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#include <linux/of_device.h>
28#include <linux/regulator/of_regulator.h>
29
30#define MAX1586_V3_MAX_VSEL 31
31#define MAX1586_V6_MAX_VSEL 3
32
33#define MAX1586_V3_MIN_UV 700000
34#define MAX1586_V3_MAX_UV 1475000
35
36#define MAX1586_V6_MIN_UV 0
37#define MAX1586_V6_MAX_UV 3000000
38
39#define I2C_V3_SELECT (0 << 5)
40#define I2C_V6_SELECT (1 << 5)
41
42struct max1586_data {
43 struct i2c_client *client;
44
45 /* min/max V3 voltage */
46 unsigned int min_uV;
47 unsigned int max_uV;
48
49 unsigned int v3_curr_sel;
50 unsigned int v6_curr_sel;
51};
52
53/*
54 * V6 voltage
55 * On I2C bus, sending a "x" byte to the max1586 means :
56 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
57 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
58 */
59static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
60
61/*
62 * V3 voltage
63 * On I2C bus, sending a "x" byte to the max1586 means :
64 * set V3 to 0.700V + (x & 0x1f) * 0.025V
65 * This voltage can be increased by external resistors
66 * R24 and R25=100kOhm as described in the data sheet.
67 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
68 */
69static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
70{
71 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
72
73 return max1586->v3_curr_sel;
74}
75
76static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
77 unsigned selector)
78{
79 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
80 struct i2c_client *client = max1586->client;
81 int ret;
82 u8 v3_prog;
83
84 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
85 regulator_list_voltage_linear(rdev, selector) / 1000);
86
87 v3_prog = I2C_V3_SELECT | (u8) selector;
88 ret = i2c_smbus_write_byte(client, v3_prog);
89 if (ret)
90 return ret;
91
92 max1586->v3_curr_sel = selector;
93
94 return 0;
95}
96
97static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
98{
99 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
100
101 return max1586->v6_curr_sel;
102}
103
104static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
105 unsigned int selector)
106{
107 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
108 struct i2c_client *client = max1586->client;
109 u8 v6_prog;
110 int ret;
111
112 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
113 rdev->desc->volt_table[selector] / 1000);
114
115 v6_prog = I2C_V6_SELECT | (u8) selector;
116 ret = i2c_smbus_write_byte(client, v6_prog);
117 if (ret)
118 return ret;
119
120 max1586->v6_curr_sel = selector;
121
122 return 0;
123}
124
125/*
126 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
127 * the set up value.
128 */
129static const struct regulator_ops max1586_v3_ops = {
130 .get_voltage_sel = max1586_v3_get_voltage_sel,
131 .set_voltage_sel = max1586_v3_set_voltage_sel,
132 .list_voltage = regulator_list_voltage_linear,
133 .map_voltage = regulator_map_voltage_linear,
134};
135
136static const struct regulator_ops max1586_v6_ops = {
137 .get_voltage_sel = max1586_v6_get_voltage_sel,
138 .set_voltage_sel = max1586_v6_set_voltage_sel,
139 .list_voltage = regulator_list_voltage_table,
140};
141
142static struct regulator_desc max1586_reg[] = {
143 {
144 .name = "Output_V3",
145 .id = MAX1586_V3,
146 .ops = &max1586_v3_ops,
147 .type = REGULATOR_VOLTAGE,
148 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
149 .owner = THIS_MODULE,
150 },
151 {
152 .name = "Output_V6",
153 .id = MAX1586_V6,
154 .ops = &max1586_v6_ops,
155 .type = REGULATOR_VOLTAGE,
156 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
157 .volt_table = v6_voltages_uv,
158 .owner = THIS_MODULE,
159 },
160};
161
162static int of_get_max1586_platform_data(struct device *dev,
163 struct max1586_platform_data *pdata)
164{
165 struct max1586_subdev_data *sub;
166 struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };
167 struct device_node *np = dev->of_node;
168 int i, matched;
169
170 if (of_property_read_u32(np, "v3-gain",
171 &pdata->v3_gain) < 0) {
172 dev_err(dev, "%pOF has no 'v3-gain' property\n", np);
173 return -EINVAL;
174 }
175
176 np = of_get_child_by_name(np, "regulators");
177 if (!np) {
178 dev_err(dev, "missing 'regulators' subnode in DT\n");
179 return -EINVAL;
180 }
181
182 for (i = 0; i < ARRAY_SIZE(rmatch); i++)
183 rmatch[i].name = max1586_reg[i].name;
184
185 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
186 of_node_put(np);
187 /*
188 * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,
189 * return 0, which signals the normal situation where no subregulator is
190 * available. This is normal because the max1586 doesn't provide any
191 * readback support, so the subregulators can't report any status
192 * anyway. If matched < 0, return the error.
