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.h> 19 #include <linux/regmap.h> 20 #include <linux/slab.h> 21 #include <linux/iio/consumer.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 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 }; 157 158 static int max17040_reset(struct max17040_chip *chip) 159 { 160 return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val); 161 } 162 163 static 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 } 169 170 static 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 } 175 176 static 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 } 183 184 static 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 } 190 191 192 static 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 } 200 201 static 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 } 209 210 static 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 } 219 220 static int max17040_get_online(struct max17040_chip *chip) 221 { 222 return 1; 223 } 224 225 static 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 } 261 262 static void max17040_check_changes(struct max17040_chip *chip) 263 { 264 chip->soc = max17040_get_soc(chip); 265 } 266 267 static void max17040_queue_work(struct max17040_chip *chip) 268 { 269 queue_delayed_work(system_power_efficient_wq, &chip->work, 270 MAX17040_DELAY); 271 } 272 273 static void max17040_stop_work(void *data) 274 { 275 struct max17040_chip *chip = data; 276 277 cancel_delayed_work_sync(&chip->work); 278 } 279 280 static 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 */ 299 static 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 soc 308 ret = false; 309 } 310 if (data & MAX17040_STATUS_SC_MASK) { 311 // soc change bit -- deassert to mark as handled 312 regmap_write(chip->regmap, MAX17040_STATUS, 313 data & ~MAX17040_STATUS_SC_MASK); 314 } 315 316 return ret; 317 } 318 319 static 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 } 337 338 static 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 } 349 350 static 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 } 360 361 static 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 } 385 386 static 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 } 421 422 static 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 }; 428 429 static 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 }; 438 439 static 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 }; 448 449 static 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 else 490 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_SLEEP 552 553 static 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 wakeup 560 max17040_set_soc_alert(chip, 0); 561 else 562 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 } 569 570 static 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 else 581 max17040_queue_work(chip); 582 583 return 0; 584 } 585 586 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume); 587 #define MAX17040_PM_OPS (&max17040_pm_ops) 588 589 #else 590 591 #define MAX17040_PM_OPS NULL 592 593 #endif /* CONFIG_PM_SLEEP */ 594 595 static 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 }; 607 MODULE_DEVICE_TABLE(i2c, max17040_id); 608 609 static 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 }; 621 MODULE_DEVICE_TABLE(of, max17040_of_match); 622 623 static 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 }; 632 module_i2c_driver(max17040_i2c_driver); 633 634 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); 635 MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); 636 MODULE_LICENSE("GPL"); 637