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 device_property_read_u8_array(dev, "maxim,rcomp",
273 chip->rcomp = rcomp_len == 2 ?
274 rcomp[0] << 8 | rcomp[1] :
276 } else if (rcomp_len > 0) {
277 dev_err(dev, "maxim,rcomp has incorrect length\n");
284 static void max17040_check_changes(struct max17040_chip *chip)
286 chip->soc = max17040_get_soc(chip);
287 chip->status = max17040_get_status(chip);
290 static void max17040_queue_work(struct max17040_chip *chip)
292 queue_delayed_work(system_power_efficient_wq, &chip->work,
296 static void max17040_stop_work(void *data)
298 struct max17040_chip *chip = data;
300 cancel_delayed_work_sync(&chip->work);
303 static void max17040_work(struct work_struct *work)
305 struct max17040_chip *chip;
306 int last_soc, last_status;
308 chip = container_of(work, struct max17040_chip, work.work);
310 /* store SOC and status to check changes */
311 last_soc = chip->soc;
312 last_status = chip->status;
313 max17040_check_changes(chip);
315 /* check changes and send uevent */
316 if (last_soc != chip->soc || last_status != chip->status)
317 power_supply_changed(chip->battery);
319 max17040_queue_work(chip);
322 /* Returns true if alert cause was SOC change, not low SOC */
323 static bool max17040_handle_soc_alert(struct max17040_chip *chip)
328 regmap_read(chip->regmap, MAX17040_STATUS, &data);
330 if (data & MAX17040_STATUS_HD_MASK) {
331 // this alert was caused by low soc
334 if (data & MAX17040_STATUS_SC_MASK) {
335 // soc change bit -- deassert to mark as handled
336 regmap_write(chip->regmap, MAX17040_STATUS,
337 data & ~MAX17040_STATUS_SC_MASK);
343 static irqreturn_t max17040_thread_handler(int id, void *dev)
345 struct max17040_chip *chip = dev;
347 if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip)))
348 dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n");
351 max17040_check_changes(chip);
354 power_supply_changed(chip->battery);
356 /* reset alert bit */
357 max17040_set_low_soc_alert(chip, chip->low_soc_alert);
362 static int max17040_enable_alert_irq(struct max17040_chip *chip)
364 struct i2c_client *client = chip->client;
368 flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
369 ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
370 max17040_thread_handler, flags,
371 chip->battery->desc->name, chip);
376 static int max17040_prop_writeable(struct power_supply *psy,
377 enum power_supply_property psp)
380 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
387 static int max17040_set_property(struct power_supply *psy,
388 enum power_supply_property psp,
389 const union power_supply_propval *val)
391 struct max17040_chip *chip = power_supply_get_drvdata(psy);
395 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
396 /* alert threshold can be programmed from 1% up to 16/32% */
397 if ((val->intval < 1) ||
398 (val->intval > (chip->quirk_double_soc ? 16 : 32))) {
402 ret = max17040_set_low_soc_alert(chip, val->intval);
403 chip->low_soc_alert = val->intval;
412 static int max17040_get_property(struct power_supply *psy,
413 enum power_supply_property psp,
414 union power_supply_propval *val)
416 struct max17040_chip *chip = power_supply_get_drvdata(psy);
419 case POWER_SUPPLY_PROP_STATUS:
420 val->intval = max17040_get_status(chip);
422 case POWER_SUPPLY_PROP_ONLINE:
423 val->intval = max17040_get_online(chip);
425 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
426 val->intval = max17040_get_vcell(chip);
428 case POWER_SUPPLY_PROP_CAPACITY:
429 val->intval = max17040_get_soc(chip);
431 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:
432 val->intval = chip->low_soc_alert;
440 static const struct regmap_config max17040_regmap = {
444 .val_format_endian = REGMAP_ENDIAN_BIG,
447 static enum power_supply_property max17040_battery_props[] = {
448 POWER_SUPPLY_PROP_STATUS,
449 POWER_SUPPLY_PROP_ONLINE,
450 POWER_SUPPLY_PROP_VOLTAGE_NOW,
451 POWER_SUPPLY_PROP_CAPACITY,
452 POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,
455 static const struct power_supply_desc max17040_battery_desc = {
457 .type = POWER_SUPPLY_TYPE_BATTERY,
458 .get_property = max17040_get_property,
459 .set_property = max17040_set_property,
460 .property_is_writeable = max17040_prop_writeable,
461 .properties = max17040_battery_props,
462 .num_properties = ARRAY_SIZE(max17040_battery_props),
465 static int max17040_probe(struct i2c_client *client,
