aboutsummaryrefslogtreecommitdiffstats
path: root/sound/aoa/codecs/snd-aoa-codec-tas.c
blob: 23643b342cb0d5abd3259d9b506fc9d0c81e5493 (plain) (blame)
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
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
/*
 * Apple Onboard Audio driver for tas codec
 *
 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
 *
 * GPL v2, can be found in COPYING.
 *
 * Open questions:
 *  - How to distinguish between 3004 and versions?
 *
 * FIXMEs:
 *  - This codec driver doesn't honour the 'connected'
 *    property of the aoa_codec struct, hence if
 *    it is used in machines where not everything is
 *    connected it will display wrong mixer elements.
 *  - Driver assumes that the microphone is always
 *    monaureal and connected to the right channel of
 *    the input. This should also be a codec-dependent
 *    flag, maybe the codec should have 3 different
 *    bits for the three different possibilities how
 *    it can be hooked up...
 *    But as long as I don't see any hardware hooked
 *    up that way...
 *  - As Apple notes in their code, the tas3004 seems
 *    to delay the right channel by one sample. You can
 *    see this when for example recording stereo in
 *    audacity, or recording the tas output via cable
 *    on another machine (use a sinus generator or so).
 *    I tried programming the BiQuads but couldn't
 *    make the delay work, maybe someone can read the
 *    datasheet and fix it. The relevant Apple comment
 *    is in AppleTAS3004Audio.cpp lines 1637 ff. Note
 *    that their comment describing how they program
 *    the filters sucks...
 *
 * Other things:
 *  - this should actually register *two* aoa_codec
 *    structs since it has two inputs. Then it must
 *    use the prepare callback to forbid running the
 *    secondary output on a different clock.
 *    Also, whatever bus knows how to do this must
 *    provide two soundbus_dev devices and the fabric
 *    must be able to link them correctly.
 *
 *    I don't even know if Apple ever uses the second
 *    port on the tas3004 though, I don't think their
 *    i2s controllers can even do it. OTOH, they all
 *    derive the clocks from common clocks, so it
 *    might just be possible. The framework allows the
 *    codec to refine the transfer_info items in the
 *    usable callback, so we can simply remove the
 *    rates the second instance is not using when it
 *    actually is in use.
 *    Maybe we'll need to make the sound busses have
 *    a 'clock group id' value so the codec can
 *    determine if the two outputs can be driven at
 *    the same time. But that is likely overkill, up
 *    to the fabric to not link them up incorrectly,
 *    and up to the hardware designer to not wire
 *    them up in some weird unusable way.
 */
#include <stddef.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <asm/pmac_low_i2c.h>
#include <asm/prom.h>
#include <linux/delay.h>
#include <linux/module.h>
MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("tas codec driver for snd-aoa");

#include "snd-aoa-codec-tas.h"
#include "snd-aoa-codec-tas-gain-table.h"
#include "../aoa.h"
#include "../soundbus/soundbus.h"

#define PFX "snd-aoa-codec-tas: "


struct tas {
	struct aoa_codec	codec;
	struct i2c_client	i2c;
	u32			mute_l:1, mute_r:1 ,
				controls_created:1 ,
				drc_enabled:1,
				hw_enabled:1;
	u8			cached_volume_l, cached_volume_r;
	u8			mixer_l[3], mixer_r[3];
	u8			acr;
	int			drc_range;
};

static int tas_reset_init(struct tas *tas);

static struct tas *codec_to_tas(struct aoa_codec *codec)
{
	return container_of(codec, struct tas, codec);
}

static inline int tas_write_reg(struct tas *tas, u8 reg, u8 len, u8 *data)
{
	if (len == 1)
		return i2c_smbus_write_byte_data(&tas->i2c, reg, *data);
	else
		return i2c_smbus_write_i2c_block_data(&tas->i2c, reg, len, data);
}

static void tas3004_set_drc(struct tas *tas)
{
	unsigned char val[6];

	if (tas->drc_enabled)
		val[0] = 0x50; /* 3:1 above threshold */
	else
		val[0] = 0x51; /* disabled */
	val[1] = 0x02; /* 1:1 below threshold */
	if (tas->drc_range > 0xef)
		val[2] = 0xef;
	else if (tas->drc_range < 0)
		val[2] = 0x00;
	else
		val[2] = tas->drc_range;
	val[3] = 0xb0;
	val[4] = 0x60;
	val[5] = 0xa0;

	tas_write_reg(tas, TAS_REG_DRC, 6, val);
}

static void tas_set_volume(struct tas *tas)
{
	u8 block[6];
	int tmp;
	u8 left, right;

	left = tas->cached_volume_l;
	right = tas->cached_volume_r;

	if (left > 177) left = 177;
	if (right > 177) right = 177;

	if (tas->mute_l) left = 0;
	if (tas->mute_r) right = 0;

