drivers/char/tpm/tpm_tis.c

   1 /*
   2  * Copyright (C) 2005, 2006 IBM Corporation
   3  * Copyright (C) 2014, 2015 Intel Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <leendert@watson.ibm.com>
   7  * Kylene Hall <kjhall@us.ibm.com>
   8  *
   9  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  10  *
  11  * Device driver for TCG/TCPA TPM (trusted platform module).
  12  * Specifications at www.trustedcomputinggroup.org
  13  *
  14  * This device driver implements the TPM interface as defined in
  15  * the TCG TPM Interface Spec version 1.2, revision 1.0.
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License as
  19  * published by the Free Software Foundation, version 2 of the
  20  * License.
  21  */
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/pnp.h>
  26 #include <linux/slab.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/wait.h>
  29 #include <linux/acpi.h>
  30 #include <linux/freezer.h>
  31 #include <linux/of.h>
  32 #include <linux/of_device.h>
  33 #include "tpm.h"
  34 #include "tpm_tis_core.h"
  35
  36 struct tpm_info {
  37         struct resource res;
  38         /* irq > 0 means: use irq $irq;
  39          * irq = 0 means: autoprobe for an irq;
  40          * irq = -1 means: no irq support
  41          */
  42         int irq;
  43 };
  44
  45 struct tpm_tis_tcg_phy {
  46         struct tpm_tis_data priv;
  47         void __iomem *iobase;
  48 };
  49
  50 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
  51 {
  52         return container_of(data, struct tpm_tis_tcg_phy, priv);
  53 }
  54
  55 static bool interrupts = true;
  56 module_param(interrupts, bool, 0444);
  57 MODULE_PARM_DESC(interrupts, "Enable interrupts");
  58
  59 static bool itpm;
  60 module_param(itpm, bool, 0444);
  61 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
  62
  63 static bool force;
  64 #ifdef CONFIG_X86
  65 module_param(force, bool, 0444);
  66 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
  67 #endif
  68
  69 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
  70 static int has_hid(struct acpi_device *dev, const char *hid)
  71 {
  72         struct acpi_hardware_id *id;
  73
  74         list_for_each_entry(id, &dev->pnp.ids, list)
  75                 if (!strcmp(hid, id->id))
  76                         return 1;
  77
  78         return 0;
  79 }
  80
  81 static inline int is_itpm(struct acpi_device *dev)
  82 {
  83         if (!dev)
  84                 return 0;
  85         return has_hid(dev, "INTC0102");
  86 }
  87 #else
  88 static inline int is_itpm(struct acpi_device *dev)
  89 {
  90         return 0;
  91 }
  92 #endif
  93
  94 #if defined(CONFIG_ACPI)
  95 #define DEVICE_IS_TPM2 1
  96
  97 static const struct acpi_device_id tpm_acpi_tbl[] = {
  98         {"MSFT0101", DEVICE_IS_TPM2},
  99         {},
 100 };
 101 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
 102
 103 static int check_acpi_tpm2(struct device *dev)
 104 {
 105         const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
 106         struct acpi_table_tpm2 *tbl;
 107         acpi_status st;
 108
 109         if (!aid || aid->driver_data != DEVICE_IS_TPM2)
 110                 return 0;
 111
 112         /* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
 113          * table is mandatory
 114          */
 115         st =
 116             acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
 117         if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
 118                 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
 119                 return -EINVAL;
 120         }
 121
 122         /* The tpm2_crb driver handles this device */
 123         if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
 124                 return -ENODEV;
 125
 126         return 0;
 127 }
 128 #else
 129 static int check_acpi_tpm2(struct device *dev)
 130 {
 131         return 0;
 132 }
 133 #endif
 134
 135 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 136                               u8 *result)
 137 {
 138         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 139
 140         while (len--)
 141                 *result++ = ioread8(phy->iobase + addr);
 142
 143         return 0;
 144 }
 145
 146 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 147                                const u8 *value)
 148 {
 149         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 150
 151         while (len--)
 152                 iowrite8(*value++, phy->iobase + addr);
 153
 154         return 0;
 155 }
 156
 157 static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
 158 {
 159         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 160
 161         *result = ioread16(phy->iobase + addr);
 162
 163         return 0;
 164 }
 165
 166 static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
 167 {
 168         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 169
 170         *result = ioread32(phy->iobase + addr);
 171
 172         return 0;
 173 }
 174
 175 static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
 176 {
 177         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 178
 179         iowrite32(value, phy->iobase + addr);
 180
 181         return 0;
 182 }
 183
 184 static const struct tpm_tis_phy_ops tpm_tcg = {
 185         .read_bytes = tpm_tcg_read_bytes,
 186         .write_bytes = tpm_tcg_write_bytes,
 187         .read16 = tpm_tcg_read16,
 188         .read32 = tpm_tcg_read32,
 189         .write32 = tpm_tcg_write32,
 190 };
 191
 192 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
 193 {
 194         struct tpm_tis_tcg_phy *phy;
 195         int irq = -1;
 196         int rc;
 197
 198         rc = check_acpi_tpm2(dev);
 199         if (rc)
 200                 return rc;
 201
 202         phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
 203         if (phy == NULL)
 204                 return -ENOMEM;
 205
 206         phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
 207         if (IS_ERR(phy->iobase))
 208                 return PTR_ERR(phy->iobase);
 209
 210         if (interrupts)
 211                 irq = tpm_info->irq;
 212
 213         if (itpm || is_itpm(ACPI_COMPANION(dev)))
