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/*
* Copyright (C) 2011 Infineon Technologies
*
* Authors:
* Peter Huewe <huewe.external@infineon.com>
*
* Description:
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*
* This device driver implements the TPM interface as defined in
* the TCG TPM Interface Spec version 1.2, revision 1.0 and the
* Infineon I2C Protocol Stack Specification v0.20.
*
* It is based on the Linux kernel driver tpm.c from Leendert van
* Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
*
* Version: 2.1.1
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <i2c.h>
#include <tis.h>
#include <tpm.h>
#include <asm-generic/errno.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/unaligned/be_byteshift.h>
#include "tpm_tis_i2c.h"
#include "tpm_internal.h"
DECLARE_GLOBAL_DATA_PTR;
static const char * const chip_name[] = {
[SLB9635] = "slb9635tt",
[SLB9645] = "slb9645tt",
[UNKNOWN] = "unknown/fallback to slb9635",
};
/*
* tpm_tis_i2c_read() - read from TPM register
* @addr: register address to read from
* @buffer: provided by caller
* @len: number of bytes to read
*
* Read len bytes from TPM register and put them into
* buffer (little-endian format, i.e. first byte is put into buffer[0]).
*
* NOTE: TPM is big-endian for multi-byte values. Multi-byte
* values have to be swapped.
*
* Return -EIO on error, 0 on success.
*/
static int tpm_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer,
size_t len)
{
struct tpm_chip *chip = dev_get_priv(dev);
int rc;
int count;
uint32_t addrbuf = addr;
if ((chip->chip_type == SLB9635) || (chip->chip_type == UNKNOWN)) {
/* slb9635 protocol should work in both cases */
for (count = 0; count < MAX_COUNT; count++) {
rc = dm_i2c_write(dev, 0, (uchar *)&addrbuf, 1);
if (rc == 0)
break; /* Success, break to skip sleep */
udelay(SLEEP_DURATION_US);
}
if (rc)
return rc;
/* After the TPM has successfully received the register address
* it needs some time, thus we're sleeping here again, before
* retrieving the data
*/
for (count = 0; count < MAX_COUNT; count++) {
udelay(SLEEP_DURATION_US);
rc = dm_i2c_read(dev, 0, buffer, len);
if (rc == 0)
break; /* success, break to skip sleep */
}
} else {
/*
* Use a combined read for newer chips.
* Unfortunately the smbus functions are not suitable due to
* the 32 byte limit of the smbus.
* Retries should usually not be needed, but are kept just to
* be safe on the safe side.
*/
for (count = 0; count < MAX_COUNT; count++) {
rc = dm_i2c_read(dev, addr, buffer, len);
if (rc == 0)
break; /* break here to skip sleep */
udelay(SLEEP_DURATION_US);
}
}
/* Take care of 'guard time' */
udelay(SLEEP_DURATION_US);
if (rc)
return rc;
return 0;
}
static int tpm_tis_i2c_write_generic(struct udevice *dev, u8 addr,
const u8 *buffer, size_t len,
unsigned int sleep_time_us, u8 max_count)
{
struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
struct tpm_chip *chip = dev_get_priv(dev);
int rc = 0;
int count;
if (chip->chip_type == SLB9635) {
/* Prepare send buffer to include the address */
priv->buf[0] = addr;
memcpy(&(priv->buf[1]), buffer, len);
buffer = priv->buf;
len++;
addr = 0;
}
for (count = 0; count < max_count; count++) {
rc = dm_i2c_write(dev, addr, buffer, len);
if (rc == 0)
break; /* Success, break to skip sleep */
udelay(sleep_time_us);
}
/* take care of 'guard time' */
udelay(sleep_time_us);
if (rc)
return rc;
return 0;
}
/*
* tpm_tis_i2c_write() - write to TPM register
* @addr: register address to write to
* @buffer: containing data to be written
* @len: number of bytes to write
*
* Write len bytes from provided buffer to TPM register (little
* endian format, i.e. buffer[0] is written as first byte).
*
* NOTE: TPM is big-endian for multi-byte values. Multi-byte
* values have to be swapped.
