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 if (!device_property_read_u8_array(dev, "maxim,rcomp", 272 rcomp, rcomp_len)) 273 chip->rcomp = rcomp_len == 2 ? rcomp[0] << 8 | rcomp[1] : 274 rcomp[0] << 8; 275 } else if (rcomp_len > 0) { 276 dev_err(dev, "maxim,rcomp has incorrect length\n"); 277 return -EINVAL; 278 } 279 280 return 0; 281 } 282 283 static void max17040_check_changes(struct max17040_chip *chip) 284 { 285 chip->soc = max17040_get_soc(chip); 286 chip->status = max17040_get_status(chip); 287 } 288 289 static void max17040_queue_work(struct max17040_chip *chip) 290 { 291 queue_delayed_work(system_power_efficient_wq, &chip->work, 292 MAX17040_DELAY); 293 } 294 295 static void max17040_stop_work(void *data) 296 { 297 struct max17040_chip *chip = data; 298 299 cancel_delayed_work_sync(&chip->work); 300 } 301 302 static void max17040_work(struct work_struct *work) 303 { 304 struct max17040_chip *chip; 305 int last_soc, last_status; 306 307 chip = container_of(work, struct max17040_chip, work.work); 308 309 /* store SOC and status to check changes */ 310 last_soc = chip->soc; 311 last_status = chip->status; 312 max17040_check_changes(chip); 313 314 /* check changes and send uevent */ 315 if (last_soc != chip->soc || last_status != chip->status) 316 power_supply_changed(chip->battery); 317 318 max17040_queue_work(chip); 319 } 320 321 /* Returns true if alert cause was SOC change, not low SOC */ 322 static bool max17040_handle_soc_alert(struct max17040_chip *chip) 323 { 324 bool ret = true; 325 u32 data; 326 327 regmap_read(chip->regmap, MAX17040_STATUS, &data); 328 329 if (data & MAX17040_STATUS_HD_MASK) { 330 // this alert was caused by low soc 331 ret = false; 332 } 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); 337 } 338 339 return ret; 340 } 341 342 static irqreturn_t max17040_thread_handler(int id, void *dev) 343 { 344 struct max17040_chip *chip = dev; 345 346 if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip))) 347 dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n"); 348 349 /* read registers */ 350 max17040_check_changes(chip); 351 352 /* send uevent */ 353 power_supply_changed(chip->battery); 354 355 /* reset alert bit */ 356 max17040_set_low_soc_alert(chip, chip->low_soc_alert); 357 358 return IRQ_HANDLED; 359 } 360 361 static int max17040_enable_alert_irq(struct max17040_chip *chip) 362 { 363 struct i2c_client *client = chip->client; 364 unsigned int flags; 365 int ret; 366 367 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); 371 372 return ret; 373 } 374 375 static int max17040_prop_writeable(struct power_supply *psy, 376 enum power_supply_property psp) 377 { 378 switch (psp) { 379 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: 380 return 1; 381 default: 382 return 0; 383 } 384 } 385 386 static int max17040_set_property(struct power_supply *psy, 387 enum power_supply_property psp, 388 const union power_supply_propval *val) 389 { 390 struct max17040_chip *chip = power_supply_get_drvdata(psy); 391 int ret; 392 393 switch (psp) { 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))) { 398 ret = -EINVAL; 399 break; 400 } 401 ret = max17040_set_low_soc_alert(chip, val->intval); 402 chip->low_soc_alert = val->intval; 403 break; 404 default: 405 ret = -EINVAL; 406 } 407 408 return ret; 409 } 410 411 static int max17040_get_property(struct power_supply *psy, 412 enum power_supply_property psp, 413 union power_supply_propval *val) 414 { 415 struct max17040_chip *chip = power_supply_get_drvdata(psy); 416 417 switch (psp) { 418 case POWER_SUPPLY_PROP_STATUS: 419 val->intval = max17040_get_status(chip); 420 break; 421 case POWER_SUPPLY_PROP_ONLINE: 422 val->intval = max17040_get_online(chip); 423 break; 424 case POWER_SUPPLY_PROP_VOLTAGE_NOW: 425 val->intval = max17040_get_vcell(chip); 426 break; 427 case POWER_SUPPLY_PROP_CAPACITY: 428 val->intval = max17040_get_soc(chip); 429 break; 430 case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: 431 val->intval = chip->low_soc_alert; 432 break; 433 default: 434 return -EINVAL; 435 } 436 return 0; 