drivers/hwmon/asus-ec-sensors.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * HWMON driver for ASUS motherboards that publish some sensor values
   4  * via the embedded controller registers.
   5  *
   6  * Copyright (C) 2021 Eugene Shalygin <eugene.shalygin@gmail.com>
   7
   8  * EC provides:
   9  * - Chipset temperature
  10  * - CPU temperature
  11  * - Motherboard temperature
  12  * - T_Sensor temperature
  13  * - VRM temperature
  14  * - Water In temperature
  15  * - Water Out temperature
  16  * - CPU Optional fan RPM
  17  * - Chipset fan RPM
  18  * - VRM Heat Sink fan RPM
  19  * - Water Flow fan RPM
  20  * - CPU current
  21  * - CPU core voltage
  22  */
  23
  24 #include <linux/acpi.h>
  25 #include <linux/bitops.h>
  26 #include <linux/dev_printk.h>
  27 #include <linux/dmi.h>
  28 #include <linux/hwmon.h>
  29 #include <linux/init.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/sort.h>
  35 #include <linux/units.h>
  36
  37 #include <asm/unaligned.h>
  38
  39 static char *mutex_path_override;
  40
  41 /* Writing to this EC register switches EC bank */
  42 #define ASUS_EC_BANK_REGISTER   0xff
  43 #define SENSOR_LABEL_LEN        16
  44
  45 /*
  46  * Arbitrary set max. allowed bank number. Required for sorting banks and
  47  * currently is overkill with just 2 banks used at max, but for the sake
  48  * of alignment let's set it to a higher value.
  49  */
  50 #define ASUS_EC_MAX_BANK        3
  51
  52 #define ACPI_LOCK_DELAY_MS      500
  53
  54 /* ACPI mutex for locking access to the EC for the firmware */
  55 #define ASUS_HW_ACCESS_MUTEX_ASMX       "\\AMW0.ASMX"
  56
  57 #define MAX_IDENTICAL_BOARD_VARIATIONS  3
  58
  59 /* Moniker for the ACPI global lock (':' is not allowed in ASL identifiers) */
  60 #define ACPI_GLOBAL_LOCK_PSEUDO_PATH    ":GLOBAL_LOCK"
  61
  62 typedef union {
  63         u32 value;
  64         struct {
  65                 u8 index;
  66                 u8 bank;
  67                 u8 size;
  68                 u8 dummy;
  69         } components;
  70 } sensor_address;
  71
  72 #define MAKE_SENSOR_ADDRESS(size, bank, index) {                               \
  73                 .value = (size << 16) + (bank << 8) + index                    \
  74         }
  75
  76 static u32 hwmon_attributes[hwmon_max] = {
  77         [hwmon_chip] = HWMON_C_REGISTER_TZ,
  78         [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,
  79         [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
  80         [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
  81         [hwmon_fan] = HWMON_F_INPUT | HWMON_F_LABEL,
  82 };
  83
  84 struct ec_sensor_info {
  85         char label[SENSOR_LABEL_LEN];
  86         enum hwmon_sensor_types type;
  87         sensor_address addr;
  88 };
  89
  90 #define EC_SENSOR(sensor_label, sensor_type, size, bank, index) {              \
  91                 .label = sensor_label, .type = sensor_type,                    \
  92                 .addr = MAKE_SENSOR_ADDRESS(size, bank, index),                \
  93         }
  94
  95 enum ec_sensors {
  96         /* chipset temperature [℃] */
  97         ec_sensor_temp_chipset,
  98         /* CPU temperature [℃] */
  99         ec_sensor_temp_cpu,
 100         /* motherboard temperature [℃] */
 101         ec_sensor_temp_mb,
 102         /* "T_Sensor" temperature sensor reading [℃] */
 103         ec_sensor_temp_t_sensor,
 104         /* VRM temperature [℃] */
 105         ec_sensor_temp_vrm,
 106         /* CPU Core voltage [mV] */
 107         ec_sensor_in_cpu_core,
 108         /* CPU_Opt fan [RPM] */
 109         ec_sensor_fan_cpu_opt,
 110         /* VRM heat sink fan [RPM] */
 111         ec_sensor_fan_vrm_hs,
 112         /* Chipset fan [RPM] */
 113         ec_sensor_fan_chipset,
 114         /* Water flow sensor reading [RPM] */
 115         ec_sensor_fan_water_flow,
 116         /* CPU current [A] */
 117         ec_sensor_curr_cpu,
 118         /* "Water_In" temperature sensor reading [℃] */
 119         ec_sensor_temp_water_in,
 120         /* "Water_Out" temperature sensor reading [℃] */
 121         ec_sensor_temp_water_out,
 122 };
 123
