drivers/power/supply/mm8013.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016-2019 The Linux Foundation. All rights reserved.
   4  * Copyright (c) 2023, Linaro Limited
   5  */
   6 #include <linux/delay.h>
   7 #include <linux/i2c.h>
   8 #include <linux/power_supply.h>
   9 #include <linux/regmap.h>
  10
  11 #define REG_BATID                       0x00 /* This one is very unclear */
  12  #define BATID_101                      0x0101 /* 107kOhm */
  13  #define BATID_102                      0x0102 /* 10kOhm */
  14 #define REG_TEMPERATURE                 0x06
  15 #define REG_VOLTAGE                     0x08
  16 #define REG_FLAGS                       0x0a
  17  #define MM8013_FLAG_OTC                BIT(15)
  18  #define MM8013_FLAG_OTD                BIT(14)
  19  #define MM8013_FLAG_BATHI              BIT(13)
  20  #define MM8013_FLAG_BATLOW             BIT(12)
  21  #define MM8013_FLAG_CHG_INH            BIT(11)
  22  #define MM8013_FLAG_FC                 BIT(9)
  23  #define MM8013_FLAG_CHG                BIT(8)
  24  #define MM8013_FLAG_OCC                BIT(6)
  25  #define MM8013_FLAG_ODC                BIT(5)
  26  #define MM8013_FLAG_OT                 BIT(4)
  27  #define MM8013_FLAG_UT                 BIT(3)
  28  #define MM8013_FLAG_DSG                BIT(0)
  29 #define REG_FULL_CHARGE_CAPACITY        0x0e
  30 #define REG_NOMINAL_CHARGE_CAPACITY     0x0c
  31 #define REG_AVERAGE_CURRENT             0x14
  32 #define REG_AVERAGE_TIME_TO_EMPTY       0x16
  33 #define REG_AVERAGE_TIME_TO_FULL        0x18
  34 #define REG_MAX_LOAD_CURRENT            0x1e
  35 #define REG_CYCLE_COUNT                 0x2a
  36 #define REG_STATE_OF_CHARGE             0x2c
  37 #define REG_DESIGN_CAPACITY             0x3c
  38 /* TODO: 0x62-0x68 seem to contain 'MM8013C' in a length-prefixed, non-terminated string */
  39
  40 #define DECIKELVIN_TO_DECIDEGC(t)       (t - 2731)
  41
  42 struct mm8013_chip {
  43         struct i2c_client *client;
  44         struct regmap *regmap;
  45 };
  46
  47 static int mm8013_checkdevice(struct mm8013_chip *chip)
  48 {
  49         int battery_id, ret;
  50         u32 val;
  51
  52         ret = regmap_write(chip->regmap, REG_BATID, 0x0008);
  53         if (ret < 0)
  54                 return ret;
  55
  56         ret = regmap_read(chip->regmap, REG_BATID, &val);
  57         if (ret < 0)
  58                 return ret;
  59
  60         if (val == BATID_102)
  61                 battery_id = 2;
  62         else if (val == BATID_101)
  63                 battery_id = 1;
  64         else
  65                 return -EINVAL;
  66
  67         dev_dbg(&chip->client->dev, "battery_id: %d\n", battery_id);
  68
  69         return 0;
  70 }
  71
  72 static enum power_supply_property mm8013_battery_props[] = {
  73         POWER_SUPPLY_PROP_CAPACITY,
  74         POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR,
  75         POWER_SUPPLY_PROP_CHARGE_FULL,
  76         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
  77         POWER_SUPPLY_PROP_CHARGE_NOW,
  78         POWER_SUPPLY_PROP_CURRENT_MAX,
  79         POWER_SUPPLY_PROP_CURRENT_NOW,
  80         POWER_SUPPLY_PROP_CYCLE_COUNT,
  81         POWER_SUPPLY_PROP_HEALTH,
  82         POWER_SUPPLY_PROP_PRESENT,
  83         POWER_SUPPLY_PROP_STATUS,
  84         POWER_SUPPLY_PROP_TEMP,
  85         POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
  86         POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
  87         POWER_SUPPLY_PROP_VOLTAGE_NOW,
  88 };
  89
  90 static int mm8013_get_property(struct power_supply *psy,
  91                                enum power_supply_property psp,
  92                                union power_supply_propval *val)
  93 {
  94         struct mm8013_chip *chip = psy->drv_data;
  95         int ret = 0;
  96         u32 regval;
  97
  98         switch (psp) {
  99         case POWER_SUPPLY_PROP_CAPACITY:
 100                 ret = regmap_read(chip->regmap, REG_STATE_OF_CHARGE, &regval);
 101                 if (ret < 0)
 102                         return ret;
 103
 104                 val->intval = regval;
 105                 break;
 106         case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR:
 107                 ret = regmap_read(chip->regmap, REG_FLAGS, &regval);
