--- /dev/null
+/*
+ * STMicroelectronics TPM ST33ZP24 SPI UBOOT driver
+ *
+ * Copyright (C) 2016 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.
+ *
+ * SPDX-License-Identifier: GPL-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, 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) {
+ 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),
+};
projects / u-boot.git / commitdiff
