637 lines · c
1// SPDX-License-Identifier: GPL-2.02//3// max17040_battery.c4// fuel-gauge systems for lithium-ion (Li+) batteries5//6// Copyright (C) 2009 Samsung Electronics7// Minkyu Kang <mk7.kang@samsung.com>8 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.h>19#include <linux/regmap.h>20#include <linux/slab.h>21#include <linux/iio/consumer.h>22 23#define MAX17040_VCELL 0x0224#define MAX17040_SOC 0x0425#define MAX17040_MODE 0x0626#define MAX17040_VER 0x0827#define MAX17040_CONFIG 0x0C28#define MAX17040_STATUS 0x1A29#define MAX17040_CMD 0xFE30 31 32#define MAX17040_DELAY 100033#define MAX17040_BATTERY_FULL 9534#define MAX17040_RCOMP_DEFAULT 0x970035 36#define MAX17040_ATHD_MASK 0x3f37#define MAX17040_ALSC_MASK 0x4038#define MAX17040_ATHD_DEFAULT_POWER_UP 439#define MAX17040_STATUS_HD_MASK 0x100040#define MAX17040_STATUS_SC_MASK 0x200041#define MAX17040_CFG_RCOMP_MASK 0xff0042 43enum chip_id {44 ID_MAX17040,45 ID_MAX17041,46 ID_MAX17043,47 ID_MAX17044,48 ID_MAX17048,49 ID_MAX17049,50 ID_MAX17058,51 ID_MAX17059,52};53 54/* values that differ by chip_id */55struct chip_data {56 u16 reset_val;57 u16 vcell_shift;58 u16 vcell_mul;59 u16 vcell_div;60 u8 has_low_soc_alert;61 u8 rcomp_bytes;62 u8 has_soc_alert;63};64 65static struct chip_data max17040_family[] = {66 [ID_MAX17040] = {67 .reset_val = 0x0054,68 .vcell_shift = 4,69 .vcell_mul = 1250,70 .vcell_div = 1,71 .has_low_soc_alert = 0,72 .rcomp_bytes = 2,73 .has_soc_alert = 0,74 },75 [ID_MAX17041] = {76 .reset_val = 0x0054,77 .vcell_shift = 4,78 .vcell_mul = 2500,79 .vcell_div = 1,80 .has_low_soc_alert = 0,81 .rcomp_bytes = 2,82 .has_soc_alert = 0,83 },84 [ID_MAX17043] = {85 .reset_val = 0x0054,86 .vcell_shift = 4,87 .vcell_mul = 1250,88 .vcell_div = 1,89 .has_low_soc_alert = 1,90 .rcomp_bytes = 1,91 .has_soc_alert = 0,92 },93 [ID_MAX17044] = {94 .reset_val = 0x0054,95 .vcell_shift = 4,96 .vcell_mul = 2500,97 .vcell_div = 1,98 .has_low_soc_alert = 1,99 .rcomp_bytes = 1,100 .has_soc_alert = 0,101 },102 [ID_MAX17048] = {103 .reset_val = 0x5400,104 .vcell_shift = 0,105 .vcell_mul = 625,106 .vcell_div = 8,107 .has_low_soc_alert = 1,108 .rcomp_bytes = 1,109 .has_soc_alert = 1,110 },111 [ID_MAX17049] = {112 .reset_val = 0x5400,113 .vcell_shift = 0,114 .vcell_mul = 625,115 .vcell_div = 4,116 .has_low_soc_alert = 1,117 .rcomp_bytes = 1,118 .has_soc_alert = 1,119 },120 [ID_MAX17058] = {121 .reset_val = 0x5400,122 .vcell_shift = 0,123 .vcell_mul = 625,124 .vcell_div = 8,125 .has_low_soc_alert = 1,126 .rcomp_bytes = 1,127 .has_soc_alert = 0,128 },129 [ID_MAX17059] = {130 .reset_val = 0x5400,131 .vcell_shift = 0,132 .vcell_mul = 625,133 .vcell_div = 4,134 .has_low_soc_alert = 1,135 .rcomp_bytes = 1,136 .has_soc_alert = 0,137 },138};139 140struct max17040_chip {141 struct i2c_client *client;142 struct regmap *regmap;143 struct delayed_work work;144 struct power_supply *battery;145 struct chip_data data;146 struct iio_channel *channel_temp;147 148 /* battery capacity */149 int soc;150 /* Low alert threshold from 32% to 1% of the State of Charge */151 u32 low_soc_alert;152 /* some devices return twice the capacity */153 bool quirk_double_soc;154 /* higher 8 bits for 17043+, 16 bits for 17040,41 */155 u16 rcomp;156};157 158static int max17040_reset(struct max17040_chip *chip)159{160 return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val);161}162 163static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level)164{165 level = 32 - level * (chip->quirk_double_soc ? 2 : 1);166 return regmap_update_bits(chip->regmap, MAX17040_CONFIG,167 MAX17040_ATHD_MASK, level);168}169 170static int max17040_set_soc_alert(struct max17040_chip *chip, bool enable)171{172 return regmap_update_bits(chip->regmap, MAX17040_CONFIG,173 MAX17040_ALSC_MASK, enable ? MAX17040_ALSC_MASK : 0);174}175 176static int max17040_set_rcomp(struct max17040_chip *chip, u16 rcomp)177{178 u16 mask = chip->data.rcomp_bytes == 2 ?179 0xffff : MAX17040_CFG_RCOMP_MASK;180 181 return regmap_update_bits(chip->regmap, MAX17040_CONFIG, mask, rcomp);182}183 184static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell)185{186 struct chip_data *d = &chip->data;187 188 return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div;189}190 191 192static int max17040_get_vcell(struct max17040_chip *chip)193{194 u32 vcell;195 196 regmap_read(chip->regmap, MAX17040_VCELL, &vcell);197 198 return max17040_raw_vcell_to_uvolts(chip, vcell);199}200 201static int max17040_get_soc(struct max17040_chip *chip)202{203 u32 soc;204 205 regmap_read(chip->regmap, MAX17040_SOC, &soc);206 207 return soc >> (chip->quirk_double_soc ? 