u-boot/drivers/tpm/tpm2_tis_spi.c

680 lines
15 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0
/*
* Author:
* Miquel Raynal <miquel.raynal@bootlin.com>
*
* Description:
* SPI-level driver for TCG/TIS TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*
* This device driver implements the TPM interface as defined in
* the TCG SPI protocol stack version 2.0.
*
* It is based on the U-Boot driver tpm_tis_infineon_i2c.c.
*/
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <log.h>
#include <spi.h>
#include <tpm-v2.h>
#include <linux/errno.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/unaligned/be_byteshift.h>
#include <asm-generic/gpio.h>
#include "tpm_tis.h"
#include "tpm_internal.h"
DECLARE_GLOBAL_DATA_PTR;
#define TPM_ACCESS(l) (0x0000 | ((l) << 12))
#define TPM_INT_ENABLE(l) (0x0008 | ((l) << 12))
#define TPM_STS(l) (0x0018 | ((l) << 12))
#define TPM_DATA_FIFO(l) (0x0024 | ((l) << 12))
#define TPM_DID_VID(l) (0x0F00 | ((l) << 12))
#define TPM_RID(l) (0x0F04 | ((l) << 12))
#define MAX_SPI_FRAMESIZE 64
/* Number of wait states to wait for */
#define TPM_WAIT_STATES 100
/**
* struct tpm_tis_chip_data - Non-discoverable TPM information
*
* @pcr_count: Number of PCR per bank
* @pcr_select_min: Size in octets of the pcrSelect array
*/
struct tpm_tis_chip_data {
unsigned int pcr_count;
unsigned int pcr_select_min;
unsigned int time_before_first_cmd_ms;
};
/**
* tpm_tis_spi_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_spi_xfer(struct udevice *dev, u32 addr, const u8 *out,
u8 *in, u16 len)
{
struct spi_slave *slave = dev_get_parent_priv(dev);
int transfer_len, ret;
u8 tx_buf[MAX_SPI_FRAMESIZE];
u8 rx_buf[MAX_SPI_FRAMESIZE];
if (in && out) {
log(LOGC_NONE, LOGL_ERR, "%s: can't do full duplex\n",
__func__);
return -EINVAL;
}
ret = spi_claim_bus(slave);
if (ret < 0) {
log(LOGC_NONE, LOGL_ERR, "%s: could not claim bus\n", __func__);
return ret;
}
while (len) {
/* Request */
transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
tx_buf[0] = (in ? BIT(7) : 0) | (transfer_len - 1);
tx_buf[1] = 0xD4;
tx_buf[2] = addr >> 8;
tx_buf[3] = addr;
ret = spi_xfer(slave, 4 * 8, tx_buf, rx_buf, SPI_XFER_BEGIN);
if (ret < 0) {
log(LOGC_NONE, LOGL_ERR,
"%s: spi request transfer failed (err: %d)\n",
__func__, ret);
goto release_bus;
}
/* Wait state */
if (!(rx_buf[3] & 0x1)) {
int i;
for (i = 0; i < TPM_WAIT_STATES; i++) {
ret = spi_xfer(slave, 1 * 8, NULL, rx_buf, 0);
if (ret) {
log(LOGC_NONE, LOGL_ERR,
"%s: wait state failed: %d\n",
__func__, ret);
goto release_bus;
}
if (rx_buf[0] & 0x1)
break;
}
if (i == TPM_WAIT_STATES) {
log(LOGC_NONE, LOGL_ERR,
"%s: timeout on wait state\n", __func__);
ret = -ETIMEDOUT;
goto release_bus;
}
}
/* Read/Write */
if (out) {
memcpy(tx_buf, out, transfer_len);
out += transfer_len;
}
ret = spi_xfer(slave, transfer_len * 8,
out ? tx_buf : NULL,
in ? rx_buf : NULL,
SPI_XFER_END);
if (ret) {
log(LOGC_NONE, LOGL_ERR,
"%s: spi read transfer failed (err: %d)\n",
__func__, ret);
goto release_bus;
}
if (in) {
memcpy(in, rx_buf, transfer_len);
in += transfer_len;
}
len -= transfer_len;
}
release_bus:
/* If an error occurred, release the chip by deasserting the CS */
if (ret < 0)
spi_xfer(slave, 0, NULL, NULL, SPI_XFER_END);
spi_release_bus(slave);
return ret;
}
static int tpm_tis_spi_read(struct udevice *dev, u16 addr, u8 *in, u16 len)
{
