drivers/power/supply/ltc2941-battery-gauge.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * I2C client/driver for the Linear Technology LTC2941, LTC2942, LTC2943
   4  * and LTC2944 Battery Gas Gauge IC
   5  *
   6  * Copyright (C) 2014 Topic Embedded Systems
   7  *
   8  * Author: Auryn Verwegen
   9  * Author: Mike Looijmans
  10  */
  11 #include <linux/devm-helpers.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/swab.h>
  18 #include <linux/i2c.h>
  19 #include <linux/delay.h>
  20 #include <linux/power_supply.h>
  21 #include <linux/slab.h>
  22
  23 #define I16_MSB(x)                      ((x >> 8) & 0xFF)
  24 #define I16_LSB(x)                      (x & 0xFF)
  25
  26 #define LTC294X_WORK_DELAY              10      /* Update delay in seconds */
  27
  28 #define LTC294X_MAX_VALUE               0xFFFF
  29 #define LTC294X_MID_SUPPLY              0x7FFF
  30
  31 #define LTC2941_MAX_PRESCALER_EXP       7
  32 #define LTC2943_MAX_PRESCALER_EXP       6
  33
  34 enum ltc294x_reg {
  35         LTC294X_REG_STATUS              = 0x00,
  36         LTC294X_REG_CONTROL             = 0x01,
  37         LTC294X_REG_ACC_CHARGE_MSB      = 0x02,
  38         LTC294X_REG_ACC_CHARGE_LSB      = 0x03,
  39         LTC294X_REG_CHARGE_THR_HIGH_MSB = 0x04,
  40         LTC294X_REG_CHARGE_THR_HIGH_LSB = 0x05,
  41         LTC294X_REG_CHARGE_THR_LOW_MSB  = 0x06,
  42         LTC294X_REG_CHARGE_THR_LOW_LSB  = 0x07,
  43         LTC294X_REG_VOLTAGE_MSB         = 0x08,
  44         LTC294X_REG_VOLTAGE_LSB         = 0x09,
  45         LTC2942_REG_TEMPERATURE_MSB     = 0x0C,
  46         LTC2942_REG_TEMPERATURE_LSB     = 0x0D,
  47         LTC2943_REG_CURRENT_MSB         = 0x0E,
  48         LTC2943_REG_CURRENT_LSB         = 0x0F,
  49         LTC2943_REG_TEMPERATURE_MSB     = 0x14,
  50         LTC2943_REG_TEMPERATURE_LSB     = 0x15,
  51 };
  52
  53 enum ltc294x_id {
  54         LTC2941_ID,
  55         LTC2942_ID,
  56         LTC2943_ID,
  57         LTC2944_ID,
  58 };
  59
  60 #define LTC2941_REG_STATUS_CHIP_ID      BIT(7)
  61
  62 #define LTC2942_REG_CONTROL_MODE_SCAN   (BIT(7) | BIT(6))
  63 #define LTC2943_REG_CONTROL_MODE_SCAN   BIT(7)
  64 #define LTC294X_REG_CONTROL_PRESCALER_MASK      (BIT(5) | BIT(4) | BIT(3))
  65 #define LTC294X_REG_CONTROL_SHUTDOWN_MASK       (BIT(0))
  66 #define LTC294X_REG_CONTROL_PRESCALER_SET(x) \
  67         ((x << 3) & LTC294X_REG_CONTROL_PRESCALER_MASK)
  68 #define LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED        0
  69 #define LTC294X_REG_CONTROL_ADC_DISABLE(x)      ((x) & ~(BIT(7) | BIT(6)))
  70
  71 struct ltc294x_info {
  72         struct i2c_client *client;      /* I2C Client pointer */
  73         struct power_supply *supply;    /* Supply pointer */
  74         struct power_supply_desc supply_desc;   /* Supply description */
  75         struct delayed_work work;       /* Work scheduler */
  76         enum ltc294x_id id;             /* Chip type */
  77         int charge;     /* Last charge register content */
  78         int r_sense;    /* mOhm */
  79         int Qlsb;       /* nAh */
  80 };
  81
  82 static inline int convert_bin_to_uAh(
  83         const struct ltc294x_info *info, int Q)
  84 {
  85         return ((Q * (info->Qlsb / 10))) / 100;
  86 }
  87
  88 static inline int convert_uAh_to_bin(
  89         const struct ltc294x_info *info, int uAh)
  90 {
  91         int Q;
  92
  93         Q = (uAh * 100) / (info->Qlsb/10);
  94         return (Q < LTC294X_MAX_VALUE) ? Q : LTC294X_MAX_VALUE;
  95 }
  96
  97 static int ltc294x_read_regs(struct i2c_client *client,
  98         enum ltc294x_reg reg, u8 *buf, int num_regs)
  99 {
 100         int ret;
 101         struct i2c_msg msgs[2] = { };
 102         u8 reg_start = reg;
 103
 104         msgs[0].addr    = client->addr;
 105         msgs[0].len     = 1;
 106         msgs[0].buf     = &reg_start;
 107
 108         msgs[1].addr    = client->addr;
 109         msgs[1].len     = num_regs;
 110         msgs[1].buf     = buf;
 111         msgs[1].flags   = I2C_M_RD;
 112