	/* analysing the volume and mixer tables shows
	 * that they are similar enough when we shift
	 * the mixer table down by 4 bits. The error
	 * is miniscule, in just one item the error
	 * is 1, at a value of 0x07f17b (mixer table
	 * value is 0x07f17a) */
	tmp = tas_gaintable[left];
	block[0] = tmp>>20;
	block[1] = tmp>>12;
	block[2] = tmp>>4;
	tmp = tas_gaintable[right];
	block[3] = tmp>>20;
	block[4] = tmp>>12;
	block[5] = tmp>>4;
	tas_write_reg(tas, TAS_REG_VOL, 6, block);
}

static void tas_set_mixer(struct tas *tas)
{
	u8 block[9];
	int tmp, i;
	u8 val;

	for (i=0;i<3;i++) {
		val = tas->mixer_l[i];
		if (val > 177) val = 177;
		tmp = tas_gaintable[val];
		block[3*i+0] = tmp>>16;
		block[3*i+1] = tmp>>8;
		block[3*i+2] = tmp;
	}
	tas_write_reg(tas, TAS_REG_LMIX, 9, block);

	for (i=0;i<3;i++) {
		val = tas->mixer_r[i];
		if (val > 177) val = 177;
		tmp = tas_gaintable[val];
		block[3*i+0] = tmp>>16;
		block[3*i+1] = tmp>>8;
		block[3*i+2] = tmp;
	}
	tas_write_reg(tas, TAS_REG_RMIX, 9, block);
}

/* alsa stuff */

static int tas_dev_register(struct snd_device *dev)
{
	return 0;
}

static struct snd_device_ops ops = {
	.dev_register = tas_dev_register,
};

static int tas_snd_vol_info(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
	uinfo->count = 2;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 177;
	return 0;
}

static int tas_snd_vol_get(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);

	ucontrol->value.integer.value[0] = tas->cached_volume_l;
	ucontrol->value.integer.value[1] = tas->cached_volume_r;
	return 0;
}

static int tas_snd_vol_put(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);

	if (tas->cached_volume_l == ucontrol->value.integer.value[0]
	 && tas->cached_volume_r == ucontrol->value.integer.value[1])
		return 0;

	tas->cached_volume_l = ucontrol->value.integer.value[0];
	tas->cached_volume_r = ucontrol->value.integer.value[1];
	if (tas->hw_enabled)
		tas_set_volume(tas);
	return 1;
}

static struct snd_kcontrol_new volume_control = {
	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
	.name = "Master Playback Volume",
	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
	.info = tas_snd_vol_info,
	.get = tas_snd_vol_get,
	.put = tas_snd_vol_put,
};

static int tas_snd_mute_info(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 2;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}

static int tas_snd_mute_get(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);

	ucontrol->value.integer.value[0] = !tas->mute_l;
	ucontrol->value.integer.value[1] = !tas->mute_r;
	return 0;
}

static int tas_snd_mute_put(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);

	if (tas->mute_l == !ucontrol->value.integer.value[0]
	 && tas->mute_r == !ucontrol->value.integer.value[1])
		return 0;

	tas->mute_l = !ucontrol->value.integer.value[0];
	tas->mute_r = !ucontrol->value.integer.value[1];
	if (tas->hw_enabled)
		tas_set_volume(tas);
	return 1;
}

static struct snd_kcontrol_new mute_control = {
	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
	.name = "Master Playback Switch",
	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
	.info = tas_snd_mute_info,
	.get = tas_snd_mute_get,
	.put = tas_snd_mute_put,
};

static int tas_snd_mixer_info(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
	uinfo->count = 2;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 177;
	return 0;
}

static int tas_snd_mixer_get(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);
	int idx = kcontrol->private_value;

	ucontrol->value.integer.value[0] = tas->mixer_l[idx];
	ucontrol->value.integer.value[1] = tas->mixer_r[idx];

	return 0;
}

static int tas_snd_mixer_put(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);
	int idx = kcontrol->private_value;

