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/of_device.h>
19 #include <linux/max17040_battery.h>
20 #include <linux/regmap.h>
21 #include <linux/slab.h>
23 #define MAX17040_VCELL 0x02
24 #define MAX17040_SOC 0x04
25 #define MAX17040_MODE 0x06
26 #define MAX17040_VER 0x08
27 #define MAX17040_CONFIG 0x0C
28 #define MAX17040_STATUS 0x1A
29 #define MAX17040_CMD 0xFE
32 #define MAX17040_DELAY 1000
33 #define MAX17040_BATTERY_FULL 95
34 #define MAX17040_RCOMP_DEFAULT 0x9700
36 #define MAX17040_ATHD_MASK 0x3f
37 #define MAX17040_ALSC_MASK 0x40
38 #define MAX17040_ATHD_DEFAULT_POWER_UP 4
39 #define MAX17040_STATUS_HD_MASK 0x1000
40 #define MAX17040_STATUS_SC_MASK 0x2000
41 #define MAX17040_CFG_RCOMP_MASK 0xff00
54 /* values that differ by chip_id */
65 static struct chip_data max17040_family[] = {
71 .has_low_soc_alert = 0,
80 .has_low_soc_alert = 0,
89 .has_low_soc_alert = 1,
98 .has_low_soc_alert = 1,
107 .has_low_soc_alert = 1,
116 .has_low_soc_alert = 1,
125 .has_low_soc_alert = 1,
134 .has_low_soc_alert = 1,
140 struct max17040_chip {
141 struct i2c_client *client;
142 struct regmap *regmap;
143 struct delayed_work work;
144 struct power_supply *battery;
145 struct max17040_platform_data *pdata;
146 struct chip_data data;
148 /* battery capacity */
150 /* State Of Charge */
152 /* Low alert threshold from 32% to 1% of the State of Charge */
154 /* some devices return twice the capacity */
155 bool quirk_double_soc;
156 /* higher 8 bits for 17043+, 16 bits for 17040,41 */
160 static int max17040_reset(struct max17040_chip *chip)
162 return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val);
165 static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level)
167 level = 32 - level * (chip->quirk_double_soc ? 2 : 1);
168 return regmap_update_bits(chip->regmap, MAX17040_CONFIG,
169 MAX17040_ATHD_MASK, level);
172 static int max17040_set_soc_alert(struct max17040_chip *chip, bool enable)
174 return regmap_update_bits(chip->regmap, MAX17040_CONFIG,
175 MAX17040_ALSC_MASK, enable ? MAX17040_ALSC_MASK : 0);
178 static int max17040_set_rcomp(struct max17040_chip *chip, u16 rcomp)
180 u16 mask = chip->data.rcomp_bytes == 2 ?
181 0xffff : MAX17040_CFG_RCOMP_MASK;
183 return regmap_update_bits(chip->regmap, MAX17040_CONFIG, mask, rcomp);
186 static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell)
188 struct chip_data *d = &chip->data;
190 return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div;
194 static int max17040_get_vcell(struct max17040_chip *chip)
198 regmap_read(chip->regmap, MAX17040_VCELL, &vcell);
200 return max17040_raw_vcell_to_uvolts(chip, vcell);
203 static int max17040_get_soc(struct max17040_chip *chip)
207 regmap_read(chip->regmap, MAX17040_SOC, &soc);
209 return soc >> (chip->quirk_double_soc ? 9 : 8);
212 static int max17040_get_version(struct max17040_chip *chip)
217 ret = regmap_read(chip->regmap, MAX17040_VER, &version);
219 return ret ? ret : version;
222 static int max17040_get_online(struct max17040_chip *chip)
224 return chip->pdata && chip->pdata->battery_online ?
