drivers/char/tpm/tpm_crb.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation
   3  *
   4  * Authors:
   5  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
   6  *
   7  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
   8  *
   9  * This device driver implements the TPM interface as defined in
  10  * the TCG CRB 2.0 TPM specification.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; version 2
  15  * of the License.
  16  */
  17
  18 #include <linux/acpi.h>
  19 #include <linux/highmem.h>
  20 #include <linux/rculist.h>
  21 #include <linux/module.h>
  22 #include <linux/pm_runtime.h>
  23 #ifdef CONFIG_ARM64
  24 #include <linux/arm-smccc.h>
  25 #endif
  26 #include "tpm.h"
  27
  28 #define ACPI_SIG_TPM2 "TPM2"
  29
  30 static const guid_t crb_acpi_start_guid =
  31         GUID_INIT(0x6BBF6CAB, 0x5463, 0x4714,
  32                   0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4);
  33
  34 enum crb_defaults {
  35         CRB_ACPI_START_REVISION_ID = 1,
  36         CRB_ACPI_START_INDEX = 1,
  37 };
  38
  39 enum crb_loc_ctrl {
  40         CRB_LOC_CTRL_REQUEST_ACCESS     = BIT(0),
  41         CRB_LOC_CTRL_RELINQUISH         = BIT(1),
  42 };
  43
  44 enum crb_loc_state {
  45         CRB_LOC_STATE_LOC_ASSIGNED      = BIT(1),
  46         CRB_LOC_STATE_TPM_REG_VALID_STS = BIT(7),
  47 };
  48
  49 enum crb_ctrl_req {
  50         CRB_CTRL_REQ_CMD_READY  = BIT(0),
  51         CRB_CTRL_REQ_GO_IDLE    = BIT(1),
  52 };
  53
  54 enum crb_ctrl_sts {
  55         CRB_CTRL_STS_ERROR      = BIT(0),
  56         CRB_CTRL_STS_TPM_IDLE   = BIT(1),
  57 };
  58
  59 enum crb_start {
  60         CRB_START_INVOKE        = BIT(0),
  61 };
  62
  63 enum crb_cancel {
  64         CRB_CANCEL_INVOKE       = BIT(0),
  65 };
  66
  67 struct crb_regs_head {
  68         u32 loc_state;
  69         u32 reserved1;
  70         u32 loc_ctrl;
  71         u32 loc_sts;
  72         u8 reserved2[32];
  73         u64 intf_id;
  74         u64 ctrl_ext;
  75 } __packed;
  76
  77 struct crb_regs_tail {
  78         u32 ctrl_req;
  79         u32 ctrl_sts;
  80         u32 ctrl_cancel;
  81         u32 ctrl_start;
  82         u32 ctrl_int_enable;
  83         u32 ctrl_int_sts;
  84         u32 ctrl_cmd_size;
  85         u32 ctrl_cmd_pa_low;
  86         u32 ctrl_cmd_pa_high;
  87         u32 ctrl_rsp_size;
  88         u64 ctrl_rsp_pa;
  89 } __packed;
  90
  91 enum crb_status {
  92         CRB_DRV_STS_COMPLETE    = BIT(0),
  93 };
  94
  95 struct crb_priv {
  96         u32 sm;
  97         const char *hid;
  98         void __iomem *iobase;
  99         struct crb_regs_head __iomem *regs_h;
 100         struct crb_regs_tail __iomem *regs_t;
 101         u8 __iomem *cmd;
 102         u8 __iomem *rsp;
 103         u32 cmd_size;
 104         u32 smc_func_id;
 105 };
 106
 107 struct tpm2_crb_smc {
 108         u32 interrupt;
 109         u8 interrupt_flags;
 110         u8 op_flags;
 111         u16 reserved2;
 112         u32 smc_func_id;
 113 };
 114
 115 /**
 116  * crb_go_idle - request tpm crb device to go the idle state
 117  *
 118  * @dev:  crb device
 119  * @priv: crb private data
 120  *
 121  * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
 122  * The device should respond within TIMEOUT_C by clearing the bit.
 123  * Anyhow, we do not wait here as a consequent CMD_READY request
 124  * will be handled correctly even if idle was not completed.
 125  *
 126  * The function does nothing for devices with ACPI-start method
 127  * or SMC-start method.
