drivers/hwmon/isl28022.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * isl28022.c - driver for Renesas ISL28022 power monitor chip monitoring
   4  *
   5  * Copyright (c) 2023 Carsten Spieß <mail@carsten-spiess.de>
   6  */
   7
   8 #include <linux/debugfs.h>
   9 #include <linux/err.h>
  10 #include <linux/hwmon.h>
  11 #include <linux/i2c.h>
  12 #include <linux/module.h>
  13 #include <linux/regmap.h>
  14
  15 /* ISL28022 registers */
  16 #define ISL28022_REG_CONFIG     0x00
  17 #define ISL28022_REG_SHUNT      0x01
  18 #define ISL28022_REG_BUS        0x02
  19 #define ISL28022_REG_POWER      0x03
  20 #define ISL28022_REG_CURRENT    0x04
  21 #define ISL28022_REG_CALIB      0x05
  22 #define ISL28022_REG_SHUNT_THR  0x06
  23 #define ISL28022_REG_BUS_THR    0x07
  24 #define ISL28022_REG_INT        0x08
  25 #define ISL28022_REG_AUX        0x09
  26 #define ISL28022_REG_MAX        ISL28022_REG_AUX
  27
  28 /* ISL28022 config flags */
  29 /* mode flags */
  30 #define ISL28022_MODE_SHIFT     0
  31 #define ISL28022_MODE_MASK      0x0007
  32
  33 #define ISL28022_MODE_PWR_DOWN  0x0
  34 #define ISL28022_MODE_TRG_S     0x1
  35 #define ISL28022_MODE_TRG_B     0x2
  36 #define ISL28022_MODE_TRG_SB    0x3
  37 #define ISL28022_MODE_ADC_OFF   0x4
  38 #define ISL28022_MODE_CONT_S    0x5
  39 #define ISL28022_MODE_CONT_B    0x6
  40 #define ISL28022_MODE_CONT_SB   0x7
  41
  42 /* shunt ADC settings */
  43 #define ISL28022_SADC_SHIFT     3
  44 #define ISL28022_SADC_MASK      0x0078
  45
  46 #define ISL28022_BADC_SHIFT     7
  47 #define ISL28022_BADC_MASK      0x0780
  48
  49 #define ISL28022_ADC_12         0x0     /* 12 bit ADC */
  50 #define ISL28022_ADC_13         0x1     /* 13 bit ADC */
  51 #define ISL28022_ADC_14         0x2     /* 14 bit ADC */
  52 #define ISL28022_ADC_15         0x3     /* 15 bit ADC */
  53 #define ISL28022_ADC_15_1       0x8     /* 15 bit ADC, 1 sample */
  54 #define ISL28022_ADC_15_2       0x9     /* 15 bit ADC, 2 samples */
  55 #define ISL28022_ADC_15_4       0xA     /* 15 bit ADC, 4 samples */
  56 #define ISL28022_ADC_15_8       0xB     /* 15 bit ADC, 8 samples */
  57 #define ISL28022_ADC_15_16      0xC     /* 15 bit ADC, 16 samples */
  58 #define ISL28022_ADC_15_32      0xD     /* 15 bit ADC, 32 samples */
  59 #define ISL28022_ADC_15_64      0xE     /* 15 bit ADC, 64 samples */
  60 #define ISL28022_ADC_15_128     0xF     /* 15 bit ADC, 128 samples */
  61
  62 /* shunt voltage range */
  63 #define ISL28022_PG_SHIFT       11
  64 #define ISL28022_PG_MASK        0x1800
  65
  66 #define ISL28022_PG_40          0x0     /* +/-40 mV */
  67 #define ISL28022_PG_80          0x1     /* +/-80 mV */
  68 #define ISL28022_PG_160         0x2     /* +/-160 mV */
  69 #define ISL28022_PG_320         0x3     /* +/-3200 mV */
  70
  71 /* bus voltage range */
  72 #define ISL28022_BRNG_SHIFT     13
  73 #define ISL28022_BRNG_MASK      0x6000
  74
  75 #define ISL28022_BRNG_16        0x0     /* 16 V */
  76 #define ISL28022_BRNG_32        0x1     /* 32 V */
  77 #define ISL28022_BRNG_60        0x3     /* 60 V */
  78
  79 /* reset */
  80 #define ISL28022_RESET          0x8000
  81
  82 struct isl28022_data {
  83         struct regmap           *regmap;
  84         u32                     shunt;
  85         u32                     gain;
  86         u32                     average;
  87 };
  88
  89 static int isl28022_read_in(struct device *dev, u32 attr, int channel, long *val)
  90 {
  91         struct isl28022_data *data = dev_get_drvdata(dev);
  92         unsigned int regval;
  93         int err;
  94         u16 sign_bit;
  95
  96         switch (channel) {
  97         case 0:
  98                 switch (attr) {
  99                 case hwmon_in_input:
 100                         err = regmap_read(data->regmap,
 101                                           ISL28022_REG_BUS, &regval);
 102                         if (err < 0)
