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;
72 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
73 val->intval = chip->low_soc_alert;
81 static int max17040_write_reg(struct i2c_client *client, int reg, u16 value)
85 ret = i2c_smbus_write_word_swapped(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_word_swapped(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, 0x0054);
110 static int max17040_set_low_soc_alert(struct i2c_client *client, u32 level)
116 data = max17040_read_reg(client, MAX17040_RCOMP);
117 /* clear the alrt bit and set LSb 5 bits */
118 data &= MAX17040_ATHD_MASK;
120 ret = max17040_write_reg(client, MAX17040_RCOMP, data);
125 static void max17040_get_vcell(struct i2c_client *client)
127 struct max17040_chip *chip = i2c_get_clientdata(client);
130 vcell = max17040_read_reg(client, MAX17040_VCELL);
132 chip->vcell = (vcell >> 4) * 1250;
135 static void max17040_get_soc(struct i2c_client *client)
137 struct max17040_chip *chip = i2c_get_clientdata(client);
140 soc = max17040_read_reg(client, MAX17040_SOC);
142 chip->soc = (soc >> 8);
145 static void max17040_get_version(struct i2c_client *client)
149 version = max17040_read_reg(client, MAX17040_VER);
151 dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", version);
154 static void max17040_get_online(struct i2c_client *client)
156 struct max17040_chip *chip = i2c_get_clientdata(client);
158 if (chip->pdata && chip->pdata->battery_online)
159 chip->online = chip->pdata->battery_online();
164 static void max17040_get_status(struct i2c_client *client)
166 struct max17040_chip *chip = i2c_get_clientdata(client);
168 if (!chip->pdata || !chip->pdata->charger_online
169 || !chip->pdata->charger_enable) {
170 chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
174 if (chip->pdata->charger_online()) {
175 if (chip->pdata->charger_enable())
176 chip->status = POWER_SUPPLY_STATUS_CHARGING;
178 chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
180 chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
183 if (chip->soc > MAX17040_BATTERY_FULL)
184 chip->status = POWER_SUPPLY_STATUS_FULL;
187 static int max17040_get_of_data(struct max17040_chip *chip)
189 struct device *dev = &chip->client->dev;
191 chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
192 device_property_read_u32(dev,
193 "maxim,alert-low-soc-level",
194 &chip->low_soc_alert);
196 if (chip->low_soc_alert <= 0 || chip->low_soc_alert >= 33)
202 static void max17040_check_changes(struct i2c_client *client)
204 max17040_get_vcell(client);
205 max17040_get_soc(client);
206 max17040_get_online(client);
207 max17040_get_status(client);
210 static void max17040_work(struct work_struct *work)
212 struct max17040_chip *chip;
213 int last_soc, last_status;
215 chip = container_of(work, struct max17040_chip, work.work);
217 /* store SOC and status to check changes */
218 last_soc = chip->soc;
219 last_status = chip->status;
220 max17040_check_changes(chip->client);
222 /* check changes and send uevent */
223 if (last_soc != chip->soc || last_status != chip->status)
224 power_supply_changed(chip->battery);
226 queue_delayed_work(system_power_efficient_wq, &chip->work,
230 static irqreturn_t max17040_thread_handler(int id, void *dev)
232 struct max17040_chip *chip = dev;
233 struct i2c_client *client = chip->client;
235 dev_warn(&client->dev, "IRQ: Alert battery low level");
237 max17040_check_changes(chip->client);
240 power_supply_changed(chip->battery);
242 /* reset alert bit */
243 max17040_set_low_soc_alert(client, chip->low_soc_alert);
248 static int max17040_enable_alert_irq(struct max17040_chip *chip)
250 struct i2c_client *client = chip->client;
254 flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
255 ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
256 max17040_thread_handler, flags,
257 chip->battery->desc->name, chip);
262 static int max17040_prop_writeable(struct power_supply *psy,
263 enum power_supply_property psp)
266 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
273 static int max17040_set_property(struct power_supply *psy,
