drivers/power/bq27x00_battery.c

   1 /*
   2  * linux/drivers/power/bq27x00_battery.c
   3  *
   4  * BQ27000/BQ27200 battery driver
   5  *
   6  * Copyright (C) 2008 Texas Instruments, Inc.
   7  *
   8  * Author: Texas Instruments
   9  *
  10  * This package is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  16  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  */
  19 #include <linux/module.h>
  20 #include <linux/param.h>
  21 #include <linux/jiffies.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/delay.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/power_supply.h>
  26
  27 #ifdef CONFIG_BATTERY_BQ27000
  28 #include "../w1/w1.h"
  29 #endif
  30 #ifdef CONFIG_BATTERY_BQ27200
  31 #include <linux/i2c.h>
  32 #endif
  33
  34 #define BQ27x00_REG_TEMP                0x06
  35 #define BQ27x00_REG_VOLT                0x08
  36 #define BQ27x00_REG_RSOC                0x0B /* Relative State-of-Charge */
  37 #define BQ27x00_REG_AI                  0x14
  38 #define BQ27x00_REG_FLAGS               0x0A
  39 #define HIGH_BYTE(A)                    ((A) << 8)
  40
  41 #ifdef CONFIG_BATTERY_BQ27000
  42 extern int w1_bq27000_read(struct device *dev, u8 reg);
  43 #endif
  44
  45 struct bq27x00_device_info;
  46 struct bq27x00_access_methods {
  47         int (*read)(u8 reg, int *rt_value, int b_single,
  48                 struct bq27x00_device_info *di);
  49 };
  50
  51 struct bq27x00_device_info {
  52         struct device           *dev;
  53 #ifdef CONFIG_BATTERY_BQ27000
  54         struct device           *w1_dev;
  55 #endif
  56 #ifdef CONFIG_BATTERY_BQ27200
  57         struct i2c_client *client;
  58 #endif
  59         unsigned long           update_time;
  60         int                     voltage_uV;
  61         int                     current_uA;
  62         int                     temp_C;
  63         int                     charge_rsoc;
  64         struct bq27x00_access_methods   *bus;
  65         struct power_supply     bat;
  66         struct delayed_work     monitor_work;
  67 };
  68
  69 static unsigned int cache_time = 60000;
  70 module_param(cache_time, uint, 0644);
  71 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
  72
  73 static enum power_supply_property bq27x00_battery_props[] = {
  74         POWER_SUPPLY_PROP_PRESENT,
  75         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  76         POWER_SUPPLY_PROP_CURRENT_NOW,
  77         POWER_SUPPLY_PROP_CHARGE_NOW,
  78         POWER_SUPPLY_PROP_CAPACITY,
  79         POWER_SUPPLY_PROP_TEMP,
  80 };
  81
  82 static int bq27x00_read(u8 reg, int *rt_value, int b_single,
  83         struct bq27x00_device_info *di);
  84
  85 #ifdef CONFIG_BATTERY_BQ27000
  86 static int bq27000_battery_probe(struct platform_device *dev);
  87 static int bq27000_battery_remove(struct platform_device *dev);
  88 #ifdef CONFIG_PM
  89 static int bq27000_battery_suspend(struct platform_device *dev,
  90         pm_message_t state);
  91 static int bq27000_battery_resume(struct platform_device *dev);
  92 #endif /* CONFIG_PM */
  93
  94 static struct platform_driver bq27000_battery_driver = {
  95         .probe = bq27000_battery_probe,
  96         .remove = bq27000_battery_remove,
  97 #ifdef CONFIG_PM
  98         .suspend = bq27000_battery_suspend,
  99         .resume = bq27000_battery_resume,
 100 #endif /* CONFIG_PM */
 101         .driver = {
 102                 .name = "bq27000-battery",
 103         },
 104 };
 105 #endif /* CONFIG_BATTERY_BQ27000 */
 106
 107 #ifdef CONFIG_BATTERY_BQ27200
 108 static int bq27200_battery_probe(struct i2c_client *client);
 109 static int bq27200_battery_remove(struct i2c_client *client);
 110 #ifdef CONFIG_PM
 111 static int bq27200_battery_suspend(struct i2c_client *client,
 112                 pm_message_t mesg);
 113 static int bq27200_battery_resume(struct i2c_client *client);
 114 #endif /* CONFIG_PM */
 115 static struct i2c_driver bq27200_battery_driver = {
 116         .driver = {
 117                 .name   = "bq27200-bat",
 118         },
 119         .probe  = bq27200_battery_probe,
 120         .remove = bq27200_battery_remove,
 121 #ifdef CONFIG_PM
 122         .suspend = bq27200_battery_suspend,
 123         .resume = bq27200_battery_resume,
 124 #endif /* CONFIG_PM */
 125 };
 126 #endif /* CONFIG_BATTERY_BQ27200 */
 127
 128 /*
 129  * Return the battery temperature in Celcius degrees
 130  * Or < 0 if something fails.