 103                                 return err;
 104                         /* driver supports only 60V mode (BRNG 11) */
 105                         *val = (long)(((u16)regval) & 0xFFFC);
 106                         break;
 107                 default:
 108                         return -EOPNOTSUPP;
 109                 }
 110                 break;
 111         case 1:
 112                 switch (attr) {
 113                 case hwmon_in_input:
 114                         err = regmap_read(data->regmap,
 115                                           ISL28022_REG_SHUNT, &regval);
 116                         if (err < 0)
 117                                 return err;
 118                         switch (data->gain) {
 119                         case 8:
 120                                 sign_bit = (regval >> 15) & 0x01;
 121                                 *val = (long)((((u16)regval) & 0x7FFF) -
 122                                         (sign_bit * 32768)) / 100;
 123                                 break;
 124                         case 4:
 125                                 sign_bit = (regval >> 14) & 0x01;
 126                                 *val = (long)((((u16)regval) & 0x3FFF) -
 127                                         (sign_bit * 16384)) / 100;
 128                                 break;
 129                         case 2:
 130                                 sign_bit = (regval >> 13) & 0x01;
 131                                 *val = (long)((((u16)regval) & 0x1FFF) -
 132                                         (sign_bit * 8192)) / 100;
 133                                 break;
 134                         case 1:
 135                                 sign_bit = (regval >> 12) & 0x01;
 136                                 *val = (long)((((u16)regval) & 0x0FFF) -
 137                                         (sign_bit * 4096)) / 100;
 138                                 break;
 139                         }
 140                         break;
 141                 default:
 142                         return -EOPNOTSUPP;
 143                 }
 144                 break;
 145         default:
 146                 return -EOPNOTSUPP;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int isl28022_read_current(struct device *dev, u32 attr, long *val)
 153 {
 154         struct isl28022_data *data = dev_get_drvdata(dev);
 155         unsigned int regval;
 156         int err;
 157
 158         switch (attr) {
 159         case hwmon_curr_input:
 160                 err = regmap_read(data->regmap,
 161                                   ISL28022_REG_CURRENT, &regval);
 162                 if (err < 0)
 163                         return err;
 164                 *val = ((long)regval * 1250L * (long)data->gain) /
 165                         (long)data->shunt;
 166                 break;
 167         default:
 168                 return -EOPNOTSUPP;
 169         }
 170
 171         return 0;
 172 }
 173
 174 static int isl28022_read_power(struct device *dev, u32 attr, long *val)
 175 {
 176         struct isl28022_data *data = dev_get_drvdata(dev);
 177         unsigned int regval;
 178         int err;
 179
 180         switch (attr) {
 181         case hwmon_power_input:
 182                 err = regmap_read(data->regmap,
 183                                   ISL28022_REG_POWER, &regval);
 184                 if (err < 0)
 185                         return err;
 186                 *val = ((51200000L * ((long)data->gain)) /
 187                         (long)data->shunt) * (long)regval;
 188                 break;
 189         default:
 190                 return -EOPNOTSUPP;
 191         }
 192
 193         return 0;
 194 }
 195
 196 static int isl28022_read(struct device *dev, enum hwmon_sensor_types type,
 197                          u32 attr, int channel, long *val)
 198 {
 199         switch (type) {
 200         case hwmon_in:
 201                 return isl28022_read_in(dev, attr, channel, val);
