1 // SPDX-License-Identifier: GPL-2.0
4 // fuel-gauge systems for lithium-ion (Li+) batteries
6 // Copyright (C) 2009 Samsung Electronics
7 // Minkyu Kang <mk7.kang@samsung.com>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/platform_device.h>
12 #include <linux/mutex.h>
13 #include <linux/err.h>
14 #include <linux/i2c.h>
15 #include <linux/delay.h>
16 #include <linux/interrupt.h>
17 #include <linux/power_supply.h>
18 #include <linux/max17040_battery.h>
19 #include <linux/slab.h>
21 #define MAX17040_VCELL 0x02
22 #define MAX17040_SOC 0x04
23 #define MAX17040_MODE 0x06
24 #define MAX17040_VER 0x08
25 #define MAX17040_RCOMP 0x0C
26 #define MAX17040_CMD 0xFE
29 #define MAX17040_DELAY 1000
30 #define MAX17040_BATTERY_FULL 95
32 #define MAX17040_ATHD_MASK 0xFFC0
33 #define MAX17040_ATHD_DEFAULT_POWER_UP 4
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;
41 /* State Of Connect */
45 /* battery capacity */
49 /* Low alert threshold from 32% to 1% of the State of Charge */
53 static int max17040_get_property(struct power_supply *psy,
54 enum power_supply_property psp,
55 union power_supply_propval *val)
57 struct max17040_chip *chip = power_supply_get_drvdata(psy);
60 case POWER_SUPPLY_PROP_STATUS:
61 val->intval = chip->status;
63 case POWER_SUPPLY_PROP_ONLINE:
64 val->intval = chip->online;
66 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
67 val->intval = chip->vcell;
69 case POWER_SUPPLY_PROP_CAPACITY:
70 val->intval = chip->soc;
78 static int max17040_write_reg(struct i2c_client *client, int reg, u16 value)
82 ret = i2c_smbus_write_word_swapped(client, reg, value);
85 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
90 static int max17040_read_reg(struct i2c_client *client, int reg)
94 ret = i2c_smbus_read_word_swapped(client, reg);
97 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
102 static void max17040_reset(struct i2c_client *client)
104 max17040_write_reg(client, MAX17040_CMD, 0x0054);
107 static int max17040_set_low_soc_alert(struct i2c_client *client, u32 level)
113 data = max17040_read_reg(client, MAX17040_RCOMP);
114 /* clear the alrt bit and set LSb 5 bits */
115 data &= MAX17040_ATHD_MASK;
117 ret = max17040_write_reg(client, MAX17040_RCOMP, data);
122 static void max17040_get_vcell(struct i2c_client *client)
124 struct max17040_chip *chip = i2c_get_clientdata(client);
127 vcell = max17040_read_reg(client, MAX17040_VCELL);
132 static void max17040_get_soc(struct i2c_client *client)
134 struct max17040_chip *chip = i2c_get_clientdata(client);
137 soc = max17040_read_reg(client, MAX17040_SOC);
139 chip->soc = (soc >> 8);
142 static void max17040_get_version(struct i2c_client *client)
146 version = max17040_read_reg(client, MAX17040_VER);
148 dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", version);
151 static void max17040_get_online(struct i2c_client *client)
153 struct max17040_chip *chip = i2c_get_clientdata(client);
155 if (chip->pdata && chip->pdata->battery_online)
156 chip->online = chip->pdata->battery_online();
161 static void max17040_get_status(struct i2c_client *client)
163 struct max17040_chip *chip = i2c_get_clientdata(client);
165 if (!chip->pdata || !chip->pdata->charger_online
166 || !chip->pdata->charger_enable) {
167 chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
171 if (chip->pdata->charger_online()) {
172 if (chip->pdata->charger_enable())
173 chip->status = POWER_SUPPLY_STATUS_CHARGING;
175 chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
177 chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
180 if (chip->soc > MAX17040_BATTERY_FULL)
181 chip->status = POWER_SUPPLY_STATUS_FULL;
184 static int max17040_get_of_data(struct max17040_chip *chip)
186 struct device *dev = &chip->client->dev;
188 chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
189 device_property_read_u32(dev,
190 "maxim,alert-low-soc-level",
191 &chip->low_soc_alert);
193 if (chip->low_soc_alert <= 0 || chip->low_soc_alert >= 33)
199 static void max17040_check_changes(struct i2c_client *client)
201 max17040_get_vcell(client);
202 max17040_get_soc(client);
203 max17040_get_online(client);
204 max17040_get_status(client);
207 static void max17040_work(struct work_struct *work)
209 struct max17040_chip *chip;
210 int last_soc, last_status;
212 chip = container_of(work, struct max17040_chip, work.work);
214 /* store SOC and status to check changes */
215 last_soc = chip->soc;
216 last_status = chip->status;
