tpm: add support for TPMv2.x SPI modules

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

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/tpm/Kconfig

@@ -129,6 +129,16 @@ 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

drivers/tpm/Makefile

@@ -9,3 +9,5 @@ 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

drivers/tpm/tpm2_tis_spi.c

@@ -0,0 +1,663 @@
+// 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 "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;
+
+	/* 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),
+};