1 /*
2 * max1586.c -- Voltage and current regulation for the Maxim 1586
3 *
4 * Copyright (C) 2008 Robert Jarzmik
5 *
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.
10 *
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.
15 *
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
19 */
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>
27
28 #define MAX1586_V3_MAX_VSEL 31
29 #define MAX1586_V6_MAX_VSEL 3
30
31 #define MAX1586_V3_MIN_UV 700000
32 #define MAX1586_V3_MAX_UV 1475000
33
34 #define MAX1586_V6_MIN_UV 0
35 #define MAX1586_V6_MAX_UV 3000000
36
37 #define I2C_V3_SELECT (0 << 5)
38 #define I2C_V6_SELECT (1 << 5)
39
40 struct max1586_data {
41 struct i2c_client *client;
42
43 /* min/max V3 voltage */
44 unsigned int min_uV;
45 unsigned int max_uV;
46
47 struct regulator_dev *rdev[0];
48 };
49
50 /*
51 * V3 voltage
52 * On I2C bus, sending a "x" byte to the max1586 means :
53 * set V3 to 0.700V + (x & 0x1f) * 0.025V
54 * This voltage can be increased by external resistors
55 * R24 and R25=100kOhm as described in the data sheet.
56 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
57 */
max1586_v3_calc_voltage(struct max1586_data * max1586,unsigned selector)58 static int max1586_v3_calc_voltage(struct max1586_data *max1586,
59 unsigned selector)
60 {
61 unsigned range_uV = max1586->max_uV - max1586->min_uV;
62
63 return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL);
64 }
65
max1586_v3_set(struct regulator_dev * rdev,int min_uV,int max_uV,unsigned * selector)66 static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV,
67 unsigned *selector)
68 {
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;
72 u8 v3_prog;
73
74 if (min_uV > max1586->max_uV || max_uV < max1586->min_uV)
75 return -EINVAL;
76 if (min_uV < max1586->min_uV)
77 min_uV = max1586->min_uV;
78
79 *selector = DIV_ROUND_UP((min_uV - max1586->min_uV) *
80 MAX1586_V3_MAX_VSEL, range_uV);
81 if (max1586_v3_calc_voltage(max1586, *selector) > max_uV)
82 return -EINVAL;
83
84 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
85 max1586_v3_calc_voltage(max1586, *selector) / 1000);
86
87 v3_prog = I2C_V3_SELECT | (u8) *selector;
88 return i2c_smbus_write_byte(client, v3_prog);
89 }
90
max1586_v3_list(struct regulator_dev * rdev,unsigned selector)91 static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector)
92 {
93 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
94
95 if (selector > MAX1586_V3_MAX_VSEL)
96 return -EINVAL;
97 return max1586_v3_calc_voltage(max1586, selector);
98 }
99
100 /*
101 * V6 voltage
102 * On I2C bus, sending a "x" byte to the max1586 means :
103 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
104 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
105 */
max1586_v6_calc_voltage(unsigned selector)106 static int max1586_v6_calc_voltage(unsigned selector)
107 {
108 static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
109
110 return voltages_uv[selector];
111 }
112
max1586_v6_set(struct regulator_dev * rdev,int min_uV,int max_uV,unsigned int * selector)113 static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV,
114 unsigned int *selector)
115 {
116 struct i2c_client *client = rdev_get_drvdata(rdev);
117 u8 v6_prog;
118
119 if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV)
120 return -EINVAL;
121 if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV)
122 return -EINVAL;
123
124 if (min_uV < 1800000)
125 *selector = 0;
126 else if (min_uV < 2500000)
127 *selector = 1;
128 else if (min_uV < 3000000)
129 *selector = 2;
130 else if (min_uV >= 3000000)
131 *selector = 3;
132
133 if (max1586_v6_calc_voltage(*selector) > max_uV)
134 return -EINVAL;
135
136 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
137 max1586_v6_calc_voltage(*selector) / 1000);
138
139 v6_prog = I2C_V6_SELECT | (u8) *selector;
140 return i2c_smbus_write_byte(client, v6_prog);
141 }
142
max1586_v6_list(struct regulator_dev * rdev,unsigned selector)143 static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector)
144 {
145 if (selector > MAX1586_V6_MAX_VSEL)
146 return -EINVAL;
147 return max1586_v6_calc_voltage(selector);
148 }
149
150 /*
151 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
152 * the set up value.
