1 /*-
2 * Copyright (c) 2021 Christos Margiolis <christos@FreeBSD.org>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23 #include <sys/types.h>
24 #include <sys/ioctl.h>
25 #include <sys/sysctl.h>
26
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33
34 #include "mixer.h"
35
36 #define BASEPATH "/dev/mixer"
37
38 static int _mixer_readvol(struct mix_dev *);
39
40 /*
41 * Fetch volume from the device.
42 */
43 static int
_mixer_readvol(struct mix_dev * dev)44 _mixer_readvol(struct mix_dev *dev)
45 {
46 int v;
47
48 if (ioctl(dev->parent_mixer->fd, MIXER_READ(dev->devno), &v) < 0)
49 return (-1);
50 dev->vol.left = MIX_VOLNORM(v & 0x00ff);
51 dev->vol.right = MIX_VOLNORM((v >> 8) & 0x00ff);
52
53 return (0);
54 }
55
56 /*
57 * Open a mixer device in `/dev/mixerN`, where N is the number of the mixer.
58 * Each device maps to an actual pcm audio card, so `/dev/mixer0` is the
59 * mixer for pcm0, and so on.
60 *
61 * @param name path to mixer device. NULL or "/dev/mixer" for the
62 * the default mixer (i.e `hw.snd.default_unit`).
63 */
64 struct mixer *
mixer_open(const char * name)65 mixer_open(const char *name)
66 {
67 struct mixer *m = NULL;
68 struct mix_dev *dp;
69 const char *names[SOUND_MIXER_NRDEVICES] = SOUND_DEVICE_NAMES;
70 int i;
71
72 if ((m = calloc(1, sizeof(struct mixer))) == NULL)
73 goto fail;
74
75 if (name != NULL) {
76 /* `name` does not start with "/dev/mixer". */
77 if (strncmp(name, BASEPATH, strlen(BASEPATH)) != 0) {
78 m->unit = -1;
79 } else {
80 /* `name` is "/dev/mixer" so, we'll use the default unit. */
81 if (strncmp(name, BASEPATH, strlen(name)) == 0)
82 goto dunit;
83 m->unit = strtol(name + strlen(BASEPATH), NULL, 10);
84 }
85 (void)strlcpy(m->name, name, sizeof(m->name));
86 } else {
87 dunit:
88 if ((m->unit = mixer_get_dunit()) < 0)
89 goto fail;
90 (void)snprintf(m->name, sizeof(m->name), BASEPATH "%d", m->unit);
91 }
92
93 if ((m->fd = open(m->name, O_RDWR)) < 0)
94 goto fail;
95
96 m->devmask = m->recmask = m->recsrc = 0;
97 m->f_default = m->unit == mixer_get_dunit();
98 m->mode = mixer_get_mode(m->unit);
99 /* The unit number _must_ be set before the ioctl. */
100 m->mi.dev = m->unit;
101 m->ci.card = m->unit;
102 if (ioctl(m->fd, SNDCTL_MIXERINFO, &m->mi) < 0) {
103 memset(&m->mi, 0, sizeof(m->mi));
104 strlcpy(m->mi.name, m->name, sizeof(m->mi.name));
105 }
106 if (ioctl(m->fd, SNDCTL_CARDINFO, &m->ci) < 0)
107 memset(&m->ci, 0, sizeof(m->ci));
108 if (ioctl(m->fd, SOUND_MIXER_READ_DEVMASK, &m->devmask) < 0 ||
109 ioctl(m->fd, SOUND_MIXER_READ_MUTE, &m->mutemask) < 0 ||
110 ioctl(m->fd, SOUND_MIXER_READ_RECMASK, &m->recmask) < 0 ||
111 ioctl(m->fd, SOUND_MIXER_READ_RECSRC, &m->recsrc) < 0)
112 goto fail;
113
114 TAILQ_INIT(&m->devs);
115 for (i = 0; i < SOUND_MIXER_NRDEVICES; i++) {
116 if (!MIX_ISDEV(m, i))
117 continue;
118 if ((dp = calloc(1, sizeof(struct mix_dev))) == NULL)
119 goto fail;
120 dp->parent_mixer = m;
121 dp->devno = i;
122 dp->nctl = 0;
123 if (_mixer_readvol(dp) < 0)
124 goto fail;
125 (void)strlcpy(dp->name, names[i], sizeof(dp->name));
126 TAILQ_INIT(&dp->ctls);
127 TAILQ_INSERT_TAIL(&m->devs, dp, devs);
128 m->ndev++;
129 }
130
131 /* The default device is always "vol". */
132 m->dev = TAILQ_FIRST(&m->devs);
133
134 return (m);
135 fail:
136 if (m != NULL)
137 (void)mixer_close(m);
138
139 return (NULL);
140 }
141
142 /*
143 * Free resources and close the mixer.