 113         ret = i2c_transfer(client->adapter, &msgs[0], 2);
 114         if (ret < 0) {
 115                 dev_err(&client->dev, "ltc2941 read_reg(0x%x[%d]) failed: %pe\n",
 116                         reg, num_regs, ERR_PTR(ret));
 117                 return ret;
 118         }
 119
 120         dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
 121                 __func__, reg, num_regs, *buf);
 122
 123         return 0;
 124 }
 125
 126 static int ltc294x_write_regs(struct i2c_client *client,
 127         enum ltc294x_reg reg, const u8 *buf, int num_regs)
 128 {
 129         int ret;
 130         u8 reg_start = reg;
 131
 132         ret = i2c_smbus_write_i2c_block_data(client, reg_start, num_regs, buf);
 133         if (ret < 0) {
 134                 dev_err(&client->dev, "ltc2941 write_reg(0x%x[%d]) failed: %pe\n",
 135                         reg, num_regs, ERR_PTR(ret));
 136                 return ret;
 137         }
 138
 139         dev_dbg(&client->dev, "%s (%#x, %d) -> %#x\n",
 140                 __func__, reg, num_regs, *buf);
 141
 142         return 0;
 143 }
 144
 145 static int ltc294x_reset(const struct ltc294x_info *info, int prescaler_exp)
 146 {
 147         int ret;
 148         u8 value;
 149         u8 control;
 150
 151         /* Read status and control registers */
 152         ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
 153         if (ret < 0)
 154                 return ret;
 155
 156         control = LTC294X_REG_CONTROL_PRESCALER_SET(prescaler_exp) |
 157                                 LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED;
 158         /* Put device into "monitor" mode */
 159         switch (info->id) {
 160         case LTC2942_ID:        /* 2942 measures every 2 sec */
 161                 control |= LTC2942_REG_CONTROL_MODE_SCAN;
 162                 break;
 163         case LTC2943_ID:
 164         case LTC2944_ID:        /* 2943 and 2944 measure every 10 sec */
 165                 control |= LTC2943_REG_CONTROL_MODE_SCAN;
 166                 break;
 167         default:
 168                 break;
 169         }
 170
 171         if (value != control) {
 172                 ret = ltc294x_write_regs(info->client,
 173                         LTC294X_REG_CONTROL, &control, 1);
 174                 if (ret < 0)
 175                         return ret;
 176         }
 177
 178         return 0;
 179 }
 180
 181 static int ltc294x_read_charge_register(const struct ltc294x_info *info,
 182                                         enum ltc294x_reg reg)
 183  {
 184         int ret;
 185         u8 datar[2];
 186
 187         ret = ltc294x_read_regs(info->client, reg, &datar[0], 2);
 188         if (ret < 0)
 189                 return ret;
 190         return (datar[0] << 8) + datar[1];
 191 }
 192
 193 static int ltc294x_get_charge(const struct ltc294x_info *info,
 194                                 enum ltc294x_reg reg, int *val)
 195 {
 196         int value = ltc294x_read_charge_register(info, reg);
 197
 198         if (value < 0)
 199                 return value;
 200         /* When r_sense < 0, this counts up when the battery discharges */
 201         if (info->Qlsb < 0)
 202                 value -= 0xFFFF;
 203         *val = convert_bin_to_uAh(info, value);
 204         return 0;
 205 }
 206
 207 static int ltc294x_set_charge_now(const struct ltc294x_info *info, int val)
 208 {
 209         int ret;
 210         u8 dataw[2];
 211         u8 ctrl_reg;
 212         s32 value;
 213
 214         value = convert_uAh_to_bin(info, val);
 215         /* Direction depends on how sense+/- were connected */
 216         if (info->Qlsb < 0)
 217                 value += 0xFFFF;
 218         if ((value < 0) || (value > 0xFFFF)) /* input validation */
 219                 return -EINVAL;
 220
 221         /* Read control register */
 222         ret = ltc294x_read_regs(info->client,
 223                 LTC294X_REG_CONTROL, &ctrl_reg, 1);
 224         if (ret < 0)
 225                 return ret;
 226         /* Disable analog section */
