aboutsummaryrefslogtreecommitdiff
path: root/drivers/regulator/lp3972.c
blob: e07062fd0b42aa3bdebc6faee0285b3ab1fb11ba (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
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
/*
 * Regulator driver for National Semiconductors LP3972 PMIC chip
 *
 * Based on lp3971.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/bug.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/lp3972.h>
#include <linux/slab.h>

struct lp3972 {
	struct device *dev;
	struct mutex io_lock;
	struct i2c_client *i2c;
	int num_regulators;
	struct regulator_dev **rdev;
};

/* LP3972 Control Registers */
#define LP3972_SCR_REG		0x07
#define LP3972_OVER1_REG	0x10
#define LP3972_OVSR1_REG	0x11
#define LP3972_OVER2_REG	0x12
#define LP3972_OVSR2_REG	0x13
#define LP3972_VCC1_REG		0x20
#define LP3972_ADTV1_REG	0x23
#define LP3972_ADTV2_REG	0x24
#define LP3972_AVRC_REG		0x25
#define LP3972_CDTC1_REG	0x26
#define LP3972_CDTC2_REG	0x27
#define LP3972_SDTV1_REG	0x29
#define LP3972_SDTV2_REG	0x2A
#define LP3972_MDTV1_REG	0x32
#define LP3972_MDTV2_REG	0x33
#define LP3972_L2VCR_REG	0x39
#define LP3972_L34VCR_REG	0x3A
#define LP3972_SCR1_REG		0x80
#define LP3972_SCR2_REG		0x81
#define LP3972_OEN3_REG		0x82
#define LP3972_OSR3_REG		0x83
#define LP3972_LOER4_REG	0x84
#define LP3972_B2TV_REG		0x85
#define LP3972_B3TV_REG		0x86
#define LP3972_B32RC_REG	0x87
#define LP3972_ISRA_REG		0x88
#define LP3972_BCCR_REG		0x89
#define LP3972_II1RR_REG	0x8E
#define LP3972_II2RR_REG	0x8F

#define LP3972_SYS_CONTROL1_REG		LP3972_SCR1_REG
/* System control register 1 initial value,
 * bits 5, 6 and 7 are EPROM programmable */
#define SYS_CONTROL1_INIT_VAL		0x02
#define SYS_CONTROL1_INIT_MASK		0x1F

#define LP3972_VOL_CHANGE_REG		LP3972_VCC1_REG
#define LP3972_VOL_CHANGE_FLAG_GO	0x01
#define LP3972_VOL_CHANGE_FLAG_MASK	0x03

/* LDO output enable mask */
#define LP3972_OEN3_L1EN	BIT(0)
#define LP3972_OVER2_LDO2_EN	BIT(2)
#define LP3972_OVER2_LDO3_EN	BIT(3)
#define LP3972_OVER2_LDO4_EN	BIT(4)
#define LP3972_OVER1_S_EN	BIT(2)

static const int ldo1_voltage_map[] = {
	1700, 1725, 1750, 1775, 1800, 1825, 1850, 1875,
	1900, 1925, 1950, 1975, 2000,
};

static const int ldo23_voltage_map[] = {
	1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500,
	2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300,
};

static const int ldo4_voltage_map[] = {
	1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350,
	1400, 1500, 1800, 1900, 2500, 2800, 3000, 3300,
};

static const int ldo5_voltage_map[] = {
	   0,    0,    0,    0,    0,  850,  875,  900,
	 925,  950,  975, 1000, 1025, 1050, 1075, 1100,
	1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300,
	1325, 1350, 1375, 1400, 1425, 1450, 1475, 1500,
};

static const int buck1_voltage_map[] = {
	 725,  750,  775,  800,  825,  850,  875,  900,
	 925,  950,  975, 1000, 1025, 1050, 1075, 1100,
	1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300,
	1325, 1350, 1375, 1400, 1425, 1450, 1475, 1500,
};

static const int buck23_voltage_map[] = {
	   0,  800,  850,  900,  950, 1000, 1050, 1100,
	1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500,
	1550, 1600, 1650, 1700, 1800, 1900, 2500, 2800,
	3000, 3300,
};

static const int *ldo_voltage_map[] = {
	ldo1_voltage_map,
	ldo23_voltage_map,
	ldo23_voltage_map,
	ldo4_voltage_map,
	ldo5_voltage_map,
};

static const int *buck_voltage_map[] = {
	buck1_voltage_map,
	buck23_voltage_map,
	buck23_voltage_map,
};

static const int ldo_output_enable_mask[] = {
	LP3972_OEN3_L1EN,
	LP3972_OVER2_LDO2_EN,
	LP3972_OVER2_LDO3_EN,
	LP3972_OVER2_LDO4_EN,
	LP3972_OVER1_S_EN,
};

