xref: /openbmc/linux/sound/core/vmaster.c (revision 95e9fd10)
1 /*
2  * Virtual master and slave controls
3  *
4  *  Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
5  *
6  *  This program is free software; you can redistribute it and/or
7  *  modify it under the terms of the GNU General Public License as
8  *  published by the Free Software Foundation, version 2.
9  *
10  */
11 
12 #include <linux/slab.h>
13 #include <linux/export.h>
14 #include <sound/core.h>
15 #include <sound/control.h>
16 #include <sound/tlv.h>
17 
18 /*
19  * a subset of information returned via ctl info callback
20  */
21 struct link_ctl_info {
22 	snd_ctl_elem_type_t type; /* value type */
23 	int count;		/* item count */
24 	int min_val, max_val;	/* min, max values */
25 };
26 
27 /*
28  * link master - this contains a list of slave controls that are
29  * identical types, i.e. info returns the same value type and value
30  * ranges, but may have different number of counts.
31  *
32  * The master control is so far only mono volume/switch for simplicity.
33  * The same value will be applied to all slaves.
34  */
35 struct link_master {
36 	struct list_head slaves;
37 	struct link_ctl_info info;
38 	int val;		/* the master value */
39 	unsigned int tlv[4];
40 	void (*hook)(void *private_data, int);
41 	void *hook_private_data;
42 };
43 
44 /*
45  * link slave - this contains a slave control element
46  *
47  * It fakes the control callbacsk with additional attenuation by the
48  * master control.  A slave may have either one or two channels.
49  */
50 
51 struct link_slave {
52 	struct list_head list;
53 	struct link_master *master;
54 	struct link_ctl_info info;
55 	int vals[2];		/* current values */
56 	unsigned int flags;
57 	struct snd_kcontrol *kctl; /* original kcontrol pointer */
58 	struct snd_kcontrol slave; /* the copy of original control entry */
59 };
60 
61 static int slave_update(struct link_slave *slave)
62 {
63 	struct snd_ctl_elem_value *uctl;
64 	int err, ch;
65 
66 	uctl = kmalloc(sizeof(*uctl), GFP_KERNEL);
67 	if (!uctl)
68 		return -ENOMEM;
69 	uctl->id = slave->slave.id;
70 	err = slave->slave.get(&slave->slave, uctl);
71 	for (ch = 0; ch < slave->info.count; ch++)
72 		slave->vals[ch] = uctl->value.integer.value[ch];
73 	kfree(uctl);
74 	return 0;
75 }
76 
77 /* get the slave ctl info and save the initial values */
78 static int slave_init(struct link_slave *slave)
79 {
80 	struct snd_ctl_elem_info *uinfo;
81 	int err;
82 
83 	if (slave->info.count) {
84 		/* already initialized */
85 		if (slave->flags & SND_CTL_SLAVE_NEED_UPDATE)
86 			return slave_update(slave);
87 		return 0;
88 	}
89 
90 	uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
91 	if (!uinfo)
92 		return -ENOMEM;
93 	uinfo->id = slave->slave.id;
94 	err = slave->slave.info(&slave->slave, uinfo);
95 	if (err < 0) {
96 		kfree(uinfo);
97 		return err;
98 	}
99 	slave->info.type = uinfo->type;
100 	slave->info.count = uinfo->count;
101 	if (slave->info.count > 2  ||
102 	    (slave->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
103 	     slave->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
104 		snd_printk(KERN_ERR "invalid slave element\n");
105 		kfree(uinfo);
106 		return -EINVAL;
107 	}
108 	slave->info.min_val = uinfo->value.integer.min;
109 	slave->info.max_val = uinfo->value.integer.max;
110 	kfree(uinfo);
111 
112 	return slave_update(slave);
113 }
114 
115 /* initialize master volume */
116 static int master_init(struct link_master *master)
117 {
118 	struct link_slave *slave;
119 
120 	if (master->info.count)
121 		return 0; /* already initialized */
122 
123 	list_for_each_entry(slave, &master->slaves, list) {
124 		int err = slave_init(slave);
125 		if (err < 0)
126 			return err;
127 		master->info = slave->info;
128 		master->info.count = 1; /* always mono */
129 		/* set full volume as default (= no attenuation) */
130 		master->val = master->info.max_val;
131 		if (master->hook)
132 			master->hook(master->hook_private_data, master->val);
133 		return 1;
134 	}
135 	return -ENOENT;
136 }
137 
138 static int slave_get_val(struct link_slave *slave,
139 			 struct snd_ctl_elem_value *ucontrol)
140 {
141 	int err, ch;
142 
143 	err = slave_init(slave);
144 	if (err < 0)
145 		return err;
146 	for (ch = 0; ch < slave->info.count; ch++)
147 		ucontrol->value.integer.value[ch] = slave->vals[ch];
148 	return 0;
149 }
150 
151 static int slave_put_val(struct link_slave *slave,
152 			 struct snd_ctl_elem_value *ucontrol)
153 {
154 	int err, ch, vol;
155 
156 	err = master_init(slave->master);
157 	if (err < 0)
158 		return err;
159 
160 	switch (slave->info.type) {
161 	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
162 		for (ch = 0; ch < slave->info.count; ch++)
