drivers/char/tpm/tpm_atmel.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  *
   4  * Authors:
   5  * Leendert van Doorn <[email protected]>
   6  * Dave Safford <[email protected]>
   7  * Reiner Sailer <[email protected]>
   8  * Kylene Hall <[email protected]>
   9  *
  10  * Maintained by: <[email protected]>
  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 = ioread8(chip->vendor.iobase + 1);
  51                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  52                         dev_err(chip->dev, "error reading header\n");
  53                         return -EIO;
  54                 }
  55                 *buf++ = ioread8(chip->vendor.iobase);
  56         }
  57
  58         /* size of the data received */
  59         native_size = (__force __be32 *) (hdr + 2);
  60         size = be32_to_cpu(*native_size);
  61
  62         if (count < size) {
  63                 dev_err(chip->dev,
  64                         "Recv size(%d) less than available space\n", size);
  65                 for (; i < size; i++) { /* clear the waiting data anyway */
  66                         status = ioread8(chip->vendor.iobase + 1);
  67                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  68                                 dev_err(chip->dev, "error reading data\n");
  69                                 return -EIO;
  70                         }
  71                 }
  72                 return -EIO;
  73         }
  74
  75         /* read all the data available */
  76         for (; i < size; i++) {
  77                 status = ioread8(chip->vendor.iobase + 1);
  78                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  79                         dev_err(chip->dev, "error reading data\n");
  80                         return -EIO;
  81                 }
  82                 *buf++ = ioread8(chip->vendor.iobase);
  83         }
  84
  85         /* make sure data available is gone */
  86         status = ioread8(chip->vendor.iobase + 1);
  87
  88         if (status & ATML_STATUS_DATA_AVAIL) {
  89                 dev_err(chip->dev, "data available is stuck\n");
  90                 return -EIO;
  91         }
  92
  93         return size;
  94 }
  95
  96 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
  97 {
  98         int i;
  99
 100         dev_dbg(chip->dev, "tpm_atml_send:\n");
 101         for (i = 0; i < count; i++) {
 102                 dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
 103                 iowrite8(buf[i], chip->vendor.iobase);
 104         }
 105
 106         return count;
 107 }
 108
 109 static void tpm_atml_cancel(struct tpm_chip *chip)
 110 {
 111         iowrite8(ATML_STATUS_ABORT, chip->vendor.iobase + 1);
 112 }
 113
 114 static u8 tpm_atml_status(struct tpm_chip *chip)
 115 {
 116         return ioread8(chip->vendor.iobase + 1);
 117 }
 118
 119 static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
 120 {
 121         return (status == ATML_STATUS_READY);
 122 }
 123
 124 static const struct file_operations atmel_ops = {
 125         .owner = THIS_MODULE,
 126         .llseek = no_llseek,
 127         .open = tpm_open,
 128         .read = tpm_read,
 129         .write = tpm_write,
 130         .release = tpm_release,
 131 };
 132
 133 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
 134 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
 135 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
 136 static DEVICE_ATTR(cancel, S_IWUSR |S_IWGRP, NULL, tpm_store_cancel);
 137
 138 static struct attribute* atmel_attrs[] = {
 139         &dev_attr_pubek.attr,
 140         &dev_attr_pcrs.attr,
 141         &dev_attr_caps.attr,
 142         &dev_attr_cancel.attr,
 143         NULL,
 144 };
 145
 146 static struct attribute_group atmel_attr_grp = { .attrs = atmel_attrs };
 147
 148 static const struct tpm_vendor_specific tpm_atmel = {
 149         .recv = tpm_atml_recv,
 150         .send = tpm_atml_send,
 151         .cancel = tpm_atml_cancel,
 152         .status = tpm_atml_status,
 153         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 154         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 155         .req_canceled = tpm_atml_req_canceled,
 156         .attr_group = &atmel_attr_grp,
 157         .miscdev = { .fops = &atmel_ops, },
 158 };
 159
 160 static struct platform_device *pdev;
 161
 162 static void atml_plat_remove(void)
 163 {
 164         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 165
 166         if (chip) {
 167                 if (chip->vendor.have_region)
 168                         atmel_release_region(chip->vendor.base,
 169                                              chip->vendor.region_size);
 170                 atmel_put_base_addr(chip->vendor.iobase);
 171                 tpm_remove_hardware(chip->dev);
 172                 platform_device_unregister(pdev);
 173         }
 174 }
 175
 176 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
 177
 178 static struct platform_driver atml_drv = {
 179         .driver = {
 180                 .name = "tpm_atmel",
 181                 .owner          = THIS_MODULE,
 182                 .pm             = &tpm_atml_pm,
 183         },
 184 };
 185
 186 static int __init init_atmel(void)
 187 {
 188         int rc = 0;
 189         void __iomem *iobase = NULL;
 190         int have_region, region_size;
 191         unsigned long base;
 192         struct  tpm_chip *chip;
 193
 194         rc = platform_driver_register(&atml_drv);
 195         if (rc)
 196                 return rc;
 197
 198         if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
 199                 rc = -ENODEV;
 200                 goto err_unreg_drv;
 201         }
 202
 203         have_region =
 204             (atmel_request_region
 205              (tpm_atmel.base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
 206
 207         pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
 208         if (IS_ERR(pdev)) {
 209                 rc = PTR_ERR(pdev);
 210                 goto err_rel_reg;
 211         }
 212
 213         if (!(chip = tpm_register_hardware(&pdev->dev, &tpm_atmel))) {
 214                 rc = -ENODEV;
 215                 goto err_unreg_dev;
 216         }
 217
 218         chip->vendor.iobase = iobase;
 219         chip->vendor.base = base;
 220         chip->vendor.have_region = have_region;
 221         chip->vendor.region_size = region_size;
 222
 223         return 0;
 224
 225 err_unreg_dev:
 226         platform_device_unregister(pdev);
 227 err_rel_reg:
 228         atmel_put_base_addr(iobase);
 229         if (have_region)
 230                 atmel_release_region(base,
 231                                      region_size);
 232 err_unreg_drv:
 233         platform_driver_unregister(&atml_drv);
 234         return rc;
 235 }
 236
 237 static void __exit cleanup_atmel(void)
 238 {
 239         platform_driver_unregister(&atml_drv);
 240         atml_plat_remove();
 241 }
 242
 243 module_init(init_atmel);
 244 module_exit(cleanup_atmel);
 245
 246 MODULE_AUTHOR("Leendert van Doorn ([email protected])");
 247 MODULE_DESCRIPTION("TPM Driver");
 248 MODULE_VERSION("2.0");
 249 MODULE_LICENSE("GPL");