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tpm_atmel.c

/*
 * Copyright (C) 2004 IBM Corporation
 *
 * Authors:
 * Leendert van Doorn <leendert@watson.ibm.com>
 * Dave Safford <safford@watson.ibm.com>
 * Reiner Sailer <sailer@watson.ibm.com>
 * Kylene Hall <kjhall@us.ibm.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * Device driver for TCG/TCPA TPM (trusted platform module).
 * Specifications at www.trustedcomputinggroup.org     
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 * 
 */

#include "tpm.h"
#include "tpm_atmel.h"

/* write status bits */
enum tpm_atmel_write_status {
      ATML_STATUS_ABORT = 0x01,
      ATML_STATUS_LASTBYTE = 0x04
};
/* read status bits */
enum tpm_atmel_read_status {
      ATML_STATUS_BUSY = 0x01,
      ATML_STATUS_DATA_AVAIL = 0x02,
      ATML_STATUS_REWRITE = 0x04,
      ATML_STATUS_READY = 0x08
};

static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
      u8 status, *hdr = buf;
      u32 size;
      int i;
      __be32 *native_size;

      /* start reading header */
      if (count < 6)
            return -EIO;

      for (i = 0; i < 6; i++) {
            status = ioread8(chip->vendor.iobase + 1);
            if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
                  dev_err(chip->dev, "error reading header\n");
                  return -EIO;
            }
            *buf++ = ioread8(chip->vendor.iobase);
      }

      /* size of the data received */
      native_size = (__force __be32 *) (hdr + 2);
      size = be32_to_cpu(*native_size);

      if (count < size) {
            dev_err(chip->dev,
                  "Recv size(%d) less than available space\n", size);
            for (; i < size; i++) { /* clear the waiting data anyway */
                  status = ioread8(chip->vendor.iobase + 1);
                  if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
                        dev_err(chip->dev, "error reading data\n");
                        return -EIO;
                  }
            }
            return -EIO;
      }

      /* read all the data available */
      for (; i < size; i++) {
            status = ioread8(chip->vendor.iobase + 1);
            if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
                  dev_err(chip->dev, "error reading data\n");
                  return -EIO;
            }
            *buf++ = ioread8(chip->vendor.iobase);
      }

      /* make sure data available is gone */
      status = ioread8(chip->vendor.iobase + 1);

      if (status & ATML_STATUS_DATA_AVAIL) {
            dev_err(chip->dev, "data available is stuck\n");
            return -EIO;
      }

      return size;
}

static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
{
      int i;

      dev_dbg(chip->dev, "tpm_atml_send:\n");
      for (i = 0; i < count; i++) {
            dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
            iowrite8(buf[i], chip->vendor.iobase);
      }

      return count;
}

static void tpm_atml_cancel(struct tpm_chip *chip)
{
      iowrite8(ATML_STATUS_ABORT, chip->vendor.iobase + 1);
}

static u8 tpm_atml_status(struct tpm_chip *chip)
{
      return ioread8(chip->vendor.iobase + 1);
}

static const struct file_operations atmel_ops = {
      .owner = THIS_MODULE,
      .llseek = no_llseek,
      .open = tpm_open,
      .read = tpm_read,
      .write = tpm_write,
      .release = tpm_release,
};

static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
static DEVICE_ATTR(cancel, S_IWUSR |S_IWGRP, NULL, tpm_store_cancel);

static struct attribute* atmel_attrs[] = {
      &dev_attr_pubek.attr,
      &dev_attr_pcrs.attr,
      &dev_attr_caps.attr,
      &dev_attr_cancel.attr,
      NULL,
};

static struct attribute_group atmel_attr_grp = { .attrs = atmel_attrs };

static const struct tpm_vendor_specific tpm_atmel = {
      .recv = tpm_atml_recv,
      .send = tpm_atml_send,
      .cancel = tpm_atml_cancel,
      .status = tpm_atml_status,
      .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
      .req_complete_val = ATML_STATUS_DATA_AVAIL,
      .req_canceled = ATML_STATUS_READY,
      .attr_group = &atmel_attr_grp,
      .miscdev = { .fops = &atmel_ops, },
};

static struct platform_device *pdev;

static void atml_plat_remove(void)
{
      struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);

      if (chip) {
            if (chip->vendor.have_region)
                  atmel_release_region(chip->vendor.base,
                                   chip->vendor.region_size);
            atmel_put_base_addr(chip->vendor.iobase);
            tpm_remove_hardware(chip->dev);
            platform_device_unregister(pdev);
      }
}

static struct device_driver atml_drv = {
      .name = "tpm_atmel",
      .bus = &platform_bus_type,
      .owner = THIS_MODULE,
      .suspend = tpm_pm_suspend,
      .resume = tpm_pm_resume,
};

static int __init init_atmel(void)
{
      int rc = 0;
      void __iomem *iobase = NULL;
      int have_region, region_size;
      unsigned long base;
      struct  tpm_chip *chip;

      rc = driver_register(&atml_drv);
      if (rc)
            return rc;

      if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
            rc = -ENODEV;
            goto err_unreg_drv;
      }

      have_region =
          (atmel_request_region
           (tpm_atmel.base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;

      pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
      if (IS_ERR(pdev)) {
            rc = PTR_ERR(pdev);
            goto err_rel_reg;
      }

      if (!(chip = tpm_register_hardware(&pdev->dev, &tpm_atmel))) {
            rc = -ENODEV;
            goto err_unreg_dev;
      }

      chip->vendor.iobase = iobase;
      chip->vendor.base = base;
      chip->vendor.have_region = have_region;
      chip->vendor.region_size = region_size;

      return 0;

err_unreg_dev:
      platform_device_unregister(pdev);
err_rel_reg:
      atmel_put_base_addr(iobase);
      if (have_region)
            atmel_release_region(base,
                             region_size);
err_unreg_drv:
      driver_unregister(&atml_drv);
      return rc;
}

static void __exit cleanup_atmel(void)
{
      driver_unregister(&atml_drv);
      atml_plat_remove();
}

module_init(init_atmel);
module_exit(cleanup_atmel);

MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");

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