summaryrefslogtreecommitdiff
path: root/drivers/regulator/mt6331-regulator.c
blob: 0059f88c6fd7e647b00466a6b7603cd3a9ce3ecb (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
// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2022 Collabora Ltd.
// Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
//
// Based on mt6323-regulator.c,
//     Copyright (c) 2016 MediaTek Inc.
//

#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/mfd/mt6331/registers.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/mt6331-regulator.h>
#include <linux/regulator/of_regulator.h>

#define MT6331_LDO_MODE_NORMAL	0
#define MT6331_LDO_MODE_LP	1

/*
 * MT6331 regulators information
 *
 * @desc: standard fields of regulator description.
 * @qi: Mask for query enable signal status of regulators
 * @vselon_reg: Register sections for hardware control mode of bucks
 * @vselctrl_reg: Register for controlling the buck control mode.
 * @vselctrl_mask: Mask for query buck's voltage control mode.
 * @status_reg: Register for regulator enable status where qi unavailable
 * @status_mask: Mask for querying regulator enable status
 */
struct mt6331_regulator_info {
	struct regulator_desc desc;
	u32 qi;
	u32 vselon_reg;
	u32 vselctrl_reg;
	u32 vselctrl_mask;
	u32 modeset_reg;
	u32 modeset_mask;
	u32 status_reg;
	u32 status_mask;
};

#define MT6331_BUCK(match, vreg, min, max, step, volt_ranges, enreg,	\
		vosel, vosel_mask, voselon, vosel_ctrl)			\
[MT6331_ID_##vreg] = {							\
	.desc = {							\
		.name = #vreg,						\
		.of_match = of_match_ptr(match),			\
		.ops = &mt6331_volt_range_ops,				\
		.type = REGULATOR_VOLTAGE,				\
		.id = MT6331_ID_##vreg,					\
		.owner = THIS_MODULE,					\
		.n_voltages = (max - min)/step + 1,			\
		.linear_ranges = volt_ranges,				\
		.n_linear_ranges = ARRAY_SIZE(volt_ranges),		\
		.vsel_reg = vosel,					\
		.vsel_mask = vosel_mask,				\
		.enable_reg = enreg,					\
		.enable_mask = BIT(0),					\
	},								\
	.qi = BIT(13),							\
	.vselon_reg = voselon,						\
	.vselctrl_reg = vosel_ctrl,					\
	.vselctrl_mask = BIT(1),					\
	.status_mask = 0,						\
}

#define MT6331_LDO_AO(match, vreg, ldo_volt_table, vosel, vosel_mask)	\
[MT6331_ID_##vreg] = {							\
	.desc = {							\
		.name = #vreg,						\
		.of_match = of_match_ptr(match),			\
		.ops = &mt6331_volt_table_ao_ops,			\
		.type = REGULATOR_VOLTAGE,				\
		.id = MT6331_ID_##vreg,					\
		.owner = THIS_MODULE,					\
		.n_voltages = ARRAY_SIZE(ldo_volt_table),		\
		.volt_table = ldo_volt_table,				\
		.vsel_reg = vosel,					\
		.vsel_mask = vosel_mask,				\
	},								\
}

#define MT6331_LDO_S(match, vreg, ldo_volt_table, enreg, enbit, vosel,	\
		     vosel_mask, _modeset_reg, _modeset_mask,		\
		     _status_reg, _status_mask)				\
[MT6331_ID_##vreg] = {							\
	.desc = {							\
		.name = #vreg,						\
		.of_match = of_match_ptr(match),			\
		.ops = &mt6331_volt_table_no_qi_ops,			\
		.type = REGULATOR_VOLTAGE,				\
		.id = MT6331_ID_##vreg,					\
		.owner = THIS_MODULE,					\
		.n_voltages = ARRAY_SIZE(ldo_volt_table),		\
		.volt_table = ldo_volt_table,				\
		.vsel_reg = vosel,					\
		.vsel_mask = vosel_mask,				\
		.enable_reg = enreg,					\
		.enable_mask = BIT(enbit),				\
	},								\
	.modeset_reg = _modeset_reg,					\
	.modeset_mask = _modeset_mask,					\
	.status_reg = _status_reg,					\
	.status_mask = _status_mask,					\
}

