aboutsummaryrefslogtreecommitdiff
path: root/drivers/regulator/ltc3676.c
blob: e12e52c69e52e9c13bfacf1d8f6cfd073488d05d (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2016 Gateworks Corporation, Inc. All Rights Reserved.
 */
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>

#define DRIVER_NAME		"ltc3676"

/* LTC3676 Registers */
#define LTC3676_BUCK1     0x01
#define LTC3676_BUCK2     0x02
#define LTC3676_BUCK3     0x03
#define LTC3676_BUCK4     0x04
#define LTC3676_LDOA      0x05
#define LTC3676_LDOB      0x06
#define LTC3676_SQD1      0x07
#define LTC3676_SQD2      0x08
#define LTC3676_CNTRL     0x09
#define LTC3676_DVB1A     0x0A
#define LTC3676_DVB1B     0x0B
#define LTC3676_DVB2A     0x0C
#define LTC3676_DVB2B     0x0D
#define LTC3676_DVB3A     0x0E
#define LTC3676_DVB3B     0x0F
#define LTC3676_DVB4A     0x10
#define LTC3676_DVB4B     0x11
#define LTC3676_MSKIRQ    0x12
#define LTC3676_MSKPG     0x13
#define LTC3676_USER      0x14
#define LTC3676_IRQSTAT   0x15
#define LTC3676_PGSTATL   0x16
#define LTC3676_PGSTATRT  0x17
#define LTC3676_HRST      0x1E
#define LTC3676_CLIRQ     0x1F

#define LTC3676_DVBxA_REF_SELECT	BIT(5)
#define LTC3676_DVBxB_PGOOD_MASK	BIT(5)

#define LTC3676_IRQSTAT_PGOOD_TIMEOUT	BIT(3)
#define LTC3676_IRQSTAT_UNDERVOLT_WARN	BIT(4)
#define LTC3676_IRQSTAT_UNDERVOLT_FAULT	BIT(5)
#define LTC3676_IRQSTAT_THERMAL_WARN	BIT(6)
#define LTC3676_IRQSTAT_THERMAL_FAULT	BIT(7)

enum ltc3676_reg {
	LTC3676_SW1,
	LTC3676_SW2,
	LTC3676_SW3,
	LTC3676_SW4,
	LTC3676_LDO1,
	LTC3676_LDO2,
	LTC3676_LDO3,
	LTC3676_LDO4,
	LTC3676_NUM_REGULATORS,
};

struct ltc3676 {
	struct regmap *regmap;
	struct device *dev;
	struct regulator_desc regulator_descs[LTC3676_NUM_REGULATORS];
	struct regulator_dev *regulators[LTC3676_NUM_REGULATORS];
};

static int ltc3676_set_suspend_voltage(struct regulator_dev *rdev, int uV)
{
	struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
	struct device *dev = ltc3676->dev;
	int dcdc = rdev_get_id(rdev);
	int sel;

	dev_dbg(dev, "%s id=%d uV=%d\n", __func__, dcdc, uV);
	sel = regulator_map_voltage_linear(rdev, uV, uV);
	if (sel < 0)
		return sel;

	/* DVBB register follows right after the corresponding DVBA register */
	return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
				  rdev->desc->vsel_mask, sel);
}

static int ltc3676_set_suspend_mode(struct regulator_dev *rdev,
				    unsigned int mode)
{
	struct ltc3676 *ltc3676= rdev_get_drvdata(rdev);
	struct device *dev = ltc3676->dev;
	int mask, val;
	int dcdc = rdev_get_id(rdev);

	dev_dbg(dev, "%s id=%d mode=%d\n", __func__, dcdc, mode);

	mask = LTC3676_DVBxA_REF_SELECT;
	switch (mode) {
	case REGULATOR_MODE_STANDBY:
		val = 0; /* select DVBxA */
		break;
	case REGULATOR_MODE_NORMAL:
		val = LTC3676_DVBxA_REF_SELECT; /* select DVBxB */
		break;
	default:
		dev_warn(&rdev->dev, "%s: regulator mode: 0x%x not supported\n",
			 rdev->desc->name, mode);
		return -EINVAL;
	}

	return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg,
				  mask, val);
}

static int ltc3676_set_voltage_sel(struct regulator_dev *rdev, unsigned selector)
{
	struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
	struct device *dev = ltc3676->dev;
	int ret, dcdc = rdev_get_id(rdev);