9 : 8);208}209 210static int max17040_get_version(struct max17040_chip *chip)211{212 int ret;213 u32 version;214 215 ret = regmap_read(chip->regmap, MAX17040_VER, &version);216 217 return ret ? ret : version;218}219 220static int max17040_get_online(struct max17040_chip *chip)221{222 return 1;223}224 225static int max17040_get_of_data(struct max17040_chip *chip)226{227 struct device *dev = &chip->client->dev;228 struct chip_data *data = &max17040_family[229 (uintptr_t) of_device_get_match_data(dev)];230 int rcomp_len;231 u8 rcomp[2];232 233 chip->quirk_double_soc = device_property_read_bool(dev,234 "maxim,double-soc");235 236 chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;237 device_property_read_u32(dev,238 "maxim,alert-low-soc-level",239 &chip->low_soc_alert);240 241 if (chip->low_soc_alert <= 0 ||242 chip->low_soc_alert > (chip->quirk_double_soc ? 16 : 32)) {243 dev_err(dev, "maxim,alert-low-soc-level out of bounds\n");244 return -EINVAL;245 }246 247 rcomp_len = device_property_count_u8(dev, "maxim,rcomp");248 chip->rcomp = MAX17040_RCOMP_DEFAULT;249 if (rcomp_len == data->rcomp_bytes) {250 if (!device_property_read_u8_array(dev, "maxim,rcomp",251 rcomp, rcomp_len))252 chip->rcomp = rcomp_len == 2 ? rcomp[0] << 8 | rcomp[1] :253 rcomp[0] << 8;254 } else if (rcomp_len > 0) {255 dev_err(dev, "maxim,rcomp has incorrect length\n");256 return -EINVAL;257 }258 259 return 0;260}261 262static void max17040_check_changes(struct max17040_chip *chip)263{264 chip->soc = max17040_get_soc(chip);265}266 267static void max17040_queue_work(struct max17040_chip *chip)268{269 queue_delayed_work(system_power_efficient_wq, &chip->work,270 MAX17040_DELAY);271}272 273static void max17040_stop_work(void *data)274{275 struct max17040_chip *chip = data;276 277 cancel_delayed_work_sync(&chip->work);278}279 280static void max17040_work(struct work_struct *work)281{282 struct max17040_chip *chip;283 int last_soc;284 285 chip = container_of(work, struct max17040_chip, work.work);286 287 /* store SOC to check changes */288 last_soc = chip->soc;289 max17040_check_changes(chip);290 291 /* check changes and send uevent */292 if (last_soc != chip->soc)293 power_supply_changed(chip->battery);294 295 max17040_queue_work(chip);296}297 298/* Returns true if alert cause was SOC change, not low SOC */299static bool max17040_handle_soc_alert(struct max17040_chip *chip)300{301 bool ret = true;302 u32 data;303 304 regmap_read(chip->regmap, MAX17040_STATUS, &data);305 306 if (data & MAX17040_STATUS_HD_MASK) {307 // this alert was caused by low soc308 ret = false;309 }310 if (data & MAX17040_STATUS_SC_MASK) {311 // soc change bit -- deassert to mark as handled312 regmap_write(chip->regmap, MAX17040_STATUS,313 data & ~MAX17040_STATUS_SC_MASK);314 }315 316 return ret;317}318 319static irqreturn_t max17040_thread_handler(int id, void *dev)320{321 struct max17040_chip *chip = dev;322 323 if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip)))324 dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n");325 326 /* read registers */327 max17040_check_changes(chip);328 329 /* send uevent */330 power_supply_changed(chip->battery);331 332 /* reset alert bit */333 max17040_set_low_soc_alert(chip, chip->low_soc_alert);334 335 return IRQ_HANDLED;336}337 338static int max17040_enable_alert_irq(struct max17040_chip *chip)339{340 struct i2c_client *client = chip->client;341 int ret;342 343 ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,344 max17040_thread_handler, IRQF_ONESHOT,345 