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 
51 struct 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 
max8649_enable_time(struct regulator_dev * rdev)62 static 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 
max8649_set_mode(struct regulator_dev * rdev,unsigned int mode)85 static 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 
max8649_get_mode(struct regulator_dev * rdev)104 static 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 
118 static 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 
132 static 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 
146 static const struct regmap_config max8649_regmap_config = {
147 	.reg_bits = 8,
148 	.val_bits = 8,
149 };
150 
max8649_regulator_probe(struct i2c_client * client,const struct i2c_device_id * id)151 static 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 
246 static const struct i2c_device_id max8649_id[] = {
247 	{ "max8649", 0 },
248 	{ }
249 };
250 MODULE_DEVICE_TABLE(i2c, max8649_id);
251 
252 static struct i2c_driver max8649_driver = {
253 	.probe		= max8649_regulator_probe,
254 	.driver		= {
255 		.name	= "max8649",
256 	},
257 	.id_table	= max8649_id,
258 };
259 
max8649_init(void)260 static int __init max8649_init(void)
261 {
262 	return i2c_add_driver(&max8649_driver);
263 }
264 subsys_initcall(max8649_init);
265 
max8649_exit(void)266 static void __exit max8649_exit(void)
267 {
268 	i2c_del_driver(&max8649_driver);
269 }
270 module_exit(max8649_exit);
271 
272 /* Module information */
273 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
274 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
275 MODULE_LICENSE("GPL");
276