	if (tas->mixer_l[idx] == ucontrol->value.integer.value[0]
	 && tas->mixer_r[idx] == ucontrol->value.integer.value[1])
		return 0;

	tas->mixer_l[idx] = ucontrol->value.integer.value[0];
	tas->mixer_r[idx] = ucontrol->value.integer.value[1];

	if (tas->hw_enabled)
		tas_set_mixer(tas);
	return 1;
}

#define MIXER_CONTROL(n,descr,idx)			\
static struct snd_kcontrol_new n##_control = {		\
	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,		\
	.name = descr " Playback Volume",		\
	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,	\
	.info = tas_snd_mixer_info,			\
	.get = tas_snd_mixer_get,			\
	.put = tas_snd_mixer_put,			\
	.private_value = idx,				\
}

MIXER_CONTROL(pcm1, "PCM", 0);
MIXER_CONTROL(monitor, "Monitor", 2);

static int tas_snd_capture_source_info(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_info *uinfo)
{
	static char *texts[] = { "Line-In", "Microphone" };

	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
	uinfo->count = 1;
	uinfo->value.enumerated.items = 2;
	if (uinfo->value.enumerated.item > 1)
		uinfo->value.enumerated.item = 1;
	strcpy(uinfo->value.enumerated.name, texts[uinfo->value.enumerated.item]);
	return 0;
}

static int tas_snd_capture_source_get(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);

	ucontrol->value.enumerated.item[0] = !!(tas->acr & TAS_ACR_INPUT_B);
	return 0;
}

static int tas_snd_capture_source_put(struct snd_kcontrol *kcontrol,
	struct snd_ctl_elem_value *ucontrol)
{
	struct tas *tas = snd_kcontrol_chip(kcontrol);
	int oldacr = tas->acr;

	tas->acr &= ~TAS_ACR_INPUT_B;
	if (ucontrol->value.enumerated.item[0])
		tas->acr |= TAS_ACR_INPUT_B;
	if (oldacr == tas->acr)
		return 0;
	if (tas->hw_enabled)
		tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr);
	return 1;
}

static struct snd_kcontrol_new capture_source_control = {
	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
	/* If we name this 'Input Source', it properly shows up in
	 * alsamixer as a selection, * but it's shown under the
	 * 'Playback' category.
	 * If I name it 'Capture Source', it shows up in strange
	 * ways (two bools of which one can be selected at a
	 * time) but at least it's shown in the 'Capture'
	 * category.
	 * I was told that this was due to backward compatibility,
	 * but I don't understand then why the mangling is *not*
	 * done when I name it "Input Source".....
	 */
	.name = "Capture Source",
	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
	.info = tas_snd_capture_source_info,
	.get = tas_snd_capture_source_get,
	.put = tas_snd_capture_source_put,
};


static struct transfer_info tas_transfers[] = {
	{
		/* input */
		.formats = SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S16_BE |
			   SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_BE,
		.rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
		.transfer_in = 1,
	},
	{
		/* output */
		.formats = SNDRV_PCM_FMTBIT_S16_BE | SNDRV_PCM_FMTBIT_S16_BE |
			   SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_BE,
		.rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
		.transfer_in = 0,
	},
	{}
};

static int tas_usable(struct codec_info_item *cii,
		      struct transfer_info *ti,
		      struct transfer_info *out)
{
	return 1;
}

static int tas_reset_init(struct tas *tas)
{
	u8 tmp;

	tas->codec.gpio->methods->all_amps_off(tas->codec.gpio);
	msleep(5);
	tas->codec.gpio->methods->set_hw_reset(tas->codec.gpio, 0);
	msleep(5);
	tas->codec.gpio->methods->set_hw_reset(tas->codec.gpio, 1);
	msleep(20);
	tas->codec.gpio->methods->set_hw_reset(tas->codec.gpio, 0);
	msleep(10);
	tas->codec.gpio->methods->all_amps_restore(tas->codec.gpio);

	tmp = TAS_MCS_SCLK64 | TAS_MCS_SPORT_MODE_I2S | TAS_MCS_SPORT_WL_24BIT;
	if (tas_write_reg(tas, TAS_REG_MCS, 1, &tmp))
		return -ENODEV;

	tas->acr |= TAS_ACR_ANALOG_PDOWN | TAS_ACR_B_MONAUREAL |
		TAS_ACR_B_MON_SEL_RIGHT;
	if (tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr))
		return -ENODEV;

	tmp = 0;
	if (tas_write_reg(tas, TAS_REG_MCS2, 1, &tmp))
		return -ENODEV;

	tas3004_set_drc(tas);

