linux/drivers/power/max17040_battery.c
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   1/*
   2 *  max17040_battery.c
   3 *  fuel-gauge systems for lithium-ion (Li+) batteries
   4 *
   5 *  Copyright (C) 2009 Samsung Electronics
   6 *  Minkyu Kang <mk7.kang@samsung.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/init.h>
  15#include <linux/platform_device.h>
  16#include <linux/mutex.h>
  17#include <linux/err.h>
  18#include <linux/i2c.h>
  19#include <linux/delay.h>
  20#include <linux/power_supply.h>
  21#include <linux/max17040_battery.h>
  22
  23#define MAX17040_VCELL_MSB      0x02
  24#define MAX17040_VCELL_LSB      0x03
  25#define MAX17040_SOC_MSB        0x04
  26#define MAX17040_SOC_LSB        0x05
  27#define MAX17040_MODE_MSB       0x06
  28#define MAX17040_MODE_LSB       0x07
  29#define MAX17040_VER_MSB        0x08
  30#define MAX17040_VER_LSB        0x09
  31#define MAX17040_RCOMP_MSB      0x0C
  32#define MAX17040_RCOMP_LSB      0x0D
  33#define MAX17040_CMD_MSB        0xFE
  34#define MAX17040_CMD_LSB        0xFF
  35
  36#define MAX17040_DELAY          1000
  37#define MAX17040_BATTERY_FULL   95
  38
  39struct max17040_chip {
  40        struct i2c_client               *client;
  41        struct delayed_work             work;
  42        struct power_supply             battery;
  43        struct max17040_platform_data   *pdata;
  44
  45        /* State Of Connect */
  46        int online;
  47        /* battery voltage */
  48        int vcell;
  49        /* battery capacity */
  50        int soc;
  51        /* State Of Charge */
  52        int status;
  53};
  54
  55static int max17040_get_property(struct power_supply *psy,
  56                            enum power_supply_property psp,
  57                            union power_supply_propval *val)
  58{
  59        struct max17040_chip *chip = container_of(psy,
  60                                struct max17040_chip, battery);
  61
  62        switch (psp) {
  63        case POWER_SUPPLY_PROP_STATUS:
  64                val->intval = chip->status;
  65                break;
  66        case POWER_SUPPLY_PROP_ONLINE:
  67                val->intval = chip->online;
  68                break;
  69        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  70                val->intval = chip->vcell;
  71                break;
  72        case POWER_SUPPLY_PROP_CAPACITY:
  73                val->intval = chip->soc;
  74                break;
  75        default:
  76                return -EINVAL;
  77        }
  78        return 0;
  79}
  80
  81static int max17040_write_reg(struct i2c_client *client, int reg, u8 value)
  82{
  83        int ret;
  84
  85        ret = i2c_smbus_write_byte_data(client, reg, value);
  86
  87        if (ret < 0)
  88                dev_err(&client->dev, "%s: err %d\n", __func__, ret);
  89
  90        return ret;
  91}
  92
  93static int max17040_read_reg(struct i2c_client *client, int reg)
  94{
  95        int ret;
  96
  97        ret = i2c_smbus_read_byte_data(client, reg);
  98
  99        if (ret < 0)
 100                dev_err(&client->dev, "%s: err %d\n", __func__, ret);
 101
 102        return ret;
 103}
 104
 105static void max17040_reset(struct i2c_client *client)
 106{
 107        max17040_write_reg(client, MAX17040_CMD_MSB, 0x54);
 108        max17040_write_reg(client, MAX17040_CMD_LSB, 0x00);
 109}
 110
 111static void max17040_get_vcell(struct i2c_client *client)
 112{
 113        struct max17040_chip *chip = i2c_get_clientdata(client);
 114        u8 msb;
 115        u8 lsb;
 116
 117        msb = max17040_read_reg(client, MAX17040_VCELL_MSB);
 118        lsb = max17040_read_reg(client, MAX17040_VCELL_LSB);
 119
 120        chip->vcell = (msb << 4) + (lsb >> 4);
 121}
 122
 123static void max17040_get_soc(struct i2c_client *client)
 124{
 125        struct max17040_chip *chip = i2c_get_clientdata(client);
 126        u8 msb;
 127        u8 lsb;
 128
 129        msb = max17040_read_reg(client, MAX17040_SOC_MSB);
 130        lsb = max17040_read_reg(client, MAX17040_SOC_LSB);
 131
 132        chip->soc = msb;
 133}
 134
 135static void max17040_get_version(struct i2c_client *client)
 136{
 137        u8 msb;
 138        u8 lsb;
 139
 140        msb = max17040_read_reg(client, MAX17040_VER_MSB);
 141        lsb = max17040_read_reg(client, MAX17040_VER_LSB);
 142
 143        dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver %d%d\n", msb, lsb);
 144}
 145
 146static void max17040_get_online(struct i2c_client *client)
 147{
 148        struct max17040_chip *chip = i2c_get_clientdata(client);
 149
 150        if (chip->pdata->battery_online)
 151                chip->online = chip->pdata->battery_online();
 152        else
 153                chip->online = 1;
 154}
 155
 156static void max17040_get_status(struct i2c_client *client)
 157{
 158        struct max17040_chip *chip = i2c_get_clientdata(client);
 159
