summaryrefslogtreecommitdiffstats
path: root/drivers/regulator/max8649.c
blob: 3ebdf698c648f6cb588a0637cbcd15ab6782f3e3 (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
/*
 * Regulators driver for Maxim max8649
 *
 * Copyright (C) 2009-2010 Marvell International Ltd.
 *      Haojian Zhuang <haojian.zhuang@marvell.com>
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/max8649.h>

#define MAX8649_DCDC_VMIN	750000		/* uV */
#define MAX8649_DCDC_VMAX	1380000		/* uV */
#define MAX8649_DCDC_STEP	10000		/* uV */
#define MAX8649_VOL_MASK	0x3f

/* Registers */
#define MAX8649_MODE0		0x00
#define MAX8649_MODE1		0x01
#define MAX8649_MODE2		0x02
#define MAX8649_MODE3		0x03
#define MAX8649_CONTROL		0x04
#define MAX8649_SYNC		0x05
#define MAX8649_RAMP		0x06
#define MAX8649_CHIP_ID1	0x08
#define MAX8649_CHIP_ID2	0x09

/* Bits */
#define MAX8649_EN_PD		(1 << 7)
#define MAX8649_VID0_PD		(1 << 6)
#define MAX8649_VID1_PD		(1 << 5)
#define MAX8649_VID_MASK	(3 << 5)

#define MAX8649_FORCE_PWM	(1 << 7)
#define MAX8649_SYNC_EXTCLK	(1 << 6)

#define MAX8649_EXT_MASK	(3 << 6)

#define MAX8649_RAMP_MASK	(7 << 5)
#define MAX8649_RAMP_DOWN	(1 << 1)

struct max8649_regulator_info {
	struct regulator_dev	*regulator;
	struct i2c_client	*i2c;
	struct device		*dev;
	struct mutex		io_lock;

	int		vol_reg;
	unsigned	mode:2;	/* bit[1:0] = VID1, VID0 */
	unsigned	extclk_freq:2;
	unsigned	extclk:1;
	unsigned	ramp_timing:3;
	unsigned	ramp_down:1;
};

/* I2C operations */

static inline int max8649_read_device(struct i2c_client *i2c,
				      int reg, int bytes, void *dest)
{
	unsigned char data;
	int ret;

	data = (unsigned char)reg;
	ret = i2c_master_send(i2c, &data, 1);
	if (ret < 0)
		return ret;
	ret = i2c_master_recv(i2c, dest, bytes);
	if (ret < 0)
		return ret;
	return 0;
}

static inline int max8649_write_device(struct i2c_client *i2c,
				       int reg, int bytes, void *src)
{
	unsigned char buf[bytes + 1];
	int ret;

	buf[0] = (unsigned char)reg;
	memcpy(&buf[1], src, bytes);

	ret = i2c_master_send(i2c, buf, bytes + 1);
	if (ret < 0)
		return ret;
	return 0;
}

static int max8649_reg_read(struct i2c_client *i2c, int reg)
{
	struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
	unsigned char data;
	int ret;

	mutex_lock(&info->io_lock);
	ret = max8649_read_device(i2c, reg, 1, &data);
	mutex_unlock(&info->io_lock);

	if (ret < 0)
		return ret;
	return (int)data;
}

static int max8649_set_bits(struct i2c_client *i2c, int reg,
			    unsigned char mask, unsigned char data)
{
	struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
	unsigned char value;
	int ret;

	mutex_lock(&info->io_lock);
	ret = max8649_read_device(i2c, reg, 1, &value);
	if (ret < 0)
		goto out;
	value &= ~mask;
	value |= data;
	ret = max8649_write_device(i2c, reg, 1, &value);
out:
	mutex_unlock(&info->io_lock);
	return ret;
}

static inline int check_range(int min_uV, int max_uV)
{
	if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
		|| (min_uV > max_uV))
		return -EINVAL;
	return 0;
}

static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
{
	return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
}

static int max8649_get_voltage(struct regulator_dev *rdev)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	unsigned char data;
	int ret;

	ret = max8649_reg_read(info->i2c, info->vol_reg);
	if (ret < 0)
		return ret;
	data = (unsigned char)ret & MAX8649_VOL_MASK;
	return max8649_list_voltage(rdev, data);
}

static int max8649_set_voltage(struct regulator_dev *rdev,
			       int min_uV, int max_uV)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	unsigned char data, mask;

	if (check_range(min_uV, max_uV)) {
		dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
			min_uV, max_uV);
		return -EINVAL;
	}
	data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1)
		/ MAX8649_DCDC_STEP;
	mask = MAX8649_VOL_MASK;

	return max8649_set_bits(info->i2c, info->vol_reg, mask, data);
}

/* EN_PD means pulldown on EN input */
static int max8649_enable(struct regulator_dev *rdev)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0);
}

/*
 * Applied internal pulldown resistor on EN input pin.
 * If pulldown EN pin outside, it would be better.
 */
static int max8649_disable(struct regulator_dev *rdev)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD,
				MAX8649_EN_PD);
}

static int max8649_is_enabled(struct regulator_dev *rdev)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	int ret;

	ret = max8649_reg_read(info->i2c, MAX8649_CONTROL);
	if (ret < 0)
		return ret;
	return !((unsigned char)ret & MAX8649_EN_PD);
}

static int max8649_enable_time(struct regulator_dev *rdev)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	int voltage, rate, ret;

