LXR linux/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 * V3 voltage
  52 * On I2C bus, sending a "x" byte to the max1586 means :
  53 *   set V3 to 0.700V + (x & 0x1f) * 0.025V
  54 * This voltage can be increased by external resistors
  55 * R24 and R25=100kOhm as described in the data sheet.
  56 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  57 */
  58static int max1586_v3_calc_voltage(struct max1586_data *max1586,
  59        unsigned selector)
  60{
  61        unsigned range_uV = max1586->max_uV - max1586->min_uV;
  62
  63        return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL);
  64}
  65
  66static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV,
  67                          unsigned *selector)
  68{
  69        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  70        struct i2c_client *client = max1586->client;
  71        unsigned range_uV = max1586->max_uV - max1586->min_uV;
  72        u8 v3_prog;
  73
  74        if (min_uV > max1586->max_uV || max_uV < max1586->min_uV)
  75                return -EINVAL;
  76        if (min_uV < max1586->min_uV)
  77                min_uV = max1586->min_uV;
  78
  79        *selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL +
  80                        range_uV - 1) / range_uV;
  81        if (max1586_v3_calc_voltage(max1586, *selector) > max_uV)
  82                return -EINVAL;
  83
  84        dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
  85                max1586_v3_calc_voltage(max1586, *selector) / 1000);
  86
  87        v3_prog = I2C_V3_SELECT | (u8) *selector;
  88        return i2c_smbus_write_byte(client, v3_prog);
  89}
  90
  91static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector)
  92{
  93        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  94
  95        if (selector > MAX1586_V3_MAX_VSEL)
  96                return -EINVAL;
  97        return max1586_v3_calc_voltage(max1586, selector);
  98}
  99
 100/*
 101 * V6 voltage
 102 * On I2C bus, sending a "x" byte to the max1586 means :
 103 *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
 104 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
 105 */
 106static int max1586_v6_calc_voltage(unsigned selector)
 107{
 108        static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
 109
 110        return voltages_uv[selector];
 111}
 112
 113static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV,
 114                          unsigned int *selector)
 115{
 116        struct i2c_client *client = rdev_get_drvdata(rdev);
 117        u8 v6_prog;
 118
 119        if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV)
 120                return -EINVAL;
 121        if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV)
 122                return -EINVAL;
 123
 124        if (min_uV < 1800000)
 125                *selector = 0;
 126        else if (min_uV < 2500000)
 127                *selector = 1;
 128        else if (min_uV < 3000000)
 129                *selector = 2;
 130        else if (min_uV >= 3000000)
 131                *selector = 3;
 132
 133        if (max1586_v6_calc_voltage(*selector) > max_uV)
 134                return -EINVAL;
 135
 136        dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
 137                max1586_v6_calc_voltage(*selector) / 1000);
 138
 139        v6_prog = I2C_V6_SELECT | (u8) *selector;
 140        return i2c_smbus_write_byte(client, v6_prog);
 141}
 142
 143static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector)
 144{
 145        if (selector > MAX1586_V6_MAX_VSEL)
 146                return -EINVAL;
 147        return max1586_v6_calc_voltage(selector);
 148}
 149
 150/*
 151 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
 152 * the set up value.
 153 */
 154static struct regulator_ops max1586_v3_ops = {
 155        .set_voltage = max1586_v3_set,
 156        .list_voltage = max1586_v3_list,
 157};
 158
 159static struct regulator_ops max1586_v6_ops = {
 160        .set_voltage = max1586_v6_set,
 161        .list_voltage = max1586_v6_list,
 162};
 163
 164static struct regulator_desc max1586_reg[] = {
 165        {
 166                .name = "Output_V3",
 167                .id = MAX1586_V3,
 168                .ops = &max1586_v3_ops,
 169                .type = REGULATOR_VOLTAGE,
 170                .n_voltages = MAX1586_V3_MAX_VSEL + 1,
 171                .owner = THIS_MODULE,
 172        },
 173        {
 174                .name = "Output_V6",
 175                .id = MAX1586_V6,
 176                .ops = &max1586_v6_ops,
 177                .type = REGULATOR_VOLTAGE,
 178                .n_voltages = MAX1586_V6_MAX_VSEL + 1,
 179                .owner = THIS_MODULE,
 180        },
 181};
 182
 183static int __devinit max1586_pmic_probe(struct i2c_client *client,
 184                                        const struct i2c_device_id *i2c_id)
 185{
 186        struct regulator_dev **rdev;
 187        struct max1586_platform_data *pdata = client->dev.platform_data;
 188        struct max1586_data *max1586;
 189        int i, id, ret = -ENOMEM;
 190
 191        max1586 = kzalloc(sizeof(struct max1586_data) +
 192                        sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
 193                        GFP_KERNEL);
 194        if (!max1586)
 195                goto out;
 196
 197        max1586->client = client;
 198
 199        if (!pdata->v3_gain) {
 200                ret = -EINVAL;
 201                goto out_unmap;
 202        }
 203        max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 204        max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 205
 206        rdev = max1586->rdev;
 207        for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 208                id = pdata->subdevs[i].id;
 209                if (!pdata->subdevs[i].platform_data)
 210                        continue;
 211                if (id < MAX1586_V3 || id > MAX1586_V6) {
 212                        dev_err(&client->dev, "invalid regulator id %d\n", id);
 213                        goto err;
 214                }
 215                rdev[i] = regulator_register(&max1586_reg[id], &client->dev,
 216                                             pdata->subdevs[i].platform_data,
 217                                             max1586, NULL);
 218                if (IS_ERR(rdev[i])) {
 219                        ret = PTR_ERR(rdev[i]);
 220                        dev_err(&client->dev, "failed to register %s\n",
 221                                max1586_reg[id].name);
 222                        goto err;
 223                }
 224        }
 225
 226        i2c_set_clientdata(client, max1586);
 227        dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 228        return 0;
 229
 230err:
 231        while (--i >= 0)
 232                regulator_unregister(rdev[i]);
 233out_unmap:
 234        kfree(max1586);
 235out:
 236        return ret;
 237}
 238
 239static int __devexit max1586_pmic_remove(struct i2c_client *client)
 240{
 241        struct max1586_data *max1586 = i2c_get_clientdata(client);
 242        int i;
 243
 244        for (i = 0; i <= MAX1586_V6; i++)
 245                if (max1586->rdev[i])
 246                        regulator_unregister(max1586->rdev[i]);
 247        kfree(max1586);
 248
 249        return 0;
 250}
 251
 252static const struct i2c_device_id max1586_id[] = {
 253        { "max1586", 0 },
 254        { }
 255};
 256MODULE_DEVICE_TABLE(i2c, max1586_id);
 257
 258static struct i2c_driver max1586_pmic_driver = {
 259        .probe = max1586_pmic_probe,
 260        .remove = __devexit_p(max1586_pmic_remove),
 261        .driver         = {
 262                .name   = "max1586",
 263                .owner  = THIS_MODULE,
 264        },
 265        .id_table       = max1586_id,
 266};
 267
 268static int __init max1586_pmic_init(void)
 269{
 270        return i2c_add_driver(&max1586_pmic_driver);
 271}
 272subsys_initcall(max1586_pmic_init);
 273
 274static void __exit max1586_pmic_exit(void)
 275{
 276        i2c_del_driver(&max1586_pmic_driver);
 277}
 278module_exit(max1586_pmic_exit);
 279
 280/* Module information */
 281MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 282MODULE_AUTHOR("Robert Jarzmik");
 283MODULE_LICENSE("GPL");
 284