*
* NOTE: use this function instead of the tpm_tis_i2c_write_generic function.
*
* Return -EIO on error, 0 on success
*/
static int tpm_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer,
size_t len)
{
return tpm_tis_i2c_write_generic(dev, addr, buffer, len,
SLEEP_DURATION_US, MAX_COUNT);
}
/*
* This function is needed especially for the cleanup situation after
* sending TPM_READY
*/
static int tpm_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer,
size_t len)
{
return tpm_tis_i2c_write_generic(dev, addr, buffer, len,
SLEEP_DURATION_LONG_US,
MAX_COUNT_LONG);
}
static int tpm_tis_i2c_check_locality(struct udevice *dev, int loc)
{
const u8 mask = TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID;
struct tpm_chip *chip = dev_get_priv(dev);
u8 buf;
int rc;
rc = tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1);
if (rc < 0)
return rc;
if ((buf & mask) == mask) {
chip->locality = loc;
return loc;
}
return -ENOENT;
}
static void tpm_tis_i2c_release_locality(struct udevice *dev, int loc,
int force)
{
const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
u8 buf;
if (tpm_tis_i2c_read(dev, TPM_ACCESS(loc), &buf, 1) < 0)
return;
if (force || (buf & mask) == mask) {
buf = TPM_ACCESS_ACTIVE_LOCALITY;
tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1);
}
}
static int tpm_tis_i2c_request_locality(struct udevice *dev, int loc)
{
struct tpm_chip *chip = dev_get_priv(dev);
unsigned long start, stop;
u8 buf = TPM_ACCESS_REQUEST_USE;
int rc;
rc = tpm_tis_i2c_check_locality(dev, loc);
if (rc >= 0) {
debug("%s: Already have locality\n", __func__);
return loc; /* We already have the locality */
} else if (rc != -ENOENT) {
debug("%s: Failed to get locality: %d\n", __func__, rc);
return rc;
}
rc = tpm_tis_i2c_write(dev, TPM_ACCESS(loc), &buf, 1);
if (rc) {
debug("%s: Failed to write to TPM: %d\n", __func__, rc);
return rc;
}
/* Wait for burstcount */
start = get_timer(0);
stop = chip->timeout_a;
do {
rc = tpm_tis_i2c_check_locality(dev, loc);
if (rc >= 0) {
debug("%s: Have locality\n", __func__);
return loc;
} else if (rc != -ENOENT) {
debug("%s: Failed to get locality: %d\n", __func__, rc);
return rc;
}
mdelay(TPM_TIMEOUT_MS);
} while (get_timer(start) < stop);
debug("%s: Timeout getting locality: %d\n", __func__, rc);
return rc;
}
static u8 tpm_tis_i2c_status(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
/* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
u8 buf;
if (tpm_tis_i2c_read(dev, TPM_STS(chip->locality), &buf, 1) < 0)
return 0;
else
return buf;
}
static int tpm_tis_i2c_ready(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
int rc;
/* This causes the current command to be aborted */
u8 buf = TPM_STS_COMMAND_READY;
debug("%s\n", __func__);
rc = tpm_tis_i2c_write_long(dev, TPM_STS(chip->locality), &buf, 1);
if (rc)
debug("%s: rc=%d\n", __func__, rc);
return rc;
}
static ssize_t tpm_tis_i2c_get_burstcount(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
unsigned long start, stop;
ssize_t burstcnt;
u8 addr, buf[3];
/* Wait for burstcount */
/* XXX: Which timeout value? Spec has 2 answers (c & d) */
start = get_timer(0);
stop = chip->timeout_d;
do {
/* Note: STS is little endian */
addr = TPM_STS(chip->locality) + 1;
if (tpm_tis_i2c_read(dev, addr, buf, 3) < 0)
burstcnt = 0;
else
burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
if (burstcnt)
return burstcnt;
mdelay(TPM_TIMEOUT_MS);
} while (get_timer(start) < stop);
return -EBUSY;
}
