summaryrefslogtreecommitdiff
path: root/sound/core/vmaster.c
blob: a39d3d8c2f9c9edb53025953c102f5d5cdb89aa3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
/*
 * Virtual master and slave controls
 *
 *  Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2.
 *
 */

#include <linux/slab.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/tlv.h>

/*
 * a subset of information returned via ctl info callback
 */
struct link_ctl_info {
	snd_ctl_elem_type_t type; /* value type */
	int count;		/* item count */
	int min_val, max_val;	/* min, max values */
};

/*
 * link master - this contains a list of slave controls that are
 * identical types, i.e. info returns the same value type and value
 * ranges, but may have different number of counts.
 *
 * The master control is so far only mono volume/switch for simplicity.
 * The same value will be applied to all slaves.
 */
struct link_master {
	struct list_head slaves;
	struct link_ctl_info info;
	int val;		/* the master value */
	unsigned int tlv[4];
};

/*
 * link slave - this contains a slave control element
 *
 * It fakes the control callbacsk with additional attenuation by the
 * master control.  A slave may have either one or two channels.
 */

struct link_slave {
	struct list_head list;
	struct link_master *master;
	struct link_ctl_info info;
	int vals[2];		/* current values */
	unsigned int flags;
	struct snd_kcontrol slave; /* the copy of original control entry */
};

static int slave_update(struct link_slave *slave)
{
	struct snd_ctl_elem_value *uctl;
	int err, ch;

	uctl = kmalloc(sizeof(*uctl), GFP_KERNEL);
	if (!uctl)
		return -ENOMEM;
	uctl->id = slave->slave.id;
	err = slave->slave.get(&slave->slave, uctl);
	for (ch = 0; ch < slave->info.count; ch++)
		slave->vals[ch] = uctl->value.integer.value[ch];
	kfree(uctl);
	return 0;
}

/* get the slave ctl info and save the initial values */
static int slave_init(struct link_slave *slave)
{
	struct snd_ctl_elem_info *uinfo;
	int err;

	if (slave->info.count) {
		/* already initialized */
		if (slave->flags & SND_CTL_SLAVE_NEED_UPDATE)
			return slave_update(slave);
		return 0;
	}

	uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
	if (!uinfo)
		return -ENOMEM;
	uinfo->id = slave->slave.id;
	err = slave->slave.info(&slave->slave, uinfo);
	if (err < 0) {
		kfree(uinfo);
		return err;
	}
	slave->info.type = uinfo->type;
	slave->info.count = uinfo->count;
	if (slave->info.count > 2  ||
	    (slave->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
	     slave->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
		snd_printk(KERN_ERR "invalid slave element\n");
		kfree(uinfo);
		return -EINVAL;
	}
	slave->info.min_val = uinfo->value.integer.min;
	slave->info.max_val = uinfo->value.integer.max;
	kfree(uinfo);

	return slave_update(slave);
}

/* initialize master volume */
static int master_init(struct link_master *master)
{
	struct link_slave *slave;

	if (master->info.count)
		return 0; /* already initialized */

	list_for_each_entry(slave, &master->slaves, list) {
		int err = slave_init(slave);
		if (err < 0)
			return err;
		master->info = slave->info;
		master->info.count = 1; /* always mono */
		/* set full volume as default (= no attenuation) */
		master->val = master->info.max_val;
		return 0;
	}
	return -ENOENT;
}

static int slave_get_val(struct link_slave *slave,
			 struct snd_ctl_elem_value *ucontrol)
{
	int err, ch;

	err = slave_init(slave);
	if (err < 0)
		return err;
	for (ch = 0; ch < slave->info.count; ch++)
		ucontrol->value.integer.value[ch] = slave->vals[ch];
	return 0;
}

static int slave_put_val(struct link_slave *slave,
			 struct snd_ctl_elem_value *ucontrol)
{
	int err, ch, vol;

	err = master_init(slave->master);
	if (err < 0)
		return err;

	switch (slave->info.type) {
	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
		for (ch = 0; ch < slave->info.count; ch++)
			ucontrol->value.integer.value[ch] &=
				!!slave->master->val;
		break;
	case SNDRV_CTL_ELEM_TYPE_INTEGER:
		for (ch = 0; ch < slave->info.count; ch++) {
			/* max master volume is supposed to be 0 dB */
			vol = ucontrol->value.integer.value[ch];
			vol += slave->master->val - slave->master->info.max_val;
			if (vol < slave->info.min_val)
				vol = slave->info.min_val;
			else if (vol > slave->info.max_val)
				vol = slave->info.max_val;
			ucontrol->value.integer.value[ch] = vol;
		}
		break;
	}
	return slave->slave.put(&slave->slave, ucontrol);
}