 108                 if (ret < 0)
 109                         return ret;
 110
 111                 if (regval & MM8013_FLAG_CHG_INH)
 112                         val->intval = POWER_SUPPLY_CHARGE_BEHAVIOUR_INHIBIT_CHARGE;
 113                 else
 114                         val->intval = POWER_SUPPLY_CHARGE_BEHAVIOUR_AUTO;
 115                 break;
 116         case POWER_SUPPLY_PROP_CHARGE_FULL:
 117                 ret = regmap_read(chip->regmap, REG_FULL_CHARGE_CAPACITY, &regval);
 118                 if (ret < 0)
 119                         return ret;
 120
 121                 val->intval = 1000 * regval;
 122                 break;
 123         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 124                 ret = regmap_read(chip->regmap, REG_DESIGN_CAPACITY, &regval);
 125                 if (ret < 0)
 126                         return ret;
 127
 128                 val->intval = 1000 * regval;
 129                 break;
 130         case POWER_SUPPLY_PROP_CHARGE_NOW:
 131                 ret = regmap_read(chip->regmap, REG_NOMINAL_CHARGE_CAPACITY, &regval);
 132                 if (ret < 0)
 133                         return ret;
 134
 135                 val->intval = 1000 * regval;
 136                 break;
 137         case POWER_SUPPLY_PROP_CURRENT_MAX:
 138                 ret = regmap_read(chip->regmap, REG_MAX_LOAD_CURRENT, &regval);
 139                 if (ret < 0)
 140                         return ret;
 141
 142                 val->intval = -1000 * (s16)regval;
 143                 break;
 144         case POWER_SUPPLY_PROP_CURRENT_NOW:
 145                 ret = regmap_read(chip->regmap, REG_AVERAGE_CURRENT, &regval);
 146                 if (ret < 0)
 147                         return ret;
 148
 149                 val->intval = -1000 * (s16)regval;
 150                 break;
 151         case POWER_SUPPLY_PROP_CYCLE_COUNT:
 152                 ret = regmap_read(chip->regmap, REG_CYCLE_COUNT, &regval);
 153                 if (ret < 0)
 154                         return ret;
 155
 156                 val->intval = regval;
 157                 break;
 158         case POWER_SUPPLY_PROP_HEALTH:
 159                 ret = regmap_read(chip->regmap, REG_FLAGS, &regval);
 160                 if (ret < 0)
 161                         return ret;
 162
 163                 if (regval & MM8013_FLAG_UT)
 164                         val->intval = POWER_SUPPLY_HEALTH_COLD;
 165                 else if (regval & (MM8013_FLAG_ODC | MM8013_FLAG_OCC))
 166                         val->intval = POWER_SUPPLY_HEALTH_OVERCURRENT;
 167                 else if (regval & (MM8013_FLAG_BATLOW))
 168                         val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 169                 else if (regval & MM8013_FLAG_BATHI)
 170                         val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 171                 else if (regval & (MM8013_FLAG_OT | MM8013_FLAG_OTD | MM8013_FLAG_OTC))
 172                         val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 173                 else
 174                         val->intval = POWER_SUPPLY_HEALTH_GOOD;
 175                 break;
 176         case POWER_SUPPLY_PROP_PRESENT:
 177                 ret = regmap_read(chip->regmap, REG_TEMPERATURE, &regval);
 178                 if (ret < 0)
 179                         return ret;
 180
 181                 val->intval = ((s16)regval > 0);
 182                 break;
 183         case POWER_SUPPLY_PROP_STATUS:
 184                 ret = regmap_read(chip->regmap, REG_FLAGS, &regval);
 185                 if (ret < 0)
 186                         return ret;
 187
 188                 if (regval & MM8013_FLAG_DSG)
 189                         val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 190                 else if (regval & MM8013_FLAG_CHG)
 191                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 192                 else if (regval & MM8013_FLAG_FC)
 193                         val->intval = POWER_SUPPLY_STATUS_FULL;
 194                 else
 195                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 196                 break;
 197         case POWER_SUPPLY_PROP_TEMP:
 198                 ret = regmap_read(chip->regmap, REG_TEMPERATURE, &regval);
