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,const struct i2c_device_id * id)148 static int max8649_regulator_probe(struct i2c_client *client,
149 					     const struct i2c_device_id *id)
150 {
151 	struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
152 	struct max8649_regulator_info *info = NULL;
153 	struct regulator_dev *regulator;
154 	struct regulator_config config = { };
155 	unsigned int val;
156 	unsigned char data;
157 	int ret;
158 
159 	info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
160 			    GFP_KERNEL);
161 	if (!info)
162 		return -ENOMEM;
163 
164 	info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
165 	if (IS_ERR(info->regmap)) {
166 		ret = PTR_ERR(info->regmap);
167 		dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
168 		return ret;
169 	}
170 
171 	info->dev = &client->dev;
172 	i2c_set_clientdata(client, info);
173 
174 	info->mode = pdata->mode;
175 	switch (info->mode) {
176 	case 0:
177 		dcdc_desc.vsel_reg = MAX8649_MODE0;
178 		break;
179 	case 1:
180 		dcdc_desc.vsel_reg = MAX8649_MODE1;
181 		break;
182 	case 2:
183 		dcdc_desc.vsel_reg = MAX8649_MODE2;
184 		break;
185 	case 3:
186 		dcdc_desc.vsel_reg = MAX8649_MODE3;
187 		break;
188 	default:
189 		break;
190 	}
191 
192 	ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
193 	if (ret != 0) {
194 		dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
195 			ret);
196 		return ret;
197 	}
198 	dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
199 
200 	/* enable VID0 & VID1 */
201 	regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
202 
203 	/* enable/disable external clock synchronization */
204 	info->extclk = pdata->extclk;
205 	data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
206 	regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
207 			   MAX8649_SYNC_EXTCLK, data);
208 	if (info->extclk) {
209 		/* set external clock frequency */
210 		info->extclk_freq = pdata->extclk_freq;
211 		regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
212 				   info->extclk_freq << 6);
213 	}
214 
215 	if (pdata->ramp_timing) {
216 		info->ramp_timing = pdata->ramp_timing;
217 		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
218 				   info->ramp_timing << 5);
219 	}
220 
221 	info->ramp_down = pdata->ramp_down;
222 	if (info->ramp_down) {
223 		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
224 				   MAX8649_RAMP_DOWN);
225 	}
226 
227 	config.dev = &client->dev;
228 	config.init_data = pdata->regulator;
229 	config.driver_data = info;
230 	config.regmap = info->regmap;
231 
232 	regulator = devm_regulator_register(&client->dev, &dcdc_desc,
233 						  &config);
234 	if (IS_ERR(regulator)) {
235 		dev_err(info->dev, "failed to register regulator %s\n",
236 			dcdc_desc.name);
237 		return PTR_ERR(regulator);
238 	}
239 
240 	return 0;
241 }
242 
243 static const struct i2c_device_id max8649_id[] = {
244 	{ "max8649", 0 },
245 	{ }
246 };
247 MODULE_DEVICE_TABLE(i2c, max8649_id);
248 
249 static struct i2c_driver max8649_driver = {
250 	.probe		= max8649_regulator_probe,
251 	.driver		= {
252 		.name	= "max8649",
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