 227         ctrl_reg |= LTC294X_REG_CONTROL_SHUTDOWN_MASK;
 228         ret = ltc294x_write_regs(info->client,
 229                 LTC294X_REG_CONTROL, &ctrl_reg, 1);
 230         if (ret < 0)
 231                 return ret;
 232         /* Set new charge value */
 233         dataw[0] = I16_MSB(value);
 234         dataw[1] = I16_LSB(value);
 235         ret = ltc294x_write_regs(info->client,
 236                 LTC294X_REG_ACC_CHARGE_MSB, &dataw[0], 2);
 237         if (ret < 0)
 238                 goto error_exit;
 239         /* Enable analog section */
 240 error_exit:
 241         ctrl_reg &= ~LTC294X_REG_CONTROL_SHUTDOWN_MASK;
 242         ret = ltc294x_write_regs(info->client,
 243                 LTC294X_REG_CONTROL, &ctrl_reg, 1);
 244
 245         return ret < 0 ? ret : 0;
 246 }
 247
 248 static int ltc294x_set_charge_thr(const struct ltc294x_info *info,
 249                                         enum ltc294x_reg reg, int val)
 250 {
 251         u8 dataw[2];
 252         s32 value;
 253
 254         value = convert_uAh_to_bin(info, val);
 255         /* Direction depends on how sense+/- were connected */
 256         if (info->Qlsb < 0)
 257                 value += 0xFFFF;
 258         if ((value < 0) || (value > 0xFFFF)) /* input validation */
 259                 return -EINVAL;
 260
 261         /* Set new charge value */
 262         dataw[0] = I16_MSB(value);
 263         dataw[1] = I16_LSB(value);
 264         return ltc294x_write_regs(info->client, reg, &dataw[0], 2);
 265 }
 266
 267 static int ltc294x_get_charge_counter(
 268         const struct ltc294x_info *info, int *val)
 269 {
 270         int value = ltc294x_read_charge_register(info, LTC294X_REG_ACC_CHARGE_MSB);
 271
 272         if (value < 0)
 273                 return value;
 274         value -= LTC294X_MID_SUPPLY;
 275         *val = convert_bin_to_uAh(info, value);
 276         return 0;
 277 }
 278
 279 static int ltc294x_get_voltage(const struct ltc294x_info *info, int *val)
 280 {
 281         int ret;
 282         u8 datar[2];
 283         u32 value;
 284
 285         ret = ltc294x_read_regs(info->client,
 286                 LTC294X_REG_VOLTAGE_MSB, &datar[0], 2);
 287         value = (datar[0] << 8) | datar[1];
 288         switch (info->id) {
 289         case LTC2943_ID:
 290                 value *= 23600 * 2;
 291                 value /= 0xFFFF;
 292                 value *= 1000 / 2;
 293                 break;
 294         case LTC2944_ID:
 295                 value *= 70800 / 5*4;
 296                 value /= 0xFFFF;
 297                 value *= 1000 * 5/4;
 298                 break;
 299         default:
 300                 value *= 6000 * 10;
 301                 value /= 0xFFFF;
 302                 value *= 1000 / 10;
 303                 break;
 304         }
 305         *val = value;
 306         return ret;
 307 }
 308
 309 static int ltc294x_get_current(const struct ltc294x_info *info, int *val)
 310 {
 311         int ret;
 312         u8 datar[2];
 313         s32 value;
 314
 315         ret = ltc294x_read_regs(info->client,
 316                 LTC2943_REG_CURRENT_MSB, &datar[0], 2);
 317         value = (datar[0] << 8) | datar[1];
 318         value -= 0x7FFF;
 319         if (info->id == LTC2944_ID)
 320                 value *= 64000;
 321         else
 322                 value *= 60000;
 323         /* Value is in range -32k..+32k, r_sense is usually 10..50 mOhm,
 324          * the formula below keeps everything in s32 range while preserving
 325          * enough digits */
 326         *val = 1000 * (value / (info->r_sense * 0x7FFF)); /* in uA */
 327         return ret;
 328 }
 329
 330 static int ltc294x_get_temperature(const struct ltc294x_info *info, int *val)
 331 {
 332         enum ltc294x_reg reg;
 333         int ret;
 334         u8 datar[2];
 335         u32 value;
 336
 337         if (info->id == LTC2942_ID) {
 338                 reg = LTC2942_REG_TEMPERATURE_MSB;
 339                 value = 6000;   /* Full-scale is 600 Kelvin */
 340         } else {
 341                 reg = LTC2943_REG_TEMPERATURE_MSB;
