drivers/hwmon/tps23861.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2020 Sartura Ltd.
   4  *
   5  * Driver for the TI TPS23861 PoE PSE.
   6  *
   7  * Author: Robert Marko <robert.marko@sartura.hr>
   8  */
   9
  10 #include <linux/bitfield.h>
  11 #include <linux/debugfs.h>
  12 #include <linux/delay.h>
  13 #include <linux/hwmon-sysfs.h>
  14 #include <linux/hwmon.h>
  15 #include <linux/i2c.h>
  16 #include <linux/module.h>
  17 #include <linux/of_device.h>
  18 #include <linux/regmap.h>
  19
  20 #define TEMPERATURE                     0x2c
  21 #define INPUT_VOLTAGE_LSB               0x2e
  22 #define INPUT_VOLTAGE_MSB               0x2f
  23 #define PORT_1_CURRENT_LSB              0x30
  24 #define PORT_1_CURRENT_MSB              0x31
  25 #define PORT_1_VOLTAGE_LSB              0x32
  26 #define PORT_1_VOLTAGE_MSB              0x33
  27 #define PORT_2_CURRENT_LSB              0x34
  28 #define PORT_2_CURRENT_MSB              0x35
  29 #define PORT_2_VOLTAGE_LSB              0x36
  30 #define PORT_2_VOLTAGE_MSB              0x37
  31 #define PORT_3_CURRENT_LSB              0x38
  32 #define PORT_3_CURRENT_MSB              0x39
  33 #define PORT_3_VOLTAGE_LSB              0x3a
  34 #define PORT_3_VOLTAGE_MSB              0x3b
  35 #define PORT_4_CURRENT_LSB              0x3c
  36 #define PORT_4_CURRENT_MSB              0x3d
  37 #define PORT_4_VOLTAGE_LSB              0x3e
  38 #define PORT_4_VOLTAGE_MSB              0x3f
  39 #define PORT_N_CURRENT_LSB_OFFSET       0x04
  40 #define PORT_N_VOLTAGE_LSB_OFFSET       0x04
  41 #define VOLTAGE_CURRENT_MASK            GENMASK(13, 0)
  42 #define PORT_1_RESISTANCE_LSB           0x60
  43 #define PORT_1_RESISTANCE_MSB           0x61
  44 #define PORT_2_RESISTANCE_LSB           0x62
  45 #define PORT_2_RESISTANCE_MSB           0x63
  46 #define PORT_3_RESISTANCE_LSB           0x64
  47 #define PORT_3_RESISTANCE_MSB           0x65
  48 #define PORT_4_RESISTANCE_LSB           0x66
  49 #define PORT_4_RESISTANCE_MSB           0x67
  50 #define PORT_N_RESISTANCE_LSB_OFFSET    0x02
  51 #define PORT_RESISTANCE_MASK            GENMASK(13, 0)
  52 #define PORT_RESISTANCE_RSN_MASK        GENMASK(15, 14)
  53 #define PORT_RESISTANCE_RSN_OTHER       0
  54 #define PORT_RESISTANCE_RSN_LOW         1
  55 #define PORT_RESISTANCE_RSN_OPEN        2
  56 #define PORT_RESISTANCE_RSN_SHORT       3
  57 #define PORT_1_STATUS                   0x0c
  58 #define PORT_2_STATUS                   0x0d
  59 #define PORT_3_STATUS                   0x0e
  60 #define PORT_4_STATUS                   0x0f
  61 #define PORT_STATUS_CLASS_MASK          GENMASK(7, 4)
  62 #define PORT_STATUS_DETECT_MASK         GENMASK(3, 0)
  63 #define PORT_CLASS_UNKNOWN              0
  64 #define PORT_CLASS_1                    1
  65 #define PORT_CLASS_2                    2
  66 #define PORT_CLASS_3                    3
  67 #define PORT_CLASS_4                    4
  68 #define PORT_CLASS_RESERVED             5
  69 #define PORT_CLASS_0                    6
  70 #define PORT_CLASS_OVERCURRENT          7
  71 #define PORT_CLASS_MISMATCH             8
  72 #define PORT_DETECT_UNKNOWN             0
  73 #define PORT_DETECT_SHORT               1
  74 #define PORT_DETECT_RESERVED            2
  75 #define PORT_DETECT_RESISTANCE_LOW      3
  76 #define PORT_DETECT_RESISTANCE_OK       4
  77 #define PORT_DETECT_RESISTANCE_HIGH     5
  78 #define PORT_DETECT_OPEN_CIRCUIT        6
  79 #define PORT_DETECT_RESERVED_2          7
  80 #define PORT_DETECT_MOSFET_FAULT        8
  81 #define PORT_DETECT_LEGACY              9
  82 /* Measurment beyond clamp voltage */
  83 #define PORT_DETECT_CAPACITANCE_INVALID_BEYOND  10
  84 /* Insufficient voltage delta */
  85 #define PORT_DETECT_CAPACITANCE_INVALID_DELTA   11
  86 #define PORT_DETECT_CAPACITANCE_OUT_OF_RANGE    12
  87 #define POE_PLUS                        0x40
  88 #define OPERATING_MODE                  0x12
  89 #define OPERATING_MODE_OFF              0
  90 #define OPERATING_MODE_MANUAL           1
  91 #define OPERATING_MODE_SEMI             2
  92 #define OPERATING_MODE_AUTO             3
  93 #define OPERATING_MODE_PORT_1_MASK      GENMASK(1, 0)
  94 #define OPERATING_MODE_PORT_2_MASK      GENMASK(3, 2)
  95 #define OPERATING_MODE_PORT_3_MASK      GENMASK(5, 4)
  96 #define OPERATING_MODE_PORT_4_MASK      GENMASK(7, 6)
  97
  98 #define DETECT_CLASS_RESTART            0x18
  99 #define POWER_ENABLE                    0x19
 100 #define TPS23861_NUM_PORTS              4
 101
 102 #define TPS23861_GENERAL_MASK_1         0x17
 103 #define TPS23861_CURRENT_SHUNT_MASK     BIT(0)