225 chip->pdata->battery_online() : 1;
228 static int max17040_get_status(struct max17040_chip *chip)
230 if (!chip->pdata || !chip->pdata->charger_online
231 || !chip->pdata->charger_enable)
232 return POWER_SUPPLY_STATUS_UNKNOWN;
234 if (max17040_get_soc(chip) > MAX17040_BATTERY_FULL)
235 return POWER_SUPPLY_STATUS_FULL;
237 if (chip->pdata->charger_online())
238 if (chip->pdata->charger_enable())
239 return POWER_SUPPLY_STATUS_CHARGING;
241 return POWER_SUPPLY_STATUS_NOT_CHARGING;
243 return POWER_SUPPLY_STATUS_DISCHARGING;
246 static int max17040_get_of_data(struct max17040_chip *chip)
248 struct device *dev = &chip->client->dev;
249 struct chip_data *data = &max17040_family[
250 (uintptr_t) of_device_get_match_data(dev)];
254 chip->quirk_double_soc = device_property_read_bool(dev,
257 chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
258 device_property_read_u32(dev,
259 "maxim,alert-low-soc-level",
260 &chip->low_soc_alert);
262 if (chip->low_soc_alert <= 0 ||
263 chip->low_soc_alert > (chip->quirk_double_soc ? 16 : 32)) {
264 dev_err(dev, "maxim,alert-low-soc-level out of bounds\n");
268 rcomp_len = device_property_count_u8(dev, "maxim,rcomp");
269 chip->rcomp = MAX17040_RCOMP_DEFAULT;
270 if (rcomp_len == data->rcomp_bytes) {
271 if (!device_property_read_u8_array(dev, "maxim,rcomp",
273 chip->rcomp = rcomp_len == 2 ? rcomp[0] << 8 | rcomp[1] :
275 } else if (rcomp_len > 0) {
276 dev_err(dev, "maxim,rcomp has incorrect length\n");
283 static void max17040_check_changes(struct max17040_chip *chip)
285 chip->soc = max17040_get_soc(chip);
286 chip->status = max17040_get_status(chip);
289 static void max17040_queue_work(struct max17040_chip *chip)
291 queue_delayed_work(system_power_efficient_wq, &chip->work,
295 static void max17040_stop_work(void *data)
297 struct max17040_chip *chip = data;
299 cancel_delayed_work_sync(&chip->work);
302 static void max17040_work(struct work_struct *work)
304 struct max17040_chip *chip;
305 int last_soc, last_status;
307 chip = container_of(work, struct max17040_chip, work.work);
309 /* store SOC and status to check changes */
310 last_soc = chip->soc;
311 last_status = chip->status;
312 max17040_check_changes(chip);
314 /* check changes and send uevent */
315 if (last_soc != chip->soc || last_status != chip->status)
316 power_supply_changed(chip->battery);
318 max17040_queue_work(chip);
321 /* Returns true if alert cause was SOC change, not low SOC */
322 static bool max17040_handle_soc_alert(struct max17040_chip *chip)
327 regmap_read(chip->regmap, MAX17040_STATUS, &data);
329 if (data & MAX17040_STATUS_HD_MASK) {
330 // this alert was caused by low soc
333 if (data & MAX17040_STATUS_SC_MASK) {
334 // soc change bit -- deassert to mark as handled
335 regmap_write(chip->regmap, MAX17040_STATUS,
336 data & ~MAX17040_STATUS_SC_MASK);
342 static irqreturn_t max17040_thread_handler(int id, void *dev)
344 struct max17040_chip *chip = dev;
346 if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip)))
347 dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n");
350 max17040_check_changes(chip);
353 power_supply_changed(chip->battery);
355 /* reset alert bit */
356 max17040_set_low_soc_alert(chip, chip->low_soc_alert);
361 static int max17040_enable_alert_irq(struct max17040_chip *chip)
363 struct i2c_client *client = chip->client;
367 flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
368 ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
369 max17040_thread_handler, flags,
370 chip->battery->desc->name, chip);
375 static int max17040_prop_writeable(struct power_supply *psy,
376 enum power_supply_property psp)
379 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
386 static int max17040_set_property(struct power_supply *psy,
387 enum power_supply_property psp,
388 const union power_supply_propval *val)
390 struct max17040_chip *chip = power_supply_get_drvdata(psy);
394 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
395 /* alert threshold can be programmed from 1% up to 16/32% */
396 if ((val->intval < 1) ||
397 (val->intval > (chip->quirk_double_soc ? 16 : 32))) {
401 ret = max17040_set_low_soc_alert(chip, val->intval);
402 chip->low_soc_alert = val->intval;
411 static int max17040_get_property(struct power_supply *psy,
412 enum power_supply_property psp,
413 union power_supply_propval *val)
415 struct max17040_chip *chip = power_supply_get_drvdata(psy);
418 case POWER_SUPPLY_PROP_STATUS:
419 val->intval = max17040_get_status(chip);
421 case POWER_SUPPLY_PROP_ONLINE:
422 val->intval = max17040_get_online(chip);
424 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
425 val->intval = max17040_get_vcell(chip);
427 case POWER_SUPPLY_PROP_CAPACITY:
428 val->intval = max17040_get_soc(chip);
430 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
431 val->intval = chip->low_soc_alert;
439 static const struct regmap_config max17040_regmap = {
443 .val_format_endian = REGMAP_ENDIAN_BIG,