static const int ldo_output_enable_addr[] = {
	LP3972_OEN3_REG,
	LP3972_OVER2_REG,
	LP3972_OVER2_REG,
	LP3972_OVER2_REG,
	LP3972_OVER1_REG,
};

static const int ldo_vol_ctl_addr[] = {
	LP3972_MDTV1_REG,
	LP3972_L2VCR_REG,
	LP3972_L34VCR_REG,
	LP3972_L34VCR_REG,
	LP3972_SDTV1_REG,
};

static const int buck_vol_enable_addr[] = {
	LP3972_OVER1_REG,
	LP3972_OEN3_REG,
	LP3972_OEN3_REG,
};

static const int buck_base_addr[] = {
	LP3972_ADTV1_REG,
	LP3972_B2TV_REG,
	LP3972_B3TV_REG,
};

#define LP3972_LDO_VOL_VALUE_MAP(x) (ldo_voltage_map[x])
#define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
#define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])

/*	LDO voltage control registers shift:
	LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
	LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
	LP3972_LDO5 -> 0
*/
#define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
#define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
#define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)

#define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
#define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
#define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)

#define LP3972_BUCK_VOL_VALUE_MAP(x) (buck_voltage_map[x])
#define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
#define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
#define LP3972_BUCK_VOL_MASK 0x1f
#define LP3972_BUCK_VOL_MIN_IDX(x) ((x) ? 0x01 : 0x00)
#define LP3972_BUCK_VOL_MAX_IDX(x) ((x) ? 0x19 : 0x1f)

static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
	u16 *dest)
{
	int ret;

	if (count != 1)
		return -EIO;
	ret = i2c_smbus_read_byte_data(i2c, reg);
	if (ret < 0)
		return ret;

	*dest = ret;
	return 0;
}

static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
	const u16 *src)
{
	if (count != 1)
		return -EIO;
	return i2c_smbus_write_byte_data(i2c, reg, *src);
}

static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
{
	u16 val = 0;

	mutex_lock(&lp3972->io_lock);

	lp3972_i2c_read(lp3972->i2c, reg, 1, &val);

	dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
		(unsigned)val & 0xff);

	mutex_unlock(&lp3972->io_lock);

	return val & 0xff;
}

static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
{
	u16 tmp;
	int ret;

	mutex_lock(&lp3972->io_lock);

	ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
	tmp = (tmp & ~mask) | val;
	if (ret == 0) {
		ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
		dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
			(unsigned)val & 0xff);
	}
	mutex_unlock(&lp3972->io_lock);

	return ret;
}

static int lp3972_ldo_list_voltage(struct regulator_dev *dev, unsigned index)
{
	int ldo = rdev_get_id(dev) - LP3972_LDO1;
	return 1000 * LP3972_LDO_VOL_VALUE_MAP(ldo)[index];
}

static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int ldo = rdev_get_id(dev) - LP3972_LDO1;
	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
	u16 val;

	val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
	return !!(val & mask);
}

static int lp3972_ldo_enable(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int ldo = rdev_get_id(dev) - LP3972_LDO1;
	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);

	return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
				mask, mask);
}

static int lp3972_ldo_disable(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int ldo = rdev_get_id(dev) - LP3972_LDO1;
	u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);

	return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
				mask, 0);
}

static int lp3972_ldo_get_voltage(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int ldo = rdev_get_id(dev) - LP3972_LDO1;
	u16 mask = LP3972_LDO_VOL_MASK(ldo);
	u16 val, reg;

	reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
	val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;

	return 1000 * LP3972_LDO_VOL_VALUE_MAP(ldo)[val];
}

static int lp3972_ldo_set_voltage(struct regulator_dev *dev,
				  int min_uV, int max_uV)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int ldo = rdev_get_id(dev) - LP3972_LDO1;
	int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
	const int *vol_map = LP3972_LDO_VOL_VALUE_MAP(ldo);
	u16 val;
	int shift, ret;

	if (min_vol < vol_map[LP3972_LDO_VOL_MIN_IDX(ldo)] ||
	    min_vol > vol_map[LP3972_LDO_VOL_MAX_IDX(ldo)])
		return -EINVAL;

	for (val = LP3972_LDO_VOL_MIN_IDX(ldo);
		val <= LP3972_LDO_VOL_MAX_IDX(ldo); val++)
		if (vol_map[val] >= min_vol)
			break;

	if (val > LP3972_LDO_VOL_MAX_IDX(ldo) || vol_map[val] > max_vol)
		return -EINVAL;

	shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
	ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),
		LP3972_LDO_VOL_MASK(ldo) << shift, val << shift);

	if (ret)
		return ret;

