drivers/power/supply/max17040_battery.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 //  max17040_battery.c
   4 //  fuel-gauge systems for lithium-ion (Li+) batteries
   5 //
   6 //  Copyright (C) 2009 Samsung Electronics
   7 //  Minkyu Kang <mk7.kang@samsung.com>
   8
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/mutex.h>
  13 #include <linux/err.h>
  14 #include <linux/i2c.h>
  15 #include <linux/delay.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/power_supply.h>
  18 #include <linux/max17040_battery.h>
  19 #include <linux/slab.h>
  20
  21 #define MAX17040_VCELL  0x02
  22 #define MAX17040_SOC    0x04
  23 #define MAX17040_MODE   0x06
  24 #define MAX17040_VER    0x08
  25 #define MAX17040_RCOMP  0x0C
  26 #define MAX17040_CMD    0xFE
  27
  28
  29 #define MAX17040_DELAY          1000
  30 #define MAX17040_BATTERY_FULL   95
  31
  32 #define MAX17040_ATHD_MASK              0xFFC0
  33 #define MAX17040_ATHD_DEFAULT_POWER_UP  4
  34
  35 struct max17040_chip {
  36         struct i2c_client               *client;
  37         struct delayed_work             work;
  38         struct power_supply             *battery;
  39         struct max17040_platform_data   *pdata;
  40
  41         /* State Of Connect */
  42         int online;
  43         /* battery voltage */
  44         int vcell;
  45         /* battery capacity */
  46         int soc;
  47         /* State Of Charge */
  48         int status;
  49         /* Low alert threshold from 32% to 1% of the State of Charge */
  50         u32 low_soc_alert;
  51 };
  52
  53 static int max17040_get_property(struct power_supply *psy,
  54                             enum power_supply_property psp,
  55                             union power_supply_propval *val)
  56 {
  57         struct max17040_chip *chip = power_supply_get_drvdata(psy);
  58
  59         switch (psp) {
  60         case POWER_SUPPLY_PROP_STATUS:
  61                 val->intval = chip->status;
  62                 break;
  63         case POWER_SUPPLY_PROP_ONLINE:
  64                 val->intval = chip->online;
  65                 break;
  66         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  67                 val->intval = chip->vcell;
  68                 break;
  69         case POWER_SUPPLY_PROP_CAPACITY:
  70                 val->intval = chip->soc;
  71                 break;
  72         default:
  73                 return -EINVAL;
  74         }
  75         return 0;
  76 }
  77
  78 static int max17040_write_reg(struct i2c_client *client, int reg, u16 value)
  79 {
  80         int ret;
  81
  82         ret = i2c_smbus_write_word_swapped(client, reg, value);
  83
  84         if (ret < 0)
  85                 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
  86
  87         return ret;
  88 }
  89
  90 static int max17040_read_reg(struct i2c_client *client, int reg)
  91 {
  92         int ret;
  93
  94         ret = i2c_smbus_read_word_swapped(client, reg);
  95
  96         if (ret < 0)
  97                 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
  98
  99         return ret;
 100 }
 101
 102 static void max17040_reset(struct i2c_client *client)
 103 {
 104         max17040_write_reg(client, MAX17040_CMD, 0x0054);
 105 }
 106
 107 static int max17040_set_low_soc_alert(struct i2c_client *client, u32 level)
 108 {
 109         int ret;
 110         u16 data;
 111
 112         level = 32 - level;
 113         data = max17040_read_reg(client, MAX17040_RCOMP);
 114         /* clear the alrt bit and set LSb 5 bits */
 115         data &= MAX17040_ATHD_MASK;
 116         data |= level;
 117         ret = max17040_write_reg(client, MAX17040_RCOMP, data);
 118
 119         return ret;
 120 }
 121
 122 static void max17040_get_vcell(struct i2c_client *client)
 123 {
 124         struct max17040_chip *chip = i2c_get_clientdata(client);
 125         u16 vcell;
 126
 127         vcell = max17040_read_reg(client, MAX17040_VCELL);
 128
 129         chip->vcell = vcell;
 130 }
 131
 132 static void max17040_get_soc(struct i2c_client *client)
 133 {
 134         struct max17040_chip *chip = i2c_get_clientdata(client);
 135         u16 soc;
 136
 137         soc = max17040_read_reg(client, MAX17040_SOC);
 138
 139         chip->soc = (soc >> 8);
 140 }
 141
 142 static void max17040_get_version(struct i2c_client *client)
 143 {
 144         u16 version;
 145
 146         version = max17040_read_reg(client, MAX17040_VER);
 147
 148         dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", version);
 149 }
 150
 151 static void max17040_get_online(struct i2c_client *client)
