LXR linux/drivers/hwmon/max6621.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Hardware monitoring driver for Maxim MAX6621
   4 *
   5 * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
   6 * Copyright (c) 2017 Vadim Pasternak <vadimp@mellanox.com>
   7 */
   8
   9#include <linux/bitops.h>
  10#include <linux/hwmon.h>
  11#include <linux/hwmon-sysfs.h>
  12#include <linux/i2c.h>
  13#include <linux/init.h>
  14#include <linux/module.h>
  15#include <linux/of_device.h>
  16#include <linux/regmap.h>
  17
  18#define MAX6621_DRV_NAME                "max6621"
  19#define MAX6621_TEMP_INPUT_REG_NUM      9
  20#define MAX6621_TEMP_INPUT_MIN          -127000
  21#define MAX6621_TEMP_INPUT_MAX          128000
  22#define MAX6621_TEMP_ALERT_CHAN_SHIFT   1
  23
  24#define MAX6621_TEMP_S0D0_REG           0x00
  25#define MAX6621_TEMP_S0D1_REG           0x01
  26#define MAX6621_TEMP_S1D0_REG           0x02
  27#define MAX6621_TEMP_S1D1_REG           0x03
  28#define MAX6621_TEMP_S2D0_REG           0x04
  29#define MAX6621_TEMP_S2D1_REG           0x05
  30#define MAX6621_TEMP_S3D0_REG           0x06
  31#define MAX6621_TEMP_S3D1_REG           0x07
  32#define MAX6621_TEMP_MAX_REG            0x08
  33#define MAX6621_TEMP_MAX_ADDR_REG       0x0a
  34#define MAX6621_TEMP_ALERT_CAUSE_REG    0x0b
  35#define MAX6621_CONFIG0_REG             0x0c
  36#define MAX6621_CONFIG1_REG             0x0d
  37#define MAX6621_CONFIG2_REG             0x0e
  38#define MAX6621_CONFIG3_REG             0x0f
  39#define MAX6621_TEMP_S0_ALERT_REG       0x10
  40#define MAX6621_TEMP_S1_ALERT_REG       0x11
  41#define MAX6621_TEMP_S2_ALERT_REG       0x12
  42#define MAX6621_TEMP_S3_ALERT_REG       0x13
  43#define MAX6621_CLEAR_ALERT_REG         0x15
  44#define MAX6621_REG_MAX                 (MAX6621_CLEAR_ALERT_REG + 1)
  45#define MAX6621_REG_TEMP_SHIFT          0x06
  46
  47#define MAX6621_ENABLE_TEMP_ALERTS_BIT  4
  48#define MAX6621_ENABLE_I2C_CRC_BIT      5
  49#define MAX6621_ENABLE_ALTERNATE_DATA   6
  50#define MAX6621_ENABLE_LOCKUP_TO        7
  51#define MAX6621_ENABLE_S0D0_BIT         8
  52#define MAX6621_ENABLE_S3D1_BIT         15
  53#define MAX6621_ENABLE_TEMP_ALL         GENMASK(MAX6621_ENABLE_S3D1_BIT, \
  54                                                MAX6621_ENABLE_S0D0_BIT)
  55#define MAX6621_POLL_DELAY_MASK         0x5
  56#define MAX6621_CONFIG0_INIT            (MAX6621_ENABLE_TEMP_ALL | \
  57                                         BIT(MAX6621_ENABLE_LOCKUP_TO) | \
  58                                         BIT(MAX6621_ENABLE_I2C_CRC_BIT) | \
  59                                         MAX6621_POLL_DELAY_MASK)
  60#define MAX6621_PECI_BIT_TIME           0x2
  61#define MAX6621_PECI_RETRY_NUM          0x3
  62#define MAX6621_CONFIG1_INIT            ((MAX6621_PECI_BIT_TIME << 8) | \
  63                                         MAX6621_PECI_RETRY_NUM)
  64
  65/* Error codes */
  66#define MAX6621_TRAN_FAILED     0x8100  /*
  67                                         * PECI transaction failed for more
  68                                         * than the configured number of
  69                                         * consecutive retries.
  70                                         */
  71#define MAX6621_POOL_DIS        0x8101  /*
  72                                         * Polling disabled for requested
  73                                         * socket/domain.
  74                                         */
  75#define MAX6621_POOL_UNCOMPLETE 0x8102  /*
  76                                         * First poll not yet completed for
  77                                         * requested socket/domain (on
  78                                         * startup).
