u-boot/drivers/tpm/tpm_tis_st33zp24_spi.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

673 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* STMicroelectronics TPM ST33ZP24 SPI UBOOT driver
*
* Copyright (C) 2016, STMicroelectronics - All Rights Reserved
* Author(s): Christophe Ricard <christophe-h.ricard@st.com> for STMicroelectronics.
*
* Description: Device driver for ST33ZP24 SPI TPM TCG.
*
* This device driver implements the TPM interface as defined in
* the TCG TPM Interface Spec version 1.21, revision 1.0 and the
* STMicroelectronics Protocol Stack Specification version 1.2.0.
*/
#include <common.h>
#include <dm.h>
#include <fdtdec.h>
#include <spi.h>
#include <tpm.h>
#include <errno.h>
#include <linux/types.h>
#include <asm/unaligned.h>
#include <linux/compat.h>
#include "tpm_tis.h"
#include "tpm_internal.h"
#define TPM_ACCESS 0x0
#define TPM_STS 0x18
#define TPM_DATA_FIFO 0x24
#define LOCALITY0 0
#define TPM_DATA_FIFO 0x24
#define TPM_INTF_CAPABILITY 0x14
#define TPM_DUMMY_BYTE 0x00
#define TPM_WRITE_DIRECTION 0x80
#define MAX_SPI_LATENCY 15
#define LOCALITY0 0
#define ST33ZP24_OK 0x5A
#define ST33ZP24_UNDEFINED_ERR 0x80
#define ST33ZP24_BADLOCALITY 0x81
#define ST33ZP24_TISREGISTER_UKNOWN 0x82
#define ST33ZP24_LOCALITY_NOT_ACTIVATED 0x83
#define ST33ZP24_HASH_END_BEFORE_HASH_START 0x84
#define ST33ZP24_BAD_COMMAND_ORDER 0x85
#define ST33ZP24_INCORECT_RECEIVED_LENGTH 0x86
#define ST33ZP24_TPM_FIFO_OVERFLOW 0x89
#define ST33ZP24_UNEXPECTED_READ_FIFO 0x8A
#define ST33ZP24_UNEXPECTED_WRITE_FIFO 0x8B
#define ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END 0x90
#define ST33ZP24_DUMMY_BYTES 0x00
/*
* TPM command can be up to 2048 byte, A TPM response can be up to
* 1024 byte.
* Between command and response, there are latency byte (up to 15
* usually on st33zp24 2 are enough).
*
* Overall when sending a command and expecting an answer we need if
* worst case:
* 2048 (for the TPM command) + 1024 (for the TPM answer). We need
* some latency byte before the answer is available (max 15).
* We have 2048 + 1024 + 15.
*/
#define ST33ZP24_SPI_BUFFER_SIZE (TPM_BUFSIZE + (TPM_BUFSIZE / 2) +\
MAX_SPI_LATENCY)
struct st33zp24_spi_phy {
int latency;
u8 tx_buf[ST33ZP24_SPI_BUFFER_SIZE];
u8 rx_buf[ST33ZP24_SPI_BUFFER_SIZE];
};
static int st33zp24_spi_status_to_errno(u8 code)
{
switch (code) {
case ST33ZP24_OK:
return 0;
case ST33ZP24_UNDEFINED_ERR:
case ST33ZP24_BADLOCALITY:
case ST33ZP24_TISREGISTER_UKNOWN:
case ST33ZP24_LOCALITY_NOT_ACTIVATED:
case ST33ZP24_HASH_END_BEFORE_HASH_START:
case ST33ZP24_BAD_COMMAND_ORDER:
case ST33ZP24_UNEXPECTED_READ_FIFO:
case ST33ZP24_UNEXPECTED_WRITE_FIFO:
case ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END:
return -EPROTO;
case ST33ZP24_INCORECT_RECEIVED_LENGTH:
case ST33ZP24_TPM_FIFO_OVERFLOW:
return -EMSGSIZE;
case ST33ZP24_DUMMY_BYTES:
return -ENOSYS;
}
return code;
}
/*
* st33zp24_spi_send
* Send byte to TPM register according to the ST33ZP24 SPI protocol.
* @param: tpm, the chip description
* @param: tpm_register, the tpm tis register where the data should be written
* @param: tpm_data, the tpm_data to write inside the tpm_register
* @param: tpm_size, The length of the data
* @return: should be zero if success else a negative error code.
