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 = 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 tpm_class_ops tpm_atmel = {
 125         .recv = tpm_atml_recv,
 126         .send = tpm_atml_send,
 127         .cancel = tpm_atml_cancel,
 128         .status = tpm_atml_status,
 129         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 130         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 131         .req_canceled = tpm_atml_req_canceled,
 132 };
 133
 134 static struct platform_device *pdev;
 135
 136 static void atml_plat_remove(void)
 137 {
 138         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 139
 140         if (chip) {
 141                 if (chip->vendor.have_region)
 142                         atmel_release_region(chip->vendor.base,
 143                                              chip->vendor.region_size);
 144                 atmel_put_base_addr(chip->vendor.iobase);
 145                 tpm_remove_hardware(chip->dev);
 146                 platform_device_unregister(pdev);
 147         }
 148 }
 149
 150 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
 151
 152 static struct platform_driver atml_drv = {
 153         .driver = {
 154                 .name = "tpm_atmel",
 155                 .pm             = &tpm_atml_pm,
 156         },
 157 };
 158
 159 static int __init init_atmel(void)
 160 {
 161         int rc = 0;
 162         void __iomem *iobase = NULL;
 163         int have_region, region_size;
 164         unsigned long base;
 165         struct  tpm_chip *chip;
 166
 167         rc = platform_driver_register(&atml_drv);
 168         if (rc)
 169                 return rc;
 170
 171         if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
 172                 rc = -ENODEV;
 173                 goto err_unreg_drv;
 174         }
 175
 176         have_region =
 177             (atmel_request_region
 178              (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
 179
 180         pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
 181         if (IS_ERR(pdev)) {
 182                 rc = PTR_ERR(pdev);
 183                 goto err_rel_reg;
 184         }
 185
 186         if (!(chip = tpm_register_hardware(&pdev->dev, &tpm_atmel))) {
 187                 rc = -ENODEV;
 188                 goto err_unreg_dev;
 189         }
 190
 191         chip->vendor.iobase = iobase;
 192         chip->vendor.base = base;
 193         chip->vendor.have_region = have_region;
 194         chip->vendor.region_size = region_size;
 195
 196         return 0;
 197
 198 err_unreg_dev:
 199         platform_device_unregister(pdev);
 200 err_rel_reg:
 201         atmel_put_base_addr(iobase);
 202         if (have_region)
 203                 atmel_release_region(base,
 204                                      region_size);
 205 err_unreg_drv:
 206         platform_driver_unregister(&atml_drv);
 207         return rc;
 208 }
 209
 210 static void __exit cleanup_atmel(void)
 211 {
 212         platform_driver_unregister(&atml_drv);
 213         atml_plat_remove();
 214 }
 215
 216 module_init(init_atmel);
 217 module_exit(cleanup_atmel);
 218
 219 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 220 MODULE_DESCRIPTION("TPM Driver");
 221 MODULE_VERSION("2.0");
 222 MODULE_LICENSE("GPL");