/*
 * ctl callbacks for slaves
 */
static int slave_info(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_info *uinfo)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	return slave->slave.info(&slave->slave, uinfo);
}

static int slave_get(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	return slave_get_val(slave, ucontrol);
}

static int slave_put(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	int err, ch, changed = 0;

	err = slave_init(slave);
	if (err < 0)
		return err;
	for (ch = 0; ch < slave->info.count; ch++) {
		if (slave->vals[ch] != ucontrol->value.integer.value[ch]) {
			changed = 1;
			slave->vals[ch] = ucontrol->value.integer.value[ch];
		}
	}
	if (!changed)
		return 0;
	return slave_put_val(slave, ucontrol);
}

static int slave_tlv_cmd(struct snd_kcontrol *kcontrol,
			 int op_flag, unsigned int size,
			 unsigned int __user *tlv)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	/* FIXME: this assumes that the max volume is 0 dB */
	return slave->slave.tlv.c(&slave->slave, op_flag, size, tlv);
}

static void slave_free(struct snd_kcontrol *kcontrol)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	if (slave->slave.private_free)
		slave->slave.private_free(&slave->slave);
	if (slave->master)
		list_del(&slave->list);
	kfree(slave);
}

/*
 * Add a slave control to the group with the given master control
 *
 * All slaves must be the same type (returning the same information
 * via info callback).  The function doesn't check it, so it's your
 * responsibility.
 *
 * Also, some additional limitations:
 * - at most two channels
 * - logarithmic volume control (dB level), no linear volume
 * - master can only attenuate the volume, no gain
 */
int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
		       unsigned int flags)
{
	struct link_master *master_link = snd_kcontrol_chip(master);
	struct link_slave *srec;

	srec = kzalloc(sizeof(*srec) +
		       slave->count * sizeof(*slave->vd), GFP_KERNEL);
	if (!srec)
		return -ENOMEM;
	srec->slave = *slave;
	memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
	srec->master = master_link;
	srec->flags = flags;

	/* override callbacks */
	slave->info = slave_info;
	slave->get = slave_get;
	slave->put = slave_put;
	if (slave->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
		slave->tlv.c = slave_tlv_cmd;
	slave->private_data = srec;
	slave->private_free = slave_free;

	list_add_tail(&srec->list, &master_link->slaves);
	return 0;
}
EXPORT_SYMBOL(_snd_ctl_add_slave);

/*
 * ctl callbacks for master controls
 */
static int master_info(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_info *uinfo)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	int ret;

	ret = master_init(master);
	if (ret < 0)
		return ret;
	uinfo->type = master->info.type;
	uinfo->count = master->info.count;
	uinfo->value.integer.min = master->info.min_val;
	uinfo->value.integer.max = master->info.max_val;
	return 0;
}

static int master_get(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_value *ucontrol)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	int err = master_init(master);
	if (err < 0)
		return err;
	ucontrol->value.integer.value[0] = master->val;
	return 0;
}

static int master_put(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_value *ucontrol)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	struct link_slave *slave;
	struct snd_ctl_elem_value *uval;
	int err, old_val;

	err = master_init(master);
	if (err < 0)
		return err;
	old_val = master->val;
	if (ucontrol->value.integer.value[0] == old_val)
		return 0;

	uval = kmalloc(sizeof(*uval), GFP_KERNEL);
	if (!uval)
		return -ENOMEM;
	list_for_each_entry(slave, &master->slaves, list) {
		master->val = old_val;
		uval->id = slave->slave.id;
		slave_get_val(slave, uval);
		master->val = ucontrol->value.integer.value[0];
		slave_put_val(slave, uval);
	}
	kfree(uval);
	return 1;
}

static void master_free(struct snd_kcontrol *kcontrol)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	struct link_slave *slave;

	list_for_each_entry(slave, &master->slaves, list)
		slave->master = NULL;
	kfree(master);
}


/**
 * snd_ctl_make_virtual_master - Create a virtual master control
 * @name: name string of the control element to create
 * @tlv: optional TLV int array for dB information
 *
 * Creates a virtual matster control with the given name string.
 * Returns the created control element, or NULL for errors (ENOMEM).
 *
 * After creating a vmaster element, you can add the slave controls
 * via snd_ctl_add_slave() or snd_ctl_add_slave_uncached().
 *
 * The optional argument @tlv can be used to specify the TLV information
 * for dB scale of the master control.  It should be a single element
 * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
 * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
 */
struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
						 const unsigned int *tlv)
{
	struct link_master *master;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_new knew;

	memset(&knew, 0, sizeof(knew));
	knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
	knew.name = name;
	knew.info = master_info;

	master = kzalloc(sizeof(*master), GFP_KERNEL);
	if (!master)
		return NULL;
	INIT_LIST_HEAD(&master->slaves);

	kctl = snd_ctl_new1(&knew, master);
	if (!kctl) {
		kfree(master);
		return NULL;
	}
	/* override some callbacks */
	kctl->info = master_info;
	kctl->get = master_get;
	kctl->put = master_put;
	kctl->private_free = master_free;

	/* additional (constant) TLV read */
	if (tlv &&
	    (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
	     tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
	     tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
		kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
		memcpy(master->tlv, tlv, sizeof(master->tlv));
		kctl->tlv.p = master->tlv;
	}

	return kctl;
}
EXPORT_SYMBOL(snd_ctl_make_virtual_master);