 124 #define SENSOR_TEMP_CHIPSET BIT(ec_sensor_temp_chipset)
 125 #define SENSOR_TEMP_CPU BIT(ec_sensor_temp_cpu)
 126 #define SENSOR_TEMP_MB BIT(ec_sensor_temp_mb)
 127 #define SENSOR_TEMP_T_SENSOR BIT(ec_sensor_temp_t_sensor)
 128 #define SENSOR_TEMP_VRM BIT(ec_sensor_temp_vrm)
 129 #define SENSOR_IN_CPU_CORE BIT(ec_sensor_in_cpu_core)
 130 #define SENSOR_FAN_CPU_OPT BIT(ec_sensor_fan_cpu_opt)
 131 #define SENSOR_FAN_VRM_HS BIT(ec_sensor_fan_vrm_hs)
 132 #define SENSOR_FAN_CHIPSET BIT(ec_sensor_fan_chipset)
 133 #define SENSOR_FAN_WATER_FLOW BIT(ec_sensor_fan_water_flow)
 134 #define SENSOR_CURR_CPU BIT(ec_sensor_curr_cpu)
 135 #define SENSOR_TEMP_WATER_IN BIT(ec_sensor_temp_water_in)
 136 #define SENSOR_TEMP_WATER_OUT BIT(ec_sensor_temp_water_out)
 137
 138 enum board_family {
 139         family_unknown,
 140         family_amd_400_series,
 141         family_amd_500_series,
 142 };
 143
 144 /* All the known sensors for ASUS EC controllers */
 145 static const struct ec_sensor_info sensors_family_amd_400[] = {
 146         [ec_sensor_temp_chipset] =
 147                 EC_SENSOR("Chipset", hwmon_temp, 1, 0x00, 0x3a),
 148         [ec_sensor_temp_cpu] =
 149                 EC_SENSOR("CPU", hwmon_temp, 1, 0x00, 0x3b),
 150         [ec_sensor_temp_mb] =
 151                 EC_SENSOR("Motherboard", hwmon_temp, 1, 0x00, 0x3c),
 152         [ec_sensor_temp_t_sensor] =
 153                 EC_SENSOR("T_Sensor", hwmon_temp, 1, 0x00, 0x3d),
 154         [ec_sensor_temp_vrm] =
 155                 EC_SENSOR("VRM", hwmon_temp, 1, 0x00, 0x3e),
 156         [ec_sensor_in_cpu_core] =
 157                 EC_SENSOR("CPU Core", hwmon_in, 2, 0x00, 0xa2),
 158         [ec_sensor_fan_cpu_opt] =
 159                 EC_SENSOR("CPU_Opt", hwmon_fan, 2, 0x00, 0xbc),
 160         [ec_sensor_fan_vrm_hs] =
 161                 EC_SENSOR("VRM HS", hwmon_fan, 2, 0x00, 0xb2),
 162         [ec_sensor_fan_chipset] =
 163                 /* no chipset fans in this generation */
 164                 EC_SENSOR("Chipset", hwmon_fan, 0, 0x00, 0x00),
 165         [ec_sensor_fan_water_flow] =
 166                 EC_SENSOR("Water_Flow", hwmon_fan, 2, 0x00, 0xb4),
 167         [ec_sensor_curr_cpu] =
 168                 EC_SENSOR("CPU", hwmon_curr, 1, 0x00, 0xf4),
 169         [ec_sensor_temp_water_in] =
 170                 EC_SENSOR("Water_In", hwmon_temp, 1, 0x01, 0x0d),
 171         [ec_sensor_temp_water_out] =
 172                 EC_SENSOR("Water_Out", hwmon_temp, 1, 0x01, 0x0b),
 173 };
 174
 175 static const struct ec_sensor_info sensors_family_amd_500[] = {
 176         [ec_sensor_temp_chipset] =
 177                 EC_SENSOR("Chipset", hwmon_temp, 1, 0x00, 0x3a),
 178         [ec_sensor_temp_cpu] = EC_SENSOR("CPU", hwmon_temp, 1, 0x00, 0x3b),
 179         [ec_sensor_temp_mb] =
 180                 EC_SENSOR("Motherboard", hwmon_temp, 1, 0x00, 0x3c),
 181         [ec_sensor_temp_t_sensor] =
 182                 EC_SENSOR("T_Sensor", hwmon_temp, 1, 0x00, 0x3d),
 183         [ec_sensor_temp_vrm] = EC_SENSOR("VRM", hwmon_temp, 1, 0x00, 0x3e),
 184         [ec_sensor_in_cpu_core] =
 185                 EC_SENSOR("CPU Core", hwmon_in, 2, 0x00, 0xa2),
 186         [ec_sensor_fan_cpu_opt] =
 187                 EC_SENSOR("CPU_Opt", hwmon_fan, 2, 0x00, 0xb0),
 188         [ec_sensor_fan_vrm_hs] = EC_SENSOR("VRM HS", hwmon_fan, 2, 0x00, 0xb2),
 189         [ec_sensor_fan_chipset] =
 190                 EC_SENSOR("Chipset", hwmon_fan, 2, 0x00, 0xb4),
 191         [ec_sensor_fan_water_flow] =
 192                 EC_SENSOR("Water_Flow", hwmon_fan, 2, 0x00, 0xbc),
 193         [ec_sensor_curr_cpu] = EC_SENSOR("CPU", hwmon_curr, 1, 0x00, 0xf4),
 194         [ec_sensor_temp_water_in] =
 195                 EC_SENSOR("Water_In", hwmon_temp, 1, 0x01, 0x00),
 196         [ec_sensor_temp_water_out] =
 197                 EC_SENSOR("Water_Out", hwmon_temp, 1, 0x01, 0x01),
 198 };
 199
 200 /* Shortcuts for common combinations */
 201 #define SENSOR_SET_TEMP_CHIPSET_CPU_MB                                         \
 202         (SENSOR_TEMP_CHIPSET | SENSOR_TEMP_CPU | SENSOR_TEMP_MB)
 203 #define SENSOR_SET_TEMP_WATER (SENSOR_TEMP_WATER_IN | SENSOR_TEMP_WATER_OUT)
 204
 205 struct ec_board_info {
