drivers/power/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/err.h>
  21 #include <linux/gpio.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/of_gpio.h>
  29 #include <linux/power_supply.h>
  30 #include <linux/slab.h>
  31
  32 #include <linux/power/bq24735-charger.h>
  33
  34 #define BQ24735_CHG_OPT                 0x12
  35 #define BQ24735_CHG_OPT_CHARGE_DISABLE  (1 << 0)
  36 #define BQ24735_CHG_OPT_AC_PRESENT      (1 << 4)
  37 #define BQ24735_CHARGE_CURRENT          0x14
  38 #define BQ24735_CHARGE_CURRENT_MASK     0x1fc0
  39 #define BQ24735_CHARGE_VOLTAGE          0x15
  40 #define BQ24735_CHARGE_VOLTAGE_MASK     0x7ff0
  41 #define BQ24735_INPUT_CURRENT           0x3f
  42 #define BQ24735_INPUT_CURRENT_MASK      0x1f80
  43 #define BQ24735_MANUFACTURER_ID         0xfe
  44 #define BQ24735_DEVICE_ID               0xff
  45
  46 struct bq24735 {
  47         struct power_supply             *charger;
  48         struct power_supply_desc        charger_desc;
  49         struct i2c_client               *client;
  50         struct bq24735_platform         *pdata;
  51         struct mutex                    lock;
  52         bool                            charging;
  53 };
  54
  55 static inline struct bq24735 *to_bq24735(struct power_supply *psy)
  56 {
  57         return power_supply_get_drvdata(psy);
  58 }
  59
  60 static enum power_supply_property bq24735_charger_properties[] = {
  61         POWER_SUPPLY_PROP_STATUS,
  62         POWER_SUPPLY_PROP_ONLINE,
  63 };
  64
  65 static int bq24735_charger_property_is_writeable(struct power_supply *psy,
  66                                                  enum power_supply_property psp)
  67 {
  68         switch (psp) {
  69         case POWER_SUPPLY_PROP_STATUS:
  70                 return 1;
  71         default:
  72                 break;
  73         }
  74
  75         return 0;
  76 }
  77
  78 static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
  79                                      u16 value)
  80 {
  81         return i2c_smbus_write_word_data(client, reg, le16_to_cpu(value));
  82 }
  83
  84 static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
  85 {
  86         s32 ret = i2c_smbus_read_word_data(client, reg);
  87
  88         return ret < 0 ? ret : le16_to_cpu(ret);
  89 }
  90
  91 static int bq24735_update_word(struct i2c_client *client, u8 reg,
  92                                u16 mask, u16 value)
  93 {
  94         unsigned int tmp;
  95         int ret;
  96
  97         ret = bq24735_read_word(client, reg);
  98         if (ret < 0)
  99                 return ret;
 100
 101         tmp = ret & ~mask;
 102         tmp |= value & mask;
 103
 104         return bq24735_write_word(client, reg, tmp);
 105 }
 106
 107 static inline int bq24735_enable_charging(struct bq24735 *charger)
 108 {
 109         if (charger->pdata->ext_control)
 110                 return 0;
 111
 112         return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
 113                                    BQ24735_CHG_OPT_CHARGE_DISABLE,
 114                                    ~BQ24735_CHG_OPT_CHARGE_DISABLE);
 115 }
 116
 117 static inline int bq24735_disable_charging(struct bq24735 *charger)
 118 {
 119         if (charger->pdata->ext_control)
 120                 return 0;
 121
 122         return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
 123                                    BQ24735_CHG_OPT_CHARGE_DISABLE,
 124                                    BQ24735_CHG_OPT_CHARGE_DISABLE);
 125 }
 126
 127 static int bq24735_config_charger(struct bq24735 *charger)
 128 {
 129         struct bq24735_platform *pdata = charger->pdata;
 130         int ret;
 131         u16 value;
 132
 133         if (pdata->ext_control)
 134                 return 0;
 135
 136         if (pdata->charge_current) {
 137                 value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
 138
 139                 ret = bq24735_write_word(charger->client,
 140                                          BQ24735_CHARGE_CURRENT, value);
 141                 if (ret < 0) {
 142                         dev_err(&charger->client->dev,
 143                                 "Failed to write charger current : %d\n",
 144                                 ret);
 145                         return ret;
 146                 }
 147         }
 148
 149         if (pdata->charge_voltage) {
 150                 value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
 151
 152                 ret = bq24735_write_word(charger->client,