  79                                         */
  80#define MAX6621_SD_DIS          0x8103  /*
  81                                         * Read maximum temperature requested,
  82                                         * but no sockets/domains enabled or
  83                                         * all enabled sockets/domains have
  84                                         * errors; or read maximum temperature
  85                                         * address requested, but read maximum
  86                                         * temperature was not called.
  87                                         */
  88#define MAX6621_ALERT_DIS       0x8104  /*
  89                                         * Get alert socket/domain requested,
  90                                         * but no alert active.
  91                                         */
  92#define MAX6621_PECI_ERR_MIN    0x8000  /* Intel spec PECI error min value. */
  93#define MAX6621_PECI_ERR_MAX    0x80ff  /* Intel spec PECI error max value. */
  94
  95static const u32 max6621_temp_regs[] = {
  96        MAX6621_TEMP_MAX_REG, MAX6621_TEMP_S0D0_REG, MAX6621_TEMP_S1D0_REG,
  97        MAX6621_TEMP_S2D0_REG, MAX6621_TEMP_S3D0_REG, MAX6621_TEMP_S0D1_REG,
  98        MAX6621_TEMP_S1D1_REG, MAX6621_TEMP_S2D1_REG, MAX6621_TEMP_S3D1_REG,
  99};
 100
 101static const char *const max6621_temp_labels[] = {
 102        "maximum",
 103        "socket0_0",
 104        "socket1_0",
 105        "socket2_0",
 106        "socket3_0",
 107        "socket0_1",
 108        "socket1_1",
 109        "socket2_1",
 110        "socket3_1",
 111};
 112
 113static const int max6621_temp_alert_chan2reg[] = {
 114        MAX6621_TEMP_S0_ALERT_REG,
 115        MAX6621_TEMP_S1_ALERT_REG,
 116        MAX6621_TEMP_S2_ALERT_REG,
 117        MAX6621_TEMP_S3_ALERT_REG,
 118};
 119
 120/**
 121 * struct max6621_data - private data:
 122 *
 123 * @client: I2C client;
 124 * @regmap: register map handle;
 125 * @input_chan2reg: mapping from channel to register;
 126 */
 127struct max6621_data {
 128        struct i2c_client       *client;
 129        struct regmap           *regmap;
 130        int                     input_chan2reg[MAX6621_TEMP_INPUT_REG_NUM + 1];
 131};
 132
 133static long max6621_temp_mc2reg(long val)
 134{
 135        return (val / 1000L) << MAX6621_REG_TEMP_SHIFT;
 136}
 137
 138static umode_t
 139max6621_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
 140                   int channel)
 141{
 142        /* Skip channels which are not physically conncted. */
 143        if (((struct max6621_data *)data)->input_chan2reg[channel] < 0)
 144                return 0;
 145
 146        switch (type) {
 147        case hwmon_temp:
 148                switch (attr) {
 149                case hwmon_temp_input:
 150                case hwmon_temp_label:
 151                case hwmon_temp_crit_alarm:
 152                        return 0444;
 153                case hwmon_temp_offset:
 154                case hwmon_temp_crit:
 155                        return 0644;
 156                default:
 157                        break;
 158                }
 159
 160        default:
 161                break;
 162        }
 163
 164        return 0;
 165}
 166
 167static int max6621_verify_reg_data(struct device *dev, int regval)
 168{
 169        if (regval >= MAX6621_PECI_ERR_MIN &&
 170            regval <= MAX6621_PECI_ERR_MAX) {
 171                dev_dbg(dev, "PECI error code - err 0x%04x.\n",
 172                        regval);
 173
 174                return -EIO;
 175        }
 176
 177        switch (regval) {
 178        case MAX6621_TRAN_FAILED:
 179                dev_dbg(dev, "PECI transaction failed - err 0x%04x.\n",
 180                        regval);
 181                return -EIO;
 182        case MAX6621_POOL_DIS:
 183                dev_dbg(dev, "Polling disabled - err 0x%04x.\n", regval);
 184                return -EOPNOTSUPP;
 185        case MAX6621_POOL_UNCOMPLETE:
 186                dev_dbg(dev, "First poll not completed on startup - err 0x%04x.\n",
 187                        regval);
 188                return -EIO;
 189        case MAX6621_SD_DIS:
 190                dev_dbg(dev, "Resource is disabled - err 0x%04x.\n", regval);
 191                return -EOPNOTSUPP;
 192        case MAX6621_ALERT_DIS:
 193                dev_dbg(dev, "No alert active - err 0x%04x.\n", regval);
 194                return -EOPNOTSUPP;
 195        default:
 196                return 0;
 197        }
 198}
 199
 200static int
 201max6621_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 202             int channel, long *val)
 203{
 204        struct max6621_data *data = dev_get_drvdata(dev);
 205        u32 regval;
 206        int reg;
 207        s8 temp;
 208        int ret;
 209
 210        switch (type) {
 211        case hwmon_temp:
 212                switch (attr) {
 213                case hwmon_temp_input:
 214                        reg = data->input_chan2reg[channel];
 215                        ret = regmap_read(data->regmap, reg, &regval);
 216                        if (ret)
 217                                return ret;
 218
 219                        ret = max6621_verify_reg_data(dev, regval);
 220                        if (ret)
 221                                return ret;
 222
 223                        /*
 224                         * Bit MAX6621_REG_TEMP_SHIFT represents 1 degree step.
