drivers/hwmon/xgene-hwmon.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * APM X-Gene SoC Hardware Monitoring Driver
   4  *
   5  * Copyright (c) 2016, Applied Micro Circuits Corporation
   6  * Author: Loc Ho <lho@apm.com>
   7  *         Hoan Tran <hotran@apm.com>
   8  *
   9  * This driver provides the following features:
  10  *  - Retrieve CPU total power (uW)
  11  *  - Retrieve IO total power (uW)
  12  *  - Retrieve SoC temperature (milli-degree C) and alarm
  13  */
  14 #include <linux/acpi.h>
  15 #include <linux/dma-mapping.h>
  16 #include <linux/hwmon.h>
  17 #include <linux/hwmon-sysfs.h>
  18 #include <linux/io.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kfifo.h>
  21 #include <linux/mailbox_controller.h>
  22 #include <linux/mailbox_client.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/platform_device.h>
  26
  27 #include <acpi/pcc.h>
  28
  29 /* SLIMpro message defines */
  30 #define MSG_TYPE_DBG                    0
  31 #define MSG_TYPE_ERR                    7
  32 #define MSG_TYPE_PWRMGMT                9
  33
  34 #define MSG_TYPE(v)                     (((v) & 0xF0000000) >> 28)
  35 #define MSG_TYPE_SET(v)                 (((v) << 28) & 0xF0000000)
  36 #define MSG_SUBTYPE(v)                  (((v) & 0x0F000000) >> 24)
  37 #define MSG_SUBTYPE_SET(v)              (((v) << 24) & 0x0F000000)
  38
  39 #define DBG_SUBTYPE_SENSOR_READ         4
  40 #define SENSOR_RD_MSG                   0x04FFE902
  41 #define SENSOR_RD_EN_ADDR(a)            ((a) & 0x000FFFFF)
  42 #define PMD_PWR_REG                     0x20
  43 #define PMD_PWR_MW_REG                  0x26
  44 #define SOC_PWR_REG                     0x21
  45 #define SOC_PWR_MW_REG                  0x27
  46 #define SOC_TEMP_REG                    0x10
  47
  48 #define TEMP_NEGATIVE_BIT               8
  49 #define SENSOR_INVALID_DATA             BIT(15)
  50
  51 #define PWRMGMT_SUBTYPE_TPC             1
  52 #define TPC_ALARM                       2
  53 #define TPC_GET_ALARM                   3
  54 #define TPC_CMD(v)                      (((v) & 0x00FF0000) >> 16)
  55 #define TPC_CMD_SET(v)                  (((v) << 16) & 0x00FF0000)
  56 #define TPC_EN_MSG(hndl, cmd, type) \
  57         (MSG_TYPE_SET(MSG_TYPE_PWRMGMT) | \
  58         MSG_SUBTYPE_SET(hndl) | TPC_CMD_SET(cmd) | type)
  59
  60 /* PCC defines */
  61 #define PCC_SIGNATURE_MASK              0x50424300
  62 #define PCCC_GENERATE_DB_INT            BIT(15)
  63 #define PCCS_CMD_COMPLETE               BIT(0)
  64 #define PCCS_SCI_DOORBEL                BIT(1)
  65 #define PCCS_PLATFORM_NOTIFICATION      BIT(3)
  66 /*
  67  * Arbitrary retries in case the remote processor is slow to respond
  68  * to PCC commands
  69  */
  70 #define PCC_NUM_RETRIES                 500
  71
  72 #define ASYNC_MSG_FIFO_SIZE             16
  73 #define MBOX_OP_TIMEOUTMS               1000
  74
  75 #define WATT_TO_mWATT(x)                ((x) * 1000)
  76 #define mWATT_TO_uWATT(x)               ((x) * 1000)
  77 #define CELSIUS_TO_mCELSIUS(x)          ((x) * 1000)
  78
  79 #define to_xgene_hwmon_dev(cl)          \
  80         container_of(cl, struct xgene_hwmon_dev, mbox_client)
  81
  82 enum xgene_hwmon_version {
  83         XGENE_HWMON_V1 = 0,
  84         XGENE_HWMON_V2 = 1,
  85 };
  86
  87 struct slimpro_resp_msg {
  88         u32 msg;
  89         u32 param1;
  90         u32 param2;
  91 } __packed;
  92
  93 struct xgene_hwmon_dev {
  94         struct device           *dev;
