linux/drivers/power/supply/bq24735-charger.c
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   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/gpio/consumer.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
  46struct 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        struct gpio_desc                *status_gpio;
  53        struct delayed_work             poll;
  54        u32                             poll_interval;
  55        bool                            charging;
  56};
  57
  58static inline struct bq24735 *to_bq24735(struct power_supply *psy)
  59{
  60        return power_supply_get_drvdata(psy);
  61}
  62
  63static enum power_supply_property bq24735_charger_properties[] = {
  64        POWER_SUPPLY_PROP_STATUS,
  65        POWER_SUPPLY_PROP_ONLINE,
  66};
  67
  68static int bq24735_charger_property_is_writeable(struct power_supply *psy,
  69                                                 enum power_supply_property psp)
  70{
  71        switch (psp) {
  72        case POWER_SUPPLY_PROP_STATUS:
  73                return 1;
  74        default:
  75                break;
  76        }
  77
  78        return 0;
  79}
  80
  81static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
  82                                     u16 value)
  83{
  84        return i2c_smbus_write_word_data(client, reg, value);
  85}
  86
  87static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
  88{
  89        return i2c_smbus_read_word_data(client, reg);
  90}
  91
  92static int bq24735_update_word(struct i2c_client *client, u8 reg,
  93                               u16 mask, u16 value)
  94{
  95        unsigned int tmp;
  96        int ret;
  97
  98        ret = bq24735_read_word(client, reg);
  99        if (ret < 0)
 100                return ret;
 101
 102        tmp = ret & ~mask;
 103        tmp |= value & mask;
 104
 105        return bq24735_write_word(client, reg, tmp);
 106}
 107
 108static int bq24735_config_charger(struct bq24735 *charger)
 109{
 110        struct bq24735_platform *pdata = charger->pdata;
 111        int ret;
 112        u16 value;
 113
 114        if (pdata->ext_control)
 115                return 0;
 116
 117        if (pdata->charge_current) {
 118                value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
 119
 120                ret = bq24735_write_word(charger->client,
 121                                         BQ24735_CHARGE_CURRENT, value);
 122                if (ret < 0) {
 123                        dev_err(&charger->client->dev,
 124                                "Failed to write charger current : %d\n",
 125                                ret);
 126                        return ret;
 127                }
 128        }
 129
 130        if (pdata->charge_voltage) {
 131                value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
 132
 133                ret = bq24735_write_word(charger->client,
 134                                         BQ24735_CHARGE_VOLTAGE, value);
 135                if (ret < 0) {
 136                        dev_err(&charger->client->dev,
 137                                "Failed to write charger voltage : %d\n",
 138                                ret);
 139                        return ret;
 140                }
 141        }
 142
 143        if (pdata->input_current) {
 144                value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
 145
 146                ret = bq24735_write_word(charger->client,
 147                                         BQ24735_INPUT_CURRENT, value);
 148                if (ret < 0) {
 149                        dev_err(&charger->client->dev,
 150                                "Failed to write input current : %d\n",
 151                                ret);
 152                        return ret;
 153                }
 154        }
 155
 156        return 0;
 157}
 158
 159static inline int bq24735_enable_charging(struct bq24735 *charger)
 160{
 161        int ret;
 162
 163        if (charger->pdata->ext_control)
 164                return 0;
 165
 166        ret = bq24735_config_charger(charger);
 167        if (ret)
 168                return ret;
 169
 170        return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
 171                                   BQ24735_CHG_OPT_CHARGE_DISABLE, 0);
 172}
 173
 174static inline int bq24735_disable_charging(struct bq24735 *charger)
 175{
 176        if (charger->pdata->ext_control)
 177                return 0;
 178
 179        return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
 180                                   BQ24735_CHG_OPT_CHARGE_DISABLE,
 181                                   BQ24735_CHG_OPT_CHARGE_DISABLE);
 182}
 183
 184static bool bq24735_charger_is_present(struct bq24735 *charger)
 185{
 186        if (charger->status_gpio) {
 187                return !gpiod_get_value_cansleep(charger->status_gpio);
 188        } else {
 189                int ac = 0;
 190
 191                ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
 192                if (ac < 0) {
 193                        dev_dbg(&charger->client->dev,
 194                                "Failed to read charger options : %d\n",
 195                                ac);
 196                        return false;
 197                }
 198                return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false;
 199        }
 200
 201        return false;
 202}
 203
 204static int bq24735_charger_is_charging(struct bq24735 *charger)
 205{
 206        int ret;
 207
 208        if (!bq24735_charger_is_present(charger))
 209                return 0;
 210
 211        ret  = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
 212        if (ret < 0)
 213                return ret;
 214
 215        return !(ret & BQ24735_CHG_OPT_CHARGE_DISABLE);
 216}
 217
 218static void bq24735_update(struct bq24735 *charger)