	/* Set treble & bass to 0dB */
	tmp = 114;
	tas_write_reg(tas, TAS_REG_TREBLE, 1, &tmp);
	tas_write_reg(tas, TAS_REG_BASS, 1, &tmp);

	tas->acr &= ~TAS_ACR_ANALOG_PDOWN;
	if (tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr))
		return -ENODEV;

	return 0;
}

static int tas_switch_clock(struct codec_info_item *cii, enum clock_switch clock)
{
	struct tas *tas = cii->codec_data;

	switch(clock) {
	case CLOCK_SWITCH_PREPARE_SLAVE:
		/* Clocks are going away, mute mute mute */
		tas->codec.gpio->methods->all_amps_off(tas->codec.gpio);
		tas->hw_enabled = 0;
		break;
	case CLOCK_SWITCH_SLAVE:
		/* Clocks are back, re-init the codec */
		tas_reset_init(tas);
		tas_set_volume(tas);
		tas_set_mixer(tas);
		tas->hw_enabled = 1;
		tas->codec.gpio->methods->all_amps_restore(tas->codec.gpio);
		break;
	default:
		/* doesn't happen as of now */
		return -EINVAL;
	}
	return 0;
}

/* we are controlled via i2c and assume that is always up
 * If that wasn't the case, we'd have to suspend once
 * our i2c device is suspended, and then take note of that! */
static int tas_suspend(struct tas *tas)
{
	tas->hw_enabled = 0;
	tas->acr |= TAS_ACR_ANALOG_PDOWN;
	tas_write_reg(tas, TAS_REG_ACR, 1, &tas->acr);
	return 0;
}

static int tas_resume(struct tas *tas)
{
	/* reset codec */
	tas_reset_init(tas);
	tas_set_volume(tas);
	tas_set_mixer(tas);
	tas->hw_enabled = 1;
	return 0;
}

#ifdef CONFIG_PM
static int _tas_suspend(struct codec_info_item *cii, pm_message_t state)
{
	return tas_suspend(cii->codec_data);
}

static int _tas_resume(struct codec_info_item *cii)
{
	return tas_resume(cii->codec_data);
}
#endif

static struct codec_info tas_codec_info = {
	.transfers = tas_transfers,
	/* in theory, we can drive it at 512 too...
	 * but so far the framework doesn't allow
	 * for that and I don't see much point in it. */
	.sysclock_factor = 256,
	/* same here, could be 32 for just one 16 bit format */
	.bus_factor = 64,
	.owner = THIS_MODULE,
	.usable = tas_usable,
	.switch_clock = tas_switch_clock,
#ifdef CONFIG_PM
	.suspend = _tas_suspend,
	.resume = _tas_resume,
#endif
};

static int tas_init_codec(struct aoa_codec *codec)
{
	struct tas *tas = codec_to_tas(codec);
	int err;

	if (!tas->codec.gpio || !tas->codec.gpio->methods) {
		printk(KERN_ERR PFX "gpios not assigned!!\n");
		return -EINVAL;
	}

	if (tas_reset_init(tas)) {
		printk(KERN_ERR PFX "tas failed to initialise\n");
		return -ENXIO;
	}
	tas->hw_enabled = 1;

	if (tas->codec.soundbus_dev->attach_codec(tas->codec.soundbus_dev,
						   aoa_get_card(),
						   &tas_codec_info, tas)) {
		printk(KERN_ERR PFX "error attaching tas to soundbus\n");
		return -ENODEV;
	}

	if (aoa_snd_device_new(SNDRV_DEV_LOWLEVEL, tas, &ops)) {
		printk(KERN_ERR PFX "failed to create tas snd device!\n");
		return -ENODEV;
	}
	err = aoa_snd_ctl_add(snd_ctl_new1(&volume_control, tas));
	if (err)
		goto error;

	err = aoa_snd_ctl_add(snd_ctl_new1(&mute_control, tas));
	if (err)
		goto error;

	err = aoa_snd_ctl_add(snd_ctl_new1(&pcm1_control, tas));
	if (err)
		goto error;

	err = aoa_snd_ctl_add(snd_ctl_new1(&monitor_control, tas));
	if (err)
		goto error;

	err = aoa_snd_ctl_add(snd_ctl_new1(&capture_source_control, tas));
	if (err)
		goto error;

