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         __le16 regval;
 144         long raw_val;
 145         int err;
 146
 147         if (channel < TPS23861_NUM_PORTS) {
 148                 err = regmap_bulk_read(data->regmap,
 149                                        PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
 150                                        &regval, 2);
 151         } else {
 152                 err = regmap_bulk_read(data->regmap,
 153                                        INPUT_VOLTAGE_LSB,
 154                                        &regval, 2);
 155         }
 156         if (err < 0)
 157                 return err;
 158
 159         raw_val = le16_to_cpu(regval);
 160         *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * VOLTAGE_LSB) / 1000;
 161
 162         return 0;
 163 }
 164
 165 static int tps23861_read_current(struct tps23861_data *data, int channel,
 166                                  long *val)
 167 {
 168         long raw_val, current_lsb;
 169         __le16 regval;
 170
 171         int err;
 172
 173         if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 174                 current_lsb = CURRENT_LSB_255;
 175         else
 176                 current_lsb = CURRENT_LSB_250;
 177
 178         err = regmap_bulk_read(data->regmap,
 179                                PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
 180                                &regval, 2);
 181         if (err < 0)
 182                 return err;
 183
 184         raw_val = le16_to_cpu(regval);
 185         *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, raw_val) * current_lsb) / 1000000;
 186
 187         return 0;
 188 }
 189
 190 static int tps23861_port_disable(struct tps23861_data *data, int channel)
 191 {
 192         unsigned int regval = 0;
 193         int err;
 194
 195         regval |= BIT(channel + 4);
 196         err = regmap_write(data->regmap, POWER_ENABLE, regval);
 197
 198         return err;
 199 }
 200
 201 static int tps23861_port_enable(struct tps23861_data *data, int channel)
 202 {
 203         unsigned int regval = 0;
 204         int err;
 205
 206         regval |= BIT(channel);
 207         regval |= BIT(channel + 4);
 208         err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);
 209
 210         return err;
 211 }
 212
 213 static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
 214                                    u32 attr, int channel)
 215 {
 216         switch (type) {
 217         case hwmon_temp:
 218                 switch (attr) {
 219                 case hwmon_temp_input:
 220                 case hwmon_temp_label:
 221                         return 0444;
 222                 default:
 223                         return 0;
 224                 }
 225         case hwmon_in:
 226                 switch (attr) {
 227                 case hwmon_in_input:
 228                 case hwmon_in_label:
 229                         return 0444;
 230                 case hwmon_in_enable:
 231                         return 0200;
 232                 default:
 233                         return 0;
 234                 }
 235         case hwmon_curr:
 236                 switch (attr) {
 237                 case hwmon_curr_input:
 238                 case hwmon_curr_label:
 239                         return 0444;
 240                 default:
 241                         return 0;
 242                 }
 243         default:
 244                 return 0;
 245         }
 246 }
 247
 248 static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
 249                           u32 attr, int channel, long val)
 250 {
 251         struct tps23861_data *data = dev_get_drvdata(dev);
 252         int err;
 253
 254         switch (type) {
 255         case hwmon_in:
 256                 switch (attr) {
 257                 case hwmon_in_enable:
 258                         if (val == 0)
 259                                 err = tps23861_port_disable(data, channel);
 260                         else if (val == 1)
 261                                 err = tps23861_port_enable(data, channel);
 262                         else
 263                                 err = -EINVAL;
 264                         break;
 265                 default:
 266                         return -EOPNOTSUPP;
 267                 }
 268                 break;
 269         default:
 270                 return -EOPNOTSUPP;
 271         }
 272
 273         return err;
 274 }
 275
 276 static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
 277                          u32 attr, int channel, long *val)
 278 {
 279         struct tps23861_data *data = dev_get_drvdata(dev);
 280         int err;
 281
 282         switch (type) {
 283         case hwmon_temp:
 284                 switch (attr) {
 285                 case hwmon_temp_input:
 286                         err = tps23861_read_temp(data, val);
 287                         break;
 288                 default:
 289                         return -EOPNOTSUPP;
 290                 }
 291                 break;
 292         case hwmon_in:
 293                 switch (attr) {
 294                 case hwmon_in_input:
 295                         err = tps23861_read_voltage(data, channel, val);
 296                         break;
 297                 default:
 298                         return -EOPNOTSUPP;
 299                 }
 300                 break;
 301         case hwmon_curr:
 302                 switch (attr) {
 303                 case hwmon_curr_input:
