drivers/power/supply/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  0x02
  25 #define MAX17040_SOC    0x04
  26 #define MAX17040_MODE   0x06
  27 #define MAX17040_VER    0x08
  28 #define MAX17040_RCOMP  0x0C
  29 #define MAX17040_CMD    0xFE
  30
  31
  32 #define MAX17040_DELAY          1000
  33 #define MAX17040_BATTERY_FULL   95
  34
  35 struct max17040_chip {
  36         struct i2c_client               *client;
  37         struct delayed_work             work;
  38         struct power_supply             *battery;
  39         struct max17040_platform_data   *pdata;
  40
  41         /* State Of Connect */
  42         int online;
  43         /* battery voltage */
  44         int vcell;
  45         /* battery capacity */
  46         int soc;
  47         /* State Of Charge */
  48         int status;
  49 };
  50
  51 static int max17040_get_property(struct power_supply *psy,
  52                             enum power_supply_property psp,
  53                             union power_supply_propval *val)
  54 {
  55         struct max17040_chip *chip = power_supply_get_drvdata(psy);
  56
  57         switch (psp) {
  58         case POWER_SUPPLY_PROP_STATUS:
  59                 val->intval = chip->status;
  60                 break;
  61         case POWER_SUPPLY_PROP_ONLINE:
  62                 val->intval = chip->online;
  63                 break;
  64         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  65                 val->intval = chip->vcell;
  66                 break;
  67         case POWER_SUPPLY_PROP_CAPACITY:
  68                 val->intval = chip->soc;
  69                 break;
  70         default:
  71                 return -EINVAL;
  72         }
  73         return 0;
  74 }
  75
  76 static int max17040_write_reg(struct i2c_client *client, int reg, u16 value)
  77 {
  78         int ret;
  79
  80         ret = i2c_smbus_write_word_swapped(client, reg, value);
  81
  82         if (ret < 0)
  83                 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
  84
  85         return ret;
  86 }
  87
  88 static int max17040_read_reg(struct i2c_client *client, int reg)
  89 {
  90         int ret;
  91
  92         ret = i2c_smbus_read_word_swapped(client, reg);
  93
  94         if (ret < 0)
  95                 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
  96
  97         return ret;
  98 }
  99
 100 static void max17040_reset(struct i2c_client *client)
 101 {
 102         max17040_write_reg(client, MAX17040_CMD, 0x0054);
 103 }
 104
 105 static void max17040_get_vcell(struct i2c_client *client)
 106 {
 107         struct max17040_chip *chip = i2c_get_clientdata(client);
 108         u16 vcell;
 109
 110         vcell = max17040_read_reg(client, MAX17040_VCELL);
 111
 112         chip->vcell = vcell;
 113 }
 114
 115 static void max17040_get_soc(struct i2c_client *client)
 116 {
 117         struct max17040_chip *chip = i2c_get_clientdata(client);
 118         u16 soc;
 119
 120         soc = max17040_read_reg(client, MAX17040_SOC);
 121
 122         chip->soc = (soc >> 8);
 123 }
 124
 125 static void max17040_get_version(struct i2c_client *client)
 126 {
 127         u16 version;
 128
 129         version = max17040_read_reg(client, MAX17040_VER);
 130
 131         dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", version);
 132 }
 133
 134 static void max17040_get_online(struct i2c_client *client)
 135 {
 136         struct max17040_chip *chip = i2c_get_clientdata(client);
 137
 138         if (chip->pdata && chip->pdata->battery_online)
 139                 chip->online = chip->pdata->battery_online();
 140         else
 141                 chip->online = 1;
 142 }
 143
 144 static void max17040_get_status(struct i2c_client *client)
 145 {
 146         struct max17040_chip *chip = i2c_get_clientdata(client);
 147
 148         if (!chip->pdata || !chip->pdata->charger_online
 149                         || !chip->pdata->charger_enable) {
 150                 chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
 151                 return;
 152         }
 153
 154         if (chip->pdata->charger_online()) {
 155                 if (chip->pdata->charger_enable())
 156                         chip->status = POWER_SUPPLY_STATUS_CHARGING;
 157                 else
 158                         chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 159         } else {
 160                 chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
 161         }
 162
 163         if (chip->soc > MAX17040_BATTERY_FULL)
 164                 chip->status = POWER_SUPPLY_STATUS_FULL;
 165 }
 166