 104
 105 #define TEMPERATURE_LSB                 652 /* 0.652 degrees Celsius */
 106 #define VOLTAGE_LSB                     3662 /* 3.662 mV */
 107 #define SHUNT_RESISTOR_DEFAULT          255000 /* 255 mOhm */
 108 #define CURRENT_LSB_250                 62260 /* 62.260 uA */
 109 #define CURRENT_LSB_255                 61039 /* 61.039 uA */
 110 #define RESISTANCE_LSB                  110966 /* 11.0966 Ohm*/
 111 #define RESISTANCE_LSB_LOW              157216 /* 15.7216 Ohm*/
 112
 113 struct tps23861_data {
 114         struct regmap *regmap;
 115         u32 shunt_resistor;
 116         struct i2c_client *client;
 117         struct dentry *debugfs_dir;
 118 };
 119
 120 static struct regmap_config tps23861_regmap_config = {
 121         .reg_bits = 8,
 122         .val_bits = 8,
 123         .max_register = 0x6f,
 124 };
 125
 126 static int tps23861_read_temp(struct tps23861_data *data, long *val)
 127 {
 128         unsigned int regval;
 129         int err;
 130
 131         err = regmap_read(data->regmap, TEMPERATURE, &regval);
 132         if (err < 0)
 133                 return err;
 134
 135         *val = (regval * TEMPERATURE_LSB) - 20000;
 136
 137         return 0;
 138 }
 139
 140 static int tps23861_read_voltage(struct tps23861_data *data, int channel,
 141                                  long *val)
 142 {
 143         unsigned int regval;
 144         int err;
 145
 146         if (channel < TPS23861_NUM_PORTS) {
 147                 err = regmap_bulk_read(data->regmap,
 148                                        PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
 149                                        &regval, 2);
 150         } else {
 151                 err = regmap_bulk_read(data->regmap,
 152                                        INPUT_VOLTAGE_LSB,
 153                                        &regval, 2);
 154         }
 155         if (err < 0)
 156                 return err;
 157
 158         *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
 159
 160         return 0;
 161 }
 162
 163 static int tps23861_read_current(struct tps23861_data *data, int channel,
 164                                  long *val)
 165 {
 166         unsigned int current_lsb;
 167         unsigned int regval;
 168         int err;
 169
 170         if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 171                 current_lsb = CURRENT_LSB_255;
 172         else
 173                 current_lsb = CURRENT_LSB_250;
 174
 175         err = regmap_bulk_read(data->regmap,
 176                                PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
 177                                &regval, 2);
 178         if (err < 0)
 179                 return err;
 180
 181         *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
 182
 183         return 0;
 184 }
 185
 186 static int tps23861_port_disable(struct tps23861_data *data, int channel)
 187 {
 188         unsigned int regval = 0;
 189         int err;
 190
 191         regval |= BIT(channel + 4);
 192         err = regmap_write(data->regmap, POWER_ENABLE, regval);
 193
 194         return err;
 195 }
 196
 197 static int tps23861_port_enable(struct tps23861_data *data, int channel)
 198 {
 199         unsigned int regval = 0;
 200         int err;
 201
 202         regval |= BIT(channel);
 203         regval |= BIT(channel + 4);
 204         err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);
 205
 206         return err;
 207 }
 208
 209 static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
 210                                    u32 attr, int channel)
 211 {
 212         switch (type) {
 213         case hwmon_temp:
 214                 switch (attr) {
 215                 case hwmon_temp_input:
 216                 case hwmon_temp_label:
 217                         return 0444;
 218                 default:
 219                         return 0;
 220                 }
 221         case hwmon_in:
 222                 switch (attr) {
 223                 case hwmon_in_input:
 224                 case hwmon_in_label:
 225                         return 0444;
 226                 case hwmon_in_enable:
 227                         return 0200;
 228                 default:
 229                         return 0;
 230                 }
 231         case hwmon_curr:
 232                 switch (attr) {
 233                 case hwmon_curr_input:
 234                 case hwmon_curr_label:
 235                         return 0444;
 236                 default:
 237                         return 0;
