drivers/power/supply/bq24735-charger.c

   1 /*
   2  * Battery charger driver for TI BQ24735
   3  *
   4  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation;
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  */
  19
  20 #include <linux/devm-helpers.h>
  21 #include <linux/err.h>
  22 #include <linux/i2c.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/of.h>
  28 #include <linux/gpio/consumer.h>
  29 #include <linux/power_supply.h>
  30 #include <linux/slab.h>
  31
  32 #include <linux/power/bq24735-charger.h>
  33
  34 /* BQ24735 available commands and their respective masks */
  35 #define BQ24735_CHARGE_OPT              0x12
  36 #define BQ24735_CHARGE_CURRENT          0x14
  37 #define BQ24735_CHARGE_CURRENT_MASK     0x1fc0
  38 #define BQ24735_CHARGE_VOLTAGE          0x15
  39 #define BQ24735_CHARGE_VOLTAGE_MASK     0x7ff0
  40 #define BQ24735_INPUT_CURRENT           0x3f
  41 #define BQ24735_INPUT_CURRENT_MASK      0x1f80
  42 #define BQ24735_MANUFACTURER_ID         0xfe
  43 #define BQ24735_DEVICE_ID               0xff
  44
  45 /* ChargeOptions bits of interest */
  46 #define BQ24735_CHARGE_OPT_CHG_DISABLE  (1 << 0)
  47 #define BQ24735_CHARGE_OPT_AC_PRESENT   (1 << 4)
  48
  49 struct bq24735 {
  50         struct power_supply             *charger;
  51         struct power_supply_desc        charger_desc;
  52         struct i2c_client               *client;
  53         struct bq24735_platform         *pdata;
  54         struct mutex                    lock;
  55         struct gpio_desc                *status_gpio;
  56         struct delayed_work             poll;
  57         u32                             poll_interval;
  58         bool                            charging;
  59 };
  60
  61 static inline struct bq24735 *to_bq24735(struct power_supply *psy)
  62 {
  63         return power_supply_get_drvdata(psy);
  64 }
  65
  66 static enum power_supply_property bq24735_charger_properties[] = {
  67         POWER_SUPPLY_PROP_STATUS,
  68         POWER_SUPPLY_PROP_ONLINE,
  69 };
  70
  71 static int bq24735_charger_property_is_writeable(struct power_supply *psy,
  72                                                  enum power_supply_property psp)
  73 {
  74         switch (psp) {
  75         case POWER_SUPPLY_PROP_STATUS:
  76                 return 1;
  77         default:
  78                 break;
  79         }
  80
  81         return 0;
  82 }
  83
  84 static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
  85                                      u16 value)
  86 {
  87         return i2c_smbus_write_word_data(client, reg, value);
  88 }
  89
  90 static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
  91 {
  92         return i2c_smbus_read_word_data(client, reg);
  93 }
  94
  95 static int bq24735_update_word(struct i2c_client *client, u8 reg,
  96                                u16 mask, u16 value)
  97 {
  98         unsigned int tmp;
  99         int ret;
 100
 101         ret = bq24735_read_word(client, reg);
 102         if (ret < 0)
 103                 return ret;
 104
 105         tmp = ret & ~mask;
 106         tmp |= value & mask;
 107
 108         return bq24735_write_word(client, reg, tmp);
 109 }
 110
 111 static int bq24735_config_charger(struct bq24735 *charger)
 112 {
 113         struct bq24735_platform *pdata = charger->pdata;
 114         int ret;
 115         u16 value;
 116
 117         if (pdata->ext_control)
 118                 return 0;
 119
 120         if (pdata->charge_current) {
 121                 value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
 122
 123                 ret = bq24735_write_word(charger->client,
 124                                          BQ24735_CHARGE_CURRENT, value);
 125                 if (ret < 0) {
 126                         dev_err(&charger->client->dev,
 127                                 "Failed to write charger current : %d\n",
 128                                 ret);
 129                         return ret;
 130                 }
 131         }
 132
 133         if (pdata->charge_voltage) {
 134                 value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
 135
 136                 ret = bq24735_write_word(charger->client,
 137                                          BQ24735_CHARGE_VOLTAGE, value);
 138                 if (ret < 0) {
 139                         dev_err(&charger->client->dev,
 140                                 "Failed to write charger voltage : %d\n",
 141                                 ret);
 142                         return ret;
 143                 }
 144         }
 145
 146         if (pdata->input_current) {
 147                 value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
 148
