Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND BSD-3-Clause
 *
 * Copyright 2008 by Marco Trillo. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */
/*-
 * Copyright (c) 2002, 2003 Tsubai Masanari.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * 	NetBSD: tumbler.c,v 1.28 2008/05/16 03:49:54 macallan Exp
 *	Id: tumbler.c,v 1.11 2002/10/31 17:42:13 tsubai Exp 
 */

/*
 *	Apple I2S audio controller.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <machine/dbdma.h>
#include <machine/intr_machdep.h>
#include <machine/resource.h>
#include <machine/bus.h>
#include <machine/pio.h>
#include <sys/rman.h>

#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/ofw/ofw_bus.h>

#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_snd.h"
#endif

#include <dev/sound/pcm/sound.h>

#include "mixer_if.h"

extern kobj_class_t i2s_mixer_class;
extern device_t	i2s_mixer;

struct tumbler_softc
{
	device_t sc_dev;
	uint32_t sc_addr;
};

static int	tumbler_probe(device_t);
static int 	tumbler_attach(device_t);
static int	tumbler_init(struct snd_mixer *m);
static int	tumbler_uninit(struct snd_mixer *m);
static int	tumbler_reinit(struct snd_mixer *m);
static int	tumbler_set(struct snd_mixer *m, unsigned dev, unsigned left,
		    unsigned right);
static u_int32_t	tumbler_setrecsrc(struct snd_mixer *m, u_int32_t src);

static device_method_t tumbler_methods[] = {
	/* Device interface. */
	DEVMETHOD(device_probe,		tumbler_probe),
	DEVMETHOD(device_attach,	tumbler_attach),
	{ 0, 0 }
};

static driver_t tumbler_driver = {
	"tumbler",
	tumbler_methods,
	sizeof(struct tumbler_softc)
};
static devclass_t tumbler_devclass;

DRIVER_MODULE(tumbler, iicbus, tumbler_driver, tumbler_devclass, 0, 0);
MODULE_VERSION(tumbler, 1);
MODULE_DEPEND(tumbler, iicbus, 1, 1, 1);

static kobj_method_t tumbler_mixer_methods[] = {
	KOBJMETHOD(mixer_init, 		tumbler_init),
	KOBJMETHOD(mixer_uninit, 	tumbler_uninit),
	KOBJMETHOD(mixer_reinit, 	tumbler_reinit),
	KOBJMETHOD(mixer_set, 		tumbler_set),
	KOBJMETHOD(mixer_setrecsrc, 	tumbler_setrecsrc),
	KOBJMETHOD_END
};

MIXER_DECLARE(tumbler_mixer);

#define TUMBLER_IICADDR		0x68	/* Tumbler I2C slave address */

/* Tumbler (Texas Instruments TAS3001) registers. */
#define TUMBLER_MCR		0x01	/* Main control register (1byte) */
#define TUMBLER_DRC         	0x02    /* Dynamic Range Compression (2bytes) */
#define TUMBLER_VOLUME		0x04	/* Volume (6bytes) */
#define TUMBLER_TREBLE		0x05	/* Treble control (1byte) */
#define TUMBLER_BASS		0x06	/* Bass control (1byte) */
#define TUMBLER_MIXER1		0x07	/* Mixer1 (3bytes) */
#define TUMBLER_MIXER2		0x08	/* Mixer2 (3bytes) */
#define TUMBLER_LB0		0x0a	/* Left biquad 0 (15bytes) */
#define TUMBLER_LB1		0x0b	/* Left biquad 1 (15bytes) */
#define TUMBLER_LB2		0x0c	/* Left biquad 2 (15bytes) */
#define TUMBLER_LB3		0x0d	/* Left biquad 3 (15bytes) */
#define TUMBLER_LB4		0x0e	/* Left biquad 4 (15bytes) */
#define TUMBLER_LB5		0x0f	/* Left biquad 5 (15bytes) */
#define TUMBLER_RB0		0x13	/* Right biquad 0 (15bytes) */
#define TUMBLER_RB1		0x14	/* Right biquad 1 (15bytes) */
#define TUMBLER_RB2		0x15	/* Right biquad 2 (15bytes) */
#define TUMBLER_RB3		0x16	/* Right biquad 3 (15bytes) */
#define TUMBLER_RB4		0x17	/* Right biquad 4 (15bytes) */
#define TUMBLER_RB5		0x18	/* Right biquad 5 (15bytes) */
#define TUMBLER_MCR_FL	0x80	/* Fast load */
#define TUMBLER_MCR_SC	0x40	/* SCLK frequency */
#define  TUMBLER_MCR_SC_32	0x00	/*  32fs */
#define  TUMBLER_MCR_SC_64	0x40	/*  64fs */
#define TUMBLER_MCR_SM	0x30	/* Output serial port mode */
#define  TUMBLER_MCR_SM_L	0x00	/*  Left justified */
#define  TUMBLER_MCR_SM_R	0x10	/*  Right justified */
#define  TUMBLER_MCR_SM_I2S 0x20	/*  I2S */
#define TUMBLER_MCR_ISM    0x0C    /* Input serial mode */
#define  TUMBLER_MCR_ISM_L 0x00
#define  TUMBLER_MCR_ISM_R 0x04
#define  TUMBLER_MCR_ISM_I2S 0x08
#define TUMBLER_MCR_W	0x03	/* Serial port word length */
#define  TUMBLER_MCR_W_16	0x00	/*  16 bit */
#define  TUMBLER_MCR_W_18	0x01	/*  18 bit */
#define  TUMBLER_MCR_W_20	0x02	/*  20 bit */
#define TUMBLER_DRC_COMP_31 0xc0    /* 3:1 compression */
#define TUMBLER_DRC_ENABLE  0x01    /* enable DRC */
#define TUMBLER_DRC_DEFL_TH 0xa0    /* default compression threshold */

