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         .max_register = 0x6f,
 121 };
 122
 123 static int tps23861_read_temp(struct tps23861_data *data, long *val)
 124 {
 125         unsigned int regval;
 126         int err;
 127
 128         err = regmap_read(data->regmap, TEMPERATURE, &regval);
 129         if (err < 0)
 130                 return err;
 131
 132         *val = (regval * TEMPERATURE_LSB) - 20000;
 133
 134         return 0;
 135 }
 136
 137 static int tps23861_read_voltage(struct tps23861_data *data, int channel,
 138                                  long *val)
 139 {
 140         unsigned int regval;
 141         int err;
 142
 143         if (channel < TPS23861_NUM_PORTS) {
 144                 err = regmap_bulk_read(data->regmap,
 145                                        PORT_1_VOLTAGE_LSB + channel * PORT_N_VOLTAGE_LSB_OFFSET,
 146                                        &regval, 2);
 147         } else {
 148                 err = regmap_bulk_read(data->regmap,
 149                                        INPUT_VOLTAGE_LSB,
 150                                        &regval, 2);
 151         }
 152         if (err < 0)
 153                 return err;
 154
 155         *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * VOLTAGE_LSB) / 1000;
 156
 157         return 0;
 158 }
 159
 160 static int tps23861_read_current(struct tps23861_data *data, int channel,
 161                                  long *val)
 162 {
 163         unsigned int current_lsb;
 164         unsigned int regval;
 165         int err;
 166
 167         if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
 168                 current_lsb = CURRENT_LSB_255;
 169         else
 170                 current_lsb = CURRENT_LSB_250;
 171
 172         err = regmap_bulk_read(data->regmap,
 173                                PORT_1_CURRENT_LSB + channel * PORT_N_CURRENT_LSB_OFFSET,
 174                                &regval, 2);
 175         if (err < 0)
 176                 return err;
 177
 178         *val = (FIELD_GET(VOLTAGE_CURRENT_MASK, regval) * current_lsb) / 1000000;
 179
 180         return 0;
 181 }
 182
 183 static int tps23861_port_disable(struct tps23861_data *data, int channel)
 184 {
 185         unsigned int regval = 0;
 186         int err;
 187
 188         regval |= BIT(channel + 4);
 189         err = regmap_write(data->regmap, POWER_ENABLE, regval);
 190
 191         return err;
 192 }
 193
 194 static int tps23861_port_enable(struct tps23861_data *data, int channel)
 195 {
 196         unsigned int regval = 0;
 197         int err;
 198
 199         regval |= BIT(channel);
 200         regval |= BIT(channel + 4);
 201         err = regmap_write(data->regmap, DETECT_CLASS_RESTART, regval);
 202
 203         return err;
 204 }
 205
 206 static umode_t tps23861_is_visible(const void *data, enum hwmon_sensor_types type,
 207                                    u32 attr, int channel)
 208 {
 209         switch (type) {
 210         case hwmon_temp:
 211                 switch (attr) {
 212                 case hwmon_temp_input:
 213                 case hwmon_temp_label:
 214                         return 0444;
 215                 default:
 216                         return 0;
 217                 }
 218         case hwmon_in:
 219                 switch (attr) {
 220                 case hwmon_in_input:
 221                 case hwmon_in_label:
 222                         return 0444;
 223                 case hwmon_in_enable:
 224                         return 0200;
 225                 default:
 226                         return 0;
 227                 }
 228         case hwmon_curr:
 229                 switch (attr) {
 230                 case hwmon_curr_input:
 231                 case hwmon_curr_label:
 232                         return 0444;
 233                 default:
 234                         return 0;
 235                 }
 236         default:
 237                 return 0;
 238         }
 239 }
 240
 241 static int tps23861_write(struct device *dev, enum hwmon_sensor_types type,
 242                           u32 attr, int channel, long val)
 243 {
 244         struct tps23861_data *data = dev_get_drvdata(dev);
 245         int err;
 246
