linux/drivers/char/hw_random/tpm-rng.c
Kent Yoder 578b016fdc hw_random: add support for the TPM chip as a hardware RNG source
This driver will make use of any available TPM chip on the system as a
hwrng source.

Acked-by: David Safford <safford@linux.vnet.ibm.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
2012-08-22 11:11:41 -05:00

51 lines
1.4 KiB
C

/*
* Copyright (C) 2012 Kent Yoder IBM Corporation
*
* HWRNG interfaces to pull RNG data from a TPM
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/hw_random.h>
#include <linux/tpm.h>
#define MODULE_NAME "tpm-rng"
static int tpm_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
return tpm_get_random(TPM_ANY_NUM, data, max);
}
static struct hwrng tpm_rng = {
.name = MODULE_NAME,
.read = tpm_rng_read,
};
static int __init rng_init(void)
{
return hwrng_register(&tpm_rng);
}
module_init(rng_init);
static void __exit rng_exit(void)
{
hwrng_unregister(&tpm_rng);
}
module_exit(rng_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Kent Yoder <key@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("RNG driver for TPM devices");