1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Virtual master and follower controls
4 *
5 * Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
6 */
7
8#include <linux/slab.h>
9#include <linux/export.h>
10#include <sound/core.h>
11#include <sound/control.h>
12#include <sound/tlv.h>
13
14/*
15 * a subset of information returned via ctl info callback
16 */
17struct link_ctl_info {
18 snd_ctl_elem_type_t type; /* value type */
19 int count; /* item count */
20 int min_val, max_val; /* min, max values */
21};
22
23/*
24 * link master - this contains a list of follower controls that are
25 * identical types, i.e. info returns the same value type and value
26 * ranges, but may have different number of counts.
27 *
28 * The master control is so far only mono volume/switch for simplicity.
29 * The same value will be applied to all followers.
30 */
31struct link_master {
32 struct list_head followers;
33 struct link_ctl_info info;
34 int val; /* the master value */
35 unsigned int tlv[4];
36 void (*hook)(void *private_data, int);
37 void *hook_private_data;
38};
39
40/*
41 * link follower - this contains a follower control element
42 *
43 * It fakes the control callbacks with additional attenuation by the
44 * master control. A follower may have either one or two channels.
45 */
46
47struct link_follower {
48 struct list_head list;
49 struct link_master *master;
50 struct link_ctl_info info;
51 int vals[2]; /* current values */
52 unsigned int flags;
53 struct snd_kcontrol *kctl; /* original kcontrol pointer */
54 struct snd_kcontrol follower; /* the copy of original control entry */
55};
56
57static int follower_update(struct link_follower *follower)
58{
59 struct snd_ctl_elem_value *uctl __free(kfree) = NULL;
60 int err, ch;
61
62 uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
63 if (!uctl)
64 return -ENOMEM;
65 uctl->id = follower->follower.id;
66 err = follower->follower.get(&follower->follower, uctl);
67 if (err < 0)
68 return err;
69 for (ch = 0; ch < follower->info.count; ch++)
70 follower->vals[ch] = uctl->value.integer.value[ch];
71 return 0;
72}
73
74/* get the follower ctl info and save the initial values */
75static int follower_init(struct link_follower *follower)
76{
77 struct snd_ctl_elem_info *uinfo __free(kfree) = NULL;
78 int err;
79
80 if (follower->info.count) {
81 /* already initialized */
82 if (follower->flags & SND_CTL_FOLLOWER_NEED_UPDATE)
83 return follower_update(follower);
84 return 0;
85 }
86
87 uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
88 if (!uinfo)
89 return -ENOMEM;
90 uinfo->id = follower->follower.id;
91 err = follower->follower.info(&follower->follower, uinfo);
92 if (err < 0)
93 return err;
94 follower->info.type = uinfo->type;
95 follower->info.count = uinfo->count;
96 if (follower->info.count > 2 ||
97 (follower->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
98 follower->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
99 pr_err("ALSA: vmaster: invalid follower element\n");
100 return -EINVAL;
101 }
102 follower->info.min_val = uinfo->value.integer.min;
103 follower->info.max_val = uinfo->value.integer.max;
104
105 return follower_update(follower);
106}
107
108/* initialize master volume */
109static int master_init(struct link_master *master)
110{
111 struct link_follower *follower;
112
113 if (master->info.count)
114 return 0; /* already initialized */
115
116 list_for_each_entry(follower, &master->followers, list) {
117 int err = follower_init(follower);
118 if (err < 0)
119 return err;
120 master->info = follower->info;
121 master->info.count = 1; /* always mono */
122 /* set full volume as default (= no attenuation) */
123 master->val = master->info.max_val;
124 if (master->hook)
125 master->hook(master->hook_private_data, master->val);
126 return 1;
127 }
128 return -ENOENT;
129}
130
131static int follower_get_val(struct link_follower *follower,
132 struct snd_ctl_elem_value *ucontrol)
133{
134 int err, ch;
135
136 err = follower_init(follower);
137 if (err < 0)
138 return err;
139 for (ch = 0; ch < follower->info.count; ch++)
140 ucontrol->value.integer.value[ch] = follower->vals[ch];
141 return 0;
142}
143
144static int follower_put_val(struct link_follower *follower,
145 struct snd_ctl_elem_value *ucontrol)
146{
147 int err, ch, vol;
148
149 err = master_init(master: follower->master);
150 if (err < 0)
151 return err;
152
153 switch (follower->info.type) {
154 case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
