linux/drivers/char/tpm/tpm_nsc.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2004 IBM Corporation
   4 *
   5 * Authors:
   6 * Leendert van Doorn <leendert@watson.ibm.com>
   7 * Dave Safford <safford@watson.ibm.com>
   8 * Reiner Sailer <sailer@watson.ibm.com>
   9 * Kylene Hall <kjhall@us.ibm.com>
  10 *
  11 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12 *
  13 * Device driver for TCG/TCPA TPM (trusted platform module).
  14 * Specifications at www.trustedcomputinggroup.org       
  15 */
  16
  17#include <linux/platform_device.h>
  18#include <linux/slab.h>
  19#include "tpm.h"
  20
  21/* National definitions */
  22enum tpm_nsc_addr{
  23        TPM_NSC_IRQ = 0x07,
  24        TPM_NSC_BASE0_HI = 0x60,
  25        TPM_NSC_BASE0_LO = 0x61,
  26        TPM_NSC_BASE1_HI = 0x62,
  27        TPM_NSC_BASE1_LO = 0x63
  28};
  29
  30enum tpm_nsc_index {
  31        NSC_LDN_INDEX = 0x07,
  32        NSC_SID_INDEX = 0x20,
  33        NSC_LDC_INDEX = 0x30,
  34        NSC_DIO_INDEX = 0x60,
  35        NSC_CIO_INDEX = 0x62,
  36        NSC_IRQ_INDEX = 0x70,
  37        NSC_ITS_INDEX = 0x71
  38};
  39
  40enum tpm_nsc_status_loc {
  41        NSC_STATUS = 0x01,
  42        NSC_COMMAND = 0x01,
  43        NSC_DATA = 0x00
  44};
  45
  46/* status bits */
  47enum tpm_nsc_status {
  48        NSC_STATUS_OBF = 0x01,  /* output buffer full */
  49        NSC_STATUS_IBF = 0x02,  /* input buffer full */
  50        NSC_STATUS_F0 = 0x04,   /* F0 */
  51        NSC_STATUS_A2 = 0x08,   /* A2 */
  52        NSC_STATUS_RDY = 0x10,  /* ready to receive command */
  53        NSC_STATUS_IBR = 0x20   /* ready to receive data */
  54};
  55
  56/* command bits */
  57enum tpm_nsc_cmd_mode {
  58        NSC_COMMAND_NORMAL = 0x01,      /* normal mode */
  59        NSC_COMMAND_EOC = 0x03,
  60        NSC_COMMAND_CANCEL = 0x22
  61};
  62
  63struct tpm_nsc_priv {
  64        unsigned long base;
  65};
  66
  67/*
  68 * Wait for a certain status to appear
  69 */
  70static int wait_for_stat(struct tpm_chip *chip, u8 mask, u8 val, u8 * data)
  71{
  72        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
  73        unsigned long stop;
  74
  75        /* status immediately available check */
  76        *data = inb(priv->base + NSC_STATUS);
  77        if ((*data & mask) == val)
  78                return 0;
  79
  80        /* wait for status */
  81        stop = jiffies + 10 * HZ;
  82        do {
  83                msleep(TPM_TIMEOUT);
  84                *data = inb(priv->base + 1);
  85                if ((*data & mask) == val)
  86                        return 0;
  87        }
  88        while (time_before(jiffies, stop));
  89
  90        return -EBUSY;
  91}
  92
  93static int nsc_wait_for_ready(struct tpm_chip *chip)
  94{
  95        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
  96        int status;
  97        unsigned long stop;
  98
  99        /* status immediately available check */
 100        status = inb(priv->base + NSC_STATUS);
 101        if (status & NSC_STATUS_OBF)
 102                status = inb(priv->base + NSC_DATA);
 103        if (status & NSC_STATUS_RDY)
 104                return 0;
 105
 106        /* wait for status */
 107        stop = jiffies + 100;
 108        do {
 109                msleep(TPM_TIMEOUT);
 110                status = inb(priv->base + NSC_STATUS);
 111                if (status & NSC_STATUS_OBF)
 112                        status = inb(priv->base + NSC_DATA);
 113                if (status & NSC_STATUS_RDY)
 114                        return 0;
