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The discovered bit in PGCCSR register indicates if the device has been
[linux-2.6/next.git] / drivers / regulator / max8649.c
blob1062cf9f02dc3303a7fae53a23203dd21a7707a8
1 /*
2 * Regulators driver for Maxim max8649
3 *
4 * Copyright (C) 2009-2010 Marvell International Ltd.
5 * Haojian Zhuang <haojian.zhuang@marvell.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/platform_device.h>
16 #include <linux/regulator/driver.h>
17 #include <linux/slab.h>
18 #include <linux/regulator/max8649.h>
19
20 #define MAX8649_DCDC_VMIN 750000 /* uV */
21 #define MAX8649_DCDC_VMAX 1380000 /* uV */
22 #define MAX8649_DCDC_STEP 10000 /* uV */
23 #define MAX8649_VOL_MASK 0x3f
24
25 /* Registers */
26 #define MAX8649_MODE0 0x00
27 #define MAX8649_MODE1 0x01
28 #define MAX8649_MODE2 0x02
29 #define MAX8649_MODE3 0x03
30 #define MAX8649_CONTROL 0x04
31 #define MAX8649_SYNC 0x05
32 #define MAX8649_RAMP 0x06
33 #define MAX8649_CHIP_ID1 0x08
34 #define MAX8649_CHIP_ID2 0x09
35
36 /* Bits */
37 #define MAX8649_EN_PD (1 << 7)
38 #define MAX8649_VID0_PD (1 << 6)
39 #define MAX8649_VID1_PD (1 << 5)
40 #define MAX8649_VID_MASK (3 << 5)
41
42 #define MAX8649_FORCE_PWM (1 << 7)
43 #define MAX8649_SYNC_EXTCLK (1 << 6)
44
45 #define MAX8649_EXT_MASK (3 << 6)
46
47 #define MAX8649_RAMP_MASK (7 << 5)
48 #define MAX8649_RAMP_DOWN (1 << 1)
49
50 struct max8649_regulator_info {
51 struct regulator_dev *regulator;
52 struct i2c_client *i2c;
53 struct device *dev;
54 struct mutex io_lock;
55
56 int vol_reg;
57 unsigned mode:2; /* bit[1:0] = VID1, VID0 */
58 unsigned extclk_freq:2;
59 unsigned extclk:1;
60 unsigned ramp_timing:3;
61 unsigned ramp_down:1;
62 };
63
64 /* I2C operations */
65
66 static inline int max8649_read_device(struct i2c_client *i2c,
67 int reg, int bytes, void *dest)
68 {
69 unsigned char data;
70 int ret;
71
72 data = (unsigned char)reg;
73 ret = i2c_master_send(i2c, &data, 1);
74 if (ret < 0)
75 return ret;
76 ret = i2c_master_recv(i2c, dest, bytes);
77 if (ret < 0)
78 return ret;
79 return 0;
80 }
81
82 static inline int max8649_write_device(struct i2c_client *i2c,
83 int reg, int bytes, void *src)
84 {
85 unsigned char buf[bytes + 1];
86 int ret;
87
88 buf[0] = (unsigned char)reg;
89 memcpy(&buf[1], src, bytes);
90
91 ret = i2c_master_send(i2c, buf, bytes + 1);
92 if (ret < 0)
93 return ret;
94 return 0;
95 }
96
97 static int max8649_reg_read(struct i2c_client *i2c, int reg)
98 {
99 struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
100 unsigned char data;
101 int ret;
102
103 mutex_lock(&info->io_lock);
104 ret = max8649_read_device(i2c, reg, 1, &data);
105 mutex_unlock(&info->io_lock);
106
107 if (ret < 0)
108 return ret;
109 return (int)data;
110 }
111
112 static int max8649_set_bits(struct i2c_client *i2c, int reg,
113 unsigned char mask, unsigned char data)
114 {
115 struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
116 unsigned char value;
117 int ret;
118
119 mutex_lock(&info->io_lock);
120 ret = max8649_read_device(i2c, reg, 1, &value);
121 if (ret < 0)
122 goto out;
123 value &= ~mask;
124 value |= data;
125 ret = max8649_write_device(i2c, reg, 1, &value);
126 out:
127 mutex_unlock(&info->io_lock);
128 return ret;
129 }
130
131 static inline int check_range(int min_uV, int max_uV)
132 {
133 if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
134 || (min_uV > max_uV))
135 return -EINVAL;
136 return 0;
137 }
138
139 static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
140 {
141 return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
142 }
143
144 static int max8649_get_voltage(struct regulator_dev *rdev)
