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 #include "tpm_atmel.h"
  24
  25 /* write status bits */
  26 enum tpm_atmel_write_status {
  27         ATML_STATUS_ABORT = 0x01,
  28         ATML_STATUS_LASTBYTE = 0x04
  29 };
  30 /* read status bits */
  31 enum tpm_atmel_read_status {
  32         ATML_STATUS_BUSY = 0x01,
  33         ATML_STATUS_DATA_AVAIL = 0x02,
  34         ATML_STATUS_REWRITE = 0x04,
  35         ATML_STATUS_READY = 0x08
  36 };
  37
  38 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  39 {
  40         u8 status, *hdr = buf;
  41         u32 size;
  42         int i;
  43         __be32 *native_size;
  44
  45         /* start reading header */
  46         if (count < 6)
  47                 return -EIO;
  48
  49         for (i = 0; i < 6; i++) {
  50                 status = atmel_getb(chip, 1);
  51                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  52                         dev_err(chip->dev,
  53                                 "error reading header\n");
  54                         return -EIO;
  55                 }
  56                 *buf++ = atmel_getb(chip, 0);
  57         }
  58
  59         /* size of the data received */
  60         native_size = (__force __be32 *) (hdr + 2);
  61         size = be32_to_cpu(*native_size);
  62
  63         if (count < size) {
  64                 dev_err(chip->dev,
  65                         "Recv size(%d) less than available space\n", size);
  66                 for (; i < size; i++) { /* clear the waiting data anyway */
  67                         status = atmel_getb(chip, 1);
  68                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  69                                 dev_err(chip->dev,
  70                                         "error reading data\n");
  71                                 return -EIO;
  72                         }
  73                 }
  74                 return -EIO;
  75         }
  76
  77         /* read all the data available */
  78         for (; i < size; i++) {
  79                 status = atmel_getb(chip, 1);
  80                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  81                         dev_err(chip->dev,
  82                                 "error reading data\n");
  83                         return -EIO;
  84                 }
  85                 *buf++ = atmel_getb(chip, 0);
  86         }
  87
  88         /* make sure data available is gone */
  89         status = atmel_getb(chip, 1);
  90         if (status & ATML_STATUS_DATA_AVAIL) {
  91                 dev_err(chip->dev, "data available is stuck\n");
  92                 return -EIO;
  93         }
  94
  95         return size;
  96 }
  97
  98 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
  99 {
 100         int i;
 101
 102         dev_dbg(chip->dev, "tpm_atml_send:\n");
 103         for (i = 0; i < count; i++) {
 104                 dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
 105                 atmel_putb(buf[i], chip, 0);
 106         }
 107
 108         return count;
 109 }
 110
 111 static void tpm_atml_cancel(struct tpm_chip *chip)
 112 {
 113         atmel_putb(ATML_STATUS_ABORT, chip, 1);
 114 }
 115
 116 static u8 tpm_atml_status(struct tpm_chip *chip)
 117 {
 118         return atmel_getb(chip, 1);
 119 }
 120
 121 static struct file_operations atmel_ops = {
 122         .owner = THIS_MODULE,
 123         .llseek = no_llseek,
 124         .open = tpm_open,
 125         .read = tpm_read,
 126         .write = tpm_write,
 127         .release = tpm_release,
 128 };
 129
 130 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
 131 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
 132 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
 133 static DEVICE_ATTR(cancel, S_IWUSR |S_IWGRP, NULL, tpm_store_cancel);
 134
 135 static struct attribute* atmel_attrs[] = {
 136         &dev_attr_pubek.attr,
 137         &dev_attr_pcrs.attr,
 138         &dev_attr_caps.attr,
 139         &dev_attr_cancel.attr,
 140         NULL,
 141 };
 142
 143 static struct attribute_group atmel_attr_grp = { .attrs = atmel_attrs };
 144
 145 static struct tpm_vendor_specific tpm_atmel = {
 146         .recv = tpm_atml_recv,
 147         .send = tpm_atml_send,
 148         .cancel = tpm_atml_cancel,
 149         .status = tpm_atml_status,
 150         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 151         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 152         .req_canceled = ATML_STATUS_READY,
 153         .attr_group = &atmel_attr_grp,
 154         .miscdev = { .fops = &atmel_ops, },
 155 };
 156
 157 static struct platform_device *pdev;
 158
 159 static void atml_plat_remove(void)
 160 {
 161         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 162
 163         if (chip) {
 164                 if (chip->vendor->have_region)
 165                         atmel_release_region(chip->vendor->base, chip->vendor->region_size);
 166                 atmel_put_base_addr(chip->vendor);
 167                 tpm_remove_hardware(chip->dev);
 168                 platform_device_unregister(pdev);
 169         }
 170 }
 171
 172 static struct device_driver atml_drv = {
 173         .name = "tpm_atmel",
 174         .bus = &platform_bus_type,
 175         .owner = THIS_MODULE,
 176         .suspend = tpm_pm_suspend,
 177         .resume = tpm_pm_resume,
 178 };
 179
 180 static int __init init_atmel(void)
 181 {
 182         int rc = 0;
 183
 184         driver_register(&atml_drv);
 185
 186         if (atmel_get_base_addr(&tpm_atmel) != 0) {
 187                 rc = -ENODEV;
 188                 goto err_unreg_drv;
 189         }
 190
 191         tpm_atmel.have_region = (atmel_request_region( tpm_atmel.base, tpm_atmel.region_size, "tpm_atmel0") == NULL) ? 0 : 1;
 192
 193         if (IS_ERR(pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0 ))) {
 194                 rc = PTR_ERR(pdev);
 195                 goto err_rel_reg;
 196         }
 197
 198         if ((rc = tpm_register_hardware(&pdev->dev, &tpm_atmel)) < 0)
 199                 goto err_unreg_dev;
 200         return 0;
 201
 202 err_unreg_dev:
 203         platform_device_unregister(pdev);
 204 err_rel_reg:
 205         if (tpm_atmel.have_region)
 206                 atmel_release_region(tpm_atmel.base, tpm_atmel.region_size);
 207         atmel_put_base_addr(&tpm_atmel);
 208 err_unreg_drv:
 209         driver_unregister(&atml_drv);
 210         return rc;
 211 }
 212
 213 static void __exit cleanup_atmel(void)
 214 {
 215         driver_unregister(&atml_drv);
 216         atml_plat_remove();
 217 }
 218
 219 module_init(init_atmel);
 220 module_exit(cleanup_atmel);
 221
 222 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 223 MODULE_DESCRIPTION("TPM Driver");
 224 MODULE_VERSION("2.0");
 225 MODULE_LICENSE("GPL");