 199                 if (ret < 0)
 200                         return ret;
 201
 202                 val->intval = DECIKELVIN_TO_DECIDEGC(regval);
 203                 break;
 204         case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 205                 ret = regmap_read(chip->regmap, REG_AVERAGE_TIME_TO_EMPTY, &regval);
 206                 if (ret < 0)
 207                         return ret;
 208
 209                 /* The estimation is not yet ready */
 210                 if (regval == U16_MAX)
 211                         return -ENODATA;
 212
 213                 val->intval = regval;
 214                 break;
 215         case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 216                 ret = regmap_read(chip->regmap, REG_AVERAGE_TIME_TO_FULL, &regval);
 217                 if (ret < 0)
 218                         return ret;
 219
 220                 /* The estimation is not yet ready */
 221                 if (regval == U16_MAX)
 222                         return -ENODATA;
 223
 224                 val->intval = regval;
 225                 break;
 226         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 227                 ret = regmap_read(chip->regmap, REG_VOLTAGE, &regval);
 228                 if (ret < 0)
 229                         return ret;
 230
 231                 val->intval = 1000 * regval;
 232                 break;
 233         default:
 234                 return -EINVAL;
 235         }
 236
 237         return 0;
 238 }
 239
 240 static const struct power_supply_desc mm8013_desc = {
 241         .name                   = "mm8013",
 242         .type                   = POWER_SUPPLY_TYPE_BATTERY,
 243         .properties             = mm8013_battery_props,
 244         .num_properties         = ARRAY_SIZE(mm8013_battery_props),
 245         .get_property           = mm8013_get_property,
 246 };
 247
 248 static const struct regmap_config mm8013_regmap_config = {
 249         .reg_bits = 8,
 250         .val_bits = 16,
 251         .max_register = 0x68,
 252         .use_single_read = true,
 253         .use_single_write = true,
 254         .val_format_endian = REGMAP_ENDIAN_LITTLE,
 255 };
 256
 257 static int mm8013_probe(struct i2c_client *client)
 258 {
 259         struct power_supply_config psy_cfg = {};
 260         struct device *dev = &client->dev;
 261         struct power_supply *psy;
 262         struct mm8013_chip *chip;
 263         int ret = 0;
 264
 265         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 266                 return dev_err_probe(dev, -EIO,
 267                                      "I2C_FUNC_SMBUS_WORD_DATA not supported\n");
 268
 269         chip = devm_kzalloc(dev, sizeof(struct mm8013_chip), GFP_KERNEL);
 270         if (!chip)
 271                 return -ENOMEM;
 272
 273         chip->client = client;
 274
 275         chip->regmap = devm_regmap_init_i2c(client, &mm8013_regmap_config);
 276         if (IS_ERR(chip->regmap)) {
 277                 ret = PTR_ERR(chip->regmap);
 278                 return dev_err_probe(dev, ret, "Couldn't initialize regmap\n");
 279         }
 280
 281         ret = mm8013_checkdevice(chip);
 282         if (ret)
 283                 return dev_err_probe(dev, ret, "MM8013 not found\n");
 284
 285         psy_cfg.drv_data = chip;
 286         psy_cfg.of_node = dev->of_node;
 287
 288         psy = devm_power_supply_register(dev, &mm8013_desc, &psy_cfg);
 289         if (IS_ERR(psy))
 290                 return PTR_ERR(psy);
 291
 292         return 0;
 293 }
 294
 295 static const struct i2c_device_id mm8013_id_table[] = {
 296         { "mm8013", 0 },
 297         {}
 298 };
 299 MODULE_DEVICE_TABLE(i2c, mm8013_id_table);
 300
 301 static const struct of_device_id mm8013_match_table[] = {
 302         { .compatible = "mitsumi,mm8013" },
 303         {}
 304 };
 305
 306 static struct i2c_driver mm8013_i2c_driver = {
 307         .probe = mm8013_probe,
 308         .id_table = mm8013_id_table,
 309         .driver = {
 310                 .name = "mm8013",
 311                 .of_match_table = mm8013_match_table,
 312         },
 313 };
 314 module_i2c_driver(mm8013_i2c_driver);
 315
 316 MODULE_DESCRIPTION("MM8013 fuel gauge driver");
 317 MODULE_LICENSE("GPL");