Root/drivers/regulator/max1586.c

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
40struct 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    struct regulator_dev *rdev[0];
48};
49
50/*
51 * V6 voltage
52 * On I2C bus, sending a "x" byte to the max1586 means :
53 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
54 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
55 */
56static int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
57
58/*
59 * V3 voltage
60 * On I2C bus, sending a "x" byte to the max1586 means :
61 * set V3 to 0.700V + (x & 0x1f) * 0.025V
62 * This voltage can be increased by external resistors
63 * R24 and R25=100kOhm as described in the data sheet.
64 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
65 */
66static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
67                      unsigned selector)
68{
69    struct max1586_data *max1586 = rdev_get_drvdata(rdev);
70    struct i2c_client *client = max1586->client;
71    u8 v3_prog;
72
73    dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
74        regulator_list_voltage_linear(rdev, selector) / 1000);
75
76    v3_prog = I2C_V3_SELECT | (u8) selector;
77    return i2c_smbus_write_byte(client, v3_prog);
78}
79
80static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
81                      unsigned int selector)
82{
83    struct i2c_client *client = rdev_get_drvdata(rdev);
84    u8 v6_prog;
85
86    dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
87        rdev->desc->volt_table[selector] / 1000);
88
89    v6_prog = I2C_V6_SELECT | (u8) selector;
90    return i2c_smbus_write_byte(client, v6_prog);
91}
92
93/*
94 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
95 * the set up value.
96 */
97static struct regulator_ops max1586_v3_ops = {
98    .set_voltage_sel = max1586_v3_set_voltage_sel,
99    .list_voltage = regulator_list_voltage_linear,
100    .map_voltage = regulator_map_voltage_linear,
101};
102
103static struct regulator_ops max1586_v6_ops = {
104    .set_voltage_sel = max1586_v6_set_voltage_sel,
105    .list_voltage = regulator_list_voltage_table,
106};
107
108static struct regulator_desc max1586_reg[] = {
109    {
110        .name = "Output_V3",
111        .id = MAX1586_V3,
112        .ops = &max1586_v3_ops,
113        .type = REGULATOR_VOLTAGE,
114        .n_voltages = MAX1586_V3_MAX_VSEL + 1,
115        .owner = THIS_MODULE,
116    },
117    {
118        .name = "Output_V6",
119        .id = MAX1586_V6,
120        .ops = &max1586_v6_ops,
121        .type = REGULATOR_VOLTAGE,
122        .n_voltages = MAX1586_V6_MAX_VSEL + 1,
123        .volt_table = v6_voltages_uv,
124        .owner = THIS_MODULE,
125    },
126};
127
128static int __devinit max1586_pmic_probe(struct i2c_client *client,
129                    const struct i2c_device_id *i2c_id)
130{
131    struct regulator_dev **rdev;
132    struct max1586_platform_data *pdata = client->dev.platform_data;
133    struct regulator_config config = { };
134    struct max1586_data *max1586;
135    int i, id, ret = -ENOMEM;
136
137    max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) +
138            sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
139            GFP_KERNEL);
140    if (!max1586)
141        return -ENOMEM;
142
143    max1586->client = client;
144
145    if (!pdata->v3_gain)
146        return -EINVAL;
147
148    max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
149    max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
150
151    rdev = max1586->rdev;
152    for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
153        id = pdata->subdevs[i].id;
154        if (!pdata->subdevs[i].platform_data)
155            continue;
156        if (id < MAX1586_V3 || id > MAX1586_V6) {
157            dev_err(&client->dev, "invalid regulator id %d\n", id);
158            goto err;
159        }
160
161        if (id == MAX1586_V3) {
162            max1586_reg[id].min_uV = max1586->min_uV;
163            max1586_reg[id].uV_step =
164                    (max1586->max_uV - max1586->min_uV) /
165                    MAX1586_V3_MAX_VSEL;
166        }
167
168        config.dev = &client->dev;
169        config.init_data = pdata->subdevs[i].platform_data;
170        config.driver_data = max1586;
171
172        rdev[i] = regulator_register(&max1586_reg[id], &config);
173        if (IS_ERR(rdev[i])) {
174            ret = PTR_ERR(rdev[i]);
175            dev_err(&client->dev, "failed to register %s\n",
176                max1586_reg[id].name);
177            goto err;
178        }
179    }
180
181    i2c_set_clientdata(client, max1586);
182    dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
183    return 0;
184
185err:
186    while (--i >= 0)
187        regulator_unregister(rdev[i]);
188    return ret;
189}
190
191static int __devexit max1586_pmic_remove(struct i2c_client *client)
192{
193    struct max1586_data *max1586 = i2c_get_clientdata(client);
194    int i;
195
196    for (i = 0; i <= MAX1586_V6; i++)
197        if (max1586->rdev[i])
198            regulator_unregister(max1586->rdev[i]);
199    return 0;
200}
201
202static const struct i2c_device_id max1586_id[] = {
203    { "max1586", 0 },
204    { }
205};
206MODULE_DEVICE_TABLE(i2c, max1586_id);
207
208static struct i2c_driver max1586_pmic_driver = {
209    .probe = max1586_pmic_probe,
210    .remove = __devexit_p(max1586_pmic_remove),
211    .driver = {
212        .name = "max1586",
213        .owner = THIS_MODULE,
214    },
215    .id_table = max1586_id,
216};
217
218static int __init max1586_pmic_init(void)
219{
220    return i2c_add_driver(&max1586_pmic_driver);
221}
222subsys_initcall(max1586_pmic_init);
223
224static void __exit max1586_pmic_exit(void)
225{
226    i2c_del_driver(&max1586_pmic_driver);
227}
228module_exit(max1586_pmic_exit);
229
230/* Module information */
231MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
232MODULE_AUTHOR("Robert Jarzmik");
233MODULE_LICENSE("GPL");
234

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