/*
 * Tumbler codec.
 */

struct tumbler_reg {
	u_char MCR[1];
        u_char DRC[2];
	u_char VOLUME[6];
	u_char TREBLE[1];
	u_char BASS[1];
	u_char MIXER1[3];
	u_char MIXER2[3];
	u_char LB0[15];
	u_char LB1[15];
	u_char LB2[15];
	u_char LB3[15];
	u_char LB4[15];
	u_char LB5[15];
	u_char RB0[15];
	u_char RB1[15];
	u_char RB2[15];
	u_char RB3[15];
	u_char RB4[15];
	u_char RB5[15];
};

const struct tumbler_reg tumbler_initdata = {
	{ TUMBLER_MCR_SC_64 | TUMBLER_MCR_SM_I2S | 
          TUMBLER_MCR_ISM_I2S | TUMBLER_MCR_W_16 },             /* MCR */
        { TUMBLER_DRC_COMP_31, TUMBLER_DRC_DEFL_TH },           /* DRC */
        { 0, 0, 0, 0, 0, 0 },				        /* VOLUME */
	{ 0x72 },						/* TREBLE */
	{ 0x3e },						/* BASS */
	{ 0x10, 0x00, 0x00 },	                		/* MIXER1 */
	{ 0x00, 0x00, 0x00 },		                	/* MIXER2 */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	/* BIQUAD */
	{ 0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }	/* BIQUAD */
};

const char tumbler_regsize[] = {
	0,					/* 0x00 */
	sizeof tumbler_initdata.MCR,		/* 0x01 */
        sizeof tumbler_initdata.DRC,            /* 0x02 */
	0,					/* 0x03 */
	sizeof tumbler_initdata.VOLUME,		/* 0x04 */
	sizeof tumbler_initdata.TREBLE,		/* 0x05 */
	sizeof tumbler_initdata.BASS,		/* 0x06 */
	sizeof tumbler_initdata.MIXER1, 	/* 0x07 */
	sizeof tumbler_initdata.MIXER2,	        /* 0x08 */
	0,					/* 0x09 */
	sizeof tumbler_initdata.LB0,		/* 0x0a */
	sizeof tumbler_initdata.LB1,		/* 0x0b */
	sizeof tumbler_initdata.LB2,		/* 0x0c */
	sizeof tumbler_initdata.LB3,		/* 0x0d */
	sizeof tumbler_initdata.LB4,		/* 0x0e */
	sizeof tumbler_initdata.LB5,		/* 0x0f */
	0,		                        /* 0x10 */
	0,					/* 0x11 */
	0,					/* 0x12 */
	sizeof tumbler_initdata.RB0,		/* 0x13 */
	sizeof tumbler_initdata.RB1,		/* 0x14 */
	sizeof tumbler_initdata.RB2,		/* 0x15 */
	sizeof tumbler_initdata.RB3,		/* 0x16 */
	sizeof tumbler_initdata.RB4,		/* 0x17 */
	sizeof tumbler_initdata.RB5		/* 0x18 */
};

