1 /*
2  * isl6271a-regulator.c
3  *
4  * Support for Intersil ISL6271A voltage regulator
5  *
6  * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation version 2.
11  *
12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
13  * whether express or implied; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/err.h>
22 #include <linux/platform_device.h>
23 #include <linux/regulator/driver.h>
24 #include <linux/i2c.h>
25 #include <linux/slab.h>
26 
27 #define	ISL6271A_VOLTAGE_MIN	850000
28 #define	ISL6271A_VOLTAGE_MAX	1600000
29 #define	ISL6271A_VOLTAGE_STEP	50000
30 
31 /* PMIC details */
32 struct isl_pmic {
33 	struct i2c_client	*client;
34 	struct mutex		mtx;
35 };
36 
37 static int isl6271a_get_voltage_sel(struct regulator_dev *dev)
38 {
39 	struct isl_pmic *pmic = rdev_get_drvdata(dev);
40 	int idx;
41 
42 	mutex_lock(&pmic->mtx);
43 
44 	idx = i2c_smbus_read_byte(pmic->client);
45 	if (idx < 0)
46 		dev_err(&pmic->client->dev, "Error getting voltage\n");
47 
48 	mutex_unlock(&pmic->mtx);
49 	return idx;
50 }
51 
52 static int isl6271a_set_voltage_sel(struct regulator_dev *dev,
53 				    unsigned selector)
54 {
55 	struct isl_pmic *pmic = rdev_get_drvdata(dev);
56 	int err;
57 
58 	mutex_lock(&pmic->mtx);
59 
60 	err = i2c_smbus_write_byte(pmic->client, selector);
61 	if (err < 0)
62 		dev_err(&pmic->client->dev, "Error setting voltage\n");
63 
64 	mutex_unlock(&pmic->mtx);
65 	return err;
66 }
67 
68 static const struct regulator_ops isl_core_ops = {
69 	.get_voltage_sel = isl6271a_get_voltage_sel,
70 	.set_voltage_sel = isl6271a_set_voltage_sel,
71 	.list_voltage	= regulator_list_voltage_linear,
72 	.map_voltage	= regulator_map_voltage_linear,
73 };
74 
75 static const struct regulator_ops isl_fixed_ops = {
76 	.list_voltage	= regulator_list_voltage_linear,
77 };
78 
79 static const struct regulator_desc isl_rd[] = {
80 	{
81 		.name		= "Core Buck",
82 		.id		= 0,
83 		.n_voltages	= 16,
84 		.ops		= &isl_core_ops,
85 		.type		= REGULATOR_VOLTAGE,
86 		.owner		= THIS_MODULE,
87 		.min_uV		= ISL6271A_VOLTAGE_MIN,
88 		.uV_step	= ISL6271A_VOLTAGE_STEP,
89 	}, {
90 		.name		= "LDO1",
91 		.id		= 1,
92 		.n_voltages	= 1,
93 		.ops		= &isl_fixed_ops,
94 		.type		= REGULATOR_VOLTAGE,
95 		.owner		= THIS_MODULE,
96 		.min_uV		= 1100000,
97 	}, {
98 		.name		= "LDO2",
99 		.id		= 2,
100 		.n_voltages	= 1,
101 		.ops		= &isl_fixed_ops,
102 		.type		= REGULATOR_VOLTAGE,
103 		.owner		= THIS_MODULE,
104 		.min_uV		= 1300000,
105 	},
106 };
107 
108 static int isl6271a_probe(struct i2c_client *i2c,
109 				     const struct i2c_device_id *id)
110 {
111 	struct regulator_dev *rdev;
112 	struct regulator_config config = { };
113 	struct regulator_init_data *init_data	= dev_get_platdata(&i2c->dev);
114 	struct isl_pmic *pmic;
115 	int i;
116 
117 	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
118 		return -EIO;
119 
120 	pmic = devm_kzalloc(&i2c->dev, sizeof(struct isl_pmic), GFP_KERNEL);
121 	if (!pmic)
122 		return -ENOMEM;
123 
124 	pmic->client = i2c;
125 
126 	mutex_init(&pmic->mtx);
127 
128 	for (i = 0; i < 3; i++) {
129 		config.dev = &i2c->dev;
130 		if (i == 0)
131 			config.init_data = init_data;
132 		else
133 			config.init_data = NULL;
134 		config.driver_data = pmic;
135 
136 		rdev = devm_regulator_register(&i2c->dev, &isl_rd[i], &config);
137 		if (IS_ERR(rdev)) {
138 			dev_err(&i2c->dev, "failed to register %s\n", id->name);
139 			return PTR_ERR(rdev);
140 		}
141 	}
142 
143 	i2c_set_clientdata(i2c, pmic);
144 
145 	return 0;
146 }
147 
148 static const struct i2c_device_id isl6271a_id[] = {
149 	{.name = "isl6271a", 0 },
150 	{ },
151 };
152 
153 MODULE_DEVICE_TABLE(i2c, isl6271a_id);
154 
155 static struct i2c_driver isl6271a_i2c_driver = {
156 	.driver = {
157 		.name = "isl6271a",
158 	},
159 	.probe = isl6271a_probe,
160 	.id_table = isl6271a_id,
161 };
162 
163 static int __init isl6271a_init(void)
164 {
165 	return i2c_add_driver(&isl6271a_i2c_driver);
166 }
167 
168 static void __exit isl6271a_cleanup(void)
169 {
170 	i2c_del_driver(&isl6271a_i2c_driver);
171 }
172 
173 subsys_initcall(isl6271a_init);
174 module_exit(isl6271a_cleanup);
175 
176 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
177 MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
178 MODULE_LICENSE("GPL v2");
179