 153                                          BQ24735_CHARGE_VOLTAGE, value);
 154                 if (ret < 0) {
 155                         dev_err(&charger->client->dev,
 156                                 "Failed to write charger voltage : %d\n",
 157                                 ret);
 158                         return ret;
 159                 }
 160         }
 161
 162         if (pdata->input_current) {
 163                 value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
 164
 165                 ret = bq24735_write_word(charger->client,
 166                                          BQ24735_INPUT_CURRENT, value);
 167                 if (ret < 0) {
 168                         dev_err(&charger->client->dev,
 169                                 "Failed to write input current : %d\n",
 170                                 ret);
 171                         return ret;
 172                 }
 173         }
 174
 175         return 0;
 176 }
 177
 178 static bool bq24735_charger_is_present(struct bq24735 *charger)
 179 {
 180         struct bq24735_platform *pdata = charger->pdata;
 181         int ret;
 182
 183         if (pdata->status_gpio_valid) {
 184                 ret = gpio_get_value_cansleep(pdata->status_gpio);
 185                 return ret ^= pdata->status_gpio_active_low == 0;
 186         } else {
 187                 int ac = 0;
 188
 189                 ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
 190                 if (ac < 0) {
 191                         dev_err(&charger->client->dev,
 192                                 "Failed to read charger options : %d\n",
 193                                 ac);
 194                         return false;
 195                 }
 196                 return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false;
 197         }
 198
 199         return false;
 200 }
 201
 202 static int bq24735_charger_is_charging(struct bq24735 *charger)
 203 {
 204         int ret = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
 205
 206         if (ret < 0)
 207                 return ret;
 208
 209         return !(ret & BQ24735_CHG_OPT_CHARGE_DISABLE);
 210 }
 211
 212 static irqreturn_t bq24735_charger_isr(int irq, void *devid)
 213 {
 214         struct power_supply *psy = devid;
 215         struct bq24735 *charger = to_bq24735(psy);
 216
 217         mutex_lock(&charger->lock);
 218
 219         if (charger->charging && bq24735_charger_is_present(charger))
 220                 bq24735_enable_charging(charger);
 221         else
 222                 bq24735_disable_charging(charger);
 223
 224         mutex_unlock(&charger->lock);
 225
 226         power_supply_changed(psy);
 227
 228         return IRQ_HANDLED;
 229 }
 230
 231 static int bq24735_charger_get_property(struct power_supply *psy,
 232                                         enum power_supply_property psp,
 233                                         union power_supply_propval *val)
 234 {
 235         struct bq24735 *charger = to_bq24735(psy);
 236
 237         switch (psp) {
 238         case POWER_SUPPLY_PROP_ONLINE:
 239                 val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
 240                 break;
 241         case POWER_SUPPLY_PROP_STATUS:
 242                 switch (bq24735_charger_is_charging(charger)) {
 243                 case 1:
 244                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 245                         break;
 246                 case 0:
 247                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 248                         break;
 249                 default:
 250                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 251                         break;
 252                 }
 253                 break;
 254         default:
 255                 return -EINVAL;
 256         }
 257
 258         return 0;
 259 }
 260
 261 static int bq24735_charger_set_property(struct power_supply *psy,
 262                                         enum power_supply_property psp,
 263                                         const union power_supply_propval *val)
 264 {
 265         struct bq24735 *charger = to_bq24735(psy);
 266         int ret;
 267
 268         switch (psp) {
 269         case POWER_SUPPLY_PROP_STATUS:
 270                 switch (val->intval) {
 271                 case POWER_SUPPLY_STATUS_CHARGING:
 272                         mutex_lock(&charger->lock);
 273                         charger->charging = true;
 274                         ret = bq24735_enable_charging(charger);
 275                         mutex_unlock(&charger->lock);