*/
static int st33zp24_spi_write(struct udevice *dev, u8 tpm_register,
const u8 *tpm_data, size_t tpm_size)
{
int total_length = 0, ret;
struct spi_slave *slave = dev_get_parent_priv(dev);
struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
u8 *tx_buf = (u8 *)phy->tx_buf;
u8 *rx_buf = phy->rx_buf;
tx_buf[total_length++] = TPM_WRITE_DIRECTION | LOCALITY0;
tx_buf[total_length++] = tpm_register;
if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) {
tx_buf[total_length++] = tpm_size >> 8;
tx_buf[total_length++] = tpm_size;
}
memcpy(tx_buf + total_length, tpm_data, tpm_size);
total_length += tpm_size;
memset(tx_buf + total_length, TPM_DUMMY_BYTE, phy->latency);
total_length += phy->latency;
ret = spi_claim_bus(slave);
if (ret < 0)
return ret;
ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf,
SPI_XFER_BEGIN | SPI_XFER_END);
if (ret < 0)
return ret;
spi_release_bus(slave);
if (ret == 0)
ret = rx_buf[total_length - 1];
return st33zp24_spi_status_to_errno(ret);
}
/*
* spi_st33zp24_spi_read8_reg
* Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
* @param: tpm, the chip description
* @param: tpm_loc, the locality to read register from
* @param: tpm_register, the tpm tis register where the data should be read
* @param: tpm_data, the TPM response
* @param: tpm_size, tpm TPM response size to read.
* @return: should be zero if success else a negative error code.
*/
static u8 st33zp24_spi_read8_reg(struct udevice *dev, u8 tpm_register,
u8 *tpm_data, size_t tpm_size)
{
int total_length = 0, ret;
struct spi_slave *slave = dev_get_parent_priv(dev);
struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
u8 *tx_buf = (u8 *)phy->tx_buf;
u8 *rx_buf = phy->rx_buf;
/* Pre-Header */
tx_buf[total_length++] = LOCALITY0;
tx_buf[total_length++] = tpm_register;
memset(&tx_buf[total_length], TPM_DUMMY_BYTE,
phy->latency + tpm_size);
total_length += phy->latency + tpm_size;
ret = spi_claim_bus(slave);
if (ret < 0)
return 0;
ret = spi_xfer(slave, total_length * 8, tx_buf, rx_buf,
SPI_XFER_BEGIN | SPI_XFER_END);
if (ret < 0)
return 0;
spi_release_bus(slave);
if (tpm_size > 0 && ret == 0) {
ret = rx_buf[total_length - tpm_size - 1];
memcpy(tpm_data, rx_buf + total_length - tpm_size, tpm_size);
}
return ret;
}
/*
* st33zp24_spi_recv
* Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
* @param: phy_id, the phy description
* @param: tpm_register, the tpm tis register where the data should be read
* @param: tpm_data, the TPM response
* @param: tpm_size, tpm TPM response size to read.
* @return: number of byte read successfully: should be one if success.
*/
static int st33zp24_spi_read(struct udevice *dev, u8 tpm_register,
u8 *tpm_data, size_t tpm_size)
{
int ret;
ret = st33zp24_spi_read8_reg(dev, tpm_register, tpm_data, tpm_size);
if (!st33zp24_spi_status_to_errno(ret))
return tpm_size;
return ret;
}
static int st33zp24_spi_evaluate_latency(struct udevice *dev)
{
int latency = 1, status = 0;
u8 data = 0;
struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
while (!status && latency < MAX_SPI_LATENCY) {
phy->latency = latency;
status = st33zp24_spi_read8_reg(dev, TPM_INTF_CAPABILITY,
&data, 1);
latency++;
}
if (status < 0)
return status;
if (latency == MAX_SPI_LATENCY)
return -ENODEV;
return latency - 1;
}
/*
* st33zp24_spi_release_locality release the active locality
* @param: chip, the tpm chip description.
*/
static void st33zp24_spi_release_locality(struct udevice *dev)
{
u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
st33zp24_spi_write(dev, TPM_ACCESS, &data, 1);
}
/*
* st33zp24_spi_check_locality if the locality is active
* @param: chip, the tpm chip description
* @return: the active locality or -EACCES.
*/
static int st33zp24_spi_check_locality(struct udevice *dev)
{
u8 data;
u8 status;
struct tpm_chip *chip = dev_get_priv(dev);
status = st33zp24_spi_read(dev, TPM_ACCESS, &data, 1);
if (status && (data &
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
return chip->locality;
return -EACCES;
}
/*
* st33zp24_spi_request_locality request the TPM locality
* @param: chip, the chip description
* @return: the active locality or negative value.