163 			ucontrol->value.integer.value[ch] &=
164 				!!slave->master->val;
165 		break;
166 	case SNDRV_CTL_ELEM_TYPE_INTEGER:
167 		for (ch = 0; ch < slave->info.count; ch++) {
168 			/* max master volume is supposed to be 0 dB */
169 			vol = ucontrol->value.integer.value[ch];
170 			vol += slave->master->val - slave->master->info.max_val;
171 			if (vol < slave->info.min_val)
172 				vol = slave->info.min_val;
173 			else if (vol > slave->info.max_val)
174 				vol = slave->info.max_val;
175 			ucontrol->value.integer.value[ch] = vol;
176 		}
177 		break;
178 	}
179 	return slave->slave.put(&slave->slave, ucontrol);
180 }
181 
182 /*
183  * ctl callbacks for slaves
184  */
185 static int slave_info(struct snd_kcontrol *kcontrol,
186 		      struct snd_ctl_elem_info *uinfo)
187 {
188 	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
189 	return slave->slave.info(&slave->slave, uinfo);
190 }
191 
192 static int slave_get(struct snd_kcontrol *kcontrol,
193 		     struct snd_ctl_elem_value *ucontrol)
194 {
195 	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
196 	return slave_get_val(slave, ucontrol);
197 }
198 
199 static int slave_put(struct snd_kcontrol *kcontrol,
200 		     struct snd_ctl_elem_value *ucontrol)
201 {
202 	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
203 	int err, ch, changed = 0;
204 
205 	err = slave_init(slave);
206 	if (err < 0)
207 		return err;
208 	for (ch = 0; ch < slave->info.count; ch++) {
209 		if (slave->vals[ch] != ucontrol->value.integer.value[ch]) {
210 			changed = 1;
211 			slave->vals[ch] = ucontrol->value.integer.value[ch];
212 		}
213 	}
214 	if (!changed)
215 		return 0;
216 	return slave_put_val(slave, ucontrol);
217 }
218 
219 static int slave_tlv_cmd(struct snd_kcontrol *kcontrol,
220 			 int op_flag, unsigned int size,
221 			 unsigned int __user *tlv)
222 {
223 	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
224 	/* FIXME: this assumes that the max volume is 0 dB */
225 	return slave->slave.tlv.c(&slave->slave, op_flag, size, tlv);
226 }
227 
228 static void slave_free(struct snd_kcontrol *kcontrol)
229 {
230 	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
231 	if (slave->slave.private_free)
232 		slave->slave.private_free(&slave->slave);
233 	if (slave->master)
234 		list_del(&slave->list);
235 	kfree(slave);
236 }
237 
238 /*
239  * Add a slave control to the group with the given master control
240  *
241  * All slaves must be the same type (returning the same information
242  * via info callback).  The function doesn't check it, so it's your
243  * responsibility.
244  *
245  * Also, some additional limitations:
246  * - at most two channels
247  * - logarithmic volume control (dB level), no linear volume
248  * - master can only attenuate the volume, no gain
249  */
250 int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
251 		       unsigned int flags)
252 {
253 	struct link_master *master_link = snd_kcontrol_chip(master);
254 	struct link_slave *srec;
255 
256 	srec = kzalloc(sizeof(*srec) +
257 		       slave->count * sizeof(*slave->vd), GFP_KERNEL);
258 	if (!srec)
259 		return -ENOMEM;
260 	srec->kctl = slave;
261 	srec->slave = *slave;
262 	memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
263 	srec->master = master_link;
264 	srec->flags = flags;
265 
266 	/* override callbacks */
267 	slave->info = slave_info;
268 	slave->get = slave_get;
269 	slave->put = slave_put;
270 	if (slave->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
271 		slave->tlv.c = slave_tlv_cmd;
272 	slave->private_data = srec;
273 	slave->private_free = slave_free;
274 
275 	list_add_tail(&srec->list, &master_link->slaves);
276 	return 0;
277 }
278 EXPORT_SYMBOL(_snd_ctl_add_slave);
279 
280 /*
281  * ctl callbacks for master controls
282  */
283 static int master_info(struct snd_kcontrol *kcontrol,
284 		      struct snd_ctl_elem_info *uinfo)
285 {
286 	struct link_master *master = snd_kcontrol_chip(kcontrol);
287 	int ret;
288 
289 	ret = master_init(master);
290 	if (ret < 0)
291 		return ret;
292 	uinfo->type = master->info.type;
293 	uinfo->count = master->info.count;
294 	uinfo->value.integer.min = master->info.min_val;
295 	uinfo->value.integer.max = master->info.max_val;
296 	return 0;
297 }
298 
299 static int master_get(struct snd_kcontrol *kcontrol,
300 		      struct snd_ctl_elem_value *ucontrol)
301 {
302 	struct link_master *master = snd_kcontrol_chip(kcontrol);
303 	int err = master_init(master);
304 	if (err < 0)
305 		return err;
306 	ucontrol->value.integer.value[0] = master->val;
307 	return 0;
308 }
309 
310 static int master_put(struct snd_kcontrol *kcontrol,
311 		      struct snd_ctl_elem_value *ucontrol)
312 {
313 	struct link_master *master = snd_kcontrol_chip(kcontrol);