 214                 phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
 215
 216         return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
 217                                  ACPI_HANDLE(dev));
 218 }
 219
 220 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
 221
 222 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
 223                             const struct pnp_device_id *pnp_id)
 224 {
 225         struct tpm_info tpm_info = {};
 226         struct resource *res;
 227
 228         res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
 229         if (!res)
 230                 return -ENODEV;
 231         tpm_info.res = *res;
 232
 233         if (pnp_irq_valid(pnp_dev, 0))
 234                 tpm_info.irq = pnp_irq(pnp_dev, 0);
 235         else
 236                 tpm_info.irq = -1;
 237
 238         return tpm_tis_init(&pnp_dev->dev, &tpm_info);
 239 }
 240
 241 static struct pnp_device_id tpm_pnp_tbl[] = {
 242         {"PNP0C31", 0},         /* TPM */
 243         {"ATM1200", 0},         /* Atmel */
 244         {"IFX0102", 0},         /* Infineon */
 245         {"BCM0101", 0},         /* Broadcom */
 246         {"BCM0102", 0},         /* Broadcom */
 247         {"NSC1200", 0},         /* National */
 248         {"ICO0102", 0},         /* Intel */
 249         /* Add new here */
 250         {"", 0},                /* User Specified */
 251         {"", 0}                 /* Terminator */
 252 };
 253 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
 254
 255 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
 256 {
 257         struct tpm_chip *chip = pnp_get_drvdata(dev);
 258
 259         tpm_chip_unregister(chip);
 260         tpm_tis_remove(chip);
 261 }
 262
 263 static struct pnp_driver tis_pnp_driver = {
 264         .name = "tpm_tis",
 265         .id_table = tpm_pnp_tbl,
 266         .probe = tpm_tis_pnp_init,
 267         .remove = tpm_tis_pnp_remove,
 268         .driver = {
 269                 .pm = &tpm_tis_pm,
 270         },
 271 };
 272
 273 #define TIS_HID_USR_IDX sizeof(tpm_pnp_tbl)/sizeof(struct pnp_device_id) -2
 274 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
 275                     sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
 276 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
 277
 278 static struct platform_device *force_pdev;
 279
 280 static int tpm_tis_plat_probe(struct platform_device *pdev)
 281 {
 282         struct tpm_info tpm_info = {};
 283         struct resource *res;
 284
 285         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 286         if (res == NULL) {
 287                 dev_err(&pdev->dev, "no memory resource defined\n");
 288                 return -ENODEV;
 289         }
 290         tpm_info.res = *res;
 291
 292         tpm_info.irq = platform_get_irq(pdev, 0);
 293         if (tpm_info.irq <= 0) {
 294                 if (pdev != force_pdev)
 295                         tpm_info.irq = -1;
 296                 else
 297                         /* When forcing auto probe the IRQ */
 298                         tpm_info.irq = 0;
 299         }
 300
 301         return tpm_tis_init(&pdev->dev, &tpm_info);
 302 }
 303
 304 static int tpm_tis_plat_remove(struct platform_device *pdev)
 305 {
 306         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 307
 308         tpm_chip_unregister(chip);
 309         tpm_tis_remove(chip);
 310
 311         return 0;
 312 }
 313
 314 #ifdef CONFIG_OF
 315 static const struct of_device_id tis_of_platform_match[] = {
 316         {.compatible = "tcg,tpm-tis-mmio"},
 317         {},
 318 };
 319 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
 320 #endif
 321
 322 static struct platform_driver tis_drv = {
 323         .probe = tpm_tis_plat_probe,
 324         .remove = tpm_tis_plat_remove,
 325         .driver = {
 326                 .name           = "tpm_tis",
 327                 .pm             = &tpm_tis_pm,
 328                 .of_match_table = of_match_ptr(tis_of_platform_match),
 329                 .acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
 330         },
 331 };
 332
 333 static int tpm_tis_force_device(void)
 334 {
 335         struct platform_device *pdev;
 336         static const struct resource x86_resources[] = {
 337                 {
 338                         .start = 0xFED40000,
 339                         .end = 0xFED40000 + TIS_MEM_LEN - 1,
 340                         .flags = IORESOURCE_MEM,
 341                 },
 342         };
 343
 344         if (!force)
 345                 return 0;
 346
 347         /* The driver core will match the name tpm_tis of the device to
 348          * the tpm_tis platform driver and complete the setup via
 349          * tpm_tis_plat_probe
 350          */
 351         pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
 352                                                ARRAY_SIZE(x86_resources));
 353         if (IS_ERR(pdev))
 354                 return PTR_ERR(pdev);
 355         force_pdev = pdev;
 356
 357         return 0;
 358 }
 359
 360 static int __init init_tis(void)
 361 {
 362         int rc;
 363
 364         rc = tpm_tis_force_device();
 365         if (rc)
 366                 goto err_force;
 367
 368         rc = platform_driver_register(&tis_drv);
 369         if (rc)
 370                 goto err_platform;
 371
 372
 373         if (IS_ENABLED(CONFIG_PNP)) {
 374                 rc = pnp_register_driver(&tis_pnp_driver);
 375                 if (rc)
 376                         goto err_pnp;
 377         }
 378
 379         return 0;
 380
 381 err_pnp:
 382         platform_driver_unregister(&tis_drv);
 383 err_platform:
 384         if (force_pdev)
 385                 platform_device_unregister(force_pdev);
 386 err_force:
 387         return rc;
 388 }
 389
 390 static void __exit cleanup_tis(void)
 391 {
 392         pnp_unregister_driver(&tis_pnp_driver);
 393         platform_driver_unregister(&tis_drv);
 394
 395         if (force_pdev)
 396                 platform_device_unregister(force_pdev);
 397 }
 398
 399 module_init(init_tis);
 400 module_exit(cleanup_tis);
 401 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 402 MODULE_DESCRIPTION("TPM Driver");
 403 MODULE_VERSION("2.0");
 404 MODULE_LICENSE("GPL");