 128  *
 129  * Return: 0 always
 130  */
 131 static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
 132 {
 133         if ((priv->sm == ACPI_TPM2_START_METHOD) ||
 134             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
 135             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
 136                 return 0;
 137
 138         iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
 139         /* we don't really care when this settles */
 140
 141         return 0;
 142 }
 143
 144 static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
 145                                 unsigned long timeout)
 146 {
 147         ktime_t start;
 148         ktime_t stop;
 149
 150         start = ktime_get();
 151         stop = ktime_add(start, ms_to_ktime(timeout));
 152
 153         do {
 154                 if ((ioread32(reg) & mask) == value)
 155                         return true;
 156
 157                 usleep_range(50, 100);
 158         } while (ktime_before(ktime_get(), stop));
 159
 160         return false;
 161 }
 162
 163 /**
 164  * crb_cmd_ready - request tpm crb device to enter ready state
 165  *
 166  * @dev:  crb device
 167  * @priv: crb private data
 168  *
 169  * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
 170  * and poll till the device acknowledge it by clearing the bit.
 171  * The device should respond within TIMEOUT_C.
 172  *
 173  * The function does nothing for devices with ACPI-start method
 174  * or SMC-start method.
 175  *
 176  * Return: 0 on success -ETIME on timeout;
 177  */
 178 static int __maybe_unused crb_cmd_ready(struct device *dev,
 179                                         struct crb_priv *priv)
 180 {
 181         if ((priv->sm == ACPI_TPM2_START_METHOD) ||
 182             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
 183             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
 184                 return 0;
 185
 186         iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
 187         if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
 188                                  CRB_CTRL_REQ_CMD_READY /* mask */,
 189                                  0, /* value */
 190                                  TPM2_TIMEOUT_C)) {
 191                 dev_warn(dev, "cmdReady timed out\n");
 192                 return -ETIME;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static int crb_request_locality(struct tpm_chip *chip, int loc)
 199 {
 200         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 201         u32 value = CRB_LOC_STATE_LOC_ASSIGNED |
 202                 CRB_LOC_STATE_TPM_REG_VALID_STS;
 203
 204         if (!priv->regs_h)
 205                 return 0;
 206
 207         iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
 208         if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value,
 209                                  TPM2_TIMEOUT_C)) {
 210                 dev_warn(&chip->dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
 211                 return -ETIME;
 212         }
 213
 214         return 0;
 215 }
 216
 217 static void crb_relinquish_locality(struct tpm_chip *chip, int loc)
 218 {
 219         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 220
 221         if (!priv->regs_h)
 222                 return;
 223
 224         iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
 225 }
 226
 227 static u8 crb_status(struct tpm_chip *chip)
 228 {
 229         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 230         u8 sts = 0;
 231
 232         if ((ioread32(&priv->regs_t->ctrl_start) & CRB_START_INVOKE) !=
 233             CRB_START_INVOKE)
 234                 sts |= CRB_DRV_STS_COMPLETE;
 235
 236         return sts;
 237 }
 238
 239 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 240 {
 241         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 242         unsigned int expected;
 243
 244         /* sanity check */
 245         if (count < 6)
 246                 return -EIO;
 247
 248         if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
 249                 return -EIO;
 250
 251         memcpy_fromio(buf, priv->rsp, 6);
 252         expected = be32_to_cpup((__be32 *) &buf[2]);
 253         if (expected > count || expected < 6)
 254                 return -EIO;
 255
 256         memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
 257
 258         return expected;
 259 }
 260
 261 static int crb_do_acpi_start(struct tpm_chip *chip)
 262 {
 263         union acpi_object *obj;
 264         int rc;
 265
 266         obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
 267                                 &crb_acpi_start_guid,
 268                                 CRB_ACPI_START_REVISION_ID,
 269                                 CRB_ACPI_START_INDEX,
 270                                 NULL);
 271         if (!obj)
 272                 return -ENXIO;
 273         rc = obj->integer.value == 0 ? 0 : -ENXIO;
 274         ACPI_FREE(obj);
 275         return rc;
 276 }
 277
 278 #ifdef CONFIG_ARM64
 279 /*
 280  * This is a TPM Command Response Buffer start method that invokes a
 281  * Secure Monitor Call to requrest the firmware to execute or cancel
 282  * a TPM 2.0 command.