 131  */
 132 static int bq27x00_battery_temperature(struct bq27x00_device_info *di)
 133 {
 134         int ret, temp = 0;
 135
 136         ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di);
 137         if (ret) {
 138                 pr_err("BQ27x00 battery driver:"
 139                         "Error reading temperature from the battery\n");
 140                 return ret;
 141         }
 142
 143         return (temp >> 2) - 273;
 144 }
 145
 146 /*
 147  * Return the battery Voltage in milivolts
 148  * Or < 0 if something fails.
 149  */
 150 static int bq27x00_battery_voltage(struct bq27x00_device_info *di)
 151 {
 152         int ret, volt = 0;
 153
 154         ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di);
 155         if (ret) {
 156                 pr_err("BQ27x00 battery driver:"
 157                         "Error reading battery voltage from the battery\n");
 158                 return ret;
 159         }
 160
 161         return volt;
 162 }
 163
 164 /*
 165  * Return the battery average current
 166  * Note that current can be negative signed as well
 167  * Or 0 if something fails.
 168  */
 169 static int bq27x00_battery_current(struct bq27x00_device_info *di)
 170 {
 171         int ret, curr = 0, flags = 0;
 172
 173         ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di);
 174         if (ret) {
 175                 pr_err("BQ27x00 battery driver:"
 176                         "Error reading current from the battery\n");
 177                 return 0;
 178         }
 179         ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
 180         if (ret < 0) {
 181                 pr_err("BQ27x00 battery driver:"
 182                         "Error reading battery flags\n");
 183                 return 0;
 184         }
 185         if ((flags & (1 << 7)) != 0) {
 186                 pr_debug("Negative current\n");
 187                 return -curr;
 188         } else {
 189                 return curr;
 190         }
 191 }
 192
 193 /*
 194  * Return the battery Relative State-of-Charge
 195  * Or < 0 if something fails.