  95         struct mbox_chan        *mbox_chan;
  96         struct mbox_client      mbox_client;
  97         int                     mbox_idx;
  98
  99         spinlock_t              kfifo_lock;
 100         struct mutex            rd_mutex;
 101         struct completion       rd_complete;
 102         int                     resp_pending;
 103         struct slimpro_resp_msg sync_msg;
 104
 105         struct work_struct      workq;
 106         struct kfifo_rec_ptr_1  async_msg_fifo;
 107
 108         struct device           *hwmon_dev;
 109         bool                    temp_critical_alarm;
 110
 111         phys_addr_t             comm_base_addr;
 112         void                    *pcc_comm_addr;
 113         u64                     usecs_lat;
 114 };
 115
 116 /*
 117  * This function tests and clears a bitmask then returns its old value
 118  */
 119 static u16 xgene_word_tst_and_clr(u16 *addr, u16 mask)
 120 {
 121         u16 ret, val;
 122
 123         val = le16_to_cpu(READ_ONCE(*addr));
 124         ret = val & mask;
 125         val &= ~mask;
 126         WRITE_ONCE(*addr, cpu_to_le16(val));
 127
 128         return ret;
 129 }
 130
 131 static int xgene_hwmon_pcc_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
 132 {
 133         struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
 134         u32 *ptr = (void *)(generic_comm_base + 1);
 135         int rc, i;
 136         u16 val;
 137
 138         mutex_lock(&ctx->rd_mutex);
 139         init_completion(&ctx->rd_complete);
 140         ctx->resp_pending = true;
 141
 142         /* Write signature for subspace */
 143         WRITE_ONCE(generic_comm_base->signature,
 144                    cpu_to_le32(PCC_SIGNATURE_MASK | ctx->mbox_idx));
 145
 146         /* Write to the shared command region */
 147         WRITE_ONCE(generic_comm_base->command,
 148                    cpu_to_le16(MSG_TYPE(msg[0]) | PCCC_GENERATE_DB_INT));
 149
 150         /* Flip CMD COMPLETE bit */
 151         val = le16_to_cpu(READ_ONCE(generic_comm_base->status));
 152         val &= ~PCCS_CMD_COMPLETE;
 153         WRITE_ONCE(generic_comm_base->status, cpu_to_le16(val));
 154
 155         /* Copy the message to the PCC comm space */
 156         for (i = 0; i < sizeof(struct slimpro_resp_msg) / 4; i++)
 157                 WRITE_ONCE(ptr[i], cpu_to_le32(msg[i]));
 158
 159         /* Ring the doorbell */
 160         rc = mbox_send_message(ctx->mbox_chan, msg);
 161         if (rc < 0) {
 162                 dev_err(ctx->dev, "Mailbox send error %d\n", rc);
 163                 goto err;
 164         }
 165         if (!wait_for_completion_timeout(&ctx->rd_complete,
 166                                          usecs_to_jiffies(ctx->usecs_lat))) {
 167                 dev_err(ctx->dev, "Mailbox operation timed out\n");
 168                 rc = -ETIMEDOUT;
 169                 goto err;
 170         }
 171
 172         /* Check for error message */
 173         if (MSG_TYPE(ctx->sync_msg.msg) == MSG_TYPE_ERR) {
 174                 rc = -EINVAL;
 175                 goto err;
 176         }
 177
 178         msg[0] = ctx->sync_msg.msg;
 179         msg[1] = ctx->sync_msg.param1;
 180         msg[2] = ctx->sync_msg.param2;
 181
 182 err:
 183         mbox_chan_txdone(ctx->mbox_chan, 0);
 184         ctx->resp_pending = false;
 185         mutex_unlock(&ctx->rd_mutex);
 186         return rc;
 187 }
 188
 189 static int xgene_hwmon_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
