drivers/power/bq27510_battery.c

   1 /*
   2  * BQ27510 battery driver
   3  *
   4  * This package is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
   9  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  10  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  */
  13 #include <linux/module.h>
  14 #include <linux/param.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/workqueue.h>
  17 #include <linux/delay.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/power_supply.h>
  20 #include <linux/idr.h>
  21 #include <linux/i2c.h>
  22 #include <linux/slab.h>
  23 #include <asm/unaligned.h>
  24
  25 #define DRIVER_VERSION                  "1.1.0"
  26
  27 #define BQ27x00_REG_TEMP                0x06
  28 #define BQ27x00_REG_VOLT                0x08
  29 #define BQ27x00_REG_AI                  0x14
  30 #define BQ27x00_REG_FLAGS               0x0A
  31 #define BQ27x00_REG_TTE                 0x16
  32 #define BQ27x00_REG_TTF                 0x18
  33 #define BQ27x00_REG_TTECP               0x26
  34
  35 #define BQ27000_REG_RSOC                0x0B /* Relative State-of-Charge */
  36 #define BQ27000_FLAG_CHGS               BIT(7)
  37
  38 #define BQ27500_REG_SOC                 0x2c
  39 #define BQ27500_FLAG_DSC                BIT(0)
  40 #define BQ27500_FLAG_FC                 BIT(9)
  41
  42 #define BQ27510_SPEED                   300 * 1000
  43
  44 #if 0
  45 #define DBG(x...) printk(KERN_INFO x)
  46 #else
  47 #define DBG(x...) do { } while (0)
  48 #endif
  49
  50 /* If the system has several batteries we need a different name for each
  51  * of them...
  52  */
  53 static DEFINE_MUTEX(battery_mutex);
  54
  55 struct bq27510_device_info {
  56         struct device           *dev;
  57         struct power_supply     bat;
  58         struct delayed_work work;
  59         unsigned int interval;
  60         struct i2c_client       *client;
  61 };
  62
  63 static enum power_supply_property bq27510_battery_props[] = {
  64         POWER_SUPPLY_PROP_STATUS,
  65         POWER_SUPPLY_PROP_PRESENT,
  66         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  67         POWER_SUPPLY_PROP_CURRENT_NOW,
  68         POWER_SUPPLY_PROP_CAPACITY,
  69         //POWER_SUPPLY_PROP_TEMP,
  70         //POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
  71         //POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
  72         //POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
  73 };
  74
  75 /*
  76  * Common code for BQ27510 devices read
  77  */
  78 static int bq27510_read(struct i2c_client *client, u8 reg, u8 buf[], unsigned len)
  79 {
  80         int ret;
  81         ret = i2c_master_reg8_recv(client, reg, buf, len, BQ27510_SPEED);
  82         return ret;
  83 }
  84
  85 /*
  86  * Return the battery temperature in tenths of degree Celsius
  87  * Or < 0 if something fails.
  88  */
  89 static int bq27510_battery_temperature(struct bq27510_device_info *di)
  90 {
  91         int ret;
  92         int temp = 0;
  93         u8 buf[2];
  94         ret = bq27510_read(di->client,BQ27x00_REG_TEMP,buf,2);
  95         if (ret<0) {
  96                 dev_err(di->dev, "error reading temperature\n");
  97                 return ret;
  98         }
  99         temp = get_unaligned_le16(buf);
 100         temp = temp - 2731;
 101         DBG("Enter:%s %d--temp = %d\n",__FUNCTION__,__LINE__,temp);
 102         return temp;
 103 }
 104
 105 /*
 106  * Return the battery Voltage in milivolts
 107  * Or < 0 if something fails.
 108  */
 109 static int bq27510_battery_voltage(struct bq27510_device_info *di)
 110 {
 111         int ret;
 112         u8 buf[2];
 113         int volt = 0;
 114
 115         ret = bq27510_read(di->client,BQ27x00_REG_VOLT,buf,2);
 116         if (ret<0) {
 117                 dev_err(di->dev, "error reading voltage\n");
 118                 return ret;
 119         }
 120         volt = get_unaligned_le16(buf);
 121         volt = volt * 1000;
 122         DBG("Enter:%s %d--volt = %d\n",__FUNCTION__,__LINE__,volt);
 123         return volt;
 124 }
 125
 126 /*
 127  * Return the battery average current
 128  * Note that current can be negative signed as well
 129  * Or 0 if something fails.