274 enum power_supply_property psp,
275 const union power_supply_propval *val)
277 struct max17040_chip *chip = power_supply_get_drvdata(psy);
281 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
282 /* alert threshold can be programmed from 1% up to 32% */
283 if ((val->intval < 1) || (val->intval > 32)) {
287 ret = max17040_set_low_soc_alert(chip->client, val->intval);
288 chip->low_soc_alert = val->intval;
297 static enum power_supply_property max17040_battery_props[] = {
298 POWER_SUPPLY_PROP_STATUS,
299 POWER_SUPPLY_PROP_ONLINE,
300 POWER_SUPPLY_PROP_VOLTAGE_NOW,
301 POWER_SUPPLY_PROP_CAPACITY,
302 POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,
305 static const struct power_supply_desc max17040_battery_desc = {
307 .type = POWER_SUPPLY_TYPE_BATTERY,
308 .get_property = max17040_get_property,
309 .set_property = max17040_set_property,
310 .property_is_writeable = max17040_prop_writeable,
311 .properties = max17040_battery_props,
312 .num_properties = ARRAY_SIZE(max17040_battery_props),
315 static int max17040_probe(struct i2c_client *client,
316 const struct i2c_device_id *id)
318 struct i2c_adapter *adapter = client->adapter;
319 struct power_supply_config psy_cfg = {};
320 struct max17040_chip *chip;
323 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
326 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
330 chip->client = client;
331 chip->pdata = client->dev.platform_data;
332 ret = max17040_get_of_data(chip);
334 dev_err(&client->dev,
335 "failed: low SOC alert OF data out of bounds\n");
339 i2c_set_clientdata(client, chip);
340 psy_cfg.drv_data = chip;
342 chip->battery = power_supply_register(&client->dev,
343 &max17040_battery_desc, &psy_cfg);
344 if (IS_ERR(chip->battery)) {
345 dev_err(&client->dev, "failed: power supply register\n");
346 return PTR_ERR(chip->battery);
349 max17040_reset(client);
350 max17040_get_version(client);
352 /* check interrupt */
353 if (client->irq && of_device_is_compatible(client->dev.of_node,
354 "maxim,max77836-battery")) {
355 ret = max17040_set_low_soc_alert(client, chip->low_soc_alert);
357 dev_err(&client->dev,
358 "Failed to set low SOC alert: err %d\n", ret);
362 ret = max17040_enable_alert_irq(chip);
365 dev_warn(&client->dev,
366 "Failed to get IRQ err %d\n", ret);
370 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
371 queue_delayed_work(system_power_efficient_wq, &chip->work,
377 static int max17040_remove(struct i2c_client *client)
379 struct max17040_chip *chip = i2c_get_clientdata(client);
381 power_supply_unregister(chip->battery);
382 cancel_delayed_work(&chip->work);
386 #ifdef CONFIG_PM_SLEEP
388 static int max17040_suspend(struct device *dev)
390 struct i2c_client *client = to_i2c_client(dev);
391 struct max17040_chip *chip = i2c_get_clientdata(client);
393 cancel_delayed_work(&chip->work);
395 if (client->irq && device_may_wakeup(dev))
396 enable_irq_wake(client->irq);
401 static int max17040_resume(struct device *dev)
403 struct i2c_client *client = to_i2c_client(dev);
404 struct max17040_chip *chip = i2c_get_clientdata(client);
406 queue_delayed_work(system_power_efficient_wq, &chip->work,
409 if (client->irq && device_may_wakeup(dev))
410 disable_irq_wake(client->irq);
415 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
416 #define MAX17040_PM_OPS (&max17040_pm_ops)
420 #define MAX17040_PM_OPS NULL
422 #endif /* CONFIG_PM_SLEEP */
424 static const struct i2c_device_id max17040_id[] = {
426 { "max77836-battery" },
429 MODULE_DEVICE_TABLE(i2c, max17040_id);
431 static const struct of_device_id max17040_of_match[] = {
432 { .compatible = "maxim,max17040" },
433 { .compatible = "maxim,max77836-battery" },
436 MODULE_DEVICE_TABLE(of, max17040_of_match);
438 static struct i2c_driver max17040_i2c_driver = {
441 .of_match_table = max17040_of_match,
442 .pm = MAX17040_PM_OPS,
444 .probe = max17040_probe,
445 .remove = max17040_remove,
446 .id_table = max17040_id,
448 module_i2c_driver(max17040_i2c_driver);
450 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
451 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
452 MODULE_LICENSE("GPL");