linux/drivers/regulator/max1586.c
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   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        unsigned int v3_curr_sel;
  48        unsigned int v6_curr_sel;
  49
  50        struct regulator_dev *rdev[0];
  51};
  52
  53/*
  54 * V6 voltage
  55 * On I2C bus, sending a "x" byte to the max1586 means :
  56 *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
  57 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
  58 */
  59static int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
  60
  61/*
  62 * V3 voltage
  63 * On I2C bus, sending a "x" byte to the max1586 means :
  64 *   set V3 to 0.700V + (x & 0x1f) * 0.025V
  65 * This voltage can be increased by external resistors
  66 * R24 and R25=100kOhm as described in the data sheet.
  67 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  68 */
  69static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
  70{
  71        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  72
  73        return max1586->v3_curr_sel;
  74}
  75
  76static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
  77                                      unsigned selector)
  78{
  79        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  80        struct i2c_client *client = max1586->client;
  81        int ret;
  82        u8 v3_prog;
  83
  84        dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
  85                regulator_list_voltage_linear(rdev, selector) / 1000);
  86
  87        v3_prog = I2C_V3_SELECT | (u8) selector;
  88        ret = i2c_smbus_write_byte(client, v3_prog);
  89        if (ret)
  90                return ret;
  91
  92        max1586->v3_curr_sel = selector;
  93
  94        return 0;
  95}
  96
  97static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
  98{
  99        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
 100
 101        return max1586->v6_curr_sel;
 102}
 103
 104static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
 105                                      unsigned int selector)
 106{
 107        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
 108        struct i2c_client *client = max1586->client;
 109        u8 v6_prog;
 110        int ret;
 111
 112        dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
 113                rdev->desc->volt_table[selector] / 1000);
 114
 115        v6_prog = I2C_V6_SELECT | (u8) selector;
 116        ret = i2c_smbus_write_byte(client, v6_prog);
 117        if (ret)
 118                return ret;
 119
 120        max1586->v6_curr_sel = selector;
 121
 122        return 0;
 123}
 124
 125/*
 126 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
 127 * the set up value.
 128 */
 129static struct regulator_ops max1586_v3_ops = {
 130        .get_voltage_sel = max1586_v3_get_voltage_sel,
 131        .set_voltage_sel = max1586_v3_set_voltage_sel,
 132        .list_voltage = regulator_list_voltage_linear,
 133        .map_voltage = regulator_map_voltage_linear,
 134};
 135
 136static struct regulator_ops max1586_v6_ops = {
 137        .get_voltage_sel = max1586_v6_get_voltage_sel,
 138        .set_voltage_sel = max1586_v6_set_voltage_sel,
 139        .list_voltage = regulator_list_voltage_table,
 140};
 141
 142static struct regulator_desc max1586_reg[] = {
 143        {
 144                .name = "Output_V3",
 145                .id = MAX1586_V3,
 146                .ops = &max1586_v3_ops,
 147                .type = REGULATOR_VOLTAGE,
 148                .n_voltages = MAX1586_V3_MAX_VSEL + 1,
 149                .owner = THIS_MODULE,
 150        },
 151        {
 152                .name = "Output_V6",
 153                .id = MAX1586_V6,
 154                .ops = &max1586_v6_ops,
 155                .type = REGULATOR_VOLTAGE,
 156                .n_voltages = MAX1586_V6_MAX_VSEL + 1,
 157                .volt_table = v6_voltages_uv,
 158                .owner = THIS_MODULE,
 159        },
 160};
 161
 162static int max1586_pmic_probe(struct i2c_client *client,
 163                                        const struct i2c_device_id *i2c_id)
 164{
 165        struct regulator_dev **rdev;
 166        struct max1586_platform_data *pdata = client->dev.platform_data;
 167        struct regulator_config config = { };
 168        struct max1586_data *max1586;
 169        int i, id, ret = -ENOMEM;
 170
 171        max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) +
 172                        sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
 173                        GFP_KERNEL);
 174        if (!max1586)
 175                return -ENOMEM;
 176
 177        max1586->client = client;
 178
 179        if (!pdata->v3_gain)
 180                return -EINVAL;
 181
 182        max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 183        max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 184
 185        /* Set curr_sel to default voltage on power-up */
 186        max1586->v3_curr_sel = 24; /* 1.3V */
 187        max1586->v6_curr_sel = 0;
 188
 189        rdev = max1586->rdev;
 190        for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 191                id = pdata->subdevs[i].id;
 192                if (!pdata->subdevs[i].platform_data)
 193                        continue;
 194                if (id < MAX1586_V3 || id > MAX1586_V6) {
 195                        dev_err(&client->dev, "invalid regulator id %d\n", id);
 196                        goto err;
 197                }
 198
 199                if (id == MAX1586_V3) {
 200                        max1586_reg[id].min_uV = max1586->min_uV;
 201                        max1586_reg[id].uV_step =
 202                                        (max1586->max_uV - max1586->min_uV) /
 203                                        MAX1586_V3_MAX_VSEL;
 204                }
 205
 206                config.dev = &client->dev;
 207                config.init_data = pdata->subdevs[i].platform_data;
 208                config.driver_data = max1586;
 209
 210                rdev[i] = regulator_register(&max1586_reg[id], &config);
 211                if (IS_ERR(rdev[i])) {
 212                        ret = PTR_ERR(rdev[i]);
 213                        dev_err(&client->dev, "failed to register %s\n",
 214                                max1586_reg[id].name);
 215                        goto err;
 216                }
 217        }
 218
 219        i2c_set_clientdata(client, max1586);
 220        dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 221        return 0;
 222
 223err:
 224        while (--i >= 0)
 225                regulator_unregister(rdev[i]);
 226        return ret;
 227}
 228
 229static int max1586_pmic_remove(struct i2c_client *client)
 230{
 231        struct max1586_data *max1586 = i2c_get_clientdata(client);
 232        int i;
 233
 234        for (i = 0; i <= MAX1586_V6; i++)
 235                if (max1586->rdev[i])
 236                        regulator_unregister(max1586->rdev[i]);
 237        return 0;
 238}
 239
 240static const struct i2c_device_id max1586_id[] = {
 241        { "max1586", 0 },
 242        { }
 243};
 244MODULE_DEVICE_TABLE(i2c, max1586_id);
 245
 246static struct i2c_driver max1586_pmic_driver = {
 247        .probe = max1586_pmic_probe,
 248        .remove = max1586_pmic_remove,
 249        .driver         = {
 250                .name   = "max1586",
 251                .owner  = THIS_MODULE,
 252        },
 253        .id_table       = max1586_id,
 254};
 255
 256static int __init max1586_pmic_init(void)
 257{
 258        return i2c_add_driver(&max1586_pmic_driver);
 259}
 260subsys_initcall(max1586_pmic_init);
 261
 262static void __exit max1586_pmic_exit(void)
 263{
 264        i2c_del_driver(&max1586_pmic_driver);
 265}
 266module_exit(max1586_pmic_exit);
 267
 268/* Module information */
 269MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 270MODULE_AUTHOR("Robert Jarzmik");
 271MODULE_LICENSE("GPL");
 272
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