 190 {
 191         int rc;
 192
 193         mutex_lock(&ctx->rd_mutex);
 194         init_completion(&ctx->rd_complete);
 195         ctx->resp_pending = true;
 196
 197         rc = mbox_send_message(ctx->mbox_chan, msg);
 198         if (rc < 0) {
 199                 dev_err(ctx->dev, "Mailbox send error %d\n", rc);
 200                 goto err;
 201         }
 202
 203         if (!wait_for_completion_timeout(&ctx->rd_complete,
 204                                          msecs_to_jiffies(MBOX_OP_TIMEOUTMS))) {
 205                 dev_err(ctx->dev, "Mailbox operation timed out\n");
 206                 rc = -ETIMEDOUT;
 207                 goto err;
 208         }
 209
 210         /* Check for error message */
 211         if (MSG_TYPE(ctx->sync_msg.msg) == MSG_TYPE_ERR) {
 212                 rc = -EINVAL;
 213                 goto err;
 214         }
 215
 216         msg[0] = ctx->sync_msg.msg;
 217         msg[1] = ctx->sync_msg.param1;
 218         msg[2] = ctx->sync_msg.param2;
 219
 220 err:
 221         ctx->resp_pending = false;
 222         mutex_unlock(&ctx->rd_mutex);
 223         return rc;
 224 }
 225
 226 static int xgene_hwmon_reg_map_rd(struct xgene_hwmon_dev *ctx, u32 addr,
 227                                   u32 *data)
 228 {
 229         u32 msg[3];
 230         int rc;
 231
 232         msg[0] = SENSOR_RD_MSG;
 233         msg[1] = SENSOR_RD_EN_ADDR(addr);
 234         msg[2] = 0;
 235
 236         if (acpi_disabled)
 237                 rc = xgene_hwmon_rd(ctx, msg);
 238         else
 239                 rc = xgene_hwmon_pcc_rd(ctx, msg);
 240
 241         if (rc < 0)
 242                 return rc;
 243
 244         /*
 245          * Check if sensor data is valid.
 246          */
 247         if (msg[1] & SENSOR_INVALID_DATA)
 248                 return -ENODATA;
 249
 250         *data = msg[1];
 251
 252         return rc;
 253 }
 254
 255 static int xgene_hwmon_get_notification_msg(struct xgene_hwmon_dev *ctx,
 256                                             u32 *amsg)
 257 {
 258         u32 msg[3];
 259         int rc;
 260
 261         msg[0] = TPC_EN_MSG(PWRMGMT_SUBTYPE_TPC, TPC_GET_ALARM, 0);
 262         msg[1] = 0;
 263         msg[2] = 0;
 264
 265         rc = xgene_hwmon_pcc_rd(ctx, msg);
 266         if (rc < 0)
 267                 return rc;
 268
 269         amsg[0] = msg[0];
 270         amsg[1] = msg[1];
 271         amsg[2] = msg[2];
 272
 273         return rc;
 274 }
 275
 276 static int xgene_hwmon_get_cpu_pwr(struct xgene_hwmon_dev *ctx, u32 *val)
 277 {
 278         u32 watt, mwatt;
 279         int rc;
 280
 281         rc = xgene_hwmon_reg_map_rd(ctx, PMD_PWR_REG, &watt);
 282         if (rc < 0)
 283                 return rc;
 284
 285         rc = xgene_hwmon_reg_map_rd(ctx, PMD_PWR_MW_REG, &mwatt);
 286         if (rc < 0)
 287                 return rc;
 288
 289         *val = WATT_TO_mWATT(watt) + mwatt;
 290         return 0;
 291 }
 292
 293 static int xgene_hwmon_get_io_pwr(struct xgene_hwmon_dev *ctx, u32 *val)
 294 {
 295         u32 watt, mwatt;
 296         int rc;
 297
 298         rc = xgene_hwmon_reg_map_rd(ctx, SOC_PWR_REG, &watt);
 299         if (rc < 0)
 300                 return rc;
 301
 302         rc = xgene_hwmon_reg_map_rd(ctx, SOC_PWR_MW_REG, &mwatt);
 303         if (rc < 0)
 304                 return rc;
 305
 306         *val = WATT_TO_mWATT(watt) + mwatt;
 307         return 0;
 308 }
 309
