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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;
28 struct regulator_dev *rdev;
29};
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
97 selector = ((min_uA - chip->min_uA) * chip->current_level +
98 range_uA - 1) / range_uA;
99 if (ad5398_calc_current(chip, selector) > max_uA)
100 return -EINVAL;
101
102 dev_dbg(&client->dev, "changing current %dmA\n",
103 ad5398_calc_current(chip, selector) / 1000);
104
105
106 ret = ad5398_read_reg(client, &data);
107 if (ret < 0)
108 return ret;
109
110
111 selector = (selector << chip->current_offset) & chip->current_mask;
112 data = (unsigned short)selector | (data & AD5398_CURRENT_EN_MASK);
113
114
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
187static struct regulator_desc ad5398_reg = {
188 .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{
214 struct regulator_init_data *init_data = client->dev.platform_data;
215 struct ad5398_chip_info *chip;
216 const struct ad5398_current_data_format *df =
217 (struct ad5398_current_data_format *)id->driver_data;
218 int ret;
219
220 if (!init_data)
221 return -EINVAL;
222
223 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
224 if (!chip)
225 return -ENOMEM;
226
227 chip->client = client;
228
229 chip->min_uA = df->min_uA;
230 chip->max_uA = df->max_uA;
231 chip->current_level = 1 << df->current_bits;
232 chip->current_offset = df->current_offset;
233 chip->current_mask = (chip->current_level - 1) << chip->current_offset;
234
235 chip->rdev = regulator_register(&ad5398_reg, &client->dev,
236 init_data, chip);
237 if (IS_ERR(chip->rdev)) {
238 ret = PTR_ERR(chip->rdev);
239 dev_err(&client->dev, "failed to register %s %s\n",
240 id->name, ad5398_reg.name);
241 goto err;
242 }
243
244 i2c_set_clientdata(client, chip);
245 dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name);
246 return 0;
247
248err:
249 kfree(chip);
250 return ret;
251}
252
253static int __devexit ad5398_remove(struct i2c_client *client)
254{
255 struct ad5398_chip_info *chip = i2c_get_clientdata(client);
256
257 regulator_unregister(chip->rdev);
258 kfree(chip);
259
260 return 0;
261}
262
263static struct i2c_driver ad5398_driver = {
264 .probe = ad5398_probe,
265 .remove = __devexit_p(ad5398_remove),
266 .driver = {
267 .name = "ad5398",
268 },
269 .id_table = ad5398_id,
270};
271
272static int __init ad5398_init(void)
273{
274 return i2c_add_driver(&ad5398_driver);
275}
276subsys_initcall(ad5398_init);
277
278static void __exit ad5398_exit(void)
279{
280 i2c_del_driver(&ad5398_driver);
281}
282module_exit(ad5398_exit);
283
284MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver");
285MODULE_AUTHOR("Sonic Zhang");
286MODULE_LICENSE("GPL");
287MODULE_ALIAS("i2c:ad5398-regulator");
288
