1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // max17040_battery.c 4 // fuel-gauge systems for lithium-ion (Li+) batteries 5 // 6 // Copyright (C) 2009 Samsung Electronics 7 // 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_device.h> 19 #include <linux/max17040_battery.h> 20 #include <linux/regmap.h> 21 #include <linux/slab.h> 22 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 30 31 32 #define MAX17040_DELAY 1000 33 #define MAX17040_BATTERY_FULL 95 34 #define MAX17040_RCOMP_DEFAULT 0x9700 35 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 42 43 enum 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 */ 55 struct 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 65 static 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 }; 139 140 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; 147 148 /* battery capacity */ 149 int soc; 150 /* State Of Charge */ 151 int status; 152 /* Low alert threshold from 32% to 1% of the State of Charge */ 153 u32 low_soc_alert; 154 /* some devices return twice the capacity */ 155 bool quirk_double_soc; 156 /* higher 8 bits for 17043+, 16 bits for 17040,41 */ 157 u16 rcomp; 158 }; 159 160 static int max17040_reset(struct max17040_chip *chip) 161 { 162 return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val); 163 } 164 165 static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level) 166 { 167 level = 32 - level * (chip->quirk_double_soc ? 2 : 1); 168 return regmap_update_bits(chip->regmap, MAX17040_CONFIG, 169 MAX17040_ATHD_MASK, level); 170 } 171 172 static int max17040_set_soc_alert(struct max17040_chip *chip, bool enable) 173 { 174 return regmap_update_bits(chip->regmap, MAX17040_CONFIG, 175 MAX17040_ALSC_MASK, enable ? MAX17040_ALSC_MASK : 0); 176 } 177 178 static int max17040_set_rcomp(struct max17040_chip *chip, u16 rcomp) 179 { 180 u16 mask = chip->data.rcomp_bytes == 2 ? 181 0xffff : MAX17040_CFG_RCOMP_MASK; 182 183 return regmap_update_bits(chip->regmap, MAX17040_CONFIG, mask, rcomp); 184 } 185 186 static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell) 187 { 188 struct chip_data *d = &chip->data; 189 190 return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div; 191 } 192 193 194 static int max17040_get_vcell(struct max17040_chip *chip) 195 { 196 u32 vcell; 197 198 regmap_read(chip->regmap, MAX17040_VCELL, &vcell); 199 200 return max17040_raw_vcell_to_uvolts(chip, vcell); 201 } 202 203 static int max17040_get_soc(struct max17040_chip *chip) 204 { 205 u32 soc; 206 207 regmap_read(chip->regmap, MAX17040_SOC, &soc); 208 209 return soc >> (chip->quirk_double_soc ? 9 : 8); 210 } 211 212 static int max17040_get_version(struct max17040_chip *chip) 213 { 214 int ret; 215 u32 version; 216 217 ret = regmap_read(chip->regmap, MAX17040_VER, &version); 218 219 return ret ? ret : version; 220 } 221 222 static int max17040_get_online(struct max17040_chip *chip) 223 { 224 return chip->pdata && chip->pdata->battery_online ? 225 chip->pdata->battery_online() : 1; 226 } 227 228 static int max17040_get_status(struct max17040_chip *chip) 229 { 230 if (!chip->pdata || !chip->pdata->charger_online 231 || !chip->pdata->charger_enable) 232 return POWER_SUPPLY_STATUS_UNKNOWN; 233 234 if (max17040_get_soc(chip) > MAX17040_BATTERY_FULL) 235 return POWER_SUPPLY_STATUS_FULL; 236 237 if (chip->pdata->charger_online()) 238 if (chip->pdata->charger_enable()) 239 return POWER_SUPPLY_STATUS_CHARGING; 240 else 241 return POWER_SUPPLY_STATUS_NOT_CHARGING; 242 else 243 return POWER_SUPPLY_STATUS_DISCHARGING; 244 } 245 246 static int max17040_get_of_data(struct max17040_chip *chip) 247 { 248 struct device *dev = &chip->client->dev; 249 struct chip_data *data = &max17040_family[ 250 (uintptr_t) of_device_get_match_data(dev)]; 251 int rcomp_len; 252 u8 rcomp[2]; 253 254 chip->quirk_double_soc = device_property_read_bool(dev, 255 "maxim,double-soc"); 256 257 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); 261 262 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"); 265 return -EINVAL; 266 } 267 268 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", 272 rcomp, rcomp_len); 273 chip->rcomp = rcomp_len == 2 ? 