153 */
154 static struct regulator_ops max1586_v3_ops = {
155 .set_voltage = max1586_v3_set,
156 .list_voltage = max1586_v3_list,
157 };
158
159 static struct regulator_ops max1586_v6_ops = {
160 .set_voltage = max1586_v6_set,
161 .list_voltage = max1586_v6_list,
162 };
163
164 static struct regulator_desc max1586_reg[] = {
165 {
166 .name = "Output_V3",
167 .id = MAX1586_V3,
168 .ops = &max1586_v3_ops,
169 .type = REGULATOR_VOLTAGE,
170 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
171 .owner = THIS_MODULE,
172 },
173 {
174 .name = "Output_V6",
175 .id = MAX1586_V6,
176 .ops = &max1586_v6_ops,
177 .type = REGULATOR_VOLTAGE,
178 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
179 .owner = THIS_MODULE,
180 },
181 };
182
max1586_pmic_probe(struct i2c_client * client,const struct i2c_device_id * i2c_id)183 static int __devinit max1586_pmic_probe(struct i2c_client *client,
184 const struct i2c_device_id *i2c_id)
185 {
186 struct regulator_dev **rdev;
187 struct max1586_platform_data *pdata = client->dev.platform_data;
188 struct max1586_data *max1586;
189 int i, id, ret = -ENOMEM;
190
191 max1586 = kzalloc(sizeof(struct max1586_data) +
192 sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
193 GFP_KERNEL);
194 if (!max1586)
195 goto out;
196
197 max1586->client = client;
198
199 if (!pdata->v3_gain) {
200 ret = -EINVAL;
201 goto out_unmap;
202 }
203 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
204 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
205
206 rdev = max1586->rdev;
207 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
208 id = pdata->subdevs[i].id;
209 if (!pdata->subdevs[i].platform_data)
210 continue;
211 if (id < MAX1586_V3 || id > MAX1586_V6) {
212 dev_err(&client->dev, "invalid regulator id %d\n", id);
213 goto err;
214 }
215 rdev[i] = regulator_register(&max1586_reg[id], &client->dev,
216 pdata->subdevs[i].platform_data,
217 max1586, NULL);
218 if (IS_ERR(rdev[i])) {
219 ret = PTR_ERR(rdev[i]);
220 dev_err(&client->dev, "failed to register %s\n",
221 max1586_reg[id].name);
222 goto err;
223 }
224 }
225
226 i2c_set_clientdata(client, max1586);
227 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
228 return 0;
229
230 err:
231 while (--i >= 0)
232 regulator_unregister(rdev[i]);
233 out_unmap:
234 kfree(max1586);
235 out:
236 return ret;
237 }
238
max1586_pmic_remove(struct i2c_client * client)239 static int __devexit max1586_pmic_remove(struct i2c_client *client)
240 {
241 struct max1586_data *max1586 = i2c_get_clientdata(client);
242 int i;
243
244 for (i = 0; i <= MAX1586_V6; i++)
245 if (max1586->rdev[i])
246 regulator_unregister(max1586->rdev[i]);
247 kfree(max1586);
248
249 return 0;
250 }
251
252 static const struct i2c_device_id max1586_id[] = {
253 { "max1586", 0 },
254 { }
255 };
256 MODULE_DEVICE_TABLE(i2c, max1586_id);
257
258 static struct i2c_driver max1586_pmic_driver = {
259 .probe = max1586_pmic_probe,
260 .remove = __devexit_p(max1586_pmic_remove),
261 .driver = {
262 .name = "max1586",
263 .owner = THIS_MODULE,
264 },
265 .id_table = max1586_id,
266 };
267
max1586_pmic_init(void)268 static int __init max1586_pmic_init(void)
269 {
270 return i2c_add_driver(&max1586_pmic_driver);
271 }
272 subsys_initcall(max1586_pmic_init);
273
max1586_pmic_exit(void)274 static void __exit max1586_pmic_exit(void)
275 {
276 i2c_del_driver(&max1586_pmic_driver);
277 }
278 module_exit(max1586_pmic_exit);
279
280 /* Module information */
281 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
282 MODULE_AUTHOR("Robert Jarzmik");
283 MODULE_LICENSE("GPL");
284