#define MT6331_LDO(match, vreg, ldo_volt_table, enreg, enbit, vosel,	\
		   vosel_mask, _modeset_reg, _modeset_mask)		\
[MT6331_ID_##vreg] = {							\
	.desc = {							\
		.name = #vreg,						\
		.of_match = of_match_ptr(match),			\
		.ops = (_modeset_reg ?					\
			&mt6331_volt_table_ops :			\
			&mt6331_volt_table_no_ms_ops),			\
		.type = REGULATOR_VOLTAGE,				\
		.id = MT6331_ID_##vreg,					\
		.owner = THIS_MODULE,					\
		.n_voltages = ARRAY_SIZE(ldo_volt_table),		\
		.volt_table = ldo_volt_table,				\
		.vsel_reg = vosel,					\
		.vsel_mask = vosel_mask,				\
		.enable_reg = enreg,					\
		.enable_mask = BIT(enbit),				\
	},								\
	.qi = BIT(15),							\
	.modeset_reg = _modeset_reg,					\
	.modeset_mask = _modeset_mask,					\
}

#define MT6331_REG_FIXED(match, vreg, enreg, enbit, qibit, volt,	\
			 _modeset_reg, _modeset_mask)			\
[MT6331_ID_##vreg] = {							\
	.desc = {							\
		.name = #vreg,						\
		.of_match = of_match_ptr(match),			\
		.ops = (_modeset_reg ?					\
			&mt6331_volt_fixed_ops :			\
			&mt6331_volt_fixed_no_ms_ops),			\
		.type = REGULATOR_VOLTAGE,				\
		.id = MT6331_ID_##vreg,					\
		.owner = THIS_MODULE,					\
		.n_voltages = 1,					\
		.enable_reg = enreg,					\
		.enable_mask = BIT(enbit),				\
		.min_uV = volt,						\
	},								\
	.qi = BIT(qibit),						\
	.modeset_reg = _modeset_reg,					\
	.modeset_mask = _modeset_mask,					\
}

static const struct linear_range buck_volt_range[] = {
	REGULATOR_LINEAR_RANGE(700000, 0, 0x7f, 6250),
};

static const unsigned int ldo_volt_table1[] = {
	2800000, 3000000, 0, 3200000
};

static const unsigned int ldo_volt_table2[] = {
	1500000, 1800000, 2500000, 2800000,
};

static const unsigned int ldo_volt_table3[] = {
	1200000, 1300000, 1500000, 1800000, 2000000, 2800000, 3000000, 3300000,
};

static const unsigned int ldo_volt_table4[] = {
	0, 0, 1700000, 1800000, 1860000, 2760000, 3000000, 3100000,
};

static const unsigned int ldo_volt_table5[] = {
	1800000, 3300000, 1800000, 3300000,
};

static const unsigned int ldo_volt_table6[] = {
	3000000, 3300000,
};

static const unsigned int ldo_volt_table7[] = {
	1200000, 1600000, 1700000, 1800000, 1900000, 2000000, 2100000, 2200000,
};

static const unsigned int ldo_volt_table8[] = {
	900000, 1000000, 1100000, 1220000, 1300000, 1500000, 1500000, 1500000,
};

static const unsigned int ldo_volt_table9[] = {
	1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000, 1300000,
};

static const unsigned int ldo_volt_table10[] = {
	1200000, 1300000, 1500000, 1800000,
};

static const unsigned int ldo_volt_table11[] = {
	1200000, 1300000, 1400000, 1500000, 1600000, 1700000, 1800000, 1800000,
};

static int mt6331_get_status(struct regulator_dev *rdev)
{
	struct mt6331_regulator_info *info = rdev_get_drvdata(rdev);
	u32 regval;
	int ret;

	ret = regmap_read(rdev->regmap, info->desc.enable_reg, &regval);
	if (ret != 0) {
		dev_err(&rdev->dev, "Failed to get enable reg: %d\n", ret);
		return ret;
	}

	return (regval & info->qi) ? REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;
}

static int mt6331_ldo_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
	struct mt6331_regulator_info *info = rdev_get_drvdata(rdev);
	int val;

	switch (mode) {
	case REGULATOR_MODE_STANDBY:
		val = MT6331_LDO_MODE_LP;
		break;
	case REGULATOR_MODE_NORMAL:
		val = MT6331_LDO_MODE_NORMAL;
		break;
	default:
		return -EINVAL;
	}

	val <<= ffs(info->modeset_mask) - 1;

	return regmap_update_bits(rdev->regmap, info->modeset_reg,
				  info->modeset_mask, val);
}

static unsigned int mt6331_ldo_get_mode(struct regulator_dev *rdev)
{
	struct mt6331_regulator_info *info = rdev_get_drvdata(rdev);
	unsigned int val;
	int ret;

	ret = regmap_read(rdev->regmap, info->modeset_reg, &val);
	if (ret < 0)
		return ret;

