1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Regulators driver for Maxim max8649
4 *
5 * Copyright (C) 2009-2010 Marvell International Ltd.
6 * Haojian Zhuang <haojian.zhuang@marvell.com>
7 */
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/err.h>
11 #include <linux/i2c.h>
12 #include <linux/platform_device.h>
13 #include <linux/regulator/driver.h>
14 #include <linux/slab.h>
15 #include <linux/regulator/max8649.h>
16 #include <linux/regmap.h>
17
18 #define MAX8649_DCDC_VMIN 750000 /* uV */
19 #define MAX8649_DCDC_VMAX 1380000 /* uV */
20 #define MAX8649_DCDC_STEP 10000 /* uV */
21 #define MAX8649_VOL_MASK 0x3f
22
23 /* Registers */
24 #define MAX8649_MODE0 0x00
25 #define MAX8649_MODE1 0x01
26 #define MAX8649_MODE2 0x02
27 #define MAX8649_MODE3 0x03
28 #define MAX8649_CONTROL 0x04
29 #define MAX8649_SYNC 0x05
30 #define MAX8649_RAMP 0x06
31 #define MAX8649_CHIP_ID1 0x08
32 #define MAX8649_CHIP_ID2 0x09
33
34 /* Bits */
35 #define MAX8649_EN_PD (1 << 7)
36 #define MAX8649_VID0_PD (1 << 6)
37 #define MAX8649_VID1_PD (1 << 5)
38 #define MAX8649_VID_MASK (3 << 5)
39
40 #define MAX8649_FORCE_PWM (1 << 7)
41 #define MAX8649_SYNC_EXTCLK (1 << 6)
42
43 #define MAX8649_EXT_MASK (3 << 6)
44
45 #define MAX8649_RAMP_MASK (7 << 5)
46 #define MAX8649_RAMP_DOWN (1 << 1)
47
48 struct max8649_regulator_info {
49 struct device *dev;
50 struct regmap *regmap;
51
52 unsigned mode:2; /* bit[1:0] = VID1, VID0 */
53 unsigned extclk_freq:2;
54 unsigned extclk:1;
55 unsigned ramp_timing:3;
56 unsigned ramp_down:1;
57 };
58
max8649_enable_time(struct regulator_dev * rdev)59 static int max8649_enable_time(struct regulator_dev *rdev)
60 {
61 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
62 int voltage, rate, ret;
63 unsigned int val;
64
65 /* get voltage */
66 ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
67 if (ret != 0)
68 return ret;
69 val &= MAX8649_VOL_MASK;
70 voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
71
72 /* get rate */
73 ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
74 if (ret != 0)
75 return ret;
76 ret = (val & MAX8649_RAMP_MASK) >> 5;
77 rate = (32 * 1000) >> ret; /* uV/uS */
78
79 return DIV_ROUND_UP(voltage, rate);
80 }
81
max8649_set_mode(struct regulator_dev * rdev,unsigned int mode)82 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
83 {
84 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
85
86 switch (mode) {
87 case REGULATOR_MODE_FAST:
88 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
89 MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
90 break;
91 case REGULATOR_MODE_NORMAL:
92 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
93 MAX8649_FORCE_PWM, 0);
94 break;
95 default:
96 return -EINVAL;
97 }
98 return 0;
99 }
100
max8649_get_mode(struct regulator_dev * rdev)101 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
102 {
103 struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
104 unsigned int val;
105 int ret;
106
107 ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
108 if (ret != 0)
109 return ret;
110 if (val & MAX8649_FORCE_PWM)
111 return REGULATOR_MODE_FAST;
112 return REGULATOR_MODE_NORMAL;
113 }
114
115 static const struct regulator_ops max8649_dcdc_ops = {
116 .set_voltage_sel = regulator_set_voltage_sel_regmap,
117 .get_voltage_sel = regulator_get_voltage_sel_regmap,
118 .list_voltage = regulator_list_voltage_linear,
119 .map_voltage = regulator_map_voltage_linear,
120 .enable = regulator_enable_regmap,
121 .disable = regulator_disable_regmap,
122 .is_enabled = regulator_is_enabled_regmap,
123 .enable_time = max8649_enable_time,
124 .set_mode = max8649_set_mode,
125 .get_mode = max8649_get_mode,
126
127 };
128
129 static struct regulator_desc dcdc_desc = {
130 .name = "max8649",
131 .ops = &max8649_dcdc_ops,
132 .type = REGULATOR_VOLTAGE,
133 .n_voltages = 1 << 6,