 149                 ret = bq24735_write_word(charger->client,
 150                                          BQ24735_INPUT_CURRENT, value);
 151                 if (ret < 0) {
 152                         dev_err(&charger->client->dev,
 153                                 "Failed to write input current : %d\n",
 154                                 ret);
 155                         return ret;
 156                 }
 157         }
 158
 159         return 0;
 160 }
 161
 162 static inline int bq24735_enable_charging(struct bq24735 *charger)
 163 {
 164         int ret;
 165
 166         if (charger->pdata->ext_control)
 167                 return 0;
 168
 169         ret = bq24735_config_charger(charger);
 170         if (ret)
 171                 return ret;
 172
 173         return bq24735_update_word(charger->client, BQ24735_CHARGE_OPT,
 174                                    BQ24735_CHARGE_OPT_CHG_DISABLE, 0);
 175 }
 176
 177 static inline int bq24735_disable_charging(struct bq24735 *charger)
 178 {
 179         if (charger->pdata->ext_control)
 180                 return 0;
 181
 182         return bq24735_update_word(charger->client, BQ24735_CHARGE_OPT,
 183                                    BQ24735_CHARGE_OPT_CHG_DISABLE,
 184                                    BQ24735_CHARGE_OPT_CHG_DISABLE);
 185 }
 186
 187 static bool bq24735_charger_is_present(struct bq24735 *charger)
 188 {
 189         if (charger->status_gpio) {
 190                 return !gpiod_get_value_cansleep(charger->status_gpio);
 191         } else {
 192                 int ac = 0;
 193
 194                 ac = bq24735_read_word(charger->client, BQ24735_CHARGE_OPT);
 195                 if (ac < 0) {
 196                         dev_dbg(&charger->client->dev,
 197                                 "Failed to read charger options : %d\n",
 198                                 ac);
 199                         return false;
 200                 }
 201                 return (ac & BQ24735_CHARGE_OPT_AC_PRESENT) ? true : false;
 202         }
 203
 204         return false;
 205 }
 206
 207 static int bq24735_charger_is_charging(struct bq24735 *charger)
 208 {
 209         int ret;
 210
 211         if (!bq24735_charger_is_present(charger))
 212                 return 0;
 213
 214         ret  = bq24735_read_word(charger->client, BQ24735_CHARGE_OPT);
 215         if (ret < 0)
 216                 return ret;
 217
 218         return !(ret & BQ24735_CHARGE_OPT_CHG_DISABLE);
 219 }
 220
 221 static void bq24735_update(struct bq24735 *charger)
 222 {
 223         mutex_lock(&charger->lock);
 224
 225         if (charger->charging && bq24735_charger_is_present(charger))
 226                 bq24735_enable_charging(charger);
 227         else
 228                 bq24735_disable_charging(charger);
 229
 230         mutex_unlock(&charger->lock);
 231
 232         power_supply_changed(charger->charger);
 233 }
 234
 235 static irqreturn_t bq24735_charger_isr(int irq, void *devid)
 236 {
 237         struct power_supply *psy = devid;
 238         struct bq24735 *charger = to_bq24735(psy);
 239
 240         bq24735_update(charger);
 241
 242         return IRQ_HANDLED;
 243 }
 244
 245 static void bq24735_poll(struct work_struct *work)
 246 {
 247         struct bq24735 *charger = container_of(work, struct bq24735, poll.work);
 248
 249         bq24735_update(charger);
 250
 251         schedule_delayed_work(&charger->poll,
 252                               msecs_to_jiffies(charger->poll_interval));
 253 }
 254
 255 static int bq24735_charger_get_property(struct power_supply *psy,
 256                                         enum power_supply_property psp,
 257                                         union power_supply_propval *val)
 258 {
 259         struct bq24735 *charger = to_bq24735(psy);
 260
 261         switch (psp) {
 262         case POWER_SUPPLY_PROP_ONLINE:
 263                 val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
 264                 break;
 265         case POWER_SUPPLY_PROP_STATUS:
 266                 switch (bq24735_charger_is_charging(charger)) {
 267                 case 1:
 268                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 269                         break;
 270                 case 0:
 271                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 272                         break;
 273                 default:
 274                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 275                         break;
 276                 }
 277                 break;
 278         default:
 279                 return -EINVAL;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static int bq24735_charger_set_property(struct power_supply *psy,
 286                                         enum power_supply_property psp,