 115        }
 116        while (time_before(jiffies, stop));
 117
 118        dev_info(&chip->dev, "wait for ready failed\n");
 119        return -EBUSY;
 120}
 121
 122
 123static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
 124{
 125        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
 126        u8 *buffer = buf;
 127        u8 data, *p;
 128        u32 size;
 129        __be32 *native_size;
 130
 131        if (count < 6)
 132                return -EIO;
 133
 134        if (wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0) {
 135                dev_err(&chip->dev, "F0 timeout\n");
 136                return -EIO;
 137        }
 138
 139        data = inb(priv->base + NSC_DATA);
 140        if (data != NSC_COMMAND_NORMAL) {
 141                dev_err(&chip->dev, "not in normal mode (0x%x)\n",
 142                        data);
 143                return -EIO;
 144        }
 145
 146        /* read the whole packet */
 147        for (p = buffer; p < &buffer[count]; p++) {
 148                if (wait_for_stat
 149                    (chip, NSC_STATUS_OBF, NSC_STATUS_OBF, &data) < 0) {
 150                        dev_err(&chip->dev,
 151                                "OBF timeout (while reading data)\n");
 152                        return -EIO;
 153                }
 154                if (data & NSC_STATUS_F0)
 155                        break;
 156                *p = inb(priv->base + NSC_DATA);
 157        }
 158
 159        if ((data & NSC_STATUS_F0) == 0 &&
 160        (wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0)) {
 161                dev_err(&chip->dev, "F0 not set\n");
 162                return -EIO;
 163        }
 164
 165        data = inb(priv->base + NSC_DATA);
 166        if (data != NSC_COMMAND_EOC) {
 167                dev_err(&chip->dev,
 168                        "expected end of command(0x%x)\n", data);
 169                return -EIO;
 170        }
 171
 172        native_size = (__force __be32 *) (buf + 2);
 173        size = be32_to_cpu(*native_size);
 174
 175        if (count < size)
 176                return -EIO;
 177
 178        return size;
 179}
 180
 181static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
 182{
 183        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
 184        u8 data;
 185        int i;
 186
 187        /*
 188         * If we hit the chip with back to back commands it locks up
 189         * and never set IBF. Hitting it with this "hammer" seems to
 190         * fix it. Not sure why this is needed, we followed the flow
 191         * chart in the manual to the letter.
 192         */
 193        outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
 194
 195        if (nsc_wait_for_ready(chip) != 0)
 196                return -EIO;
 197
 198        if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
 199                dev_err(&chip->dev, "IBF timeout\n");
 200                return -EIO;
 201        }
 202
 203        outb(NSC_COMMAND_NORMAL, priv->base + NSC_COMMAND);
 204        if (wait_for_stat(chip, NSC_STATUS_IBR, NSC_STATUS_IBR, &data) < 0) {
 205                dev_err(&chip->dev, "IBR timeout\n");
 206                return -EIO;
 207        }
 208
 209        for (i = 0; i < count; i++) {
 210                if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
 211                        dev_err(&chip->dev,
 212                                "IBF timeout (while writing data)\n");
 213                        return -EIO;
 214                }