 310 static int xgene_hwmon_get_temp(struct xgene_hwmon_dev *ctx, u32 *val)
 311 {
 312         return xgene_hwmon_reg_map_rd(ctx, SOC_TEMP_REG, val);
 313 }
 314
 315 /*
 316  * Sensor temperature/power functions
 317  */
 318 static ssize_t temp1_input_show(struct device *dev,
 319                                 struct device_attribute *attr,
 320                                 char *buf)
 321 {
 322         struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
 323         int rc, temp;
 324         u32 val;
 325
 326         rc = xgene_hwmon_get_temp(ctx, &val);
 327         if (rc < 0)
 328                 return rc;
 329
 330         temp = sign_extend32(val, TEMP_NEGATIVE_BIT);
 331
 332         return snprintf(buf, PAGE_SIZE, "%d\n", CELSIUS_TO_mCELSIUS(temp));
 333 }
 334
 335 static ssize_t temp1_label_show(struct device *dev,
 336                                 struct device_attribute *attr,
 337                                 char *buf)
 338 {
 339         return snprintf(buf, PAGE_SIZE, "SoC Temperature\n");
 340 }
 341
 342 static ssize_t temp1_critical_alarm_show(struct device *dev,
 343                                          struct device_attribute *devattr,
 344                                          char *buf)
 345 {
 346         struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
 347
 348         return snprintf(buf, PAGE_SIZE, "%d\n", ctx->temp_critical_alarm);
 349 }
 350
 351 static ssize_t power1_label_show(struct device *dev,
 352                                  struct device_attribute *attr,
 353                                  char *buf)
 354 {
 355         return snprintf(buf, PAGE_SIZE, "CPU power\n");
 356 }
 357
 358 static ssize_t power2_label_show(struct device *dev,
 359                                  struct device_attribute *attr,
 360                                  char *buf)
 361 {
 362         return snprintf(buf, PAGE_SIZE, "IO power\n");
 363 }
 364
 365 static ssize_t power1_input_show(struct device *dev,
 366                                  struct device_attribute *attr,
 367                                  char *buf)
 368 {
 369         struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
 370         u32 val;
 371         int rc;
 372
 373         rc = xgene_hwmon_get_cpu_pwr(ctx, &val);
 374         if (rc < 0)
 375                 return rc;
 376
 377         return snprintf(buf, PAGE_SIZE, "%u\n", mWATT_TO_uWATT(val));
 378 }
 379
 380 static ssize_t power2_input_show(struct device *dev,
 381                                  struct device_attribute *attr,
 382                                  char *buf)
 383 {
 384         struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
 385         u32 val;
 386         int rc;
 387
 388         rc = xgene_hwmon_get_io_pwr(ctx, &val);
 389         if (rc < 0)
 390                 return rc;
 391
 392         return snprintf(buf, PAGE_SIZE, "%u\n", mWATT_TO_uWATT(val));
 393 }
 394
 395 static DEVICE_ATTR_RO(temp1_label);
 396 static DEVICE_ATTR_RO(temp1_input);
 397 static DEVICE_ATTR_RO(temp1_critical_alarm);
 398 static DEVICE_ATTR_RO(power1_label);
 399 static DEVICE_ATTR_RO(power1_input);
 400 static DEVICE_ATTR_RO(power2_label);
 401 static DEVICE_ATTR_RO(power2_input);
 402
 403 static struct attribute *xgene_hwmon_attrs[] = {
 404         &dev_attr_temp1_label.attr,
 405         &dev_attr_temp1_input.attr,
 406         &dev_attr_temp1_critical_alarm.attr,
 407         &dev_attr_power1_label.attr,
 408         &dev_attr_power1_input.attr,