 225                         * The temperature is given in two's complement and 8
 226                         * bits is used for the register conversion.
 227                         */
 228                        temp = (regval >> MAX6621_REG_TEMP_SHIFT);
 229                        *val = temp * 1000L;
 230
 231                        break;
 232                case hwmon_temp_offset:
 233                        ret = regmap_read(data->regmap, MAX6621_CONFIG2_REG,
 234                                          &regval);
 235                        if (ret)
 236                                return ret;
 237
 238                        ret = max6621_verify_reg_data(dev, regval);
 239                        if (ret)
 240                                return ret;
 241
 242                        *val = (regval >> MAX6621_REG_TEMP_SHIFT) *
 243                               1000L;
 244
 245                        break;
 246                case hwmon_temp_crit:
 247                        channel -= MAX6621_TEMP_ALERT_CHAN_SHIFT;
 248                        reg = max6621_temp_alert_chan2reg[channel];
 249                        ret = regmap_read(data->regmap, reg, &regval);
 250                        if (ret)
 251                                return ret;
 252
 253                        ret = max6621_verify_reg_data(dev, regval);
 254                        if (ret)
 255                                return ret;
 256
 257                        *val = regval * 1000L;
 258
 259                        break;
 260                case hwmon_temp_crit_alarm:
 261                        /*
 262                         * Set val to zero to recover the case, when reading
 263                         * MAX6621_TEMP_ALERT_CAUSE_REG results in for example
 264                         * MAX6621_ALERT_DIS. Reading will return with error,
 265                         * but in such case alarm should be returned as 0.
 266                         */
 267                        *val = 0;
 268                        ret = regmap_read(data->regmap,
 269                                          MAX6621_TEMP_ALERT_CAUSE_REG,
 270                                          &regval);
 271                        if (ret)
 272                                return ret;
 273
 274                        ret = max6621_verify_reg_data(dev, regval);
 275                        if (ret) {
 276                                /* Do not report error if alert is disabled. */
 277                                if (regval == MAX6621_ALERT_DIS)
 278                                        return 0;
 279                                else
 280                                        return ret;
 281                        }
 282
 283                        /*
 284                         * Clear the alert automatically, using send-byte
 285                         * smbus protocol for clearing alert.
 286                         */
 287                        if (regval) {
 288                                ret = i2c_smbus_write_byte(data->client,
 289                                                MAX6621_CLEAR_ALERT_REG);
 290                                if (ret)
 291                                        return ret;
 292                        }
 293
 294                        *val = !!regval;
 295
 296                        break;
 297                default:
 298                        return -EOPNOTSUPP;
 299                }
 300                break;
 301
 302        default:
 303                return -EOPNOTSUPP;
 304        }
 305
 306        return 0;
 307}
 308
 309static int
 310max6621_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 311              int channel, long val)
 312{
 313        struct max6621_data *data = dev_get_drvdata(dev);
 314        u32 reg;
 315
 316        switch (type) {
 317        case hwmon_temp:
 318                switch (attr) {
 319                case hwmon_temp_offset:
 320                        /* Clamp to allowed range to prevent overflow. */
 321                        val = clamp_val(val, MAX6621_TEMP_INPUT_MIN,
 322                                        MAX6621_TEMP_INPUT_MAX);
 323                        val = max6621_temp_mc2reg(val);
 324
 325                        return regmap_write(data->regmap,
 326                                            MAX6621_CONFIG2_REG, val);
 327                case hwmon_temp_crit:
 328                        channel -= MAX6621_TEMP_ALERT_CHAN_SHIFT;
 329                        reg = max6621_temp_alert_chan2reg[channel];
 330                        /* Clamp to allowed range to prevent overflow. */
 331                        val = clamp_val(val, MAX6621_TEMP_INPUT_MIN,
 332                                        MAX6621_TEMP_INPUT_MAX);
 333                        val = val / 1000L;
 334
 335                        return regmap_write(data->regmap, reg, val);
 336                default:
 337                        return -EOPNOTSUPP;
 338                }
 339                break;
 340
 341        default:
 342                return -EOPNOTSUPP;
 343        }
 344
 345        return -EOPNOTSUPP;
 346}
 347
 348static int
 349max6621_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 350                    int channel, const char **str)
 351{
 352        switch (type) {
 353        case hwmon_temp:
 354                switch (attr) {
 355                case hwmon_temp_label:
 356                        *str = max6621_temp_labels[channel];
 357                        return 0;
 358                default:
 359                        return -EOPNOTSUPP;
 360                }
 361                break;
 362        default:
 363                return -EOPNOTSUPP;
 364        }
 365
 366        return -EOPNOTSUPP;
 367}
 368
 369static bool max6621_writeable_reg(struct device *dev, unsigned int reg)
 370{
 371        switch (reg) {
 372        case MAX6621_CONFIG0_REG:
 373        case MAX6621_CONFIG1_REG:
 374        case MAX6621_CONFIG2_REG:
 375        case MAX6621_CONFIG3_REG:
 376        case MAX6621_TEMP_S0_ALERT_REG:
 377        case MAX6621_TEMP_S1_ALERT_REG:
 378        case MAX6621_TEMP_S2_ALERT_REG:
 379        case MAX6621_TEMP_S3_ALERT_REG:
 380        case MAX6621_TEMP_ALERT_CAUSE_REG:
 381                return true;
 382        }
 383        return false;
 384}
 385
 386static bool max6621_readable_reg(struct device *dev, unsigned int reg)
 387{
 388        switch (reg) {
 389        case MAX6621_TEMP_S0D0_REG:
 390        case MAX6621_TEMP_S0D1_REG:
 391        case MAX6621_TEMP_S1D0_REG:
 392        case MAX6621_TEMP_S1D1_REG:
 393        case MAX6621_TEMP_S2D0_REG:
 394        case MAX6621_TEMP_S2D1_REG:
 395        case MAX6621_TEMP_S3D0_REG:
 396        case MAX6621_TEMP_S3D1_REG:
 397        case MAX6621_TEMP_MAX_REG:
 398        case MAX6621_TEMP_MAX_ADDR_REG:
 399        case MAX6621_CONFIG0_REG:
 400        case MAX6621_CONFIG1_REG:
 401        case MAX6621_CONFIG2_REG:
 402        case MAX6621_CONFIG3_REG:
 403        case MAX6621_TEMP_S0_ALERT_REG:
 404        case MAX6621_TEMP_S1_ALERT_REG:
 405        case MAX6621_TEMP_S2_ALERT_REG:
 406        case MAX6621_TEMP_S3_ALERT_REG:
 407                return true;
 408        }
 409        return false;
 410}
 411
 412static bool max6621_volatile_reg(struct device *dev, unsigned int reg)
 413{
 414        switch (reg) {
 415        case MAX6621_TEMP_S0D0_REG:
 416        case MAX6621_TEMP_S0D1_REG:
 417        case MAX6621_TEMP_S1D0_REG:
 418        case MAX6621_TEMP_S1D1_REG:
 419        case MAX6621_TEMP_S2D0_REG:
 420        case MAX6621_TEMP_S2D1_REG:
 421        case MAX6621_TEMP_S3D0_REG:
 422        case MAX6621_TEMP_S3D1_REG:
 423        case MAX6621_TEMP_MAX_REG:
 424        case MAX6621_TEMP_S0_ALERT_REG:
 425        case MAX6621_TEMP_S1_ALERT_REG:
 426        case MAX6621_TEMP_S2_ALERT_REG:
 427        case MAX6621_TEMP_S3_ALERT_REG:
 428        case MAX6621_TEMP_ALERT_CAUSE_REG:
 429                return true;
 430        }
 431        return false;
 432}
 433
 434static const struct reg_default max6621_regmap_default[] = {
 435        { MAX6621_CONFIG0_REG, MAX6621_CONFIG0_INIT },
 436        { MAX6621_CONFIG1_REG, MAX6621_CONFIG1_INIT },
 437};
 438
 439static const struct regmap_config max6621_regmap_config = {
 440        .reg_bits = 8,
 441        .val_bits = 16,
 442        .max_register = MAX6621_REG_MAX,
 443        .val_format_endian = REGMAP_ENDIAN_LITTLE,
 444        .cache_type = REGCACHE_FLAT,
 445        .writeable_reg = max6621_writeable_reg,
 446        .readable_reg = max6621_readable_reg,
 447        .volatile_reg = max6621_volatile_reg,
 448        .reg_defaults = max6621_regmap_default,
 449        .num_reg_defaults = ARRAY_SIZE(max6621_regmap_default),
 450};
 451
