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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> | |
17 | #include <linux/regulator/max8649.h> | |
18 | ||
19 | #define MAX8649_DCDC_VMIN 750000 /* uV */ | |
20 | #define MAX8649_DCDC_VMAX 1380000 /* uV */ | |
21 | #define MAX8649_DCDC_STEP 10000 /* uV */ | |
22 | #define MAX8649_VOL_MASK 0x3f | |
23 | ||
24 | /* Registers */ | |
25 | #define MAX8649_MODE0 0x00 | |
26 | #define MAX8649_MODE1 0x01 | |
27 | #define MAX8649_MODE2 0x02 | |
28 | #define MAX8649_MODE3 0x03 | |
29 | #define MAX8649_CONTROL 0x04 | |
30 | #define MAX8649_SYNC 0x05 | |
31 | #define MAX8649_RAMP 0x06 | |
32 | #define MAX8649_CHIP_ID1 0x08 | |
33 | #define MAX8649_CHIP_ID2 0x09 | |
34 | ||
35 | /* Bits */ | |
36 | #define MAX8649_EN_PD (1 << 7) | |
37 | #define MAX8649_VID0_PD (1 << 6) | |
38 | #define MAX8649_VID1_PD (1 << 5) | |
39 | #define MAX8649_VID_MASK (3 << 5) | |
40 | ||
41 | #define MAX8649_FORCE_PWM (1 << 7) | |
42 | #define MAX8649_SYNC_EXTCLK (1 << 6) | |
43 | ||
44 | #define MAX8649_EXT_MASK (3 << 6) | |
45 | ||
46 | #define MAX8649_RAMP_MASK (7 << 5) | |
47 | #define MAX8649_RAMP_DOWN (1 << 1) | |
48 | ||
49 | struct max8649_regulator_info { | |
50 | struct regulator_dev *regulator; | |
51 | struct i2c_client *i2c; | |
52 | struct device *dev; | |
53 | struct mutex io_lock; | |
54 | ||
55 | int vol_reg; | |
56 | unsigned mode:2; /* bit[1:0] = VID1, VID0 */ | |
57 | unsigned extclk_freq:2; | |
58 | unsigned extclk:1; | |
59 | unsigned ramp_timing:3; | |
60 | unsigned ramp_down:1; | |
61 | }; | |
62 | ||
63 | /* I2C operations */ | |
64 | ||
65 | static inline int max8649_read_device(struct i2c_client *i2c, | |
66 | int reg, int bytes, void *dest) | |
67 | { | |
68 | unsigned char data; | |
69 | int ret; | |
70 | ||
71 | data = (unsigned char)reg; | |
72 | ret = i2c_master_send(i2c, &data, 1); | |
73 | if (ret < 0) | |
74 | return ret; | |
75 | ret = i2c_master_recv(i2c, dest, bytes); | |
76 | if (ret < 0) | |
77 | return ret; | |
78 | return 0; | |
79 | } | |
80 | ||
81 | static inline int max8649_write_device(struct i2c_client *i2c, | |
82 | int reg, int bytes, void *src) | |
83 | { | |
84 | unsigned char buf[bytes + 1]; | |
85 | int ret; | |
86 | ||
87 | buf[0] = (unsigned char)reg; | |
88 | memcpy(&buf[1], src, bytes); | |
89 | ||
90 | ret = i2c_master_send(i2c, buf, bytes + 1); | |
91 | if (ret < 0) | |
92 | return ret; | |
93 | return 0; | |
94 | } | |
95 | ||
96 | static int max8649_reg_read(struct i2c_client *i2c, int reg) | |
97 | { | |
98 | struct max8649_regulator_info *info = i2c_get_clientdata(i2c); | |
99 | unsigned char data; | |
100 | int ret; | |
101 | ||
102 | mutex_lock(&info->io_lock); | |
103 | ret = max8649_read_device(i2c, reg, 1, &data); | |
104 | mutex_unlock(&info->io_lock); | |
105 | ||
106 | if (ret < 0) | |
107 | return ret; | |
108 | return (int)data; | |
109 | } | |
110 | ||
111 | static int max8649_set_bits(struct i2c_client *i2c, int reg, | |
112 | unsigned char mask, unsigned char data) | |
113 | { | |
114 | struct max8649_regulator_info *info = i2c_get_clientdata(i2c); | |
115 | unsigned char value; | |
116 | int ret; | |
117 | ||
118 | mutex_lock(&info->io_lock); | |
119 | ret = max8649_read_device(i2c, reg, 1, &value); | |
120 | if (ret < 0) | |
121 | goto out; | |
122 | value &= ~mask; | |
123 | value |= data; | |
124 | ret = max8649_write_device(i2c, reg, 1, &value); | |
125 | out: | |
126 | mutex_unlock(&info->io_lock); | |
127 | return ret; | |
128 | } | |
129 | ||
130 | static inline int check_range(int min_uV, int max_uV) | |
131 | { | |
132 | if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX) | |
133 | || (min_uV > max_uV)) | |
134 | return -EINVAL; | |
135 | return 0; | |
136 | } | |
137 | ||
138 | static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index) | |
139 | { | |