155 for (ch = 0; ch < follower->info.count; ch++)
156 ucontrol->value.integer.value[ch] &=
157 !!follower->master->val;
158 break;
159 case SNDRV_CTL_ELEM_TYPE_INTEGER:
160 for (ch = 0; ch < follower->info.count; ch++) {
161 /* max master volume is supposed to be 0 dB */
162 vol = ucontrol->value.integer.value[ch];
163 vol += follower->master->val - follower->master->info.max_val;
164 if (vol < follower->info.min_val)
165 vol = follower->info.min_val;
166 else if (vol > follower->info.max_val)
167 vol = follower->info.max_val;
168 ucontrol->value.integer.value[ch] = vol;
169 }
170 break;
171 }
172 return follower->follower.put(&follower->follower, ucontrol);
173}
174
175/*
176 * ctl callbacks for followers
177 */
178static int follower_info(struct snd_kcontrol *kcontrol,
179 struct snd_ctl_elem_info *uinfo)
180{
181 struct link_follower *follower = snd_kcontrol_chip(kcontrol);
182 return follower->follower.info(&follower->follower, uinfo);
183}
184
185static int follower_get(struct snd_kcontrol *kcontrol,
186 struct snd_ctl_elem_value *ucontrol)
187{
188 struct link_follower *follower = snd_kcontrol_chip(kcontrol);
189 return follower_get_val(follower, ucontrol);
190}
191
192static int follower_put(struct snd_kcontrol *kcontrol,
193 struct snd_ctl_elem_value *ucontrol)
194{
195 struct link_follower *follower = snd_kcontrol_chip(kcontrol);
196 int err, ch, changed = 0;
197
198 err = follower_init(follower);
199 if (err < 0)
200 return err;
201 for (ch = 0; ch < follower->info.count; ch++) {
202 if (ucontrol->value.integer.value[ch] < follower->info.min_val ||
203 ucontrol->value.integer.value[ch] > follower->info.max_val)
204 return -EINVAL;
205 }
206
207 for (ch = 0; ch < follower->info.count; ch++) {
208 if (follower->vals[ch] != ucontrol->value.integer.value[ch]) {
209 changed = 1;
210 follower->vals[ch] = ucontrol->value.integer.value[ch];
211 }
212 }
213 if (!changed)
214 return 0;
215 err = follower_put_val(follower, ucontrol);
216 if (err < 0)
217 return err;
218 return 1;
219}
220
221static int follower_tlv_cmd(struct snd_kcontrol *kcontrol,
222 int op_flag, unsigned int size,
223 unsigned int __user *tlv)
224{
225 struct link_follower *follower = snd_kcontrol_chip(kcontrol);
226 /* FIXME: this assumes that the max volume is 0 dB */
227 return follower->follower.tlv.c(&follower->follower, op_flag, size, tlv);
228}
229
230static void follower_free(struct snd_kcontrol *kcontrol)
231{
232 struct link_follower *follower = snd_kcontrol_chip(kcontrol);
233 if (follower->follower.private_free)
234 follower->follower.private_free(&follower->follower);
235 if (follower->master)
236 list_del(entry: &follower->list);
237 kfree(objp: follower);
238}
239
240/*
241 * Add a follower control to the group with the given master control
242 *
243 * All followers must be the same type (returning the same information
244 * via info callback). The function doesn't check it, so it's your
245 * responsibility.
246 *
247 * Also, some additional limitations:
248 * - at most two channels
249 * - logarithmic volume control (dB level), no linear volume
250 * - master can only attenuate the volume, no gain
251 */
252int _snd_ctl_add_follower(struct snd_kcontrol *master,
253 struct snd_kcontrol *follower,
254 unsigned int flags)
255{
256 struct link_master *master_link = snd_kcontrol_chip(master);
257 struct link_follower *srec;
258
259 srec = kzalloc(struct_size(srec, follower.vd, follower->count),
260 GFP_KERNEL);
261 if (!srec)
262 return -ENOMEM;
263 srec->kctl = follower;
264 srec->follower = *follower;
265 memcpy(to: srec->follower.vd, from: follower->vd, len: follower->count * sizeof(*follower->vd));
266 srec->master = master_link;
267 srec->flags = flags;
268
269 /* override callbacks */
270 follower->info = follower_info;
271 follower->get = follower_get;
272 follower->put = follower_put;
273 if (follower->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
274 follower->tlv.c = follower_tlv_cmd;
275 follower->private_data = srec;
276 follower->private_free = follower_free;
277
278 list_add_tail(new: &srec->list, head: &master_link->followers);
279 return 0;
280}
281EXPORT_SYMBOL(_snd_ctl_add_follower);
282
283/**
284 * snd_ctl_add_followers - add multiple followers to vmaster
285 * @card: card instance
286 * @master: the target vmaster kcontrol object
287 * @list: NULL-terminated list of name strings of followers to be added
288 *
289 * Adds the multiple follower kcontrols with the given names.