437 } 438 439 static const struct regmap_config max17040_regmap = { 440 .reg_bits = 8, 441 .reg_stride = 2, 442 .val_bits = 16, 443 .val_format_endian = REGMAP_ENDIAN_BIG, 444 }; 445 446 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, 452 }; 453 454 static const struct power_supply_desc max17040_battery_desc = { 455 .name = "battery", 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), 462 }; 463 464 static int max17040_probe(struct i2c_client *client, 465 const struct i2c_device_id *id) 466 { 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; 472 int ret; 473 474 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 475 return -EIO; 476 477 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 478 if (!chip) 479 return -ENOMEM; 480 481 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); 487 if (ret) 488 return ret; 489 chip_id = (uintptr_t)of_device_get_match_data(&client->dev); 490 } 491 chip->data = max17040_family[chip_id]; 492 493 i2c_set_clientdata(client, chip); 494 psy_cfg.drv_data = chip; 495 496 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); 501 } 502 503 ret = max17040_get_version(chip); 504 if (ret < 0) 505 return ret; 506 dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret); 507 508 if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041) 509 max17040_reset(chip); 510 511 max17040_set_rcomp(chip, chip->rcomp); 512 513 /* check interrupt */ 514 if (client->irq && chip->data.has_low_soc_alert) { 515 ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert); 516 if (ret) { 517 dev_err(&client->dev, 518 "Failed to set low SOC alert: err %d\n", ret); 519 return ret; 520 } 521 522 enable_irq = true; 523 } 524 525 if (client->irq && chip->data.has_soc_alert) { 526 ret = max17040_set_soc_alert(chip, 1); 527 if (ret) { 528 dev_err(&client->dev, 529 "Failed to set SOC alert: err %d\n", ret); 530 return ret; 531 } 532 enable_irq = true; 533 } else { 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); 537 if (ret) 538 return ret; 539 max17040_queue_work(chip); 540 } 541 542 if (enable_irq) { 543 ret = max17040_enable_alert_irq(chip); 544 if (ret) { 545 client->irq = 0; 546 dev_warn(&client->dev, 547 "Failed to get IRQ err %d\n", ret); 548 } 549 } 550 551 return 0; 552 } 553 554 #ifdef CONFIG_PM_SLEEP 555 556 static int max17040_suspend(struct device *dev) 557 { 558 struct i2c_client *client = to_i2c_client(dev); 559 struct max17040_chip *chip = i2c_get_clientdata(client); 560 561 if (client->irq && chip->data.has_soc_alert) 562 // disable soc alert to prevent wakeup 563 max17040_set_soc_alert(chip, 0); 564 else 565 cancel_delayed_work(&chip->work); 566 567 if (client->irq && device_may_wakeup(dev)) 568 enable_irq_wake(client->irq); 569 570 return 0; 571 } 572 573 static int max17040_resume(struct device *dev) 574 { 575 struct i2c_client *client = to_i2c_client(dev); 576 struct max17040_chip *chip = i2c_get_clientdata(client); 577 578 if (client->irq && device_may_wakeup(dev)) 579 disable_irq_wake(client->irq); 580 581 if (client->irq && chip->data.has_soc_alert) 582 max17040_set_soc_alert(chip, 1); 583 else 584 max17040_queue_work(chip); 585 586 return 0; 587 } 588 589 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume); 590 #define MAX17040_PM_OPS (&max17040_pm_ops) 591 592 #else 593 594 #define MAX17040_PM_OPS NULL 595 596 #endif /* CONFIG_PM_SLEEP */ 597 598 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 }, 608 { /* sentinel */ } 609 }; 610 MODULE_DEVICE_TABLE(i2c, max17040_id); 611 612 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 }, 622 { /* sentinel */ }, 623 }; 624 MODULE_DEVICE_TABLE(of, max17040_of_match); 625 626 static struct i2c_driver max17040_i2c_driver = { 627 .driver = { 628 .name = "max17040", 629 .of_match_table = max17040_of_match, 630 .pm = MAX17040_PM_OPS, 631 }, 632 .probe = max17040_probe, 633 .id_table = max17040_id, 634 }; 635 module_i2c_driver(max17040_i2c_driver); 636 637 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); 638 MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); 639 MODULE_LICENSE("GPL"); 640