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         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
  41         u8 status, *hdr = buf;
  42         u32 size;
  43         int i;
  44         __be32 *native_size;
  45
  46         /* start reading header */
  47         if (count < 6)
  48                 return -EIO;
  49
  50         for (i = 0; i < 6; i++) {
  51                 status = ioread8(priv->iobase + 1);
  52                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  53                         dev_err(&chip->dev, "error reading header\n");
  54                         return -EIO;
  55                 }
  56                 *buf++ = ioread8(priv->iobase);
  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 = ioread8(priv->iobase + 1);
  68                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  69                                 dev_err(&chip->dev, "error reading data\n");
  70                                 return -EIO;
  71                         }
  72                 }
  73                 return -EIO;
  74         }
  75
  76         /* read all the data available */
  77         for (; i < size; i++) {
  78                 status = ioread8(priv->iobase + 1);
  79                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  80                         dev_err(&chip->dev, "error reading data\n");
  81                         return -EIO;
  82                 }
  83                 *buf++ = ioread8(priv->iobase);
  84         }
  85
  86         /* make sure data available is gone */
  87         status = ioread8(priv->iobase + 1);
  88
  89         if (status & ATML_STATUS_DATA_AVAIL) {
  90                 dev_err(&chip->dev, "data available is stuck\n");
  91                 return -EIO;
  92         }
  93
  94         return size;
  95 }
  96
  97 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
  98 {
  99         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 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                 iowrite8(buf[i], priv->iobase);
 106         }
 107
 108         return count;
 109 }
 110
 111 static void tpm_atml_cancel(struct tpm_chip *chip)
 112 {
 113         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 114
 115         iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
 116 }
 117
 118 static u8 tpm_atml_status(struct tpm_chip *chip)
 119 {
 120         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 121
 122         return ioread8(priv->iobase + 1);
 123 }
 124
 125 static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
 126 {
 127         return (status == ATML_STATUS_READY);
 128 }
 129
 130 static const struct tpm_class_ops tpm_atmel = {
 131         .recv = tpm_atml_recv,
 132         .send = tpm_atml_send,
 133         .cancel = tpm_atml_cancel,
 134         .status = tpm_atml_status,
 135         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 136         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 137         .req_canceled = tpm_atml_req_canceled,
 138 };
 139
 140 static struct platform_device *pdev;
 141
 142 static void atml_plat_remove(void)
 143 {
 144         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 145         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 146
 147         if (chip) {
 148                 tpm_chip_unregister(chip);
 149                 if (priv->have_region)
 150                         atmel_release_region(priv->base, priv->region_size);
 151                 atmel_put_base_addr(priv->iobase);
 152                 platform_device_unregister(pdev);
 153         }
 154 }
 155
 156 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
 157
 158 static struct platform_driver atml_drv = {
 159         .driver = {
 160                 .name = "tpm_atmel",
 161                 .pm             = &tpm_atml_pm,
 162         },
 163 };
 164
 165 static int __init init_atmel(void)
 166 {
 167         int rc = 0;
 168         void __iomem *iobase = NULL;
 169         int have_region, region_size;
 170         unsigned long base;
 171         struct  tpm_chip *chip;
 172         struct tpm_atmel_priv *priv;
 173
 174         rc = platform_driver_register(&atml_drv);
 175         if (rc)
 176                 return rc;
 177
 178         if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
 179                 rc = -ENODEV;
 180                 goto err_unreg_drv;
 181         }
 182
 183         have_region =
 184             (atmel_request_region
 185              (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
 186
 187         pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
 188         if (IS_ERR(pdev)) {
 189                 rc = PTR_ERR(pdev);
 190                 goto err_rel_reg;
 191         }
 192
 193         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 194         if (!priv) {
 195                 rc = -ENOMEM;
 196                 goto err_unreg_dev;
 197         }
 198
 199         priv->iobase = iobase;
 200         priv->base = base;
 201         priv->have_region = have_region;
 202         priv->region_size = region_size;
 203
 204         chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
 205         if (IS_ERR(chip)) {
 206                 rc = PTR_ERR(chip);
 207                 goto err_unreg_dev;
 208         }
 209
 210         dev_set_drvdata(&chip->dev, priv);
 211
 212         rc = tpm_chip_register(chip);
 213         if (rc)
 214                 goto err_unreg_dev;
 215
 216         return 0;
 217
 218 err_unreg_dev:
 219         platform_device_unregister(pdev);
 220 err_rel_reg:
 221         atmel_put_base_addr(iobase);
 222         if (have_region)
 223                 atmel_release_region(base,
 224                                      region_size);
 225 err_unreg_drv:
 226         platform_driver_unregister(&atml_drv);
 227         return rc;
 228 }
 229
 230 static void __exit cleanup_atmel(void)
 231 {
 232         platform_driver_unregister(&atml_drv);
 233         atml_plat_remove();
 234 }
 235
 236 module_init(init_atmel);
 237 module_exit(cleanup_atmel);
 238
 239 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 240 MODULE_DESCRIPTION("TPM Driver");
 241 MODULE_VERSION("2.0");
 242 MODULE_LICENSE("GPL");