blob: 46d05f38baf8ee9bbc1cf9b7e1cd80c59651fafe [file] [log] [blame]
Sonic Zhang8b385d92010-06-04 11:46:04 +08001/*
2 * Voltage and current regulation for AD5398 and AD5821
3 *
4 * Copyright 2010 Analog Devices Inc.
5 *
6 * Enter bugs at http://blackfin.uclinux.org/
7 *
8 * Licensed under the GPL-2 or later.
9 */
10
11#include <linux/module.h>
12#include <linux/err.h>
13#include <linux/i2c.h>
14#include <linux/slab.h>
15#include <linux/platform_device.h>
16#include <linux/regulator/driver.h>
17#include <linux/regulator/machine.h>
18
19#define AD5398_CURRENT_EN_MASK 0x8000
20
21struct ad5398_chip_info {
22 struct i2c_client *client;
23 int min_uA;
24 int max_uA;
25 unsigned int current_level;
26 unsigned int current_mask;
27 unsigned int current_offset;
Axel Lin58d463e2010-09-01 10:29:18 +080028 struct regulator_dev *rdev;
Sonic Zhang8b385d92010-06-04 11:46:04 +080029};
30
31static int ad5398_calc_current(struct ad5398_chip_info *chip,
32 unsigned selector)
33{
34 unsigned range_uA = chip->max_uA - chip->min_uA;
35
36 return chip->min_uA + (selector * range_uA / chip->current_level);
37}
38
39static int ad5398_read_reg(struct i2c_client *client, unsigned short *data)
40{
41 unsigned short val;
42 int ret;
43
44 ret = i2c_master_recv(client, (char *)&val, 2);
45 if (ret < 0) {
46 dev_err(&client->dev, "I2C read error\n");
47 return ret;
48 }
49 *data = be16_to_cpu(val);
50
51 return ret;
52}
53
54static int ad5398_write_reg(struct i2c_client *client, const unsigned short data)
55{
56 unsigned short val;
57 int ret;
58
59 val = cpu_to_be16(data);
60 ret = i2c_master_send(client, (char *)&val, 2);
61 if (ret < 0)
62 dev_err(&client->dev, "I2C write error\n");
63
64 return ret;
65}
66
67static int ad5398_get_current_limit(struct regulator_dev *rdev)
68{
69 struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
70 struct i2c_client *client = chip->client;
71 unsigned short data;
72 int ret;
73
74 ret = ad5398_read_reg(client, &data);
75 if (ret < 0)
76 return ret;
77
78 ret = (data & chip->current_mask) >> chip->current_offset;
79
80 return ad5398_calc_current(chip, ret);
81}
82
83static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
84{
85 struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
86 struct i2c_client *client = chip->client;
87 unsigned range_uA = chip->max_uA - chip->min_uA;
88 unsigned selector;
89 unsigned short data;
90 int ret;
91
92 if (min_uA > chip->max_uA || min_uA < chip->min_uA)
93 return -EINVAL;
94 if (max_uA > chip->max_uA || max_uA < chip->min_uA)
95 return -EINVAL;
96
Axel Lin8148ed62012-03-02 16:20:54 +080097 selector = DIV_ROUND_UP((min_uA - chip->min_uA) * chip->current_level,
98 range_uA);
Sonic Zhang8b385d92010-06-04 11:46:04 +080099 if (ad5398_calc_current(chip, selector) > max_uA)
100 return -EINVAL;
101
Axel Lin935c14a2012-03-27 10:08:25 +0800102 dev_dbg(&client->dev, "changing current %duA\n",
103 ad5398_calc_current(chip, selector));
Sonic Zhang8b385d92010-06-04 11:46:04 +0800104
105 /* read chip enable bit */
106 ret = ad5398_read_reg(client, &data);
107 if (ret < 0)
108 return ret;
109
110 /* prepare register data */
111 selector = (selector << chip->current_offset) & chip->current_mask;
112 data = (unsigned short)selector | (data & AD5398_CURRENT_EN_MASK);
113
114 /* write the new current value back as well as enable bit */
115 ret = ad5398_write_reg(client, data);
116
117 return ret;
118}
119
120static int ad5398_is_enabled(struct regulator_dev *rdev)
121{
122 struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
123 struct i2c_client *client = chip->client;
124 unsigned short data;
125 int ret;
126
127 ret = ad5398_read_reg(client, &data);
128 if (ret < 0)
129 return ret;
130
131 if (data & AD5398_CURRENT_EN_MASK)
132 return 1;
133 else
134 return 0;
135}
136
137static int ad5398_enable(struct regulator_dev *rdev)
138{
139 struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
140 struct i2c_client *client = chip->client;
141 unsigned short data;
142 int ret;
143
144 ret = ad5398_read_reg(client, &data);
145 if (ret < 0)
146 return ret;
147
148 if (data & AD5398_CURRENT_EN_MASK)
149 return 0;
150
151 data |= AD5398_CURRENT_EN_MASK;