return tpm_tis_spi_xfer(dev, addr, NULL, in, len);
}
static int tpm_tis_spi_read32(struct udevice *dev, u32 addr, u32 *result)
{
__le32 result_le;
int ret;
ret = tpm_tis_spi_read(dev, addr, (u8 *)&result_le, sizeof(u32));
if (!ret)
*result = le32_to_cpu(result_le);
return ret;
}
static int tpm_tis_spi_write(struct udevice *dev, u16 addr, const u8 *out,
u16 len)
{
return tpm_tis_spi_xfer(dev, addr, out, NULL, len);
}
static int tpm_tis_spi_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 ret;
ret = tpm_tis_spi_read(dev, TPM_ACCESS(loc), &buf, 1);
if (ret)
return ret;
if ((buf & mask) == mask) {
chip->locality = loc;
return 0;
}
return -ENOENT;
}
static void tpm_tis_spi_release_locality(struct udevice *dev, int loc,
bool force)
{
const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
u8 buf;
if (tpm_tis_spi_read(dev, TPM_ACCESS(loc), &buf, 1) < 0)
return;
if (force || (buf & mask) == mask) {
buf = TPM_ACCESS_ACTIVE_LOCALITY;
tpm_tis_spi_write(dev, TPM_ACCESS(loc), &buf, 1);
}
}
static int tpm_tis_spi_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 ret;
ret = tpm_tis_spi_check_locality(dev, loc);
if (!ret)
return 0;
if (ret != -ENOENT) {
log(LOGC_NONE, LOGL_ERR, "%s: Failed to get locality: %d\n",
__func__, ret);
return ret;
}
ret = tpm_tis_spi_write(dev, TPM_ACCESS(loc), &buf, 1);
if (ret) {
log(LOGC_NONE, LOGL_ERR, "%s: Failed to write to TPM: %d\n",
__func__, ret);
return ret;
}
start = get_timer(0);
stop = chip->timeout_a;
do {
ret = tpm_tis_spi_check_locality(dev, loc);
if (!ret)
return 0;
if (ret != -ENOENT) {
log(LOGC_NONE, LOGL_ERR,
"%s: Failed to get locality: %d\n", __func__, ret);
return ret;
}
mdelay(TPM_TIMEOUT_MS);
} while (get_timer(start) < stop);
log(LOGC_NONE, LOGL_ERR, "%s: Timeout getting locality: %d\n", __func__,
ret);
return ret;
}
static u8 tpm_tis_spi_status(struct udevice *dev, u8 *status)
{
struct tpm_chip *chip = dev_get_priv(dev);
return tpm_tis_spi_read(dev, TPM_STS(chip->locality), status, 1);
}
static int tpm_tis_spi_wait_for_stat(struct udevice *dev, u8 mask,
unsigned long timeout, u8 *status)
{
unsigned long start = get_timer(0);
unsigned long stop = timeout;
int ret;
do {
mdelay(TPM_TIMEOUT_MS);
ret = tpm_tis_spi_status(dev, status);
if (ret)
return ret;
if ((*status & mask) == mask)
return 0;
} while (get_timer(start) < stop);
return -ETIMEDOUT;
}
static int tpm_tis_spi_get_burstcount(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
unsigned long start, stop;
u32 burstcount, ret;
/* wait for burstcount */
start = get_timer(0);
stop = chip->timeout_d;
do {
ret = tpm_tis_spi_read32(dev, TPM_STS(chip->locality),
&burstcount);
if (ret)
return -EBUSY;
burstcount = (burstcount >> 8) & 0xFFFF;
if (burstcount)
return burstcount;
mdelay(TPM_TIMEOUT_MS);
} while (get_timer(start) < stop);
return -EBUSY;
}
static int tpm_tis_spi_cancel(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
u8 data = TPM_STS_COMMAND_READY;
return tpm_tis_spi_write(dev, TPM_STS(chip->locality), &data, 1);
}
static int tpm_tis_spi_recv_data(struct udevice *dev, u8 *buf, size_t count)
{
struct tpm_chip *chip = dev_get_priv(dev);
int size = 0, burstcnt, len, ret;
u8 status;
while (size < count &&
tpm_tis_spi_wait_for_stat(dev,
TPM_STS_DATA_AVAIL | TPM_STS_VALID,
chip->timeout_c, &status) == 0) {
burstcnt = tpm_tis_spi_get_burstcount(dev);
if (burstcnt < 0)
