3 * fuel-gauge systems for lithium-ion (Li+) batteries
5 * Copyright (C) 2009 Samsung Electronics
6 * Minkyu Kang <mk7.kang@samsung.com>
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.
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>
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
37 #define MAX17040_DELAY 1000
38 #define MAX17040_BATTERY_FULL 95
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;
46 /* State Of Connect */
50 /* battery capacity */
56 static int max17040_get_property(struct power_supply *psy,
57 enum power_supply_property psp,
58 union power_supply_propval *val)
60 struct max17040_chip *chip = power_supply_get_drvdata(psy);
63 case POWER_SUPPLY_PROP_STATUS:
64 val->intval = chip->status;
66 case POWER_SUPPLY_PROP_ONLINE:
67 val->intval = chip->online;
69 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
70 val->intval = chip->vcell;
72 case POWER_SUPPLY_PROP_CAPACITY:
73 val->intval = chip->soc;
81 static int max17040_write_reg(struct i2c_client *client, int reg, u8 value)
85 ret = i2c_smbus_write_byte_data(client, reg, value);
88 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
93 static int max17040_read_reg(struct i2c_client *client, int reg)
97 ret = i2c_smbus_read_byte_data(client, reg);
100 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
105 static void max17040_reset(struct i2c_client *client)
107 max17040_write_reg(client, MAX17040_CMD_MSB, 0x54);
108 max17040_write_reg(client, MAX17040_CMD_LSB, 0x00);
111 static void max17040_get_vcell(struct i2c_client *client)
113 struct max17040_chip *chip = i2c_get_clientdata(client);
117 msb = max17040_read_reg(client, MAX17040_VCELL_MSB);
118 lsb = max17040_read_reg(client, MAX17040_VCELL_LSB);
120 chip->vcell = (msb << 4) + (lsb >> 4);
123 static void max17040_get_soc(struct i2c_client *client)
125 struct max17040_chip *chip = i2c_get_clientdata(client);
129 msb = max17040_read_reg(client, MAX17040_SOC_MSB);
130 lsb = max17040_read_reg(client, MAX17040_SOC_LSB);
135 static void max17040_get_version(struct i2c_client *client)
140 msb = max17040_read_reg(client, MAX17040_VER_MSB);
141 lsb = max17040_read_reg(client, MAX17040_VER_LSB);
143 dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver %d%d\n", msb, lsb);
146 static void max17040_get_online(struct i2c_client *client)
148 struct max17040_chip *chip = i2c_get_clientdata(client);
150 if (chip->pdata && chip->pdata->battery_online)
151 chip->online = chip->pdata->battery_online();
156 static void max17040_get_status(struct i2c_client *client)
158 struct max17040_chip *chip = i2c_get_clientdata(client);
160 if (!chip->pdata || !chip->pdata->charger_online
161 || !chip->pdata->charger_enable) {
162 chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
166 if (chip->pdata->charger_online()) {
167 if (chip->pdata->charger_enable())
168 chip->status = POWER_SUPPLY_STATUS_CHARGING;
170 chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
172 chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
175 if (chip->soc > MAX17040_BATTERY_FULL)
176 chip->status = POWER_SUPPLY_STATUS_FULL;
179 static void max17040_work(struct work_struct *work)
181 struct max17040_chip *chip;
183 chip = container_of(work, struct max17040_chip, work.work);
185 max17040_get_vcell(chip->client);
186 max17040_get_soc(chip->client);
187 max17040_get_online(chip->client);
188 max17040_get_status(chip->client);
190 queue_delayed_work(system_power_efficient_wq, &chip->work,
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,
201 static const struct power_supply_desc max17040_battery_desc = {
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),
209 static int max17040_probe(struct i2c_client *client,
210 const struct i2c_device_id *id)
212 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
213 struct power_supply_config psy_cfg = {};
214 struct max17040_chip *chip;
216 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
219 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
223 chip->client = client;
224 chip->pdata = client->dev.platform_data;
226 i2c_set_clientdata(client, chip);
227 psy_cfg.drv_data = chip;
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);
236 max17040_reset(client);
237 max17040_get_version(client);
239 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
240 queue_delayed_work(system_power_efficient_wq, &chip->work,
246 static int max17040_remove(struct i2c_client *client)
248 struct max17040_chip *chip = i2c_get_clientdata(client);
250 power_supply_unregister(chip->battery);
251 cancel_delayed_work(&chip->work);
255 #ifdef CONFIG_PM_SLEEP
257 static int max17040_suspend(struct device *dev)
259 struct i2c_client *client = to_i2c_client(dev);
260 struct max17040_chip *chip = i2c_get_clientdata(client);
262 cancel_delayed_work(&chip->work);
266 static int max17040_resume(struct device *dev)
268 struct i2c_client *client = to_i2c_client(dev);
269 struct max17040_chip *chip = i2c_get_clientdata(client);
271 queue_delayed_work(system_power_efficient_wq, &chip->work,
276 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
277 #define MAX17040_PM_OPS (&max17040_pm_ops)
281 #define MAX17040_PM_OPS NULL
283 #endif /* CONFIG_PM_SLEEP */
285 static const struct i2c_device_id max17040_id[] = {
287 { "max77836-battery" },
290 MODULE_DEVICE_TABLE(i2c, max17040_id);
292 static struct i2c_driver max17040_i2c_driver = {
295 .pm = MAX17040_PM_OPS,
297 .probe = max17040_probe,
298 .remove = max17040_remove,
299 .id_table = max17040_id,
301 module_i2c_driver(max17040_i2c_driver);
303 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
304 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
305 MODULE_LICENSE("GPL");