 215                outb(buf[i], priv->base + NSC_DATA);
 216        }
 217
 218        if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
 219                dev_err(&chip->dev, "IBF timeout\n");
 220                return -EIO;
 221        }
 222        outb(NSC_COMMAND_EOC, priv->base + NSC_COMMAND);
 223
 224        return 0;
 225}
 226
 227static void tpm_nsc_cancel(struct tpm_chip *chip)
 228{
 229        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
 230
 231        outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
 232}
 233
 234static u8 tpm_nsc_status(struct tpm_chip *chip)
 235{
 236        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
 237
 238        return inb(priv->base + NSC_STATUS);
 239}
 240
 241static bool tpm_nsc_req_canceled(struct tpm_chip *chip, u8 status)
 242{
 243        return (status == NSC_STATUS_RDY);
 244}
 245
 246static const struct tpm_class_ops tpm_nsc = {
 247        .recv = tpm_nsc_recv,
 248        .send = tpm_nsc_send,
 249        .cancel = tpm_nsc_cancel,
 250        .status = tpm_nsc_status,
 251        .req_complete_mask = NSC_STATUS_OBF,
 252        .req_complete_val = NSC_STATUS_OBF,
 253        .req_canceled = tpm_nsc_req_canceled,
 254};
 255
 256static struct platform_device *pdev = NULL;
 257
 258static void tpm_nsc_remove(struct device *dev)
 259{
 260        struct tpm_chip *chip = dev_get_drvdata(dev);
 261        struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
 262
 263        tpm_chip_unregister(chip);
 264        release_region(priv->base, 2);
 265}
 266
 267static SIMPLE_DEV_PM_OPS(tpm_nsc_pm, tpm_pm_suspend, tpm_pm_resume);
 268
 269static struct platform_driver nsc_drv = {
 270        .driver          = {
 271                .name    = "tpm_nsc",
 272                .pm      = &tpm_nsc_pm,
 273        },
 274};
 275
 276static inline int tpm_read_index(int base, int index)
 277{
 278        outb(index, base);
 279        return inb(base+1) & 0xFF;
 280}
 281
 282static inline void tpm_write_index(int base, int index, int value)
 283{
 284        outb(index, base);
 285        outb(value & 0xFF, base+1);
 286}
 287
 288static int __init init_nsc(void)
 289{
 290        int rc = 0;
 291        int lo, hi, err;
 292        int nscAddrBase = TPM_ADDR;
 293        struct tpm_chip *chip;
 294        unsigned long base;
 295        struct tpm_nsc_priv *priv;
 296
 297        /* verify that it is a National part (SID) */
 298        if (tpm_read_index(TPM_ADDR, NSC_SID_INDEX) != 0xEF) {
 299                nscAddrBase = (tpm_read_index(TPM_SUPERIO_ADDR, 0x2C)<<8)|
 300                        (tpm_read_index(TPM_SUPERIO_ADDR, 0x2B)&0xFE);
 301                if (tpm_read_index(nscAddrBase, NSC_SID_INDEX) != 0xF6)
 302                        return -ENODEV;
 303        }
 304
 305        err = platform_driver_register(&nsc_drv);
 306        if (err)
 307                return err;
 308
 309        hi = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_HI);
 310        lo = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_LO);
 311        base = (hi<<8) | lo;
 312
 313        /* enable the DPM module */
 314        tpm_write_index(nscAddrBase, NSC_LDC_INDEX, 0x01);
 315
 316        pdev = platform_device_alloc("tpm_nscl0", -1);
 317        if (!pdev) {
 318                rc = -ENOMEM;
 319                goto err_unreg_drv;
 320        }
 321
 322        pdev->num_resources = 0;
 323        pdev->dev.driver = &nsc_drv.driver;
 324        pdev->dev.release = tpm_nsc_remove;
 325
 326        if ((rc = platform_device_add(pdev)) < 0)