 287                                         const union power_supply_propval *val)
 288 {
 289         struct bq24735 *charger = to_bq24735(psy);
 290         int ret;
 291
 292         switch (psp) {
 293         case POWER_SUPPLY_PROP_STATUS:
 294                 switch (val->intval) {
 295                 case POWER_SUPPLY_STATUS_CHARGING:
 296                         mutex_lock(&charger->lock);
 297                         charger->charging = true;
 298                         ret = bq24735_enable_charging(charger);
 299                         mutex_unlock(&charger->lock);
 300                         if (ret)
 301                                 return ret;
 302                         break;
 303                 case POWER_SUPPLY_STATUS_DISCHARGING:
 304                 case POWER_SUPPLY_STATUS_NOT_CHARGING:
 305                         mutex_lock(&charger->lock);
 306                         charger->charging = false;
 307                         ret = bq24735_disable_charging(charger);
 308                         mutex_unlock(&charger->lock);
 309                         if (ret)
 310                                 return ret;
 311                         break;
 312                 default:
 313                         return -EINVAL;
 314                 }
 315                 power_supply_changed(psy);
 316                 break;
 317         default:
 318                 return -EPERM;
 319         }
 320
 321         return 0;
 322 }
 323
 324 static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 325 {
 326         struct bq24735_platform *pdata;
 327         struct device_node *np = client->dev.of_node;
 328         u32 val;
 329         int ret;
 330
 331         pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 332         if (!pdata) {
 333                 dev_err(&client->dev,
 334                         "Memory alloc for bq24735 pdata failed\n");
 335                 return NULL;
 336         }
 337
 338         ret = of_property_read_u32(np, "ti,charge-current", &val);
 339         if (!ret)
 340                 pdata->charge_current = val;
 341
 342         ret = of_property_read_u32(np, "ti,charge-voltage", &val);
 343         if (!ret)
 344                 pdata->charge_voltage = val;
 345
 346         ret = of_property_read_u32(np, "ti,input-current", &val);
 347         if (!ret)
 348                 pdata->input_current = val;
 349
 350         pdata->ext_control = of_property_read_bool(np, "ti,external-control");
 351
 352         return pdata;
 353 }
 354
 355 static int bq24735_charger_probe(struct i2c_client *client)
 356 {
 357         int ret;
 358         struct bq24735 *charger;
 359         struct power_supply_desc *supply_desc;
 360         struct power_supply_config psy_cfg = {};
 361         char *name;
 362
 363         charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
 364         if (!charger)
 365                 return -ENOMEM;
 366
 367         mutex_init(&charger->lock);
 368         charger->charging = true;
 369         charger->pdata = client->dev.platform_data;
 370
 371         if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
 372                 charger->pdata = bq24735_parse_dt_data(client);
 373
 374         if (!charger->pdata) {
 375                 dev_err(&client->dev, "no platform data provided\n");
 376                 return -EINVAL;
 377         }
 378
 379         name = (char *)charger->pdata->name;
 380         if (!name) {
 381                 name = devm_kasprintf(&client->dev, GFP_KERNEL,
 382                                       "bq24735@%s",
 383                                       dev_name(&client->dev));
 384                 if (!name) {
 385                         dev_err(&client->dev, "Failed to alloc device name\n");
 386                         return -ENOMEM;
 387                 }
 388         }
 389
 390         charger->client = client;
 391
 392         supply_desc = &charger->charger_desc;
 393
 394         supply_desc->name = name;
 395         supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
 396         supply_desc->properties = bq24735_charger_properties;
 397         supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
 398         supply_desc->get_property = bq24735_charger_get_property;
 399         supply_desc->set_property = bq24735_charger_set_property;
 400         supply_desc->property_is_writeable =
 401                                 bq24735_charger_property_is_writeable;
 402
 403         psy_cfg.supplied_to = charger->pdata->supplied_to;
 404         psy_cfg.num_supplicants = charger->pdata->num_supplicants;
 405         psy_cfg.of_node = client->dev.of_node;
 406         psy_cfg.drv_data = charger;
 407