 196  */
 197 static int bq27x00_battery_rsoc(struct bq27x00_device_info *di)
 198 {
 199         int ret, rsoc = 0;
 200
 201         ret = bq27x00_read(BQ27x00_REG_RSOC, &rsoc, 1, di);
 202         if (ret) {
 203                 pr_err("BQ27x00 battery driver:"
 204                         "Error reading battery Relative"
 205                         "State-of-Charge\n");
 206                 return ret;
 207         }
 208         return rsoc;
 209 }
 210
 211 #ifdef CONFIG_BATTERY_BQ27000
 212 static inline int bq27000_read(u8 reg, int *rt_value, int b_single,
 213         struct bq27x00_device_info *di)
 214 {
 215         u8 val;
 216
 217         val = w1_bq27000_read(di->w1_dev, reg);
 218         *rt_value = val;
 219
 220         if (!b_single) {
 221                 val = 0;
 222                 val = w1_bq27000_read(di->w1_dev, reg + 1);
 223                 *rt_value +=  HIGH_BYTE((int) val);
 224         }
 225
 226         return 0;
 227 }
 228 #else
 229 static inline int bq27000_read(u8 reg, int *rt_value, int b_single,
 230         struct bq27x00_device_info *di)
 231 {
 232         return 0;
 233 }
 234 #endif
 235
 236 #ifdef CONFIG_BATTERY_BQ27200
 237 static inline int bq27200_read(u8 reg, int *rt_value, int b_single,
 238         struct bq27x00_device_info *di)
 239 {
 240         struct i2c_client *client = di->client;
 241         struct i2c_msg msg[1];
 242         unsigned char data[2];
 243         int err;
 244
 245         if (!client->adapter)
 246                 return -ENODEV;
 247
 248         msg->addr = client->addr;
 249         msg->flags = 0;
 250         msg->len = 1;
 251         msg->buf = data;
 252
 253         data[0] = reg;
 254         err = i2c_transfer(client->adapter, msg, 1);
 255
 256         if (err >= 0) {
 257                 if (!b_single)
 258                         msg->len = 2;
 259                 else
 260                         msg->len = 1;
 261
 262                 msg->flags = I2C_M_RD;
 263                 err = i2c_transfer(client->adapter, msg, 1);
 264                 if (err >= 0) {
 265                         if (!b_single)
 266                                 *rt_value = data[1] | HIGH_BYTE(data[0]);
 267                         else
 268                                 *rt_value = data[0];
 269
 270                         return 0;
 271                 } else {
 272                         pr_err("BQ27200 I2C read failed\n");
 273                         return err;
 274                 }
 275         } else {
 276                 pr_err("BQ27200 I2C write failed\n");
 277                 return err;
 278         }
 279 }
 280 #else
 281 static inline int bq27200_read(u8 reg, int *rt_value, int b_single,
 282         struct bq27x00_device_info *di)
 283 {
 284         return 0;
 285 }
 286 #endif
 287
 288 static int bq27x00_read(u8 reg, int *rt_value, int b_single,
 289         struct bq27x00_device_info *di)
 290 {
 291         int ret;
 292
 293         ret = di->bus->read(reg, rt_value, b_single, di);
 294         return ret;
 295 }
 296
 297 /*
 298  * Read the battery temp, voltage, current and relative state of charge.
 299  */
 300 static void bq27x00_battery_read_status(struct bq27x00_device_info *di)
 301 {
 302         if (di->update_time && time_before(jiffies, di->update_time +
 303                                         msecs_to_jiffies(cache_time)))
 304                 return;
 305
 306         di->temp_C = bq27x00_battery_temperature(di);
 307         di->voltage_uV = bq27x00_battery_voltage(di);
 308         di->current_uA = bq27x00_battery_current(di);
 309         di->charge_rsoc = bq27x00_battery_rsoc(di);
 310
 311         di->update_time = jiffies;
 312
 313         return;
 314 }
 315
 316 static void bq27x00_battery_work(struct delayed_work *work)
 317 {
 318         struct bq27x00_device_info *di = container_of(work,
 319                 struct bq27x00_device_info, monitor_work);
 320
 321         bq27x00_battery_read_status(di);