 342                 value = 5100;   /* Full-scale is 510 Kelvin */
 343         }
 344         ret = ltc294x_read_regs(info->client, reg, &datar[0], 2);
 345         value *= (datar[0] << 8) | datar[1];
 346         /* Convert to tenths of degree Celsius */
 347         *val = value / 0xFFFF - 2722;
 348         return ret;
 349 }
 350
 351 static int ltc294x_get_property(struct power_supply *psy,
 352                                 enum power_supply_property prop,
 353                                 union power_supply_propval *val)
 354 {
 355         struct ltc294x_info *info = power_supply_get_drvdata(psy);
 356
 357         switch (prop) {
 358         case POWER_SUPPLY_PROP_CHARGE_FULL:
 359                 return ltc294x_get_charge(info, LTC294X_REG_CHARGE_THR_HIGH_MSB,
 360                                                 &val->intval);
 361         case POWER_SUPPLY_PROP_CHARGE_EMPTY:
 362                 return ltc294x_get_charge(info, LTC294X_REG_CHARGE_THR_LOW_MSB,
 363                                                 &val->intval);
 364         case POWER_SUPPLY_PROP_CHARGE_NOW:
 365                 return ltc294x_get_charge(info, LTC294X_REG_ACC_CHARGE_MSB,
 366                                                 &val->intval);
 367         case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 368                 return ltc294x_get_charge_counter(info, &val->intval);
 369         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 370                 return ltc294x_get_voltage(info, &val->intval);
 371         case POWER_SUPPLY_PROP_CURRENT_NOW:
 372                 return ltc294x_get_current(info, &val->intval);
 373         case POWER_SUPPLY_PROP_TEMP:
 374                 return ltc294x_get_temperature(info, &val->intval);
 375         default:
 376                 return -EINVAL;
 377         }
 378 }
 379
 380 static int ltc294x_set_property(struct power_supply *psy,
 381         enum power_supply_property psp,
 382         const union power_supply_propval *val)
 383 {
 384         struct ltc294x_info *info = power_supply_get_drvdata(psy);
 385
 386         switch (psp) {
 387         case POWER_SUPPLY_PROP_CHARGE_FULL:
 388                 return ltc294x_set_charge_thr(info,
 389                         LTC294X_REG_CHARGE_THR_HIGH_MSB, val->intval);
 390         case POWER_SUPPLY_PROP_CHARGE_EMPTY:
 391                 return ltc294x_set_charge_thr(info,
 392                         LTC294X_REG_CHARGE_THR_LOW_MSB, val->intval);
 393         case POWER_SUPPLY_PROP_CHARGE_NOW:
 394                 return ltc294x_set_charge_now(info, val->intval);
 395         default:
 396                 return -EPERM;
 397         }
 398 }
 399
 400 static int ltc294x_property_is_writeable(
 401         struct power_supply *psy, enum power_supply_property psp)
 402 {
 403         switch (psp) {
 404         case POWER_SUPPLY_PROP_CHARGE_FULL:
 405         case POWER_SUPPLY_PROP_CHARGE_EMPTY:
 406         case POWER_SUPPLY_PROP_CHARGE_NOW:
 407                 return 1;
 408         default:
 409                 return 0;
 410         }
 411 }
 412
 413 static void ltc294x_update(struct ltc294x_info *info)
 414 {
 415         int charge = ltc294x_read_charge_register(info, LTC294X_REG_ACC_CHARGE_MSB);
 416
 417         if (charge != info->charge) {
 418                 info->charge = charge;
 419                 power_supply_changed(info->supply);
 420         }
 421 }
 422
 423 static void ltc294x_work(struct work_struct *work)
 424 {
 425         struct ltc294x_info *info;
 426
 427         info = container_of(work, struct ltc294x_info, work.work);
 428         ltc294x_update(info);
 429         schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
 430 }
 431
 432 static enum power_supply_property ltc294x_properties[] = {
 433         POWER_SUPPLY_PROP_CHARGE_COUNTER,
 434         POWER_SUPPLY_PROP_CHARGE_FULL,
 435         POWER_SUPPLY_PROP_CHARGE_EMPTY,
 436         POWER_SUPPLY_PROP_CHARGE_NOW,
 437         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 438         POWER_SUPPLY_PROP_TEMP,
