tjh.dev
Linux kernel mirror (for testing)
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kernel
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linux
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#include <linux/regmap.h>
20
21#define MAX8649_DCDC_VMIN 750000 /* uV */
22#define MAX8649_DCDC_VMAX 1380000 /* uV */
23#define MAX8649_DCDC_STEP 10000 /* uV */
24#define MAX8649_VOL_MASK 0x3f
25
26/* Registers */
27#define MAX8649_MODE0 0x00
28#define MAX8649_MODE1 0x01
29#define MAX8649_MODE2 0x02
30#define MAX8649_MODE3 0x03
31#define MAX8649_CONTROL 0x04
32#define MAX8649_SYNC 0x05
33#define MAX8649_RAMP 0x06
34#define MAX8649_CHIP_ID1 0x08
35#define MAX8649_CHIP_ID2 0x09
36
37/* Bits */
38#define MAX8649_EN_PD (1 << 7)
39#define MAX8649_VID0_PD (1 << 6)
40#define MAX8649_VID1_PD (1 << 5)
41#define MAX8649_VID_MASK (3 << 5)
42
43#define MAX8649_FORCE_PWM (1 << 7)
44#define MAX8649_SYNC_EXTCLK (1 << 6)
45
46#define MAX8649_EXT_MASK (3 << 6)
47
48#define MAX8649_RAMP_MASK (7 << 5)
49#define MAX8649_RAMP_DOWN (1 << 1)
50
51struct max8649_regulator_info {
52 struct regulator_dev *regulator;
53 struct device *dev;
54 struct regmap *regmap;
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
66static inline int check_range(int min_uV, int max_uV)
67{
68 if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
69 || (min_uV > max_uV))
70 return -EINVAL;
71 return 0;
72}
73
74static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
75{
76 return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
77}
78
79static int max8649_get_voltage(struct regulator_dev *rdev)
80{
81 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
82 unsigned int val;
83 unsigned char data;
84 int ret;
85
86 ret = regmap_read(info->regmap, info->vol_reg, &val);
87 if (ret != 0)
88 return ret;
89 data = (unsigned char)val & MAX8649_VOL_MASK;
90 return max8649_list_voltage(rdev, data);
91}
92
93static int max8649_set_voltage(struct regulator_dev *rdev,
94 int min_uV, int max_uV, unsigned *selector)
95{
96 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
97 unsigned char data, mask;
98
99 if (check_range(min_uV, max_uV)) {
100 dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
101 min_uV, max_uV);
102 return -EINVAL;
103 }
104 data = DIV_ROUND_UP(min_uV - MAX8649_DCDC_VMIN, MAX8649_DCDC_STEP);
105 mask = MAX8649_VOL_MASK;
106 *selector = data & mask;
107
108 return regmap_update_bits(info->regmap, info->vol_reg, mask, data);
109}
110
111/* EN_PD means pulldown on EN input */
112static int max8649_enable(struct regulator_dev *rdev)
113{
114 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
115 return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD, 0);
116}
117
118/*
119 * Applied internal pulldown resistor on EN input pin.
120 * If pulldown EN pin outside, it would be better.
121 */
122static int max8649_disable(struct regulator_dev *rdev)
123{
124 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
125 return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD,
126 MAX8649_EN_PD);
127}
128
129static int max8649_is_enabled(struct regulator_dev *rdev)
130{
131 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
132 unsigned int val;
133 int ret;
134
135 ret = regmap_read(info->regmap, MAX8649_CONTROL, &val);
136 if (ret != 0)
137 return ret;
138 return !((unsigned char)val & MAX8649_EN_PD);
139}
140
141static int max8649_enable_time(struct regulator_dev *rdev)
142{
143 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
144 int voltage, rate, ret;
145 unsigned int val;
146
147 /* get voltage */
148 ret = regmap_read(info->regmap, info->vol_reg, &val);
149 if (ret != 0)
150 return ret;
151 val &= MAX8649_VOL_MASK;
152 voltage = max8649_list_voltage(rdev, (unsigned char)val); /* uV */
153
154 /* get rate */
155 ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
156 if (ret != 0)
157 return ret;
158 ret = (val & MAX8649_RAMP_MASK) >> 5;
159 rate = (32 * 1000) >> ret; /* uV/uS */
160
161 return DIV_ROUND_UP(voltage, rate);
162}
163
164static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
165{
166 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
167
168 switch (mode) {
169 case REGULATOR_MODE_FAST:
170 regmap_update_bits(info->regmap, info->vol_reg, MAX8649_FORCE_PWM,
171 MAX8649_FORCE_PWM);
172 break;
173 case REGULATOR_MODE_NORMAL:
174 regmap_update_bits(info->regmap, info->vol_reg,
175 MAX8649_FORCE_PWM, 0);
176 break;
177 default:
178 return -EINVAL;
179 }
180 return 0;
181}
182
183static unsigned int max8649_get_mode(struct regulator_dev *rdev)
184{
185 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
186 unsigned int val;