	val &= info->modeset_mask;
	val >>= ffs(info->modeset_mask) - 1;

	return (val & BIT(0)) ? REGULATOR_MODE_STANDBY : REGULATOR_MODE_NORMAL;
}

static const struct regulator_ops mt6331_volt_range_ops = {
	.list_voltage = regulator_list_voltage_linear_range,
	.map_voltage = regulator_map_voltage_linear_range,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.get_status = mt6331_get_status,
};

static const struct regulator_ops mt6331_volt_table_no_ms_ops = {
	.list_voltage = regulator_list_voltage_table,
	.map_voltage = regulator_map_voltage_iterate,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.get_status = mt6331_get_status,
};

static const struct regulator_ops mt6331_volt_table_no_qi_ops = {
	.list_voltage = regulator_list_voltage_table,
	.map_voltage = regulator_map_voltage_iterate,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.set_mode = mt6331_ldo_set_mode,
	.get_mode = mt6331_ldo_get_mode,
};

static const struct regulator_ops mt6331_volt_table_ops = {
	.list_voltage = regulator_list_voltage_table,
	.map_voltage = regulator_map_voltage_iterate,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.get_status = mt6331_get_status,
	.set_mode = mt6331_ldo_set_mode,
	.get_mode = mt6331_ldo_get_mode,
};

static const struct regulator_ops mt6331_volt_table_ao_ops = {
	.list_voltage = regulator_list_voltage_table,
	.map_voltage = regulator_map_voltage_iterate,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
};

static const struct regulator_ops mt6331_volt_fixed_no_ms_ops = {
	.list_voltage = regulator_list_voltage_linear,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.get_status = mt6331_get_status,
};

static const struct regulator_ops mt6331_volt_fixed_ops = {
	.list_voltage = regulator_list_voltage_linear,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.get_status = mt6331_get_status,
	.set_mode = mt6331_ldo_set_mode,
	.get_mode = mt6331_ldo_get_mode,
};