144 */
145 int
mixer_close(struct mixer * m)146 mixer_close(struct mixer *m)
147 {
148 struct mix_dev *dp;
149 int r;
150
151 r = close(m->fd);
152 while (!TAILQ_EMPTY(&m->devs)) {
153 dp = TAILQ_FIRST(&m->devs);
154 TAILQ_REMOVE(&m->devs, dp, devs);
155 while (!TAILQ_EMPTY(&dp->ctls))
156 (void)mixer_remove_ctl(TAILQ_FIRST(&dp->ctls));
157 free(dp);
158 }
159 free(m);
160
161 return (r);
162 }
163
164 /*
165 * Select a mixer device. The mixer structure keeps a list of all the devices
166 * the mixer has, but only one can be manipulated at a time -- this is what
167 * the `dev` in the mixer structure field is for. Each time a device is to be
168 * manipulated, `dev` has to point to it first.
169 *
170 * The caller must manually assign the return value to `m->dev`.
171 */
172 struct mix_dev *
mixer_get_dev(struct mixer * m,int dev)173 mixer_get_dev(struct mixer *m, int dev)
174 {
175 struct mix_dev *dp;
176
177 if (dev < 0 || dev >= m->ndev) {
178 errno = ERANGE;
179 return (NULL);
180 }
181 TAILQ_FOREACH(dp, &m->devs, devs) {
182 if (dp->devno == dev)
183 return (dp);
184 }
185 errno = EINVAL;
186
187 return (NULL);
188 }
189
190 /*
191 * Select a device by name.
192 *
193 * @param name device name (e.g vol, pcm, ...)
194 */
195 struct mix_dev *
mixer_get_dev_byname(struct mixer * m,const char * name)196 mixer_get_dev_byname(struct mixer *m, const char *name)
197 {
198 struct mix_dev *dp;
199
200 TAILQ_FOREACH(dp, &m->devs, devs) {
201 if (!strncmp(dp->name, name, sizeof(dp->name)))
202 return (dp);
203 }
204 errno = EINVAL;
205
206 return (NULL);
207 }
208
209 /*
210 * Add a mixer control to a device.
211 */
212 int
mixer_add_ctl(struct mix_dev * parent_dev,int id,const char * name,int (* mod)(struct mix_dev *,void *),int (* print)(struct mix_dev *,void *))213 mixer_add_ctl(struct mix_dev *parent_dev, int id, const char *name,
214 int (*mod)(struct mix_dev *, void *),
215 int (*print)(struct mix_dev *, void *))
216 {
217 struct mix_dev *dp;
218 mix_ctl_t *ctl, *cp;
219
220 /* XXX: should we accept NULL name? */
221 if (parent_dev == NULL) {
222 errno = EINVAL;
223 return (-1);
224 }
225 if ((ctl = calloc(1, sizeof(mix_ctl_t))) == NULL)
226 return (-1);
227 ctl->parent_dev = parent_dev;
228 ctl->id = id;
229 if (name != NULL)
230 (void)strlcpy(ctl->name, name, sizeof(ctl->name));
231 ctl->mod = mod;
232 ctl->print = print;
233 dp = ctl->parent_dev;
234 /* Make sure the same ID or name doesn't exist already. */
235 TAILQ_FOREACH(cp, &dp->ctls, ctls) {
236 if (!strncmp(cp->name, name, sizeof(cp->name)) || cp->id == id) {
237 errno = EINVAL;
238 return (-1);
239 }
240 }
241 TAILQ_INSERT_TAIL(&dp->ctls, ctl, ctls);
242 dp->nctl++;
243
244 return (0);
245 }
246
247 /*
248 * Same as `mixer_add_ctl`.
249 */
250 int
mixer_add_ctl_s(mix_ctl_t * ctl)251 mixer_add_ctl_s(mix_ctl_t *ctl)
252 {
253 if (ctl == NULL)
254 return (-1);
255
256 return (mixer_add_ctl(ctl->parent_dev, ctl->id, ctl->name,
257 ctl->mod, ctl->print));
258 }
259
260 /*
261 * Remove a mixer control from a device.