	/*
	 * LDO1 and LDO5 support voltage control by either target voltage1
	 * or target voltage2 register.
	 * We use target voltage1 register for LDO1 and LDO5 in this driver.
	 * We need to update voltage change control register(0x20) to enable
	 * LDO1 and LDO5 to change to their programmed target values.
	 */
	switch (ldo) {
	case LP3972_LDO1:
	case LP3972_LDO5:
		shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
		ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
			LP3972_VOL_CHANGE_FLAG_MASK << shift,
			LP3972_VOL_CHANGE_FLAG_GO << shift);
		if (ret)
			return ret;

		ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
			LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
		break;
	}

	return ret;
}

static struct regulator_ops lp3972_ldo_ops = {
	.list_voltage = lp3972_ldo_list_voltage,
	.is_enabled = lp3972_ldo_is_enabled,
	.enable = lp3972_ldo_enable,
	.disable = lp3972_ldo_disable,
	.get_voltage = lp3972_ldo_get_voltage,
	.set_voltage = lp3972_ldo_set_voltage,
};

static int lp3972_dcdc_list_voltage(struct regulator_dev *dev, unsigned index)
{
	int buck = rdev_get_id(dev) - LP3972_DCDC1;
	return 1000 * buck_voltage_map[buck][index];
}

static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int buck = rdev_get_id(dev) - LP3972_DCDC1;
	u16 mask = 1 << (buck * 2);
	u16 val;

	val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
	return !!(val & mask);
}

static int lp3972_dcdc_enable(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int buck = rdev_get_id(dev) - LP3972_DCDC1;
	u16 mask = 1 << (buck * 2);
	u16 val;

	val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
				mask, mask);
	return val;
}

static int lp3972_dcdc_disable(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int buck = rdev_get_id(dev) - LP3972_DCDC1;
	u16 mask = 1 << (buck * 2);
	u16 val;

	val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
				mask, 0);
	return val;
}

static int lp3972_dcdc_get_voltage(struct regulator_dev *dev)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int buck = rdev_get_id(dev) - LP3972_DCDC1;
	u16 reg;
	int val;

	reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
	reg &= LP3972_BUCK_VOL_MASK;
	if (reg <= LP3972_BUCK_VOL_MAX_IDX(buck))
		val = 1000 * buck_voltage_map[buck][reg];
	else {
		val = 0;
		dev_warn(&dev->dev, "chip reported incorrect voltage value."
				    " reg = %d\n", reg);
	}

	return val;
}

static int lp3972_dcdc_set_voltage(struct regulator_dev *dev,
				  int min_uV, int max_uV)
{
	struct lp3972 *lp3972 = rdev_get_drvdata(dev);
	int buck = rdev_get_id(dev) - LP3972_DCDC1;
	int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
	const int *vol_map = buck_voltage_map[buck];
	u16 val;
	int ret;

	if (min_vol < vol_map[LP3972_BUCK_VOL_MIN_IDX(buck)] ||
	    min_vol > vol_map[LP3972_BUCK_VOL_MAX_IDX(buck)])
		return -EINVAL;

	for (val = LP3972_BUCK_VOL_MIN_IDX(buck);
		val <= LP3972_BUCK_VOL_MAX_IDX(buck); val++)
		if (vol_map[val] >= min_vol)
			break;

	if (val > LP3972_BUCK_VOL_MAX_IDX(buck) ||
	    vol_map[val] > max_vol)
		return -EINVAL;

	ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),
				LP3972_BUCK_VOL_MASK, val);
	if (ret)
		return ret;

	if (buck != 0)
		return ret;

	ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
		LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
	if (ret)
		return ret;

	return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
				LP3972_VOL_CHANGE_FLAG_MASK, 0);
}

static struct regulator_ops lp3972_dcdc_ops = {
	.list_voltage = lp3972_dcdc_list_voltage,
	.is_enabled = lp3972_dcdc_is_enabled,
	.enable = lp3972_dcdc_enable,
	.disable = lp3972_dcdc_disable,
	.get_voltage = lp3972_dcdc_get_voltage,
	.set_voltage = lp3972_dcdc_set_voltage,
};