 238                 }
 239         default:
 240                 return 0;
 241         }
 242 }
 243
 244 static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
 245                           u32 attr, int channel, long val)
 246 {
 247         struct tps23861_data *data = dev_get_drvdata(dev);
 248         int err;
 249
 250         switch (type) {
 251         case hwmon_in:
 252                 switch (attr) {
 253                 case hwmon_in_enable:
 254                         if (val == 0)
 255                                 err = tps23861_port_disable(data, channel);
 256                         else if (val == 1)
 257                                 err = tps23861_port_enable(data, channel);
 258                         else
 259                                 err = -EINVAL;
 260                         break;
 261                 default:
 262                         return -EOPNOTSUPP;
 263                 }
 264                 break;
 265         default:
 266                 return -EOPNOTSUPP;
 267         }
 268
 269         return err;
 270 }
 271
 272 static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
 273                          u32 attr, int channel, long *val)
 274 {
 275         struct tps23861_data *data = dev_get_drvdata(dev);
 276         int err;
 277
 278         switch (type) {
 279         case hwmon_temp:
 280                 switch (attr) {
 281                 case hwmon_temp_input:
 282                         err = tps23861_read_temp(data, val);
 283                         break;
 284                 default:
 285                         return -EOPNOTSUPP;
 286                 }
 287                 break;
 288         case hwmon_in:
 289                 switch (attr) {
 290                 case hwmon_in_input:
 291                         err = tps23861_read_voltage(data, channel, val);
 292                         break;
 293                 default:
 294                         return -EOPNOTSUPP;
 295                 }
 296                 break;
 297         case hwmon_curr:
 298                 switch (attr) {
 299                 case hwmon_curr_input:
 300                         err = tps23861_read_current(data, channel, val);
 301                         break;
 302                 default:
 303                         return -EOPNOTSUPP;
 304                 }
 305                 break;
 306         default:
 307                 return -EOPNOTSUPP;
 308         }
 309
 310         return err;
 311 }
 312
 313 static const char * const tps23861_port_label[] = {
 314         "Port1",
 315         "Port2",
 316         "Port3",
 317         "Port4",
 318         "Input",
 319 };
 320
 321 static int tps23861_read_string(struct device *dev,
 322                                 enum hwmon_sensor_types type,
 323                                 u32 attr, int channel, const char **str)
 324 {
 325         switch (type) {
 326         case hwmon_in:
 327         case hwmon_curr:
 328                 *str = tps23861_port_label[channel];
 329                 break;
 330         case hwmon_temp:
 331                 *str = "Die";
 332                 break;
 333         default:
 334                 return -EOPNOTSUPP;
 335         }
 336
 337         return 0;
 338 }
 339
 340 static const struct hwmon_channel_info *tps23861_info[] = {
 341         HWMON_CHANNEL_INFO(chip,
 342                            HWMON_C_REGISTER_TZ),
 343         HWMON_CHANNEL_INFO(temp,
 344                            HWMON_T_INPUT | HWMON_T_LABEL),
 345         HWMON_CHANNEL_INFO(in,
 346                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 347                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 348                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 349                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 350                            HWMON_I_INPUT | HWMON_I_LABEL),
 351         HWMON_CHANNEL_INFO(curr,
 352                            HWMON_C_INPUT | HWMON_C_LABEL,
 353                            HWMON_C_INPUT | HWMON_C_LABEL,
 354                            HWMON_C_INPUT | HWMON_C_LABEL,
 355                            HWMON_C_INPUT | HWMON_C_LABEL),
 356         NULL
 357 };
 358
 359 static const struct hwmon_ops tps23861_hwmon_ops = {
 360         .is_visible = tps23861_is_visible,
 361         .write = tps23861_write,
 362         .read = tps23861_read,
 363         .read_string = tps23861_read_string,
 364 };
 365
 366 static const struct hwmon_chip_info tps23861_chip_info = {
 367         .ops = &tps23861_hwmon_ops,
