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 <[email protected]>
   7  * Dave Safford <[email protected]>
   8  * Reiner Sailer <[email protected]>
   9  * Kylene Hall <[email protected]>
  10  *
  11  * Maintained by: <[email protected]>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  15  */
  16
  17 #include "tpm.h"
  18
  19 struct tpm_atmel_priv {
  20         int region_size;
  21         int have_region;
  22         unsigned long base;
  23         void __iomem *iobase;
  24 };
  25
  26 #define atmel_getb(chip, offset) inb(atmel_get_priv(chip)->base + (offset))
  27 #define atmel_putb(val, chip, offset) \
  28         outb(val, atmel_get_priv(chip)->base + (offset))
  29 #define atmel_request_region request_region
  30 #define atmel_release_region release_region
  31 /* Atmel definitions */
  32 enum tpm_atmel_addr {
  33         TPM_ATMEL_BASE_ADDR_LO = 0x08,
  34         TPM_ATMEL_BASE_ADDR_HI = 0x09
  35 };
  36
  37 static inline int tpm_read_index(int base, int index)
  38 {
  39         outb(index, base);
  40         return inb(base + 1) & 0xFF;
  41 }
  42
  43 /* Verify this is a 1.1 Atmel TPM */
  44 static int atmel_verify_tpm11(void)
  45 {
  46         /* verify that it is an Atmel part */
  47         if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
  48             tpm_read_index(TPM_ADDR, 5) != 'T' ||
  49             tpm_read_index(TPM_ADDR, 6) != 'M' ||
  50             tpm_read_index(TPM_ADDR, 7) != 'L')
  51                 return 1;
  52
  53         /* query chip for its version number */
  54         if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
  55             tpm_read_index(TPM_ADDR, 0x01) != 1)
  56                 return 1;
  57
  58         /* This is an atmel supported part */
  59         return 0;
  60 }
  61
  62 /* Determine where to talk to device */
  63 static void __iomem *atmel_get_base_addr(unsigned long *base, int *region_size)
  64 {
  65         int lo, hi;
  66
  67         if (atmel_verify_tpm11() != 0)
  68                 return NULL;
  69
  70         lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
  71         hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
  72
  73         *base = (hi << 8) | lo;
  74         *region_size = 2;
  75
  76         return ioport_map(*base, *region_size);
  77 }
  78
  79 /* write status bits */
  80 enum tpm_atmel_write_status {
  81         ATML_STATUS_ABORT = 0x01,
  82         ATML_STATUS_LASTBYTE = 0x04
  83 };
  84 /* read status bits */
  85 enum tpm_atmel_read_status {
  86         ATML_STATUS_BUSY = 0x01,
  87         ATML_STATUS_DATA_AVAIL = 0x02,
  88         ATML_STATUS_REWRITE = 0x04,
  89         ATML_STATUS_READY = 0x08
  90 };
  91
  92 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  93 {
  94         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
  95         u8 status, *hdr = buf;
  96         u32 size;
  97         int i;
  98         __be32 *native_size;
  99
 100         /* start reading header */
 101         if (count < 6)
 102                 return -EIO;
 103
 104         for (i = 0; i < 6; i++) {
 105                 status = ioread8(priv->iobase + 1);
 106                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
 107                         dev_err(&chip->dev, "error reading header\n");
 108                         return -EIO;
 109                 }
 110                 *buf++ = ioread8(priv->iobase);
 111         }
 112
 113         /* size of the data received */
 114         native_size = (__force __be32 *) (hdr + 2);
 115         size = be32_to_cpu(*native_size);
 116
 117         if (count < size) {
 118                 dev_err(&chip->dev,
 119                         "Recv size(%d) less than available space\n", size);
 120                 for (; i < size; i++) { /* clear the waiting data anyway */
 121                         status = ioread8(priv->iobase + 1);
 122                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
 123                                 dev_err(&chip->dev, "error reading data\n");
 124                                 return -EIO;
 125                         }
 126                 }
 127                 return -EIO;
 128         }
 129
 130         /* read all the data available */
 131         for (; i < size; i++) {
 132                 status = ioread8(priv->iobase + 1);
 133                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
 134                         dev_err(&chip->dev, "error reading data\n");
 135                         return -EIO;
 136                 }
 137                 *buf++ = ioread8(priv->iobase);
 138         }
 139
 140         /* make sure data available is gone */
