[U-Boot] [PATCH v4 25/32] tpm: add support for TPMv2.x SPI modules

Miquel Raynal
2018-05-15T09:57:21Z

Add the tpm2_tis_spi driver that should support any TPMv2 compliant
(SPI) module.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
drivers/tpm/Kconfig | 10 +
drivers/tpm/Makefile | 2 +
drivers/tpm/tpm2_tis_spi.c | 664 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 676 insertions(+)
create mode 100644 drivers/tpm/tpm2_tis_spi.c

diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index 01967ffd35..6661dcc1e3 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -141,6 +141,16 @@ config TPM_V2

if TPM_V2 && !TPM_V1

+config TPM2_TIS_SPI
+ bool "Enable support for TPMv2.x SPI chips"
+ depends on TPM_V2 && DM_SPI
+ select TPM_DRIVER_SELECTED
+ help
+ This driver supports TPMv2.x devices connected on the SPI bus.
+ The usual TPM operations and the 'tpm' command can be used to talk
+ to the device using the standard TPM Interface Specification (TIS)
+ protocol.
+
endif # TPM_V2

endmenu
diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
index c42a93f267..2c88b64659 100644
--- a/drivers/tpm/Makefile
+++ b/drivers/tpm/Makefile
@@ -11,3 +11,5 @@ obj-$(CONFIG_TPM_TIS_LPC) += tpm_tis_lpc.o
obj-$(CONFIG_TPM_TIS_SANDBOX) += tpm_tis_sandbox.o
obj-$(CONFIG_TPM_ST33ZP24_I2C) += tpm_tis_st33zp24_i2c.o
obj-$(CONFIG_TPM_ST33ZP24_SPI) += tpm_tis_st33zp24_spi.o
+
+obj-$(CONFIG_TPM2_TIS_SPI) += tpm2_tis_spi.o
diff --git a/drivers/tpm/tpm2_tis_spi.c b/drivers/tpm/tpm2_tis_spi.c
new file mode 100644
index 0000000000..6a4d5284c9
--- /dev/null
+++ b/drivers/tpm/tpm2_tis_spi.c
@@ -0,0 +1,664 @@
+/*
+ * 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.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#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 "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@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;
+
+ /* 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),
+};
--
2.14.1