*/
static int st33zp24_spi_request_locality(struct udevice *dev)
{
unsigned long start, stop;
long ret;
u8 data;
struct tpm_chip *chip = dev_get_priv(dev);
if (st33zp24_spi_check_locality(dev) == chip->locality)
return chip->locality;
data = TPM_ACCESS_REQUEST_USE;
ret = st33zp24_spi_write(dev, TPM_ACCESS, &data, 1);
if (ret < 0)
return ret;
/* wait for locality activated */
start = get_timer(0);
stop = chip->timeout_a;
do {
if (st33zp24_spi_check_locality(dev) >= 0)
return chip->locality;
udelay(TPM_TIMEOUT_MS * 1000);
} while (get_timer(start) < stop);
return -EACCES;
}
/*
* st33zp24_spi_status return the TPM_STS register
* @param: chip, the tpm chip description
* @return: the TPM_STS register value.
*/
static u8 st33zp24_spi_status(struct udevice *dev)
{
u8 data;
st33zp24_spi_read(dev, TPM_STS, &data, 1);
return data;
}
/*
* st33zp24_spi_get_burstcount return the burstcount address 0x19 0x1A
* @param: chip, the chip description
* return: the burstcount or -TPM_DRIVER_ERR in case of error.
*/
static int st33zp24_spi_get_burstcount(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
unsigned long start, stop;
int burstcnt, status;
u8 tpm_reg, temp;
/* wait for burstcount */
start = get_timer(0);
stop = chip->timeout_d;
do {
tpm_reg = TPM_STS + 1;
status = st33zp24_spi_read(dev, tpm_reg, &temp, 1);
if (status < 0)
return -EBUSY;
tpm_reg = TPM_STS + 2;
burstcnt = temp;
status = st33zp24_spi_read(dev, tpm_reg, &temp, 1);
if (status < 0)
return -EBUSY;
burstcnt |= temp << 8;
if (burstcnt)
return burstcnt;
udelay(TIS_SHORT_TIMEOUT_MS * 1000);
} while (get_timer(start) < stop);
return -EBUSY;
}
/*
* st33zp24_spi_cancel, cancel the current command execution or
* set STS to COMMAND READY.
* @param: chip, tpm_chip description.
*/
static void st33zp24_spi_cancel(struct udevice *dev)
{
u8 data;
data = TPM_STS_COMMAND_READY;
st33zp24_spi_write(dev, TPM_STS, &data, 1);
}
/*
* st33zp24_spi_wait_for_stat wait for a TPM_STS value
* @param: chip, the tpm chip description
* @param: mask, the value mask to wait
* @param: timeout, the timeout
* @param: status,
* @return: the tpm status, 0 if success, -ETIME if timeout is reached.
*/
static int st33zp24_spi_wait_for_stat(struct udevice *dev, u8 mask,
unsigned long timeout, int *status)
{
unsigned long start, stop;
/* Check current status */
*status = st33zp24_spi_status(dev);
if ((*status & mask) == mask)
return 0;
start = get_timer(0);
stop = timeout;
do {
udelay(TPM_TIMEOUT_MS * 1000);
*status = st33zp24_spi_status(dev);
if ((*status & mask) == mask)
return 0;
} while (get_timer(start) < stop);
return -ETIME;
}
/*
* st33zp24_spi_recv_data receive data
* @param: chip, the tpm chip description
* @param: buf, the buffer where the data are received
* @param: count, the number of data to receive
* @return: the number of bytes read from TPM FIFO.
*/
static int st33zp24_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, status;
while (size < count &&
st33zp24_spi_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
chip->timeout_c, &status) == 0) {
burstcnt = st33zp24_spi_get_burstcount(dev);
if (burstcnt < 0)
return burstcnt;
len = min_t(int, burstcnt, count - size);
ret = st33zp24_spi_read(dev, TPM_DATA_FIFO, buf + size, len);
if (ret < 0)
return ret;
size += len;
}
return size;
}
/*
* st33zp24_spi_recv received TPM response through TPM phy.
* @param: chip, tpm_chip description.
* @param: buf, the buffer to store data.
* @param: count, the number of bytes that can received (sizeof buf).
* @return: Returns zero in case of success else -EIO.
*/
static int st33zp24_spi_recv(struct udevice *dev, u8 *buf, size_t count)
{
struct tpm_chip *chip = dev_get_priv(dev);
int size;
unsigned int expected;
if (!chip)
return -ENODEV;
if (count < TPM_HEADER_SIZE) {
size = -EIO;
goto out;
}
size = st33zp24_spi_recv_data(dev, buf, TPM_HEADER_SIZE);
if (size < TPM_HEADER_SIZE) {
debug("TPM error, unable to read header\n");
goto out;
}
expected = get_unaligned_be32(buf + 2);
if (expected > count || expected < TPM_HEADER_SIZE) {
size = -EIO;
goto out;
}
size += st33zp24_spi_recv_data(dev, &buf[TPM_HEADER_SIZE],
expected - TPM_HEADER_SIZE);
if (size < expected) {
debug("TPM error, unable to read remaining bytes of result\n");
size = -EIO;
goto out;
}
out:
st33zp24_spi_cancel(dev);
st33zp24_spi_release_locality(dev);
return size;
}
/*
* st33zp24_spi_send send TPM commands through TPM phy.