 276                         if (ret)
 277                                 return ret;
 278                         bq24735_config_charger(charger);
 279                         break;
 280                 case POWER_SUPPLY_STATUS_DISCHARGING:
 281                 case POWER_SUPPLY_STATUS_NOT_CHARGING:
 282                         mutex_lock(&charger->lock);
 283                         charger->charging = false;
 284                         ret = bq24735_disable_charging(charger);
 285                         mutex_unlock(&charger->lock);
 286                         if (ret)
 287                                 return ret;
 288                         break;
 289                 default:
 290                         return -EINVAL;
 291                 }
 292                 power_supply_changed(psy);
 293                 break;
 294         default:
 295                 return -EPERM;
 296         }
 297
 298         return 0;
 299 }
 300
 301 static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 302 {
 303         struct bq24735_platform *pdata;
 304         struct device_node *np = client->dev.of_node;
 305         u32 val;
 306         int ret;
 307         enum of_gpio_flags flags;
 308
 309         pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 310         if (!pdata) {
 311                 dev_err(&client->dev,
 312                         "Memory alloc for bq24735 pdata failed\n");
 313                 return NULL;
 314         }
 315
 316         pdata->status_gpio = of_get_named_gpio_flags(np, "ti,ac-detect-gpios",
 317                                                      0, &flags);
 318
 319         if (flags & OF_GPIO_ACTIVE_LOW)
 320                 pdata->status_gpio_active_low = 1;
 321
 322         ret = of_property_read_u32(np, "ti,charge-current", &val);
 323         if (!ret)
 324                 pdata->charge_current = val;
 325
 326         ret = of_property_read_u32(np, "ti,charge-voltage", &val);
 327         if (!ret)
 328                 pdata->charge_voltage = val;
 329
 330         ret = of_property_read_u32(np, "ti,input-current", &val);
 331         if (!ret)
 332                 pdata->input_current = val;
 333
 334         pdata->ext_control = of_property_read_bool(np, "ti,external-control");
 335
 336         return pdata;
 337 }
 338
 339 static int bq24735_charger_probe(struct i2c_client *client,
 340                                  const struct i2c_device_id *id)
 341 {
 342         int ret;
 343         struct bq24735 *charger;
 344         struct power_supply_desc *supply_desc;
 345         struct power_supply_config psy_cfg = {};
 346         char *name;
 347
 348         charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
 349         if (!charger)
 350                 return -ENOMEM;
 351
 352         mutex_init(&charger->lock);
 353         charger->charging = true;
 354         charger->pdata = client->dev.platform_data;
 355
 356         if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
 357                 charger->pdata = bq24735_parse_dt_data(client);
 358
 359         if (!charger->pdata) {
 360                 dev_err(&client->dev, "no platform data provided\n");
 361                 return -EINVAL;
 362         }
 363
 364         name = (char *)charger->pdata->name;
 365         if (!name) {
 366                 name = devm_kasprintf(&client->dev, GFP_KERNEL,
 367                                       "bq24735@%s",
 368                                       dev_name(&client->dev));
 369                 if (!name) {
 370                         dev_err(&client->dev, "Failed to alloc device name\n");
 371                         return -ENOMEM;
 372                 }
 373         }
 374
 375         charger->client = client;
 376
 377         supply_desc = &charger->charger_desc;
 378
 379         supply_desc->name = name;
 380         supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
 381         supply_desc->properties = bq24735_charger_properties;
 382         supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
 383         supply_desc->get_property = bq24735_charger_get_property;
 384         supply_desc->set_property = bq24735_charger_set_property;
 385         supply_desc->property_is_writeable =
 386                                 bq24735_charger_property_is_writeable;
 387
 388         psy_cfg.supplied_to = charger->pdata->supplied_to;
 389         psy_cfg.num_supplicants = charger->pdata->num_supplicants;
 390         psy_cfg.of_node = client->dev.of_node;
 391         psy_cfg.drv_data = charger;