 304                         err = tps23861_read_current(data, channel, val);
 305                         break;
 306                 default:
 307                         return -EOPNOTSUPP;
 308                 }
 309                 break;
 310         default:
 311                 return -EOPNOTSUPP;
 312         }
 313
 314         return err;
 315 }
 316
 317 static const char * const tps23861_port_label[] = {
 318         "Port1",
 319         "Port2",
 320         "Port3",
 321         "Port4",
 322         "Input",
 323 };
 324
 325 static int tps23861_read_string(struct device *dev,
 326                                 enum hwmon_sensor_types type,
 327                                 u32 attr, int channel, const char **str)
 328 {
 329         switch (type) {
 330         case hwmon_in:
 331         case hwmon_curr:
 332                 *str = tps23861_port_label[channel];
 333                 break;
 334         case hwmon_temp:
 335                 *str = "Die";
 336                 break;
 337         default:
 338                 return -EOPNOTSUPP;
 339         }
 340
 341         return 0;
 342 }
 343
 344 static const struct hwmon_channel_info * const tps23861_info[] = {
 345         HWMON_CHANNEL_INFO(chip,
 346                            HWMON_C_REGISTER_TZ),
 347         HWMON_CHANNEL_INFO(temp,
 348                            HWMON_T_INPUT | HWMON_T_LABEL),
 349         HWMON_CHANNEL_INFO(in,
 350                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 351                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 352                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 353                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 354                            HWMON_I_INPUT | HWMON_I_LABEL),
 355         HWMON_CHANNEL_INFO(curr,
 356                            HWMON_C_INPUT | HWMON_C_LABEL,
 357                            HWMON_C_INPUT | HWMON_C_LABEL,
 358                            HWMON_C_INPUT | HWMON_C_LABEL,
 359                            HWMON_C_INPUT | HWMON_C_LABEL),
 360         NULL
 361 };
 362
 363 static const struct hwmon_ops tps23861_hwmon_ops = {
 364         .is_visible = tps23861_is_visible,
 365         .write = tps23861_write,
 366         .read = tps23861_read,
 367         .read_string = tps23861_read_string,
 368 };
 369
 370 static const struct hwmon_chip_info tps23861_chip_info = {
 371         .ops = &tps23861_hwmon_ops,
 372         .info = tps23861_info,
 373 };
 374
 375 static char *port_operating_mode_string(uint8_t mode_reg, unsigned int port)
 376 {
 377         unsigned int mode = ~0;
 378
 379         if (port < TPS23861_NUM_PORTS)
 380                 mode = (mode_reg >> (2 * port)) & OPERATING_MODE_PORT_1_MASK;
 381
 382         switch (mode) {
 383         case OPERATING_MODE_OFF:
 384                 return "Off";
 385         case OPERATING_MODE_MANUAL:
 386                 return "Manual";
 387         case OPERATING_MODE_SEMI:
 388                 return "Semi-Auto";
 389         case OPERATING_MODE_AUTO:
 390                 return "Auto";
 391         default:
 392                 return "Invalid";
 393         }
 394 }
 395
 396 static char *port_detect_status_string(uint8_t status_reg)
 397 {
 398         switch (FIELD_GET(PORT_STATUS_DETECT_MASK, status_reg)) {
 399         case PORT_DETECT_UNKNOWN:
 400                 return "Unknown device";
 401         case PORT_DETECT_SHORT:
 402                 return "Short circuit";
 403         case PORT_DETECT_RESISTANCE_LOW:
 404                 return "Too low resistance";
 405         case PORT_DETECT_RESISTANCE_OK:
 406                 return "Valid resistance";
 407         case PORT_DETECT_RESISTANCE_HIGH:
 408                 return "Too high resistance";
 409         case PORT_DETECT_OPEN_CIRCUIT:
 410                 return "Open circuit";
 411         case PORT_DETECT_MOSFET_FAULT:
 412                 return "MOSFET fault";
 413         case PORT_DETECT_LEGACY:
 414                 return "Legacy device";
 415         case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
 416                 return "Invalid capacitance, beyond clamp voltage";
 417         case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
 418                 return "Invalid capacitance, insufficient voltage delta";
 419         case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
 420                 return "Valid capacitance, outside of legacy range";
 421         case PORT_DETECT_RESERVED:
 422         case PORT_DETECT_RESERVED_2:
 423         default:
 424                 return "Invalid";
 425         }
 426 }
 427
 428 static char *port_class_status_string(uint8_t status_reg)
 429 {
 430         switch (FIELD_GET(PORT_STATUS_CLASS_MASK, status_reg)) {
 431         case PORT_CLASS_UNKNOWN:
 432                 return "Unknown";
 433         case PORT_CLASS_RESERVED:
 434         case PORT_CLASS_0:
 435                 return "0";
 436         case PORT_CLASS_1:
 437                 return "1";
 438         case PORT_CLASS_2:
 439                 return "2";
 440         case PORT_CLASS_3:
 441                 return "3";
 442         case PORT_CLASS_4:
 443                 return "4";
 444         case PORT_CLASS_OVERCURRENT:
 445                 return "Overcurrent";
 446         case PORT_CLASS_MISMATCH:
 447                 return "Mismatch";
 448         default:
 449                 return "Invalid";
 450         }
 451 }
 452
 453 static char *port_poe_plus_status_string(uint8_t poe_plus, unsigned int port)
 454 {
