linux/drivers/power/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/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
  46struct bq24735 {
  47        struct power_supply     charger;
  48        struct i2c_client       *client;
  49        struct bq24735_platform *pdata;
  50};
  51
  52static inline struct bq24735 *to_bq24735(struct power_supply *psy)
  53{
  54        return container_of(psy, struct bq24735, charger);
  55}
  56
  57static enum power_supply_property bq24735_charger_properties[] = {
  58        POWER_SUPPLY_PROP_ONLINE,
  59};
  60
  61static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
  62                                     u16 value)
  63{
  64        return i2c_smbus_write_word_data(client, reg, le16_to_cpu(value));
  65}
  66
  67static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
  68{
  69        s32 ret = i2c_smbus_read_word_data(client, reg);
  70
  71        return ret < 0 ? ret : le16_to_cpu(ret);
  72}
  73
  74static int bq24735_update_word(struct i2c_client *client, u8 reg,
  75                               u16 mask, u16 value)
  76{
  77        unsigned int tmp;
  78        int ret;
  79
  80        ret = bq24735_read_word(client, reg);
  81        if (ret < 0)
  82                return ret;
  83
  84        tmp = ret & ~mask;
  85        tmp |= value & mask;
  86
  87        return bq24735_write_word(client, reg, tmp);
  88}
  89
  90static inline int bq24735_enable_charging(struct bq24735 *charger)
  91{
  92        return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
  93                                   BQ24735_CHG_OPT_CHARGE_DISABLE,
  94                                   ~BQ24735_CHG_OPT_CHARGE_DISABLE);
  95}
  96
  97static inline int bq24735_disable_charging(struct bq24735 *charger)
  98{
  99        return bq24735_update_word(charger->client, BQ24735_CHG_OPT,
 100                                   BQ24735_CHG_OPT_CHARGE_DISABLE,
 101                                   BQ24735_CHG_OPT_CHARGE_DISABLE);
 102}
 103
 104static int bq24735_config_charger(struct bq24735 *charger)
 105{
 106        struct bq24735_platform *pdata = charger->pdata;
 107        int ret;
 108        u16 value;
 109
 110        if (pdata->charge_current) {
 111                value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;
 112
 113                ret = bq24735_write_word(charger->client,
 114                                         BQ24735_CHARGE_CURRENT, value);
 115                if (ret < 0) {
 116                        dev_err(&charger->client->dev,
 117                                "Failed to write charger current : %d\n",
 118                                ret);
 119                        return ret;
 120                }
 121        }
 122
 123        if (pdata->charge_voltage) {
 124                value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;
 125
 126                ret = bq24735_write_word(charger->client,
 127                                         BQ24735_CHARGE_VOLTAGE, value);
 128                if (ret < 0) {
 129                        dev_err(&charger->client->dev,
 130                                "Failed to write charger voltage : %d\n",
 131                                ret);
 132                        return ret;
 133                }
 134        }
 135
 136        if (pdata->input_current) {
 137                value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;
 138
 139                ret = bq24735_write_word(charger->client,
 140                                         BQ24735_INPUT_CURRENT, value);
 141                if (ret < 0) {
 142                        dev_err(&charger->client->dev,
 143                                "Failed to write input current : %d\n",
 144                                ret);
 145                        return ret;
 146                }
 147        }
 148
 149        return 0;
 150}
 151
 152static bool bq24735_charger_is_present(struct bq24735 *charger)
 153{
 154        struct bq24735_platform *pdata = charger->pdata;
 155        int ret;
 156
 157        if (pdata->status_gpio_valid) {
 158                ret = gpio_get_value_cansleep(pdata->status_gpio);
 159                return ret ^= pdata->status_gpio_active_low == 0;
 160        } else {
 161                int ac = 0;
 162
 163                ac = bq24735_read_word(charger->client, BQ24735_CHG_OPT);
 164                if (ac < 0) {
 165                        dev_err(&charger->client->dev,
 166                                "Failed to read charger options : %d\n",
 167                                ac);
 168                        return false;