274 rcomp[0] << 8 | rcomp[1] : 275 rcomp[0] << 8; 276 } else if (rcomp_len > 0) { 277 dev_err(dev, "maxim,rcomp has incorrect length\n"); 278 return -EINVAL; 279 } 280 281 return 0; 282 } 283 284 static void max17040_check_changes(struct max17040_chip *chip) 285 { 286 chip->soc = max17040_get_soc(chip); 287 chip->status = max17040_get_status(chip); 288 } 289 290 static void max17040_queue_work(struct max17040_chip *chip) 291 { 292 queue_delayed_work(system_power_efficient_wq, &chip->work, 293 MAX17040_DELAY); 294 } 295 296 static void max17040_stop_work(void *data) 297 { 298 struct max17040_chip *chip = data; 299 300 cancel_delayed_work_sync(&chip->work); 301 } 302 303 static void max17040_work(struct work_struct *work) 304 { 305 struct max17040_chip *chip; 306 int last_soc, last_status; 307 308 chip = container_of(work, struct max17040_chip, work.work); 309 310 /* store SOC and status to check changes */ 311 last_soc = chip->soc; 312 last_status = chip->status; 313 max17040_check_changes(chip); 314 315 /* check changes and send uevent */ 316 if (last_soc != chip->soc || last_status != chip->status) 317 power_supply_changed(chip->battery); 318 319 max17040_queue_work(chip); 320 } 321 322 /* Returns true if alert cause was SOC change, not low SOC */ 323 static bool max17040_handle_soc_alert(struct max17040_chip *chip) 324 { 325 bool ret = true; 326 u32 data; 327 328 regmap_read(chip->regmap, MAX17040_STATUS, &data); 329 330 if (data & MAX17040_STATUS_HD_MASK) { 331 // this alert was caused by low soc 332 ret = false; 333 } 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); 338 } 339 340 return ret; 341 } 342 343 static irqreturn_t max17040_thread_handler(int id, void *dev) 344 { 345 struct max17040_chip *chip = dev; 346 347 if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip))) 348 dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n"); 349 350 /* read registers */ 351 max17040_check_changes(chip); 352 353 /* send uevent */ 354 power_supply_changed(chip->battery); 355 356 /* reset alert bit */ 357 max17040_set_low_soc_alert(chip, chip->low_soc_alert); 358 359 return IRQ_HANDLED; 360 } 361 362 static int max17040_enable_alert_irq(struct max17040_chip *chip) 363 { 364 struct i2c_client *client = chip->client; 365 unsigned int flags; 366 int ret; 367 368 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); 372 373 return ret; 374 } 375 376 static int max17040_prop_writeable(struct power_supply *psy, 377 enum power_supply_property psp) 378 { 379 switch (psp) { 380 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: 381 return 1; 382 default: 383 return 0; 384 } 385 } 386 387 static int max17040_set_property(struct power_supply *psy, 388 enum power_supply_property psp, 389 const union power_supply_propval *val) 390 { 391 struct max17040_chip *chip = power_supply_get_drvdata(psy); 392 int ret; 393 394 switch (psp) { 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))) { 399 ret = -EINVAL; 400 break; 401 } 402 ret = max17040_set_low_soc_alert(chip, val->intval); 403 chip->low_soc_alert = val->intval; 404 break; 405 default: 406 ret = -EINVAL; 407 } 408 409 return ret; 410 } 411 412 static int max17040_get_property(struct power_supply *psy, 413 enum power_supply_property psp, 414 union power_supply_propval *val) 415 { 416 struct max17040_chip *chip = power_supply_get_drvdata(psy); 417 418 switch (psp) { 419 case POWER_SUPPLY_PROP_STATUS: 420 val->intval = max17040_get_status(chip); 421 break; 422 case POWER_SUPPLY_PROP_ONLINE: 423 val->intval = max17040_get_online(chip); 424 break; 425 case POWER_SUPPLY_PROP_VOLTAGE_NOW: 426 val->intval = max17040_get_vcell(chip); 427 break; 428 case POWER_SUPPLY_PROP_CAPACITY: 429 val->intval = max17040_get_soc(chip); 430 break; 431 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: 432 val->intval = chip->low_soc_alert; 433 break; 434 default: 435 return -EINVAL; 436 } 437 return 0; 438 } 439 440 static const struct regmap_config max17040_regmap = { 441 .reg_bits = 8, 442 .reg_stride = 2, 443 .val_bits = 16, 444 .val_format_endian = REGMAP_ENDIAN_BIG, 445 }; 446 447 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, 453 }; 454 455 static const struct power_supply_desc max17040_battery_desc = { 456 .name = "battery", 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), 463 }; 464 465 static int max17040_probe(struct i2c_client *client, 466 const struct i2c_device_id *id) 467 { 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; 473 int ret; 474 475 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 476 return -EIO; 477 478 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 479 if (!chip) 480 return -ENOMEM; 481 482 chip->client = client; 483 chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap); 484 chip->pdata = client->dev.platform_data; 485 chip_id = (enum chip_id) id->driver_data; 