	dev_dbg(dev, "%s id=%d selector=%d\n", __func__, dcdc, selector);

	ret = regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
				 LTC3676_DVBxB_PGOOD_MASK,
				 LTC3676_DVBxB_PGOOD_MASK);
	if (ret)
		return ret;

	return regulator_set_voltage_sel_regmap(rdev, selector);
}

static inline unsigned int ltc3676_scale(unsigned int uV, u32 r1, u32 r2)
{
	uint64_t tmp;
	if (uV == 0)
		return 0;
	tmp = (uint64_t)uV * r1;
	do_div(tmp, r2);
	return uV + (unsigned int)tmp;
}

static int ltc3676_of_parse_cb(struct device_node *np,
			       const struct regulator_desc *desc,
			       struct regulator_config *config)
{
	struct ltc3676 *ltc3676 = config->driver_data;
	struct regulator_desc *rdesc = &ltc3676->regulator_descs[desc->id];
	u32 r[2];
	int ret;

	/* LDO3 has a fixed output */
	if (desc->id == LTC3676_LDO3)
		return 0;

	ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2);
	if (ret) {
		dev_err(ltc3676->dev, "Failed to parse voltage divider: %d\n",
			ret);
		return ret;
	}

	rdesc->min_uV = ltc3676_scale(desc->min_uV, r[0], r[1]);
	rdesc->uV_step = ltc3676_scale(desc->uV_step, r[0], r[1]);
	rdesc->fixed_uV = ltc3676_scale(desc->fixed_uV, r[0], r[1]);

	return 0;
}

/* SW1, SW2, SW3, SW4 linear 0.8V-3.3V with scalar via R1/R2 feeback res */
static const struct regulator_ops ltc3676_linear_regulator_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.set_voltage_sel = ltc3676_set_voltage_sel,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_suspend_voltage = ltc3676_set_suspend_voltage,
	.set_suspend_mode = ltc3676_set_suspend_mode,
};

/* LDO1 always on fixed 0.8V-3.3V via scalar via R1/R2 feeback res */
static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
};

/* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */
static const struct regulator_ops ltc3676_fixed_regulator_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
};

#define LTC3676_REG(_id, _name, _ops, en_reg, en_bit, dvba_reg, dvb_mask)   \
	[LTC3676_ ## _id] = {                                        \
		.name = #_name,                                \
		.of_match = of_match_ptr(#_name),              \
		.regulators_node = of_match_ptr("regulators"), \
		.of_parse_cb = ltc3676_of_parse_cb,            \
		.n_voltages = (dvb_mask) + 1,                  \
		.min_uV = (dvba_reg) ? 412500 : 0,             \
		.uV_step = (dvba_reg) ? 12500 : 0,             \
		.ramp_delay = (dvba_reg) ? 800 : 0,            \
		.fixed_uV = (dvb_mask) ? 0 : 725000,           \
		.ops = &ltc3676_ ## _ops ## _regulator_ops,    \
		.type = REGULATOR_VOLTAGE,                     \
		.id = LTC3676_ ## _id,                         \
		.owner = THIS_MODULE,                          \
		.vsel_reg = (dvba_reg),                        \
		.vsel_mask = (dvb_mask),                       \
		.enable_reg = (en_reg),                        \
		.enable_mask = (1 << en_bit),                  \
	}

#define LTC3676_LINEAR_REG(_id, _name, _en, _dvba)                     \
	LTC3676_REG(_id, _name, linear,                                \
		    LTC3676_ ## _en, 7,                                \
		    LTC3676_ ## _dvba, 0x1f)

#define LTC3676_FIXED_REG(_id, _name, _en_reg, _en_bit)                \
	LTC3676_REG(_id, _name, fixed, LTC3676_ ## _en_reg, _en_bit, 0, 0)

static struct regulator_desc ltc3676_regulators[LTC3676_NUM_REGULATORS] = {
	LTC3676_LINEAR_REG(SW1, sw1, BUCK1, DVB1A),
	LTC3676_LINEAR_REG(SW2, sw2, BUCK2, DVB2A),
	LTC3676_LINEAR_REG(SW3, sw3, BUCK3, DVB3A),
	LTC3676_LINEAR_REG(SW4, sw4, BUCK4, DVB4A),
	LTC3676_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0),
	LTC3676_FIXED_REG(LDO2, ldo2, LDOA, 2),
	LTC3676_FIXED_REG(LDO3, ldo3, LDOA, 5),
	LTC3676_FIXED_REG(LDO4, ldo4, LDOB, 2),
};