 206         const char *board_names[MAX_IDENTICAL_BOARD_VARIATIONS];
 207         unsigned long sensors;
 208         /*
 209          * Defines which mutex to use for guarding access to the state and the
 210          * hardware. Can be either a full path to an AML mutex or the
 211          * pseudo-path ACPI_GLOBAL_LOCK_PSEUDO_PATH to use the global ACPI lock,
 212          * or left empty to use a regular mutex object, in which case access to
 213          * the hardware is not guarded.
 214          */
 215         const char *mutex_path;
 216         enum board_family family;
 217 };
 218
 219 static const struct ec_board_info board_info[] = {
 220         {
 221                 .board_names = {"PRIME X470-PRO"},
 222                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 223                         SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
 224                         SENSOR_FAN_CPU_OPT |
 225                         SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
 226                 .mutex_path = ACPI_GLOBAL_LOCK_PSEUDO_PATH,
 227                 .family = family_amd_400_series,
 228         },
 229         {
 230                 .board_names = {"PRIME X570-PRO"},
 231                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB | SENSOR_TEMP_VRM |
 232                         SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CHIPSET,
 233                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 234                 .family = family_amd_500_series,
 235         },
 236         {
 237                 .board_names = {"ProArt X570-CREATOR WIFI"},
 238                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB | SENSOR_TEMP_VRM |
 239                         SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CPU_OPT |
 240                         SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
 241         },
 242         {
 243                 .board_names = {"Pro WS X570-ACE"},
 244                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB | SENSOR_TEMP_VRM |
 245                         SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CHIPSET |
 246                         SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
 247                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 248                 .family = family_amd_500_series,
 249         },
 250         {
 251                 .board_names = {"ROG CROSSHAIR VIII DARK HERO"},
 252                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 253                         SENSOR_TEMP_T_SENSOR |
 254                         SENSOR_TEMP_VRM | SENSOR_SET_TEMP_WATER |
 255                         SENSOR_FAN_CPU_OPT | SENSOR_FAN_WATER_FLOW |
 256                         SENSOR_CURR_CPU | SENSOR_IN_CPU_CORE,
 257                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 258                 .family = family_amd_500_series,
 259         },
 260         {
 261                 .board_names = {
 262                         "ROG CROSSHAIR VIII FORMULA",
 263                         "ROG CROSSHAIR VIII HERO",
 264                         "ROG CROSSHAIR VIII HERO (WI-FI)",
 265                 },
 266                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 267                         SENSOR_TEMP_T_SENSOR |
 268                         SENSOR_TEMP_VRM | SENSOR_SET_TEMP_WATER |
 269                         SENSOR_FAN_CPU_OPT | SENSOR_FAN_CHIPSET |
 270                         SENSOR_FAN_WATER_FLOW | SENSOR_CURR_CPU |
 271                         SENSOR_IN_CPU_CORE,
 272                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 273                 .family = family_amd_500_series,
 274         },
 275         {
 276                 .board_names = {"ROG CROSSHAIR VIII IMPACT"},
 277                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 278                         SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
 279                         SENSOR_FAN_CHIPSET | SENSOR_CURR_CPU |
 280                         SENSOR_IN_CPU_CORE,
 281                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 282                 .family = family_amd_500_series,