152
153 ret = ad5398_write_reg(client, data);
154
155 return ret;
156}
157
158static int ad5398_disable(struct regulator_dev *rdev)
159{
160 struct ad5398_chip_info *chip = rdev_get_drvdata(rdev);
161 struct i2c_client *client = chip->client;
162 unsigned short data;
163 int ret;
164
165 ret = ad5398_read_reg(client, &data);
166 if (ret < 0)
167 return ret;
168
169 if (!(data & AD5398_CURRENT_EN_MASK))
170 return 0;
171
172 data &= ~AD5398_CURRENT_EN_MASK;
173
174 ret = ad5398_write_reg(client, data);
175
176 return ret;
177}
178
179static struct regulator_ops ad5398_ops = {
180 .get_current_limit = ad5398_get_current_limit,
181 .set_current_limit = ad5398_set_current_limit,
182 .enable = ad5398_enable,
183 .disable = ad5398_disable,
184 .is_enabled = ad5398_is_enabled,
185};
186
Axel Lin487f71e2012-04-05 11:56:56 +0800187static const struct regulator_desc ad5398_reg = {
Sonic Zhang8b385d92010-06-04 11:46:04 +0800188 .name = "isink",
189 .id = 0,
190 .ops = &ad5398_ops,
191 .type = REGULATOR_CURRENT,
192 .owner = THIS_MODULE,
193};
194
195struct ad5398_current_data_format {
196 int current_bits;
197 int current_offset;
198 int min_uA;
199 int max_uA;
200};
201
202static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000};
203
204static const struct i2c_device_id ad5398_id[] = {
205 { "ad5398", (kernel_ulong_t)&df_10_4_120 },
206 { "ad5821", (kernel_ulong_t)&df_10_4_120 },
207 { }
208};
209MODULE_DEVICE_TABLE(i2c, ad5398_id);
210
211static int __devinit ad5398_probe(struct i2c_client *client,
212 const struct i2c_device_id *id)
213{
Sonic Zhang8b385d92010-06-04 11:46:04 +0800214 struct regulator_init_data *init_data = client->dev.platform_data;
Mark Brownc1727082012-04-04 00:50:22 +0100215 struct regulator_config config = { };
Sonic Zhang8b385d92010-06-04 11:46:04 +0800216 struct ad5398_chip_info *chip;
217 const struct ad5398_current_data_format *df =
218 (struct ad5398_current_data_format *)id->driver_data;
219 int ret;
220
221 if (!init_data)
222 return -EINVAL;
223
Axel Lin0df8c962012-03-27 10:09:42 +0800224 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
Sonic Zhang8b385d92010-06-04 11:46:04 +0800225 if (!chip)
226 return -ENOMEM;
227
Mark Brownc1727082012-04-04 00:50:22 +0100228 config.dev = &client->dev;
229 config.init_data = init_data;
230 config.driver_data = chip;
231
Sonic Zhang8b385d92010-06-04 11:46:04 +0800232 chip->client = client;
233
234 chip->min_uA = df->min_uA;
235 chip->max_uA = df->max_uA;
236 chip->current_level = 1 << df->current_bits;
237 chip->current_offset = df->current_offset;
238 chip->current_mask = (chip->current_level - 1) << chip->current_offset;
239
Mark Brownc1727082012-04-04 00:50:22 +0100240 chip->rdev = regulator_register(&ad5398_reg, &config);
Axel Lin58d463e2010-09-01 10:29:18 +0800241 if (IS_ERR(chip->rdev)) {
242 ret = PTR_ERR(chip->rdev);
Sonic Zhang8b385d92010-06-04 11:46:04 +0800243 dev_err(&client->dev, "failed to register %s %s\n",
244 id->name, ad5398_reg.name);
245 goto err;
246 }
247
248 i2c_set_clientdata(client, chip);
249 dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
250 return 0;
251
252err:
Sonic Zhang8b385d92010-06-04 11:46:04 +0800253 return ret;
254}
255
256static int __devexit ad5398_remove(struct i2c_client *client)
257{
258 struct ad5398_chip_info *chip = i2c_get_clientdata(client);
259
Axel Lin58d463e2010-09-01 10:29:18 +0800260 regulator_unregister(chip->rdev);
Sonic Zhang8b385d92010-06-04 11:46:04 +0800261 return 0;
262}
263
264static struct i2c_driver ad5398_driver = {
265 .probe = ad5398_probe,
266 .remove = __devexit_p(ad5398_remove),
267 .driver = {
268 .name = "ad5398",
269 },
270 .id_table = ad5398_id,
271};
272
273static int __init ad5398_init(void)
274{
275 return i2c_add_driver(&ad5398_driver);
276}
Sonic Zhang839b8362010-06-10 16:50:20 +0800277subsys_initcall(ad5398_init);
Sonic Zhang8b385d92010-06-04 11:46:04 +0800278
279static void __exit ad5398_exit(void)
280{
281 i2c_del_driver(&ad5398_driver);
282}
283module_exit(ad5398_exit);
284
285MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
286MODULE_AUTHOR("Sonic Zhang");
287MODULE_LICENSE("GPL");
288MODULE_ALIAS("i2c:ad5398-regulator");