 167 static void max17040_work(struct work_struct *work)
 168 {
 169         struct max17040_chip *chip;
 170
 171         chip = container_of(work, struct max17040_chip, work.work);
 172
 173         max17040_get_vcell(chip->client);
 174         max17040_get_soc(chip->client);
 175         max17040_get_online(chip->client);
 176         max17040_get_status(chip->client);
 177
 178         queue_delayed_work(system_power_efficient_wq, &chip->work,
 179                            MAX17040_DELAY);
 180 }
 181
 182 static enum power_supply_property max17040_battery_props[] = {
 183         POWER_SUPPLY_PROP_STATUS,
 184         POWER_SUPPLY_PROP_ONLINE,
 185         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 186         POWER_SUPPLY_PROP_CAPACITY,
 187 };
 188
 189 static const struct power_supply_desc max17040_battery_desc = {
 190         .name           = "battery",
 191         .type           = POWER_SUPPLY_TYPE_BATTERY,
 192         .get_property   = max17040_get_property,
 193         .properties     = max17040_battery_props,
 194         .num_properties = ARRAY_SIZE(max17040_battery_props),
 195 };
 196
 197 static int max17040_probe(struct i2c_client *client,
 198                         const struct i2c_device_id *id)
 199 {
 200         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 201         struct power_supply_config psy_cfg = {};
 202         struct max17040_chip *chip;
 203
 204         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 205                 return -EIO;
 206
 207         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 208         if (!chip)
 209                 return -ENOMEM;
 210
 211         chip->client = client;
 212         chip->pdata = client->dev.platform_data;
 213
 214         i2c_set_clientdata(client, chip);
 215         psy_cfg.drv_data = chip;
 216
 217         chip->battery = power_supply_register(&client->dev,
 218                                 &max17040_battery_desc, &psy_cfg);
 219         if (IS_ERR(chip->battery)) {
 220                 dev_err(&client->dev, "failed: power supply register\n");
 221                 return PTR_ERR(chip->battery);
 222         }
 223
 224         max17040_reset(client);
 225         max17040_get_version(client);
 226
 227         INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
 228         queue_delayed_work(system_power_efficient_wq, &chip->work,
 229                            MAX17040_DELAY);
 230
 231         return 0;
 232 }
 233
 234 static int max17040_remove(struct i2c_client *client)
 235 {
 236         struct max17040_chip *chip = i2c_get_clientdata(client);
 237
 238         power_supply_unregister(chip->battery);
 239         cancel_delayed_work(&chip->work);
 240         return 0;
 241 }
 242
 243 #ifdef CONFIG_PM_SLEEP
 244
 245 static int max17040_suspend(struct device *dev)
 246 {
 247         struct i2c_client *client = to_i2c_client(dev);
 248         struct max17040_chip *chip = i2c_get_clientdata(client);
 249
 250         cancel_delayed_work(&chip->work);
 251         return 0;
 252 }
 253
 254 static int max17040_resume(struct device *dev)
 255 {
 256         struct i2c_client *client = to_i2c_client(dev);
 257         struct max17040_chip *chip = i2c_get_clientdata(client);
 258
 259         queue_delayed_work(system_power_efficient_wq, &chip->work,
 260                            MAX17040_DELAY);
 261         return 0;
 262 }
 263
 264 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
 265 #define MAX17040_PM_OPS (&max17040_pm_ops)
 266
 267 #else
 268
 269 #define MAX17040_PM_OPS NULL
 270
 271 #endif /* CONFIG_PM_SLEEP */
 272
 273 static const struct i2c_device_id max17040_id[] = {
 274         { "max17040" },
 275         { "max77836-battery" },
 276         { }
 277 };
 278 MODULE_DEVICE_TABLE(i2c, max17040_id);
 279
 280 static const struct of_device_id max17040_of_match[] = {
 281         { .compatible = "maxim,max17040" },
 282         { .compatible = "maxim,max77836-battery" },
 283         { },
 284 };
 285 MODULE_DEVICE_TABLE(of, max17040_of_match);
 286
 287 static struct i2c_driver max17040_i2c_driver = {
 288         .driver = {
 289                 .name   = "max17040",
 290                 .of_match_table = max17040_of_match,
 291                 .pm     = MAX17040_PM_OPS,
 292         },
 293         .probe          = max17040_probe,
 294         .remove         = max17040_remove,
 295         .id_table       = max17040_id,
 296 };
 297 module_i2c_driver(max17040_i2c_driver);
 298
 299 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
 300 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
 301 MODULE_LICENSE("GPL");