140 | return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP); | |
141 | } | |
142 | ||
143 | static int max8649_get_voltage(struct regulator_dev *rdev) | |
144 | { | |
145 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
146 | unsigned char data; | |
147 | int ret; | |
148 | ||
149 | ret = max8649_reg_read(info->i2c, info->vol_reg); | |
150 | if (ret < 0) | |
151 | return ret; | |
152 | data = (unsigned char)ret & MAX8649_VOL_MASK; | |
153 | return max8649_list_voltage(rdev, data); | |
154 | } | |
155 | ||
156 | static int max8649_set_voltage(struct regulator_dev *rdev, | |
157 | int min_uV, int max_uV) | |
158 | { | |
159 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
160 | unsigned char data, mask; | |
161 | ||
162 | if (check_range(min_uV, max_uV)) { | |
163 | dev_err(info->dev, "invalid voltage range (%d, %d) uV\n", | |
164 | min_uV, max_uV); | |
165 | return -EINVAL; | |
166 | } | |
167 | data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1) | |
168 | / MAX8649_DCDC_STEP; | |
169 | mask = MAX8649_VOL_MASK; | |
170 | ||
171 | return max8649_set_bits(info->i2c, info->vol_reg, mask, data); | |
172 | } | |
173 | ||
174 | /* EN_PD means pulldown on EN input */ | |
175 | static int max8649_enable(struct regulator_dev *rdev) | |
176 | { | |
177 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
178 | return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0); | |
179 | } | |
180 | ||
181 | /* | |
182 | * Applied internal pulldown resistor on EN input pin. | |
183 | * If pulldown EN pin outside, it would be better. | |
184 | */ | |
185 | static int max8649_disable(struct regulator_dev *rdev) | |
186 | { | |
187 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
188 | return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, | |
189 | MAX8649_EN_PD); | |
190 | } | |
191 | ||
192 | static int max8649_is_enabled(struct regulator_dev *rdev) | |
193 | { | |
194 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
195 | int ret; | |
196 | ||
197 | ret = max8649_reg_read(info->i2c, MAX8649_CONTROL); | |
198 | if (ret < 0) | |
199 | return ret; | |
200 | return !((unsigned char)ret & MAX8649_EN_PD); | |
201 | } | |
202 | ||
203 | static int max8649_enable_time(struct regulator_dev *rdev) | |
204 | { | |
205 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
206 | int voltage, rate, ret; | |
207 | ||
208 | /* get voltage */ | |
209 | ret = max8649_reg_read(info->i2c, info->vol_reg); | |
210 | if (ret < 0) | |
211 | return ret; | |
212 | ret &= MAX8649_VOL_MASK; | |
213 | voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */ | |
214 | ||
215 | /* get rate */ | |
216 | ret = max8649_reg_read(info->i2c, MAX8649_RAMP); | |
217 | if (ret < 0) | |
218 | return ret; | |
219 | ret = (ret & MAX8649_RAMP_MASK) >> 5; | |
220 | rate = (32 * 1000) >> ret; /* uV/uS */ | |
221 | ||
222 | return (voltage / rate); | |
223 | } | |
224 | ||
225 | static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode) | |
226 | { | |
227 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
228 | ||
229 | switch (mode) { | |
230 | case REGULATOR_MODE_FAST: | |
231 | max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM, | |
232 | MAX8649_FORCE_PWM); | |
233 | break; | |
234 | case REGULATOR_MODE_NORMAL: | |
235 | max8649_set_bits(info->i2c, info->vol_reg, | |
236 | MAX8649_FORCE_PWM, 0); | |
237 | break; | |
238 | default: | |
239 | return -EINVAL; | |
240 | } | |
241 | return 0; | |
242 | } | |
243 | ||
244 | static unsigned int max8649_get_mode(struct regulator_dev *rdev) | |
245 | { | |
246 | struct max8649_regulator_info *info = rdev_get_drvdata(rdev); | |
247 | int ret; | |
248 | ||
249 | ret = max8649_reg_read(info->i2c, info->vol_reg); | |
250 | if (ret & MAX8649_FORCE_PWM) | |
251 | return REGULATOR_MODE_FAST; | |
252 | return REGULATOR_MODE_NORMAL; | |
253 | } | |
254 | ||