290 * Returns 0 for success or a negative error code.
291 */
292int snd_ctl_add_followers(struct snd_card *card, struct snd_kcontrol *master,
293 const char * const *list)
294{
295 struct snd_kcontrol *follower;
296 int err;
297
298 for (; *list; list++) {
299 follower = snd_ctl_find_id_mixer(card, name: *list);
300 if (follower) {
301 err = snd_ctl_add_follower(master, follower);
302 if (err < 0)
303 return err;
304 }
305 }
306
307 return 0;
308}
309EXPORT_SYMBOL_GPL(snd_ctl_add_followers);
310
311/*
312 * ctl callbacks for master controls
313 */
314static int master_info(struct snd_kcontrol *kcontrol,
315 struct snd_ctl_elem_info *uinfo)
316{
317 struct link_master *master = snd_kcontrol_chip(kcontrol);
318 int ret;
319
320 ret = master_init(master);
321 if (ret < 0)
322 return ret;
323 uinfo->type = master->info.type;
324 uinfo->count = master->info.count;
325 uinfo->value.integer.min = master->info.min_val;
326 uinfo->value.integer.max = master->info.max_val;
327 return 0;
328}
329
330static int master_get(struct snd_kcontrol *kcontrol,
331 struct snd_ctl_elem_value *ucontrol)
332{
333 struct link_master *master = snd_kcontrol_chip(kcontrol);
334 int err = master_init(master);
335 if (err < 0)
336 return err;
337 ucontrol->value.integer.value[0] = master->val;
338 return 0;
339}
340
341static int sync_followers(struct link_master *master, int old_val, int new_val)
342{
343 struct link_follower *follower;
344 struct snd_ctl_elem_value *uval __free(kfree) = NULL;
345
346 uval = kmalloc(sizeof(*uval), GFP_KERNEL);
347 if (!uval)
348 return -ENOMEM;
349 list_for_each_entry(follower, &master->followers, list) {
350 master->val = old_val;
351 uval->id = follower->follower.id;
352 follower_get_val(follower, ucontrol: uval);
353 master->val = new_val;
354 follower_put_val(follower, ucontrol: uval);
355 }
356 return 0;
357}
358
359static int master_put(struct snd_kcontrol *kcontrol,
360 struct snd_ctl_elem_value *ucontrol)
361{
362 struct link_master *master = snd_kcontrol_chip(kcontrol);
363 int err, new_val, old_val;
364 bool first_init;
365
366 err = master_init(master);
367 if (err < 0)
368 return err;
369 first_init = err;
370 old_val = master->val;
371 new_val = ucontrol->value.integer.value[0];
372 if (new_val == old_val)
373 return 0;
374 if (new_val < master->info.min_val || new_val > master->info.max_val)
375 return -EINVAL;
376
377 err = sync_followers(master, old_val, new_val);
378 if (err < 0)
379 return err;
380 if (master->hook && !first_init)
381 master->hook(master->hook_private_data, master->val);
382 return 1;
383}
384
385static void master_free(struct snd_kcontrol *kcontrol)
386{
387 struct link_master *master = snd_kcontrol_chip(kcontrol);
388 struct link_follower *follower, *n;
389
390 /* free all follower links and retore the original follower kctls */
391 list_for_each_entry_safe(follower, n, &master->followers, list) {
392 struct snd_kcontrol *sctl = follower->kctl;
393 struct list_head olist = sctl->list;
394 memcpy(to: sctl, from: &follower->follower, len: sizeof(*sctl));
395 memcpy(to: sctl->vd, from: follower->follower.vd,
396 len: sctl->count * sizeof(*sctl->vd));
397 sctl->list = olist; /* keep the current linked-list */
398 kfree(objp: follower);
399 }
400 kfree(objp: master);
401}
402
403
404/**
405 * snd_ctl_make_virtual_master - Create a virtual master control
406 * @name: name string of the control element to create
407 * @tlv: optional TLV int array for dB information
408 *
409 * Creates a virtual master control with the given name string.