 202         case hwmon_curr:
 203                 return isl28022_read_current(dev, attr, val);
 204         case hwmon_power:
 205                 return isl28022_read_power(dev, attr, val);
 206         default:
 207                 return -EOPNOTSUPP;
 208         }
 209         return 0;
 210 }
 211
 212 static umode_t isl28022_is_visible(const void *data, enum hwmon_sensor_types type,
 213                                    u32 attr, int channel)
 214 {
 215         switch (type) {
 216         case hwmon_in:
 217                 switch (attr) {
 218                 case hwmon_in_input:
 219                         return 0444;
 220                 default:
 221                         break;
 222                 }
 223                 break;
 224         case hwmon_curr:
 225                 switch (attr) {
 226                 case hwmon_curr_input:
 227                         return 0444;
 228                 default:
 229                         break;
 230                 }
 231                 break;
 232         case hwmon_power:
 233                 switch (attr) {
 234                 case hwmon_power_input:
 235                         return 0444;
 236                 default:
 237                         break;
 238                 }
 239                 break;
 240         default:
 241                 break;
 242         }
 243         return 0;
 244 }
 245
 246 static const struct hwmon_channel_info *isl28022_info[] = {
 247         HWMON_CHANNEL_INFO(in,
 248                            HWMON_I_INPUT,       /* channel 0: bus voltage (mV) */
 249                            HWMON_I_INPUT),      /* channel 1: shunt voltage (mV) */
 250         HWMON_CHANNEL_INFO(curr,
 251                            HWMON_C_INPUT),      /* channel 1: current (mA) */
 252         HWMON_CHANNEL_INFO(power,
 253                            HWMON_P_INPUT),      /* channel 1: power (µW) */
 254         NULL
 255 };
 256
 257 static const struct hwmon_ops isl28022_hwmon_ops = {
 258         .is_visible = isl28022_is_visible,
 259         .read = isl28022_read,
 260 };
 261
 262 static const struct hwmon_chip_info isl28022_chip_info = {
 263         .ops = &isl28022_hwmon_ops,
 264         .info = isl28022_info,
 265 };
 266
 267 static bool isl28022_is_writeable_reg(struct device *dev, unsigned int reg)
 268 {
 269         switch (reg) {
 270         case ISL28022_REG_CONFIG:
 271         case ISL28022_REG_CALIB:
 272         case ISL28022_REG_SHUNT_THR:
 273         case ISL28022_REG_BUS_THR:
 274         case ISL28022_REG_INT:
 275         case ISL28022_REG_AUX:
 276                 return true;
 277         }
 278
 279         return false;
 280 }
 281
 282 static bool isl28022_is_volatile_reg(struct device *dev, unsigned int reg)
 283 {
 284         switch (reg) {
 285         case ISL28022_REG_CONFIG:
 286         case ISL28022_REG_SHUNT:
 287         case ISL28022_REG_BUS:
 288         case ISL28022_REG_POWER:
 289         case ISL28022_REG_CURRENT:
 290         case ISL28022_REG_INT:
 291         case ISL28022_REG_AUX:
 292                 return true;
 293         }
 294         return true;
 295 }
 296
 297 static const struct regmap_config isl28022_regmap_config = {
 298         .reg_bits = 8,
 299         .val_bits = 16,
 300         .max_register = ISL28022_REG_MAX,
 301         .writeable_reg = isl28022_is_writeable_reg,
 302         .volatile_reg = isl28022_is_volatile_reg,
 303         .val_format_endian = REGMAP_ENDIAN_BIG,
 304         .cache_type = REGCACHE_RBTREE,
 305         .use_single_read = true,
 306         .use_single_write = true,
 307 };
 308
 309 static int shunt_voltage_show(struct seq_file *seqf, void *unused)
 310 {
 311         struct isl28022_data *data = seqf->private;
 312         unsigned int regval;
 313         int err;
 314
 315         err = regmap_read(data->regmap,
 316                           ISL28022_REG_SHUNT, &regval);
