drivers/char/tpm/tpm_tis.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2005, 2006 IBM Corporation
   4  * Copyright (C) 2014, 2015 Intel Corporation
   5  *
   6  * Authors:
   7  * Leendert van Doorn <leendert@watson.ibm.com>
   8  * Kylene Hall <kjhall@us.ibm.com>
   9  *
  10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  11  *
  12  * Device driver for TCG/TCPA TPM (trusted platform module).
  13  * Specifications at www.trustedcomputinggroup.org
  14  *
  15  * This device driver implements the TPM interface as defined in
  16  * the TCG TPM Interface Spec version 1.2, revision 1.0.
  17  */
  18 #include <linux/init.h>
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/pnp.h>
  22 #include <linux/slab.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/wait.h>
  25 #include <linux/acpi.h>
  26 #include <linux/freezer.h>
  27 #include <linux/of.h>
  28 #include <linux/of_device.h>
  29 #include <linux/kernel.h>
  30 #include "tpm.h"
  31 #include "tpm_tis_core.h"
  32
  33 struct tpm_info {
  34         struct resource res;
  35         /* irq > 0 means: use irq $irq;
  36          * irq = 0 means: autoprobe for an irq;
  37          * irq = -1 means: no irq support
  38          */
  39         int irq;
  40 };
  41
  42 struct tpm_tis_tcg_phy {
  43         struct tpm_tis_data priv;
  44         void __iomem *iobase;
  45 };
  46
  47 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
  48 {
  49         return container_of(data, struct tpm_tis_tcg_phy, priv);
  50 }
  51
  52 static bool interrupts = true;
  53 module_param(interrupts, bool, 0444);
  54 MODULE_PARM_DESC(interrupts, "Enable interrupts");
  55
  56 static bool itpm;
  57 module_param(itpm, bool, 0444);
  58 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
  59
  60 static bool force;
  61 #ifdef CONFIG_X86
  62 module_param(force, bool, 0444);
  63 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
  64 #endif
  65
  66 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
  67 static int has_hid(struct acpi_device *dev, const char *hid)
  68 {
  69         struct acpi_hardware_id *id;
  70
  71         list_for_each_entry(id, &dev->pnp.ids, list)
  72                 if (!strcmp(hid, id->id))
  73                         return 1;
  74
  75         return 0;
  76 }
  77
  78 static inline int is_itpm(struct acpi_device *dev)
  79 {
  80         if (!dev)
  81                 return 0;
  82         return has_hid(dev, "INTC0102");
  83 }
  84 #else
  85 static inline int is_itpm(struct acpi_device *dev)
  86 {
  87         return 0;
  88 }
  89 #endif
  90
  91 #if defined(CONFIG_ACPI)
  92 #define DEVICE_IS_TPM2 1
  93
  94 static const struct acpi_device_id tpm_acpi_tbl[] = {
  95         {"MSFT0101", DEVICE_IS_TPM2},
  96         {},
  97 };
  98 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
  99
 100 static int check_acpi_tpm2(struct device *dev)
 101 {
 102         const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
 103         struct acpi_table_tpm2 *tbl;
 104         acpi_status st;
 105
 106         if (!aid || aid->driver_data != DEVICE_IS_TPM2)
 107                 return 0;
 108
 109         /* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
 110          * table is mandatory
 111          */
 112         st =
 113             acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
 114         if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
 115                 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
 116                 return -EINVAL;
 117         }
 118
 119         /* The tpm2_crb driver handles this device */
 120         if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
 121                 return -ENODEV;
 122
 123         return 0;
 124 }
 125 #else
 126 static int check_acpi_tpm2(struct device *dev)
 127 {
 128         return 0;
 129 }
 130 #endif
 131
 132 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 133                               u8 *result)
 134 {
 135         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 136
 137         while (len--)
 138                 *result++ = ioread8(phy->iobase + addr);
 139
 140         return 0;
 141 }
 142
 143 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 144                                const u8 *value)
 145 {
 146         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 147
 148         while (len--)
 149                 iowrite8(*value++, phy->iobase + addr);
 150
 151         return 0;
 152 }
 153
 154 static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
 155 {
 156         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 157
 158         *result = ioread16(phy->iobase + addr);
 159
 160         return 0;
 161 }
 162
 163 static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
 164 {
 165         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 166
 167         *result = ioread32(phy->iobase + addr);
 168
 169         return 0;
 170 }
 171
 172 static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
 173 {
 174         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 175
 176         iowrite32(value, phy->iobase + addr);
 177
 178         return 0;
 179 }
 180
 181 static const struct tpm_tis_phy_ops tpm_tcg = {
 182         .read_bytes = tpm_tcg_read_bytes,
 183         .write_bytes = tpm_tcg_write_bytes,
 184         .read16 = tpm_tcg_read16,
 185         .read32 = tpm_tcg_read32,
 186         .write32 = tpm_tcg_write32,
 187 };
 188
 189 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
 190 {
 191         struct tpm_tis_tcg_phy *phy;
 192         int irq = -1;
 193         int rc;
 194
 195         rc = check_acpi_tpm2(dev);
 196         if (rc)
 197                 return rc;
 198
 199         phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
 200         if (phy == NULL)
 201                 return -ENOMEM;
 202
 203         phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
 204         if (IS_ERR(phy->iobase))
 205                 return PTR_ERR(phy->iobase);
 206
 207         if (interrupts)
 208                 irq = tpm_info->irq;
 209
 210         if (itpm || is_itpm(ACPI_COMPANION(dev)))