 322         schedule_delayed_work(&di->monitor_work, 100);
 323         return;
 324 }
 325
 326 #define to_bq27x00_device_info(x) container_of((x), \
 327                                 struct bq27x00_device_info, bat);
 328
 329 static int bq27x00_battery_get_property(struct power_supply *psy,
 330                                         enum power_supply_property psp,
 331                                         union power_supply_propval *val)
 332 {
 333         struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
 334
 335         switch (psp) {
 336         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 337                 val->intval = di->voltage_uV;
 338                 break;
 339         case POWER_SUPPLY_PROP_CURRENT_NOW:
 340                 val->intval = di->current_uA;
 341                 break;
 342         case POWER_SUPPLY_PROP_CHARGE_NOW:
 343                 val->intval = di->charge_rsoc;
 344                 break;
 345         case POWER_SUPPLY_PROP_TEMP:
 346                 val->intval = di->temp_C;
 347                 break;
 348         case POWER_SUPPLY_PROP_CAPACITY:
 349                 val->intval = di->charge_rsoc;
 350                 break;
 351         case POWER_SUPPLY_PROP_PRESENT:
 352                 if (di->voltage_uV == 0)
 353                         val->intval = 0;
 354                 else
 355                         val->intval = 1;
 356                 break;
 357         default:
 358                 return -EINVAL;
 359         }
 360
 361         return 0;
 362 }
 363
 364 static void bq27x00_powersupply_init(struct bq27x00_device_info *di)
 365 {
 366         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 367         di->bat.properties = bq27x00_battery_props;
 368         di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
 369         di->bat.get_property = bq27x00_battery_get_property;
 370         di->bat.external_power_changed = NULL;
 371         return;
 372 }
 373
 374 #ifdef CONFIG_BATTERY_BQ27200
 375 static int bq27200_battery_probe(struct i2c_client *client)
 376 {
 377         struct bq27x00_device_info *di;
 378         struct bq27x00_access_methods *bus;
 379         int retval = 0;
 380
 381         di = kzalloc(sizeof(*di), GFP_KERNEL);
 382         if (!di) {
 383                 pr_err("BQ27000 battery driver:"
 384                         "Failed to allocate device info structure\n");
 385                 return -ENOMEM;
 386         }
 387
 388         bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 389         if (!bus) {
 390                 pr_err("BQ27000 battery driver:"
 391                         "Failed to allocate access method structure\n");
 392                 kfree(di);
 393                 return -ENOMEM;
 394         }
 395
 396         i2c_set_clientdata(client, di);
 397         di->dev = &client->dev;
 398         di->bat.name = "bq27200";
 399         bus->read = &bq27200_read;
 400         di->bus = bus;
 401         di->client = client;
 402
 403         bq27x00_powersupply_init(di);
 404
 405         retval = power_supply_register(&client->dev, &di->bat);
 406         if (retval) {
 407                 pr_err("BQ27200 battery driver: Failed to register battery\n");
 408                 goto batt_failed;
 409         }
 410
 411         INIT_DELAYED_WORK(&di->monitor_work, bq27x00_battery_work);
 412         schedule_delayed_work(&di->monitor_work, 100);
 413
 414         return 0;
 415
 416 batt_failed:
 417         kfree(bus);
 418         kfree(di);
 419         return retval;
 420 }
 421
 422 static int bq27200_battery_remove(struct i2c_client *client)
 423 {
 424         struct bq27x00_device_info *di  = i2c_get_clientdata(client);
 425
 426         flush_scheduled_work();
 427         power_supply_unregister(&di->bat);
 428         kfree(di);
 429
 430         return 0;
 431 }
 432
 433 #ifdef CONFIG_PM
 434 static int bq27200_battery_suspend(struct i2c_client *client, pm_message_t mesg)
 435 {
 436         struct bq27x00_device_info *di  = i2c_get_clientdata(client);