 317         if (err)
 318                 return err;
 319
 320         /* print shunt voltage in micro volt  */
 321         seq_printf(seqf, "%d\n", regval * 10);
 322
 323         return 0;
 324 }
 325 DEFINE_SHOW_ATTRIBUTE(shunt_voltage);
 326
 327 static struct dentry *isl28022_debugfs_root;
 328
 329 static void isl28022_debugfs_remove(void *res)
 330 {
 331         debugfs_remove_recursive(res);
 332 }
 333
 334 static void isl28022_debugfs_init(struct i2c_client *client, struct isl28022_data *data)
 335 {
 336         char name[16];
 337         struct dentry *debugfs;
 338
 339         scnprintf(name, sizeof(name), "%d-%04hx", client->adapter->nr, client->addr);
 340
 341         debugfs = debugfs_create_dir(name, isl28022_debugfs_root);
 342         debugfs_create_file("shunt_voltage", 0444, debugfs, data, &shunt_voltage_fops);
 343
 344         devm_add_action_or_reset(&client->dev, isl28022_debugfs_remove, debugfs);
 345 }
 346
 347 /*
 348  * read property values and make consistency checks.
 349  *
 350  * following values for shunt range and resistor are allowed:
 351  *   40 mV -> gain 1, shunt min.  800 micro ohms
 352  *   80 mV -> gain 2, shunt min. 1600 micro ohms
 353  *  160 mV -> gain 4, shunt min. 3200 micro ohms
 354  *  320 mV -> gain 8, shunt min. 6400 micro ohms
 355  */
 356 static int isl28022_read_properties(struct device *dev, struct isl28022_data *data)
 357 {
 358         u32 val;
 359         int err;
 360
 361         err = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
 362         if (err == -EINVAL)
 363                 val = 10000;
 364         else if (err < 0)
 365                 return err;
 366         data->shunt = val;
 367
 368         err = device_property_read_u32(dev, "renesas,shunt-range-microvolt", &val);
 369         if (err == -EINVAL)
 370                 val = 320000;
 371         else if (err < 0)
 372                 return err;
 373
 374         switch (val) {
 375         case 40000:
 376                 data->gain = 1;
 377                 if (data->shunt < 800)
 378                         goto shunt_invalid;
 379                 break;
 380         case 80000:
 381                 data->gain = 2;
 382                 if (data->shunt < 1600)
 383                         goto shunt_invalid;
 384                 break;
 385         case 160000:
 386                 data->gain = 4;
 387                 if (data->shunt < 3200)
 388                         goto shunt_invalid;
 389                 break;
 390         case 320000:
 391                 data->gain = 8;
 392                 if (data->shunt < 6400)
 393                         goto shunt_invalid;
 394                 break;
 395         default:
 396                 return dev_err_probe(dev, -EINVAL,
 397                                      "renesas,shunt-range-microvolt invalid value %d\n",
 398                                      val);
 399         }
 400
 401         err = device_property_read_u32(dev, "renesas,average-samples", &val);
 402         if (err == -EINVAL)
 403                 val = 1;
 404         else if (err < 0)
 405                 return err;
 406         if (val > 128 || hweight32(val) != 1)
 407                 return dev_err_probe(dev, -EINVAL,
 408                                      "renesas,average-samples invalid value %d\n",
 409                                      val);
 410
 411         data->average = val;
 412
 413         return 0;
 414
 415 shunt_invalid:
 416         return dev_err_probe(dev, -EINVAL,
 417                              "renesas,shunt-resistor-microvolt invalid value %d\n",
 418                              data->shunt);
 419 }
 420
 421 /*
 422  * write configuration and calibration registers
 423  *
 424  * The driver supports only shunt and bus continuous ADC mode at 15bit resolution
 425  * with averaging from 1 to 128 samples (pow of 2) on both channels.
 426  * Shunt voltage gain 1,2,4 or 8 is allowed.