 211                 phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
 212
 213         return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
 214                                  ACPI_HANDLE(dev));
 215 }
 216
 217 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
 218
 219 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
 220                             const struct pnp_device_id *pnp_id)
 221 {
 222         struct tpm_info tpm_info = {};
 223         struct resource *res;
 224
 225         res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
 226         if (!res)
 227                 return -ENODEV;
 228         tpm_info.res = *res;
 229
 230         if (pnp_irq_valid(pnp_dev, 0))
 231                 tpm_info.irq = pnp_irq(pnp_dev, 0);
 232         else
 233                 tpm_info.irq = -1;
 234
 235         return tpm_tis_init(&pnp_dev->dev, &tpm_info);
 236 }
 237
 238 static struct pnp_device_id tpm_pnp_tbl[] = {
 239         {"PNP0C31", 0},         /* TPM */
 240         {"ATM1200", 0},         /* Atmel */
 241         {"BCM0101", 0},         /* Broadcom */
 242         {"BCM0102", 0},         /* Broadcom */
 243         {"NSC1200", 0},         /* National */
 244         {"ICO0102", 0},         /* Intel */
 245         /* Add new here */
 246         {"", 0},                /* User Specified */
 247         {"", 0}                 /* Terminator */
 248 };
 249 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
 250
 251 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
 252 {
 253         struct tpm_chip *chip = pnp_get_drvdata(dev);
 254
 255         tpm_chip_unregister(chip);
 256         tpm_tis_remove(chip);
 257 }
 258
 259 static struct pnp_driver tis_pnp_driver = {
 260         .name = "tpm_tis",
 261         .id_table = tpm_pnp_tbl,
 262         .probe = tpm_tis_pnp_init,
 263         .remove = tpm_tis_pnp_remove,
 264         .driver = {
 265                 .pm = &tpm_tis_pm,
 266         },
 267 };
 268
 269 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
 270 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
 271                     sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
 272 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
 273
 274 static struct platform_device *force_pdev;
 275
 276 static int tpm_tis_plat_probe(struct platform_device *pdev)
 277 {
 278         struct tpm_info tpm_info = {};
 279         struct resource *res;
 280
 281         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 282         if (res == NULL) {
 283                 dev_err(&pdev->dev, "no memory resource defined\n");
 284                 return -ENODEV;
 285         }
 286         tpm_info.res = *res;
 287
 288         tpm_info.irq = platform_get_irq_optional(pdev, 0);
 289         if (tpm_info.irq <= 0) {
 290                 if (pdev != force_pdev)
 291                         tpm_info.irq = -1;
 292                 else
 293                         /* When forcing auto probe the IRQ */
 294                         tpm_info.irq = 0;
 295         }
 296
 297         return tpm_tis_init(&pdev->dev, &tpm_info);
 298 }
 299
 300 static int tpm_tis_plat_remove(struct platform_device *pdev)
 301 {
 302         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 303
 304         tpm_chip_unregister(chip);
 305         tpm_tis_remove(chip);
 306
 307         return 0;
 308 }
 309
 310 #ifdef CONFIG_OF
 311 static const struct of_device_id tis_of_platform_match[] = {
 312         {.compatible = "tcg,tpm-tis-mmio"},
 313         {},
 314 };
 315 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
 316 #endif
 317
 318 static struct platform_driver tis_drv = {
 319         .probe = tpm_tis_plat_probe,
 320         .remove = tpm_tis_plat_remove,
 321         .driver = {
 322                 .name           = "tpm_tis",
 323                 .pm             = &tpm_tis_pm,
 324                 .of_match_table = of_match_ptr(tis_of_platform_match),
 325                 .acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
 326         },
 327 };
 328
 329 static int tpm_tis_force_device(void)
 330 {
 331         struct platform_device *pdev;
 332         static const struct resource x86_resources[] = {
 333                 {
 334                         .start = 0xFED40000,
 335                         .end = 0xFED40000 + TIS_MEM_LEN - 1,
 336                         .flags = IORESOURCE_MEM,
 337                 },
 338         };
 339
 340         if (!force)
 341                 return 0;
 342
 343         /* The driver core will match the name tpm_tis of the device to
 344          * the tpm_tis platform driver and complete the setup via
 345          * tpm_tis_plat_probe
 346          */
 347         pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
 348                                                ARRAY_SIZE(x86_resources));
 349         if (IS_ERR(pdev))
 350                 return PTR_ERR(pdev);
 351         force_pdev = pdev;
 352
 353         return 0;
 354 }
 355
 356 static int __init init_tis(void)
 357 {
 358         int rc;
 359
 360         rc = tpm_tis_force_device();
 361         if (rc)
 362                 goto err_force;
 363
 364         rc = platform_driver_register(&tis_drv);
 365         if (rc)
 366                 goto err_platform;
 367
 368
 369         if (IS_ENABLED(CONFIG_PNP)) {
 370                 rc = pnp_register_driver(&tis_pnp_driver);
 371                 if (rc)
 372                         goto err_pnp;
 373         }
 374
 375         return 0;
 376
 377 err_pnp:
 378         platform_driver_unregister(&tis_drv);
 379 err_platform:
 380         if (force_pdev)
 381                 platform_device_unregister(force_pdev);
 382 err_force:
 383         return rc;
 384 }
 385
 386 static void __exit cleanup_tis(void)
 387 {
 388         pnp_unregister_driver(&tis_pnp_driver);
 389         platform_driver_unregister(&tis_drv);
 390
 391         if (force_pdev)
 392                 platform_device_unregister(force_pdev);
 393 }
 394
 395 module_init(init_tis);
 396 module_exit(cleanup_tis);
 397 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 398 MODULE_DESCRIPTION("TPM Driver");
 399 MODULE_VERSION("2.0");
 400 MODULE_LICENSE("GPL");