 368         .info = tps23861_info,
 369 };
 370
 371 static char *tps23861_port_operating_mode(struct tps23861_data *data, int port)
 372 {
 373         unsigned int regval;
 374         int mode;
 375
 376         regmap_read(data->regmap, OPERATING_MODE, &regval);
 377
 378         switch (port) {
 379         case 1:
 380                 mode = FIELD_GET(OPERATING_MODE_PORT_1_MASK, regval);
 381                 break;
 382         case 2:
 383                 mode = FIELD_GET(OPERATING_MODE_PORT_2_MASK, regval);
 384                 break;
 385         case 3:
 386                 mode = FIELD_GET(OPERATING_MODE_PORT_3_MASK, regval);
 387                 break;
 388         case 4:
 389                 mode = FIELD_GET(OPERATING_MODE_PORT_4_MASK, regval);
 390                 break;
 391         default:
 392                 mode = -EINVAL;
 393         }
 394
 395         switch (mode) {
 396         case OPERATING_MODE_OFF:
 397                 return "Off";
 398         case OPERATING_MODE_MANUAL:
 399                 return "Manual";
 400         case OPERATING_MODE_SEMI:
 401                 return "Semi-Auto";
 402         case OPERATING_MODE_AUTO:
 403                 return "Auto";
 404         default:
 405                 return "Invalid";
 406         }
 407 }
 408
 409 static char *tps23861_port_detect_status(struct tps23861_data *data, int port)
 410 {
 411         unsigned int regval;
 412
 413         regmap_read(data->regmap,
 414                     PORT_1_STATUS + (port - 1),
 415                     &regval);
 416
 417         switch (FIELD_GET(PORT_STATUS_DETECT_MASK, regval)) {
 418         case PORT_DETECT_UNKNOWN:
 419                 return "Unknown device";
 420         case PORT_DETECT_SHORT:
 421                 return "Short circuit";
 422         case PORT_DETECT_RESISTANCE_LOW:
 423                 return "Too low resistance";
 424         case PORT_DETECT_RESISTANCE_OK:
 425                 return "Valid resistance";
 426         case PORT_DETECT_RESISTANCE_HIGH:
 427                 return "Too high resistance";
 428         case PORT_DETECT_OPEN_CIRCUIT:
 429                 return "Open circuit";
 430         case PORT_DETECT_MOSFET_FAULT:
 431                 return "MOSFET fault";
 432         case PORT_DETECT_LEGACY:
 433                 return "Legacy device";
 434         case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
 435                 return "Invalid capacitance, beyond clamp voltage";
 436         case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
 437                 return "Invalid capacitance, insufficient voltage delta";
 438         case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
 439                 return "Valid capacitance, outside of legacy range";
 440         case PORT_DETECT_RESERVED:
 441         case PORT_DETECT_RESERVED_2:
 442         default:
 443                 return "Invalid";
 444         }
 445 }
 446
 447 static char *tps23861_port_class_status(struct tps23861_data *data, int port)
 448 {
 449         unsigned int regval;
 450
 451         regmap_read(data->regmap,
 452                     PORT_1_STATUS + (port - 1),
 453                     &regval);
 454
 455         switch (FIELD_GET(PORT_STATUS_CLASS_MASK, regval)) {
 456         case PORT_CLASS_UNKNOWN:
 457                 return "Unknown";
 458         case PORT_CLASS_RESERVED:
 459         case PORT_CLASS_0:
 460                 return "0";
 461         case PORT_CLASS_1:
 462                 return "1";
 463         case PORT_CLASS_2:
 464                 return "2";
 465         case PORT_CLASS_3:
 466                 return "3";
 467         case PORT_CLASS_4:
 468                 return "4";
 469         case PORT_CLASS_OVERCURRENT:
 470                 return "Overcurrent";
 471         case PORT_CLASS_MISMATCH:
 472                 return "Mismatch";
 473         default:
 474                 return "Invalid";
 475         }
 476 }
 477
 478 static char *tps23861_port_poe_plus_status(struct tps23861_data *data, int port)
 479 {
 480         unsigned int regval;
 481
 482         regmap_read(data->regmap, POE_PLUS, &regval);
 483
 484         if (BIT(port + 3) & regval)
 485                 return "Yes";
 486         else
 487                 return "No";
 488 }
 489
 490 static int tps23861_port_resistance(struct tps23861_data *data, int port)
 491 {
 492         u16 regval;
 493
 494         regmap_bulk_read(data->regmap,
 495                          PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * (port - 1),
 496                          &regval,
 497                          2);