 327                goto err_put_dev;
 328
 329        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 330        if (!priv) {
 331                rc = -ENOMEM;
 332                goto err_del_dev;
 333        }
 334
 335        priv->base = base;
 336
 337        if (request_region(base, 2, "tpm_nsc0") == NULL ) {
 338                rc = -EBUSY;
 339                goto err_del_dev;
 340        }
 341
 342        chip = tpmm_chip_alloc(&pdev->dev, &tpm_nsc);
 343        if (IS_ERR(chip)) {
 344                rc = -ENODEV;
 345                goto err_rel_reg;
 346        }
 347
 348        dev_set_drvdata(&chip->dev, priv);
 349
 350        rc = tpm_chip_register(chip);
 351        if (rc)
 352                goto err_rel_reg;
 353
 354        dev_dbg(&pdev->dev, "NSC TPM detected\n");
 355        dev_dbg(&pdev->dev,
 356                "NSC LDN 0x%x, SID 0x%x, SRID 0x%x\n",
 357                tpm_read_index(nscAddrBase,0x07), tpm_read_index(nscAddrBase,0x20),
 358                tpm_read_index(nscAddrBase,0x27));
 359        dev_dbg(&pdev->dev,
 360                "NSC SIOCF1 0x%x SIOCF5 0x%x SIOCF6 0x%x SIOCF8 0x%x\n",
 361                tpm_read_index(nscAddrBase,0x21), tpm_read_index(nscAddrBase,0x25),
 362                tpm_read_index(nscAddrBase,0x26), tpm_read_index(nscAddrBase,0x28));
 363        dev_dbg(&pdev->dev, "NSC IO Base0 0x%x\n",
 364                (tpm_read_index(nscAddrBase,0x60) << 8) | tpm_read_index(nscAddrBase,0x61));
 365        dev_dbg(&pdev->dev, "NSC IO Base1 0x%x\n",
 366                (tpm_read_index(nscAddrBase,0x62) << 8) | tpm_read_index(nscAddrBase,0x63));
 367        dev_dbg(&pdev->dev, "NSC Interrupt number and wakeup 0x%x\n",
 368                tpm_read_index(nscAddrBase,0x70));
 369        dev_dbg(&pdev->dev, "NSC IRQ type select 0x%x\n",
 370                tpm_read_index(nscAddrBase,0x71));
 371        dev_dbg(&pdev->dev,
 372                "NSC DMA channel select0 0x%x, select1 0x%x\n",
 373                tpm_read_index(nscAddrBase,0x74), tpm_read_index(nscAddrBase,0x75));
 374        dev_dbg(&pdev->dev,
 375                "NSC Config "
 376                "0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n",
 377                tpm_read_index(nscAddrBase,0xF0), tpm_read_index(nscAddrBase,0xF1),
 378                tpm_read_index(nscAddrBase,0xF2), tpm_read_index(nscAddrBase,0xF3),
 379                tpm_read_index(nscAddrBase,0xF4), tpm_read_index(nscAddrBase,0xF5),
 380                tpm_read_index(nscAddrBase,0xF6), tpm_read_index(nscAddrBase,0xF7),
 381                tpm_read_index(nscAddrBase,0xF8), tpm_read_index(nscAddrBase,0xF9));
 382
 383        dev_info(&pdev->dev,
 384                 "NSC TPM revision %d\n",
 385                 tpm_read_index(nscAddrBase, 0x27) & 0x1F);
 386
 387        return 0;
 388
 389err_rel_reg:
 390        release_region(base, 2);
 391err_del_dev:
 392        platform_device_del(pdev);
 393err_put_dev:
 394        platform_device_put(pdev);
 395err_unreg_drv:
 396        platform_driver_unregister(&nsc_drv);
 397        return rc;
 398}
 399
 400static void __exit cleanup_nsc(void)
 401{
 402        if (pdev) {
 403                tpm_nsc_remove(&pdev->dev);
 404                platform_device_unregister(pdev);
 405        }
 406
 407        platform_driver_unregister(&nsc_drv);
 408}
 409
 410module_init(init_nsc);
 411module_exit(cleanup_nsc);
 412
 413MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 414MODULE_DESCRIPTION("TPM Driver");
 415MODULE_VERSION("2.0");
 416MODULE_LICENSE("GPL");
 417