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22d8de62 JK |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * LED state routines for driver control interface | |
4 | * Copyright (c) 2021 by Jaroslav Kysela <perex@perex.cz> | |
5 | */ | |
6 | ||
7 | #include <linux/slab.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/leds.h> | |
10 | #include <sound/core.h> | |
11 | #include <sound/control.h> | |
12 | ||
13 | MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); | |
14 | MODULE_DESCRIPTION("ALSA control interface to LED trigger code."); | |
15 | MODULE_LICENSE("GPL"); | |
16 | ||
17 | #define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \ | |
18 | >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1) | |
19 | ||
20 | struct snd_ctl_led { | |
21 | struct list_head list; | |
22 | struct snd_card *card; | |
23 | unsigned int access; | |
24 | struct snd_kcontrol *kctl; | |
25 | unsigned int index_offset; | |
26 | }; | |
27 | ||
28 | static DEFINE_MUTEX(snd_ctl_led_mutex); | |
29 | static struct list_head snd_ctl_led_controls[MAX_LED]; | |
30 | static bool snd_ctl_led_card_valid[SNDRV_CARDS]; | |
31 | ||
32 | #define UPDATE_ROUTE(route, cb) \ | |
33 | do { \ | |
34 | int route2 = (cb); \ | |
35 | if (route2 >= 0) \ | |
36 | route = route < 0 ? route2 : (route | route2); \ | |
37 | } while (0) | |
38 | ||
39 | static inline unsigned int access_to_group(unsigned int access) | |
40 | { | |
41 | return ((access & SNDRV_CTL_ELEM_ACCESS_LED_MASK) >> | |
42 | SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1; | |
43 | } | |
44 | ||
45 | static inline unsigned int group_to_access(unsigned int group) | |
46 | { | |
47 | return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT; | |
48 | } | |
49 | ||
50 | static struct list_head *snd_ctl_led_controls_by_access(unsigned int access) | |
51 | { | |
52 | unsigned int group = access_to_group(access); | |
53 | if (group >= MAX_LED) | |
54 | return NULL; | |
55 | return &snd_ctl_led_controls[group]; | |
56 | } | |
57 | ||
58 | static int snd_ctl_led_get(struct snd_ctl_led *lctl) | |
59 | { | |
60 | struct snd_kcontrol *kctl = lctl->kctl; | |
61 | struct snd_ctl_elem_info info; | |
62 | struct snd_ctl_elem_value value; | |
63 | unsigned int i; | |
64 | int result; | |
65 | ||
66 | memset(&info, 0, sizeof(info)); | |
67 | info.id = kctl->id; | |
68 | info.id.index += lctl->index_offset; | |
69 | info.id.numid += lctl->index_offset; | |
70 | result = kctl->info(kctl, &info); | |
71 | if (result < 0) | |
72 | return -1; | |
73 | memset(&value, 0, sizeof(value)); | |
74 | value.id = info.id; | |
75 | result = kctl->get(kctl, &value); | |
76 | if (result < 0) | |
77 | return -1; | |
78 | if (info.type == SNDRV_CTL_ELEM_TYPE_BOOLEAN || | |
79 | info.type == SNDRV_CTL_ELEM_TYPE_INTEGER) { | |
80 | for (i = 0; i < info.count; i++) | |
81 | if (value.value.integer.value[i] != info.value.integer.min) | |
82 | return 1; | |
83 | } else if (info.type == SNDRV_CTL_ELEM_TYPE_INTEGER64) { | |
84 | for (i = 0; i < info.count; i++) | |
85 | if (value.value.integer64.value[i] != info.value.integer64.min) | |
86 | return 1; | |
87 | } | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access, | |
92 | struct snd_kcontrol *kctl, unsigned int ioff) | |