 498
 499         switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, regval)) {
 500         case PORT_RESISTANCE_RSN_OTHER:
 501                 return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB) / 10000;
 502         case PORT_RESISTANCE_RSN_LOW:
 503                 return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB_LOW) / 10000;
 504         case PORT_RESISTANCE_RSN_SHORT:
 505         case PORT_RESISTANCE_RSN_OPEN:
 506         default:
 507                 return 0;
 508         }
 509 }
 510
 511 static int tps23861_port_status_show(struct seq_file *s, void *data)
 512 {
 513         struct tps23861_data *priv = s->private;
 514         int i;
 515
 516         for (i = 1; i < TPS23861_NUM_PORTS + 1; i++) {
 517                 seq_printf(s, "Port: \t\t%d\n", i);
 518                 seq_printf(s, "Operating mode: %s\n", tps23861_port_operating_mode(priv, i));
 519                 seq_printf(s, "Detected: \t%s\n", tps23861_port_detect_status(priv, i));
 520                 seq_printf(s, "Class: \t\t%s\n", tps23861_port_class_status(priv, i));
 521                 seq_printf(s, "PoE Plus: \t%s\n", tps23861_port_poe_plus_status(priv, i));
 522                 seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
 523                 seq_putc(s, '\n');
 524         }
 525
 526         return 0;
 527 }
 528
 529 DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);
 530
 531 static void tps23861_init_debugfs(struct tps23861_data *data)
 532 {
 533         data->debugfs_dir = debugfs_create_dir(data->client->name, NULL);
 534
 535         debugfs_create_file("port_status",
 536                             0400,
 537                             data->debugfs_dir,
 538                             data,
 539                             &tps23861_port_status_fops);
 540 }
 541
 542 static int tps23861_probe(struct i2c_client *client)
 543 {
 544         struct device *dev = &client->dev;
 545         struct tps23861_data *data;
 546         struct device *hwmon_dev;
 547         u32 shunt_resistor;
 548
 549         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 550         if (!data)
 551                 return -ENOMEM;
 552
 553         data->client = client;
 554         i2c_set_clientdata(client, data);
 555
 556         data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
 557         if (IS_ERR(data->regmap)) {
 558                 dev_err(dev, "failed to allocate register map\n");
 559                 return PTR_ERR(data->regmap);
 560         }
 561
 562         if (!of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor))
 563                 data->shunt_resistor = shunt_resistor;
 564         else
 565                 data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
 566
 567         if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 568                 regmap_clear_bits(data->regmap,
 569                                   TPS23861_GENERAL_MASK_1,
 570                                   TPS23861_CURRENT_SHUNT_MASK);
 571         else
 572                 regmap_set_bits(data->regmap,
 573                                 TPS23861_GENERAL_MASK_1,
 574                                 TPS23861_CURRENT_SHUNT_MASK);
 575
 576         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 577                                                          data, &tps23861_chip_info,
 578                                                          NULL);
 579         if (IS_ERR(hwmon_dev))
 580                 return PTR_ERR(hwmon_dev);
 581
 582         tps23861_init_debugfs(data);
 583
 584         return 0;
 585 }
 586
 587 static int tps23861_remove(struct i2c_client *client)
 588 {
 589         struct tps23861_data *data = i2c_get_clientdata(client);
 590
 591         debugfs_remove_recursive(data->debugfs_dir);
 592
 593         return 0;
 594 }
 595
 596 static const struct of_device_id __maybe_unused tps23861_of_match[] = {
 597         { .compatible = "ti,tps23861", },
 598         { },
 599 };
 600 MODULE_DEVICE_TABLE(of, tps23861_of_match);
 601
 602 static struct i2c_driver tps23861_driver = {
 603         .probe_new              = tps23861_probe,
 604         .remove                 = tps23861_remove,
 605         .driver = {
 606                 .name           = "tps23861",
 607                 .of_match_table = of_match_ptr(tps23861_of_match),
 608         },
 609 };
 610 module_i2c_driver(tps23861_driver);
 611
 612 MODULE_LICENSE("GPL");
 613 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
 614 MODULE_DESCRIPTION("TI TPS23861 PoE PSE");