to the given master.
246  * Unlike snd_ctl_add_follower(), the element added via this function
247  * is supposed to have volatile values, and get callback is called
248  * at each time queried from the master.
249  *
250  * When the control peeks the hardware values directly and the value
251  * can be changed by other means than the put callback of the element,
252  * this function should be used to keep the value always up-to-date.
253  *
254  * Return: Zero if successful or a negative error code.
255  */
256 static inline int
257 snd_ctl_add_follower_uncached(struct snd_kcontrol *master,
258 			      struct snd_kcontrol *follower)
259 {
260 	return _snd_ctl_add_follower(master, follower, SND_CTL_FOLLOWER_NEED_UPDATE);
261 }
262 
263 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
264 			     void (*hook)(void *private_data, int),
265 			     void *private_data);
266 void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
267 #define snd_ctl_sync_vmaster_hook(kctl)	snd_ctl_sync_vmaster(kctl, true)
268 int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
269 				    int (*func)(struct snd_kcontrol *vfollower,
270 						struct snd_kcontrol *follower,
271 						void *arg),
272 				    void *arg);
273 
274 /*
275  * Control LED trigger layer
276  */
277 #define SND_CTL_LAYER_MODULE_LED	"snd-ctl-led"
278 
279 #if IS_MODULE(CONFIG_SND_CTL_LED)
280 static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
281 #else
282 static inline int snd_ctl_led_request(void) { return 0; }
283 #endif
284 
285 /*
286  * Helper functions for jack-detection controls
287  */
288 struct snd_kcontrol *
289 snd_kctl_jack_new(const char *name, struct snd_card *card);
290 void snd_kctl_jack_report(struct snd_card *card,
291 			  struct snd_kcontrol *kctl, bool status);
292 
293 #endif	/* __SOUND_CONTROL_H */
294