src/drivers/i2c/tpm/tis.c

   1 /*
   2  * Copyright (C) 2011 Infineon Technologies
   3  * Copyright 2013 Google Inc.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but without any warranty; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc.
  21  */
  22
  23 #include <stdint.h>
  24 #include <string.h>
  25 #include <assert.h>
  26 #include <delay.h>
  27 #include <device/i2c.h>
  28 #include <endian.h>
  29 #include <tpm.h>
  30 #include "tpm.h"
  31 #include <timer.h>
  32
  33 #include <console/console.h>
  34
  35 /* global structure for tpm chip data */
  36 struct tpm_chip g_chip;
  37
  38 #define TPM_CMD_COUNT_BYTE 2
  39 #define TPM_CMD_ORDINAL_BYTE 6
  40 #define TPM_VALID_STATUS (1 << 7)
  41
  42 int tis_open(void)
  43 {
  44         int rc;
  45
  46         if (g_chip.is_open) {
  47                 printk(BIOS_DEBUG, "tis_open() called twice.\n");
  48                 return -1;
  49         }
  50
  51         rc = tpm_vendor_init(CONFIG_DRIVER_TPM_I2C_BUS,
  52                                 CONFIG_DRIVER_TPM_I2C_ADDR);
  53
  54         if (rc < 0)
  55                 g_chip.is_open = 0;
  56
  57         if (rc) {
  58                 return -1;
  59         }
  60
  61         return 0;
  62 }
  63
  64 int tis_close(void)
  65 {
  66         if (g_chip.is_open) {
  67                 tpm_vendor_cleanup(&g_chip);
  68                 g_chip.is_open = 0;
  69         }
  70
  71         return 0;
  72 }
  73
  74 int tis_init(void)
  75 {
  76         int bus = CONFIG_DRIVER_TPM_I2C_BUS;
  77         int chip = CONFIG_DRIVER_TPM_I2C_ADDR;
  78         struct stopwatch sw;
  79         uint8_t buf = 0;
  80         int ret;
  81         long sw_run_duration = 750;
  82
  83         /*
  84          * Probe TPM. Check if the TPM_ACCESS register's ValidSts bit is set(1)
  85          * If the bit remains clear(0) then claim that init has failed.
  86          */
  87         stopwatch_init_msecs_expire(&sw, sw_run_duration);
  88         do {
  89                 ret = i2c_readb(bus, chip, 0, &buf);
  90                 if (!ret && (buf & TPM_VALID_STATUS)) {
  91                         sw_run_duration = stopwatch_duration_msecs(&sw);
  92                         break;
  93                 }
  94         } while (!stopwatch_expired(&sw));
  95
  96         printk(BIOS_INFO,
  97                "%s: ValidSts bit %s(%d) in TPM_ACCESS register after %ld ms\n",
  98                __func__, (buf & TPM_VALID_STATUS) ? "set" : "clear",
  99                (buf & TPM_VALID_STATUS) >> 7, sw_run_duration);
 100
 101         /*
 102          * Claim failure if the ValidSts (bit 7) is clear.
 103          */
 104         if (!(buf & TPM_VALID_STATUS))
 105                 return -1;
 106
 107         return 0;
 108 }
 109
 110 static ssize_t tpm_transmit(const uint8_t *buf, size_t bufsiz)
 111 {
 112         int rc;
 113         uint32_t count, ordinal;
 114
 115         struct tpm_chip *chip = &g_chip;
 116
 117         memcpy(&count, buf + TPM_CMD_COUNT_BYTE, sizeof(count));
 118         count = be32_to_cpu(count);
 119         memcpy(&ordinal, buf + TPM_CMD_ORDINAL_BYTE, sizeof(ordinal));
 120         ordinal = be32_to_cpu(ordinal);
 121
 122         if (count == 0) {
 123                 printk(BIOS_DEBUG, "tpm_transmit: no data\n");
 124                 return -1;
 125         }
 126         if (count > bufsiz) {
 127                 printk(BIOS_DEBUG, "tpm_transmit: invalid count value %x %zx\n",
 128                         count, bufsiz);
 129                 return -1;
 130         }
 131
 132         ASSERT(chip->vendor.send);
 133         rc = chip->vendor.send(chip, (uint8_t *) buf, count);
 134         if (rc < 0) {
 135                 printk(BIOS_DEBUG, "tpm_transmit: tpm_send error\n");
 136                 goto out;
 137         }
 138
 139         if (chip->vendor.irq)
 140                 goto out_recv;
 141
 142         int timeout = 2 * 60 * 1000; /* two minutes timeout */
 143         while (timeout) {
 144                 ASSERT(chip->vendor.status);
 145                 uint8_t status = chip->vendor.status(chip);
 146                 if ((status & chip->vendor.req_complete_mask) ==
 147                     chip->vendor.req_complete_val) {
 148                         goto out_recv;
 149                 }
 150
 151                 if ((status == chip->vendor.req_canceled)) {
 152                         printk(BIOS_DEBUG, "tpm_transmit: Operation Canceled\n");
 153                         rc = -1;
 154                         goto out;
 155                 }
 156                 mdelay(TPM_TIMEOUT);
 157                 timeout--;
 158         }
 159
 160         ASSERT(chip->vendor.cancel);
 161         chip->vendor.cancel(chip);
 162         printk(BIOS_DEBUG, "tpm_transmit: Operation Timed out\n");
 163         rc = -1; //ETIME;
 164         goto out;
 165
 166 out_recv:
 167
 168         rc = chip->vendor.recv(chip, (uint8_t *) buf, TPM_BUFSIZE);
 169         if (rc < 0)
 170                 printk(BIOS_DEBUG, "tpm_transmit: tpm_recv: error %d\n", rc);
 171 out:
 172         return rc;
 173 }
 174
 175 int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 176                 uint8_t *recvbuf, size_t *rbuf_len)
 177 {
 178         uint8_t buf[TPM_BUFSIZE];
 179
 180         if (sizeof(buf) < sbuf_size)
 181                 return -1;
 182
 183         memcpy(buf, sendbuf, sbuf_size);
 184
 185         int len = tpm_transmit(buf, sbuf_size);
 186
 187         if (len < 10) {
 188                 *rbuf_len = 0;
 189                 return -1;
 190         }
 191
 192         if (len > *rbuf_len) {
 193                 *rbuf_len = len;
 194                 return -1;
 195         }
 196
 197         memcpy(recvbuf, buf, len);
 198         *rbuf_len = len;
 199
 200         return 0;
 201 }