 283  */
 284 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
 285 {
 286         struct arm_smccc_res res;
 287
 288         arm_smccc_smc(func_id, 0, 0, 0, 0, 0, 0, 0, &res);
 289         if (res.a0 != 0) {
 290                 dev_err(dev,
 291                         FW_BUG "tpm_crb_smc_start() returns res.a0 = 0x%lx\n",
 292                         res.a0);
 293                 return -EIO;
 294         }
 295
 296         return 0;
 297 }
 298 #else
 299 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
 300 {
 301         dev_err(dev, FW_BUG "tpm_crb: incorrect start method\n");
 302         return -EINVAL;
 303 }
 304 #endif
 305
 306 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
 307 {
 308         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 309         int rc = 0;
 310
 311         /* Zero the cancel register so that the next command will not get
 312          * canceled.
 313          */
 314         iowrite32(0, &priv->regs_t->ctrl_cancel);
 315
 316         if (len > priv->cmd_size) {
 317                 dev_err(&chip->dev, "invalid command count value %zd %d\n",
 318                         len, priv->cmd_size);
 319                 return -E2BIG;
 320         }
 321
 322         memcpy_toio(priv->cmd, buf, len);
 323
 324         /* Make sure that cmd is populated before issuing start. */
 325         wmb();
 326
 327         /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
 328          * report only ACPI start but in practice seems to require both
 329          * CRB start, hence invoking CRB start method if hid == MSFT0101.
 330          */
 331         if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
 332             (priv->sm == ACPI_TPM2_MEMORY_MAPPED) ||
 333             (!strcmp(priv->hid, "MSFT0101")))
 334                 iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
 335
 336         if ((priv->sm == ACPI_TPM2_START_METHOD) ||
 337             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD))
 338                 rc = crb_do_acpi_start(chip);
 339
 340         if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
 341                 iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
 342                 rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
 343         }
 344
 345         return rc;
 346 }
 347
 348 static void crb_cancel(struct tpm_chip *chip)
 349 {
 350         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 351
 352         iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
 353
 354         if (((priv->sm == ACPI_TPM2_START_METHOD) ||
 355             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)) &&
 356              crb_do_acpi_start(chip))
 357                 dev_err(&chip->dev, "ACPI Start failed\n");
 358 }
 359
 360 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
 361 {
 362         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 363         u32 cancel = ioread32(&priv->regs_t->ctrl_cancel);
 364
 365         return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
 366 }
 367
 368 static const struct tpm_class_ops tpm_crb = {
 369         .flags = TPM_OPS_AUTO_STARTUP,
 370         .status = crb_status,
 371         .recv = crb_recv,
 372         .send = crb_send,
 373         .cancel = crb_cancel,
 374         .req_canceled = crb_req_canceled,
 375         .request_locality = crb_request_locality,
 376         .relinquish_locality = crb_relinquish_locality,
 377         .req_complete_mask = CRB_DRV_STS_COMPLETE,
 378         .req_complete_val = CRB_DRV_STS_COMPLETE,
 379 };
 380
 381 static int crb_check_resource(struct acpi_resource *ares, void *data)
 382 {
 383         struct resource *io_res = data;
 384         struct resource_win win;
 385         struct resource *res = &(win.res);
 386
 387         if (acpi_dev_resource_memory(ares, res) ||
 388             acpi_dev_resource_address_space(ares, &win)) {
 389                 *io_res = *res;
 390                 io_res->name = NULL;
 391         }
 392
 393         return 1;
 394 }
 395
 396 static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv,
 397                                  struct resource *io_res, u64 start, u32 size)
 398 {
 399         struct resource new_res = {
 400                 .start  = start,
 401                 .end    = start + size - 1,
 402                 .flags  = IORESOURCE_MEM,
 403         };
 404
 405         /* Detect a 64 bit address on a 32 bit system */
 406         if (start != new_res.start)
 407                 return (void __iomem *) ERR_PTR(-EINVAL);
 408
 409         if (!resource_contains(io_res, &new_res))
 410                 return devm_ioremap_resource(dev, &new_res);
 411
 412         return priv->iobase + (new_res.start - io_res->start);
 413 }
 414
 415 /*
 416  * Work around broken BIOSs that return inconsistent values from the ACPI
 417  * region vs the registers. Trust the ACPI region. Such broken systems
 418  * probably cannot send large TPM commands since the buffer will be truncated.
