drivers/power/supply/max17040_battery.c

   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");