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 = power_supply_get_drvdata(psy);
  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
  81 static 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
  93 static 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
 105 static 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
 111 static 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
 123 static 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
 135 static 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
 146 static void max17040_get_online(struct i2c_client *client)
 147 {
 148         struct max17040_chip *chip = i2c_get_clientdata(client);
 149
 150         if (chip->pdata && chip->pdata->battery_online)
 151                 chip->online = chip->pdata->battery_online();
 152         else
 153                 chip->online = 1;
 154 }
 155
 156 static void max17040_get_status(struct i2c_client *client)
 157 {
 158         struct max17040_chip *chip = i2c_get_clientdata(client);
 159
 160         if (!chip->pdata || !chip->pdata->charger_online
 161                         || !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         queue_delayed_work(system_power_efficient_wq, &chip->work,
 191                            MAX17040_DELAY);
 192 }
 193
 194 static enum power_supply_property max17040_battery_props[] = {
 195         POWER_SUPPLY_PROP_STATUS,
 196         POWER_SUPPLY_PROP_ONLINE,
 197         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 198         POWER_SUPPLY_PROP_CAPACITY,
 199 };
 200
 201 static const struct power_supply_desc max17040_battery_desc = {
 202         .name           = "battery",
 203         .type           = POWER_SUPPLY_TYPE_BATTERY,
 204         .get_property   = max17040_get_property,
 205         .properties     = max17040_battery_props,
 206         .num_properties = ARRAY_SIZE(max17040_battery_props),
 207 };
 208
 209 static int max17040_probe(struct i2c_client *client,
 210                         const struct i2c_device_id *id)
 211 {
 212         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 213         struct power_supply_config psy_cfg = {};
 214         struct max17040_chip *chip;
 215
 216         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 217                 return -EIO;
 218
 219         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 220         if (!chip)
 221                 return -ENOMEM;
 222
 223         chip->client = client;
 224         chip->pdata = client->dev.platform_data;
 225
 226         i2c_set_clientdata(client, chip);
 227         psy_cfg.drv_data = chip;
 228
 229         chip->battery = power_supply_register(&client->dev,
 230                                 &max17040_battery_desc, &psy_cfg);
 231         if (IS_ERR(chip->battery)) {
 232                 dev_err(&client->dev, "failed: power supply register\n");
 233                 return PTR_ERR(chip->battery);
 234         }
 235
 236         max17040_reset(client);
 237         max17040_get_version(client);
 238
 239         INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
 240         queue_delayed_work(system_power_efficient_wq, &chip->work,
 241                            MAX17040_DELAY);
 242
 243         return 0;
 244 }
 245
 246 static int max17040_remove(struct i2c_client *client)
 247 {
 248         struct max17040_chip *chip = i2c_get_clientdata(client);
 249
 250         power_supply_unregister(chip->battery);
 251         cancel_delayed_work(&chip->work);
 252         return 0;
 253 }
 254
 255 #ifdef CONFIG_PM_SLEEP
 256
 257 static int max17040_suspend(struct device *dev)
 258 {
 259         struct i2c_client *client = to_i2c_client(dev);
 260         struct max17040_chip *chip = i2c_get_clientdata(client);
 261
 262         cancel_delayed_work(&chip->work);
 263         return 0;
 264 }
 265
 266 static int max17040_resume(struct device *dev)
 267 {
 268         struct i2c_client *client = to_i2c_client(dev);
 269         struct max17040_chip *chip = i2c_get_clientdata(client);
 270
 271         queue_delayed_work(system_power_efficient_wq, &chip->work,
 272                            MAX17040_DELAY);
 273         return 0;
 274 }
 275
 276 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
 277 #define MAX17040_PM_OPS (&max17040_pm_ops)
 278
 279 #else
 280
 281 #define MAX17040_PM_OPS NULL
 282
 283 #endif /* CONFIG_PM_SLEEP */
 284
 285 static const struct i2c_device_id max17040_id[] = {
 286         { "max17040" },
 287         { "max77836-battery" },
 288         { }
 289 };
 290 MODULE_DEVICE_TABLE(i2c, max17040_id);
 291
 292 static struct i2c_driver max17040_i2c_driver = {
 293         .driver = {
 294                 .name   = "max17040",
 295                 .pm     = MAX17040_PM_OPS,
 296         },
 297         .probe          = max17040_probe,
 298         .remove         = max17040_remove,
 299         .id_table       = max17040_id,
 300 };
 301 module_i2c_driver(max17040_i2c_driver);
 302
 303 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
 304 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
 305 MODULE_LICENSE("GPL");