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