 409         &dev_attr_power2_label.attr,
 410         &dev_attr_power2_input.attr,
 411         NULL,
 412 };
 413
 414 ATTRIBUTE_GROUPS(xgene_hwmon);
 415
 416 static int xgene_hwmon_tpc_alarm(struct xgene_hwmon_dev *ctx,
 417                                  struct slimpro_resp_msg *amsg)
 418 {
 419         ctx->temp_critical_alarm = !!amsg->param2;
 420         sysfs_notify(&ctx->dev->kobj, NULL, "temp1_critical_alarm");
 421
 422         return 0;
 423 }
 424
 425 static void xgene_hwmon_process_pwrmsg(struct xgene_hwmon_dev *ctx,
 426                                        struct slimpro_resp_msg *amsg)
 427 {
 428         if ((MSG_SUBTYPE(amsg->msg) == PWRMGMT_SUBTYPE_TPC) &&
 429             (TPC_CMD(amsg->msg) == TPC_ALARM))
 430                 xgene_hwmon_tpc_alarm(ctx, amsg);
 431 }
 432
 433 /*
 434  * This function is called to process async work queue
 435  */
 436 static void xgene_hwmon_evt_work(struct work_struct *work)
 437 {
 438         struct slimpro_resp_msg amsg;
 439         struct xgene_hwmon_dev *ctx;
 440         int ret;
 441
 442         ctx = container_of(work, struct xgene_hwmon_dev, workq);
 443         while (kfifo_out_spinlocked(&ctx->async_msg_fifo, &amsg,
 444                                     sizeof(struct slimpro_resp_msg),
 445                                     &ctx->kfifo_lock)) {
 446                 /*
 447                  * If PCC, send a consumer command to Platform to get info
 448                  * If Slimpro Mailbox, get message from specific FIFO
 449                  */
 450                 if (!acpi_disabled) {
 451                         ret = xgene_hwmon_get_notification_msg(ctx,
 452                                                                (u32 *)&amsg);
 453                         if (ret < 0)
 454                                 continue;
 455                 }
 456
 457                 if (MSG_TYPE(amsg.msg) == MSG_TYPE_PWRMGMT)
 458                         xgene_hwmon_process_pwrmsg(ctx, &amsg);
 459         }
 460 }
 461
 462 static int xgene_hwmon_rx_ready(struct xgene_hwmon_dev *ctx, void *msg)
 463 {
 464         if (IS_ERR_OR_NULL(ctx->hwmon_dev) && !ctx->resp_pending) {
 465                 /* Enqueue to the FIFO */
 466                 kfifo_in_spinlocked(&ctx->async_msg_fifo, msg,
 467                                     sizeof(struct slimpro_resp_msg),
 468                                     &ctx->kfifo_lock);
 469                 return -ENODEV;
 470         }
 471
 472         return 0;
 473 }
 474
 475 /*
 476  * This function is called when the SLIMpro Mailbox received a message
 477  */
 478 static void xgene_hwmon_rx_cb(struct mbox_client *cl, void *msg)
 479 {
 480         struct xgene_hwmon_dev *ctx = to_xgene_hwmon_dev(cl);
 481
 482         /*
 483          * While the driver registers with the mailbox framework, an interrupt
 484          * can be pending before the probe function completes its
 485          * initialization. If such condition occurs, just queue up the message
 486          * as the driver is not ready for servicing the callback.
 487          */
 488         if (xgene_hwmon_rx_ready(ctx, msg) < 0)
 489                 return;
 490
 491         /*
 492          * Response message format:
 493          * msg[0] is the return code of the operation
 494          * msg[1] is the first parameter word
 495          * msg[2] is the second parameter word
 496          *
 497          * As message only supports dword size, just assign it.