 437
 438         cancel_delayed_work(&di->monitor_work);
 439         return 0;
 440 }
 441
 442 static int bq27200_battery_resume(struct i2c_client *client)
 443 {
 444         struct bq27x00_device_info *di  = i2c_get_clientdata(client);
 445
 446         schedule_delayed_work(&di->monitor_work, 0);
 447         return 0;
 448 }
 449 #endif /* CONFIG_PM */
 450 #endif /* CONFIG_BATTERY_BQ27200 */
 451
 452 #ifdef CONFIG_BATTERY_BQ27000
 453 static int bq27000_battery_probe(struct  platform_device *pdev)
 454 {
 455         struct bq27x00_device_info *di;
 456         struct bq27x00_access_methods *bus;
 457         int retval = 0;
 458
 459         di = kzalloc(sizeof(*di), GFP_KERNEL);
 460         if (!di) {
 461                 pr_err("BQ27000 battery driver:"
 462                         "Failed to allocate device info structure\n");
 463                 return -ENOMEM;
 464         }
 465
 466         bus = kzalloc(sizeof(*bus), GFP_KERNEL);
 467         if (!bus) {
 468                 pr_err("BQ27000 battery driver:"
 469                         "Failed to allocate access method structure\n");
 470                 kfree(di);
 471                 return -ENOMEM;
 472         }
 473
 474         platform_set_drvdata(pdev, di);
 475
 476         di->dev = &pdev->dev;
 477         di->w1_dev = pdev->dev.parent;
 478         di->bat.name = "bq27000";
 479         bus->read = &bq27000_read;
 480         di->bus = bus;
 481
 482         bq27x00_powersupply_init(di);
 483
 484         retval = power_supply_register(&pdev->dev, &di->bat);
 485         if (retval) {
 486                 pr_err("BQ27000 battery driver: Failed to register battery\n");
 487                 goto batt_failed;
 488         }
 489
 490         INIT_DELAYED_WORK(&di->monitor_work, bq27x00_battery_work);
 491         schedule_delayed_work(&di->monitor_work, 50);
 492
 493         return 0;
 494
 495 batt_failed:
 496         kfree(bus);
 497         kfree(di);
 498         return retval;
 499 }
 500
 501 static int bq27000_battery_remove(struct  platform_device *pdev)
 502 {
 503         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 504
 505         flush_scheduled_work();
 506         power_supply_unregister(&di->bat);
 507         platform_set_drvdata(pdev, NULL);
 508         kfree(di);
 509
 510         return 0;
 511 }
 512
 513 #ifdef CONFIG_PM
 514 static int bq27000_battery_suspend(struct platform_device *pdev,
 515         pm_message_t state)
 516 {
 517         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 518
 519         cancel_delayed_work(&di->monitor_work);
 520         return 0;
 521 }
 522
 523 static int bq27000_battery_resume(struct platform_device *pdev)
 524 {
 525         struct bq27x00_device_info *di = platform_get_drvdata(pdev);
 526
 527         schedule_delayed_work(&di->monitor_work, 0);
 528         return 0;
 529 }
 530 #endif /* CONFIG_PM */
 531 #endif /* CONFIG_BATTERY_BQ27000 */
 532
 533 static int __init bq27x00_battery_init(void)
 534 {
 535         int status = 0;
 536
 537 #ifdef CONFIG_BATTERY_BQ27000
 538         status = platform_driver_register(&bq27000_battery_driver);
 539         if (status)
 540                 printk(KERN_ERR "Unable to register BQ27000 driver\n");
 541 #endif
 542 #ifdef CONFIG_BATTERY_BQ27200
 543         status = i2c_add_driver(&bq27200_battery_driver);
 544                 printk(KERN_ERR "Unable to register BQ27200 driver\n");
 545 #endif
 546         return status;
 547 }
 548
 549 static void __exit bq27x00_battery_exit(void)
 550 {
 551 #ifdef CONFIG_BATTERY_BQ27000
 552         platform_driver_unregister(&bq27000_battery_driver);
 553 #endif
 554 #ifdef CONFIG_BATTERY_BQ27200
 555         i2c_del_driver(&bq27200_battery_driver);
 556 #endif
 557 }
 558
 559 module_init(bq27x00_battery_init);
 560 module_exit(bq27x00_battery_exit);
 561
 562 MODULE_AUTHOR("Texas Instruments");
 563 MODULE_DESCRIPTION("BQ27x00 battery moniter driver");
 564 MODULE_LICENSE("GPL");