 283         },
 284         {
 285                 .board_names = {"ROG STRIX B550-E GAMING"},
 286                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 287                         SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
 288                         SENSOR_FAN_CPU_OPT,
 289                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 290                 .family = family_amd_500_series,
 291         },
 292         {
 293                 .board_names = {"ROG STRIX B550-I GAMING"},
 294                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 295                         SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
 296                         SENSOR_FAN_VRM_HS | SENSOR_CURR_CPU |
 297                         SENSOR_IN_CPU_CORE,
 298                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 299                 .family = family_amd_500_series,
 300         },
 301         {
 302                 .board_names = {"ROG STRIX X570-E GAMING"},
 303                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 304                         SENSOR_TEMP_T_SENSOR | SENSOR_TEMP_VRM |
 305                         SENSOR_FAN_CHIPSET | SENSOR_CURR_CPU |
 306                         SENSOR_IN_CPU_CORE,
 307                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 308                 .family = family_amd_500_series,
 309         },
 310         {
 311                 .board_names = {"ROG STRIX X570-E GAMING WIFI II"},
 312                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 313                         SENSOR_TEMP_T_SENSOR | SENSOR_CURR_CPU |
 314                         SENSOR_IN_CPU_CORE,
 315                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 316                 .family = family_amd_500_series,
 317         },
 318         {
 319                 .board_names = {"ROG STRIX X570-F GAMING"},
 320                 .sensors = SENSOR_SET_TEMP_CHIPSET_CPU_MB |
 321                         SENSOR_TEMP_T_SENSOR | SENSOR_FAN_CHIPSET,
 322                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 323                 .family = family_amd_500_series,
 324         },
 325         {
 326                 .board_names = {"ROG STRIX X570-I GAMING"},
 327                 .sensors = SENSOR_TEMP_T_SENSOR | SENSOR_FAN_VRM_HS |
 328                         SENSOR_FAN_CHIPSET | SENSOR_CURR_CPU |
 329                         SENSOR_IN_CPU_CORE,
 330                 .mutex_path = ASUS_HW_ACCESS_MUTEX_ASMX,
 331                 .family = family_amd_500_series,
 332         },
 333         {}
 334 };
 335
 336 struct ec_sensor {
 337         unsigned int info_index;
 338         s32 cached_value;
 339 };
 340
 341 struct lock_data {
 342         union {
 343                 acpi_handle aml;
 344                 /* global lock handle */
 345                 u32 glk;
 346         } mutex;
 347         bool (*lock)(struct lock_data *data);
 348         bool (*unlock)(struct lock_data *data);
 349 };
 350
 351 /*
 352  * The next function pairs implement options for locking access to the
 353  * state and the EC
 354  */
 355 static bool lock_via_acpi_mutex(struct lock_data *data)
 356 {
 357         /*
 358          * ASUS DSDT does not specify that access to the EC has to be guarded,
 359          * but firmware does access it via ACPI
 360          */
 361         return ACPI_SUCCESS(acpi_acquire_mutex(data->mutex.aml,
 362                                                NULL, ACPI_LOCK_DELAY_MS));
 363 }
 364
 365 static bool unlock_acpi_mutex(struct lock_data *data)
 366 {
 367         return ACPI_SUCCESS(acpi_release_mutex(data->mutex.aml, NULL));
 368 }
 369
 370 static bool lock_via_global_acpi_lock(struct lock_data *data)
 371 {
 372         return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS,
 373                                                      &data->mutex.glk));
 374 }
 375
 376 static bool unlock_global_acpi_lock(struct lock_data *data)
 377 {
 378         return ACPI_SUCCESS(acpi_release_global_lock(data->mutex.glk));
 379 }
 380
 381 struct ec_sensors_data {
