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 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, struct snd_ctl_elem_id *id);
145 
146 int snd_ctl_create(struct snd_card *card);
147 
148 int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn);
149 int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn);
150 #ifdef CONFIG_COMPAT
151 int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn);
152 int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn);
153 #else
154 #define snd_ctl_register_ioctl_compat(fcn)
155 #define snd_ctl_unregister_ioctl_compat(fcn)
156 #endif
157 
158 int snd_ctl_request_layer(const char *module_name);
159 void snd_ctl_register_layer(struct snd_ctl_layer_ops *lops);
160 void snd_ctl_disconnect_layer(struct snd_ctl_layer_ops *lops);
161 
162 int snd_ctl_get_preferred_subdevice(struct snd_card *card, int type);
163 
snd_ctl_get_ioffnum(struct snd_kcontrol * kctl,struct snd_ctl_elem_id * id)164 static inline unsigned int snd_ctl_get_ioffnum(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
165 {
166 	unsigned int ioff = id->numid - kctl->id.numid;
167 	return array_index_nospec(ioff, kctl->count);
168 }
169 
snd_ctl_get_ioffidx(struct snd_kcontrol * kctl,struct snd_ctl_elem_id * id)170 static inline unsigned int snd_ctl_get_ioffidx(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
171 {
172 	unsigned int ioff = id->index - kctl->id.index;
173 	return array_index_nospec(ioff, kctl->count);
174 }
175 
snd_ctl_get_ioff(struct snd_kcontrol * kctl,struct snd_ctl_elem_id * id)176 static inline unsigned int snd_ctl_get_ioff(struct snd_kcontrol *kctl, struct snd_ctl_elem_id *id)
177 {
178 	if (id->numid) {
179 		return snd_ctl_get_ioffnum(kctl, id);
180 	} else {
181 		return snd_ctl_get_ioffidx(kctl, id);
182 	}
183 }
184 
snd_ctl_build_ioff(struct snd_ctl_elem_id * dst_id,struct snd_kcontrol * src_kctl,unsigned int offset)185 static inline struct snd_ctl_elem_id *snd_ctl_build_ioff(struct snd_ctl_elem_id *dst_id,
186 						    struct snd_kcontrol *src_kctl,
187 						    unsigned int offset)
188 {
189 	*dst_id = src_kctl->id;
190 	dst_id->index += offset;
191 	dst_id->numid += offset;
192 	return dst_id;
193 }
194 
195 /*
196  * Frequently used control callbacks/helpers
197  */
198 int snd_ctl_boolean_mono_info(struct snd_kcontrol *kcontrol,
199 			      struct snd_ctl_elem_info *uinfo);
200 int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol,
201 				struct snd_ctl_elem_info *uinfo);
202 int snd_ctl_enum_info(struct snd_ctl_elem_info *info, unsigned int channels,
203 		      unsigned int items, const char *const names[]);
204 
205 /*
206  * virtual master control
207  */
208 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
209 						 const unsigned int *tlv);
210 int _snd_ctl_add_follower(struct snd_kcontrol *master,
211 			  struct snd_kcontrol *follower,
212 			  unsigned int flags);
213 /* optional flags for follower */
214 #define SND_CTL_FOLLOWER_NEED_UPDATE	(1 << 0)
215 
216 /**
217  * snd_ctl_add_follower - Add a virtual follower control
218  * @master: vmaster element
219  * @follower: follower element to add
220  *
221  * Add a virtual follower control to the given master element created via
222  * snd_ctl_create_virtual_master() beforehand.
223  *
224  * All followers must be the same type (returning the same information
225  * via info callback).  The function doesn't check it, so it's your
226  * responsibility.
227  *
228  * Also, some additional limitations:
229  * at most two channels,
230  * logarithmic volume control (dB level) thus no linear volume,
231  * master can only attenuate the volume without gain
232  *
233  * Return: Zero if successful or a negative error code.
234  */
235 static inline int
snd_ctl_add_follower(struct snd_kcontrol * master,struct snd_kcontrol * follower)236 snd_ctl_add_follower(struct snd_kcontrol *master, struct snd_kcontrol *follower)
237 {
238 	return _snd_ctl_add_follower(master, follower, 0);
239 }
240 
241 /**
242  * snd_ctl_add_follower_uncached - Add a virtual follower control
243  * @master: vmaster element
244  * @follower: follower element to add
245  *
246  * Add a virtual follower control to the given master.
247  * Unlike snd_ctl_add_follower(), the element added via this function
248  * is supposed to have volatile values, and get callback is called
249  * at each time queried from the master.
250  *
251  * When the control peeks the hardware values directly and the value
252  * can be changed by other means than the put callback of the element,
253  * this function should be used to keep the value always up-to-date.
254  *
255  * Return: Zero if successful or a negative error code.
256  */
257 static inline int
snd_ctl_add_follower_uncached(struct snd_kcontrol * master,struct snd_kcontrol * follower)258 snd_ctl_add_follower_uncached(struct snd_kcontrol *master,
259 			      struct snd_kcontrol *follower)
260 {
261 	return _snd_ctl_add_follower(master, follower, SND_CTL_FOLLOWER_NEED_UPDATE);
262 }
263 
264 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl,
265 			     void (*hook)(void *private_data, int),
266 			     void *private_data);
267 void snd_ctl_sync_vmaster(struct snd_kcontrol *kctl, bool hook_only);
268 #define snd_ctl_sync_vmaster_hook(kctl)	snd_ctl_sync_vmaster(kctl, true)
269 int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
270 				    int (*func)(struct snd_kcontrol *vfollower,
271 						struct snd_kcontrol *follower,
272 						void *arg),
273 				    void *arg);
274 
275 /*
276  * Control LED trigger layer
277  */
278 #define SND_CTL_LAYER_MODULE_LED	"snd-ctl-led"
279 
280 #if IS_MODULE(CONFIG_SND_CTL_LED)
snd_ctl_led_request(void)281 static inline int snd_ctl_led_request(void) { return snd_ctl_request_layer(SND_CTL_LAYER_MODULE_LED); }
282 #else
snd_ctl_led_request(void)283 static inline int snd_ctl_led_request(void) { return 0; }
284 #endif
285 
286 /*
287  * Helper functions for jack-detection controls
288  */
289 struct snd_kcontrol *
290 snd_kctl_jack_new(const char *name, struct snd_card *card);
291 void snd_kctl_jack_report(struct snd_card *card,
292 			  struct snd_kcontrol *kctl, bool status);
293 
294 #endif	/* __SOUND_CONTROL_H */
295