 427  * The bus voltage range is 60V fixed.
 428  */
 429 static int isl28022_config(struct isl28022_data *data)
 430 {
 431         int err;
 432         u16 config;
 433         u16 calib;
 434
 435         config = (ISL28022_MODE_CONT_SB << ISL28022_MODE_SHIFT) |
 436                         (ISL28022_BRNG_60 << ISL28022_BRNG_SHIFT) |
 437                         (__ffs(data->gain) << ISL28022_PG_SHIFT) |
 438                         ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_SADC_SHIFT) |
 439                         ((ISL28022_ADC_15_1 + __ffs(data->average)) << ISL28022_BADC_SHIFT);
 440
 441         calib = data->shunt ? 0x8000 / data->gain : 0;
 442
 443         err = regmap_write(data->regmap, ISL28022_REG_CONFIG, config);
 444         if (err < 0)
 445                 return err;
 446
 447         return regmap_write(data->regmap, ISL28022_REG_CALIB, calib);
 448 }
 449
 450 static int isl28022_probe(struct i2c_client *client)
 451 {
 452         struct device *dev = &client->dev;
 453         struct device *hwmon_dev;
 454         struct isl28022_data *data;
 455         int err;
 456
 457         if (!i2c_check_functionality(client->adapter,
 458                                      I2C_FUNC_SMBUS_BYTE_DATA |
 459                                      I2C_FUNC_SMBUS_WORD_DATA))
 460                 return -ENODEV;
 461
 462         data = devm_kzalloc(dev, sizeof(struct isl28022_data), GFP_KERNEL);
 463         if (!data)
 464                 return -ENOMEM;
 465
 466         err = isl28022_read_properties(dev, data);
 467         if (err)
 468                 return err;
 469
 470         data->regmap = devm_regmap_init_i2c(client, &isl28022_regmap_config);
 471         if (IS_ERR(data->regmap))
 472                 return PTR_ERR(data->regmap);
 473
 474         err = isl28022_config(data);
 475         if (err)
 476                 return err;
 477
 478         isl28022_debugfs_init(client, data);
 479
 480         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 481                                                          data, &isl28022_chip_info, NULL);
 482         if (IS_ERR(hwmon_dev))
 483                 return PTR_ERR(hwmon_dev);
 484
 485         return 0;
 486 }
 487
 488 static const struct i2c_device_id isl28022_ids[] = {
 489         { "isl28022", 0},
 490         { /* LIST END */ }
 491 };
 492 MODULE_DEVICE_TABLE(i2c, isl28022_ids);
 493
 494 static const struct of_device_id __maybe_unused isl28022_of_match[] = {
 495         { .compatible = "renesas,isl28022"},
 496         { /* LIST END */ }
 497 };
 498 MODULE_DEVICE_TABLE(of, isl28022_of_match);
 499
 500 static struct i2c_driver isl28022_driver = {
 501         .class          = I2C_CLASS_HWMON,
 502         .driver = {
 503                 .name   = "isl28022",
 504         },
 505         .probe  = isl28022_probe,
 506         .id_table       = isl28022_ids,
 507 };
 508
 509 static int __init
 510 isl28022_init(void)
 511 {
 512         int err;
 513
 514         isl28022_debugfs_root = debugfs_create_dir("isl28022", NULL);
 515         err = i2c_add_driver(&isl28022_driver);
 516         if (!err)
 517                 return 0;
 518
 519         debugfs_remove_recursive(isl28022_debugfs_root);
 520         return err;
 521 }
 522
 523 static void __exit
 524 isl28022_exit(void)
 525 {
 526         i2c_del_driver(&isl28022_driver);
 527         debugfs_remove_recursive(isl28022_debugfs_root);
 528 }
 529
 530 module_init(isl28022_init);
 531 module_exit(isl28022_exit);
 532
 533 MODULE_AUTHOR("Carsten Spieß <mail@carsten-spiess.de>");
 534 MODULE_DESCRIPTION("ISL28022 driver");
 535 MODULE_LICENSE("GPL");