static int tpm_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask,
unsigned long timeout, int *status)
{
unsigned long start, stop;
/* Check current status */
*status = tpm_tis_i2c_status(dev);
if ((*status & mask) == mask)
return 0;
start = get_timer(0);
stop = timeout;
do {
mdelay(TPM_TIMEOUT_MS);
*status = tpm_tis_i2c_status(dev);
if ((*status & mask) == mask)
return 0;
} while (get_timer(start) < stop);
return -ETIMEDOUT;
}
static int tpm_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
{
struct tpm_chip *chip = dev_get_priv(dev);
size_t size = 0;
ssize_t burstcnt;
int rc;
while (size < count) {
burstcnt = tpm_tis_i2c_get_burstcount(dev);
/* burstcount < 0 -> tpm is busy */
if (burstcnt < 0)
return burstcnt;
/* Limit received data to max left */
if (burstcnt > (count - size))
burstcnt = count - size;
rc = tpm_tis_i2c_read(dev, TPM_DATA_FIFO(chip->locality),
&(buf[size]), burstcnt);
if (rc == 0)
size += burstcnt;
}
return size;
}
static int tpm_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
{
struct tpm_chip *chip = dev_get_priv(dev);
int size = 0;
int expected, status;
int rc;
status = tpm_tis_i2c_status(dev);
if (status == TPM_STS_COMMAND_READY)
return -EINTR;
if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) !=
(TPM_STS_DATA_AVAIL | TPM_STS_VALID))
return -EAGAIN;
debug("...got it;\n");
/* Read first 10 bytes, including tag, paramsize, and result */
size = tpm_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
if (size < TPM_HEADER_SIZE) {
debug("Unable to read header\n");
return size < 0 ? size : -EIO;
}
expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
if ((size_t)expected > count) {
debug("Error size=%x, expected=%x, count=%x\n", size, expected,
count);
return -ENOSPC;
}
size += tpm_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
expected - TPM_HEADER_SIZE);
if (size < expected) {
debug("Unable to read remainder of result\n");
return -ETIMEDOUT;
}
rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c,
&status);
if (rc)
return rc;
if (status & TPM_STS_DATA_AVAIL) { /* Retry? */
debug("Error left over data\n");
return -EIO;
}
return size;
}
static int tpm_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
{
struct tpm_chip *chip = dev_get_priv(dev);
int rc, status;
size_t burstcnt;
size_t count = 0;
int retry = 0;
u8 sts = TPM_STS_GO;
debug("%s: len=%d\n", __func__, len);
if (len > TPM_DEV_BUFSIZE)
return -E2BIG; /* Command is too long for our tpm, sorry */
if (tpm_tis_i2c_request_locality(dev, 0) < 0)
return -EBUSY;
status = tpm_tis_i2c_status(dev);
if ((status & TPM_STS_COMMAND_READY) == 0) {
rc = tpm_tis_i2c_ready(dev);
if (rc)
return rc;
rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
chip->timeout_b, &status);
if (rc)
return rc;
}
burstcnt = tpm_tis_i2c_get_burstcount(dev);
/* burstcount < 0 -> tpm is busy */
if (burstcnt < 0)
return burstcnt;
while (count < len) {
udelay(300);
if (burstcnt > len - count)
burstcnt = len - count;
#ifdef CONFIG_TPM_TIS_I2C_BURST_LIMITATION
if (retry && burstcnt > CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN)
burstcnt = CONFIG_TPM_TIS_I2C_BURST_LIMITATION_LEN;
#endif /* CONFIG_TPM_TIS_I2C_BURST_LIMITATION */
rc = tpm_tis_i2c_write(dev, TPM_DATA_FIFO(chip->locality),
&(buf[count]), burstcnt);
if (rc == 0)
count += burstcnt;
else {
debug("%s: error\n", __func__);
if (retry++ > 10)
return -EIO;
rc = tpm_tis_i2c_wait_for_stat(dev, TPM_STS_VALID,
chip->timeout_c,
&status);
if (rc)
return rc;
if ((status & TPM_STS_DATA_EXPECT) == 0)