410 *
411 * After creating a vmaster element, you can add the follower controls
412 * via snd_ctl_add_follower() or snd_ctl_add_follower_uncached().
413 *
414 * The optional argument @tlv can be used to specify the TLV information
415 * for dB scale of the master control. It should be a single element
416 * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
417 * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
418 *
419 * Return: The created control element, or %NULL for errors (ENOMEM).
420 */
421struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
422 const unsigned int *tlv)
423{
424 struct link_master *master;
425 struct snd_kcontrol *kctl;
426 struct snd_kcontrol_new knew;
427
428 memset(s: &knew, c: 0, n: sizeof(knew));
429 knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
430 knew.name = name;
431 knew.info = master_info;
432
433 master = kzalloc(sizeof(*master), GFP_KERNEL);
434 if (!master)
435 return NULL;
436 INIT_LIST_HEAD(list: &master->followers);
437
438 kctl = snd_ctl_new1(kcontrolnew: &knew, private_data: master);
439 if (!kctl) {
440 kfree(objp: master);
441 return NULL;
442 }
443 /* override some callbacks */
444 kctl->info = master_info;
445 kctl->get = master_get;
446 kctl->put = master_put;
447 kctl->private_free = master_free;
448
449 /* additional (constant) TLV read */
450 if (tlv) {
451 unsigned int type = tlv[SNDRV_CTL_TLVO_TYPE];
452 if (type == SNDRV_CTL_TLVT_DB_SCALE ||
453 type == SNDRV_CTL_TLVT_DB_MINMAX ||
454 type == SNDRV_CTL_TLVT_DB_MINMAX_MUTE) {
455 kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
456 memcpy(to: master->tlv, from: tlv, len: sizeof(master->tlv));
457 kctl->tlv.p = master->tlv;
458 }
459 }
460
461 return kctl;
462}
463EXPORT_SYMBOL(snd_ctl_make_virtual_master);
464
465/**
466 * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
467 * @kcontrol: vmaster kctl element
468 * @hook: the hook function
469 * @private_data: the private_data pointer to be saved
470 *
471 * Adds the given hook to the vmaster control element so that it's called
472 * at each time when the value is changed.
473 *
474 * Return: Zero.
475 */
476int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
477 void (*hook)(void *private_data, int),
478 void *private_data)
479{
480 struct link_master *master = snd_kcontrol_chip(kcontrol);
481 master->hook = hook;
482 master->hook_private_data = private_data;
483 return 0;
484}
485EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);
486
487/**
488 * snd_ctl_sync_vmaster - Sync the vmaster followers and hook
489 * @kcontrol: vmaster kctl element
490 * @hook_only: sync only the hook
491 *
492 * Forcibly call the put callback of each follower and call the hook function
493 * to synchronize with the current value of the given vmaster element.
494 * NOP when NULL is passed to @kcontrol.
495 */
496void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
497{
498 struct link_master *master;
499 bool first_init = false;
500
501 if (!kcontrol)
502 return;
503 master = snd_kcontrol_chip(kcontrol);
504 if (!hook_only) {
505 int err = master_init(master);
506 if (err < 0)
507 return;
508 first_init = err;
509 err = sync_followers(master, old_val: master->val, new_val: master->val);
510 if (err < 0)
511 return;
512 }
513
514 if (master->hook && !first_init)
515 master->hook(master->hook_private_data, master->val);
516}
517EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);
518
519/**
520 * snd_ctl_apply_vmaster_followers - Apply function to each vmaster follower
521 * @kctl: vmaster kctl element
522 * @func: function to apply
523 * @arg: optional function argument
524 *
525 * Apply the function @func to each follower kctl of the given vmaster kctl.
526 *
527 * Return: 0 if successful, or a negative error code
528 */
529int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
530 int (*func)(struct snd_kcontrol *vfollower,
531 struct snd_kcontrol *follower,
532 void *arg),
533 void *arg)
534{
535 struct link_master *master;
536 struct link_follower *follower;
537 int err;
538
539 master = snd_kcontrol_chip(kctl);
540 err = master_init(master);
541 if (err < 0)
542 return err;
543 list_for_each_entry(follower, &master->followers, list) {
544 err = func(follower->kctl, &follower->follower, arg);
545 if (err < 0)
546 return err;
547 }
548
549 return 0;
550}
551EXPORT_SYMBOL_GPL(snd_ctl_apply_vmaster_followers);
552