drivers/power/max17040_battery.c

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