 152 {
 153         struct max17040_chip *chip = i2c_get_clientdata(client);
 154
 155         if (chip->pdata && chip->pdata->battery_online)
 156                 chip->online = chip->pdata->battery_online();
 157         else
 158                 chip->online = 1;
 159 }
 160
 161 static void max17040_get_status(struct i2c_client *client)
 162 {
 163         struct max17040_chip *chip = i2c_get_clientdata(client);
 164
 165         if (!chip->pdata || !chip->pdata->charger_online
 166                         || !chip->pdata->charger_enable) {
 167                 chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
 168                 return;
 169         }
 170
 171         if (chip->pdata->charger_online()) {
 172                 if (chip->pdata->charger_enable())
 173                         chip->status = POWER_SUPPLY_STATUS_CHARGING;
 174                 else
 175                         chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 176         } else {
 177                 chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
 178         }
 179
 180         if (chip->soc > MAX17040_BATTERY_FULL)
 181                 chip->status = POWER_SUPPLY_STATUS_FULL;
 182 }
 183
 184 static int max17040_get_of_data(struct max17040_chip *chip)
 185 {
 186         struct device *dev = &chip->client->dev;
 187
 188         chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP;
 189         device_property_read_u32(dev,
 190                                  "maxim,alert-low-soc-level",
 191                                  &chip->low_soc_alert);
 192
 193         if (chip->low_soc_alert <= 0 || chip->low_soc_alert >= 33)
 194                 return -EINVAL;
 195
 196         return 0;
 197 }
 198
 199 static void max17040_check_changes(struct i2c_client *client)
 200 {
 201         max17040_get_vcell(client);
 202         max17040_get_soc(client);
 203         max17040_get_online(client);
 204         max17040_get_status(client);
 205 }
 206
 207 static void max17040_work(struct work_struct *work)
 208 {
 209         struct max17040_chip *chip;
 210         int last_soc, last_status;
 211
 212         chip = container_of(work, struct max17040_chip, work.work);
 213
 214         /* store SOC and status to check changes */
 215         last_soc = chip->soc;
 216         last_status = chip->status;
 217         max17040_check_changes(chip->client);
 218
 219         /* check changes and send uevent */
 220         if (last_soc != chip->soc || last_status != chip->status)
 221                 power_supply_changed(chip->battery);
 222
 223         queue_delayed_work(system_power_efficient_wq, &chip->work,
 224                            MAX17040_DELAY);
 225 }
 226
 227 static irqreturn_t max17040_thread_handler(int id, void *dev)
 228 {
 229         struct max17040_chip *chip = dev;
 230         struct i2c_client *client = chip->client;
 231
 232         dev_warn(&client->dev, "IRQ: Alert battery low level");
 233         /* read registers */
 234         max17040_check_changes(chip->client);
 235
 236         /* send uevent */
 237         power_supply_changed(chip->battery);
 238
 239         /* reset alert bit */
 240         max17040_set_low_soc_alert(client, chip->low_soc_alert);
 241
 242         return IRQ_HANDLED;
 243 }
 244
 245 static int max17040_enable_alert_irq(struct max17040_chip *chip)
 246 {
 247         struct i2c_client *client = chip->client;
 248         unsigned int flags;
 249         int ret;
 250
 251         flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT;
 252         ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 253                                         max17040_thread_handler, flags,
 254                                         chip->battery->desc->name, chip);
 255
 256         return ret;
 257 }
 258
 259 static enum power_supply_property max17040_battery_props[] = {
 260         POWER_SUPPLY_PROP_STATUS,
 261         POWER_SUPPLY_PROP_ONLINE,
 262         POWER_SUPPLY_PROP_VOLTAGE_NOW,
 263         POWER_SUPPLY_PROP_CAPACITY,
 264 };
 265
 266 static const struct power_supply_desc max17040_battery_desc = {
 267         .name           = "battery",
 268         .type           = POWER_SUPPLY_TYPE_BATTERY,
 269         .get_property   = max17040_get_property,
 270         .properties     = max17040_battery_props,
 271         .num_properties = ARRAY_SIZE(max17040_battery_props),
 272 };
 273
 274 static int max17040_probe(struct i2c_client *client,
 275                         const struct i2c_device_id *id)
 276 {
 277         struct i2c_adapter *adapter = client->adapter;