/* dB = 20 * log (x) table. */
static u_int	tumbler_volume_table[100] = {      	
	0x00000148,   0x0000015C,   0x00000171,   0x00000186,   // -46.0,	-45.5,	-45.0,	-44.5,
	0x0000019E,   0x000001B6,   0x000001D0,   0x000001EB,   // -44.0,	-43.5,	-43.0,	-42.5,
	0x00000209,   0x00000227,   0x00000248,   0x0000026B,   // -42.0,	-41.5,	-41.0,	-40.5,
	0x0000028F,   0x000002B6,   0x000002DF,   0x0000030B,   // -40.0,	-39.5,	-39.0,	-38.5,
	0x00000339,   0x0000036A,   0x0000039E,   0x000003D5,   // -38.0,	-37.5,	-37.0,	-36.5,
	0x0000040F,   0x0000044C,   0x0000048D,   0x000004D2,   // -36.0,	-35.5,	-35.0,	-34.5,
	0x0000051C,   0x00000569,   0x000005BB,   0x00000612,   // -34.0,	-33.5,	-33.0,	-32.5,
	0x0000066E,   0x000006D0,   0x00000737,   0x000007A5,   // -32.0,	-31.5,	-31.0,	-30.5,
	0x00000818,   0x00000893,   0x00000915,   0x0000099F,   // -30.0,	-29.5,	-29.0,	-28.5,
	0x00000A31,   0x00000ACC,   0x00000B6F,   0x00000C1D,   // -28.0,	-27.5,	-27.0,	-26.5,
	0x00000CD5,   0x00000D97,   0x00000E65,   0x00000F40,   // -26.0,	-25.5,	-25.0,	-24.5,
	0x00001027,   0x0000111C,   0x00001220,   0x00001333,   // -24.0,	-23.5,	-23.0,	-22.5,
	0x00001456,   0x0000158A,   0x000016D1,   0x0000182B,   // -22.0,	-21.5,	-21.0,	-20.5,
	0x0000199A,   0x00001B1E,   0x00001CB9,   0x00001E6D,   // -20.0,	-19.5,	-19.0,	-18.5,
	0x0000203A,   0x00002223,   0x00002429,   0x0000264E,   // -18.0,	-17.5,	-17.0,	-16.5,
	0x00002893,   0x00002AFA,   0x00002D86,   0x00003039,   // -16.0,	-15.5,	-15.0,	-14.5,
	0x00003314,   0x0000361B,   0x00003950,   0x00003CB5,   // -14.0,	-13.5,	-13.0,	-12.5,
	0x0000404E,   0x0000441D,   0x00004827,   0x00004C6D,   // -12.0,	-11.5,	-11.0,	-10.5,
	0x000050F4,   0x000055C0,   0x00005AD5,   0x00006037,   // -10.0,	-9.5,	-9.0,	-8.5,
	0x000065EA,   0x00006BF4,   0x0000725A,   0x00007920,   // -8.0,	-7.5,	-7.0,	-6.5,
	0x0000804E,   0x000087EF,   0x00008FF6,   0x0000987D,   // -6.0,	-5.5,	-5.0,	-4.5,
	0x0000A186,   0x0000AB19,   0x0000B53C,   0x0000BFF9,   // -4.0,	-3.5,	-3.0,	-2.5,
	0x0000CB59,   0x0000D766,   0x0000E429,   0x0000F1AE,   // -2.0,	-1.5,	-1.0,	-0.5,
	0x00010000,   0x00010F2B,   0x00011F3D,   0x00013042,   // 0.0,   +0.5,	+1.0,	+1.5,
	0x00014249,   0x00015562,   0x0001699C,   0x00017F09    // 2.0,   +2.5,	+3.0,	+3.5,
};

static int
tumbler_write(struct tumbler_softc *sc, uint8_t reg, const void *data)
{
	u_int size;
	uint8_t buf[16];

	struct iic_msg msg[] = {
		{ sc->sc_addr, IIC_M_WR, 0, buf }
	};
		