314 	struct link_slave *slave;
315 	struct snd_ctl_elem_value *uval;
316 	int err, old_val;
317 
318 	err = master_init(master);
319 	if (err < 0)
320 		return err;
321 	old_val = master->val;
322 	if (ucontrol->value.integer.value[0] == old_val)
323 		return 0;
324 
325 	uval = kmalloc(sizeof(*uval), GFP_KERNEL);
326 	if (!uval)
327 		return -ENOMEM;
328 	list_for_each_entry(slave, &master->slaves, list) {
329 		master->val = old_val;
330 		uval->id = slave->slave.id;
331 		slave_get_val(slave, uval);
332 		master->val = ucontrol->value.integer.value[0];
333 		slave_put_val(slave, uval);
334 	}
335 	kfree(uval);
336 	if (master->hook && !err)
337 		master->hook(master->hook_private_data, master->val);
338 	return 1;
339 }
340 
341 static void master_free(struct snd_kcontrol *kcontrol)
342 {
343 	struct link_master *master = snd_kcontrol_chip(kcontrol);
344 	struct link_slave *slave, *n;
345 
346 	/* free all slave links and retore the original slave kctls */
347 	list_for_each_entry_safe(slave, n, &master->slaves, list) {
348 		struct snd_kcontrol *sctl = slave->kctl;
349 		struct list_head olist = sctl->list;
350 		memcpy(sctl, &slave->slave, sizeof(*sctl));
351 		memcpy(sctl->vd, slave->slave.vd,
352 		       sctl->count * sizeof(*sctl->vd));
353 		sctl->list = olist; /* keep the current linked-list */
354 		kfree(slave);
355 	}
356 	kfree(master);
357 }
358 
359 
360 /**
361  * snd_ctl_make_virtual_master - Create a virtual master control
362  * @name: name string of the control element to create
363  * @tlv: optional TLV int array for dB information
364  *
365  * Creates a virtual matster control with the given name string.
366  * Returns the created control element, or NULL for errors (ENOMEM).
367  *
368  * After creating a vmaster element, you can add the slave controls
369  * via snd_ctl_add_slave() or snd_ctl_add_slave_uncached().
370  *
371  * The optional argument @tlv can be used to specify the TLV information
372  * for dB scale of the master control.  It should be a single element
373  * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
374  * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
375  */
376 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
377 						 const unsigned int *tlv)
378 {
379 	struct link_master *master;
380 	struct snd_kcontrol *kctl;
381 	struct snd_kcontrol_new knew;
382 
383 	memset(&knew, 0, sizeof(knew));
384 	knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
385 	knew.name = name;
386 	knew.info = master_info;
387 
388 	master = kzalloc(sizeof(*master), GFP_KERNEL);
389 	if (!master)
390 		return NULL;
391 	INIT_LIST_HEAD(&master->slaves);
392 
393 	kctl = snd_ctl_new1(&knew, master);
394 	if (!kctl) {
395 		kfree(master);
396 		return NULL;
397 	}
398 	/* override some callbacks */
399 	kctl->info = master_info;
400 	kctl->get = master_get;
401 	kctl->put = master_put;
402 	kctl->private_free = master_free;
403 
404 	/* additional (constant) TLV read */
405 	if (tlv &&
406 	    (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
407 	     tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
408 	     tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
409 		kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
410 		memcpy(master->tlv, tlv, sizeof(master->tlv));
411 		kctl->tlv.p = master->tlv;
412 	}
413 
414 	return kctl;
415 }
416 EXPORT_SYMBOL(snd_ctl_make_virtual_master);
417 
418 /**
419  * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
420  * @kcontrol: vmaster kctl element
421  * @hook: the hook function
422  * @private_data: the private_data pointer to be saved
423  *
424  * Adds the given hook to the vmaster control element so that it's called
425  * at each time when the value is changed.
426  */
427 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
428 			     void (*hook)(void *private_data, int),
429 			     void *private_data)
430 {
431 	struct link_master *master = snd_kcontrol_chip(kcontrol);
432 	master->hook = hook;
433 	master->hook_private_data = private_data;
434 	return 0;
435 }
436 EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);
437 
438 /**
439  * snd_ctl_sync_vmaster_hook - Sync the vmaster hook
440  * @kcontrol: vmaster kctl element
441  *
442  * Call the hook function to synchronize with the current value of the given
443  * vmaster element.  NOP when NULL is passed to @kcontrol or the hook doesn't
444  * exist.
445  */
446 void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kcontrol)
447 {
448 	struct link_master *master;
449 	if (!kcontrol)
450 		return;
451 	master = snd_kcontrol_chip(kcontrol);
452 	if (master->hook)
453 		master->hook(master->hook_private_data, master->val);
454 }
455 EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster_hook);
456