 382         const struct ec_board_info *board_info;
 383         const struct ec_sensor_info *sensors_info;
 384         struct ec_sensor *sensors;
 385         /* EC registers to read from */
 386         u16 *registers;
 387         u8 *read_buffer;
 388         /* sorted list of unique register banks */
 389         u8 banks[ASUS_EC_MAX_BANK + 1];
 390         /* in jiffies */
 391         unsigned long last_updated;
 392         struct lock_data lock_data;
 393         /* number of board EC sensors */
 394         u8 nr_sensors;
 395         /*
 396          * number of EC registers to read
 397          * (sensor might span more than 1 register)
 398          */
 399         u8 nr_registers;
 400         /* number of unique register banks */
 401         u8 nr_banks;
 402 };
 403
 404 static u8 register_bank(u16 reg)
 405 {
 406         return reg >> 8;
 407 }
 408
 409 static u8 register_index(u16 reg)
 410 {
 411         return reg & 0x00ff;
 412 }
 413
 414 static bool is_sensor_data_signed(const struct ec_sensor_info *si)
 415 {
 416         /*
 417          * guessed from WMI functions in DSDT code for boards
 418          * of the X470 generation
 419          */
 420         return si->type == hwmon_temp;
 421 }
 422
 423 static const struct ec_sensor_info *
 424 get_sensor_info(const struct ec_sensors_data *state, int index)
 425 {
 426         return state->sensors_info + state->sensors[index].info_index;
 427 }
 428
 429 static int find_ec_sensor_index(const struct ec_sensors_data *ec,
 430                                 enum hwmon_sensor_types type, int channel)
 431 {
 432         unsigned int i;
 433
 434         for (i = 0; i < ec->nr_sensors; i++) {
 435                 if (get_sensor_info(ec, i)->type == type) {
 436                         if (channel == 0)
 437                                 return i;
 438                         channel--;
 439                 }
 440         }
 441         return -ENOENT;
 442 }
 443
 444 static int __init bank_compare(const void *a, const void *b)
 445 {
 446         return *((const s8 *)a) - *((const s8 *)b);
 447 }
 448
 449 static void __init setup_sensor_data(struct ec_sensors_data *ec)
 450 {
 451         struct ec_sensor *s = ec->sensors;
 452         bool bank_found;
 453         int i, j;
 454         u8 bank;
 455
 456         ec->nr_banks = 0;
 457         ec->nr_registers = 0;
 458
 459         for_each_set_bit(i, &ec->board_info->sensors,
 460                          BITS_PER_TYPE(ec->board_info->sensors)) {
 461                 s->info_index = i;
 462                 s->cached_value = 0;
 463                 ec->nr_registers +=
 464                         ec->sensors_info[s->info_index].addr.components.size;
 465                 bank_found = false;
 466                 bank = ec->sensors_info[s->info_index].addr.components.bank;
 467                 for (j = 0; j < ec->nr_banks; j++) {
 468                         if (ec->banks[j] == bank) {
 469                                 bank_found = true;
 470                                 break;
 471                         }
 472                 }
 473                 if (!bank_found) {
 474                         ec->banks[ec->nr_banks++] = bank;
 475                 }
 476                 s++;
 477         }
 478         sort(ec->banks, ec->nr_banks, 1, bank_compare, NULL);
 479 }
 480
 481 static void __init fill_ec_registers(struct ec_sensors_data *ec)
 482 {
 483         const struct ec_sensor_info *si;
 484         unsigned int i, j, register_idx = 0;
 485
 486         for (i = 0; i < ec->nr_sensors; ++i) {
 487                 si = get_sensor_info(ec, i);
 488                 for (j = 0; j < si->addr.components.size; ++j, ++register_idx) {
 489                         ec->registers[register_idx] =
 490                                 (si->addr.components.bank << 8) +
 491                                 si->addr.components.index + j;
 492                 }
 493         }
 494 }
 495
 496 static int __init setup_lock_data(struct device *dev)
 497 {
 498         const char *mutex_path;
 499         int status;
 500         struct ec_sensors_data *state = dev_get_drvdata(dev);
 501
 502         mutex_path = mutex_path_override ?