 160        if (!chip->pdata->charger_online || !chip->pdata->charger_enable) {
 161                chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
 162                return;
 163        }
 164
 165        if (chip->pdata->charger_online()) {
 166                if (chip->pdata->charger_enable())
 167                        chip->status = POWER_SUPPLY_STATUS_CHARGING;
 168                else
 169                        chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 170        } else {
 171                chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
 172        }
 173
 174        if (chip->soc > MAX17040_BATTERY_FULL)
 175                chip->status = POWER_SUPPLY_STATUS_FULL;
 176}
 177
 178static void max17040_work(struct work_struct *work)
 179{
 180        struct max17040_chip *chip;
 181
 182        chip = container_of(work, struct max17040_chip, work.work);
 183
 184        max17040_get_vcell(chip->client);
 185        max17040_get_soc(chip->client);
 186        max17040_get_online(chip->client);
 187        max17040_get_status(chip->client);
 188
 189        schedule_delayed_work(&chip->work, MAX17040_DELAY);
 190}
 191
 192static enum power_supply_property max17040_battery_props[] = {
 193        POWER_SUPPLY_PROP_STATUS,
 194        POWER_SUPPLY_PROP_ONLINE,
 195        POWER_SUPPLY_PROP_VOLTAGE_NOW,
 196        POWER_SUPPLY_PROP_CAPACITY,
 197};
 198
 199static int __devinit max17040_probe(struct i2c_client *client,
 200                        const struct i2c_device_id *id)
 201{
 202        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 203        struct max17040_chip *chip;
 204        int ret;
 205
 206        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 207                return -EIO;
 208
 209        chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 210        if (!chip)
 211                return -ENOMEM;
 212
 213        chip->client = client;
 214        chip->pdata = client->dev.platform_data;
 215
 216        i2c_set_clientdata(client, chip);
 217
 218        chip->battery.name              = "battery";
 219        chip->battery.type              = POWER_SUPPLY_TYPE_BATTERY;
 220        chip->battery.get_property      = max17040_get_property;
 221        chip->battery.properties        = max17040_battery_props;
 222        chip->battery.num_properties    = ARRAY_SIZE(max17040_battery_props);
 223
 224        ret = power_supply_register(&client->dev, &chip->battery);
 225        if (ret) {
 226                dev_err(&client->dev, "failed: power supply register\n");
 227                i2c_set_clientdata(client, NULL);
 228                kfree(chip);
 229                return ret;
 230        }
 231
 232        max17040_reset(client);
 233        max17040_get_version(client);
 234
 235        INIT_DELAYED_WORK_DEFERRABLE(&chip->work, max17040_work);
 236        schedule_delayed_work(&chip->work, MAX17040_DELAY);
 237
 238        return 0;
 239}
 240
 241static int __devexit max17040_remove(struct i2c_client *client)
 242{
 243        struct max17040_chip *chip = i2c_get_clientdata(client);
 244
 245        power_supply_unregister(&chip->battery);
 246        cancel_delayed_work(&chip->work);
 247        i2c_set_clientdata(client, NULL);
 248        kfree(chip);
 249        return 0;
 250}
 251
 252#ifdef CONFIG_PM
 253
 254static int max17040_suspend(struct i2c_client *client,
 255                pm_message_t state)
 256{
 257        struct max17040_chip *chip = i2c_get_clientdata(client);
 258
 259        cancel_delayed_work(&chip->work);
 260        return 0;
 261}
 262
 263static int max17040_resume(struct i2c_client *client)
 264{
 265        struct max17040_chip *chip = i2c_get_clientdata(client);
 266
 267        schedule_delayed_work(&chip->work, MAX17040_DELAY);
 268        return 0;
 269}
 270
 271#else
 272
 273#define max17040_suspend NULL
 274#define max17040_resume NULL
 275
 276#endif /* CONFIG_PM */
 277
 278static const struct i2c_device_id max17040_id[] = {
 279        { "max17040", 0 },
 280        { }
 281};
 282MODULE_DEVICE_TABLE(i2c, max17040_id);
 283
 284static struct i2c_driver max17040_i2c_driver = {
 285        .driver = {
 286                .name   = "max17040",
 287        },
 288        .probe          = max17040_probe,
 289        .remove         = __devexit_p(max17040_remove),
 290        .suspend        = max17040_suspend,
 291        .resume         = max17040_resume,
 292        .id_table       = max17040_id,
 293};
 294
 295static int __init max17040_init(void)
 296{
 297        return i2c_add_driver(&max17040_i2c_driver);
 298}
 299module_init(max17040_init);
 300
 301static void __exit max17040_exit(void)
 302{
 303        i2c_del_driver(&max17040_i2c_driver);
 304}
 305module_exit(max17040_exit);
 306
 307MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
 308MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
 309MODULE_LICENSE("GPL");
 310