 278         struct power_supply_config psy_cfg = {};
 279         struct max17040_chip *chip;
 280         int ret;
 281
 282         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
 283                 return -EIO;
 284
 285         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 286         if (!chip)
 287                 return -ENOMEM;
 288
 289         chip->client = client;
 290         chip->pdata = client->dev.platform_data;
 291         ret = max17040_get_of_data(chip);
 292         if (ret) {
 293                 dev_err(&client->dev,
 294                         "failed: low SOC alert OF data out of bounds\n");
 295                 return ret;
 296         }
 297
 298         i2c_set_clientdata(client, chip);
 299         psy_cfg.drv_data = chip;
 300
 301         chip->battery = power_supply_register(&client->dev,
 302                                 &max17040_battery_desc, &psy_cfg);
 303         if (IS_ERR(chip->battery)) {
 304                 dev_err(&client->dev, "failed: power supply register\n");
 305                 return PTR_ERR(chip->battery);
 306         }
 307
 308         max17040_reset(client);
 309         max17040_get_version(client);
 310
 311         /* check interrupt */
 312         if (client->irq && of_device_is_compatible(client->dev.of_node,
 313                                                    "maxim,max77836-battery")) {
 314                 ret = max17040_set_low_soc_alert(client, chip->low_soc_alert);
 315                 if (ret) {
 316                         dev_err(&client->dev,
 317                                 "Failed to set low SOC alert: err %d\n", ret);
 318                         return ret;
 319                 }
 320
 321                 ret = max17040_enable_alert_irq(chip);
 322                 if (ret) {
 323                         client->irq = 0;
 324                         dev_warn(&client->dev,
 325                                  "Failed to get IRQ err %d\n", ret);
 326                 }
 327         }
 328
 329         INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
 330         queue_delayed_work(system_power_efficient_wq, &chip->work,
 331                            MAX17040_DELAY);
 332
 333         return 0;
 334 }
 335
 336 static int max17040_remove(struct i2c_client *client)
 337 {
 338         struct max17040_chip *chip = i2c_get_clientdata(client);
 339
 340         power_supply_unregister(chip->battery);
 341         cancel_delayed_work(&chip->work);
 342         return 0;
 343 }
 344
 345 #ifdef CONFIG_PM_SLEEP
 346
 347 static int max17040_suspend(struct device *dev)
 348 {
 349         struct i2c_client *client = to_i2c_client(dev);
 350         struct max17040_chip *chip = i2c_get_clientdata(client);
 351
 352         cancel_delayed_work(&chip->work);
 353
 354         if (client->irq && device_may_wakeup(dev))
 355                 enable_irq_wake(client->irq);
 356
 357         return 0;
 358 }
 359
 360 static int max17040_resume(struct device *dev)
 361 {
 362         struct i2c_client *client = to_i2c_client(dev);
 363         struct max17040_chip *chip = i2c_get_clientdata(client);
 364
 365         queue_delayed_work(system_power_efficient_wq, &chip->work,
 366                            MAX17040_DELAY);
 367
 368         if (client->irq && device_may_wakeup(dev))
 369                 disable_irq_wake(client->irq);
 370
 371         return 0;
 372 }
 373
 374 static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
 375 #define MAX17040_PM_OPS (&max17040_pm_ops)
 376
 377 #else
 378
 379 #define MAX17040_PM_OPS NULL
 380
 381 #endif /* CONFIG_PM_SLEEP */
 382
 383 static const struct i2c_device_id max17040_id[] = {
 384         { "max17040" },
 385         { "max77836-battery" },
 386         { }
 387 };
 388 MODULE_DEVICE_TABLE(i2c, max17040_id);
 389
 390 static const struct of_device_id max17040_of_match[] = {
 391         { .compatible = "maxim,max17040" },
 392         { .compatible = "maxim,max77836-battery" },
 393         { },
 394 };
 395 MODULE_DEVICE_TABLE(of, max17040_of_match);
 396
 397 static struct i2c_driver max17040_i2c_driver = {
 398         .driver = {
 399                 .name   = "max17040",
 400                 .of_match_table = max17040_of_match,
 401                 .pm     = MAX17040_PM_OPS,
 402         },
 403         .probe          = max17040_probe,
 404         .remove         = max17040_remove,
 405         .id_table       = max17040_id,
 406 };
 407 module_i2c_driver(max17040_i2c_driver);
 408
 409 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
 410 MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
 411 MODULE_LICENSE("GPL");