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