466 const struct i2c_device_id *id)
468 struct i2c_adapter *adapter = client->adapter;
469 struct power_supply_config psy_cfg = {};
470 struct max17040_chip *chip;
471 enum chip_id chip_id;
472 bool enable_irq = false;
475 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
478 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
482 chip->client = client;
483 chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap);
484 chip->pdata = client->dev.platform_data;
485 if (IS_ERR(chip->regmap))
486 return PTR_ERR(chip->regmap);
487 chip_id = (enum chip_id) id->driver_data;
488 if (client->dev.of_node) {
489 ret = max17040_get_of_data(chip);
492 chip_id = (enum chip_id) (uintptr_t)
493 of_device_get_match_data(&client->dev);
495 chip->data = max17040_family[chip_id];
497 i2c_set_clientdata(client, chip);
498 psy_cfg.drv_data = chip;
500 chip->battery = devm_power_supply_register(&client->dev,
501 &max17040_battery_desc, &psy_cfg);
502 if (IS_ERR(chip->battery)) {
503 dev_err(&client->dev, "failed: power supply register\n");
504 return PTR_ERR(chip->battery);
507 ret = max17040_get_version(chip);
510 dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret);
512 if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041)
513 max17040_reset(chip);
515 max17040_set_rcomp(chip, chip->rcomp);
517 /* check interrupt */
518 if (client->irq && chip->data.has_low_soc_alert) {
519 ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert);
521 dev_err(&client->dev,
522 "Failed to set low SOC alert: err %d\n", ret);
529 if (client->irq && chip->data.has_soc_alert) {
530 ret = max17040_set_soc_alert(chip, 1);
532 dev_err(&client->dev,
533 "Failed to set SOC alert: err %d\n", ret);
538 /* soc alerts negate the need for polling */
539 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
540 ret = devm_add_action(&client->dev, max17040_stop_work, chip);
543 max17040_queue_work(chip);
547 ret = max17040_enable_alert_irq(chip);
550 dev_warn(&client->dev,
551 "Failed to get IRQ err %d\n", ret);
558 #ifdef CONFIG_PM_SLEEP
560 static int max17040_suspend(struct device *dev)
562 struct i2c_client *client = to_i2c_client(dev);
563 struct max17040_chip *chip = i2c_get_clientdata(client);
565 if (client->irq && chip->data.has_soc_alert)
566 // disable soc alert to prevent wakeup
567 max17040_set_soc_alert(chip, 0);
569 cancel_delayed_work(&chip->work);
571 if (client->irq && device_may_wakeup(dev))
572 enable_irq_wake(client->irq);
577 static int max17040_resume(struct device *dev)
579 struct i2c_client *client = to_i2c_client(dev);
580 struct max17040_chip *chip = i2c_get_clientdata(client);
582 if (client->irq && device_may_wakeup(dev))
583 disable_irq_wake(client->irq);
585 if (client->irq && chip->data.has_soc_alert)
586 max17040_set_soc_alert(chip, 1);
588 max17040_queue_work(chip);
593 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
594 #define MAX17040_PM_OPS (&max17040_pm_ops)
598 #define MAX17040_PM_OPS NULL
600 #endif /* CONFIG_PM_SLEEP */
602 static const struct i2c_device_id max17040_id[] = {
603 { "max17040", ID_MAX17040 },
604 { "max17041", ID_MAX17041 },
605 { "max17043", ID_MAX17043 },
606 { "max77836-battery", ID_MAX17043 },
607 { "max17044", ID_MAX17044 },
608 { "max17048", ID_MAX17048 },
609 { "max17049", ID_MAX17049 },
610 { "max17058", ID_MAX17058 },
611 { "max17059", ID_MAX17059 },
614 MODULE_DEVICE_TABLE(i2c, max17040_id);
616 static const struct of_device_id max17040_of_match[] = {
617 { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 },
618 { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 },
619 { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 },
620 { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 },
621 { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 },
622 { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 },
623 { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 },
624 { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 },
625 { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 },
628 MODULE_DEVICE_TABLE(of, max17040_of_match);
630 static struct i2c_driver max17040_i2c_driver = {
633 .of_match_table = max17040_of_match,
634 .pm = MAX17040_PM_OPS,
636 .probe = max17040_probe,
637 .id_table = max17040_id,
639 module_i2c_driver(max17040_i2c_driver);
641 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
642 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
643 MODULE_LICENSE("GPL");