/* The array is indexed by id(MT6331_ID_XXX) */
static struct mt6331_regulator_info mt6331_regulators[] = {
	MT6331_BUCK("buck-vdvfs11", VDVFS11, 700000, 1493750, 6250,
		    buck_volt_range, MT6331_VDVFS11_CON9,
		    MT6331_VDVFS11_CON11, GENMASK(6, 0),
		    MT6331_VDVFS11_CON12, MT6331_VDVFS11_CON7),
	MT6331_BUCK("buck-vdvfs12", VDVFS12, 700000, 1493750, 6250,
		    buck_volt_range, MT6331_VDVFS12_CON9,
		    MT6331_VDVFS12_CON11, GENMASK(6, 0),
		    MT6331_VDVFS12_CON12, MT6331_VDVFS12_CON7),
	MT6331_BUCK("buck-vdvfs13", VDVFS13, 700000, 1493750, 6250,
		    buck_volt_range, MT6331_VDVFS13_CON9,
		    MT6331_VDVFS13_CON11, GENMASK(6, 0),
		    MT6331_VDVFS13_CON12, MT6331_VDVFS13_CON7),
	MT6331_BUCK("buck-vdvfs14", VDVFS14, 700000, 1493750, 6250,
		    buck_volt_range, MT6331_VDVFS14_CON9,
		    MT6331_VDVFS14_CON11, GENMASK(6, 0),
		    MT6331_VDVFS14_CON12, MT6331_VDVFS14_CON7),
	MT6331_BUCK("buck-vcore2", VCORE2, 700000, 1493750, 6250,
		    buck_volt_range, MT6331_VCORE2_CON9,
		    MT6331_VCORE2_CON11, GENMASK(6, 0),
		    MT6331_VCORE2_CON12, MT6331_VCORE2_CON7),
	MT6331_REG_FIXED("buck-vio18", VIO18, MT6331_VIO18_CON9, 0, 13, 1800000, 0, 0),
	MT6331_REG_FIXED("ldo-vrtc", VRTC, MT6331_DIGLDO_CON11, 8, 15, 2800000, 0, 0),
	MT6331_REG_FIXED("ldo-vtcxo1", VTCXO1, MT6331_ANALDO_CON1, 10, 15, 2800000,
			 MT6331_ANALDO_CON1, GENMASK(1, 0)),
	MT6331_REG_FIXED("ldo-vtcxo2", VTCXO2, MT6331_ANALDO_CON2, 10, 15, 2800000,
			 MT6331_ANALDO_CON2, GENMASK(1, 0)),
	MT6331_REG_FIXED("ldo-vsram", VSRAM_DVFS1, MT6331_SYSLDO_CON4, 10, 15, 1012500,
			 MT6331_SYSLDO_CON4, GENMASK(1, 0)),
	MT6331_REG_FIXED("ldo-vio28", VIO28, MT6331_DIGLDO_CON1, 10, 15, 2800000,
			 MT6331_DIGLDO_CON1, GENMASK(1, 0)),
	MT6331_LDO("ldo-avdd32aud", AVDD32_AUD, ldo_volt_table1, MT6331_ANALDO_CON3, 10,
		   MT6331_ANALDO_CON10, GENMASK(6, 5), MT6331_ANALDO_CON3, GENMASK(1, 0)),
	MT6331_LDO("ldo-vauxa32", VAUXA32, ldo_volt_table1, MT6331_ANALDO_CON4, 10,
		   MT6331_ANALDO_CON6, GENMASK(6, 5), MT6331_ANALDO_CON4, GENMASK(1, 0)),
	MT6331_LDO("ldo-vemc33", VEMC33, ldo_volt_table6, MT6331_DIGLDO_CON5, 10,
		   MT6331_DIGLDO_CON17, BIT(6), MT6331_DIGLDO_CON5, GENMASK(1, 0)),
	MT6331_LDO("ldo-vibr", VIBR, ldo_volt_table3, MT6331_DIGLDO_CON12, 10,
		   MT6331_DIGLDO_CON20, GENMASK(6, 4), MT6331_DIGLDO_CON12, GENMASK(1, 0)),
	MT6331_LDO("ldo-vmc", VMC, ldo_volt_table5, MT6331_DIGLDO_CON3, 10,
		   MT6331_DIGLDO_CON15, GENMASK(5, 4), MT6331_DIGLDO_CON3, GENMASK(1, 0)),
	MT6331_LDO("ldo-vmch", VMCH, ldo_volt_table6, MT6331_DIGLDO_CON4, 10,
		   MT6331_DIGLDO_CON16, BIT(6), MT6331_DIGLDO_CON4, GENMASK(1, 0)),
	MT6331_LDO("ldo-vmipi", VMIPI, ldo_volt_table3, MT6331_SYSLDO_CON5, 10,
		   MT6331_SYSLDO_CON13, GENMASK(5, 3), MT6331_SYSLDO_CON5, GENMASK(1, 0)),
	MT6331_LDO("ldo-vsim1", VSIM1, ldo_volt_table4, MT6331_DIGLDO_CON8, 10,
		   MT6331_DIGLDO_CON21, GENMASK(6, 4), MT6331_DIGLDO_CON8, GENMASK(1, 0)),
	MT6331_LDO("ldo-vsim2", VSIM2, ldo_volt_table4, MT6331_DIGLDO_CON9, 10,
		   MT6331_DIGLDO_CON22, GENMASK(6, 4), MT6331_DIGLDO_CON9, GENMASK(1, 0)),
	MT6331_LDO("ldo-vusb10", VUSB10, ldo_volt_table9, MT6331_SYSLDO_CON2, 10,
		   MT6331_SYSLDO_CON10, GENMASK(5, 3), MT6331_SYSLDO_CON2, GENMASK(1, 0)),
	MT6331_LDO("ldo-vcama", VCAMA, ldo_volt_table2, MT6331_ANALDO_CON5, 15,
		   MT6331_ANALDO_CON9, GENMASK(5, 4), 0, 0),
	MT6331_LDO_S("ldo-vcamaf", VCAM_AF, ldo_volt_table3, MT6331_DIGLDO_CON2, 10,
		     MT6331_DIGLDO_CON14, GENMASK(6, 4), MT6331_DIGLDO_CON2, GENMASK(1, 0),
		     MT6331_EN_STATUS1, BIT(0)),
	MT6331_LDO_S("ldo-vcamd", VCAMD, ldo_volt_table8, MT6331_SYSLDO_CON1, 15,
		     MT6331_SYSLDO_CON9, GENMASK(6, 4), MT6331_SYSLDO_CON1, GENMASK(1, 0),
		     MT6331_EN_STATUS1, BIT(11)),
	MT6331_LDO_S("ldo-vcamio", VCAM_IO,  ldo_volt_table10, MT6331_SYSLDO_CON3, 10,
		     MT6331_SYSLDO_CON11, GENMASK(4, 3), MT6331_SYSLDO_CON3, GENMASK(1, 0),
		     MT6331_EN_STATUS1, BIT(13)),
	MT6331_LDO_S("ldo-vgp1", VGP1, ldo_volt_table3, MT6331_DIGLDO_CON6, 10,
		     MT6331_DIGLDO_CON19, GENMASK(6, 4), MT6331_DIGLDO_CON6, GENMASK(1, 0),
		     MT6331_EN_STATUS1, BIT(4)),
	MT6331_LDO_S("ldo-vgp2", VGP2, ldo_volt_table10, MT6331_SYSLDO_CON6, 10,
		     MT6331_SYSLDO_CON14, GENMASK(4, 3), MT6331_SYSLDO_CON6, GENMASK(1, 0),
		     MT6331_EN_STATUS1, BIT(15)),
	MT6331_LDO_S("ldo-vgp3", VGP3, ldo_volt_table10, MT6331_SYSLDO_CON7, 10,
		     MT6331_SYSLDO_CON15, GENMASK(4, 3), MT6331_SYSLDO_CON7, GENMASK(1, 0),
		     MT6331_EN_STATUS2, BIT(0)),
	MT6331_LDO_S("ldo-vgp4", VGP4, ldo_volt_table7, MT6331_DIGLDO_CON7, 10,
		     MT6331_DIGLDO_CON18, GENMASK(6, 4), MT6331_DIGLDO_CON7, GENMASK(1, 0),
		     MT6331_EN_STATUS1, BIT(5)),
	MT6331_LDO_AO("ldo-vdig18", VDIG18, ldo_volt_table11,
		      MT6331_DIGLDO_CON28, GENMASK(14, 12)),
};