static struct regulator_desc regulators[] = {
	{
		.name = "LDO1",
		.id = LP3972_LDO1,
		.ops = &lp3972_ldo_ops,
		.n_voltages = ARRAY_SIZE(ldo1_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "LDO2",
		.id = LP3972_LDO2,
		.ops = &lp3972_ldo_ops,
		.n_voltages = ARRAY_SIZE(ldo23_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "LDO3",
		.id = LP3972_LDO3,
		.ops = &lp3972_ldo_ops,
		.n_voltages = ARRAY_SIZE(ldo23_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "LDO4",
		.id = LP3972_LDO4,
		.ops = &lp3972_ldo_ops,
		.n_voltages = ARRAY_SIZE(ldo4_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "LDO5",
		.id = LP3972_LDO5,
		.ops = &lp3972_ldo_ops,
		.n_voltages = ARRAY_SIZE(ldo5_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "DCDC1",
		.id = LP3972_DCDC1,
		.ops = &lp3972_dcdc_ops,
		.n_voltages = ARRAY_SIZE(buck1_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "DCDC2",
		.id = LP3972_DCDC2,
		.ops = &lp3972_dcdc_ops,
		.n_voltages = ARRAY_SIZE(buck23_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
	{
		.name = "DCDC3",
		.id = LP3972_DCDC3,
		.ops = &lp3972_dcdc_ops,
		.n_voltages = ARRAY_SIZE(buck23_voltage_map),
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
	},
};

static int __devinit setup_regulators(struct lp3972 *lp3972,
	struct lp3972_platform_data *pdata)
{
	int i, err;

	lp3972->num_regulators = pdata->num_regulators;
	lp3972->rdev = kcalloc(pdata->num_regulators,
				sizeof(struct regulator_dev *), GFP_KERNEL);
	if (!lp3972->rdev) {
		err = -ENOMEM;
		goto err_nomem;
	}

	/* Instantiate the regulators */
	for (i = 0; i < pdata->num_regulators; i++) {
		struct lp3972_regulator_subdev *reg = &pdata->regulators[i];
		lp3972->rdev[i] = regulator_register(&regulators[reg->id],
					lp3972->dev, reg->initdata, lp3972);

		if (IS_ERR(lp3972->rdev[i])) {
			err = PTR_ERR(lp3972->rdev[i]);
			dev_err(lp3972->dev, "regulator init failed: %d\n",
				err);
			goto error;
		}
	}

	return 0;
error:
	while (--i >= 0)
		regulator_unregister(lp3972->rdev[i]);
	kfree(lp3972->rdev);
	lp3972->rdev = NULL;
err_nomem:
	return err;
}

static int __devinit lp3972_i2c_probe(struct i2c_client *i2c,
			    const struct i2c_device_id *id)
{
	struct lp3972 *lp3972;
	struct lp3972_platform_data *pdata = i2c->dev.platform_data;
	int ret;
	u16 val;

	if (!pdata) {
		dev_dbg(&i2c->dev, "No platform init data supplied\n");
		return -ENODEV;
	}

	lp3972 = kzalloc(sizeof(struct lp3972), GFP_KERNEL);
	if (!lp3972)
		return -ENOMEM;

	lp3972->i2c = i2c;
	lp3972->dev = &i2c->dev;

	mutex_init(&lp3972->io_lock);

	/* Detect LP3972 */
	ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);
	if (ret == 0 &&
		(val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {
		ret = -ENODEV;
		dev_err(&i2c->dev, "chip reported: val = 0x%x\n", val);
	}
	if (ret < 0) {
		dev_err(&i2c->dev, "failed to detect device. ret = %d\n", ret);
		goto err_detect;
	}

	ret = setup_regulators(lp3972, pdata);
	if (ret < 0)
		goto err_detect;

	i2c_set_clientdata(i2c, lp3972);
	return 0;

err_detect:
	kfree(lp3972);
	return ret;
}

static int __devexit lp3972_i2c_remove(struct i2c_client *i2c)
{
	struct lp3972 *lp3972 = i2c_get_clientdata(i2c);
	int i;

	for (i = 0; i < lp3972->num_regulators; i++)
		regulator_unregister(lp3972->rdev[i]);
	kfree(lp3972->rdev);
	kfree(lp3972);

	return 0;
}

static const struct i2c_device_id lp3972_i2c_id[] = {
	{ "lp3972", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);

static struct i2c_driver lp3972_i2c_driver = {
	.driver = {
		.name = "lp3972",
		.owner = THIS_MODULE,
	},
	.probe    = lp3972_i2c_probe,
	.remove   = __devexit_p(lp3972_i2c_remove),
	.id_table = lp3972_i2c_id,
};

static int __init lp3972_module_init(void)
{
	return i2c_add_driver(&lp3972_i2c_driver);
}
subsys_initcall(lp3972_module_init);

static void __exit lp3972_module_exit(void)
{
	i2c_del_driver(&lp3972_i2c_driver);
}
module_exit(lp3972_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
MODULE_DESCRIPTION("LP3972 PMIC driver");