 169                }
 170                return (ac & BQ24735_CHG_OPT_AC_PRESENT) ? true : false;
 171        }
 172
 173        return false;
 174}
 175
 176static irqreturn_t bq24735_charger_isr(int irq, void *devid)
 177{
 178        struct power_supply *psy = devid;
 179        struct bq24735 *charger = to_bq24735(psy);
 180
 181        if (bq24735_charger_is_present(charger))
 182                bq24735_enable_charging(charger);
 183        else
 184                bq24735_disable_charging(charger);
 185
 186        power_supply_changed(psy);
 187
 188        return IRQ_HANDLED;
 189}
 190
 191static int bq24735_charger_get_property(struct power_supply *psy,
 192                                        enum power_supply_property psp,
 193                                        union power_supply_propval *val)
 194{
 195        struct bq24735 *charger;
 196
 197        charger = container_of(psy, struct bq24735, charger);
 198
 199        switch (psp) {
 200        case POWER_SUPPLY_PROP_ONLINE:
 201                val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
 202                break;
 203        default:
 204                return -EINVAL;
 205        }
 206
 207        return 0;
 208}
 209
 210static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 211{
 212        struct bq24735_platform *pdata;
 213        struct device_node *np = client->dev.of_node;
 214        u32 val;
 215        int ret;
 216        enum of_gpio_flags flags;
 217
 218        pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 219        if (!pdata) {
 220                dev_err(&client->dev,
 221                        "Memory alloc for bq24735 pdata failed\n");
 222                return NULL;
 223        }
 224
 225        pdata->status_gpio = of_get_named_gpio_flags(np, "ti,ac-detect-gpios",
 226                                                     0, &flags);
 227
 228        if (flags & OF_GPIO_ACTIVE_LOW)
 229                pdata->status_gpio_active_low = 1;
 230
 231        ret = of_property_read_u32(np, "ti,charge-current", &val);
 232        if (!ret)
 233                pdata->charge_current = val;
 234
 235        ret = of_property_read_u32(np, "ti,charge-voltage", &val);
 236        if (!ret)
 237                pdata->charge_voltage = val;
 238
 239        ret = of_property_read_u32(np, "ti,input-current", &val);
 240        if (!ret)
 241                pdata->input_current = val;
 242
 243        return pdata;
 244}
 245
 246static int bq24735_charger_probe(struct i2c_client *client,
 247                                 const struct i2c_device_id *id)
 248{
 249        int ret;
 250        struct bq24735 *charger;
 251        struct power_supply *supply;
 252        char *name;
 253
 254        charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
 255        if (!charger)
 256                return -ENOMEM;
 257
 258        charger->pdata = client->dev.platform_data;
 259
 260        if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
 261                charger->pdata = bq24735_parse_dt_data(client);
 262
 263        if (!charger->pdata) {
 264                dev_err(&client->dev, "no platform data provided\n");
 265                return -EINVAL;
 266        }
 267
 268        name = (char *)charger->pdata->name;
 269        if (!name) {
 270                name = kasprintf(GFP_KERNEL, "bq24735@%s",
 271                                 dev_name(&client->dev));
 272                if (!name) {
 273                        dev_err(&client->dev, "Failed to alloc device name\n");
 274                        return -ENOMEM;
 275                }
 276        }
 277
 278        charger->client = client;
 279
 280        supply = &charger->charger;
 281
 282        supply->name = name;
 283        supply->type = POWER_SUPPLY_TYPE_MAINS;
 284        supply->properties = bq24735_charger_properties;
 285        supply->num_properties = ARRAY_SIZE(bq24735_charger_properties);
 286        supply->get_property = bq24735_charger_get_property;
 287        supply->supplied_to = charger->pdata->supplied_to;
 288        supply->num_supplicants = charger->pdata->num_supplicants;
 289        supply->of_node = client->dev.of_node;
 290
 291        i2c_set_clientdata(client, charger);
 292
 293        ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
 294        if (ret < 0) {
 295                dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
 296                        ret);
 297                goto err_free_name;
 298        } else if (ret != 0x0040) {
 299                dev_err(&client->dev,