 503                 mutex_path_override : state->board_info->mutex_path;
 504
 505         if (!mutex_path || !strlen(mutex_path)) {
 506                 dev_err(dev, "Hardware access guard mutex name is empty");
 507                 return -EINVAL;
 508         }
 509         if (!strcmp(mutex_path, ACPI_GLOBAL_LOCK_PSEUDO_PATH)) {
 510                 state->lock_data.mutex.glk = 0;
 511                 state->lock_data.lock = lock_via_global_acpi_lock;
 512                 state->lock_data.unlock = unlock_global_acpi_lock;
 513         } else {
 514                 status = acpi_get_handle(NULL, (acpi_string)mutex_path,
 515                                          &state->lock_data.mutex.aml);
 516                 if (ACPI_FAILURE(status)) {
 517                         dev_err(dev,
 518                                 "Failed to get hardware access guard AML mutex '%s': error %d",
 519                                 mutex_path, status);
 520                         return -ENOENT;
 521                 }
 522                 state->lock_data.lock = lock_via_acpi_mutex;
 523                 state->lock_data.unlock = unlock_acpi_mutex;
 524         }
 525         return 0;
 526 }
 527
 528 static int asus_ec_bank_switch(u8 bank, u8 *old)
 529 {
 530         int status = 0;
 531
 532         if (old) {
 533                 status = ec_read(ASUS_EC_BANK_REGISTER, old);
 534         }
 535         if (status || (old && (*old == bank)))
 536                 return status;
 537         return ec_write(ASUS_EC_BANK_REGISTER, bank);
 538 }
 539
 540 static int asus_ec_block_read(const struct device *dev,
 541                               struct ec_sensors_data *ec)
 542 {
 543         int ireg, ibank, status;
 544         u8 bank, reg_bank, prev_bank;
 545
 546         bank = 0;
 547         status = asus_ec_bank_switch(bank, &prev_bank);
 548         if (status) {
 549                 dev_warn(dev, "EC bank switch failed");
 550                 return status;
 551         }
 552
 553         if (prev_bank) {
 554                 /* oops... somebody else is working with the EC too */
 555                 dev_warn(dev,
 556                         "Concurrent access to the ACPI EC detected.\nRace condition possible.");
 557         }
 558
 559         /* read registers minimizing bank switches. */
 560         for (ibank = 0; ibank < ec->nr_banks; ibank++) {
 561                 if (bank != ec->banks[ibank]) {
 562                         bank = ec->banks[ibank];
 563                         if (asus_ec_bank_switch(bank, NULL)) {
 564                                 dev_warn(dev, "EC bank switch to %d failed",
 565                                          bank);
 566                                 break;
 567                         }
 568                 }
 569                 for (ireg = 0; ireg < ec->nr_registers; ireg++) {
 570                         reg_bank = register_bank(ec->registers[ireg]);
 571                         if (reg_bank < bank) {
 572                                 continue;
 573                         }
 574                         ec_read(register_index(ec->registers[ireg]),
 575                                 ec->read_buffer + ireg);
 576                 }
 577         }
 578
 579         status = asus_ec_bank_switch(prev_bank, NULL);
 580         return status;
 581 }
 582
 583 static inline s32 get_sensor_value(const struct ec_sensor_info *si, u8 *data)
 584 {
 585         if (is_sensor_data_signed(si)) {
 586                 switch (si->addr.components.size) {
 587                 case 1:
 588                         return (s8)*data;
 589                 case 2:
 590                         return (s16)get_unaligned_be16(data);
 591                 case 4:
 592                         return (s32)get_unaligned_be32(data);
 593                 default:
 594                         return 0;
 595                 }
 596         } else {
 597                 switch (si->addr.components.size) {
 598                 case 1:
 599                         return *data;
 600                 case 2:
 601                         return get_unaligned_be16(data);
 602                 case 4:
 603                         return get_unaligned_be32(data);
 604                 default:
 605                         return 0;
 606                 }
 607         }
 608 }
 609
 610 static void update_sensor_values(struct ec_sensors_data *ec, u8 *data)
 611 {
 612         const struct ec_sensor_info *si;
 613         struct ec_sensor *s, *sensor_end;
 614
 615         sensor_end = ec->sensors + ec->nr_sensors;
 616         for (s = ec->sensors; s != sensor_end; s++) {
 617                 si = ec->sensors_info + s->info_index;
 618                 s->cached_value = get_sensor_value(si, data);
 619                 data += si->addr.components.size;
 620         }
 621 }
 622
 623 static int update_ec_sensors(const struct device *dev,
 624                              struct ec_sensors_data *ec)
 625 {
 626         int status;
 627
 628         if (!ec->lock_data.lock(&ec->lock_data)) {
 629                 dev_warn(dev, "Failed to acquire mutex");