 219{
 220        mutex_lock(&charger->lock);
 221
 222        if (charger->charging && bq24735_charger_is_present(charger))
 223                bq24735_enable_charging(charger);
 224        else
 225                bq24735_disable_charging(charger);
 226
 227        mutex_unlock(&charger->lock);
 228
 229        power_supply_changed(charger->charger);
 230}
 231
 232static irqreturn_t bq24735_charger_isr(int irq, void *devid)
 233{
 234        struct power_supply *psy = devid;
 235        struct bq24735 *charger = to_bq24735(psy);
 236
 237        bq24735_update(charger);
 238
 239        return IRQ_HANDLED;
 240}
 241
 242static void bq24735_poll(struct work_struct *work)
 243{
 244        struct bq24735 *charger = container_of(work, struct bq24735, poll.work);
 245
 246        bq24735_update(charger);
 247
 248        schedule_delayed_work(&charger->poll,
 249                              msecs_to_jiffies(charger->poll_interval));
 250}
 251
 252static int bq24735_charger_get_property(struct power_supply *psy,
 253                                        enum power_supply_property psp,
 254                                        union power_supply_propval *val)
 255{
 256        struct bq24735 *charger = to_bq24735(psy);
 257
 258        switch (psp) {
 259        case POWER_SUPPLY_PROP_ONLINE:
 260                val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
 261                break;
 262        case POWER_SUPPLY_PROP_STATUS:
 263                switch (bq24735_charger_is_charging(charger)) {
 264                case 1:
 265                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
 266                        break;
 267                case 0:
 268                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 269                        break;
 270                default:
 271                        val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 272                        break;
 273                }
 274                break;
 275        default:
 276                return -EINVAL;
 277        }
 278
 279        return 0;
 280}
 281
 282static int bq24735_charger_set_property(struct power_supply *psy,
 283                                        enum power_supply_property psp,
 284                                        const union power_supply_propval *val)
 285{
 286        struct bq24735 *charger = to_bq24735(psy);
 287        int ret;
 288
 289        switch (psp) {
 290        case POWER_SUPPLY_PROP_STATUS:
 291                switch (val->intval) {
 292                case POWER_SUPPLY_STATUS_CHARGING:
 293                        mutex_lock(&charger->lock);
 294                        charger->charging = true;
 295                        ret = bq24735_enable_charging(charger);
 296                        mutex_unlock(&charger->lock);
 297                        if (ret)
 298                                return ret;
 299                        break;
 300                case POWER_SUPPLY_STATUS_DISCHARGING:
 301                case POWER_SUPPLY_STATUS_NOT_CHARGING:
 302                        mutex_lock(&charger->lock);
 303                        charger->charging = false;
 304                        ret = bq24735_disable_charging(charger);
 305                        mutex_unlock(&charger->lock);
 306                        if (ret)
 307                                return ret;
 308                        break;
 309                default:
 310                        return -EINVAL;
 311                }
 312                power_supply_changed(psy);
 313                break;
 314        default:
 315                return -EPERM;
 316        }
 317
 318        return 0;
 319}
 320
 321static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 322{
 323        struct bq24735_platform *pdata;
 324        struct device_node *np = client->dev.of_node;
 325        u32 val;
 326        int ret;
 327
 328        pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 329        if (!pdata) {
 330                dev_err(&client->dev,
 331                        "Memory alloc for bq24735 pdata failed\n");
 332                return NULL;
 333        }
 334
 335        ret = of_property_read_u32(np, "ti,charge-current", &val);
 336        if (!ret)
 337                pdata->charge_current = val;
 338
 339        ret = of_property_read_u32(np, "ti,charge-voltage", &val);
 340        if (!ret)
 341                pdata->charge_voltage = val;
 342
 343        ret = of_property_read_u32(np, "ti,input-current", &val);
 344        if (!ret)
 345                pdata->input_current = val;
 346
 347        pdata->ext_control = of_property_read_bool(np, "ti,external-control");
 348
 349        return pdata;
 350}
 351
 352static int bq24735_charger_probe(struct i2c_client *client,
 353                                 const struct i2c_device_id *id)
 354{
 355        int ret;
 356        struct bq24735 *charger;
 357        struct power_supply_desc *supply_desc;
 358        struct power_supply_config psy_cfg = {};
 359        char *name;
 360
 361        charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
 362        if (!charger)
 363                return -ENOMEM;
 364
 365        mutex_init(&charger->lock);
 366        charger->charging = true;
 367        charger->pdata = client->dev.platform_data;
 368
 369        if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
 370                charger->pdata = bq24735_parse_dt_data(client);
 371
 372        if (!charger->pdata) {
 373                dev_err(&client->dev, "no platform data provided\n");
 374                return -EINVAL;
 375        }
 376
 377        name = (char *)charger->pdata->name;
 378        if (!name) {
 379                name = devm_kasprintf(&client->dev, GFP_KERNEL,
 380                                      "bq24735@%s",
 381                                      dev_name(&client->dev));
