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 40struct 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 56static 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 82static 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 94static 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 106static 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 112static 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 124static 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 136static 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 147static void max17040_get_online(struct i2c_client *client) 148{ 149 struct max17040_chip *chip = i2c_get_clientdata(client); 150 151 if (chip->pdata && chip->pdata->battery_online) 152 chip->online = chip->pdata->battery_online(); 153 else 154 chip->online = 1; 155} 156 157static void max17040_get_status(struct i2c_client *client) 158{ 159 struct max17040_chip *chip = i2c_get_clientdata(client); 160 161 if (!chip->pdata || !chip->pdata->charger_online 162 || !chip->pdata->charger_enable) { 163 chip->status = POWER_SUPPLY_STATUS_UNKNOWN; 164 return; 165 } 166 167 if (chip->pdata->charger_online()) { 168 if (chip->pdata->charger_enable()) 169 chip->status = POWER_SUPPLY_STATUS_CHARGING; 170 else 171 chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING; 172 } else { 173 chip->status = POWER_SUPPLY_STATUS_DISCHARGING; 174 } 175 176 if (chip->soc > MAX17040_BATTERY_FULL) 177 chip->status = POWER_SUPPLY_STATUS_FULL; 178} 179 180static void max17040_work(struct work_struct *work) 181{ 182 struct max17040_chip *chip; 183 184 chip = container_of(work, struct max17040_chip, work.work); 185 186 max17040_get_vcell(chip->client); 187 max17040_get_soc(chip->client); 188 max17040_get_online(chip->client); 189 max17040_get_status(chip->client); 190 191 schedule_delayed_work(&chip->work, MAX17040_DELAY); 192} 193 194static 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 201static int max17040_probe(struct i2c_client *client, 202 const struct i2c_device_id *id) 203{ 204 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 205 struct max17040_chip *chip; 206 int ret; 207 208 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 209 return -EIO; 210 211 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 212 if (!chip) 213 return -ENOMEM; 214 215 chip->client = client; 216 chip->pdata = client->dev.platform_data; 217 218 i2c_set_clientdata(client, chip); 219 220 chip->battery.name = "battery"; 221 chip->battery.type = POWER_SUPPLY_TYPE_BATTERY; 222 chip->battery.get_property = max17040_get_property; 223 chip->battery.properties = max17040_battery_props; 224 chip->battery.num_properties = ARRAY_SIZE(max17040_battery_props); 225 226 ret = power_supply_register(&client->dev, &chip->battery); 227 if (ret) { 228 dev_err(&client->dev, "failed: power supply register\n"); 229 return ret; 230 } 231 232 max17040_reset(client); 233 max17040_get_version(client); 234 235 INIT_DEFERRABLE_WORK(&chip->work, max17040_work); 236 schedule_delayed_work(&chip->work, MAX17040_DELAY); 237 238 return 0; 239} 240 241static int 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 return 0; 248} 249 250#ifdef CONFIG_PM_SLEEP 251 252static int max17040_suspend(struct device *dev) 253{ 254 struct i2c_client *client = to_i2c_client(dev); 255 struct max17040_chip *chip = i2c_get_clientdata(client); 256 257 cancel_delayed_work(&chip->work); 258 return 0; 259} 260 261static int max17040_resume(struct device *dev) 262{ 263 struct i2c_client *client = to_i2c_client(dev); 264 struct max17040_chip *chip = i2c_get_clientdata(client); 265 266 schedule_delayed_work(&chip->work, MAX17040_DELAY); 267 return 0; 268} 269 270static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume); 271#define MAX17040_PM_OPS (&max17040_pm_ops) 272 273#else 274 275#define MAX17040_PM_OPS NULL 276 277#endif /* CONFIG_PM_SLEEP */ 278 279static const struct i2c_device_id max17040_id[] = { 280 { "max17040" }, 281 { "max77836-battery" }, 282 { } 283}; 284MODULE_DEVICE_TABLE(i2c, max17040_id); 285 286static struct i2c_driver max17040_i2c_driver = { 287 .driver = { 288 .name = "max17040", 289 .pm = MAX17040_PM_OPS, 290 }, 291 .probe = max17040_probe, 292 .remove = max17040_remove, 293 .id_table = max17040_id, 294}; 295module_i2c_driver(max17040_i2c_driver); 296 297MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); 298MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); 299MODULE_LICENSE("GPL"); 300