 247         switch (type) {
 248         case hwmon_in:
 249                 switch (attr) {
 250                 case hwmon_in_enable:
 251                         if (val == 0)
 252                                 err = tps23861_port_disable(data, channel);
 253                         else if (val == 1)
 254                                 err = tps23861_port_enable(data, channel);
 255                         else
 256                                 err = -EINVAL;
 257                         break;
 258                 default:
 259                         return -EOPNOTSUPP;
 260                 }
 261                 break;
 262         default:
 263                 return -EOPNOTSUPP;
 264         }
 265
 266         return err;
 267 }
 268
 269 static int tps23861_read(struct device *dev, enum hwmon_sensor_types type,
 270                          u32 attr, int channel, long *val)
 271 {
 272         struct tps23861_data *data = dev_get_drvdata(dev);
 273         int err;
 274
 275         switch (type) {
 276         case hwmon_temp:
 277                 switch (attr) {
 278                 case hwmon_temp_input:
 279                         err = tps23861_read_temp(data, val);
 280                         break;
 281                 default:
 282                         return -EOPNOTSUPP;
 283                 }
 284                 break;
 285         case hwmon_in:
 286                 switch (attr) {
 287                 case hwmon_in_input:
 288                         err = tps23861_read_voltage(data, channel, val);
 289                         break;
 290                 default:
 291                         return -EOPNOTSUPP;
 292                 }
 293                 break;
 294         case hwmon_curr:
 295                 switch (attr) {
 296                 case hwmon_curr_input:
 297                         err = tps23861_read_current(data, channel, val);
 298                         break;
 299                 default:
 300                         return -EOPNOTSUPP;
 301                 }
 302                 break;
 303         default:
 304                 return -EOPNOTSUPP;
 305         }
 306
 307         return err;
 308 }
 309
 310 static const char * const tps23861_port_label[] = {
 311         "Port1",
 312         "Port2",
 313         "Port3",
 314         "Port4",
 315         "Input",
 316 };
 317
 318 static int tps23861_read_string(struct device *dev,
 319                                 enum hwmon_sensor_types type,
 320                                 u32 attr, int channel, const char **str)
 321 {
 322         switch (type) {
 323         case hwmon_in:
 324         case hwmon_curr:
 325                 *str = tps23861_port_label[channel];
 326                 break;
 327         case hwmon_temp:
 328                 *str = "Die";
 329                 break;
 330         default:
 331                 return -EOPNOTSUPP;
 332         }
 333
 334         return 0;
 335 }
 336
 337 static const struct hwmon_channel_info *tps23861_info[] = {
 338         HWMON_CHANNEL_INFO(chip,
 339                            HWMON_C_REGISTER_TZ),
 340         HWMON_CHANNEL_INFO(temp,
 341                            HWMON_T_INPUT | HWMON_T_LABEL),
 342         HWMON_CHANNEL_INFO(in,
 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_ENABLE | HWMON_I_LABEL,
 347                            HWMON_I_INPUT | HWMON_I_LABEL),
 348         HWMON_CHANNEL_INFO(curr,
 349                            HWMON_C_INPUT | HWMON_C_LABEL,
 350                            HWMON_C_INPUT | HWMON_C_LABEL,
 351                            HWMON_C_INPUT | HWMON_C_LABEL,
 352                            HWMON_C_INPUT | HWMON_C_LABEL),
 353         NULL
 354 };
 355
 356 static const struct hwmon_ops tps23861_hwmon_ops = {
 357         .is_visible = tps23861_is_visible,
 358         .write = tps23861_write,
 359         .read = tps23861_read,
 360         .read_string = tps23861_read_string,
 361 };
 362
 363 static const struct hwmon_chip_info tps23861_chip_info = {
 364         .ops = &tps23861_hwmon_ops,
 365         .info = tps23861_info,
 366 };
 367
 368 static char *tps23861_port_operating_mode(struct tps23861_data *data, int port)
 369 {
 370         unsigned int regval;
 371         int mode;
 372