145 {
146 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
147 unsigned char data;
148 int ret;
149
150 ret = max8649_reg_read(info->i2c, info->vol_reg);
151 if (ret < 0)
152 return ret;
153 data = (unsigned char)ret & MAX8649_VOL_MASK;
154 return max8649_list_voltage(rdev, data);
155 }
156
157 static int max8649_set_voltage(struct regulator_dev *rdev,
158 int min_uV, int max_uV, unsigned *selector)
159 {
160 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
161 unsigned char data, mask;
162
163 if (check_range(min_uV, max_uV)) {
164 dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
165 min_uV, max_uV);
166 return -EINVAL;
167 }
168 data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1)
169 / MAX8649_DCDC_STEP;
170 mask = MAX8649_VOL_MASK;
171 *selector = data & mask;
172
173 return max8649_set_bits(info->i2c, info->vol_reg, mask, data);
174 }
175
176 /* EN_PD means pulldown on EN input */
177 static int max8649_enable(struct regulator_dev *rdev)
178 {
179 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
180 return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0);
181 }
182
183 /*
184 * Applied internal pulldown resistor on EN input pin.
185 * If pulldown EN pin outside, it would be better.
186 */
187 static int max8649_disable(struct regulator_dev *rdev)
188 {
189 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
190 return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD,
191 MAX8649_EN_PD);
192 }
193
194 static int max8649_is_enabled(struct regulator_dev *rdev)
195 {
196 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
197 int ret;
198
199 ret = max8649_reg_read(info->i2c, MAX8649_CONTROL);
200 if (ret < 0)
201 return ret;
202 return !((unsigned char)ret & MAX8649_EN_PD);
203 }
204
205 static int max8649_enable_time(struct regulator_dev *rdev)
206 {
207 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
208 int voltage, rate, ret;
209
210 /* get voltage */
211 ret = max8649_reg_read(info->i2c, info->vol_reg);
212 if (ret < 0)
213 return ret;
214 ret &= MAX8649_VOL_MASK;
215 voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */
216
217 /* get rate */
218 ret = max8649_reg_read(info->i2c, MAX8649_RAMP);
219 if (ret < 0)
220 return ret;
221 ret = (ret & MAX8649_RAMP_MASK) >> 5;
222 rate = (32 * 1000) >> ret; /* uV/uS */
223
224 return DIV_ROUND_UP(voltage, rate);
225 }
226
227 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
228 {
229 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
230
231 switch (mode) {
232 case REGULATOR_MODE_FAST:
233 max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM,
234 MAX8649_FORCE_PWM);
235 break;
236 case REGULATOR_MODE_NORMAL:
237 max8649_set_bits(info->i2c, info->vol_reg,
238 MAX8649_FORCE_PWM, 0);
239 break;
240 default:
241 return -EINVAL;
242 }
243 return 0;
244 }
245
246 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
247 {
248 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
249 int ret;
250
251 ret = max8649_reg_read(info->i2c, info->vol_reg);
252 if (ret & MAX8649_FORCE_PWM)
253 return REGULATOR_MODE_FAST;
254 return REGULATOR_MODE_NORMAL;
255 }
256
257 static struct regulator_ops max8649_dcdc_ops = {
258 .set_voltage = max8649_set_voltage,
259 .get_voltage = max8649_get_voltage,
260 .list_voltage = max8649_list_voltage,
261 .enable = max8649_enable,
262 .disable = max8649_disable,
263 .is_enabled = max8649_is_enabled,
264 .enable_time = max8649_enable_time,
265 .set_mode = max8649_set_mode,
266 .get_mode = max8649_get_mode,
267
268 };
269
270 static struct regulator_desc dcdc_desc = {
271 .name = "max8649",
272 .ops = &max8649_dcdc_ops,