134 .owner = THIS_MODULE,
135 .vsel_mask = MAX8649_VOL_MASK,
136 .min_uV = MAX8649_DCDC_VMIN,
137 .uV_step = MAX8649_DCDC_STEP,
138 .enable_reg = MAX8649_CONTROL,
139 .enable_mask = MAX8649_EN_PD,
140 .enable_is_inverted = true,
141 };
142
143 static const struct regmap_config max8649_regmap_config = {
144 .reg_bits = 8,
145 .val_bits = 8,
146 };
147
max8649_regulator_probe(struct i2c_client * client)148 static int max8649_regulator_probe(struct i2c_client *client)
149 {
150 struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
151 struct max8649_regulator_info *info = NULL;
152 struct regulator_dev *regulator;
153 struct regulator_config config = { };
154 unsigned int val;
155 unsigned char data;
156 int ret;
157
158 info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
159 GFP_KERNEL);
160 if (!info)
161 return -ENOMEM;
162
163 info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
164 if (IS_ERR(info->regmap)) {
165 ret = PTR_ERR(info->regmap);
166 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
167 return ret;
168 }
169
170 info->dev = &client->dev;
171 i2c_set_clientdata(client, info);
172
173 info->mode = pdata->mode;
174 switch (info->mode) {
175 case 0:
176 dcdc_desc.vsel_reg = MAX8649_MODE0;
177 break;
178 case 1:
179 dcdc_desc.vsel_reg = MAX8649_MODE1;
180 break;
181 case 2:
182 dcdc_desc.vsel_reg = MAX8649_MODE2;
183 break;
184 case 3:
185 dcdc_desc.vsel_reg = MAX8649_MODE3;
186 break;
187 default:
188 break;
189 }
190
191 ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
192 if (ret != 0) {
193 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
194 ret);
195 return ret;
196 }
197 dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
198
199 /* enable VID0 & VID1 */
200 regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
201
202 /* enable/disable external clock synchronization */
203 info->extclk = pdata->extclk;
204 data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
205 regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
206 MAX8649_SYNC_EXTCLK, data);
207 if (info->extclk) {
208 /* set external clock frequency */
209 info->extclk_freq = pdata->extclk_freq;
210 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
211 info->extclk_freq << 6);
212 }
213
214 if (pdata->ramp_timing) {
215 info->ramp_timing = pdata->ramp_timing;
216 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
217 info->ramp_timing << 5);
218 }
219
220 info->ramp_down = pdata->ramp_down;
221 if (info->ramp_down) {
222 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
223 MAX8649_RAMP_DOWN);
224 }
225
226 config.dev = &client->dev;
227 config.init_data = pdata->regulator;
228 config.driver_data = info;
229 config.regmap = info->regmap;
230
231 regulator = devm_regulator_register(&client->dev, &dcdc_desc,
232 &config);
233 if (IS_ERR(regulator)) {
234 dev_err(info->dev, "failed to register regulator %s\n",
235 dcdc_desc.name);
236 return PTR_ERR(regulator);
237 }
238
239 return 0;
240 }
241
242 static const struct i2c_device_id max8649_id[] = {
243 { "max8649" },
244 { }
245 };
246 MODULE_DEVICE_TABLE(i2c, max8649_id);
247
248 static struct i2c_driver max8649_driver = {
249 .probe = max8649_regulator_probe,
250 .driver = {
251 .name = "max8649",
252 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
253 },
254 .id_table = max8649_id,
255 };
256
max8649_init(void)257 static int __init max8649_init(void)
258 {
259 return i2c_add_driver(&max8649_driver);
260 }
261 subsys_initcall(max8649_init);
262
max8649_exit(void)263 static void __exit max8649_exit(void)
264 {
265 i2c_del_driver(&max8649_driver);
266 }
267 module_exit(max8649_exit);
268
269 /* Module information */
270 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
271 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
272 MODULE_LICENSE("GPL");
273