static int mt6331_set_buck_vosel_reg(struct platform_device *pdev)
{
	struct mt6397_chip *mt6331 = dev_get_drvdata(pdev->dev.parent);
	int i;
	u32 regval;

	for (i = 0; i < MT6331_ID_VREG_MAX; i++) {
		if (mt6331_regulators[i].vselctrl_reg) {
			if (regmap_read(mt6331->regmap,
				mt6331_regulators[i].vselctrl_reg,
				&regval) < 0) {
				dev_err(&pdev->dev,
					"Failed to read buck ctrl\n");
				return -EIO;
			}

			if (regval & mt6331_regulators[i].vselctrl_mask) {
				mt6331_regulators[i].desc.vsel_reg =
				mt6331_regulators[i].vselon_reg;
			}
		}
	}

	return 0;
}

static int mt6331_regulator_probe(struct platform_device *pdev)
{
	struct mt6397_chip *mt6331 = dev_get_drvdata(pdev->dev.parent);
	struct regulator_config config = {};
	struct regulator_dev *rdev;
	int i;
	u32 reg_value;

	/* Query buck controller to select activated voltage register part */
	if (mt6331_set_buck_vosel_reg(pdev))
		return -EIO;

	/* Read PMIC chip revision to update constraints and voltage table */
	if (regmap_read(mt6331->regmap, MT6331_HWCID, &reg_value) < 0) {
		dev_err(&pdev->dev, "Failed to read Chip ID\n");
		return -EIO;
	}
	reg_value &= GENMASK(7, 0);

	dev_info(&pdev->dev, "Chip ID = 0x%x\n", reg_value);

	/*
	 * ChipID 0x10 is "MT6331 E1", has a different voltage table and
	 * it's currently not supported in this driver. Upon detection of
	 * this ID, refuse to register the regulators, as we will wrongly
	 * interpret the VSEL for this revision, potentially overvolting
	 * some device.
	 */
	if (reg_value == 0x10) {
		dev_err(&pdev->dev, "Chip version not supported. Bailing out.\n");
		return -EINVAL;
	}

	for (i = 0; i < MT6331_ID_VREG_MAX; i++) {
		config.dev = &pdev->dev;
		config.driver_data = &mt6331_regulators[i];
		config.regmap = mt6331->regmap;
		rdev = devm_regulator_register(&pdev->dev,
				&mt6331_regulators[i].desc, &config);
		if (IS_ERR(rdev)) {
			dev_err(&pdev->dev, "failed to register %s\n",
				mt6331_regulators[i].desc.name);
			return PTR_ERR(rdev);
		}
	}
	return 0;
}

static const struct platform_device_id mt6331_platform_ids[] = {
	{"mt6331-regulator", 0},
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, mt6331_platform_ids);

static struct platform_driver mt6331_regulator_driver = {
	.driver = {
		.name = "mt6331-regulator",
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
	.probe = mt6331_regulator_probe,
	.id_table = mt6331_platform_ids,
};

module_platform_driver(mt6331_regulator_driver);

MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
MODULE_DESCRIPTION("Regulator Driver for MediaTek MT6331 PMIC");
MODULE_LICENSE("GPL");