* @param: chip, tpm_chip description.
* @param: buf, the buffer to send.
* @param: len, the number of bytes to send.
* @return: Returns zero in case of success else the negative error code.
*/
static int st33zp24_spi_send(struct udevice *dev, const u8 *buf, size_t len)
{
struct tpm_chip *chip = dev_get_priv(dev);
u32 i, size;
int burstcnt, ret, status;
u8 data, tpm_stat;
if (!chip)
return -ENODEV;
if (len < TPM_HEADER_SIZE)
return -EIO;
ret = st33zp24_spi_request_locality(dev);
if (ret < 0)
return ret;
tpm_stat = st33zp24_spi_status(dev);
if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
st33zp24_spi_cancel(dev);
if (st33zp24_spi_wait_for_stat(dev, TPM_STS_COMMAND_READY,
chip->timeout_b, &status) < 0) {
ret = -ETIME;
goto out_err;
}
}
for (i = 0; i < len - 1;) {
burstcnt = st33zp24_spi_get_burstcount(dev);
if (burstcnt < 0)
return burstcnt;
size = min_t(int, len - i - 1, burstcnt);
ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + i, size);
if (ret < 0)
goto out_err;
i += size;
}
tpm_stat = st33zp24_spi_status(dev);
if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
ret = -EIO;
goto out_err;
}
ret = st33zp24_spi_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
if (ret < 0)
goto out_err;
tpm_stat = st33zp24_spi_status(dev);
if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
ret = -EIO;
goto out_err;
}
data = TPM_STS_GO;
ret = st33zp24_spi_write(dev, TPM_STS, &data, 1);
if (ret < 0)
goto out_err;
return len;
out_err:
st33zp24_spi_cancel(dev);
st33zp24_spi_release_locality(dev);
return ret;
}
static int st33zp24_spi_cleanup(struct udevice *dev)
{
st33zp24_spi_cancel(dev);
/*
* The TPM needs some time to clean up here,
* so we sleep rather than keeping the bus busy
*/
mdelay(2);
st33zp24_spi_release_locality(dev);
return 0;
}
static int st33zp24_spi_init(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
struct st33zp24_spi_phy *phy = dev_get_platdata(dev);
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;
chip->locality = LOCALITY0;
phy->latency = st33zp24_spi_evaluate_latency(dev);
if (phy->latency <= 0)
return -ENODEV;
/*
* A timeout query to TPM can be placed here.
* Standard timeout values are used so far
*/
return 0;
}
static int st33zp24_spi_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 = st33zp24_spi_init(dev);
if (rc < 0)
chip->is_open = 0;
return rc;
}
static int st33zp24_spi_close(struct udevice *dev)
{
struct tpm_chip *chip = dev_get_priv(dev);
if (chip->is_open) {
st33zp24_spi_release_locality(dev);
chip->is_open = 0;
chip->vend_dev = 0;
}
return 0;
}
static int st33zp24_spi_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",
dev->name,
chip->vend_dev >> 16);
}
const struct tpm_ops st33zp24_spi_tpm_ops = {
.open = st33zp24_spi_open,
.close = st33zp24_spi_close,
.recv = st33zp24_spi_recv,
.send = st33zp24_spi_send,
.cleanup = st33zp24_spi_cleanup,
.get_desc = st33zp24_spi_get_desc,
};
static int st33zp24_spi_probe(struct udevice *dev)
{
struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
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;
debug("ST33ZP24 SPI TPM from STMicroelectronics found\n");
return 0;
}
static int st33zp24_spi_remove(struct udevice *dev)
{
st33zp24_spi_release_locality(dev);
return 0;
}
static const struct udevice_id st33zp24_spi_ids[] = {
{ .compatible = "st,st33zp24-spi" },
{ }
};
U_BOOT_DRIVER(st33zp24_spi_spi) = {
.name = "st33zp24-spi",
.id = UCLASS_TPM,
.of_match = of_match_ptr(st33zp24_spi_ids),
.probe = st33zp24_spi_probe,
.remove = st33zp24_spi_remove,
.ops = &st33zp24_spi_tpm_ops,
.priv_auto_alloc_size = sizeof(struct tpm_chip),
.platdata_auto_alloc_size = sizeof(struct st33zp24_spi_phy),
};