return burstcnt;
len = min_t(int, burstcnt, count - size);
ret = tpm_tis_spi_read(dev, TPM_DATA_FIFO(chip->locality),
buf + size, len);
if (ret < 0)
return ret;
size += len;
}
return size;
}
static int tpm_tis_spi_recv(struct udevice *dev, u8 *buf, size_t count)
{
struct tpm_chip *chip = dev_get_priv(dev);
int size, expected;
if (!chip)
return -ENODEV;
if (count < TPM_HEADER_SIZE) {
size = -EIO;
goto out;
}
size = tpm_tis_spi_recv_data(dev, buf, TPM_HEADER_SIZE);
if (size < TPM_HEADER_SIZE) {
log(LOGC_NONE, LOGL_ERR, "TPM error, unable to read header\n");
goto out;
}
expected = get_unaligned_be32(buf + 2);
if (expected > count) {
size = -EIO;
goto out;
}
size += tpm_tis_spi_recv_data(dev, &buf[TPM_HEADER_SIZE],
expected - TPM_HEADER_SIZE);
if (size < expected) {
log(LOGC_NONE, LOGL_ERR,
"TPM error, unable to read remaining bytes of result\n");
size = -EIO;
goto out;
}
out:
tpm_tis_spi_cancel(dev);
tpm_tis_spi_release_locality(dev, chip->locality, false);
return size;
}
static int tpm_tis_spi_send(struct udevice *dev, const u8 *buf, size_t len)
{
struct tpm_chip *chip = dev_get_priv(dev);
u32 i, size;
u8 status;
int burstcnt, ret;
u8 data;
if (!chip)
return -ENODEV;
if (len > TPM_DEV_BUFSIZE)
return -E2BIG; /* Command is too long for our tpm, sorry */
ret = tpm_tis_spi_request_locality(dev, 0);
if (ret < 0)
return -EBUSY;
/*
* Check if the TPM is ready. If not, if not, cancel the pending command
* and poll on the status to be finally ready.
*/
ret = tpm_tis_spi_status(dev, &status);
if (ret)
return ret;
if (!(status & TPM_STS_COMMAND_READY)) {
/* Force the transition, usually this will be done at startup */
ret = tpm_tis_spi_cancel(dev);
if (ret) {
log(LOGC_NONE, LOGL_ERR,
"%s: Could not cancel previous operation\n",
__func__);
goto out_err;
}
ret = tpm_tis_spi_wait_for_stat(dev, TPM_STS_COMMAND_READY,
chip->timeout_b, &status);
if (ret < 0 || !(status & TPM_STS_COMMAND_READY)) {
log(LOGC_NONE, LOGL_ERR,
"status %d after wait for stat returned %d\n",
status, ret);
goto out_err;
}
}
for (i = 0; i < len - 1;) {
burstcnt = tpm_tis_spi_get_burstcount(dev);
if (burstcnt < 0)
return burstcnt;
size = min_t(int, len - i - 1, burstcnt);
ret = tpm_tis_spi_write(dev, TPM_DATA_FIFO(chip->locality),
buf + i, size);
if (ret < 0)
goto out_err;
i += size;
}
ret = tpm_tis_spi_status(dev, &status);
if (ret)
goto out_err;
if ((status & TPM_STS_DATA_EXPECT) == 0) {
ret = -EIO;
goto out_err;
}
ret = tpm_tis_spi_write(dev, TPM_DATA_FIFO(chip->locality),
buf + len - 1, 1);
if (ret)
goto out_err;
ret = tpm_tis_spi_status(dev, &status);
if (ret)
goto out_err;
if ((status & TPM_STS_DATA_EXPECT) != 0) {
ret = -EIO;
goto out_err;
}
data = TPM_STS_GO;
ret = tpm_tis_spi_write(dev, TPM_STS(chip->locality), &data, 1);
if (ret)
goto out_err;
return len;
out_err:
tpm_tis_spi_cancel(dev);
tpm_tis_spi_release_locality(dev, chip->locality, false);
return ret;
}
static int tpm_tis_spi_cleanup(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
tpm_tis_spi_cancel(dev);
/*
* The TPM needs some time to clean up here,
* so we sleep rather than keeping the bus busy
*/
mdelay(2);
tpm_tis_spi_release_locality(dev, chip->locality, false);
return 0;
}
static int tpm_tis_spi_open(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
if (chip->is_open)
return -EBUSY;
chip->is_open = 1;
return 0;
}