 373         regmap_read(data->regmap, OPERATING_MODE, &regval);
 374
 375         switch (port) {
 376         case 1:
 377                 mode = FIELD_GET(OPERATING_MODE_PORT_1_MASK, regval);
 378                 break;
 379         case 2:
 380                 mode = FIELD_GET(OPERATING_MODE_PORT_2_MASK, regval);
 381                 break;
 382         case 3:
 383                 mode = FIELD_GET(OPERATING_MODE_PORT_3_MASK, regval);
 384                 break;
 385         case 4:
 386                 mode = FIELD_GET(OPERATING_MODE_PORT_4_MASK, regval);
 387                 break;
 388         default:
 389                 mode = -EINVAL;
 390         }
 391
 392         switch (mode) {
 393         case OPERATING_MODE_OFF:
 394                 return "Off";
 395         case OPERATING_MODE_MANUAL:
 396                 return "Manual";
 397         case OPERATING_MODE_SEMI:
 398                 return "Semi-Auto";
 399         case OPERATING_MODE_AUTO:
 400                 return "Auto";
 401         default:
 402                 return "Invalid";
 403         }
 404 }
 405
 406 static char *tps23861_port_detect_status(struct tps23861_data *data, int port)
 407 {
 408         unsigned int regval;
 409
 410         regmap_read(data->regmap,
 411                     PORT_1_STATUS + (port - 1),
 412                     &regval);
 413
 414         switch (FIELD_GET(PORT_STATUS_DETECT_MASK, regval)) {
 415         case PORT_DETECT_UNKNOWN:
 416                 return "Unknown device";
 417         case PORT_DETECT_SHORT:
 418                 return "Short circuit";
 419         case PORT_DETECT_RESISTANCE_LOW:
 420                 return "Too low resistance";
 421         case PORT_DETECT_RESISTANCE_OK:
 422                 return "Valid resistance";
 423         case PORT_DETECT_RESISTANCE_HIGH:
 424                 return "Too high resistance";
 425         case PORT_DETECT_OPEN_CIRCUIT:
 426                 return "Open circuit";
 427         case PORT_DETECT_MOSFET_FAULT:
 428                 return "MOSFET fault";
 429         case PORT_DETECT_LEGACY:
 430                 return "Legacy device";
 431         case PORT_DETECT_CAPACITANCE_INVALID_BEYOND:
 432                 return "Invalid capacitance, beyond clamp voltage";
 433         case PORT_DETECT_CAPACITANCE_INVALID_DELTA:
 434                 return "Invalid capacitance, insufficient voltage delta";
 435         case PORT_DETECT_CAPACITANCE_OUT_OF_RANGE:
 436                 return "Valid capacitance, outside of legacy range";
 437         case PORT_DETECT_RESERVED:
 438         case PORT_DETECT_RESERVED_2:
 439         default:
 440                 return "Invalid";
 441         }
 442 }
 443
 444 static char *tps23861_port_class_status(struct tps23861_data *data, int port)
 445 {
 446         unsigned int regval;
 447
 448         regmap_read(data->regmap,
 449                     PORT_1_STATUS + (port - 1),
 450                     &regval);
 451
 452         switch (FIELD_GET(PORT_STATUS_CLASS_MASK, regval)) {
 453         case PORT_CLASS_UNKNOWN:
 454                 return "Unknown";
 455         case PORT_CLASS_RESERVED:
 456         case PORT_CLASS_0:
 457                 return "0";
 458         case PORT_CLASS_1:
 459                 return "1";
 460         case PORT_CLASS_2:
 461                 return "2";
 462         case PORT_CLASS_3:
 463                 return "3";
 464         case PORT_CLASS_4:
 465                 return "4";
 466         case PORT_CLASS_OVERCURRENT:
 467                 return "Overcurrent";
 468         case PORT_CLASS_MISMATCH:
 469                 return "Mismatch";
 470         default:
 471                 return "Invalid";
 472         }
 473 }
 474
 475 static char *tps23861_port_poe_plus_status(struct tps23861_data *data, int port)
 476 {
 477         unsigned int regval;
 478
 479         regmap_read(data->regmap, POE_PLUS, &regval);
 480
 481         if (BIT(port + 3) & regval)
 482                 return "Yes";
 483         else
 484                 return "No";
 485 }
 486
 487 static int tps23861_port_resistance(struct tps23861_data *data, int port)
 488 {
 489         u16 regval;
 490
 491         regmap_bulk_read(data->regmap,
 492                          PORT_1_RESISTANCE_LSB + PORT_N_RESISTANCE_LSB_OFFSET * (port - 1),
