drivers/char/tpm/tpm_atmel.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2004 IBM Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <leendert@watson.ibm.com>
   7  * Dave Safford <safford@watson.ibm.com>
   8  * Reiner Sailer <sailer@watson.ibm.com>
   9  * Kylene Hall <kjhall@us.ibm.com>
  10  *
  11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  15  */
  16
  17 #include "tpm.h"
  18 #include "tpm_atmel.h"
  19
  20 /* write status bits */
  21 enum tpm_atmel_write_status {
  22         ATML_STATUS_ABORT = 0x01,
  23         ATML_STATUS_LASTBYTE = 0x04
  24 };
  25 /* read status bits */
  26 enum tpm_atmel_read_status {
  27         ATML_STATUS_BUSY = 0x01,
  28         ATML_STATUS_DATA_AVAIL = 0x02,
  29         ATML_STATUS_REWRITE = 0x04,
  30         ATML_STATUS_READY = 0x08
  31 };
  32
  33 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  34 {
  35         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
  36         u8 status, *hdr = buf;
  37         u32 size;
  38         int i;
  39         __be32 *native_size;
  40
  41         /* start reading header */
  42         if (count < 6)
  43                 return -EIO;
  44
  45         for (i = 0; i < 6; i++) {
  46                 status = ioread8(priv->iobase + 1);
  47                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  48                         dev_err(&chip->dev, "error reading header\n");
  49                         return -EIO;
  50                 }
  51                 *buf++ = ioread8(priv->iobase);
  52         }
  53
  54         /* size of the data received */
  55         native_size = (__force __be32 *) (hdr + 2);
  56         size = be32_to_cpu(*native_size);
  57
  58         if (count < size) {
  59                 dev_err(&chip->dev,
  60                         "Recv size(%d) less than available space\n", size);
  61                 for (; i < size; i++) { /* clear the waiting data anyway */
  62                         status = ioread8(priv->iobase + 1);
  63                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  64                                 dev_err(&chip->dev, "error reading data\n");
  65                                 return -EIO;
  66                         }
  67                 }
  68                 return -EIO;
  69         }
  70
  71         /* read all the data available */
  72         for (; i < size; i++) {
  73                 status = ioread8(priv->iobase + 1);
  74                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  75                         dev_err(&chip->dev, "error reading data\n");
  76                         return -EIO;
  77                 }
  78                 *buf++ = ioread8(priv->iobase);
  79         }
  80
  81         /* make sure data available is gone */
  82         status = ioread8(priv->iobase + 1);
  83
  84         if (status & ATML_STATUS_DATA_AVAIL) {
  85                 dev_err(&chip->dev, "data available is stuck\n");
  86                 return -EIO;
  87         }
  88
  89         return size;
  90 }
  91
  92 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
  93 {
  94         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
  95         int i;
  96
  97         dev_dbg(&chip->dev, "tpm_atml_send:\n");
  98         for (i = 0; i < count; i++) {
  99                 dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
 100                 iowrite8(buf[i], priv->iobase);
 101         }
 102
 103         return 0;
 104 }
 105
 106 static void tpm_atml_cancel(struct tpm_chip *chip)
 107 {
 108         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 109
 110         iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
 111 }
 112
 113 static u8 tpm_atml_status(struct tpm_chip *chip)
 114 {
 115         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 116
 117         return ioread8(priv->iobase + 1);
 118 }
 119
 120 static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
 121 {
 122         return (status == ATML_STATUS_READY);
 123 }
 124
 125 static const struct tpm_class_ops tpm_atmel = {
 126         .recv = tpm_atml_recv,
 127         .send = tpm_atml_send,
 128         .cancel = tpm_atml_cancel,
 129         .status = tpm_atml_status,
 130         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 131         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 132         .req_canceled = tpm_atml_req_canceled,
 133 };
 134
 135 static struct platform_device *pdev;
 136
 137 static void atml_plat_remove(void)
 138 {
 139         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 140         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 141
 142         tpm_chip_unregister(chip);
 143         if (priv->have_region)
 144                 atmel_release_region(priv->base, priv->region_size);
 145         atmel_put_base_addr(priv->iobase);
 146         platform_device_unregister(pdev);
 147 }
 148
 149 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
 150
 151 static struct platform_driver atml_drv = {
 152         .driver = {
 153                 .name = "tpm_atmel",
 154                 .pm             = &tpm_atml_pm,
 155         },
 156 };
 157
 158 static int __init init_atmel(void)
 159 {
 160         int rc = 0;
 161         void __iomem *iobase = NULL;
 162         int have_region, region_size;
 163         unsigned long base;
 164         struct  tpm_chip *chip;
 165         struct tpm_atmel_priv *priv;
 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         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 187         if (!priv) {
 188                 rc = -ENOMEM;
 189                 goto err_unreg_dev;
 190         }
 191
 192         priv->iobase = iobase;
 193         priv->base = base;
 194         priv->have_region = have_region;
 195         priv->region_size = region_size;
 196
 197         chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
 198         if (IS_ERR(chip)) {
 199                 rc = PTR_ERR(chip);
 200                 goto err_unreg_dev;
 201         }
 202
 203         dev_set_drvdata(&chip->dev, priv);
 204
 205         rc = tpm_chip_register(chip);
 206         if (rc)
 207                 goto err_unreg_dev;
 208
 209         return 0;
 210
 211 err_unreg_dev:
 212         platform_device_unregister(pdev);
 213 err_rel_reg:
 214         atmel_put_base_addr(iobase);
 215         if (have_region)
 216                 atmel_release_region(base,
 217                                      region_size);
 218 err_unreg_drv:
 219         platform_driver_unregister(&atml_drv);
 220         return rc;
 221 }
 222
 223 static void __exit cleanup_atmel(void)
 224 {
 225         platform_driver_unregister(&atml_drv);
 226         atml_plat_remove();
 227 }
 228
 229 module_init(init_atmel);
 230 module_exit(cleanup_atmel);
 231
 232 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 233 MODULE_DESCRIPTION("TPM Driver");
 234 MODULE_VERSION("2.0");
 235 MODULE_LICENSE("GPL");