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 device *dev;
53 struct regmap *regmap;
54
55 unsigned mode:2; /* bit[1:0] = VID1, VID0 */
56 unsigned extclk_freq:2;
57 unsigned extclk:1;
58 unsigned ramp_timing:3;
59 unsigned ramp_down:1;
60};
61
62static int max8649_enable_time(struct regulator_dev *rdev)
63{
64 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
65 int voltage, rate, ret;
66 unsigned int val;
67
68 /* get voltage */
69 ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
70 if (ret != 0)
71 return ret;
72 val &= MAX8649_VOL_MASK;
73 voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
74
75 /* get rate */
76 ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
77 if (ret != 0)
78 return ret;
79 ret = (val & MAX8649_RAMP_MASK) >> 5;
80 rate = (32 * 1000) >> ret; /* uV/uS */
81
82 return DIV_ROUND_UP(voltage, rate);
83}
84
85static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
86{
87 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
88
89 switch (mode) {
90 case REGULATOR_MODE_FAST:
91 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
92 MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
93 break;
94 case REGULATOR_MODE_NORMAL:
95 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
96 MAX8649_FORCE_PWM, 0);
97 break;
98 default:
99 return -EINVAL;
100 }
101 return 0;
102}
103
104static unsigned int max8649_get_mode(struct regulator_dev *rdev)
105{
106 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
107 unsigned int val;
108 int ret;
109
110 ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
111 if (ret != 0)
112 return ret;
113 if (val & MAX8649_FORCE_PWM)
114 return REGULATOR_MODE_FAST;
115 return REGULATOR_MODE_NORMAL;
116}
117
118static const struct regulator_ops max8649_dcdc_ops = {
119 .set_voltage_sel = regulator_set_voltage_sel_regmap,
120 .get_voltage_sel = regulator_get_voltage_sel_regmap,
121 .list_voltage = regulator_list_voltage_linear,
122 .map_voltage = regulator_map_voltage_linear,
123 .enable = regulator_enable_regmap,
124 .disable = regulator_disable_regmap,
125 .is_enabled = regulator_is_enabled_regmap,
126 .enable_time = max8649_enable_time,
127 .set_mode = max8649_set_mode,
128 .get_mode = max8649_get_mode,
129
130};
131
132static struct regulator_desc dcdc_desc = {
133 .name = "max8649",
134 .ops = &max8649_dcdc_ops,
135 .type = REGULATOR_VOLTAGE,
136 .n_voltages = 1 << 6,
137 .owner = THIS_MODULE,
138 .vsel_mask = MAX8649_VOL_MASK,
139 .min_uV = MAX8649_DCDC_VMIN,
140 .uV_step = MAX8649_DCDC_STEP,
141 .enable_reg = MAX8649_CONTROL,
142 .enable_mask = MAX8649_EN_PD,
143 .enable_is_inverted = true,
144};
145
146static const struct regmap_config max8649_regmap_config = {
147 .reg_bits = 8,
148 .val_bits = 8,
149};
150
151static int max8649_regulator_probe(struct i2c_client *client,
152 const struct i2c_device_id *id)
153{
154 struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
155 struct max8649_regulator_info *info = NULL;
156 struct regulator_dev *regulator;
157 struct regulator_config config = { };
158 unsigned int val;
159 unsigned char data;
160 int ret;
161
162 info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
163 GFP_KERNEL);
164 if (!info)
165 return -ENOMEM;
166
167 info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
168 if (IS_ERR(info->regmap)) {
169 ret = PTR_ERR(info->regmap);
170 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
171 return ret;
172 }
173
174 info->dev = &client->dev;
175 i2c_set_clientdata(client, info);
176
177 info->mode = pdata->mode;
178 switch (info->mode) {
179 case 0:
180 dcdc_desc.vsel_reg = MAX8649_MODE0;
181 break;
182 case 1:
183 dcdc_desc.vsel_reg = MAX8649_MODE1;
184 break;
185 case 2:
186 dcdc_desc.vsel_reg = MAX8649_MODE2;
187 break;
188 case 3:
189 dcdc_desc.vsel_reg = MAX8649_MODE3;
190 break;
191 default:
192 break;
193 }
194
195 ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
196 if (ret != 0) {
197 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
198 ret);
199 return ret;
200 }
201 dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
202
203 /* enable VID0 & VID1 */
204 regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
205
206 /* enable/disable external clock synchronization */
207 info->extclk = pdata->extclk;
208 data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
209 regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
210 MAX8649_SYNC_EXTCLK, data);
211 if (info->extclk) {
212 /* set external clock frequency */
213 info->extclk_freq = pdata->extclk_freq;
214 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
215 info->extclk_freq << 6);
216 }
217
218 if (pdata->ramp_timing) {
219 info->ramp_timing = pdata->ramp_timing;
220 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
221 info->ramp_timing << 5);
222 }
223
224 info->ramp_down = pdata->ramp_down;
225 if (info->ramp_down) {
226 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
227 MAX8649_RAMP_DOWN);
228 }
229
230 config.dev = &client->dev;
231 config.init_data = pdata->regulator;
232 config.driver_data = info;
233 config.regmap = info->regmap;
234
235 regulator = devm_regulator_register(&client->dev, &dcdc_desc,
236 &config);
237 if (IS_ERR(regulator)) {
238 dev_err(info->dev, "failed to register regulator %s\n",
239 dcdc_desc.name);
240 return PTR_ERR(regulator);
241 }
242
243 return 0;
244}
245
246static const struct i2c_device_id max8649_id[] = {
247 { "max8649", 0 },
248 { }
249};
250MODULE_DEVICE_TABLE(i2c, max8649_id);
251
252static struct i2c_driver max8649_driver = {
253 .probe = max8649_regulator_probe,
254 .driver = {
255 .name = "max8649",
256 },
257 .id_table = max8649_id,
258};
259
260static int __init max8649_init(void)
261{
262 return i2c_add_driver(&max8649_driver);
263}
264subsys_initcall(max8649_init);
265
266static void __exit max8649_exit(void)
267{
268 i2c_del_driver(&max8649_driver);
269}
270module_exit(max8649_exit);
271
272/* Module information */
273MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
274MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
275MODULE_LICENSE("GPL");
276