 392
 393         i2c_set_clientdata(client, charger);
 394
 395         if (gpio_is_valid(charger->pdata->status_gpio)) {
 396                 ret = devm_gpio_request(&client->dev,
 397                                         charger->pdata->status_gpio,
 398                                         name);
 399                 if (ret) {
 400                         dev_err(&client->dev,
 401                                 "Failed GPIO request for GPIO %d: %d\n",
 402                                 charger->pdata->status_gpio, ret);
 403                 }
 404
 405                 charger->pdata->status_gpio_valid = !ret;
 406         }
 407
 408         if (!charger->pdata->status_gpio_valid
 409             || bq24735_charger_is_present(charger)) {
 410                 ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
 411                 if (ret < 0) {
 412                         dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
 413                                 ret);
 414                         return ret;
 415                 } else if (ret != 0x0040) {
 416                         dev_err(&client->dev,
 417                                 "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
 418                         return -ENODEV;
 419                 }
 420
 421                 ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
 422                 if (ret < 0) {
 423                         dev_err(&client->dev, "Failed to read device id : %d\n", ret);
 424                         return ret;
 425                 } else if (ret != 0x000B) {
 426                         dev_err(&client->dev,
 427                                 "device id mismatch. 0x000b != 0x%04x\n", ret);
 428                         return -ENODEV;
 429                 }
 430         }
 431
 432         ret = bq24735_config_charger(charger);
 433         if (ret < 0) {
 434                 dev_err(&client->dev, "failed in configuring charger");
 435                 return ret;
 436         }
 437
 438         /* check for AC adapter presence */
 439         if (bq24735_charger_is_present(charger)) {
 440                 ret = bq24735_enable_charging(charger);
 441                 if (ret < 0) {
 442                         dev_err(&client->dev, "Failed to enable charging\n");
 443                         return ret;
 444                 }
 445         }
 446
 447         charger->charger = devm_power_supply_register(&client->dev, supply_desc,
 448                                                       &psy_cfg);
 449         if (IS_ERR(charger->charger)) {
 450                 ret = PTR_ERR(charger->charger);
 451                 dev_err(&client->dev, "Failed to register power supply: %d\n",
 452                         ret);
 453                 return ret;
 454         }
 455
 456         if (client->irq) {
 457                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 458                                                 NULL, bq24735_charger_isr,
 459                                                 IRQF_TRIGGER_RISING |
 460                                                 IRQF_TRIGGER_FALLING |
 461                                                 IRQF_ONESHOT,
 462                                                 supply_desc->name,
 463                                                 charger->charger);
 464                 if (ret) {
 465                         dev_err(&client->dev,
 466                                 "Unable to register IRQ %d err %d\n",
 467                                 client->irq, ret);
 468                         return ret;
 469                 }
 470         }
 471
 472         return 0;
 473 }
 474
 475 static const struct i2c_device_id bq24735_charger_id[] = {
 476         { "bq24735-charger", 0 },
 477         {}
 478 };
 479 MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
 480
 481 static const struct of_device_id bq24735_match_ids[] = {
 482         { .compatible = "ti,bq24735", },
 483         { /* end */ }
 484 };
 485 MODULE_DEVICE_TABLE(of, bq24735_match_ids);
 486
 487 static struct i2c_driver bq24735_charger_driver = {
 488         .driver = {
 489                 .name = "bq24735-charger",
 490                 .of_match_table = bq24735_match_ids,
 491         },
 492         .probe = bq24735_charger_probe,
 493         .id_table = bq24735_charger_id,
 494 };
 495
 496 module_i2c_driver(bq24735_charger_driver);
 497
 498 MODULE_DESCRIPTION("bq24735 battery charging driver");
 499 MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
 500 MODULE_LICENSE("GPL v2");