2 * max1586.c -- Voltage and current regulation for the Maxim 1586
4 * Copyright (C) 2008 Robert Jarzmik
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include <linux/module.h>
21 #include <linux/err.h>
22 #include <linux/i2c.h>
23 #include <linux/platform_device.h>
24 #include <linux/regulator/driver.h>
25 #include <linux/slab.h>
26 #include <linux/regulator/max1586.h>
28 #define MAX1586_V3_MAX_VSEL 31
29 #define MAX1586_V6_MAX_VSEL 3
31 #define MAX1586_V3_MIN_UV 700000
32 #define MAX1586_V3_MAX_UV 1475000
34 #define MAX1586_V6_MIN_UV 0
35 #define MAX1586_V6_MAX_UV 3000000
37 #define I2C_V3_SELECT (0 << 5)
38 #define I2C_V6_SELECT (1 << 5)
41 struct i2c_client *client;
43 /* min/max V3 voltage */
47 struct regulator_dev *rdev[0];
52 * On I2C bus, sending a "x" byte to the max1586 means :
53 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
54 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
56 static int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
60 * On I2C bus, sending a "x" byte to the max1586 means :
61 * set V3 to 0.700V + (x & 0x1f) * 0.025V
62 * This voltage can be increased by external resistors
63 * R24 and R25=100kOhm as described in the data sheet.
64 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
66 static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV,
69 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
70 struct i2c_client *client = max1586->client;
71 unsigned range_uV = max1586->max_uV - max1586->min_uV;
74 if (min_uV > max1586->max_uV || max_uV < max1586->min_uV)
76 if (min_uV < max1586->min_uV)
77 min_uV = max1586->min_uV;
79 *selector = DIV_ROUND_UP((min_uV - max1586->min_uV) *
80 MAX1586_V3_MAX_VSEL, range_uV);
81 if (regulator_list_voltage_linear(rdev, *selector) > max_uV)
84 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
85 regulator_list_voltage_linear(rdev, *selector) / 1000);
87 v3_prog = I2C_V3_SELECT | (u8) *selector;
88 return i2c_smbus_write_byte(client, v3_prog);
91 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
92 unsigned int selector)
94 struct i2c_client *client = rdev_get_drvdata(rdev);
97 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
98 rdev->desc->volt_table[selector] / 1000);
100 v6_prog = I2C_V6_SELECT | (u8) selector;
101 return i2c_smbus_write_byte(client, v6_prog);
105 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
108 static struct regulator_ops max1586_v3_ops = {
109 .set_voltage = max1586_v3_set,
110 .list_voltage = regulator_list_voltage_linear,
113 static struct regulator_ops max1586_v6_ops = {
114 .set_voltage_sel = max1586_v6_set_voltage_sel,
115 .list_voltage = regulator_list_voltage_table,
118 static struct regulator_desc max1586_reg[] = {
122 .ops = &max1586_v3_ops,
123 .type = REGULATOR_VOLTAGE,
124 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
125 .owner = THIS_MODULE,
130 .ops = &max1586_v6_ops,
131 .type = REGULATOR_VOLTAGE,
132 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
133 .volt_table = v6_voltages_uv,
134 .owner = THIS_MODULE,
138 static int __devinit max1586_pmic_probe(struct i2c_client *client,
139 const struct i2c_device_id *i2c_id)
141 struct regulator_dev **rdev;
142 struct max1586_platform_data *pdata = client->dev.platform_data;
143 struct regulator_config config = { };
144 struct max1586_data *max1586;
145 int i, id, ret = -ENOMEM;
147 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) +
148 sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
153 max1586->client = client;
158 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
159 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
161 rdev = max1586->rdev;
162 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
163 id = pdata->subdevs[i].id;
164 if (!pdata->subdevs[i].platform_data)
166 if (id < MAX1586_V3 || id > MAX1586_V6) {
167 dev_err(&client->dev, "invalid regulator id %d\n", id);
171 if (id == MAX1586_V3) {
172 max1586_reg[id].min_uV = max1586->min_uV;
173 max1586_reg[id].uV_step =
174 (max1586->max_uV - max1586->min_uV) /
178 config.dev = &client->dev;
179 config.init_data = pdata->subdevs[i].platform_data;
180 config.driver_data = max1586;
182 rdev[i] = regulator_register(&max1586_reg[id], &config);
183 if (IS_ERR(rdev[i])) {
184 ret = PTR_ERR(rdev[i]);
185 dev_err(&client->dev, "failed to register %s\n",
186 max1586_reg[id].name);
191 i2c_set_clientdata(client, max1586);
192 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
197 regulator_unregister(rdev[i]);
201 static int __devexit max1586_pmic_remove(struct i2c_client *client)
203 struct max1586_data *max1586 = i2c_get_clientdata(client);
206 for (i = 0; i <= MAX1586_V6; i++)
207 if (max1586->rdev[i])
208 regulator_unregister(max1586->rdev[i]);
212 static const struct i2c_device_id max1586_id[] = {
216 MODULE_DEVICE_TABLE(i2c, max1586_id);
218 static struct i2c_driver max1586_pmic_driver = {
219 .probe = max1586_pmic_probe,
220 .remove = __devexit_p(max1586_pmic_remove),
223 .owner = THIS_MODULE,
225 .id_table = max1586_id,
228 static int __init max1586_pmic_init(void)
230 return i2c_add_driver(&max1586_pmic_driver);
232 subsys_initcall(max1586_pmic_init);
234 static void __exit max1586_pmic_exit(void)
236 i2c_del_driver(&max1586_pmic_driver);
238 module_exit(max1586_pmic_exit);
240 /* Module information */
241 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
242 MODULE_AUTHOR("Robert Jarzmik");
243 MODULE_LICENSE("GPL");