static int tpm_tis_spi_close(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
if (chip->is_open) {
tpm_tis_spi_release_locality(dev, chip->locality, true);
chip->is_open = 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 < 80)
return -ENOSPC;
return snprintf(buf, size,
"%s v2.0: VendorID 0x%04x, DeviceID 0x%04x, RevisionID 0x%02x [%s]",
dev->name, chip->vend_dev & 0xFFFF,
chip->vend_dev >> 16, chip->rid,
(chip->is_open ? "open" : "closed"));
}
static int tpm_tis_wait_init(struct udevice *dev, int loc)
{
struct tpm_chip *chip = dev_get_priv(dev);
unsigned long start, stop;
u8 status;
int ret;
start = get_timer(0);
stop = chip->timeout_b;
do {
mdelay(TPM_TIMEOUT_MS);
ret = tpm_tis_spi_read(dev, TPM_ACCESS(loc), &status, 1);
if (ret)
break;
if (status & TPM_ACCESS_VALID)
return 0;
} while (get_timer(start) < stop);
return -EIO;
}
static int tpm_tis_spi_probe(struct udevice *dev)
{
struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(dev);
struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
struct tpm_chip *chip = dev_get_priv(dev);
int ret;
if (IS_ENABLED(CONFIG_DM_GPIO)) {
struct gpio_desc reset_gpio;
ret = gpio_request_by_name(dev, "gpio-reset", 0,
&reset_gpio, GPIOD_IS_OUT);
if (ret) {
log(LOGC_NONE, LOGL_NOTICE, "%s: missing reset GPIO\n",
__func__);
} else {
dm_gpio_set_value(&reset_gpio, 0);
mdelay(1);
dm_gpio_set_value(&reset_gpio, 1);
}
}
/* Ensure a minimum amount of time elapsed since reset of the TPM */
mdelay(drv_data->time_before_first_cmd_ms);
chip->locality = 0;
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;
priv->pcr_count = drv_data->pcr_count;
priv->pcr_select_min = drv_data->pcr_select_min;
ret = tpm_tis_wait_init(dev, chip->locality);
if (ret) {
log(LOGC_DM, LOGL_ERR, "%s: no device found\n", __func__);
return ret;
}
ret = tpm_tis_spi_request_locality(dev, chip->locality);
if (ret) {
log(LOGC_NONE, LOGL_ERR, "%s: could not request locality %d\n",
__func__, chip->locality);
return ret;
}
ret = tpm_tis_spi_read32(dev, TPM_DID_VID(chip->locality),
&chip->vend_dev);
if (ret) {
log(LOGC_NONE, LOGL_ERR,
"%s: could not retrieve VendorID/DeviceID\n", __func__);
return ret;
}
ret = tpm_tis_spi_read(dev, TPM_RID(chip->locality), &chip->rid, 1);
if (ret) {
log(LOGC_NONE, LOGL_ERR, "%s: could not retrieve RevisionID\n",
__func__);
return ret;
}
log(LOGC_NONE, LOGL_ERR,
"SPI TPMv2.0 found (vid:%04x, did:%04x, rid:%02x)\n",
chip->vend_dev & 0xFFFF, chip->vend_dev >> 16, chip->rid);
return 0;
}
static int tpm_tis_spi_remove(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
tpm_tis_spi_release_locality(dev, chip->locality, true);
return 0;
}
static const struct tpm_ops tpm_tis_spi_ops = {
.open = tpm_tis_spi_open,
.close = tpm_tis_spi_close,
.get_desc = tpm_tis_get_desc,
.send = tpm_tis_spi_send,
.recv = tpm_tis_spi_recv,
.cleanup = tpm_tis_spi_cleanup,
};
static const struct tpm_tis_chip_data tpm_tis_std_chip_data = {
.pcr_count = 24,
.pcr_select_min = 3,
.time_before_first_cmd_ms = 30,
};
static const struct udevice_id tpm_tis_spi_ids[] = {
{
.compatible = "tis,tpm2-spi",
.data = (ulong)&tpm_tis_std_chip_data,
},
{ }
};
U_BOOT_DRIVER(tpm_tis_spi) = {
.name = "tpm_tis_spi",
.id = UCLASS_TPM,
.of_match = tpm_tis_spi_ids,
.ops = &tpm_tis_spi_ops,
.probe = tpm_tis_spi_probe,
.remove = tpm_tis_spi_remove,
.priv_auto_alloc_size = sizeof(struct tpm_chip),
};