 439         POWER_SUPPLY_PROP_CURRENT_NOW,
 440 };
 441
 442 static int ltc294x_i2c_probe(struct i2c_client *client)
 443 {
 444         struct power_supply_config psy_cfg = {};
 445         struct ltc294x_info *info;
 446         struct device_node *np;
 447         int ret;
 448         u32 prescaler_exp;
 449         s32 r_sense;
 450         u8 status;
 451
 452         info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
 453         if (info == NULL)
 454                 return -ENOMEM;
 455
 456         i2c_set_clientdata(client, info);
 457
 458         np = of_node_get(client->dev.of_node);
 459
 460         info->id = (enum ltc294x_id) (uintptr_t) of_device_get_match_data(
 461                                                         &client->dev);
 462         info->supply_desc.name = np->name;
 463
 464         /* r_sense can be negative, when sense+ is connected to the battery
 465          * instead of the sense-. This results in reversed measurements. */
 466         ret = of_property_read_u32(np, "lltc,resistor-sense", &r_sense);
 467         if (ret < 0)
 468                 return dev_err_probe(&client->dev, ret,
 469                         "Could not find lltc,resistor-sense in devicetree\n");
 470         info->r_sense = r_sense;
 471
 472         ret = of_property_read_u32(np, "lltc,prescaler-exponent",
 473                 &prescaler_exp);
 474         if (ret < 0) {
 475                 dev_warn(&client->dev,
 476                         "lltc,prescaler-exponent not in devicetree\n");
 477                 prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
 478         }
 479
 480         if (info->id == LTC2943_ID) {
 481                 if (prescaler_exp > LTC2943_MAX_PRESCALER_EXP)
 482                         prescaler_exp = LTC2943_MAX_PRESCALER_EXP;
 483                 info->Qlsb = ((340 * 50000) / r_sense) >>
 484                              (12 - 2*prescaler_exp);
 485         } else {
 486                 if (prescaler_exp > LTC2941_MAX_PRESCALER_EXP)
 487                         prescaler_exp = LTC2941_MAX_PRESCALER_EXP;
 488                 info->Qlsb = ((85 * 50000) / r_sense) >>
 489                              (7 - prescaler_exp);
 490         }
 491
 492         /* Read status register to check for LTC2942 */
 493         if (info->id == LTC2941_ID || info->id == LTC2942_ID) {
 494                 ret = ltc294x_read_regs(client, LTC294X_REG_STATUS, &status, 1);
 495                 if (ret < 0)
 496                         return dev_err_probe(&client->dev, ret,
 497                                 "Could not read status register\n");
 498                 if (status & LTC2941_REG_STATUS_CHIP_ID)
 499                         info->id = LTC2941_ID;
 500                 else
 501                         info->id = LTC2942_ID;
 502         }
 503
 504         info->client = client;
 505         info->supply_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 506         info->supply_desc.properties = ltc294x_properties;
 507         switch (info->id) {
 508         case LTC2944_ID:
 509         case LTC2943_ID:
 510                 info->supply_desc.num_properties =
 511                         ARRAY_SIZE(ltc294x_properties);
 512                 break;
 513         case LTC2942_ID:
 514                 info->supply_desc.num_properties =
 515                         ARRAY_SIZE(ltc294x_properties) - 1;
 516                 break;
 517         case LTC2941_ID:
 518         default:
 519                 info->supply_desc.num_properties =
 520                         ARRAY_SIZE(ltc294x_properties) - 3;
 521                 break;
 522         }
 523         info->supply_desc.get_property = ltc294x_get_property;
 524         info->supply_desc.set_property = ltc294x_set_property;
 525         info->supply_desc.property_is_writeable = ltc294x_property_is_writeable;
 526         info->supply_desc.external_power_changed        = NULL;
 527
 528         psy_cfg.drv_data = info;
 529
 530         ret = devm_delayed_work_autocancel(&client->dev, &info->work,
