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 regulator_dev	*rdev[3];
35 	struct mutex		mtx;
36 };
37 
38 static int isl6271a_get_voltage_sel(struct regulator_dev *dev)
39 {
40 	struct isl_pmic *pmic = rdev_get_drvdata(dev);
41 	int idx;
42 
43 	mutex_lock(&pmic->mtx);
44 
45 	idx = i2c_smbus_read_byte(pmic->client);
46 	if (idx < 0)
47 		dev_err(&pmic->client->dev, "Error getting voltage\n");
48 
49 	mutex_unlock(&pmic->mtx);
50 	return idx;
51 }
52 
53 static int isl6271a_set_voltage_sel(struct regulator_dev *dev,
54 				    unsigned selector)
55 {
56 	struct isl_pmic *pmic = rdev_get_drvdata(dev);
57 	int err;
58 
59 	mutex_lock(&pmic->mtx);
60 
61 	err = i2c_smbus_write_byte(pmic->client, selector);
62 	if (err < 0)
63 		dev_err(&pmic->client->dev, "Error setting voltage\n");
64 
65 	mutex_unlock(&pmic->mtx);
66 	return err;
67 }
68 
69 static struct regulator_ops isl_core_ops = {
70 	.get_voltage_sel = isl6271a_get_voltage_sel,
71 	.set_voltage_sel = isl6271a_set_voltage_sel,
72 	.list_voltage	= regulator_list_voltage_linear,
73 	.map_voltage	= regulator_map_voltage_linear,
74 };
75 
76 static struct regulator_ops isl_fixed_ops = {
77 	.list_voltage	= regulator_list_voltage_linear,
78 };
79 
80 static const struct regulator_desc isl_rd[] = {
81 	{
82 		.name		= "Core Buck",
83 		.id		= 0,
84 		.n_voltages	= 16,
85 		.ops		= &isl_core_ops,
86 		.type		= REGULATOR_VOLTAGE,
87 		.owner		= THIS_MODULE,
88 		.min_uV		= ISL6271A_VOLTAGE_MIN,
89 		.uV_step	= ISL6271A_VOLTAGE_STEP,
90 	}, {
91 		.name		= "LDO1",
92 		.id		= 1,
93 		.n_voltages	= 1,
94 		.ops		= &isl_fixed_ops,
95 		.type		= REGULATOR_VOLTAGE,
96 		.owner		= THIS_MODULE,
97 		.min_uV		= 1100000,
98 	}, {
99 		.name		= "LDO2",
100 		.id		= 2,
101 		.n_voltages	= 1,
102 		.ops		= &isl_fixed_ops,
103 		.type		= REGULATOR_VOLTAGE,
104 		.owner		= THIS_MODULE,
105 		.min_uV		= 1300000,
106 	},
107 };
108 
109 static int isl6271a_probe(struct i2c_client *i2c,
110 				     const struct i2c_device_id *id)
111 {
112 	struct regulator_config config = { };
113 	struct regulator_init_data *init_data	= i2c->dev.platform_data;
114 	struct isl_pmic *pmic;
115 	int err, 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 		pmic->rdev[i] = regulator_register(&isl_rd[i], &config);
137 		if (IS_ERR(pmic->rdev[i])) {
138 			dev_err(&i2c->dev, "failed to register %s\n", id->name);
139 			err = PTR_ERR(pmic->rdev[i]);
140 			goto error;
141 		}
142 	}
143 
144 	i2c_set_clientdata(i2c, pmic);
145 
146 	return 0;
147 
148 error:
149 	while (--i >= 0)
150 		regulator_unregister(pmic->rdev[i]);
151 	return err;
152 }
153 
154 static int isl6271a_remove(struct i2c_client *i2c)
155 {
156 	struct isl_pmic *pmic = i2c_get_clientdata(i2c);
157 	int i;
158 
159 	for (i = 0; i < 3; i++)
160 		regulator_unregister(pmic->rdev[i]);
161 	return 0;
162 }
163 
164 static const struct i2c_device_id isl6271a_id[] = {
165 	{.name = "isl6271a", 0 },
166 	{ },
167 };
168 
169 MODULE_DEVICE_TABLE(i2c, isl6271a_id);
170 
171 static struct i2c_driver isl6271a_i2c_driver = {
172 	.driver = {
173 		.name = "isl6271a",
174 		.owner = THIS_MODULE,
175 	},
176 	.probe = isl6271a_probe,
177 	.remove = isl6271a_remove,
178 	.id_table = isl6271a_id,
179 };
180 
181 static int __init isl6271a_init(void)
182 {
183 	return i2c_add_driver(&isl6271a_i2c_driver);
184 }
185 
186 static void __exit isl6271a_cleanup(void)
187 {
188 	i2c_del_driver(&isl6271a_i2c_driver);
189 }
190 
191 subsys_initcall(isl6271a_init);
192 module_exit(isl6271a_cleanup);
193 
194 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
195 MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
196 MODULE_LICENSE("GPL v2");
197