 493                          &regval,
 494                          2);
 495
 496         switch (FIELD_GET(PORT_RESISTANCE_RSN_MASK, regval)) {
 497         case PORT_RESISTANCE_RSN_OTHER:
 498                 return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB) / 10000;
 499         case PORT_RESISTANCE_RSN_LOW:
 500                 return (FIELD_GET(PORT_RESISTANCE_MASK, regval) * RESISTANCE_LSB_LOW) / 10000;
 501         case PORT_RESISTANCE_RSN_SHORT:
 502         case PORT_RESISTANCE_RSN_OPEN:
 503         default:
 504                 return 0;
 505         }
 506 }
 507
 508 static int tps23861_port_status_show(struct seq_file *s, void *data)
 509 {
 510         struct tps23861_data *priv = s->private;
 511         int i;
 512
 513         for (i = 1; i < TPS23861_NUM_PORTS + 1; i++) {
 514                 seq_printf(s, "Port: \t\t%d\n", i);
 515                 seq_printf(s, "Operating mode: %s\n", tps23861_port_operating_mode(priv, i));
 516                 seq_printf(s, "Detected: \t%s\n", tps23861_port_detect_status(priv, i));
 517                 seq_printf(s, "Class: \t\t%s\n", tps23861_port_class_status(priv, i));
 518                 seq_printf(s, "PoE Plus: \t%s\n", tps23861_port_poe_plus_status(priv, i));
 519                 seq_printf(s, "Resistance: \t%d\n", tps23861_port_resistance(priv, i));
 520                 seq_putc(s, '\n');
 521         }
 522
 523         return 0;
 524 }
 525
 526 DEFINE_SHOW_ATTRIBUTE(tps23861_port_status);
 527
 528 static void tps23861_init_debugfs(struct tps23861_data *data)
 529 {
 530         data->debugfs_dir = debugfs_create_dir(data->client->name, NULL);
 531
 532         debugfs_create_file("port_status",
 533                             0400,
 534                             data->debugfs_dir,
 535                             data,
 536                             &tps23861_port_status_fops);
 537 }
 538
 539 static int tps23861_probe(struct i2c_client *client)
 540 {
 541         struct device *dev = &client->dev;
 542         struct tps23861_data *data;
 543         struct device *hwmon_dev;
 544         u32 shunt_resistor;
 545
 546         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 547         if (!data)
 548                 return -ENOMEM;
 549
 550         data->client = client;
 551         i2c_set_clientdata(client, data);
 552
 553         data->regmap = devm_regmap_init_i2c(client, &tps23861_regmap_config);
 554         if (IS_ERR(data->regmap)) {
 555                 dev_err(dev, "failed to allocate register map\n");
 556                 return PTR_ERR(data->regmap);
 557         }
 558
 559         if (!of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &shunt_resistor))
 560                 data->shunt_resistor = shunt_resistor;
 561         else
 562                 data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
 563
 564         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 565                                                          data, &tps23861_chip_info,
 566                                                          NULL);
 567         if (IS_ERR(hwmon_dev))
 568                 return PTR_ERR(hwmon_dev);
 569
 570         tps23861_init_debugfs(data);
 571
 572         return 0;
 573 }
 574
 575 static int tps23861_remove(struct i2c_client *client)
 576 {
 577         struct tps23861_data *data = i2c_get_clientdata(client);
 578
 579         debugfs_remove_recursive(data->debugfs_dir);
 580
 581         return 0;
 582 }
 583
 584 static const struct of_device_id __maybe_unused tps23861_of_match[] = {
 585         { .compatible = "ti,tps23861", },
 586         { },
 587 };
 588 MODULE_DEVICE_TABLE(of, tps23861_of_match);
 589
 590 static struct i2c_driver tps23861_driver = {
 591         .probe_new              = tps23861_probe,
 592         .remove                 = tps23861_remove,
 593         .driver = {
 594                 .name           = "tps23861",
 595                 .of_match_table = of_match_ptr(tps23861_of_match),
 596         },
 597 };
 598 module_i2c_driver(tps23861_driver);
 599
 600 MODULE_LICENSE("GPL");
 601 MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
 602 MODULE_DESCRIPTION("TI TPS23861 PoE PSE");