486 if (client->dev.of_node) { 487 ret = max17040_get_of_data(chip); 488 if (ret) 489 return ret; 490 chip_id = (enum chip_id) (uintptr_t) 491 of_device_get_match_data(&client->dev); 492 } 493 chip->data = max17040_family[chip_id]; 494 495 i2c_set_clientdata(client, chip); 496 psy_cfg.drv_data = chip; 497 498 chip->battery = devm_power_supply_register(&client->dev, 499 &max17040_battery_desc, &psy_cfg); 500 if (IS_ERR(chip->battery)) { 501 dev_err(&client->dev, "failed: power supply register\n"); 502 return PTR_ERR(chip->battery); 503 } 504 505 ret = max17040_get_version(chip); 506 if (ret < 0) 507 return ret; 508 dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret); 509 510 if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041) 511 max17040_reset(chip); 512 513 max17040_set_rcomp(chip, chip->rcomp); 514 515 /* check interrupt */ 516 if (client->irq && chip->data.has_low_soc_alert) { 517 ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert); 518 if (ret) { 519 dev_err(&client->dev, 520 "Failed to set low SOC alert: err %d\n", ret); 521 return ret; 522 } 523 524 enable_irq = true; 525 } 526 527 if (client->irq && chip->data.has_soc_alert) { 528 ret = max17040_set_soc_alert(chip, 1); 529 if (ret) { 530 dev_err(&client->dev, 531 "Failed to set SOC alert: err %d\n", ret); 532 return ret; 533 } 534 enable_irq = true; 535 } else { 536 /* soc alerts negate the need for polling */ 537 INIT_DEFERRABLE_WORK(&chip->work, max17040_work); 538 ret = devm_add_action(&client->dev, max17040_stop_work, chip); 539 if (ret) 540 return ret; 541 max17040_queue_work(chip); 542 } 543 544 if (enable_irq) { 545 ret = max17040_enable_alert_irq(chip); 546 if (ret) { 547 client->irq = 0; 548 dev_warn(&client->dev, 549 "Failed to get IRQ err %d\n", ret); 550 } 551 } 552 553 return 0; 554 } 555 556 #ifdef CONFIG_PM_SLEEP 557 558 static int max17040_suspend(struct device *dev) 559 { 560 struct i2c_client *client = to_i2c_client(dev); 561 struct max17040_chip *chip = i2c_get_clientdata(client); 562 563 if (client->irq && chip->data.has_soc_alert) 564 // disable soc alert to prevent wakeup 565 max17040_set_soc_alert(chip, 0); 566 else 567 cancel_delayed_work(&chip->work); 568 569 if (client->irq && device_may_wakeup(dev)) 570 enable_irq_wake(client->irq); 571 572 return 0; 573 } 574 575 static int max17040_resume(struct device *dev) 576 { 577 struct i2c_client *client = to_i2c_client(dev); 578 struct max17040_chip *chip = i2c_get_clientdata(client); 579 580 if (client->irq && device_may_wakeup(dev)) 581 disable_irq_wake(client->irq); 582 583 if (client->irq && chip->data.has_soc_alert) 584 max17040_set_soc_alert(chip, 1); 585 else 586 max17040_queue_work(chip); 587 588 return 0; 589 } 590 591 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume); 592 #define MAX17040_PM_OPS (&max17040_pm_ops) 593 594 #else 595 596 #define MAX17040_PM_OPS NULL 597 598 #endif /* CONFIG_PM_SLEEP */ 599 600 static const struct i2c_device_id max17040_id[] = { 601 { "max17040", ID_MAX17040 }, 602 { "max17041", ID_MAX17041 }, 603 { "max17043", ID_MAX17043 }, 604 { "max77836-battery", ID_MAX17043 }, 605 { "max17044", ID_MAX17044 }, 606 { "max17048", ID_MAX17048 }, 607 { "max17049", ID_MAX17049 }, 608 { "max17058", ID_MAX17058 }, 609 { "max17059", ID_MAX17059 }, 610 { /* sentinel */ } 611 }; 612 MODULE_DEVICE_TABLE(i2c, max17040_id); 613 614 static const struct of_device_id max17040_of_match[] = { 615 { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 }, 616 { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 }, 617 { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 }, 618 { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 }, 619 { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 }, 620 { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 }, 621 { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 }, 622 { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 }, 623 { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 }, 624 { /* sentinel */ }, 625 }; 626 MODULE_DEVICE_TABLE(of, max17040_of_match); 627 628 static struct i2c_driver max17040_i2c_driver = { 629 .driver = { 630 .name = "max17040", 631 .of_match_table = max17040_of_match, 632 .pm = MAX17040_PM_OPS, 633 }, 634 .probe = max17040_probe, 635 .id_table = max17040_id, 636 }; 637 module_i2c_driver(max17040_i2c_driver); 638 639 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); 640 MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); 641 MODULE_LICENSE("GPL"); 642