xref: /openbmc/linux/drivers/regulator/max1586.c (revision b34e08d5)
1 /*
2  * max1586.c  --  Voltage and current regulation for the Maxim 1586
3  *
4  * Copyright (C) 2008 Robert Jarzmik
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20 #include <linux/module.h>
21 #include <linux/err.h>
22 #include <linux/i2c.h>
23 #include <linux/platform_device.h>
24 #include <linux/regulator/driver.h>
25 #include <linux/slab.h>
26 #include <linux/regulator/max1586.h>
27 
28 #define MAX1586_V3_MAX_VSEL 31
29 #define MAX1586_V6_MAX_VSEL 3
30 
31 #define MAX1586_V3_MIN_UV   700000
32 #define MAX1586_V3_MAX_UV  1475000
33 
34 #define MAX1586_V6_MIN_UV        0
35 #define MAX1586_V6_MAX_UV  3000000
36 
37 #define I2C_V3_SELECT (0 << 5)
38 #define I2C_V6_SELECT (1 << 5)
39 
40 struct max1586_data {
41 	struct i2c_client *client;
42 
43 	/* min/max V3 voltage */
44 	unsigned int min_uV;
45 	unsigned int max_uV;
46 
47 	unsigned int v3_curr_sel;
48 	unsigned int v6_curr_sel;
49 };
50 
51 /*
52  * V6 voltage
53  * On I2C bus, sending a "x" byte to the max1586 means :
54  *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
55  * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
56  */
57 static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
58 
59 /*
60  * V3 voltage
61  * On I2C bus, sending a "x" byte to the max1586 means :
62  *   set V3 to 0.700V + (x & 0x1f) * 0.025V
63  * This voltage can be increased by external resistors
64  * R24 and R25=100kOhm as described in the data sheet.
65  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
66  */
67 static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
68 {
69 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
70 
71 	return max1586->v3_curr_sel;
72 }
73 
74 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
75 				      unsigned selector)
76 {
77 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
78 	struct i2c_client *client = max1586->client;
79 	int ret;
80 	u8 v3_prog;
81 
82 	dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
83 		regulator_list_voltage_linear(rdev, selector) / 1000);
84 
85 	v3_prog = I2C_V3_SELECT | (u8) selector;
86 	ret = i2c_smbus_write_byte(client, v3_prog);
87 	if (ret)
88 		return ret;
89 
90 	max1586->v3_curr_sel = selector;
91 
92 	return 0;
93 }
94 
95 static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
96 {
97 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
98 
99 	return max1586->v6_curr_sel;
100 }
101 
102 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
103 				      unsigned int selector)
104 {
105 	struct max1586_data *max1586 = rdev_get_drvdata(rdev);
106 	struct i2c_client *client = max1586->client;
107 	u8 v6_prog;
108 	int ret;
109 
110 	dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
111 		rdev->desc->volt_table[selector] / 1000);
112 
113 	v6_prog = I2C_V6_SELECT | (u8) selector;
114 	ret = i2c_smbus_write_byte(client, v6_prog);
115 	if (ret)
116 		return ret;
117 
118 	max1586->v6_curr_sel = selector;
119 
120 	return 0;
121 }
122 
123 /*
124  * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
125  * the set up value.
126  */
127 static struct regulator_ops max1586_v3_ops = {
128 	.get_voltage_sel = max1586_v3_get_voltage_sel,
129 	.set_voltage_sel = max1586_v3_set_voltage_sel,
130 	.list_voltage = regulator_list_voltage_linear,
131 	.map_voltage = regulator_map_voltage_linear,
132 };
133 
134 static struct regulator_ops max1586_v6_ops = {
135 	.get_voltage_sel = max1586_v6_get_voltage_sel,
136 	.set_voltage_sel = max1586_v6_set_voltage_sel,
137 	.list_voltage = regulator_list_voltage_table,
138 };
139 
140 static struct regulator_desc max1586_reg[] = {
141 	{
142 		.name = "Output_V3",
143 		.id = MAX1586_V3,
144 		.ops = &max1586_v3_ops,
145 		.type = REGULATOR_VOLTAGE,
146 		.n_voltages = MAX1586_V3_MAX_VSEL + 1,
147 		.owner = THIS_MODULE,
148 	},
149 	{
150 		.name = "Output_V6",
151 		.id = MAX1586_V6,
152 		.ops = &max1586_v6_ops,
153 		.type = REGULATOR_VOLTAGE,
154 		.n_voltages = MAX1586_V6_MAX_VSEL + 1,
155 		.volt_table = v6_voltages_uv,
156 		.owner = THIS_MODULE,
157 	},
158 };
159 
160 static int max1586_pmic_probe(struct i2c_client *client,
161 					const struct i2c_device_id *i2c_id)
162 {
163 	struct max1586_platform_data *pdata = dev_get_platdata(&client->dev);
164 	struct regulator_config config = { };
165 	struct max1586_data *max1586;
166 	int i, id;
167 
168 	max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
169 			GFP_KERNEL);
170 	if (!max1586)
171 		return -ENOMEM;
172 
173 	max1586->client = client;
174 
175 	if (!pdata->v3_gain)
176 		return -EINVAL;
177 
178 	max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
179 	max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
180 
181 	/* Set curr_sel to default voltage on power-up */
182 	max1586->v3_curr_sel = 24; /* 1.3V */
183 	max1586->v6_curr_sel = 0;
184 
185 	for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
186 		struct regulator_dev *rdev;
187 
188 		id = pdata->subdevs[i].id;
189 		if (!pdata->subdevs[i].platform_data)
190 			continue;
191 		if (id < MAX1586_V3 || id > MAX1586_V6) {
192 			dev_err(&client->dev, "invalid regulator id %d\n", id);
193 			return -EINVAL;
194 		}
195 
196 		if (id == MAX1586_V3) {
197 			max1586_reg[id].min_uV = max1586->min_uV;
198 			max1586_reg[id].uV_step =
199 					(max1586->max_uV - max1586->min_uV) /
200 					MAX1586_V3_MAX_VSEL;
201 		}
202 
203 		config.dev = &client->dev;
204 		config.init_data = pdata->subdevs[i].platform_data;
205 		config.driver_data = max1586;
206 
207 		rdev = devm_regulator_register(&client->dev,
208 						  &max1586_reg[id], &config);
209 		if (IS_ERR(rdev)) {
210 			dev_err(&client->dev, "failed to register %s\n",
211 				max1586_reg[id].name);
212 			return PTR_ERR(rdev);
213 		}
214 	}
215 
216 	i2c_set_clientdata(client, max1586);
217 	dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
218 	return 0;
219 }
220 
221 static const struct i2c_device_id max1586_id[] = {
222 	{ "max1586", 0 },
223 	{ }
224 };
225 MODULE_DEVICE_TABLE(i2c, max1586_id);
226 
227 static struct i2c_driver max1586_pmic_driver = {
228 	.probe = max1586_pmic_probe,
229 	.driver		= {
230 		.name	= "max1586",
231 		.owner	= THIS_MODULE,
232 	},
233 	.id_table	= max1586_id,
234 };
235 
236 static int __init max1586_pmic_init(void)
237 {
238 	return i2c_add_driver(&max1586_pmic_driver);
239 }
240 subsys_initcall(max1586_pmic_init);
241 
242 static void __exit max1586_pmic_exit(void)
243 {
244 	i2c_del_driver(&max1586_pmic_driver);
245 }
246 module_exit(max1586_pmic_exit);
247 
248 /* Module information */
249 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
250 MODULE_AUTHOR("Robert Jarzmik");
251 MODULE_LICENSE("GPL");
252