drivers/char/tpm/tpm_atmel.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  *
   4  * Authors:
   5  * Leendert van Doorn <leendert@watson.ibm.com>
   6  * Dave Safford <safford@watson.ibm.com>
   7  * Reiner Sailer <sailer@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 program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License as
  17  * published by the Free Software Foundation, version 2 of the
  18  * License.
  19  *
  20  */
  21
  22 #include "tpm.h"
  23
  24 /* Atmel definitions */
  25 enum tpm_atmel_addr {
  26         TPM_ATMEL_BASE_ADDR_LO = 0x08,
  27         TPM_ATMEL_BASE_ADDR_HI = 0x09
  28 };
  29
  30 /* write status bits */
  31 enum tpm_atmel_write_status {
  32         ATML_STATUS_ABORT = 0x01,
  33         ATML_STATUS_LASTBYTE = 0x04
  34 };
  35 /* read status bits */
  36 enum tpm_atmel_read_status {
  37         ATML_STATUS_BUSY = 0x01,
  38         ATML_STATUS_DATA_AVAIL = 0x02,
  39         ATML_STATUS_REWRITE = 0x04,
  40         ATML_STATUS_READY = 0x08
  41 };
  42
  43 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  44 {
  45         u8 status, *hdr = buf;
  46         u32 size;
  47         int i;
  48         __be32 *native_size;
  49
  50         /* start reading header */
  51         if (count < 6)
  52                 return -EIO;
  53
  54         for (i = 0; i < 6; i++) {
  55                 status = inb(chip->vendor->base + 1);
  56                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  57                         dev_err(chip->dev,
  58                                 "error reading header\n");
  59                         return -EIO;
  60                 }
  61                 *buf++ = inb(chip->vendor->base);
  62         }
  63
  64         /* size of the data received */
  65         native_size = (__force __be32 *) (hdr + 2);
  66         size = be32_to_cpu(*native_size);
  67
  68         if (count < size) {
  69                 dev_err(chip->dev,
  70                         "Recv size(%d) less than available space\n", size);
  71                 for (; i < size; i++) { /* clear the waiting data anyway */
  72                         status = inb(chip->vendor->base + 1);
  73                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  74                                 dev_err(chip->dev,
  75                                         "error reading data\n");
  76                                 return -EIO;
  77                         }
  78                 }
  79                 return -EIO;
  80         }
  81
  82         /* read all the data available */
  83         for (; i < size; i++) {
  84                 status = inb(chip->vendor->base + 1);
  85                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  86                         dev_err(chip->dev,
  87                                 "error reading data\n");
  88                         return -EIO;
  89                 }
  90                 *buf++ = inb(chip->vendor->base);
  91         }
  92
  93         /* make sure data available is gone */
  94         status = inb(chip->vendor->base + 1);
  95         if (status & ATML_STATUS_DATA_AVAIL) {
  96                 dev_err(chip->dev, "data available is stuck\n");
  97                 return -EIO;
  98         }
  99
 100         return size;
 101 }
 102
 103 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
 104 {
 105         int i;
 106
 107         dev_dbg(chip->dev, "tpm_atml_send:\n");
 108         for (i = 0; i < count; i++) {
 109                 dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
 110                 outb(buf[i], chip->vendor->base);
 111         }
 112
 113         return count;
 114 }
 115
 116 static void tpm_atml_cancel(struct tpm_chip *chip)
 117 {
 118         outb(ATML_STATUS_ABORT, chip->vendor->base + 1);
 119 }
 120
 121 static u8 tpm_atml_status(struct tpm_chip *chip)
 122 {
 123         return inb(chip->vendor->base + 1);
 124 }
 125
 126 static struct file_operations atmel_ops = {
 127         .owner = THIS_MODULE,
 128         .llseek = no_llseek,
 129         .open = tpm_open,
 130         .read = tpm_read,
 131         .write = tpm_write,
 132         .release = tpm_release,
 133 };
 134