 382                if (!name) {
 383                        dev_err(&client->dev, "Failed to alloc device name\n");
 384                        return -ENOMEM;
 385                }
 386        }
 387
 388        charger->client = client;
 389
 390        supply_desc = &charger->charger_desc;
 391
 392        supply_desc->name = name;
 393        supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
 394        supply_desc->properties = bq24735_charger_properties;
 395        supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
 396        supply_desc->get_property = bq24735_charger_get_property;
 397        supply_desc->set_property = bq24735_charger_set_property;
 398        supply_desc->property_is_writeable =
 399                                bq24735_charger_property_is_writeable;
 400
 401        psy_cfg.supplied_to = charger->pdata->supplied_to;
 402        psy_cfg.num_supplicants = charger->pdata->num_supplicants;
 403        psy_cfg.of_node = client->dev.of_node;
 404        psy_cfg.drv_data = charger;
 405
 406        i2c_set_clientdata(client, charger);
 407
 408        charger->status_gpio = devm_gpiod_get_optional(&client->dev,
 409                                                       "ti,ac-detect",
 410                                                       GPIOD_IN);
 411        if (IS_ERR(charger->status_gpio)) {
 412                ret = PTR_ERR(charger->status_gpio);
 413                dev_err(&client->dev, "Getting gpio failed: %d\n", ret);
 414                return ret;
 415        }
 416
 417        if (bq24735_charger_is_present(charger)) {
 418                ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
 419                if (ret < 0) {
 420                        dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
 421                                ret);
 422                        return ret;
 423                } else if (ret != 0x0040) {
 424                        dev_err(&client->dev,
 425                                "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
 426                        return -ENODEV;
 427                }
 428
 429                ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
 430                if (ret < 0) {
 431                        dev_err(&client->dev, "Failed to read device id : %d\n", ret);
 432                        return ret;
 433                } else if (ret != 0x000B) {
 434                        dev_err(&client->dev,
 435                                "device id mismatch. 0x000b != 0x%04x\n", ret);
 436                        return -ENODEV;
 437                }
 438
 439                ret = bq24735_enable_charging(charger);
 440                if (ret < 0) {
 441                        dev_err(&client->dev, "Failed to enable charging\n");
 442                        return ret;
 443                }
 444        }
 445
 446        charger->charger = devm_power_supply_register(&client->dev, supply_desc,
 447                                                      &psy_cfg);
 448        if (IS_ERR(charger->charger)) {
 449                ret = PTR_ERR(charger->charger);
 450                dev_err(&client->dev, "Failed to register power supply: %d\n",
 451                        ret);
 452                return ret;
 453        }
 454
 455        if (client->irq) {
 456                ret = devm_request_threaded_irq(&client->dev, client->irq,
 457                                                NULL, bq24735_charger_isr,
 458                                                IRQF_TRIGGER_RISING |
 459                                                IRQF_TRIGGER_FALLING |
 460                                                IRQF_ONESHOT,
 461                                                supply_desc->name,
 462                                                charger->charger);
 463                if (ret) {
 464                        dev_err(&client->dev,
 465                                "Unable to register IRQ %d err %d\n",
 466                                client->irq, ret);
 467                        return ret;
 468                }
 469        } else {
 470                ret = device_property_read_u32(&client->dev, "poll-interval",
 471                                               &charger->poll_interval);
 472                if (ret)
 473                        return 0;
 474                if (!charger->poll_interval)
 475                        return 0;
 476
 477                INIT_DELAYED_WORK(&charger->poll, bq24735_poll);
 478                schedule_delayed_work(&charger->poll,
 479                                      msecs_to_jiffies(charger->poll_interval));
 480        }
 481
 482        return 0;
 483}
 484
 485static int bq24735_charger_remove(struct i2c_client *client)
 486{
 487        struct bq24735 *charger = i2c_get_clientdata(client);
 488
 489        if (charger->poll_interval)
 490                cancel_delayed_work_sync(&charger->poll);
 491
 492        return 0;
 493}
 494
 495static const struct i2c_device_id bq24735_charger_id[] = {
 496        { "bq24735-charger", 0 },
 497        {}
 498};
 499MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
 500
 501static const struct of_device_id bq24735_match_ids[] = {
 502        { .compatible = "ti,bq24735", },
 503        { /* end */ }
 504};
 505MODULE_DEVICE_TABLE(of, bq24735_match_ids);
 506
 507static struct i2c_driver bq24735_charger_driver = {
 508        .driver = {
 509                .name = "bq24735-charger",
 510                .of_match_table = bq24735_match_ids,
 511        },
 512        .probe = bq24735_charger_probe,
 513        .remove = bq24735_charger_remove,
 514        .id_table = bq24735_charger_id,
 515};
 516
 517module_i2c_driver(bq24735_charger_driver);
 518
 519MODULE_DESCRIPTION("bq24735 battery charging driver");
 520MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
 521MODULE_LICENSE("GPL v2");
 522