static bool ltc3676_readable_writeable_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case LTC3676_BUCK1 ... LTC3676_IRQSTAT:
	case LTC3676_HRST:
	case LTC3676_CLIRQ:
		return true;
	}
	return false;
}

static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case LTC3676_IRQSTAT ... LTC3676_PGSTATRT:
		return true;
	}
	return false;
}

static const struct regmap_config ltc3676_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.writeable_reg = ltc3676_readable_writeable_reg,
	.readable_reg = ltc3676_readable_writeable_reg,
	.volatile_reg = ltc3676_volatile_reg,
	.max_register = LTC3676_CLIRQ,
	.use_single_read = true,
	.use_single_write = true,
	.cache_type = REGCACHE_RBTREE,
};

static irqreturn_t ltc3676_isr(int irq, void *dev_id)
{
	struct ltc3676 *ltc3676 = dev_id;
	struct device *dev = ltc3676->dev;
	unsigned int i, irqstat, event;

	regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat);

	dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat);
	if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) {
		dev_warn(dev, "Over-temperature Warning\n");
		event = REGULATOR_EVENT_OVER_TEMP;
		for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
			regulator_lock(ltc3676->regulators[i]);
			regulator_notifier_call_chain(ltc3676->regulators[i],
						      event, NULL);
			regulator_unlock(ltc3676->regulators[i]);
		}
	}

	if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) {
		dev_info(dev, "Undervoltage Warning\n");
		event = REGULATOR_EVENT_UNDER_VOLTAGE;
		for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
			regulator_lock(ltc3676->regulators[i]);
			regulator_notifier_call_chain(ltc3676->regulators[i],
						      event, NULL);
			regulator_unlock(ltc3676->regulators[i]);
		}
	}

	/* Clear warning condition */
	regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);

	return IRQ_HANDLED;
}

static int ltc3676_regulator_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct regulator_init_data *init_data = dev_get_platdata(dev);
	struct regulator_desc *descs;
	struct ltc3676 *ltc3676;
	int i, ret;

	ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL);
	if (!ltc3676)
		return -ENOMEM;

	i2c_set_clientdata(client, ltc3676);
	ltc3676->dev = dev;

	descs = ltc3676->regulator_descs;
	memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators));
	descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */

	ltc3676->regmap = devm_regmap_init_i2c(client, &ltc3676_regmap_config);
	if (IS_ERR(ltc3676->regmap)) {
		ret = PTR_ERR(ltc3676->regmap);
		dev_err(dev, "failed to initialize regmap: %d\n", ret);
		return ret;
	}

	for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
		struct regulator_desc *desc = &ltc3676->regulator_descs[i];
		struct regulator_config config = { };

		if (init_data)
			config.init_data = &init_data[i];

		config.dev = dev;
		config.driver_data = ltc3676;

		ltc3676->regulators[i] = devm_regulator_register(dev, desc,
								 &config);
		if (IS_ERR(ltc3676->regulators[i])) {
			ret = PTR_ERR(ltc3676->regulators[i]);
			dev_err(dev, "failed to register regulator %s: %d\n",
				desc->name, ret);
			return ret;
		}
	}

	regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
	if (client->irq) {
		ret = devm_request_threaded_irq(dev, client->irq, NULL,
						ltc3676_isr,
						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
						client->name, ltc3676);
		if (ret) {
			dev_err(dev, "Failed to request IRQ: %d\n", ret);
			return ret;
		}
	}

	return 0;
}

static const struct i2c_device_id ltc3676_i2c_id[] = {
	{ "ltc3676" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id);

static const struct of_device_id ltc3676_of_match[] = {
	{ .compatible = "lltc,ltc3676" },
	{ },
};
MODULE_DEVICE_TABLE(of, ltc3676_of_match);

static struct i2c_driver ltc3676_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.of_match_table = of_match_ptr(ltc3676_of_match),
	},
	.probe_new = ltc3676_regulator_probe,
	.id_table = ltc3676_i2c_id,
};
module_i2c_driver(ltc3676_driver);

MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676");
MODULE_LICENSE("GPL v2");