 408         i2c_set_clientdata(client, charger);
 409
 410         charger->status_gpio = devm_gpiod_get_optional(&client->dev,
 411                                                        "ti,ac-detect",
 412                                                        GPIOD_IN);
 413         if (IS_ERR(charger->status_gpio)) {
 414                 ret = PTR_ERR(charger->status_gpio);
 415                 dev_err(&client->dev, "Getting gpio failed: %d\n", ret);
 416                 return ret;
 417         }
 418
 419         if (bq24735_charger_is_present(charger)) {
 420                 ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
 421                 if (ret < 0) {
 422                         dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
 423                                 ret);
 424                         return ret;
 425                 } else if (ret != 0x0040) {
 426                         dev_err(&client->dev,
 427                                 "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
 428                         return -ENODEV;
 429                 }
 430
 431                 ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
 432                 if (ret < 0) {
 433                         dev_err(&client->dev, "Failed to read device id : %d\n", ret);
 434                         return ret;
 435                 } else if (ret != 0x000B) {
 436                         dev_err(&client->dev,
 437                                 "device id mismatch. 0x000b != 0x%04x\n", ret);
 438                         return -ENODEV;
 439                 }
 440
 441                 ret = bq24735_enable_charging(charger);
 442                 if (ret < 0) {
 443                         dev_err(&client->dev, "Failed to enable charging\n");
 444                         return ret;
 445                 }
 446         }
 447
 448         charger->charger = devm_power_supply_register(&client->dev, supply_desc,
 449                                                       &psy_cfg);
 450         if (IS_ERR(charger->charger)) {
 451                 ret = PTR_ERR(charger->charger);
 452                 dev_err(&client->dev, "Failed to register power supply: %d\n",
 453                         ret);
 454                 return ret;
 455         }
 456
 457         if (client->irq) {
 458                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 459                                                 NULL, bq24735_charger_isr,
 460                                                 IRQF_TRIGGER_RISING |
 461                                                 IRQF_TRIGGER_FALLING |
 462                                                 IRQF_ONESHOT,
 463                                                 supply_desc->name,
 464                                                 charger->charger);
 465                 if (ret) {
 466                         dev_err(&client->dev,
 467                                 "Unable to register IRQ %d err %d\n",
 468                                 client->irq, ret);
 469                         return ret;
 470                 }
 471         } else {
 472                 ret = device_property_read_u32(&client->dev, "poll-interval",
 473                                                &charger->poll_interval);
 474                 if (ret)
 475                         return 0;
 476                 if (!charger->poll_interval)
 477                         return 0;
 478
 479                 ret = devm_delayed_work_autocancel(&client->dev, &charger->poll,
 480                                                    bq24735_poll);
 481                 if (ret)
 482                         return ret;
 483
 484                 schedule_delayed_work(&charger->poll,
 485                                       msecs_to_jiffies(charger->poll_interval));
 486         }
 487
 488         return 0;
 489 }
 490
 491 static const struct i2c_device_id bq24735_charger_id[] = {
 492         { "bq24735-charger", 0 },
 493         {}
 494 };
 495 MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
 496
 497 static const struct of_device_id bq24735_match_ids[] = {
 498         { .compatible = "ti,bq24735", },
 499         { /* end */ }
 500 };
 501 MODULE_DEVICE_TABLE(of, bq24735_match_ids);
 502
 503 static struct i2c_driver bq24735_charger_driver = {
 504         .driver = {
 505                 .name = "bq24735-charger",
 506                 .of_match_table = bq24735_match_ids,
 507         },
 508         .probe = bq24735_charger_probe,
 509         .id_table = bq24735_charger_id,
 510 };
 511
 512 module_i2c_driver(bq24735_charger_driver);
 513
 514 MODULE_DESCRIPTION("bq24735 battery charging driver");
 515 MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
 516 MODULE_LICENSE("GPL v2");