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a71b797f HZ |
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> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
a71b797f HZ |
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) | |
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 | ||
172 | return max8649_set_bits(info->i2c, info->vol_reg, mask, data); | |
173 | } | |
174 | ||
175 | /* EN_PD means pulldown on EN input */ | |
176 | static int max8649_enable(struct regulator_dev *rdev) | |
177 | { | |
178 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
179 | return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0); | |
180 | } | |
181 | ||
182 | /* | |
183 | * Applied internal pulldown resistor on EN input pin. | |
184 | * If pulldown EN pin outside, it would be better. | |
185 | */ | |
186 | static int max8649_disable(struct regulator_dev *rdev) | |
187 | { | |
188 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
189 | return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, | |
190 | MAX8649_EN_PD); | |
191 | } | |
192 | ||
193 | static int max8649_is_enabled(struct regulator_dev *rdev) | |
194 | { | |
195 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
196 | int ret; | |
197 | ||
198 | ret = max8649_reg_read(info->i2c, MAX8649_CONTROL); | |
199 | if (ret < 0) | |
200 | return ret; | |
201 | return !((unsigned char)ret & MAX8649_EN_PD); | |
202 | } | |
203 | ||
204 | static int max8649_enable_time(struct regulator_dev *rdev) | |
205 | { | |
206 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
207 | int voltage, rate, ret; | |
208 | ||
209 | /* get voltage */ | |
210 | ret = max8649_reg_read(info->i2c, info->vol_reg); | |
211 | if (ret < 0) | |
212 | return ret; | |
213 | ret &= MAX8649_VOL_MASK; | |
214 | voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */ | |
215 | ||
216 | /* get rate */ | |
217 | ret = max8649_reg_read(info->i2c, MAX8649_RAMP); | |
218 | if (ret < 0) | |
219 | return ret; | |
220 | ret = (ret & MAX8649_RAMP_MASK) >> 5; | |
221 | rate = (32 * 1000) >> ret; /* uV/uS */ | |
222 | ||
223 | return (voltage / rate); | |
224 | } | |
225 | ||
226 | static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode) | |
227 | { | |
228 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
229 | ||
230 | switch (mode) { | |
231 | case REGULATOR_MODE_FAST: | |
232 | max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM, | |
233 | MAX8649_FORCE_PWM); | |
234 | break; | |
235 | case REGULATOR_MODE_NORMAL: | |
236 | max8649_set_bits(info->i2c, info->vol_reg, | |
237 | MAX8649_FORCE_PWM, 0); | |
238 | break; | |
239 | default: | |
240 | return -EINVAL; | |
241 | } | |
242 | return 0; | |
243 | } | |
244 | ||
245 | static unsigned int max8649_get_mode(struct regulator_dev *rdev) | |
246 | { | |
247 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
248 | int ret; | |
249 | ||
250 | ret = max8649_reg_read(info->i2c, info->vol_reg); | |
251 | if (ret & MAX8649_FORCE_PWM) | |
252 | return REGULATOR_MODE_FAST; | |
253 | return REGULATOR_MODE_NORMAL; | |
254 | } | |
255 | ||
256 | static struct regulator_ops max8649_dcdc_ops = { | |
257 | .set_voltage = max8649_set_voltage, | |
258 | .get_voltage = max8649_get_voltage, | |
259 | .list_voltage = max8649_list_voltage, | |
260 | .enable = max8649_enable, | |
261 | .disable = max8649_disable, | |
262 | .is_enabled = max8649_is_enabled, | |
263 | .enable_time = max8649_enable_time, | |
264 | .set_mode = max8649_set_mode, | |
265 | .get_mode = max8649_get_mode, | |
266 | ||
267 | }; | |
268 | ||
269 | static struct regulator_desc dcdc_desc = { | |
270 | .name = "max8649", | |
271 | .ops = &max8649_dcdc_ops, | |
272 | .type = REGULATOR_VOLTAGE, | |
273 | .n_voltages = 1 << 6, | |
274 | .owner = THIS_MODULE, | |
275 | }; | |
276 | ||
277 | static int __devinit max8649_regulator_probe(struct i2c_client *client, | |
278 | const struct i2c_device_id *id) | |
279 | { | |
280 | struct max8649_platform_data *pdata = client->dev.platform_data; | |