 498          */
 499
 500         /* Check for sync query */
 501         if (ctx->resp_pending &&
 502             ((MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_ERR) ||
 503              (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_DBG &&
 504               MSG_SUBTYPE(((u32 *)msg)[0]) == DBG_SUBTYPE_SENSOR_READ) ||
 505              (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_PWRMGMT &&
 506               MSG_SUBTYPE(((u32 *)msg)[0]) == PWRMGMT_SUBTYPE_TPC &&
 507               TPC_CMD(((u32 *)msg)[0]) == TPC_ALARM))) {
 508                 ctx->sync_msg.msg = ((u32 *)msg)[0];
 509                 ctx->sync_msg.param1 = ((u32 *)msg)[1];
 510                 ctx->sync_msg.param2 = ((u32 *)msg)[2];
 511
 512                 /* Operation waiting for response */
 513                 complete(&ctx->rd_complete);
 514
 515                 return;
 516         }
 517
 518         /* Enqueue to the FIFO */
 519         kfifo_in_spinlocked(&ctx->async_msg_fifo, msg,
 520                             sizeof(struct slimpro_resp_msg), &ctx->kfifo_lock);
 521         /* Schedule the bottom handler */
 522         schedule_work(&ctx->workq);
 523 }
 524
 525 /*
 526  * This function is called when the PCC Mailbox received a message
 527  */
 528 static void xgene_hwmon_pcc_rx_cb(struct mbox_client *cl, void *msg)
 529 {
 530         struct xgene_hwmon_dev *ctx = to_xgene_hwmon_dev(cl);
 531         struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
 532         struct slimpro_resp_msg amsg;
 533
 534         /*
 535          * While the driver registers with the mailbox framework, an interrupt
 536          * can be pending before the probe function completes its
 537          * initialization. If such condition occurs, just queue up the message
 538          * as the driver is not ready for servicing the callback.
 539          */
 540         if (xgene_hwmon_rx_ready(ctx, &amsg) < 0)
 541                 return;
 542
 543         msg = generic_comm_base + 1;
 544         /* Check if platform sends interrupt */
 545         if (!xgene_word_tst_and_clr(&generic_comm_base->status,
 546                                     PCCS_SCI_DOORBEL))
 547                 return;
 548
 549         /*
 550          * Response message format:
 551          * msg[0] is the return code of the operation
 552          * msg[1] is the first parameter word
 553          * msg[2] is the second parameter word
 554          *
 555          * As message only supports dword size, just assign it.
 556          */
 557
 558         /* Check for sync query */
 559         if (ctx->resp_pending &&
 560             ((MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_ERR) ||
 561              (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_DBG &&
 562               MSG_SUBTYPE(((u32 *)msg)[0]) == DBG_SUBTYPE_SENSOR_READ) ||
 563              (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_PWRMGMT &&
 564               MSG_SUBTYPE(((u32 *)msg)[0]) == PWRMGMT_SUBTYPE_TPC &&
 565               TPC_CMD(((u32 *)msg)[0]) == TPC_ALARM))) {
 566                 /* Check if platform completes command */
 567                 if (xgene_word_tst_and_clr(&generic_comm_base->status,
 568                                            PCCS_CMD_COMPLETE)) {
 569                         ctx->sync_msg.msg = ((u32 *)msg)[0];
 570                         ctx->sync_msg.param1 = ((u32 *)msg)[1];
 571                         ctx->sync_msg.param2 = ((u32 *)msg)[2];
 572
 573                         /* Operation waiting for response */
 574                         complete(&ctx->rd_complete);
 575
 576                         return;
 577                 }
 578         }
 579
 580         /*
 581          * Platform notifies interrupt to OSPM.
 582          * OPSM schedules a consumer command to get this information
 583          * in a workqueue. Platform must wait until OSPM has issued
 584          * a consumer command that serves this notification.