262 */
263 int
mixer_remove_ctl(mix_ctl_t * ctl)264 mixer_remove_ctl(mix_ctl_t *ctl)
265 {
266 struct mix_dev *p;
267
268 if (ctl == NULL) {
269 errno = EINVAL;
270 return (-1);
271 }
272 p = ctl->parent_dev;
273 if (!TAILQ_EMPTY(&p->ctls)) {
274 TAILQ_REMOVE(&p->ctls, ctl, ctls);
275 free(ctl);
276 }
277
278 return (0);
279 }
280
281 /*
282 * Get a mixer control by id.
283 */
284 mix_ctl_t *
mixer_get_ctl(struct mix_dev * d,int id)285 mixer_get_ctl(struct mix_dev *d, int id)
286 {
287 mix_ctl_t *cp;
288
289 TAILQ_FOREACH(cp, &d->ctls, ctls) {
290 if (cp->id == id)
291 return (cp);
292 }
293 errno = EINVAL;
294
295 return (NULL);
296 }
297
298 /*
299 * Get a mixer control by name.
300 */
301 mix_ctl_t *
mixer_get_ctl_byname(struct mix_dev * d,const char * name)302 mixer_get_ctl_byname(struct mix_dev *d, const char *name)
303 {
304 mix_ctl_t *cp;
305
306 TAILQ_FOREACH(cp, &d->ctls, ctls) {
307 if (!strncmp(cp->name, name, sizeof(cp->name)))
308 return (cp);
309 }
310 errno = EINVAL;
311
312 return (NULL);
313 }
314
315 /*
316 * Change the mixer's left and right volume. The allowed volume values are
317 * between MIX_VOLMIN and MIX_VOLMAX. The `ioctl` for volume change requires
318 * an integer value between 0 and 100 stored as `lvol | rvol << 8` -- for
319 * that reason, we de-normalize the 32-bit float volume value, before
320 * we pass it to the `ioctl`.
321 *
322 * Volume clumping should be done by the caller.
323 */
324 int
mixer_set_vol(struct mixer * m,mix_volume_t vol)325 mixer_set_vol(struct mixer *m, mix_volume_t vol)
326 {
327 int v;
328
329 if (vol.left < MIX_VOLMIN || vol.left > MIX_VOLMAX ||
330 vol.right < MIX_VOLMIN || vol.right > MIX_VOLMAX) {
331 errno = ERANGE;
332 return (-1);
333 }
334 v = MIX_VOLDENORM(vol.left) | MIX_VOLDENORM(vol.right) << 8;
335 if (ioctl(m->fd, MIXER_WRITE(m->dev->devno), &v) < 0)
336 return (-1);
337 if (_mixer_readvol(m->dev) < 0)
338 return (-1);
339
340 return (0);
341 }
342
343 /*
344 * Manipulate a device's mute.
345 *
346 * @param opt MIX_MUTE mute device
347 * MIX_UNMUTE unmute device
348 * MIX_TOGGLEMUTE toggle device's mute
349 */
350 int
mixer_set_mute(struct mixer * m,int opt)351 mixer_set_mute(struct mixer *m, int opt)
352 {
353 switch (opt) {
354 case MIX_MUTE:
355 m->mutemask |= (1 << m->dev->devno);
356 break;
357 case MIX_UNMUTE:
358 m->mutemask &= ~(1 << m->dev->devno);
359 break;
360 case MIX_TOGGLEMUTE:
361 m->mutemask ^= (1 << m->dev->devno);
362 break;
363 default:
364 errno = EINVAL;
365 return (-1);
366 }
367 if (ioctl(m->fd, SOUND_MIXER_WRITE_MUTE, &m->mutemask) < 0)
368 return (-1);
369 if (ioctl(m->fd, SOUND_MIXER_READ_MUTE, &m->mutemask) < 0)
370 return (-1);
371
372 return 0;
373 }
374
375 /*
376 * Modify a recording device. The selected device has to be a recording device,
377 * otherwise the function will fail.
