2 * Regulators driver for Maxim max8649
4 * Copyright (C) 2009-2010 Marvell International Ltd.
5 * Haojian Zhuang <haojian.zhuang@marvell.com>
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.
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>
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
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
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)
42 #define MAX8649_FORCE_PWM (1 << 7)
43 #define MAX8649_SYNC_EXTCLK (1 << 6)
45 #define MAX8649_EXT_MASK (3 << 6)
47 #define MAX8649_RAMP_MASK (7 << 5)
48 #define MAX8649_RAMP_DOWN (1 << 1)
50 struct max8649_regulator_info {
51 struct regulator_dev *regulator;
52 struct i2c_client *i2c;
57 unsigned mode:2; /* bit[1:0] = VID1, VID0 */
58 unsigned extclk_freq:2;
60 unsigned ramp_timing:3;
66 static inline int max8649_read_device(struct i2c_client *i2c,
67 int reg, int bytes, void *dest)
72 data = (unsigned char)reg;
73 ret = i2c_master_send(i2c, &data, 1);
76 ret = i2c_master_recv(i2c, dest, bytes);
82 static inline int max8649_write_device(struct i2c_client *i2c,
83 int reg, int bytes, void *src)
85 unsigned char buf[bytes + 1];
88 buf[0] = (unsigned char)reg;
89 memcpy(&buf[1], src, bytes);
91 ret = i2c_master_send(i2c, buf, bytes + 1);
97 static int max8649_reg_read(struct i2c_client *i2c, int reg)
99 struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
103 mutex_lock(&info->io_lock);
104 ret = max8649_read_device(i2c, reg, 1, &data);
105 mutex_unlock(&info->io_lock);
112 static int max8649_set_bits(struct i2c_client *i2c, int reg,
113 unsigned char mask, unsigned char data)
115 struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
119 mutex_lock(&info->io_lock);
120 ret = max8649_read_device(i2c, reg, 1, &value);
125 ret = max8649_write_device(i2c, reg, 1, &value);
127 mutex_unlock(&info->io_lock);
131 static inline int check_range(int min_uV, int max_uV)
133 if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
134 || (min_uV > max_uV))
139 static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
141 return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
144 static int max8649_get_voltage(struct regulator_dev *rdev)
146 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
150 ret = max8649_reg_read(info->i2c, info->vol_reg);
153 data = (unsigned char)ret & MAX8649_VOL_MASK;
154 return max8649_list_voltage(rdev, data);
157 static int max8649_set_voltage(struct regulator_dev *rdev,
158 int min_uV, int max_uV)
160 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
161 unsigned char data, mask;
163 if (check_range(min_uV, max_uV)) {
164 dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
168 data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1)
170 mask = MAX8649_VOL_MASK;
172 return max8649_set_bits(info->i2c, info->vol_reg, mask, data);
175 /* EN_PD means pulldown on EN input */
176 static int max8649_enable(struct regulator_dev *rdev)
178 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
179 return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0);
183 * Applied internal pulldown resistor on EN input pin.
184 * If pulldown EN pin outside, it would be better.
186 static int max8649_disable(struct regulator_dev *rdev)
188 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
189 return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD,
193 static int max8649_is_enabled(struct regulator_dev *rdev)
195 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
198 ret = max8649_reg_read(info->i2c, MAX8649_CONTROL);
201 return !((unsigned char)ret & MAX8649_EN_PD);
204 static int max8649_enable_time(struct regulator_dev *rdev)
206 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
207 int voltage, rate, ret;
210 ret = max8649_reg_read(info->i2c, info->vol_reg);
213 ret &= MAX8649_VOL_MASK;
214 voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */
217 ret = max8649_reg_read(info->i2c, MAX8649_RAMP);
220 ret = (ret & MAX8649_RAMP_MASK) >> 5;
221 rate = (32 * 1000) >> ret; /* uV/uS */
223 return (voltage / rate);
226 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
228 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
231 case REGULATOR_MODE_FAST:
232 max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM,
235 case REGULATOR_MODE_NORMAL:
236 max8649_set_bits(info->i2c, info->vol_reg,
237 MAX8649_FORCE_PWM, 0);
245 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
247 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
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;
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,
269 static struct regulator_desc dcdc_desc = {
271 .ops = &max8649_dcdc_ops,
272 .type = REGULATOR_VOLTAGE,
273 .n_voltages = 1 << 6,
274 .owner = THIS_MODULE,
277 static int __devinit max8649_regulator_probe(struct i2c_client *client,
278 const struct i2c_device_id *id)
280 struct max8649_platform_data *pdata = client->dev.platform_data;
281 struct max8649_regulator_info *info = NULL;
285 info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
287 dev_err(&client->dev, "No enough memory\n");
292 info->dev = &client->dev;
293 mutex_init(&info->io_lock);
294 i2c_set_clientdata(client, info);
296 info->mode = pdata->mode;
297 switch (info->mode) {
299 info->vol_reg = MAX8649_MODE0;
302 info->vol_reg = MAX8649_MODE1;
305 info->vol_reg = MAX8649_MODE2;
308 info->vol_reg = MAX8649_MODE3;
314 ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1);
316 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
320 dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret);
322 /* enable VID0 & VID1 */
323 max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
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);
330 /* set external clock frequency */
331 info->extclk_freq = pdata->extclk_freq;
332 max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK,
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);
342 info->ramp_down = pdata->ramp_down;
343 if (info->ramp_down) {
344 max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN,
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",
353 ret = PTR_ERR(info->regulator);
357 dev_info(info->dev, "Max8649 regulator device is detected.\n");
360 i2c_set_clientdata(client, NULL);
365 static int __devexit max8649_regulator_remove(struct i2c_client *client)
367 struct max8649_regulator_info *info = i2c_get_clientdata(client);
371 regulator_unregister(info->regulator);
372 i2c_set_clientdata(client, NULL);
379 static const struct i2c_device_id max8649_id[] = {
383 MODULE_DEVICE_TABLE(i2c, max8649_id);
385 static struct i2c_driver max8649_driver = {
386 .probe = max8649_regulator_probe,
387 .remove = __devexit_p(max8649_regulator_remove),
391 .id_table = max8649_id,
394 static int __init max8649_init(void)
396 return i2c_add_driver(&max8649_driver);
398 subsys_initcall(max8649_init);
400 static void __exit max8649_exit(void)
402 i2c_del_driver(&max8649_driver);
404 module_exit(max8649_exit);
406 /* Module information */
407 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
408 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
409 MODULE_LICENSE("GPL");