 585          */
 586
 587         /* Enqueue to the FIFO */
 588         kfifo_in_spinlocked(&ctx->async_msg_fifo, &amsg,
 589                             sizeof(struct slimpro_resp_msg), &ctx->kfifo_lock);
 590         /* Schedule the bottom handler */
 591         schedule_work(&ctx->workq);
 592 }
 593
 594 static void xgene_hwmon_tx_done(struct mbox_client *cl, void *msg, int ret)
 595 {
 596         if (ret) {
 597                 dev_dbg(cl->dev, "TX did not complete: CMD sent:%x, ret:%d\n",
 598                         *(u16 *)msg, ret);
 599         } else {
 600                 dev_dbg(cl->dev, "TX completed. CMD sent:%x, ret:%d\n",
 601                         *(u16 *)msg, ret);
 602         }
 603 }
 604
 605 #ifdef CONFIG_ACPI
 606 static const struct acpi_device_id xgene_hwmon_acpi_match[] = {
 607         {"APMC0D29", XGENE_HWMON_V1},
 608         {"APMC0D8A", XGENE_HWMON_V2},
 609         {},
 610 };
 611 MODULE_DEVICE_TABLE(acpi, xgene_hwmon_acpi_match);
 612 #endif
 613
 614 static int xgene_hwmon_probe(struct platform_device *pdev)
 615 {
 616         struct xgene_hwmon_dev *ctx;
 617         struct mbox_client *cl;
 618         int rc;
 619
 620         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
 621         if (!ctx)
 622                 return -ENOMEM;
 623
 624         ctx->dev = &pdev->dev;
 625         platform_set_drvdata(pdev, ctx);
 626         cl = &ctx->mbox_client;
 627
 628         spin_lock_init(&ctx->kfifo_lock);
 629         mutex_init(&ctx->rd_mutex);
 630
 631         rc = kfifo_alloc(&ctx->async_msg_fifo,
 632                          sizeof(struct slimpro_resp_msg) * ASYNC_MSG_FIFO_SIZE,
 633                          GFP_KERNEL);
 634         if (rc)
 635                 return -ENOMEM;
 636
 637         INIT_WORK(&ctx->workq, xgene_hwmon_evt_work);
 638
 639         /* Request mailbox channel */
 640         cl->dev = &pdev->dev;
 641         cl->tx_done = xgene_hwmon_tx_done;
 642         cl->tx_block = false;
 643         cl->tx_tout = MBOX_OP_TIMEOUTMS;
 644         cl->knows_txdone = false;
 645         if (acpi_disabled) {
 646                 cl->rx_callback = xgene_hwmon_rx_cb;
 647                 ctx->mbox_chan = mbox_request_channel(cl, 0);
 648                 if (IS_ERR(ctx->mbox_chan)) {
 649                         dev_err(&pdev->dev,
 650                                 "SLIMpro mailbox channel request failed\n");
 651                         rc = -ENODEV;
 652                         goto out_mbox_free;
 653                 }
 654         } else {
 655                 struct acpi_pcct_hw_reduced *cppc_ss;
 656                 const struct acpi_device_id *acpi_id;
 657                 int version;
 658
 659                 acpi_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
 660                                             &pdev->dev);
 661                 if (!acpi_id)
 662                         return -EINVAL;
 663
 664                 version = (int)acpi_id->driver_data;
 665
 666                 if (device_property_read_u32(&pdev->dev, "pcc-channel",
 667                                              &ctx->mbox_idx)) {
 668                         dev_err(&pdev->dev, "no pcc-channel property\n");
 669                         rc = -ENODEV;
 670                         goto out_mbox_free;
 671                 }
 672
 673                 cl->rx_callback = xgene_hwmon_pcc_rx_cb;
 674                 ctx->mbox_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
 675                 if (IS_ERR(ctx->mbox_chan)) {
 676                         dev_err(&pdev->dev,
 677                                 "PPC channel request failed\n");
 678                         rc = -ENODEV;
 679                         goto out_mbox_free;
 680                 }
 681
 682                 /*
 683                  * The PCC mailbox controller driver should
 684                  * have parsed the PCCT (global table of all
 685                  * PCC channels) and stored pointers to the
 686                  * subspace communication region in con_priv.
 687                  */
 688                 cppc_ss = ctx->mbox_chan->con_priv;
 689                 if (!cppc_ss) {
 690                         dev_err(&pdev->dev, "PPC subspace not found\n");
 691                         rc = -ENODEV;
 692                         goto out;
 693                 }
 694
 695                 if (!ctx->mbox_chan->mbox->txdone_irq) {
 696                         dev_err(&pdev->dev, "PCC IRQ not supported\n");
 697                         rc = -ENODEV;
 698                         goto out;
 699                 }
 700
 701                 /*
 702                  * This is the shared communication region
 703                  * for the OS and Platform to communicate over.