 141         status = ioread8(priv->iobase + 1);
 142
 143         if (status & ATML_STATUS_DATA_AVAIL) {
 144                 dev_err(&chip->dev, "data available is stuck\n");
 145                 return -EIO;
 146         }
 147
 148         return size;
 149 }
 150
 151 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
 152 {
 153         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 154         int i;
 155
 156         dev_dbg(&chip->dev, "tpm_atml_send:\n");
 157         for (i = 0; i < count; i++) {
 158                 dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
 159                 iowrite8(buf[i], priv->iobase);
 160         }
 161
 162         return 0;
 163 }
 164
 165 static void tpm_atml_cancel(struct tpm_chip *chip)
 166 {
 167         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 168
 169         iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
 170 }
 171
 172 static u8 tpm_atml_status(struct tpm_chip *chip)
 173 {
 174         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 175
 176         return ioread8(priv->iobase + 1);
 177 }
 178
 179 static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
 180 {
 181         return (status == ATML_STATUS_READY);
 182 }
 183
 184 static const struct tpm_class_ops tpm_atmel = {
 185         .recv = tpm_atml_recv,
 186         .send = tpm_atml_send,
 187         .cancel = tpm_atml_cancel,
 188         .status = tpm_atml_status,
 189         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 190         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 191         .req_canceled = tpm_atml_req_canceled,
 192 };
 193
 194 static struct platform_device *pdev;
 195
 196 static void atml_plat_remove(void)
 197 {
 198         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 199         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 200
 201         tpm_chip_unregister(chip);
 202         if (priv->have_region)
 203                 atmel_release_region(priv->base, priv->region_size);
 204         platform_device_unregister(pdev);
 205 }
 206
 207 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
 208
 209 static struct platform_driver atml_drv = {
 210         .driver = {
 211                 .name = "tpm_atmel",
 212                 .pm             = &tpm_atml_pm,
 213         },
 214 };
 215
 216 static int __init init_atmel(void)
 217 {
 218         int rc = 0;
 219         void __iomem *iobase = NULL;
 220         int have_region, region_size;
 221         unsigned long base;
 222         struct  tpm_chip *chip;
 223         struct tpm_atmel_priv *priv;
 224
 225         rc = platform_driver_register(&atml_drv);
 226         if (rc)
 227                 return rc;
 228
 229         if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
 230                 rc = -ENODEV;
 231                 goto err_unreg_drv;
 232         }
 233
 234         have_region =
 235             (atmel_request_region
 236              (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
 237
 238         pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
 239         if (IS_ERR(pdev)) {
 240                 rc = PTR_ERR(pdev);
 241                 goto err_rel_reg;
 242         }
 243
 244         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 245         if (!priv) {
 246                 rc = -ENOMEM;
 247                 goto err_unreg_dev;
 248         }
 249
 250         priv->iobase = iobase;
 251         priv->base = base;
 252         priv->have_region = have_region;
 253         priv->region_size = region_size;
 254
 255         chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
 256         if (IS_ERR(chip)) {
 257                 rc = PTR_ERR(chip);
 258                 goto err_unreg_dev;
 259         }
 260
 261         dev_set_drvdata(&chip->dev, priv);
 262
 263         rc = tpm_chip_register(chip);
 264         if (rc)
 265                 goto err_unreg_dev;
 266
 267         return 0;
 268
 269 err_unreg_dev:
 270         platform_device_unregister(pdev);
 271 err_rel_reg:
 272         if (have_region)
 273                 atmel_release_region(base,
 274                                      region_size);
 275 err_unreg_drv:
 276         platform_driver_unregister(&atml_drv);
 277         return rc;
 278 }
 279
 280 static void __exit cleanup_atmel(void)
 281 {
 282         platform_driver_unregister(&atml_drv);
 283         atml_plat_remove();
 284 }
 285
 286 module_init(init_atmel);
 287 module_exit(cleanup_atmel);
 288
 289 MODULE_AUTHOR("Leendert van Doorn <[email protected]>");
 290 MODULE_DESCRIPTION("TPM Driver");
 291 MODULE_VERSION("2.0");
 292 MODULE_LICENSE("GPL");