93 | { | |
94 | struct list_head *controls; | |
95 | struct snd_ctl_led *lctl; | |
96 | enum led_audio led_trigger_type; | |
97 | int route; | |
98 | bool found; | |
99 | ||
100 | controls = snd_ctl_led_controls_by_access(access); | |
101 | if (!controls) | |
102 | return; | |
103 | if (access == SNDRV_CTL_ELEM_ACCESS_SPK_LED) { | |
104 | led_trigger_type = LED_AUDIO_MUTE; | |
105 | } else if (access == SNDRV_CTL_ELEM_ACCESS_MIC_LED) { | |
106 | led_trigger_type = LED_AUDIO_MICMUTE; | |
107 | } else { | |
108 | return; | |
109 | } | |
110 | route = -1; | |
111 | found = false; | |
112 | mutex_lock(&snd_ctl_led_mutex); | |
113 | /* the card may not be registered (active) at this point */ | |
114 | if (card && !snd_ctl_led_card_valid[card->number]) { | |
115 | mutex_unlock(&snd_ctl_led_mutex); | |
116 | return; | |
117 | } | |
118 | list_for_each_entry(lctl, controls, list) { | |
119 | if (lctl->kctl == kctl && lctl->index_offset == ioff) | |
120 | found = true; | |
121 | UPDATE_ROUTE(route, snd_ctl_led_get(lctl)); | |
122 | } | |
123 | if (!found && kctl && card) { | |
124 | lctl = kzalloc(sizeof(*lctl), GFP_KERNEL); | |
125 | if (lctl) { | |
126 | lctl->card = card; | |
127 | lctl->access = access; | |
128 | lctl->kctl = kctl; | |
129 | lctl->index_offset = ioff; | |
130 | list_add(&lctl->list, controls); | |
131 | UPDATE_ROUTE(route, snd_ctl_led_get(lctl)); | |
132 | } | |
133 | } | |
134 | mutex_unlock(&snd_ctl_led_mutex); | |
135 | if (route >= 0) | |
136 | ledtrig_audio_set(led_trigger_type, route ? LED_OFF : LED_ON); | |
137 | } | |
138 | ||
139 | static struct snd_ctl_led *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff) | |
140 | { | |
141 | struct list_head *controls; | |
142 | struct snd_ctl_led *lctl; | |
143 | unsigned int group; | |
144 | ||
145 | for (group = 0; group < MAX_LED; group++) { | |
146 | controls = &snd_ctl_led_controls[group]; | |
147 | list_for_each_entry(lctl, controls, list) | |
148 | if (lctl->kctl == kctl && lctl->index_offset == ioff) | |
149 | return lctl; | |
150 | } | |
151 | return NULL; | |
152 | } | |
153 | ||
154 | static unsigned int snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff, | |
155 | unsigned int access) | |
156 | { | |
157 | struct snd_ctl_led *lctl; | |
158 | unsigned int ret = 0; | |
159 | ||
160 | mutex_lock(&snd_ctl_led_mutex); | |
161 | lctl = snd_ctl_led_find(kctl, ioff); | |
162 | if (lctl && (access == 0 || access != lctl->access)) { | |
163 | ret = lctl->access; | |
164 | list_del(&lctl->list); | |
165 | kfree(lctl); | |
166 | } | |
167 | mutex_unlock(&snd_ctl_led_mutex); | |
168 | return ret; | |
169 | } | |
170 | ||
171 | static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask, | |
172 | struct snd_kcontrol *kctl, unsigned int ioff) | |
173 | { | |
174 | struct snd_kcontrol_volatile *vd; | |
175 | unsigned int access, access2; | |
176 | ||
177 | if (mask == SNDRV_CTL_EVENT_MASK_REMOVE) { | |
178 | access = snd_ctl_led_remove(kctl, ioff, 0); | |
179 | if (access) | |
180 | snd_ctl_led_set_state(card, access, NULL, 0); | |
181 | } else if (mask & SNDRV_CTL_EVENT_MASK_INFO) { | |
182 | vd = &kctl->vd[ioff]; | |
183 | access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK; | |