281 | struct max8649_regulator_info *info = NULL; | |
282 | unsigned char data; | |
283 | int ret; | |
284 | ||
285 | info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL); | |
286 | if (!info) { | |
287 | dev_err(&client->dev, "No enough memory\n"); | |
288 | return -ENOMEM; | |
289 | } | |
290 | ||
291 | info->i2c = client; | |
292 | info->dev = &client->dev; | |
293 | mutex_init(&info->io_lock); | |
294 | i2c_set_clientdata(client, info); | |
295 | ||
296 | info->mode = pdata->mode; | |
297 | switch (info->mode) { | |
298 | case 0: | |
299 | info->vol_reg = MAX8649_MODE0; | |
300 | break; | |
301 | case 1: | |
302 | info->vol_reg = MAX8649_MODE1; | |
303 | break; | |
304 | case 2: | |
305 | info->vol_reg = MAX8649_MODE2; | |
306 | break; | |
307 | case 3: | |
308 | info->vol_reg = MAX8649_MODE3; | |
309 | break; | |
310 | default: | |
311 | break; | |
312 | } | |
313 | ||
314 | ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1); | |
315 | if (ret < 0) { | |
316 | dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n", | |
317 | ret); | |
318 | goto out; | |
319 | } | |
320 | dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret); | |
321 | ||
322 | /* enable VID0 & VID1 */ | |
323 | max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0); | |
324 | ||
325 | /* enable/disable external clock synchronization */ | |
326 | info->extclk = pdata->extclk; | |
327 | data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0; | |
328 | max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data); | |
329 | if (info->extclk) { | |
330 | /* set external clock frequency */ | |
331 | info->extclk_freq = pdata->extclk_freq; | |
332 | max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK, | |
333 | info->extclk_freq); | |
334 | } | |
335 | ||
336 | if (pdata->ramp_timing) { | |
337 | info->ramp_timing = pdata->ramp_timing; | |
338 | max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK, | |
339 | info->ramp_timing << 5); | |
340 | } | |
341 | ||
342 | info->ramp_down = pdata->ramp_down; | |
343 | if (info->ramp_down) { | |
344 | max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN, | |
345 | MAX8649_RAMP_DOWN); | |
346 | } | |
347 | ||
348 | info->regulator = regulator_register(&dcdc_desc, &client->dev, | |
349 | pdata->regulator, info); | |
350 | if (IS_ERR(info->regulator)) { | |
351 | dev_err(info->dev, "failed to register regulator %s\n", | |
352 | dcdc_desc.name); | |
353 | ret = PTR_ERR(info->regulator); | |
354 | goto out; | |
355 | } | |
356 | ||
357 | dev_info(info->dev, "Max8649 regulator device is detected.\n"); | |
358 | return 0; | |
359 | out: | |
360 | kfree(info); | |
361 | return ret; | |
362 | } | |
363 | ||
364 | static int __devexit max8649_regulator_remove(struct i2c_client *client) | |
365 | { | |
366 | struct max8649_regulator_info *info = i2c_get_clientdata(client); | |
367 | ||
368 | if (info) { | |
369 | if (info->regulator) | |
370 | regulator_unregister(info->regulator); | |
371 | kfree(info); | |
372 | } | |
a71b797f HZ |
373 | |
374 | return 0; | |
375 | } | |
376 | ||
377 | static const struct i2c_device_id max8649_id[] = { | |
378 | { "max8649", 0 }, | |
379 | { } | |
380 | }; | |
381 | MODULE_DEVICE_TABLE(i2c, max8649_id); | |
382 | ||
383 | static struct i2c_driver max8649_driver = { | |
384 | .probe = max8649_regulator_probe, | |
385 | .remove = __devexit_p(max8649_regulator_remove), | |
386 | .driver = { | |
387 | .name = "max8649", | |
388 | }, | |
389 | .id_table = max8649_id, | |
390 | }; | |
391 | ||
392 | static int __init max8649_init(void) | |
393 | { | |
394 | return i2c_add_driver(&max8649_driver); | |
395 | } | |
396 | subsys_initcall(max8649_init); | |
397 | ||
398 | static void __exit max8649_exit(void) | |
399 | { | |
400 | i2c_del_driver(&max8649_driver); | |
401 | } | |
402 | module_exit(max8649_exit); | |
403 | ||
404 | /* Module information */ | |
405 | MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver"); | |
406 | MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); | |
407 | MODULE_LICENSE("GPL"); | |
408 |