 130  */
 131 static int bq27510_battery_current(struct bq27510_device_info *di)
 132 {
 133         int ret;
 134         int curr = 0;
 135         u8 buf[2];
 136
 137         ret = bq27510_read(di->client,BQ27x00_REG_AI,buf,2);
 138         if (ret<0) {
 139                 dev_err(di->dev, "error reading current\n");
 140                 return 0;
 141         }
 142
 143         curr = get_unaligned_le16(buf);
 144         curr = curr * 1000;
 145         DBG("Enter:%s %d--curr = %d\n",__FUNCTION__,__LINE__,curr);
 146         return curr;
 147 }
 148
 149 /*
 150  * Return the battery Relative State-of-Charge
 151  * Or < 0 if something fails.
 152  */
 153 static int bq27510_battery_rsoc(struct bq27510_device_info *di)
 154 {
 155         int ret;
 156         int rsoc = 0;
 157         u8 buf[2];
 158
 159         ret = bq27510_read(di->client,BQ27500_REG_SOC,buf,2);
 160         if (ret<0) {
 161                 dev_err(di->dev, "error reading relative State-of-Charge\n");
 162                 return ret;
 163         }
 164         rsoc = get_unaligned_le16(buf);
 165         DBG("Enter:%s %d--rsoc = %d\n",__FUNCTION__,__LINE__,rsoc);
 166         return rsoc;
 167 }
 168
 169 static int bq27510_battery_status(struct bq27510_device_info *di,
 170                                   union power_supply_propval *val)
 171 {
 172         u8 buf[2];
 173         int flags = 0;
 174         int status;
 175         int ret;
 176
 177         ret = bq27510_read(di->client,BQ27x00_REG_FLAGS, buf, 2);
 178         if (ret < 0) {
 179                 dev_err(di->dev, "error reading flags\n");
 180                 return ret;
 181         }
 182         flags = get_unaligned_le16(buf);
 183         if (flags & BQ27500_FLAG_FC)
 184                 status = POWER_SUPPLY_STATUS_FULL;
 185         else if (flags & BQ27500_FLAG_DSC)
 186                 status = POWER_SUPPLY_STATUS_DISCHARGING;
 187         else
 188                 status = POWER_SUPPLY_STATUS_CHARGING;
 189
 190         val->intval = status;
 191         return 0;
 192 }
 193
 194 /*
 195  * Read a time register.
 196  * Return < 0 if something fails.
 197  */
 198 static int bq27510_battery_time(struct bq27510_device_info *di, int reg,
 199                                 union power_supply_propval *val)
 200 {
 201         u8 buf[2];
 202         int tval = 0;
 203         int ret;
 204
 205         ret = bq27510_read(di->client,reg,buf,2);
 206         if (ret<0) {
 207                 dev_err(di->dev, "error reading register %02x\n", reg);
 208                 return ret;
 209         }
 210         tval = get_unaligned_le16(buf);
 211         DBG("Enter:%s %d--no battery data\n",__FUNCTION__,__LINE__,val->intval);
 212         if (tval == 65535)
 213                 return -ENODATA;
 214
 215         val->intval = tval * 60;
 216         DBG("Enter:%s %d val->intval = %d\n",__FUNCTION__,__LINE__,val->intval);
 217         return 0;
 218 }
 219
 220 #define to_bq27510_device_info(x) container_of((x), \
 221                                 struct bq27510_device_info, bat);
 222
 223 static int bq27510_battery_get_property(struct power_supply *psy,
 224                                         enum power_supply_property psp,
 225                                         union power_supply_propval *val)
 226 {
 227         int ret = 0;
 228         struct bq27510_device_info *di = to_bq27510_device_info(psy);
 229
 230         switch (psp) {
 231         case POWER_SUPPLY_PROP_STATUS:
 232                 ret = bq27510_battery_status(di, val);
 233                 break;
 234         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 235         case POWER_SUPPLY_PROP_PRESENT:
 236                 val->intval = bq27510_battery_voltage(di);
 237                 if (psp == POWER_SUPPLY_PROP_PRESENT)
 238                         val->intval = val->intval <= 0 ? 0 : 1;
 239                 break;
 240         case POWER_SUPPLY_PROP_CURRENT_NOW:
 241                 val->intval = bq27510_battery_current(di);
 242                 break;
 243         case POWER_SUPPLY_PROP_CAPACITY:
 244                 val->intval = 100; ///bq27510_battery_rsoc(di);
 245                 break;
 246         case POWER_SUPPLY_PROP_TEMP:
 247                 val->intval = bq27510_battery_temperature(di);
 248                 break;
 249         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
 250                 ret = bq27510_battery_time(di, BQ27x00_REG_TTE, val);
 251                 break;
 252         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 253                 ret = bq27510_battery_time(di, BQ27x00_REG_TTECP, val);
 254                 break;
 255         case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
 256                 ret = bq27510_battery_time(di, BQ27x00_REG_TTF, val);
 257                 break;
 258         default:
 259                 return -EINVAL;
 260         }
 261
 262         return ret;
 263 }
 264
 265 static void bq27510_powersupply_init(struct bq27510_device_info *di)
 266 {
 267         di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 268         di->bat.properties = bq27510_battery_props;
 269         di->bat.num_properties = ARRAY_SIZE(bq27510_battery_props);
 270         di->bat.get_property = bq27510_battery_get_property;
 271         di->bat.external_power_changed = NULL;
 272 }
 273
 274 static void bq27510_battery_update_status(struct bq27510_device_info *di)
 275 {
 276         power_supply_changed(&di->bat);
 277 }
 278
 279 static void bq27510_battery_work(struct work_struct *work)
 280 {
 281         struct bq27510_device_info *di = container_of(work, struct bq27510_device_info, work.work);
 282         bq27510_battery_update_status(di);
 283         /* reschedule for the next time */
 284         schedule_delayed_work(&di->work, di->interval);
 285 }
 286
 287 static int bq27510_battery_probe(struct i2c_client *client,
 288                                  const struct i2c_device_id *id)
 289 {
 290         struct bq27510_device_info *di;
 291         int retval = 0;
 292
 293         di = kzalloc(sizeof(*di), GFP_KERNEL);
 294         if (!di) {
 295                 dev_err(&client->dev, "failed to allocate device info data\n");
 296                 retval = -ENOMEM;
 297                 goto batt_failed_2;
 298         }
 299         i2c_set_clientdata(client, di);
 300         di->dev = &client->dev;
 301         di->bat.name = "bq27510-battery";
 302         di->client = client;
 303         /* 4 seconds between monotor runs interval */
 304         di->interval = msecs_to_jiffies(4 * 1000);
 305         bq27510_powersupply_init(di);
 306
 307         retval = power_supply_register(&client->dev, &di->bat);
 308         if (retval) {
 309                 dev_err(&client->dev, "failed to register battery\n");
 310                 goto batt_failed_4;
 311         }
 312         INIT_DELAYED_WORK(&di->work, bq27510_battery_work);
 313         schedule_delayed_work(&di->work, di->interval);
 314         dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
 315
 316         return 0;
 317
 318 batt_failed_4:
 319         kfree(di);
 320 batt_failed_2:
 321         return retval;
 322 }
 323
 324 static int bq27510_battery_remove(struct i2c_client *client)
 325 {
 326         struct bq27510_device_info *di = i2c_get_clientdata(client);
 327
 328         power_supply_unregister(&di->bat);
 329         kfree(di->bat.name);
 330         kfree(di);
 331         return 0;
 332 }
 333
 334 /*
 335  * Module stuff
 336  */
 337
 338 static const struct i2c_device_id bq27510_id[] = {
 339         { "bq27510", 0 },
 340 };
 341
 342 static struct i2c_driver bq27510_battery_driver = {
 343         .driver = {
 344                 .name = "bq27510-battery",
 345         },
 346         .probe = bq27510_battery_probe,
 347         .remove = bq27510_battery_remove,
 348         .id_table = bq27510_id,
 349 };
 350
 351 static int __init bq27510_battery_init(void)
 352 {
 353         int ret;
 354
 355         ret = i2c_add_driver(&bq27510_battery_driver);
 356         if (ret)
 357                 printk(KERN_ERR "Unable to register BQ27510 driver\n");
 358         return ret;
 359 }
 360 module_init(bq27510_battery_init);
 361
 362 static void __exit bq27510_battery_exit(void)
 363 {
 364         i2c_del_driver(&bq27510_battery_driver);
 365 }
 366 module_exit(bq27510_battery_exit);
 367
 368 MODULE_AUTHOR("Rockchip");
 369 MODULE_DESCRIPTION("BQ27510 battery monitor driver");
 370 MODULE_LICENSE("GPL");