 630                 return -EBUSY;
 631         }
 632
 633         status = asus_ec_block_read(dev, ec);
 634
 635         if (!status) {
 636                 update_sensor_values(ec, ec->read_buffer);
 637         }
 638
 639         if (!ec->lock_data.unlock(&ec->lock_data))
 640                 dev_err(dev, "Failed to release mutex");
 641
 642         return status;
 643 }
 644
 645 static long scale_sensor_value(s32 value, int data_type)
 646 {
 647         switch (data_type) {
 648         case hwmon_curr:
 649         case hwmon_temp:
 650                 return value * MILLI;
 651         default:
 652                 return value;
 653         }
 654 }
 655
 656 static int get_cached_value_or_update(const struct device *dev,
 657                                       int sensor_index,
 658                                       struct ec_sensors_data *state, s32 *value)
 659 {
 660         if (time_after(jiffies, state->last_updated + HZ)) {
 661                 if (update_ec_sensors(dev, state)) {
 662                         dev_err(dev, "update_ec_sensors() failure\n");
 663                         return -EIO;
 664                 }
 665
 666                 state->last_updated = jiffies;
 667         }
 668
 669         *value = state->sensors[sensor_index].cached_value;
 670         return 0;
 671 }
 672
 673 /*
 674  * Now follow the functions that implement the hwmon interface
 675  */
 676
 677 static int asus_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 678                               u32 attr, int channel, long *val)
 679 {
 680         int ret;
 681         s32 value = 0;
 682
 683         struct ec_sensors_data *state = dev_get_drvdata(dev);
 684         int sidx = find_ec_sensor_index(state, type, channel);
 685
 686         if (sidx < 0) {
 687                 return sidx;
 688         }
 689
 690         ret = get_cached_value_or_update(dev, sidx, state, &value);
 691         if (!ret) {
 692                 *val = scale_sensor_value(value,
 693                                           get_sensor_info(state, sidx)->type);
 694         }
 695
 696         return ret;
 697 }
 698
 699 static int asus_ec_hwmon_read_string(struct device *dev,
 700                                      enum hwmon_sensor_types type, u32 attr,
 701                                      int channel, const char **str)
 702 {
 703         struct ec_sensors_data *state = dev_get_drvdata(dev);
 704         int sensor_index = find_ec_sensor_index(state, type, channel);
 705         *str = get_sensor_info(state, sensor_index)->label;
 706
 707         return 0;
 708 }
 709
 710 static umode_t asus_ec_hwmon_is_visible(const void *drvdata,
 711                                         enum hwmon_sensor_types type, u32 attr,
 712                                         int channel)
 713 {
 714         const struct ec_sensors_data *state = drvdata;
 715
 716         return find_ec_sensor_index(state, type, channel) >= 0 ? S_IRUGO : 0;
 717 }
 718
 719 static int __init
 720 asus_ec_hwmon_add_chan_info(struct hwmon_channel_info *asus_ec_hwmon_chan,
 721                              struct device *dev, int num,
 722                              enum hwmon_sensor_types type, u32 config)
 723 {
 724         int i;
 725         u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);
 726
 727         if (!cfg)
 728                 return -ENOMEM;
 729
 730         asus_ec_hwmon_chan->type = type;
 731         asus_ec_hwmon_chan->config = cfg;
 732         for (i = 0; i < num; i++, cfg++)
 733                 *cfg = config;
 734
 735         return 0;
 736 }
 737
 738 static const struct hwmon_ops asus_ec_hwmon_ops = {
 739         .is_visible = asus_ec_hwmon_is_visible,
 740         .read = asus_ec_hwmon_read,
 741         .read_string = asus_ec_hwmon_read_string,
 742 };
 743
 744 static struct hwmon_chip_info asus_ec_chip_info = {
 745         .ops = &asus_ec_hwmon_ops,
 746 };
 747
 748 static const struct ec_board_info * __init get_board_info(void)
 749 {
 750         const char *dmi_board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
 751         const char *dmi_board_name = dmi_get_system_info(DMI_BOARD_NAME);
 752         const struct ec_board_info *board;
 753
 754         if (!dmi_board_vendor || !dmi_board_name ||
 755             strcasecmp(dmi_board_vendor, "ASUSTeK COMPUTER INC."))
 756                 return NULL;
 757
 758         for (board = board_info; board->sensors; board++) {
 759                 if (match_string(board->board_names,
 760                                  MAX_IDENTICAL_BOARD_VARIATIONS,
 761                                  dmi_board_name) >= 0)
 762                         return board;
 763         }
 764
 765         return NULL;
 766 }
 767
 768 static int __init asus_ec_probe(struct platform_device *pdev)
 769 {
 770         const struct hwmon_channel_info **ptr_asus_ec_ci;
 771         int nr_count[hwmon_max] = { 0 }, nr_types = 0;
 772         struct hwmon_channel_info *asus_ec_hwmon_chan;
 773         const struct ec_board_info *pboard_info;
 774         const struct hwmon_chip_info *chip_info;
 775         struct device *dev = &pdev->dev;