 455         return (BIT(port + 4) & poe_plus) ? "Yes" : "No";
 456 }
 457
 458 static int tps23861_port_resistance(struct tps23861_data *data, int port)
 459 {
 460         unsigned int raw_val;
 461         __le16 regval;
 462
 463         regmap_bulk_read(data->regmap,
 464                          PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * port,
 465                          &regval,
 466                          2);
 467
 468         raw_val = le16_to_cpu(regval);
 469         switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, raw_val)) {
 470         case PORT_RESISTANCE_RSN_OTHER:
 471                 return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB) / 10000;
 472         case PORT_RESISTANCE_RSN_LOW:
 473                 return (FIELD_GET(PORT_RESISTANCE_MASK, raw_val) * RESISTANCE_LSB_LOW) / 10000;
 474         case PORT_RESISTANCE_RSN_SHORT:
 475         case PORT_RESISTANCE_RSN_OPEN:
 476         default:
 477                 return 0;
 478         }
 479 }
 480
 481 static int tps23861_port_status_show(struct seq_file *s, void *data)
 482 {
 483         struct tps23861_data *priv = s->private;
 484         unsigned int i, mode, poe_plus, status;
 485
 486         regmap_read(priv->regmap, OPERATING_MODE, &mode);
 487         regmap_read(priv->regmap, POE_PLUS, &poe_plus);
 488
 489         for (i = 0; i < TPS23861_NUM_PORTS; i++) {
 490                 regmap_read(priv->regmap, PORT_1_STATUS + i, &status);
 491
 492                 seq_printf(s, "Port: \t\t%d\n", i + 1);
 493                 seq_printf(s, "Operating mode: %s\n", port_operating_mode_string(mode, i));
 494                 seq_printf(s, "Detected: \t%s\n", port_detect_status_string(status));
 495                 seq_printf(s, "Class: \t\t%s\n", port_class_status_string(status));
 496                 seq_printf(s, "PoE Plus: \t%s\n", port_poe_plus_status_string(poe_plus, i));
 497                 seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
 498                 seq_putc(s, '\n');
 499         }
 500
 501         return 0;
 502 }
 503
 504 DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);
 505
 506 static void tps23861_init_debugfs(struct tps23861_data *data,
 507                                   struct device *hwmon_dev)
 508 {
 509         const char *debugfs_name;
 510
 511         debugfs_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "%s-%s",
 512                                       data->client->name, dev_name(hwmon_dev));
 513         if (!debugfs_name)
 514                 return;
 515
 516         data->debugfs_dir = debugfs_create_dir(debugfs_name, NULL);
 517
 518         debugfs_create_file("port_status",
 519                             0400,
 520                             data->debugfs_dir,
 521                             data,
 522                             &tps23861_port_status_fops);
 523 }
 524
 525 static int tps23861_probe(struct i2c_client *client)
 526 {
 527         struct device *dev = &client->dev;
 528         struct tps23861_data *data;
 529         struct device *hwmon_dev;
 530         u32 shunt_resistor;
 531
 532         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 533         if (!data)
 534                 return -ENOMEM;
 535
 536         data->client = client;
 537         i2c_set_clientdata(client, data);
 538
 539         data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
 540         if (IS_ERR(data->regmap)) {
 541                 dev_err(dev, "failed to allocate register map\n");
 542                 return PTR_ERR(data->regmap);
 543         }
 544
 545         if (!of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor))
 546                 data->shunt_resistor = shunt_resistor;
 547         else
 548                 data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
 549
 550         if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 551                 regmap_clear_bits(data->regmap,
 552                                   TPS23861_GENERAL_MASK_1,
 553                                   TPS23861_CURRENT_SHUNT_MASK);
 554         else
 555                 regmap_set_bits(data->regmap,
 556                                 TPS23861_GENERAL_MASK_1,
 557                                 TPS23861_CURRENT_SHUNT_MASK);
 558
 559         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 560                                                          data, &tps23861_chip_info,
 561                                                          NULL);
 562         if (IS_ERR(hwmon_dev))
 563                 return PTR_ERR(hwmon_dev);
 564
 565         tps23861_init_debugfs(data, hwmon_dev);
 566
 567         return 0;
 568 }
 569
 570 static void tps23861_remove(struct i2c_client *client)
 571 {
 572         struct tps23861_data *data = i2c_get_clientdata(client);
 573
 574         debugfs_remove_recursive(data->debugfs_dir);
 575 }
 576
 577 static const struct of_device_id __maybe_unused tps23861_of_match[] = {
 578         { .compatible = "ti,tps23861", },
 579         { },
 580 };
 581 MODULE_DEVICE_TABLE(of, tps23861_of_match);
 582
 583 static struct i2c_driver tps23861_driver = {
 584         .probe                  = tps23861_probe,
 585         .remove                 = tps23861_remove,
 586         .driver = {
 587                 .name           = "tps23861",
 588                 .of_match_table = of_match_ptr(tps23861_of_match),
 589         },
 590 };
 591 module_i2c_driver(tps23861_driver);
 592
 593 MODULE_LICENSE("GPL");
 594 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
 595 MODULE_DESCRIPTION("TI TPS23861 PoE PSE");