	return 0;
 error:
	tas->codec.soundbus_dev->detach_codec(tas->codec.soundbus_dev, tas);
	snd_device_free(aoa_get_card(), tas);
	return err;
}

static void tas_exit_codec(struct aoa_codec *codec)
{
	struct tas *tas = codec_to_tas(codec);

	if (!tas->codec.soundbus_dev)
		return;
	tas->codec.soundbus_dev->detach_codec(tas->codec.soundbus_dev, tas);
}
	

static struct i2c_driver tas_driver;

static int tas_create(struct i2c_adapter *adapter,
		       struct device_node *node,
		       int addr)
{
	struct tas *tas;

	tas = kzalloc(sizeof(struct tas), GFP_KERNEL);

	if (!tas)
		return -ENOMEM;

	tas->i2c.driver = &tas_driver;
	tas->i2c.adapter = adapter;
	tas->i2c.addr = addr;
	tas->drc_range = TAS3004_DRC_MAX;
	strlcpy(tas->i2c.name, "tas audio codec", I2C_NAME_SIZE-1);

	if (i2c_attach_client(&tas->i2c)) {
		printk(KERN_ERR PFX "failed to attach to i2c\n");
		goto fail;
	}

	strlcpy(tas->codec.name, "tas", MAX_CODEC_NAME_LEN-1);
	tas->codec.owner = THIS_MODULE;
	tas->codec.init = tas_init_codec;
	tas->codec.exit = tas_exit_codec;
	tas->codec.node = of_node_get(node);

	if (aoa_codec_register(&tas->codec)) {
		goto detach;
	}
	printk(KERN_DEBUG
	       "snd-aoa-codec-tas: tas found, addr 0x%02x on %s\n",
	       addr, node->full_name);
	return 0;
 detach:
	i2c_detach_client(&tas->i2c);
 fail:
	kfree(tas);
	return -EINVAL;
}

static int tas_i2c_attach(struct i2c_adapter *adapter)
{
	struct device_node *busnode, *dev = NULL;
	struct pmac_i2c_bus *bus;

	bus = pmac_i2c_adapter_to_bus(adapter);
	if (bus == NULL)
		return -ENODEV;
	busnode = pmac_i2c_get_bus_node(bus);

	while ((dev = of_get_next_child(busnode, dev)) != NULL) {
		if (device_is_compatible(dev, "tas3004")) {
			u32 *addr;
			printk(KERN_DEBUG PFX "found tas3004\n");
			addr = (u32 *) get_property(dev, "reg", NULL);
			if (!addr)
				continue;
			return tas_create(adapter, dev, ((*addr) >> 1) & 0x7f);
		}
		/* older machines have no 'codec' node with a 'compatible'
		 * property that says 'tas3004', they just have a 'deq'
		 * node without any such property... */
		if (strcmp(dev->name, "deq") == 0) {
			u32 *_addr, addr;
			printk(KERN_DEBUG PFX "found 'deq' node\n");
			_addr = (u32 *) get_property(dev, "i2c-address", NULL);
			if (!_addr)
				continue;
			addr = ((*_addr) >> 1) & 0x7f;
			/* now, if the address doesn't match any of the two
			 * that a tas3004 can have, we cannot handle this.
			 * I doubt it ever happens but hey. */
			if (addr != 0x34 && addr != 0x35)
				continue;
			return tas_create(adapter, dev, addr);
		}
	}
	return -ENODEV;
}

static int tas_i2c_detach(struct i2c_client *client)
{
	struct tas *tas = container_of(client, struct tas, i2c);
	int err;
	u8 tmp = TAS_ACR_ANALOG_PDOWN;

	if ((err = i2c_detach_client(client)))
		return err;
	aoa_codec_unregister(&tas->codec);
	of_node_put(tas->codec.node);

	/* power down codec chip */
	tas_write_reg(tas, TAS_REG_ACR, 1, &tmp);

	kfree(tas);
	return 0;
}

static struct i2c_driver tas_driver = {
	.driver = {
		.name = "aoa_codec_tas",
		.owner = THIS_MODULE,
	},
	.attach_adapter = tas_i2c_attach,
	.detach_client = tas_i2c_detach,
};

static int __init tas_init(void)
{
	return i2c_add_driver(&tas_driver);
}

static void __exit tas_exit(void)
{
	i2c_del_driver(&tas_driver);
}

module_init(tas_init);
module_exit(tas_exit);