273 .type = REGULATOR_VOLTAGE,
274 .n_voltages = 1 << 6,
275 .owner = THIS_MODULE,
276 };
277
278 static int __devinit max8649_regulator_probe(struct i2c_client *client,
279 const struct i2c_device_id *id)
280 {
281 struct max8649_platform_data *pdata = client->dev.platform_data;
282 struct max8649_regulator_info *info = NULL;
283 unsigned char data;
284 int ret;
285
286 info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
287 if (!info) {
288 dev_err(&client->dev, "No enough memory\n");
289 return -ENOMEM;
290 }
291
292 info->i2c = client;
293 info->dev = &client->dev;
294 mutex_init(&info->io_lock);
295 i2c_set_clientdata(client, info);
296
297 info->mode = pdata->mode;
298 switch (info->mode) {
299 case 0:
300 info->vol_reg = MAX8649_MODE0;
301 break;
302 case 1:
303 info->vol_reg = MAX8649_MODE1;
304 break;
305 case 2:
306 info->vol_reg = MAX8649_MODE2;
307 break;
308 case 3:
309 info->vol_reg = MAX8649_MODE3;
310 break;
311 default:
312 break;
313 }
314
315 ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1);
316 if (ret < 0) {
317 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
318 ret);
319 goto out;
320 }
321 dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret);
322
323 /* enable VID0 & VID1 */
324 max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
325
326 /* enable/disable external clock synchronization */
327 info->extclk = pdata->extclk;
328 data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
329 max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
330 if (info->extclk) {
331 /* set external clock frequency */
332 info->extclk_freq = pdata->extclk_freq;
333 max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK,
334 info->extclk_freq << 6);
335 }
336
337 if (pdata->ramp_timing) {
338 info->ramp_timing = pdata->ramp_timing;
339 max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK,
340 info->ramp_timing << 5);
341 }
342
343 info->ramp_down = pdata->ramp_down;
344 if (info->ramp_down) {
345 max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN,
346 MAX8649_RAMP_DOWN);
347 }
348
349 info->regulator = regulator_register(&dcdc_desc, &client->dev,
350 pdata->regulator, info);
351 if (IS_ERR(info->regulator)) {
352 dev_err(info->dev, "failed to register regulator %s\n",
353 dcdc_desc.name);
354 ret = PTR_ERR(info->regulator);
355 goto out;
356 }
357
358 dev_info(info->dev, "Max8649 regulator device is detected.\n");
359 return 0;
360 out:
361 kfree(info);
362 return ret;
363 }
364
365 static int __devexit max8649_regulator_remove(struct i2c_client *client)
366 {
367 struct max8649_regulator_info *info = i2c_get_clientdata(client);
368
369 if (info) {
370 if (info->regulator)
371 regulator_unregister(info->regulator);
372 kfree(info);
373 }
374
375 return 0;
376 }
377
378 static const struct i2c_device_id max8649_id[] = {
379 { "max8649", 0 },
380 { }
381 };
382 MODULE_DEVICE_TABLE(i2c, max8649_id);
383
384 static struct i2c_driver max8649_driver = {
385 .probe = max8649_regulator_probe,
386 .remove = __devexit_p(max8649_regulator_remove),
387 .driver = {
388 .name = "max8649",
389 },
390 .id_table = max8649_id,
391 };
392
393 static int __init max8649_init(void)
394 {
395 return i2c_add_driver(&max8649_driver);
396 }
397 subsys_initcall(max8649_init);
398
399 static void __exit max8649_exit(void)
400 {
401 i2c_del_driver(&max8649_driver);
402 }
403 module_exit(max8649_exit);
404
405 /* Module information */
406 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
407 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
408 MODULE_LICENSE("GPL");
409
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