 135 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
 136 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
 137 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
 138 static DEVICE_ATTR(cancel, S_IWUSR |S_IWGRP, NULL, tpm_store_cancel);
 139
 140 static struct attribute* atmel_attrs[] = {
 141         &dev_attr_pubek.attr,
 142         &dev_attr_pcrs.attr,
 143         &dev_attr_caps.attr,
 144         &dev_attr_cancel.attr,
 145         NULL,
 146 };
 147
 148 static struct attribute_group atmel_attr_grp = { .attrs = atmel_attrs };
 149
 150 static struct tpm_vendor_specific tpm_atmel = {
 151         .recv = tpm_atml_recv,
 152         .send = tpm_atml_send,
 153         .cancel = tpm_atml_cancel,
 154         .status = tpm_atml_status,
 155         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 156         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 157         .req_canceled = ATML_STATUS_READY,
 158         .attr_group = &atmel_attr_grp,
 159         .miscdev = { .fops = &atmel_ops, },
 160 };
 161
 162 static struct platform_device *pdev;
 163
 164 static void __devexit tpm_atml_remove(struct device *dev)
 165 {
 166         struct tpm_chip *chip = dev_get_drvdata(dev);
 167         if (chip) {
 168                 release_region(chip->vendor->base, 2);
 169                 tpm_remove_hardware(chip->dev);
 170         }
 171 }
 172
 173 static struct device_driver atml_drv = {
 174         .name = "tpm_atmel",
 175         .bus = &platform_bus_type,
 176         .owner = THIS_MODULE,
 177         .suspend = tpm_pm_suspend,
 178         .resume = tpm_pm_resume,
 179 };
 180
 181 static int __init init_atmel(void)
 182 {
 183         int rc = 0;
 184         int lo, hi;
 185
 186         driver_register(&atml_drv);
 187
 188         lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
 189         hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
 190
 191         tpm_atmel.base = (hi<<8)|lo;
 192
 193         /* verify that it is an Atmel part */
 194         if (tpm_read_index(TPM_ADDR, 4) != 'A' || tpm_read_index(TPM_ADDR, 5) != 'T'
 195             || tpm_read_index(TPM_ADDR, 6) != 'M' || tpm_read_index(TPM_ADDR, 7) != 'L') {
 196                 return -ENODEV;
 197         }
 198
 199         /* verify chip version number is 1.1 */
 200         if (    (tpm_read_index(TPM_ADDR, 0x00) != 0x01) ||
 201                 (tpm_read_index(TPM_ADDR, 0x01) != 0x01 ))
 202                 return -ENODEV;
 203
 204         pdev = kzalloc(sizeof(struct platform_device), GFP_KERNEL);
 205         if ( !pdev )
 206                 return -ENOMEM;
 207
 208         pdev->name = "tpm_atmel0";
 209         pdev->id = -1;
 210         pdev->num_resources = 0;
 211         pdev->dev.release = tpm_atml_remove;
 212         pdev->dev.driver = &atml_drv;
 213
 214         if ((rc = platform_device_register(pdev)) < 0) {
 215                 kfree(pdev);
 216                 pdev = NULL;
 217                 return rc;
 218         }
 219
 220         if (request_region(tpm_atmel.base, 2, "tpm_atmel0") == NULL ) {
 221                 platform_device_unregister(pdev);
 222                 kfree(pdev);
 223                 pdev = NULL;
 224                 return -EBUSY;
 225         }
 226
 227         if ((rc = tpm_register_hardware(&pdev->dev, &tpm_atmel)) < 0) {
 228                 release_region(tpm_atmel.base, 2);
 229                 platform_device_unregister(pdev);
 230                 kfree(pdev);
 231                 pdev = NULL;
 232                 return rc;
 233         }
 234
 235         dev_info(&pdev->dev, "Atmel TPM 1.1, Base Address: 0x%x\n",
 236                         tpm_atmel.base);
 237         return 0;
 238 }
 239
 240 static void __exit cleanup_atmel(void)
 241 {
 242         if (pdev) {
 243                 tpm_atml_remove(&pdev->dev);
 244                 platform_device_unregister(pdev);
 245                 kfree(pdev);
 246                 pdev = NULL;
 247         }
 248
 249         driver_unregister(&atml_drv);
 250 }
 251
 252 module_init(init_atmel);
 253 module_exit(cleanup_atmel);
 254
 255 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 256 MODULE_DESCRIPTION("TPM Driver");
 257 MODULE_VERSION("2.0");
 258 MODULE_LICENSE("GPL");