 300                        "manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
 301                ret = -ENODEV;
 302                goto err_free_name;
 303        }
 304
 305        ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
 306        if (ret < 0) {
 307                dev_err(&client->dev, "Failed to read device id : %d\n", ret);
 308                goto err_free_name;
 309        } else if (ret != 0x000B) {
 310                dev_err(&client->dev,
 311                        "device id mismatch. 0x000b != 0x%04x\n", ret);
 312                ret = -ENODEV;
 313                goto err_free_name;
 314        }
 315
 316        if (gpio_is_valid(charger->pdata->status_gpio)) {
 317                ret = devm_gpio_request(&client->dev,
 318                                        charger->pdata->status_gpio,
 319                                        name);
 320                if (ret) {
 321                        dev_err(&client->dev,
 322                                "Failed GPIO request for GPIO %d: %d\n",
 323                                charger->pdata->status_gpio, ret);
 324                }
 325
 326                charger->pdata->status_gpio_valid = !ret;
 327        }
 328
 329        ret = bq24735_config_charger(charger);
 330        if (ret < 0) {
 331                dev_err(&client->dev, "failed in configuring charger");
 332                goto err_free_name;
 333        }
 334
 335        /* check for AC adapter presence */
 336        if (bq24735_charger_is_present(charger)) {
 337                ret = bq24735_enable_charging(charger);
 338                if (ret < 0) {
 339                        dev_err(&client->dev, "Failed to enable charging\n");
 340                        goto err_free_name;
 341                }
 342        }
 343
 344        ret = power_supply_register(&client->dev, supply);
 345        if (ret < 0) {
 346                dev_err(&client->dev, "Failed to register power supply: %d\n",
 347                        ret);
 348                goto err_free_name;
 349        }
 350
 351        if (client->irq) {
 352                ret = devm_request_threaded_irq(&client->dev, client->irq,
 353                                                NULL, bq24735_charger_isr,
 354                                                IRQF_TRIGGER_RISING |
 355                                                IRQF_TRIGGER_FALLING |
 356                                                IRQF_ONESHOT,
 357                                                supply->name, supply);
 358                if (ret) {
 359                        dev_err(&client->dev,
 360                                "Unable to register IRQ %d err %d\n",
 361                                client->irq, ret);
 362                        goto err_unregister_supply;
 363                }
 364        }
 365
 366        return 0;
 367err_unregister_supply:
 368        power_supply_unregister(supply);
 369err_free_name:
 370        if (name != charger->pdata->name)
 371                kfree(name);
 372
 373        return ret;
 374}
 375
 376static int bq24735_charger_remove(struct i2c_client *client)
 377{
 378        struct bq24735 *charger = i2c_get_clientdata(client);
 379
 380        if (charger->client->irq)
 381                devm_free_irq(&charger->client->dev, charger->client->irq,
 382                              &charger->charger);
 383
 384        power_supply_unregister(&charger->charger);
 385
 386        if (charger->charger.name != charger->pdata->name)
 387                kfree(charger->charger.name);
 388
 389        return 0;
 390}
 391
 392static const struct i2c_device_id bq24735_charger_id[] = {
 393        { "bq24735-charger", 0 },
 394        {}
 395};
 396MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);
 397
 398static const struct of_device_id bq24735_match_ids[] = {
 399        { .compatible = "ti,bq24735", },
 400        { /* end */ }
 401};
 402MODULE_DEVICE_TABLE(of, bq24735_match_ids);
 403
 404static struct i2c_driver bq24735_charger_driver = {
 405        .driver = {
 406                .name = "bq24735-charger",
 407                .owner = THIS_MODULE,
 408                .of_match_table = bq24735_match_ids,
 409        },
 410        .probe = bq24735_charger_probe,
 411        .remove = bq24735_charger_remove,
 412        .id_table = bq24735_charger_id,
 413};
 414
 415module_i2c_driver(bq24735_charger_driver);
 416
 417MODULE_DESCRIPTION("bq24735 battery charging driver");
 418MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
 419MODULE_LICENSE("GPL v2");
 420
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