chip->battery->desc->name, chip);346 347 return ret;348}349 350static int max17040_prop_writeable(struct power_supply *psy,351 enum power_supply_property psp)352{353 switch (psp) {354 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:355 return 1;356 default:357 return 0;358 }359}360 361static int max17040_set_property(struct power_supply *psy,362 enum power_supply_property psp,363 const union power_supply_propval *val)364{365 struct max17040_chip *chip = power_supply_get_drvdata(psy);366 int ret;367 368 switch (psp) {369 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:370 /* alert threshold can be programmed from 1% up to 16/32% */371 if ((val->intval < 1) ||372 (val->intval > (chip->quirk_double_soc ? 16 : 32))) {373 ret = -EINVAL;374 break;375 }376 ret = max17040_set_low_soc_alert(chip, val->intval);377 chip->low_soc_alert = val->intval;378 break;379 default:380 ret = -EINVAL;381 }382 383 return ret;384}385 386static int max17040_get_property(struct power_supply *psy,387 enum power_supply_property psp,388 union power_supply_propval *val)389{390 struct max17040_chip *chip = power_supply_get_drvdata(psy);391 392 switch (psp) {393 case POWER_SUPPLY_PROP_ONLINE:394 case POWER_SUPPLY_PROP_PRESENT:395 val->intval = max17040_get_online(chip);396 break;397 case POWER_SUPPLY_PROP_VOLTAGE_NOW:398 val->intval = max17040_get_vcell(chip);399 break;400 case POWER_SUPPLY_PROP_CAPACITY:401 val->intval = max17040_get_soc(chip);402 break;403 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN:404 val->intval = chip->low_soc_alert;405 break;406 case POWER_SUPPLY_PROP_STATUS:407 power_supply_get_property_from_supplier(psy, psp, val);408 break;409 case POWER_SUPPLY_PROP_TEMP:410 if (!chip->channel_temp)411 return -ENODATA;412 413 iio_read_channel_processed_scale(chip->channel_temp,414 &val->intval, 10);415 break;416 default:417 return -EINVAL;418 }419 return 0;420}421 422static const struct regmap_config max17040_regmap = {423 .reg_bits = 8,424 .reg_stride = 2,425 .val_bits = 16,426 .val_format_endian = REGMAP_ENDIAN_BIG,427};428 429static enum power_supply_property max17040_battery_props[] = {430 POWER_SUPPLY_PROP_ONLINE,431 POWER_SUPPLY_PROP_PRESENT,432 POWER_SUPPLY_PROP_VOLTAGE_NOW,433 POWER_SUPPLY_PROP_CAPACITY,434 POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN,435 POWER_SUPPLY_PROP_STATUS,436 POWER_SUPPLY_PROP_TEMP,437};438 439static const struct power_supply_desc max17040_battery_desc = {440 .name = "battery",441 .type = POWER_SUPPLY_TYPE_BATTERY,442 .get_property = max17040_get_property,443 .set_property = max17040_set_property,444 .property_is_writeable = max17040_prop_writeable,445 .properties = max17040_battery_props,446 .num_properties = ARRAY_SIZE(max17040_battery_props),447};448 449static int max17040_probe(struct i2c_client *client)450{451 const struct i2c_device_id *id = i2c_client_get_device_id(client);452 struct i2c_adapter *adapter = client->adapter;453 struct power_supply_config psy_cfg = {};454 struct max17040_chip *chip;455 enum chip_id chip_id;456 bool enable_irq = false;457 int ret;458 459 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))460 return -EIO;461 462 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);463 if (!chip)464 return -ENOMEM;465 466 chip->client = client;467 chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap);468 if (IS_ERR(chip->regmap))469 return PTR_ERR(chip->regmap);470 chip_id = (enum chip_id) id->driver_data;471 if (client->dev.of_node) {472 ret = max17040_get_of_data(chip);473 if (ret)474 return ret;475 chip_id = (uintptr_t)of_device_get_match_data(&client->dev);476 }477 chip->data = max17040_family[chip_id];478 479 i2c_set_clientdata(client, chip);480 psy_cfg.drv_data = chip;481 482 /* Switch to devm_iio_channel_get_optional when available */483 chip->channel_temp = devm_iio_channel_get(&client->dev, "temp");484 if (IS_ERR(chip->channel_temp)) {485 ret = PTR_ERR(chip->channel_temp);486 if (ret != -ENODEV)487 return dev_err_probe(&client->dev, PTR_ERR(chip->channel_temp),488 "failed to get temp\n");489 else490 chip->channel_temp = NULL;491 }492 493 chip->battery = devm_power_supply_register(&client->dev,494 &max17040_battery_desc, &psy_cfg);495 if (IS_ERR(chip->battery)) {496 dev_err(&client->dev, "failed: power supply register\n");497 return PTR_ERR(chip->battery);498 }499 500 ret = max17040_get_version(chip);501 if (ret < 0)502 return ret;503 dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret);504 505 if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041)506 max17040_reset(chip);507 508 max17040_set_rcomp(chip, chip->rcomp);509 510 /* check interrupt */511 if (client->irq && chip->data.has_low_soc_alert) {512 ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert);513 if (ret) {514 dev_err(&client->dev,515 "Failed to set low SOC alert: err %d\n", ret);516 return ret;517 }518 519 enable_irq = true;520 }521 522 if (client->irq && chip->data.has_soc_alert) {523 ret = max17040_set_soc_alert(chip, 1);524 if (ret) {525 dev_err(&client->dev,526 "Failed to set SOC alert: err %d\n", ret);527 return ret;528 }529 enable_irq = true;530 } else {531 /* soc alerts negate the need for polling */532 INIT_DEFERRABLE_WORK(&chip->work, max17040_work);533 ret = devm_add_action(&client->dev, max17040_stop_work, chip);534 if (ret)535 return ret;536 max17040_queue_work(chip);537 }538 539 if (enable_irq) {540 ret = max17040_enable_alert_irq(chip);541 if (ret) {542 client->irq = 0;543 dev_warn(&client->dev,544 "Failed to get IRQ err %d\n", ret);545 }546 }547 548 return 0;549}550 551#ifdef CONFIG_PM_SLEEP552 553static int max17040_suspend(struct device *dev)554{555 struct i2c_client *client = to_i2c_client(dev);556 struct max17040_chip *chip = i2c_get_clientdata(client);557 558 if (client->irq && chip->data.has_soc_alert)559 // disable soc alert to prevent wakeup560 max17040_set_soc_alert(chip, 0);561 else562 cancel_delayed_work(&chip->work);563 564 if (client->irq && device_may_wakeup(dev))565 enable_irq_wake(client->irq);566 567 return 0;568}569 570static int max17040_resume(struct device *dev)571{572 struct i2c_client *client = to_i2c_client(dev);573 struct max17040_chip *chip = i2c_get_clientdata(client);574 575 if (client->irq && device_may_wakeup(dev))576 disable_irq_wake(client->irq);577 578 if (client->irq && chip->data.has_soc_alert)579 max17040_set_soc_alert(chip, 1);580 else581 max17040_queue_work(chip);582 583 return 0;584}585 586static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);587#define MAX17040_PM_OPS (&max17040_pm_ops)588 589#else590 591#define MAX17040_PM_OPS NULL592 593#endif /* CONFIG_PM_SLEEP */594 595static const struct i2c_device_id max17040_id[] = {596 { "max17040", ID_MAX17040 },597 { "max17041", ID_MAX17041 },598 { "max17043", ID_MAX17043 },599 { "max77836-battery", ID_MAX17043 },600 { "max17044", ID_MAX17044 },601 { "max17048", ID_MAX17048 },602 { "max17049", ID_MAX17049 },603 { "max17058", ID_MAX17058 },604 { "max17059", ID_MAX17059 },605 { /* sentinel */ }606};607MODULE_DEVICE_TABLE(i2c, max17040_id);608 609static const struct of_device_id max17040_of_match[] = {610 { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 },611 { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 },612 { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 },613 { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 },614 { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 },615 { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 },616 { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 },617 { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 },618 { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 },619 { /* sentinel */ },620};621MODULE_DEVICE_TABLE(of, max17040_of_match);622 623static struct i2c_driver max17040_i2c_driver = {624 .driver = {625 .name = "max17040",626 .of_match_table = max17040_of_match,627 .pm = MAX17040_PM_OPS,628 },629 .probe = max17040_probe,630 .id_table = max17040_id,631};632module_i2c_driver(max17040_i2c_driver);633 634MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");635MODULE_DESCRIPTION("MAX17040 Fuel Gauge");636MODULE_LICENSE("GPL");637