184 | access2 = snd_ctl_led_remove(kctl, ioff, access); | |
185 | if (access2) | |
186 | snd_ctl_led_set_state(card, access2, NULL, 0); | |
187 | if (access) | |
188 | snd_ctl_led_set_state(card, access, kctl, ioff); | |
189 | } else if ((mask & (SNDRV_CTL_EVENT_MASK_ADD | | |
190 | SNDRV_CTL_EVENT_MASK_VALUE)) != 0) { | |
191 | vd = &kctl->vd[ioff]; | |
192 | access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK; | |
193 | if (access) | |
194 | snd_ctl_led_set_state(card, access, kctl, ioff); | |
195 | } | |
196 | } | |
197 | ||
198 | static void snd_ctl_led_refresh(void) | |
199 | { | |
200 | unsigned int group; | |
201 | ||
202 | for (group = 0; group < MAX_LED; group++) | |
203 | snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0); | |
204 | } | |
205 | ||
206 | static void snd_ctl_led_clean(struct snd_card *card) | |
207 | { | |
208 | unsigned int group; | |
209 | struct list_head *controls; | |
210 | struct snd_ctl_led *lctl; | |
211 | ||
212 | for (group = 0; group < MAX_LED; group++) { | |
213 | controls = &snd_ctl_led_controls[group]; | |
214 | repeat: | |
215 | list_for_each_entry(lctl, controls, list) | |
216 | if (!card || lctl->card == card) { | |
217 | list_del(&lctl->list); | |
218 | kfree(lctl); | |
219 | goto repeat; | |
220 | } | |
221 | } | |
222 | } | |
223 | ||
224 | static void snd_ctl_led_register(struct snd_card *card) | |
225 | { | |
226 | struct snd_kcontrol *kctl; | |
227 | unsigned int ioff; | |
228 | ||
229 | if (snd_BUG_ON(card->number < 0 || | |
230 | card->number >= ARRAY_SIZE(snd_ctl_led_card_valid))) | |
231 | return; | |
232 | mutex_lock(&snd_ctl_led_mutex); | |
233 | snd_ctl_led_card_valid[card->number] = true; | |
234 | mutex_unlock(&snd_ctl_led_mutex); | |
235 | /* the register callback is already called with held card->controls_rwsem */ | |
236 | list_for_each_entry(kctl, &card->controls, list) | |
237 | for (ioff = 0; ioff < kctl->count; ioff++) | |
238 | snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff); | |
239 | snd_ctl_led_refresh(); | |
240 | } | |
241 | ||
242 | static void snd_ctl_led_disconnect(struct snd_card *card) | |
243 | { | |
244 | mutex_lock(&snd_ctl_led_mutex); | |
245 | snd_ctl_led_card_valid[card->number] = false; | |
246 | snd_ctl_led_clean(card); | |
247 | mutex_unlock(&snd_ctl_led_mutex); | |
248 | snd_ctl_led_refresh(); | |
249 | } | |
250 | ||
251 | /* | |
252 | * Control layer registration | |
253 | */ | |
254 | static struct snd_ctl_layer_ops snd_ctl_led_lops = { | |
255 | .module_name = SND_CTL_LAYER_MODULE_LED, | |
256 | .lregister = snd_ctl_led_register, | |
257 | .ldisconnect = snd_ctl_led_disconnect, | |
258 | .lnotify = snd_ctl_led_notify, | |
259 | }; | |
260 | ||
261 | static int __init snd_ctl_led_init(void) | |
262 | { | |
263 | unsigned int group; | |
264 | ||
265 | for (group = 0; group < MAX_LED; group++) | |
266 | INIT_LIST_HEAD(&snd_ctl_led_controls[group]); | |
267 | snd_ctl_register_layer(&snd_ctl_led_lops); | |
268 | return 0; | |
269 | } | |
270 | ||
271 | static void __exit snd_ctl_led_exit(void) | |
272 | { | |
273 | snd_ctl_disconnect_layer(&snd_ctl_led_lops); | |
274 | snd_ctl_led_clean(NULL); | |
275 | } | |
276 | ||
277 | module_init(snd_ctl_led_init) | |
278 | module_exit(snd_ctl_led_exit) |