 452static const struct hwmon_channel_info *max6621_info[] = {
 453        HWMON_CHANNEL_INFO(chip,
 454                           HWMON_C_REGISTER_TZ),
 455        HWMON_CHANNEL_INFO(temp,
 456                           HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_OFFSET,
 457                           HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
 458                           HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
 459                           HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
 460                           HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
 461                           HWMON_T_INPUT | HWMON_T_LABEL,
 462                           HWMON_T_INPUT | HWMON_T_LABEL,
 463                           HWMON_T_INPUT | HWMON_T_LABEL,
 464                           HWMON_T_INPUT | HWMON_T_LABEL),
 465        NULL
 466};
 467
 468static const struct hwmon_ops max6621_hwmon_ops = {
 469        .read = max6621_read,
 470        .write = max6621_write,
 471        .read_string = max6621_read_string,
 472        .is_visible = max6621_is_visible,
 473};
 474
 475static const struct hwmon_chip_info max6621_chip_info = {
 476        .ops = &max6621_hwmon_ops,
 477        .info = max6621_info,
 478};
 479
 480static int max6621_probe(struct i2c_client *client)
 481{
 482        struct device *dev = &client->dev;
 483        struct max6621_data *data;
 484        struct device *hwmon_dev;
 485        int i;
 486        int ret;
 487
 488        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 489        if (!data)
 490                return -ENOMEM;
 491
 492        data->regmap = devm_regmap_init_i2c(client, &max6621_regmap_config);
 493        if (IS_ERR(data->regmap))
 494                return PTR_ERR(data->regmap);
 495
 496        i2c_set_clientdata(client, data);
 497        data->client = client;
 498
 499        /* Set CONFIG0 register masking temperature alerts and PEC. */
 500        ret = regmap_write(data->regmap, MAX6621_CONFIG0_REG,
 501                           MAX6621_CONFIG0_INIT);
 502        if (ret)
 503                return ret;
 504
 505        /* Set CONFIG1 register for PEC access retry number. */
 506        ret = regmap_write(data->regmap, MAX6621_CONFIG1_REG,
 507                           MAX6621_CONFIG1_INIT);
 508        if (ret)
 509                return ret;
 510
 511        /* Sync registers with hardware. */
 512        regcache_mark_dirty(data->regmap);
 513        ret = regcache_sync(data->regmap);
 514        if (ret)
 515                return ret;
 516
 517        /* Verify which temperature input registers are enabled. */
 518        for (i = 0; i < MAX6621_TEMP_INPUT_REG_NUM; i++) {
 519                ret = i2c_smbus_read_word_data(client, max6621_temp_regs[i]);
 520                if (ret < 0)
 521                        return ret;
 522                ret = max6621_verify_reg_data(dev, ret);
 523                if (ret) {
 524                        data->input_chan2reg[i] = -1;
 525                        continue;
 526                }
 527
 528                data->input_chan2reg[i] = max6621_temp_regs[i];
 529        }
 530
 531        hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 532                                                         data,
 533                                                         &max6621_chip_info,
 534                                                         NULL);
 535
 536        return PTR_ERR_OR_ZERO(hwmon_dev);
 537}
 538
 539static const struct i2c_device_id max6621_id[] = {
 540        { MAX6621_DRV_NAME, 0 },
 541        { }
 542};
 543MODULE_DEVICE_TABLE(i2c, max6621_id);
 544
 545static const struct of_device_id __maybe_unused max6621_of_match[] = {
 546        { .compatible = "maxim,max6621" },
 547        { }
 548};
 549MODULE_DEVICE_TABLE(of, max6621_of_match);
 550
 551static struct i2c_driver max6621_driver = {
 552        .class          = I2C_CLASS_HWMON,
 553        .driver = {
 554                .name = MAX6621_DRV_NAME,
 555                .of_match_table = of_match_ptr(max6621_of_match),
 556        },
 557        .probe_new      = max6621_probe,
 558        .id_table       = max6621_id,
 559};
 560
 561module_i2c_driver(max6621_driver);
 562
 563MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 564MODULE_DESCRIPTION("Driver for Maxim MAX6621");
 565MODULE_LICENSE("GPL");
 566