	/* get voltage */
	ret = max8649_reg_read(info->i2c, info->vol_reg);
	if (ret < 0)
		return ret;
	ret &= MAX8649_VOL_MASK;
	voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */

	/* get rate */
	ret = max8649_reg_read(info->i2c, MAX8649_RAMP);
	if (ret < 0)
		return ret;
	ret = (ret & MAX8649_RAMP_MASK) >> 5;
	rate = (32 * 1000) >> ret;	/* uV/uS */

	return (voltage / rate);
}

static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);

	switch (mode) {
	case REGULATOR_MODE_FAST:
		max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM,
				 MAX8649_FORCE_PWM);
		break;
	case REGULATOR_MODE_NORMAL:
		max8649_set_bits(info->i2c, info->vol_reg,
				 MAX8649_FORCE_PWM, 0);
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static unsigned int max8649_get_mode(struct regulator_dev *rdev)
{
	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
	int ret;

	ret = max8649_reg_read(info->i2c, info->vol_reg);
	if (ret & MAX8649_FORCE_PWM)
		return REGULATOR_MODE_FAST;
	return REGULATOR_MODE_NORMAL;
}

static struct regulator_ops max8649_dcdc_ops = {
	.set_voltage	= max8649_set_voltage,
	.get_voltage	= max8649_get_voltage,
	.list_voltage	= max8649_list_voltage,
	.enable		= max8649_enable,
	.disable	= max8649_disable,
	.is_enabled	= max8649_is_enabled,
	.enable_time	= max8649_enable_time,
	.set_mode	= max8649_set_mode,
	.get_mode	= max8649_get_mode,

};

static struct regulator_desc dcdc_desc = {
	.name		= "max8649",
	.ops		= &max8649_dcdc_ops,
	.type		= REGULATOR_VOLTAGE,
	.n_voltages	= 1 << 6,
	.owner		= THIS_MODULE,
};

static int __devinit max8649_regulator_probe(struct i2c_client *client,
					     const struct i2c_device_id *id)
{
	struct max8649_platform_data *pdata = client->dev.platform_data;
	struct max8649_regulator_info *info = NULL;
	unsigned char data;
	int ret;

	info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
	if (!info) {
		dev_err(&client->dev, "No enough memory\n");
		return -ENOMEM;
	}

	info->i2c = client;
	info->dev = &client->dev;
	mutex_init(&info->io_lock);
	i2c_set_clientdata(client, info);

	info->mode = pdata->mode;
	switch (info->mode) {
	case 0:
		info->vol_reg = MAX8649_MODE0;
		break;
	case 1:
		info->vol_reg = MAX8649_MODE1;
		break;
	case 2:
		info->vol_reg = MAX8649_MODE2;
		break;
	case 3:
		info->vol_reg = MAX8649_MODE3;
		break;
	default:
		break;
	}

	ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1);
	if (ret < 0) {
		dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
			ret);
		goto out;
	}
	dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret);

	/* enable VID0 & VID1 */
	max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0);

	/* enable/disable external clock synchronization */
	info->extclk = pdata->extclk;
	data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
	max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
	if (info->extclk) {
		/* set external clock frequency */
		info->extclk_freq = pdata->extclk_freq;
		max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK,
				 info->extclk_freq);
	}

	if (pdata->ramp_timing) {
		info->ramp_timing = pdata->ramp_timing;
		max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK,
				 info->ramp_timing << 5);
	}

	info->ramp_down = pdata->ramp_down;
	if (info->ramp_down) {
		max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN,
				 MAX8649_RAMP_DOWN);
	}

	info->regulator = regulator_register(&dcdc_desc, &client->dev,
					     pdata->regulator, info);
	if (IS_ERR(info->regulator)) {
		dev_err(info->dev, "failed to register regulator %s\n",
			dcdc_desc.name);
		ret = PTR_ERR(info->regulator);
		goto out;
	}

	dev_info(info->dev, "Max8649 regulator device is detected.\n");
	return 0;
out:
	kfree(info);
	return ret;
}

static int __devexit max8649_regulator_remove(struct i2c_client *client)
{
	struct max8649_regulator_info *info = i2c_get_clientdata(client);

	if (info) {
		if (info->regulator)
			regulator_unregister(info->regulator);
		kfree(info);
	}
	i2c_set_clientdata(client, NULL);

	return 0;
}

static const struct i2c_device_id max8649_id[] = {
	{ "max8649", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, max8649_id);

static struct i2c_driver max8649_driver = {
	.probe		= max8649_regulator_probe,
	.remove		= __devexit_p(max8649_regulator_remove),
	.driver		= {
		.name	= "max8649",
	},
	.id_table	= max8649_id,
};

static int __init max8649_init(void)
{
	return i2c_add_driver(&max8649_driver);
}
subsys_initcall(max8649_init);

static void __exit max8649_exit(void)
{
	i2c_del_driver(&max8649_driver);
}
module_exit(max8649_exit);

/* Module information */
MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");

OpenPOWER on IntegriCloud