217 max17040_check_changes(chip->client);
219 /* check changes and send uevent */
220 if (last_soc != chip->soc || last_status != chip->status)
221 power_supply_changed(chip->battery);
223 queue_delayed_work(system_power_efficient_wq, &chip->work,
227 static irqreturn_t max17040_thread_handler(int id, void *dev)
229 struct max17040_chip *chip = dev;
230 struct i2c_client *client = chip->client;
232 dev_warn(&client->dev, "IRQ: Alert battery low level");
234 max17040_check_changes(chip->client);
237 power_supply_changed(chip->battery);
239 /* reset alert bit */
240 max17040_set_low_soc_alert(client, chip->low_soc_alert);
245 static int max17040_enable_alert_irq(struct max17040_chip *chip)
247 struct i2c_client *client = chip->client;
251 flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
252 ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
253 max17040_thread_handler, flags,
254 chip->battery->desc->name, chip);
259 static enum power_supply_property max17040_battery_props[] = {
260 POWER_SUPPLY_PROP_STATUS,
261 POWER_SUPPLY_PROP_ONLINE,
262 POWER_SUPPLY_PROP_VOLTAGE_NOW,
263 POWER_SUPPLY_PROP_CAPACITY,
266 static const struct power_supply_desc max17040_battery_desc = {
268 .type = POWER_SUPPLY_TYPE_BATTERY,
269 .get_property = max17040_get_property,
270 .properties = max17040_battery_props,
271 .num_properties = ARRAY_SIZE(max17040_battery_props),
274 static int max17040_probe(struct i2c_client *client,
275 const struct i2c_device_id *id)
277 struct i2c_adapter *adapter = client->adapter;
278 struct power_supply_config psy_cfg = {};
279 struct max17040_chip *chip;
282 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
285 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
289 chip->client = client;
290 chip->pdata = client->dev.platform_data;
291 ret = max17040_get_of_data(chip);
293 dev_err(&client->dev,
294 "failed: low SOC alert OF data out of bounds\n");
298 i2c_set_clientdata(client, chip);
299 psy_cfg.drv_data = chip;
301 chip->battery = power_supply_register(&client->dev,
302 &max17040_battery_desc, &psy_cfg);
303 if (IS_ERR(chip->battery)) {
304 dev_err(&client->dev, "failed: power supply register\n");
305 return PTR_ERR(chip->battery);
308 max17040_reset(client);
309 max17040_get_version(client);
311 /* check interrupt */
312 if (client->irq && of_device_is_compatible(client->dev.of_node,
313 "maxim,max77836-battery")) {
314 ret = max17040_set_low_soc_alert(client, chip->low_soc_alert);
316 dev_err(&client->dev,
317 "Failed to set low SOC alert: err %d\n", ret);
321 ret = max17040_enable_alert_irq(chip);
324 dev_warn(&client->dev,
325 "Failed to get IRQ err %d\n", ret);
329 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
330 queue_delayed_work(system_power_efficient_wq, &chip->work,
336 static int max17040_remove(struct i2c_client *client)
338 struct max17040_chip *chip = i2c_get_clientdata(client);
340 power_supply_unregister(chip->battery);
341 cancel_delayed_work(&chip->work);
345 #ifdef CONFIG_PM_SLEEP
347 static int max17040_suspend(struct device *dev)
349 struct i2c_client *client = to_i2c_client(dev);
350 struct max17040_chip *chip = i2c_get_clientdata(client);
352 cancel_delayed_work(&chip->work);
354 if (client->irq && device_may_wakeup(dev))
355 enable_irq_wake(client->irq);
360 static int max17040_resume(struct device *dev)
362 struct i2c_client *client = to_i2c_client(dev);
363 struct max17040_chip *chip = i2c_get_clientdata(client);
365 queue_delayed_work(system_power_efficient_wq, &chip->work,
368 if (client->irq && device_may_wakeup(dev))
369 disable_irq_wake(client->irq);
374 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
375 #define MAX17040_PM_OPS (&max17040_pm_ops)
379 #define MAX17040_PM_OPS NULL
381 #endif /* CONFIG_PM_SLEEP */
383 static const struct i2c_device_id max17040_id[] = {
385 { "max77836-battery" },
388 MODULE_DEVICE_TABLE(i2c, max17040_id);
390 static const struct of_device_id max17040_of_match[] = {
391 { .compatible = "maxim,max17040" },
392 { .compatible = "maxim,max77836-battery" },
395 MODULE_DEVICE_TABLE(of, max17040_of_match);
397 static struct i2c_driver max17040_i2c_driver = {
400 .of_match_table = max17040_of_match,
401 .pm = MAX17040_PM_OPS,
403 .probe = max17040_probe,
404 .remove = max17040_remove,
405 .id_table = max17040_id,
407 module_i2c_driver(max17040_i2c_driver);
409 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
410 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
411 MODULE_LICENSE("GPL");