378 *
379 * @param opt MIX_ADDRECSRC add device to recording sources
380 * MIX_REMOVERECSRC remove device from recording sources
381 * MIX_SETRECSRC set device as the only recording source
382 * MIX_TOGGLERECSRC toggle device from recording sources
383 */
384 int
mixer_mod_recsrc(struct mixer * m,int opt)385 mixer_mod_recsrc(struct mixer *m, int opt)
386 {
387 if (!m->recmask || !MIX_ISREC(m, m->dev->devno)) {
388 errno = ENODEV;
389 return (-1);
390 }
391 switch (opt) {
392 case MIX_ADDRECSRC:
393 m->recsrc |= (1 << m->dev->devno);
394 break;
395 case MIX_REMOVERECSRC:
396 m->recsrc &= ~(1 << m->dev->devno);
397 break;
398 case MIX_SETRECSRC:
399 m->recsrc = (1 << m->dev->devno);
400 break;
401 case MIX_TOGGLERECSRC:
402 m->recsrc ^= (1 << m->dev->devno);
403 break;
404 default:
405 errno = EINVAL;
406 return (-1);
407 }
408 if (ioctl(m->fd, SOUND_MIXER_WRITE_RECSRC, &m->recsrc) < 0)
409 return (-1);
410 if (ioctl(m->fd, SOUND_MIXER_READ_RECSRC, &m->recsrc) < 0)
411 return (-1);
412
413 return (0);
414 }
415
416 /*
417 * Get default audio card's number. This is used to open the default mixer
418 * and set the mixer structure's `f_default` flag.
419 */
420 int
mixer_get_dunit(void)421 mixer_get_dunit(void)
422 {
423 size_t size;
424 int unit;
425
426 size = sizeof(int);
427 if (sysctlbyname("hw.snd.default_unit", &unit, &size, NULL, 0) < 0)
428 return (-1);
429
430 return (unit);
431 }
432
433 /*
434 * Change the default audio card. This is normally _not_ a mixer feature, but
435 * it's useful to have, so the caller can avoid having to manually use
436 * the sysctl API.
437 *
438 * @param unit the audio card number (e.g pcm0, pcm1, ...).
439 */
440 int
mixer_set_dunit(struct mixer * m,int unit)441 mixer_set_dunit(struct mixer *m, int unit)
442 {
443 size_t size;
444
445 size = sizeof(int);
446 if (sysctlbyname("hw.snd.default_unit", NULL, 0, &unit, size) < 0)
447 return (-1);
448 /* XXX: how will other mixers get updated? */
449 m->f_default = m->unit == unit;
450
451 return (0);
452 }
453
454 /*
455 * Get sound device mode (none, play, rec, play+rec). Userland programs can
456 * use the MIX_MODE_* flags to determine the mode of the device.
457 */
458 int
mixer_get_mode(int unit)459 mixer_get_mode(int unit)
460 {
461 char buf[64];
462 size_t size;
463 unsigned int mode;
464
465 (void)snprintf(buf, sizeof(buf), "dev.pcm.%d.mode", unit);
466 size = sizeof(unsigned int);
467 if (sysctlbyname(buf, &mode, &size, NULL, 0) < 0)
468 return (0);
469
470 return (mode);
471 }
472
473 /*
474 * Get the total number of mixers in the system.
475 */
476 int
mixer_get_nmixers(void)477 mixer_get_nmixers(void)
478 {
479 struct mixer *m;
480 oss_sysinfo si;
481
482 /*
483 * Open a dummy mixer because we need the `fd` field for the
484 * `ioctl` to work.
485 */
486 if ((m = mixer_open(NULL)) == NULL)
487 return (-1);
488 if (ioctl(m->fd, OSS_SYSINFO, &si) < 0) {
489 (void)mixer_close(m);
490 return (-1);
491 }
492 (void)mixer_close(m);
493
494 return (si.nummixers);
495 }
496
497 /*
498 * Get the full path to a mixer device.
499 */
500 int
mixer_get_path(char * buf,size_t size,int unit)501 mixer_get_path(char *buf, size_t size, int unit)
502 {
503 size_t n;
504
505 if (!(unit == -1 || (unit >= 0 && unit < mixer_get_nmixers()))) {
506 errno = EINVAL;
507 return (-1);
508 }
509 if (unit == -1)
510 n = strlcpy(buf, BASEPATH, size);
511 else
512 n = snprintf(buf, size, BASEPATH "%d", unit);
513
514 if (n >= size) {
515 errno = ENOMEM;
516 return (-1);
517 }
518
519 return (0);
520 }
521