 419  */
 420 static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res,
 421                               u64 start, u64 size)
 422 {
 423         if (io_res->start > start || io_res->end < start)
 424                 return size;
 425
 426         if (start + size - 1 <= io_res->end)
 427                 return size;
 428
 429         dev_err(dev,
 430                 FW_BUG "ACPI region does not cover the entire command/response buffer. %pr vs %llx %llx\n",
 431                 io_res, start, size);
 432
 433         return io_res->end - start + 1;
 434 }
 435
 436 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
 437                       struct acpi_table_tpm2 *buf)
 438 {
 439         struct list_head resources;
 440         struct resource io_res;
 441         struct device *dev = &device->dev;
 442         u32 pa_high, pa_low;
 443         u64 cmd_pa;
 444         u32 cmd_size;
 445         u64 rsp_pa;
 446         u32 rsp_size;
 447         int ret;
 448
 449         INIT_LIST_HEAD(&resources);
 450         ret = acpi_dev_get_resources(device, &resources, crb_check_resource,
 451                                      &io_res);
 452         if (ret < 0)
 453                 return ret;
 454         acpi_dev_free_resource_list(&resources);
 455
 456         if (resource_type(&io_res) != IORESOURCE_MEM) {
 457                 dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
 458                 return -EINVAL;
 459         }
 460
 461         priv->iobase = devm_ioremap_resource(dev, &io_res);
 462         if (IS_ERR(priv->iobase))
 463                 return PTR_ERR(priv->iobase);
 464
 465         /* The ACPI IO region starts at the head area and continues to include
 466          * the control area, as one nice sane region except for some older
 467          * stuff that puts the control area outside the ACPI IO region.
 468          */
 469         if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
 470             (priv->sm == ACPI_TPM2_MEMORY_MAPPED)) {
 471                 if (buf->control_address == io_res.start +
 472                     sizeof(*priv->regs_h))
 473                         priv->regs_h = priv->iobase;
 474                 else
 475                         dev_warn(dev, FW_BUG "Bad ACPI memory layout");
 476         }
 477
 478         priv->regs_t = crb_map_res(dev, priv, &io_res, buf->control_address,
 479                                    sizeof(struct crb_regs_tail));
 480         if (IS_ERR(priv->regs_t))
 481                 return PTR_ERR(priv->regs_t);
 482
 483         /*
 484          * PTT HW bug w/a: wake up the device to access
 485          * possibly not retained registers.
 486          */
 487         ret = crb_cmd_ready(dev, priv);
 488         if (ret)
 489                 return ret;
 490
 491         pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high);
 492         pa_low  = ioread32(&priv->regs_t->ctrl_cmd_pa_low);
 493         cmd_pa = ((u64)pa_high << 32) | pa_low;
 494         cmd_size = crb_fixup_cmd_size(dev, &io_res, cmd_pa,
 495                                       ioread32(&priv->regs_t->ctrl_cmd_size));
 496
 497         dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
 498                 pa_high, pa_low, cmd_size);
 499
 500         priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size);
 501         if (IS_ERR(priv->cmd)) {
 502                 ret = PTR_ERR(priv->cmd);
 503                 goto out;
 504         }
 505
 506         memcpy_fromio(&rsp_pa, &priv->regs_t->ctrl_rsp_pa, 8);
 507         rsp_pa = le64_to_cpu(rsp_pa);
 508         rsp_size = crb_fixup_cmd_size(dev, &io_res, rsp_pa,
 509                                       ioread32(&priv->regs_t->ctrl_rsp_size));
 510
 511         if (cmd_pa != rsp_pa) {
 512                 priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size);
 513                 ret = PTR_ERR_OR_ZERO(priv->rsp);
 514                 goto out;
 515         }
 516
 517         /* According to the PTP specification, overlapping command and response
 518          * buffer sizes must be identical.