	KASSERT(reg < sizeof(tumbler_regsize), ("bad reg"));
	size = tumbler_regsize[reg];
	msg[0].len = size + 1;
	buf[0] = reg;
	memcpy(&buf[1], data, size);

	iicbus_transfer(sc->sc_dev, msg, 1);

	return (0);
}

static int
tumbler_probe(device_t dev)
{
	const char *name;

	name = ofw_bus_get_name(dev);
	if (name == NULL)
		return (ENXIO);

	if (strcmp(name, "deq") == 0 && iicbus_get_addr(dev) == 
	    TUMBLER_IICADDR) {
		device_set_desc(dev, "Texas Instruments TAS3001 Audio Codec");
		return (0);
	}

	return (ENXIO);
}

static int
tumbler_attach(device_t dev)
{
	struct tumbler_softc *sc;
		
	sc = device_get_softc(dev);
	sc->sc_dev = dev;
	sc->sc_addr = iicbus_get_addr(dev);

	i2s_mixer_class = &tumbler_mixer_class;
	i2s_mixer = dev;

	return (0);
}

static int
tumbler_init(struct snd_mixer *m)
{
	struct tumbler_softc *sc;
	u_int		x = 0;

	sc = device_get_softc(mix_getdevinfo(m));

        tumbler_write(sc, TUMBLER_LB0, tumbler_initdata.LB0);
	tumbler_write(sc, TUMBLER_LB1, tumbler_initdata.LB1);
	tumbler_write(sc, TUMBLER_LB2, tumbler_initdata.LB2);
	tumbler_write(sc, TUMBLER_LB3, tumbler_initdata.LB3);
	tumbler_write(sc, TUMBLER_LB4, tumbler_initdata.LB4);
	tumbler_write(sc, TUMBLER_LB5, tumbler_initdata.LB5);
	tumbler_write(sc, TUMBLER_RB0, tumbler_initdata.RB0);
	tumbler_write(sc, TUMBLER_RB1, tumbler_initdata.RB1);
	tumbler_write(sc, TUMBLER_RB1, tumbler_initdata.RB1);
	tumbler_write(sc, TUMBLER_RB2, tumbler_initdata.RB2);
	tumbler_write(sc, TUMBLER_RB3, tumbler_initdata.RB3);
	tumbler_write(sc, TUMBLER_RB4, tumbler_initdata.RB4);
	tumbler_write(sc, TUMBLER_RB5, tumbler_initdata.RB5);
	tumbler_write(sc, TUMBLER_MCR, tumbler_initdata.MCR);
	tumbler_write(sc, TUMBLER_DRC, tumbler_initdata.DRC);
        tumbler_write(sc, TUMBLER_VOLUME, tumbler_initdata.VOLUME);
	tumbler_write(sc, TUMBLER_TREBLE, tumbler_initdata.TREBLE);
	tumbler_write(sc, TUMBLER_BASS, tumbler_initdata.BASS);
	tumbler_write(sc, TUMBLER_MIXER1, tumbler_initdata.MIXER1);
	tumbler_write(sc, TUMBLER_MIXER2, tumbler_initdata.MIXER2);

	x |= SOUND_MASK_VOLUME;
	mix_setdevs(m, x);

	return (0);
}

static int
tumbler_uninit(struct snd_mixer *m)
{
	return (0);
}

static int
tumbler_reinit(struct snd_mixer *m)
{
	return (0);
}

static int
tumbler_set(struct snd_mixer *m, unsigned dev, unsigned left, unsigned right)
{
	struct tumbler_softc *sc;
	struct mtx *mixer_lock;
	int locked;
	u_int l, r;
	u_char reg[6];

	sc = device_get_softc(mix_getdevinfo(m));
	mixer_lock = mixer_get_lock(m);
	locked = mtx_owned(mixer_lock);

	switch (dev) {
	case SOUND_MIXER_VOLUME:
		if (left > 100 || right > 100)
			return (0);

		l = (left == 0 ? 0 : tumbler_volume_table[left - 1]);
		r = (right == 0 ? 0 : tumbler_volume_table[right - 1]);
		
		reg[0] = (l & 0xff0000) >> 16;
		reg[1] = (l & 0x00ff00) >> 8;
		reg[2] = l & 0x0000ff;
		reg[3] = (r & 0xff0000) >> 16;
		reg[4] = (r & 0x00ff00) >> 8;
		reg[5] = r & 0x0000ff;

		/*
		 * We need to unlock the mixer lock because iicbus_transfer()
		 * may sleep. The mixer lock itself is unnecessary here
		 * because it is meant to serialize hardware access, which
		 * is taken care of by the I2C layer, so this is safe.
		 */

		if (locked)
			mtx_unlock(mixer_lock);

		tumbler_write(sc, TUMBLER_VOLUME, reg);

		if (locked)
			mtx_lock(mixer_lock);

		return (left | (right << 8));
	}

	return (0);
}

static u_int32_t
tumbler_setrecsrc(struct snd_mixer *m, u_int32_t src)
{
	return (0);
}