return -EIO;
}
}
/* Go and do it */
rc = tpm_tis_i2c_write(dev, TPM_STS(chip->locality), &sts, 1);
if (rc < 0)
return rc;
debug("%s: done, rc=%d\n", __func__, rc);
return len;
}
static int tpm_tis_i2c_cleanup(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
tpm_tis_i2c_ready(dev);
/*
* The TPM needs some time to clean up here,
* so we sleep rather than keeping the bus busy
*/
mdelay(2);
tpm_tis_i2c_release_locality(dev, chip->locality, 0);
return 0;
}
static int tpm_tis_i2c_init(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
u32 vendor;
u32 expected_did_vid;
int rc;
chip->is_open = 1;
/* Default timeouts - these could move to the device tree */
chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
chip->timeout_b = TIS_LONG_TIMEOUT_MS;
chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
rc = tpm_tis_i2c_request_locality(dev, 0);
if (rc < 0)
return rc;
/* Read four bytes from DID_VID register */
if (tpm_tis_i2c_read(dev, TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
tpm_tis_i2c_release_locality(dev, 0, 1);
return -EIO;
}
if (chip->chip_type == SLB9635) {
vendor = be32_to_cpu(vendor);
expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
} else {
/* device id and byte order has changed for newer i2c tpms */
expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
}
if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) {
error("Vendor id did not match! ID was %08x\n", vendor);
return -ENODEV;
}
chip->vend_dev = vendor;
debug("1.2 TPM (chip type %s device-id 0x%X)\n",
chip_name[chip->chip_type], vendor >> 16);
/*
* A timeout query to TPM can be placed here.
* Standard timeout values are used so far
*/
return 0;
}
static int tpm_tis_i2c_open(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
int rc;
debug("%s: start\n", __func__);
if (chip->is_open)
return -EBUSY;
rc = tpm_tis_i2c_init(dev);
if (rc < 0)
chip->is_open = 0;
return rc;
}
static int tpm_tis_i2c_close(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
if (chip->is_open) {
tpm_tis_i2c_release_locality(dev, chip->locality, 1);
chip->is_open = 0;
chip->vend_dev = 0;
}
return 0;
}
static int tpm_tis_get_desc(struct udevice *dev, char *buf, int size)
{
struct tpm_chip *chip = dev_get_priv(dev);
if (size < 50)
return -ENOSPC;
return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
chip->is_open ? "open" : "closed",
chip_name[chip->chip_type],
chip->vend_dev >> 16);
}
static int tpm_tis_i2c_probe(struct udevice *dev)
{
struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
struct tpm_chip *chip = dev_get_priv(dev);
chip->chip_type = dev_get_driver_data(dev);
/* TODO: These need to be checked and tuned */
uc_priv->duration_ms[TPM_SHORT] = TIS_SHORT_TIMEOUT_MS;
uc_priv->duration_ms[TPM_MEDIUM] = TIS_LONG_TIMEOUT_MS;
uc_priv->duration_ms[TPM_LONG] = TIS_LONG_TIMEOUT_MS;
uc_priv->retry_time_ms = TPM_TIMEOUT_MS;
return 0;
}
static const struct tpm_ops tpm_tis_i2c_ops = {
.open = tpm_tis_i2c_open,
.close = tpm_tis_i2c_close,
.get_desc = tpm_tis_get_desc,
.send = tpm_tis_i2c_send,
.recv = tpm_tis_i2c_recv,
.cleanup = tpm_tis_i2c_cleanup,
};
static const struct udevice_id tpm_tis_i2c_ids[] = {
{ .compatible = "infineon,slb9635tt", .data = SLB9635 },
{ .compatible = "infineon,slb9645tt", .data = SLB9645 },
{ }
};
U_BOOT_DRIVER(tpm_tis_i2c) = {
.name = "tpm_tis_i2c",
.id = UCLASS_TPM,
.of_match = tpm_tis_i2c_ids,
.ops = &tpm_tis_i2c_ops,
.probe = tpm_tis_i2c_probe,
.priv_auto_alloc_size = sizeof(struct tpm_chip),
};