255 | static struct regulator_ops max8649_dcdc_ops = { | |
256 | .set_voltage = max8649_set_voltage, | |
257 | .get_voltage = max8649_get_voltage, | |
258 | .list_voltage = max8649_list_voltage, | |
259 | .enable = max8649_enable, | |
260 | .disable = max8649_disable, | |
261 | .is_enabled = max8649_is_enabled, | |
262 | .enable_time = max8649_enable_time, | |
263 | .set_mode = max8649_set_mode, | |
264 | .get_mode = max8649_get_mode, | |
265 | ||
266 | }; | |
267 | ||
268 | static struct regulator_desc dcdc_desc = { | |
269 | .name = "max8649", | |
270 | .ops = &max8649_dcdc_ops, | |
271 | .type = REGULATOR_VOLTAGE, | |
272 | .n_voltages = 1 << 6, | |
273 | .owner = THIS_MODULE, | |
274 | }; | |
275 | ||
276 | static int __devinit max8649_regulator_probe(struct i2c_client *client, | |
277 | const struct i2c_device_id *id) | |
278 | { | |
279 | struct max8649_platform_data *pdata = client->dev.platform_data; | |
280 | struct max8649_regulator_info *info = NULL; | |
281 | unsigned char data; | |
282 | int ret; | |
283 | ||
284 | info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL); | |
285 | if (!info) { | |
286 | dev_err(&client->dev, "No enough memory\n"); | |
287 | return -ENOMEM; | |
288 | } | |
289 | ||
290 | info->i2c = client; | |
291 | info->dev = &client->dev; | |
292 | mutex_init(&info->io_lock); | |
293 | i2c_set_clientdata(client, info); | |
294 | ||
295 | info->mode = pdata->mode; | |
296 | switch (info->mode) { | |
297 | case 0: | |
298 | info->vol_reg = MAX8649_MODE0; | |
299 | break; | |
300 | case 1: | |
301 | info->vol_reg = MAX8649_MODE1; | |
302 | break; | |
303 | case 2: | |
304 | info->vol_reg = MAX8649_MODE2; | |
305 | break; | |
306 | case 3: | |
307 | info->vol_reg = MAX8649_MODE3; | |
308 | break; | |
309 | default: | |
310 | break; | |
311 | } | |
312 | ||
313 | ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1); | |
314 | if (ret < 0) { | |
315 | dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n", | |
316 | ret); | |
317 | goto out; | |
318 | } | |
319 | dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret); | |
320 | ||
321 | /* enable VID0 & VID1 */ | |
322 | max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0); | |
323 | ||
324 | /* enable/disable external clock synchronization */ | |
325 | info->extclk = pdata->extclk; | |
326 | data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0; | |
327 | max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data); | |
328 | if (info->extclk) { | |
329 | /* set external clock frequency */ | |
330 | info->extclk_freq = pdata->extclk_freq; | |
331 | max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK, | |
332 | info->extclk_freq); | |
333 | } | |
334 | ||
335 | if (pdata->ramp_timing) { | |
336 | info->ramp_timing = pdata->ramp_timing; | |
337 | max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK, | |
338 | info->ramp_timing << 5); | |
339 | } | |
340 | ||
341 | info->ramp_down = pdata->ramp_down; | |
342 | if (info->ramp_down) { | |
343 | max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN, | |
344 | MAX8649_RAMP_DOWN); | |
345 | } | |
346 | ||
347 | info->regulator = regulator_register(&dcdc_desc, &client->dev, | |
348 | pdata->regulator, info); | |
349 | if (IS_ERR(info->regulator)) { | |
350 | dev_err(info->dev, "failed to register regulator %s\n", | |
351 | dcdc_desc.name); | |
352 | ret = PTR_ERR(info->regulator); | |
353 | goto out; | |
354 | } | |
355 | ||
356 | dev_info(info->dev, "Max8649 regulator device is detected.\n"); | |
357 | return 0; | |
358 | out: | |
8b4709ec | 359 | i2c_set_clientdata(client, NULL); |
a71b797f HZ |
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); | |
8b4709ec | 371 | i2c_set_clientdata(client, NULL); |
a71b797f HZ |
372 | kfree(info); |
373 | } | |
a71b797f HZ |
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 |