blob: 7f8df3183309e650262de0367649a10b2e8a46b6 [file] [log] [blame]
// 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/bitops.h>
#include <linux/delay.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"
#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, u32 addr, u16 len, u8 *in)
{
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, sizeof(u32), (u8 *)&result_le);
if (!ret)
*result = le32_to_cpu(result_le);
return ret;
}
static int tpm_tis_spi_write(struct udevice *dev, u32 addr, u16 len, const u8 *out)
{
return tpm_tis_spi_xfer(dev, addr, out, NULL, len);
}
static int tpm_tis_spi_write32(struct udevice *dev, u32 addr, u32 value)
{
__le32 value_le = cpu_to_le32(value);
return tpm_tis_spi_write(dev, addr, sizeof(value), (u8 *)&value_le);
}
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), 1, &status);
if (ret)
break;
if (status & TPM_ACCESS_VALID)
return 0;
} while (get_timer(start) < stop);
return -EIO;
}
static struct tpm_tis_phy_ops phy_ops = {
.read_bytes = tpm_tis_spi_read,
.write_bytes = tpm_tis_spi_write,
.read32 = tpm_tis_spi_read32,
.write32 = tpm_tis_spi_write32,
};
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;
/* Use the TPM v2 stack */
priv->version = TPM_V2;
if (CONFIG_IS_ENABLED(DM_GPIO)) {
struct gpio_desc reset_gpio;
ret = gpio_request_by_name(dev, "reset-gpios", 0,
&reset_gpio, GPIOD_IS_OUT);
if (ret) {
/* legacy reset */
ret = gpio_request_by_name(dev, "gpio-reset", 0,
&reset_gpio, GPIOD_IS_OUT);
if (!ret) {
log(LOGC_NONE, LOGL_NOTICE,
"%s: gpio-reset is deprecated\n", __func__);
}
}
if (!ret) {
log(LOGC_NONE, LOGL_WARNING,
"%s: TPM gpio reset should not be used on secure production devices\n",
dev->name);
dm_gpio_set_value(&reset_gpio, 1);
mdelay(1);
dm_gpio_set_value(&reset_gpio, 0);
}
}
/* Ensure a minimum amount of time elapsed since reset of the TPM */
mdelay(drv_data->time_before_first_cmd_ms);
ret = tpm_tis_wait_init(dev, chip->locality);
if (ret) {
log(LOGC_DM, LOGL_ERR, "%s: no device found\n", __func__);
return ret;
}
tpm_tis_ops_register(dev, &phy_ops);
ret = tpm_tis_init(dev);
if (ret)
goto err;
priv->pcr_count = drv_data->pcr_count;
priv->pcr_select_min = drv_data->pcr_select_min;
priv->version = TPM_V2;
return 0;
err:
return -EINVAL;
}
static int tpm_tis_spi_remove(struct udevice *udev)
{
return tpm_tis_cleanup(udev);
}
static const struct tpm_ops tpm_tis_spi_ops = {
.open = tpm_tis_open,
.close = tpm_tis_close,
.get_desc = tpm_tis_get_desc,
.send = tpm_tis_send,
.recv = tpm_tis_recv,
.cleanup = tpm_tis_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 = "tcg,tpm_tis-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 = sizeof(struct tpm_chip),
};