 531                                            ltc294x_work);
 532         if (ret)
 533                 return ret;
 534
 535         ret = ltc294x_reset(info, prescaler_exp);
 536         if (ret < 0)
 537                 return dev_err_probe(&client->dev, ret,
 538                         "Communication with chip failed\n");
 539
 540         info->supply = devm_power_supply_register(&client->dev,
 541                                                   &info->supply_desc, &psy_cfg);
 542         if (IS_ERR(info->supply))
 543                 return dev_err_probe(&client->dev, PTR_ERR(info->supply),
 544                         "failed to register ltc2941\n");
 545
 546         schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
 547
 548         return 0;
 549 }
 550
 551 static void ltc294x_i2c_shutdown(struct i2c_client *client)
 552 {
 553         struct ltc294x_info *info = i2c_get_clientdata(client);
 554         int ret;
 555         u8 value;
 556         u8 control;
 557
 558         /* The LTC2941 does not need any special handling */
 559         if (info->id == LTC2941_ID)
 560                 return;
 561
 562         /* Read control register */
 563         ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1);
 564         if (ret < 0)
 565                 return;
 566
 567         /* Disable continuous ADC conversion as this drains the battery */
 568         control = LTC294X_REG_CONTROL_ADC_DISABLE(value);
 569         if (control != value)
 570                 ltc294x_write_regs(info->client, LTC294X_REG_CONTROL,
 571                         &control, 1);
 572 }
 573
 574 #ifdef CONFIG_PM_SLEEP
 575
 576 static int ltc294x_suspend(struct device *dev)
 577 {
 578         struct i2c_client *client = to_i2c_client(dev);
 579         struct ltc294x_info *info = i2c_get_clientdata(client);
 580
 581         cancel_delayed_work(&info->work);
 582         return 0;
 583 }
 584
 585 static int ltc294x_resume(struct device *dev)
 586 {
 587         struct i2c_client *client = to_i2c_client(dev);
 588         struct ltc294x_info *info = i2c_get_clientdata(client);
 589
 590         schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
 591         return 0;
 592 }
 593
 594 static SIMPLE_DEV_PM_OPS(ltc294x_pm_ops, ltc294x_suspend, ltc294x_resume);
 595 #define LTC294X_PM_OPS (&ltc294x_pm_ops)
 596
 597 #else
 598 #define LTC294X_PM_OPS NULL
 599 #endif /* CONFIG_PM_SLEEP */
 600
 601
 602 static const struct i2c_device_id ltc294x_i2c_id[] = {
 603         { "ltc2941", LTC2941_ID, },
 604         { "ltc2942", LTC2942_ID, },
 605         { "ltc2943", LTC2943_ID, },
 606         { "ltc2944", LTC2944_ID, },
 607         { },
 608 };
 609 MODULE_DEVICE_TABLE(i2c, ltc294x_i2c_id);
 610
 611 static const struct of_device_id ltc294x_i2c_of_match[] = {
 612         {
 613                 .compatible = "lltc,ltc2941",
 614                 .data = (void *)LTC2941_ID,
 615         },
 616         {
 617                 .compatible = "lltc,ltc2942",
 618                 .data = (void *)LTC2942_ID,
 619         },
 620         {
 621                 .compatible = "lltc,ltc2943",
 622                 .data = (void *)LTC2943_ID,
 623         },
 624         {
 625                 .compatible = "lltc,ltc2944",
 626                 .data = (void *)LTC2944_ID,
 627         },
 628         { },
 629 };
 630 MODULE_DEVICE_TABLE(of, ltc294x_i2c_of_match);
 631
 632 static struct i2c_driver ltc294x_driver = {
 633         .driver = {
 634                 .name   = "LTC2941",
 635                 .of_match_table = ltc294x_i2c_of_match,
 636                 .pm     = LTC294X_PM_OPS,
 637         },
 638         .probe          = ltc294x_i2c_probe,
 639         .shutdown       = ltc294x_i2c_shutdown,
 640         .id_table       = ltc294x_i2c_id,
 641 };
 642 module_i2c_driver(ltc294x_driver);
 643
 644 MODULE_AUTHOR("Auryn Verwegen, Topic Embedded Systems");
 645 MODULE_AUTHOR("Mike Looijmans, Topic Embedded Products");
 646 MODULE_DESCRIPTION("LTC2941/LTC2942/LTC2943/LTC2944 Battery Gas Gauge IC driver");
 647 MODULE_LICENSE("GPL");