193 */
194 if (matched <= 0)
195 return matched;
196
197 pdata->subdevs = devm_kcalloc(dev,
198 matched,
199 sizeof(struct max1586_subdev_data),
200 GFP_KERNEL);
201 if (!pdata->subdevs)
202 return -ENOMEM;
203
204 pdata->num_subdevs = matched;
205 sub = pdata->subdevs;
206
207 for (i = 0; i < matched; i++) {
208 sub->id = i;
209 sub->name = rmatch[i].of_node->name;
210 sub->platform_data = rmatch[i].init_data;
211 sub++;
212 }
213
214 return 0;
215}
216
217static const struct of_device_id max1586_of_match[] = {
218 { .compatible = "maxim,max1586", },
219 {},
220};
221MODULE_DEVICE_TABLE(of, max1586_of_match);
222
223static int max1586_pmic_probe(struct i2c_client *client,
224 const struct i2c_device_id *i2c_id)
225{
226 struct max1586_platform_data *pdata, pdata_of;
227 struct regulator_config config = { };
228 struct max1586_data *max1586;
229 int i, id, ret;
230 const struct of_device_id *match;
231
232 pdata = dev_get_platdata(&client->dev);
233 if (client->dev.of_node && !pdata) {
234 match = of_match_device(of_match_ptr(max1586_of_match),
235 &client->dev);
236 if (!match) {
237 dev_err(&client->dev, "Error: No device match found\n");
238 return -ENODEV;
239 }
240 ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
241 if (ret < 0)
242 return ret;
243 pdata = &pdata_of;
244 }
245
246 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
247 GFP_KERNEL);
248 if (!max1586)
249 return -ENOMEM;
250
251 max1586->client = client;
252
253 if (!pdata->v3_gain)
254 return -EINVAL;
255
256 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
257 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
258
259 /* Set curr_sel to default voltage on power-up */
260 max1586->v3_curr_sel = 24; /* 1.3V */
261 max1586->v6_curr_sel = 0;
262
263 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
264 struct regulator_dev *rdev;
265
266 id = pdata->subdevs[i].id;
267 if (!pdata->subdevs[i].platform_data)
268 continue;
269 if (id < MAX1586_V3 || id > MAX1586_V6) {
270 dev_err(&client->dev, "invalid regulator id %d\n", id);
271 return -EINVAL;
272 }
273
274 if (id == MAX1586_V3) {
275 max1586_reg[id].min_uV = max1586->min_uV;
276 max1586_reg[id].uV_step =
277 (max1586->max_uV - max1586->min_uV) /
278 MAX1586_V3_MAX_VSEL;
279 }
280
281 config.dev = &client->dev;
282 config.init_data = pdata->subdevs[i].platform_data;
283 config.driver_data = max1586;
284
285 rdev = devm_regulator_register(&client->dev,
286 &max1586_reg[id], &config);
287 if (IS_ERR(rdev)) {
288 dev_err(&client->dev, "failed to register %s\n",
289 max1586_reg[id].name);
290 return PTR_ERR(rdev);
291 }
292 }
293
294 i2c_set_clientdata(client, max1586);
295 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
296 return 0;
297}
298
299static const struct i2c_device_id max1586_id[] = {
300 { "max1586", 0 },
301 { }
302};
303MODULE_DEVICE_TABLE(i2c, max1586_id);
304
305static struct i2c_driver max1586_pmic_driver = {
306 .probe = max1586_pmic_probe,
307 .driver = {
308 .name = "max1586",
309 .of_match_table = of_match_ptr(max1586_of_match),
310 },
311 .id_table = max1586_id,
312};
313
314static int __init max1586_pmic_init(void)
315{
316 return i2c_add_driver(&max1586_pmic_driver);
317}
318subsys_initcall(max1586_pmic_init);
319
320static void __exit max1586_pmic_exit(void)
321{
322 i2c_del_driver(&max1586_pmic_driver);
323}
324module_exit(max1586_pmic_exit);
325
326/* Module information */
327MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
328MODULE_AUTHOR("Robert Jarzmik");
329MODULE_LICENSE("GPL");
330