187 int ret;
188
189 ret = regmap_read(info->regmap, info->vol_reg, &val);
190 if (ret != 0)
191 return ret;
192 if (val & MAX8649_FORCE_PWM)
193 return REGULATOR_MODE_FAST;
194 return REGULATOR_MODE_NORMAL;
195}
196
197static struct regulator_ops max8649_dcdc_ops = {
198 .set_voltage = max8649_set_voltage,
199 .get_voltage = max8649_get_voltage,
200 .list_voltage = max8649_list_voltage,
201 .enable = max8649_enable,
202 .disable = max8649_disable,
203 .is_enabled = max8649_is_enabled,
204 .enable_time = max8649_enable_time,
205 .set_mode = max8649_set_mode,
206 .get_mode = max8649_get_mode,
207
208};
209
210static struct regulator_desc dcdc_desc = {
211 .name = "max8649",
212 .ops = &max8649_dcdc_ops,
213 .type = REGULATOR_VOLTAGE,
214 .n_voltages = 1 << 6,
215 .owner = THIS_MODULE,
216};
217
218static struct regmap_config max8649_regmap_config = {
219 .reg_bits = 8,
220 .val_bits = 8,
221};
222
223static int __devinit max8649_regulator_probe(struct i2c_client *client,
224 const struct i2c_device_id *id)
225{
226 struct max8649_platform_data *pdata = client->dev.platform_data;
227 struct max8649_regulator_info *info = NULL;
228 unsigned int val;
229 unsigned char data;
230 int ret;
231
232 info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
233 if (!info) {
234 dev_err(&client->dev, "No enough memory\n");
235 return -ENOMEM;
236 }
237
238 info->regmap = regmap_init_i2c(client, &max8649_regmap_config);
239 if (IS_ERR(info->regmap)) {
240 ret = PTR_ERR(info->regmap);
241 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
242 goto fail;
243 }
244
245 info->dev = &client->dev;
246 i2c_set_clientdata(client, info);
247
248 info->mode = pdata->mode;
249 switch (info->mode) {
250 case 0:
251 info->vol_reg = MAX8649_MODE0;
252 break;
253 case 1:
254 info->vol_reg = MAX8649_MODE1;
255 break;
256 case 2:
257 info->vol_reg = MAX8649_MODE2;
258 break;
259 case 3:
260 info->vol_reg = MAX8649_MODE3;
261 break;
262 default:
263 break;
264 }
265
266 ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
267 if (ret != 0) {
268 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
269 ret);
270 goto out;
271 }
272 dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
273
274 /* enable VID0 & VID1 */
275 regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
276
277 /* enable/disable external clock synchronization */
278 info->extclk = pdata->extclk;
279 data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
280 regmap_update_bits(info->regmap, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
281 if (info->extclk) {
282 /* set external clock frequency */
283 info->extclk_freq = pdata->extclk_freq;
284 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
285 info->extclk_freq << 6);
286 }
287
288 if (pdata->ramp_timing) {
289 info->ramp_timing = pdata->ramp_timing;
290 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
291 info->ramp_timing << 5);
292 }
293
294 info->ramp_down = pdata->ramp_down;
295 if (info->ramp_down) {
296 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
297 MAX8649_RAMP_DOWN);
298 }
299
300 info->regulator = regulator_register(&dcdc_desc, &client->dev,
301 pdata->regulator, info, NULL);
302 if (IS_ERR(info->regulator)) {
303 dev_err(info->dev, "failed to register regulator %s\n",
304 dcdc_desc.name);
305 ret = PTR_ERR(info->regulator);
306 goto out;
307 }
308
309 dev_info(info->dev, "Max8649 regulator device is detected.\n");
310 return 0;
311out:
312 regmap_exit(info->regmap);
313fail:
314 kfree(info);
315 return ret;
316}
317
318static int __devexit max8649_regulator_remove(struct i2c_client *client)
319{
320 struct max8649_regulator_info *info = i2c_get_clientdata(client);
321
322 if (info) {
323 if (info->regulator)
324 regulator_unregister(info->regulator);
325 regmap_exit(info->regmap);
326 kfree(info);
327 }
328
329 return 0;
330}
331
332static const struct i2c_device_id max8649_id[] = {
333 { "max8649", 0 },
334 { }
335};
336MODULE_DEVICE_TABLE(i2c, max8649_id);
337
338static struct i2c_driver max8649_driver = {
339 .probe = max8649_regulator_probe,
340 .remove = __devexit_p(max8649_regulator_remove),
341 .driver = {
342 .name = "max8649",
343 },
344 .id_table = max8649_id,
345};
346
347static int __init max8649_init(void)
348{
349 return i2c_add_driver(&max8649_driver);
350}
351subsys_initcall(max8649_init);
352
353static void __exit max8649_exit(void)
354{
355 i2c_del_driver(&max8649_driver);
356}
357module_exit(max8649_exit);
358
359/* Module information */
360MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
361MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
362MODULE_LICENSE("GPL");
363