 776         struct ec_sensors_data *ec_data;
 777         const struct ec_sensor_info *si;
 778         enum hwmon_sensor_types type;
 779         struct device *hwdev;
 780         unsigned int i;
 781         int status;
 782
 783         pboard_info = get_board_info();
 784         if (!pboard_info)
 785                 return -ENODEV;
 786
 787         ec_data = devm_kzalloc(dev, sizeof(struct ec_sensors_data),
 788                                GFP_KERNEL);
 789         if (!ec_data)
 790                 return -ENOMEM;
 791
 792         dev_set_drvdata(dev, ec_data);
 793         ec_data->board_info = pboard_info;
 794
 795         switch (ec_data->board_info->family) {
 796         case family_amd_400_series:
 797                 ec_data->sensors_info = sensors_family_amd_400;
 798                 break;
 799         case family_amd_500_series:
 800                 ec_data->sensors_info = sensors_family_amd_500;
 801                 break;
 802         default:
 803                 dev_err(dev, "Unknown board family: %d",
 804                         ec_data->board_info->family);
 805                 return -EINVAL;
 806         }
 807
 808         ec_data->nr_sensors = hweight_long(ec_data->board_info->sensors);
 809         ec_data->sensors = devm_kcalloc(dev, ec_data->nr_sensors,
 810                                         sizeof(struct ec_sensor), GFP_KERNEL);
 811
 812         status = setup_lock_data(dev);
 813         if (status) {
 814                 dev_err(dev, "Failed to setup state/EC locking: %d", status);
 815                 return status;
 816         }
 817
 818         setup_sensor_data(ec_data);
 819         ec_data->registers = devm_kcalloc(dev, ec_data->nr_registers,
 820                                           sizeof(u16), GFP_KERNEL);
 821         ec_data->read_buffer = devm_kcalloc(dev, ec_data->nr_registers,
 822                                             sizeof(u8), GFP_KERNEL);
 823
 824         if (!ec_data->registers || !ec_data->read_buffer)
 825                 return -ENOMEM;
 826
 827         fill_ec_registers(ec_data);
 828
 829         for (i = 0; i < ec_data->nr_sensors; ++i) {
 830                 si = get_sensor_info(ec_data, i);
 831                 if (!nr_count[si->type])
 832                         ++nr_types;
 833                 ++nr_count[si->type];
 834         }
 835
 836         if (nr_count[hwmon_temp])
 837                 nr_count[hwmon_chip]++, nr_types++;
 838
 839         asus_ec_hwmon_chan = devm_kcalloc(
 840                 dev, nr_types, sizeof(*asus_ec_hwmon_chan), GFP_KERNEL);
 841         if (!asus_ec_hwmon_chan)
 842                 return -ENOMEM;
 843
 844         ptr_asus_ec_ci = devm_kcalloc(dev, nr_types + 1,
 845                                        sizeof(*ptr_asus_ec_ci), GFP_KERNEL);
 846         if (!ptr_asus_ec_ci)
 847                 return -ENOMEM;
 848
 849         asus_ec_chip_info.info = ptr_asus_ec_ci;
 850         chip_info = &asus_ec_chip_info;
 851
 852         for (type = 0; type < hwmon_max; ++type) {
 853                 if (!nr_count[type])
 854                         continue;
 855
 856                 asus_ec_hwmon_add_chan_info(asus_ec_hwmon_chan, dev,
 857                                              nr_count[type], type,
 858                                              hwmon_attributes[type]);
 859                 *ptr_asus_ec_ci++ = asus_ec_hwmon_chan++;
 860         }
 861
 862         dev_info(dev, "board has %d EC sensors that span %d registers",
 863                  ec_data->nr_sensors, ec_data->nr_registers);
 864
 865         hwdev = devm_hwmon_device_register_with_info(dev, "asusec",
 866                                                      ec_data, chip_info, NULL);
 867
 868         return PTR_ERR_OR_ZERO(hwdev);
 869 }
 870
 871
 872 static const struct acpi_device_id acpi_ec_ids[] = {
 873         /* Embedded Controller Device */
 874         { "PNP0C09", 0 },
 875         {}
 876 };
 877
 878 static struct platform_driver asus_ec_sensors_platform_driver = {
 879         .driver = {
 880                 .name   = "asus-ec-sensors",
 881                 .acpi_match_table = acpi_ec_ids,
 882         },
 883 };
 884
 885 MODULE_DEVICE_TABLE(acpi, acpi_ec_ids);
 886 /*
 887  * we use module_platform_driver_probe() rather than module_platform_driver()
 888  * because the probe function (and its dependants) are marked with __init, which
 889  * means we can't put it into the .probe member of the platform_driver struct
 890  * above, and we can't mark the asus_ec_sensors_platform_driver object as __init
 891  * because the object is referenced from the module exit code.
 892  */
 893 module_platform_driver_probe(asus_ec_sensors_platform_driver, asus_ec_probe);
 894
 895 module_param_named(mutex_path, mutex_path_override, charp, 0);
 896 MODULE_PARM_DESC(mutex_path,
 897                  "Override ACPI mutex path used to guard access to hardware");
 898
 899 MODULE_AUTHOR("Eugene Shalygin <eugene.shalygin@gmail.com>");
 900 MODULE_DESCRIPTION(
 901         "HWMON driver for sensors accessible via ACPI EC in ASUS motherboards");
 902 MODULE_LICENSE("GPL");