 519          */
 520         if (cmd_size != rsp_size) {
 521                 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
 522                 ret = -EINVAL;
 523                 goto out;
 524         }
 525
 526         priv->rsp = priv->cmd;
 527
 528 out:
 529         if (!ret)
 530                 priv->cmd_size = cmd_size;
 531
 532         crb_go_idle(dev, priv);
 533
 534         return ret;
 535 }
 536
 537 static int crb_acpi_add(struct acpi_device *device)
 538 {
 539         struct acpi_table_tpm2 *buf;
 540         struct crb_priv *priv;
 541         struct tpm_chip *chip;
 542         struct device *dev = &device->dev;
 543         struct tpm2_crb_smc *crb_smc;
 544         acpi_status status;
 545         u32 sm;
 546         int rc;
 547
 548         status = acpi_get_table(ACPI_SIG_TPM2, 1,
 549                                 (struct acpi_table_header **) &buf);
 550         if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
 551                 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
 552                 return -EINVAL;
 553         }
 554
 555         /* Should the FIFO driver handle this? */
 556         sm = buf->start_method;
 557         if (sm == ACPI_TPM2_MEMORY_MAPPED)
 558                 return -ENODEV;
 559
 560         priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
 561         if (!priv)
 562                 return -ENOMEM;
 563
 564         if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
 565                 if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) {
 566                         dev_err(dev,
 567                                 FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
 568                                 buf->header.length,
 569                                 ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
 570                         return -EINVAL;
 571                 }
 572                 crb_smc = ACPI_ADD_PTR(struct tpm2_crb_smc, buf, sizeof(*buf));
 573                 priv->smc_func_id = crb_smc->smc_func_id;
 574         }
 575
 576         priv->sm = sm;
 577         priv->hid = acpi_device_hid(device);
 578
 579         rc = crb_map_io(device, priv, buf);
 580         if (rc)
 581                 return rc;
 582
 583         chip = tpmm_chip_alloc(dev, &tpm_crb);
 584         if (IS_ERR(chip))
 585                 return PTR_ERR(chip);
 586
 587         dev_set_drvdata(&chip->dev, priv);
 588         chip->acpi_dev_handle = device->handle;
 589         chip->flags = TPM_CHIP_FLAG_TPM2;
 590
 591         rc  = crb_cmd_ready(dev, priv);
 592         if (rc)
 593                 return rc;
 594
 595         pm_runtime_get_noresume(dev);
 596         pm_runtime_set_active(dev);
 597         pm_runtime_enable(dev);
 598
 599         rc = tpm_chip_register(chip);
 600         if (rc) {
 601                 crb_go_idle(dev, priv);
 602                 pm_runtime_put_noidle(dev);
 603                 pm_runtime_disable(dev);
 604                 return rc;
 605         }
 606
 607         pm_runtime_put(dev);
 608
 609         return 0;
 610 }
 611
 612 static int crb_acpi_remove(struct acpi_device *device)
 613 {
 614         struct device *dev = &device->dev;
 615         struct tpm_chip *chip = dev_get_drvdata(dev);
 616
 617         tpm_chip_unregister(chip);
 618
 619         pm_runtime_disable(dev);
 620
 621         return 0;
 622 }
 623
 624 static int __maybe_unused crb_pm_runtime_suspend(struct device *dev)
 625 {
 626         struct tpm_chip *chip = dev_get_drvdata(dev);
 627         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 628
 629         return crb_go_idle(dev, priv);
 630 }
 631
 632 static int __maybe_unused crb_pm_runtime_resume(struct device *dev)
 633 {
 634         struct tpm_chip *chip = dev_get_drvdata(dev);
 635         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 636
 637         return crb_cmd_ready(dev, priv);
 638 }
 639
 640 static int __maybe_unused crb_pm_suspend(struct device *dev)
 641 {
 642         int ret;
 643
 644         ret = tpm_pm_suspend(dev);
 645         if (ret)
 646                 return ret;
 647
 648         return crb_pm_runtime_suspend(dev);
 649 }
 650
 651 static int __maybe_unused crb_pm_resume(struct device *dev)
 652 {
 653         int ret;
 654
 655         ret = crb_pm_runtime_resume(dev);
 656         if (ret)
 657                 return ret;
 658
 659         return tpm_pm_resume(dev);
 660 }
 661
 662 static const struct dev_pm_ops crb_pm = {
 663         SET_SYSTEM_SLEEP_PM_OPS(crb_pm_suspend, crb_pm_resume)
 664         SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend, crb_pm_runtime_resume, NULL)
 665 };
 666
 667 static const struct acpi_device_id crb_device_ids[] = {
 668         {"MSFT0101", 0},
 669         {"", 0},
 670 };
 671 MODULE_DEVICE_TABLE(acpi, crb_device_ids);
 672
 673 static struct acpi_driver crb_acpi_driver = {
 674         .name = "tpm_crb",
 675         .ids = crb_device_ids,
 676         .ops = {
 677                 .add = crb_acpi_add,
 678                 .remove = crb_acpi_remove,
 679         },
 680         .drv = {
 681                 .pm = &crb_pm,
 682         },
 683 };
 684
 685 module_acpi_driver(crb_acpi_driver);
 686 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
 687 MODULE_DESCRIPTION("TPM2 Driver");
 688 MODULE_VERSION("0.1");
 689 MODULE_LICENSE("GPL");