 704                  */
 705                 ctx->comm_base_addr = cppc_ss->base_address;
 706                 if (ctx->comm_base_addr) {
 707                         if (version == XGENE_HWMON_V2)
 708                                 ctx->pcc_comm_addr = (void __force *)ioremap(
 709                                                         ctx->comm_base_addr,
 710                                                         cppc_ss->length);
 711                         else
 712                                 ctx->pcc_comm_addr = memremap(
 713                                                         ctx->comm_base_addr,
 714                                                         cppc_ss->length,
 715                                                         MEMREMAP_WB);
 716                 } else {
 717                         dev_err(&pdev->dev, "Failed to get PCC comm region\n");
 718                         rc = -ENODEV;
 719                         goto out;
 720                 }
 721
 722                 if (!ctx->pcc_comm_addr) {
 723                         dev_err(&pdev->dev,
 724                                 "Failed to ioremap PCC comm region\n");
 725                         rc = -ENOMEM;
 726                         goto out;
 727                 }
 728
 729                 /*
 730                  * cppc_ss->latency is just a Nominal value. In reality
 731                  * the remote processor could be much slower to reply.
 732                  * So add an arbitrary amount of wait on top of Nominal.
 733                  */
 734                 ctx->usecs_lat = PCC_NUM_RETRIES * cppc_ss->latency;
 735         }
 736
 737         ctx->hwmon_dev = hwmon_device_register_with_groups(ctx->dev,
 738                                                            "apm_xgene",
 739                                                            ctx,
 740                                                            xgene_hwmon_groups);
 741         if (IS_ERR(ctx->hwmon_dev)) {
 742                 dev_err(&pdev->dev, "Failed to register HW monitor device\n");
 743                 rc = PTR_ERR(ctx->hwmon_dev);
 744                 goto out;
 745         }
 746
 747         /*
 748          * Schedule the bottom handler if there is a pending message.
 749          */
 750         schedule_work(&ctx->workq);
 751
 752         dev_info(&pdev->dev, "APM X-Gene SoC HW monitor driver registered\n");
 753
 754         return 0;
 755
 756 out:
 757         if (acpi_disabled)
 758                 mbox_free_channel(ctx->mbox_chan);
 759         else
 760                 pcc_mbox_free_channel(ctx->mbox_chan);
 761 out_mbox_free:
 762         kfifo_free(&ctx->async_msg_fifo);
 763
 764         return rc;
 765 }
 766
 767 static int xgene_hwmon_remove(struct platform_device *pdev)
 768 {
 769         struct xgene_hwmon_dev *ctx = platform_get_drvdata(pdev);
 770
 771         hwmon_device_unregister(ctx->hwmon_dev);
 772         kfifo_free(&ctx->async_msg_fifo);
 773         if (acpi_disabled)
 774                 mbox_free_channel(ctx->mbox_chan);
 775         else
 776                 pcc_mbox_free_channel(ctx->mbox_chan);
 777
 778         return 0;
 779 }
 780
 781 static const struct of_device_id xgene_hwmon_of_match[] = {
 782         {.compatible = "apm,xgene-slimpro-hwmon"},
 783         {}
 784 };
 785 MODULE_DEVICE_TABLE(of, xgene_hwmon_of_match);
 786
 787 static struct platform_driver xgene_hwmon_driver __refdata = {
 788         .probe = xgene_hwmon_probe,
 789         .remove = xgene_hwmon_remove,
 790         .driver = {
 791                 .name = "xgene-slimpro-hwmon",
 792                 .of_match_table = xgene_hwmon_of_match,
 793                 .acpi_match_table = ACPI_PTR(xgene_hwmon_acpi_match),
 794         },
 795 };
 796 module_platform_driver(xgene_hwmon_driver);
 797
 798 MODULE_DESCRIPTION("APM X-Gene SoC hardware monitor");
 799 MODULE_LICENSE("GPL");