coreboot-kgpe-d16/src/drivers/i2c/tpm/tis_i2c.c

104 lines
2.0 KiB
C

/*
* Copyright 2013 Google Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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; either version 2 of
* the License, or (at your option) any later version.
*
* 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 <stdint.h>
#include <string.h>
#include <device/i2c.h>
#include "tis.h"
#include "tpm.h"
static unsigned bus = 0;
static int opened;
void tis_set_i2c_bus(unsigned _bus)
{
bus = _bus;
}
int tis_open(void)
{
opened = 1;
if (tpm_open(bus, CONFIG_DRIVER_TPM_I2C_ADDR)) {
opened = 0;
return -1;
}
return 0;
}
int tis_close(void)
{
opened = 0;
tpm_close();
return 0;
}
int tis_init(void)
{
int chip = CONFIG_DRIVER_TPM_I2C_ADDR;
/*
* Probe TPM twice; the first probing might fail because TPM is asleep,
* and the probing can wake up TPM.
*/
uint8_t tmp;
if (!bus)
return -1;
if (i2c_read(bus, chip, 0, 0, &tmp, sizeof(tmp)) &&
i2c_read(bus, chip, 0, 0, &tmp, sizeof(tmp)))
return -1;
return 0;
}
int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
uint8_t *recvbuf, size_t *rbuf_len)
{
uint8_t buf[TPM_BUFSIZE];
if (!opened && tis_open())
return -1;
if (sizeof(buf) < sbuf_size)
return -1;
memcpy(buf, sendbuf, sbuf_size);
int len = tpm_transmit(buf, sbuf_size);
if (len < 10) {
*rbuf_len = 0;
return -1;
}
if (len > *rbuf_len) {
*rbuf_len = len;
return -1;
}
memcpy(recvbuf, buf, len);
*rbuf_len = len;
return 0;
}