446 static enum power_supply_property max17040_battery_props[] = {
447 POWER_SUPPLY_PROP_STATUS,
448 POWER_SUPPLY_PROP_ONLINE,
449 POWER_SUPPLY_PROP_VOLTAGE_NOW,
450 POWER_SUPPLY_PROP_CAPACITY,
451 POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,
454 static const struct power_supply_desc max17040_battery_desc = {
456 .type = POWER_SUPPLY_TYPE_BATTERY,
457 .get_property = max17040_get_property,
458 .set_property = max17040_set_property,
459 .property_is_writeable = max17040_prop_writeable,
460 .properties = max17040_battery_props,
461 .num_properties = ARRAY_SIZE(max17040_battery_props),
464 static int max17040_probe(struct i2c_client *client,
465 const struct i2c_device_id *id)
467 struct i2c_adapter *adapter = client->adapter;
468 struct power_supply_config psy_cfg = {};
469 struct max17040_chip *chip;
470 enum chip_id chip_id;
471 bool enable_irq = false;
474 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
477 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
481 chip->client = client;
482 chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap);
483 chip->pdata = client->dev.platform_data;
484 chip_id = (enum chip_id) id->driver_data;
485 if (client->dev.of_node) {
486 ret = max17040_get_of_data(chip);
489 chip_id = (uintptr_t)of_device_get_match_data(&client->dev);
491 chip->data = max17040_family[chip_id];
493 i2c_set_clientdata(client, chip);
494 psy_cfg.drv_data = chip;
496 chip->battery = devm_power_supply_register(&client->dev,
497 &max17040_battery_desc, &psy_cfg);
498 if (IS_ERR(chip->battery)) {
499 dev_err(&client->dev, "failed: power supply register\n");
500 return PTR_ERR(chip->battery);
503 ret = max17040_get_version(chip);
506 dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret);
508 if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041)
509 max17040_reset(chip);
511 max17040_set_rcomp(chip, chip->rcomp);
513 /* check interrupt */
514 if (client->irq && chip->data.has_low_soc_alert) {
515 ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert);
517 dev_err(&client->dev,
518 "Failed to set low SOC alert: err %d\n", ret);
525 if (client->irq && chip->data.has_soc_alert) {
526 ret = max17040_set_soc_alert(chip, 1);
528 dev_err(&client->dev,
529 "Failed to set SOC alert: err %d\n", ret);
534 /* soc alerts negate the need for polling */
535 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
536 ret = devm_add_action(&client->dev, max17040_stop_work, chip);
539 max17040_queue_work(chip);
543 ret = max17040_enable_alert_irq(chip);
546 dev_warn(&client->dev,
547 "Failed to get IRQ err %d\n", ret);
554 #ifdef CONFIG_PM_SLEEP
556 static int max17040_suspend(struct device *dev)
558 struct i2c_client *client = to_i2c_client(dev);
559 struct max17040_chip *chip = i2c_get_clientdata(client);
561 if (client->irq && chip->data.has_soc_alert)
562 // disable soc alert to prevent wakeup
563 max17040_set_soc_alert(chip, 0);
565 cancel_delayed_work(&chip->work);
567 if (client->irq && device_may_wakeup(dev))
568 enable_irq_wake(client->irq);
573 static int max17040_resume(struct device *dev)
575 struct i2c_client *client = to_i2c_client(dev);
576 struct max17040_chip *chip = i2c_get_clientdata(client);
578 if (client->irq && device_may_wakeup(dev))
579 disable_irq_wake(client->irq);
581 if (client->irq && chip->data.has_soc_alert)
582 max17040_set_soc_alert(chip, 1);
584 max17040_queue_work(chip);
589 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
590 #define MAX17040_PM_OPS (&max17040_pm_ops)
594 #define MAX17040_PM_OPS NULL
596 #endif /* CONFIG_PM_SLEEP */
598 static const struct i2c_device_id max17040_id[] = {
599 { "max17040", ID_MAX17040 },
600 { "max17041", ID_MAX17041 },
601 { "max17043", ID_MAX17043 },
602 { "max77836-battery", ID_MAX17043 },
603 { "max17044", ID_MAX17044 },
604 { "max17048", ID_MAX17048 },
605 { "max17049", ID_MAX17049 },
606 { "max17058", ID_MAX17058 },
607 { "max17059", ID_MAX17059 },
610 MODULE_DEVICE_TABLE(i2c, max17040_id);
612 static const struct of_device_id max17040_of_match[] = {
613 { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 },
614 { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 },
615 { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 },
616 { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 },
617 { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 },
618 { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 },
619 { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 },
620 { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 },
621 { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 },
624 MODULE_DEVICE_TABLE(of, max17040_of_match);
626 static struct i2c_driver max17040_i2c_driver = {
629 .of_match_table = max17040_of_match,
630 .pm = MAX17040_PM_OPS,
632 .probe = max17040_probe,
633 .id_table = max17040_id,
635 module_i2c_driver(max17040_i2c_driver);
637 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
638 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
639 MODULE_LICENSE("GPL");