summaryrefslogtreecommitdiff
path: root/drivers/regulator/max1586.c
blob: 2c082d3ef484614897fa5d510e30e63ed8362188 (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
/*
 * max1586.c  --  Voltage and current regulation for the Maxim 1586
 *
 * Copyright (C) 2008 Robert Jarzmik
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#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/max1586.h>

#define MAX1586_V3_MAX_VSEL 31
#define MAX1586_V6_MAX_VSEL 3

#define MAX1586_V3_MIN_UV   700000
#define MAX1586_V3_MAX_UV  1475000

#define MAX1586_V6_MIN_UV        0
#define MAX1586_V6_MAX_UV  3000000

#define I2C_V3_SELECT (0 << 5)
#define I2C_V6_SELECT (1 << 5)

struct max1586_data {
	struct i2c_client *client;

	/* min/max V3 voltage */
	unsigned int min_uV;
	unsigned int max_uV;

	struct regulator_dev *rdev[0];
};

/*
 * V3 voltage
 * On I2C bus, sending a "x" byte to the max1586 means :
 *   set V3 to 0.700V + (x & 0x1f) * 0.025V
 * This voltage can be increased by external resistors
 * R24 and R25=100kOhm as described in the data sheet.
 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
 */
static int max1586_v3_calc_voltage(struct max1586_data *max1586,
	unsigned selector)
{
	unsigned range_uV = max1586->max_uV - max1586->min_uV;

	return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL);
}

static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV)
{
	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
	struct i2c_client *client = max1586->client;
	unsigned range_uV = max1586->max_uV - max1586->min_uV;
	unsigned selector;
	u8 v3_prog;

	if (min_uV > max1586->max_uV || max_uV < max1586->min_uV)
		return -EINVAL;
	if (min_uV < max1586->min_uV)
		min_uV = max1586->min_uV;

	selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL +
			range_uV - 1) / range_uV;
	if (max1586_v3_calc_voltage(max1586, selector) > max_uV)
		return -EINVAL;

	dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
		max1586_v3_calc_voltage(max1586, selector) / 1000);

	v3_prog = I2C_V3_SELECT | (u8) selector;
	return i2c_smbus_write_byte(client, v3_prog);
}

static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector)
{
	struct max1586_data *max1586 = rdev_get_drvdata(rdev);

	if (selector > MAX1586_V3_MAX_VSEL)
		return -EINVAL;
	return max1586_v3_calc_voltage(max1586, selector);
}

/*
 * V6 voltage
 * On I2C bus, sending a "x" byte to the max1586 means :
 *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
 */
static int max1586_v6_calc_voltage(unsigned selector)
{
	static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 };

	return voltages_uv[selector];
}

static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV)
{
	struct i2c_client *client = rdev_get_drvdata(rdev);
	unsigned selector;
	u8 v6_prog;

	if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV)
		return -EINVAL;
	if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV)
		return -EINVAL;

	if (min_uV >= 3000000)
		selector = 3;
	if (min_uV < 3000000)
		selector = 2;
	if (min_uV < 2500000)
		selector = 1;
	if (min_uV < 1800000)
		selector = 0;

	if (max1586_v6_calc_voltage(selector) > max_uV)
		return -EINVAL;

	dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
		max1586_v6_calc_voltage(selector) / 1000);

	v6_prog = I2C_V6_SELECT | (u8) selector;
	return i2c_smbus_write_byte(client, v6_prog);
}

static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector)
{
	if (selector > MAX1586_V6_MAX_VSEL)
		return -EINVAL;
	return max1586_v6_calc_voltage(selector);
}

/*
 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
 * the set up value.
 */
static struct regulator_ops max1586_v3_ops = {
	.set_voltage = max1586_v3_set,
	.list_voltage = max1586_v3_list,
};

static struct regulator_ops max1586_v6_ops = {
	.set_voltage = max1586_v6_set,
	.list_voltage = max1586_v6_list,
};

static struct regulator_desc max1586_reg[] = {
	{
		.name = "Output_V3",
		.id = MAX1586_V3,
		.ops = &max1586_v3_ops,
		.type = REGULATOR_VOLTAGE,
		.n_voltages = MAX1586_V3_MAX_VSEL + 1,
		.owner = THIS_MODULE,
	},
	{
		.name = "Output_V6",
		.id = MAX1586_V6,
		.ops = &max1586_v6_ops,
		.type = REGULATOR_VOLTAGE,
		.n_voltages = MAX1586_V6_MAX_VSEL + 1,
		.owner = THIS_MODULE,
	},
};

static int max1586_pmic_probe(struct i2c_client *client,
			      const struct i2c_device_id *i2c_id)
{
	struct regulator_dev **rdev;
	struct max1586_platform_data *pdata = client->dev.platform_data;
	struct max1586_data *max1586;
	int i, id, ret = -ENOMEM;

	max1586 = kzalloc(sizeof(struct max1586_data) +
			sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
			GFP_KERNEL);
	if (!max1586)
		goto out;

	max1586->client = client;

	if (!pdata->v3_gain) {
		ret = -EINVAL;
		goto out_unmap;
	}
	max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
	max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;

	rdev = max1586->rdev;
	for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
		id = pdata->subdevs[i].id;
		if (!pdata->subdevs[i].platform_data)
			continue;
		if (id < MAX1586_V3 || id > MAX1586_V6) {
			dev_err(&client->dev, "invalid regulator id %d\n", id);
			goto err;
		}
		rdev[i] = regulator_register(&max1586_reg[id], &client->dev,
					     pdata->subdevs[i].platform_data,
					     max1586);
		if (IS_ERR(rdev[i])) {
			ret = PTR_ERR(rdev[i]);
			dev_err(&client->dev, "failed to register %s\n",
				max1586_reg[id].name);
			goto err;
		}
	}

	i2c_set_clientdata(client, rdev);
	dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
	return 0;

err:
	while (--i >= 0)
		regulator_unregister(rdev[i]);
out_unmap:
	kfree(max1586);
out:
	return ret;
}

static int max1586_pmic_remove(struct i2c_client *client)
{
	struct regulator_dev **rdev = i2c_get_clientdata(client);
	int i;

	for (i = 0; i <= MAX1586_V6; i++)
		if (rdev[i])
			regulator_unregister(rdev[i]);
	kfree(rdev);
	i2c_set_clientdata(client, NULL);

	return 0;
}

static const struct i2c_device_id max1586_id[] = {
	{ "max1586", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, max1586_id);

static struct i2c_driver max1586_pmic_driver = {
	.probe = max1586_pmic_probe,
	.remove = max1586_pmic_remove,
	.driver		= {
		.name	= "max1586",
	},
	.id_table	= max1586_id,
};

static int __init max1586_pmic_init(void)
{
	return i2c_add_driver(&max1586_pmic_driver);
}
subsys_initcall(max1586_pmic_init);

static void __exit max1586_pmic_exit(void)
{
	i2c_del_driver(&max1586_pmic_driver);
}
module_exit(max1586_pmic_exit);

/* Module information */
MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
MODULE_AUTHOR("Robert Jarzmik");
MODULE_LICENSE("GPL");