[PATCH u-boot v2019.04-aspeed-openbmc 0/5] ast2600: Add I2C TPMv2 driver

[PATCH u-boot v2019.04-aspeed-openbmc 0/5] ast2600: Add I2C TPMv2 driver

[Eddie James]

This series fixes the AST2XXX I2C driver to work with clock-stretching
devices and adds a TPMv2 driver for the NPCT75X device. Enable the TPM on
the Rainier system and add a board init function to write PCR0 of the TPM.

Eddie James (5):
  i2c: ast_i2c: Remove SCL direct drive mode
  tpm: Add I2C driver for TPMv2 devices
  arm: dts: ast2600-rainier: Add NPCT75X TPM
  configs: ast2600_openbmc_spl_emmc: Enable TPMv2 over I2C
  aspeed: Add board_late_init to write TPM

 arch/arm/dts/ast2600-rainier.dts           |  12 +-
 board/aspeed/evb_ast2600/evb_ast2600.c     |  34 ++
 configs/ast2600_openbmc_spl_emmc_defconfig |   3 +-
 drivers/i2c/ast_i2c.c                      |   2 +-
 drivers/tpm/Kconfig                        |   9 +
 drivers/tpm/Makefile                       |   1 +
 drivers/tpm/tpm2_tis_i2c.c                 | 593 +++++++++++++++++++++
 7 files changed, 647 insertions(+), 7 deletions(-)
 create mode 100644 drivers/tpm/tpm2_tis_i2c.c

-- 
2.27.0

[PATCH u-boot v2019.04-aspeed-openbmc 1/5] i2c: ast_i2c: Remove SCL direct drive mode

[Eddie James]

SCL direct drive mode prevents communication with devices that
do clock stretching, so disable. The Linux driver doesn't use
this mode, and the engine can handle clock stretching.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/i2c/ast_i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/ast_i2c.c b/drivers/i2c/ast_i2c.c
index bbc32d6cdb..13420ade84 100644
--- a/drivers/i2c/ast_i2c.c
+++ b/drivers/i2c/ast_i2c.c
@@ -73,7 +73,7 @@ static void ast_i2c_init_bus(struct udevice *dev)
 	/* Enable Master Mode. Assuming single-master */
 	writel(I2CD_MASTER_EN
 	       | I2CD_M_SDA_LOCK_EN
-	       | I2CD_MULTI_MASTER_DIS | I2CD_M_SCL_DRIVE_EN,
+	       | I2CD_MULTI_MASTER_DIS,
 	       &priv->regs->fcr);
 	/* Enable Interrupts */
 	writel(I2CD_INTR_TX_ACK
-- 
2.27.0

Re: [PATCH u-boot v2019.04-aspeed-openbmc 1/5] i2c: ast_i2c: Remove SCL direct drive mode

[Joel Stanley]

On Thu, 5 May 2022 at 20:28, Eddie James <eajames@linux.ibm.com> wrote:
>
> SCL direct drive mode prevents communication with devices that
> do clock stretching, so disable. The Linux driver doesn't use
> this mode, and the engine can handle clock stretching.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
>  drivers/i2c/ast_i2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/ast_i2c.c b/drivers/i2c/ast_i2c.c
> index bbc32d6cdb..13420ade84 100644
> --- a/drivers/i2c/ast_i2c.c
> +++ b/drivers/i2c/ast_i2c.c
> @@ -73,7 +73,7 @@ static void ast_i2c_init_bus(struct udevice *dev)
>         /* Enable Master Mode. Assuming single-master */
>         writel(I2CD_MASTER_EN
>                | I2CD_M_SDA_LOCK_EN
> -              | I2CD_MULTI_MASTER_DIS | I2CD_M_SCL_DRIVE_EN,
> +              | I2CD_MULTI_MASTER_DIS,

This driver is upstream, so it can be submitted there too.

>                &priv->regs->fcr);
>         /* Enable Interrupts */
>         writel(I2CD_INTR_TX_ACK
> --
> 2.27.0
>

[PATCH u-boot v2019.04-aspeed-openbmc 2/5] tpm: Add I2C driver for TPMv2 devices

[Eddie James]

Add a driver to communicate with TPMv2 chips over I2C, such
as the NPCT75X.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/tpm/Kconfig        |   9 +
 drivers/tpm/Makefile       |   1 +
 drivers/tpm/tpm2_tis_i2c.c | 593 +++++++++++++++++++++++++++++++++++++
 3 files changed, 603 insertions(+)
 create mode 100644 drivers/tpm/tpm2_tis_i2c.c

diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index 94629dffd2..6fd98ac057 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -145,6 +145,15 @@ config TPM2_TIS_SPI
 	  to the device using the standard TPM Interface Specification (TIS)
 	  protocol.
 
+config TPM2_TIS_I2C
+	bool "Enable support for TPMv2.x I2C chips"
+	depends on TPM_V2 && DM_I2C
+	help
+	  This driver supports TPMv2.x devices connected on the I2C 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 94c337b8ed..220f03253c 100644
--- a/drivers/tpm/Makefile
+++ b/drivers/tpm/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_TPM_ST33ZP24_SPI) += tpm_tis_st33zp24_spi.o
 
 obj-$(CONFIG_TPM2_TIS_SANDBOX) += tpm2_tis_sandbox.o
 obj-$(CONFIG_TPM2_TIS_SPI) += tpm2_tis_spi.o
+obj-$(CONFIG_TPM2_TIS_I2C) += tpm2_tis_i2c.o
diff --git a/drivers/tpm/tpm2_tis_i2c.c b/drivers/tpm/tpm2_tis_i2c.c
new file mode 100644
index 0000000000..5fab9122e6
--- /dev/null
+++ b/drivers/tpm/tpm2_tis_i2c.c
@@ -0,0 +1,593 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <tpm-v1.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"
+
+enum i2c_chip_type {
+	NPCT75X,
+	UNKNOWN,
+};
+
+/* expected value for DIDVID register */
+#define TPM2_TIS_I2C_DID_VID_NPCT75X 0x5010FC00L
+
+static const char * const chip_name[] = {
+	[NPCT75X] = "npct75X",
+	[UNKNOWN] = "unknown/fallback to npct75X",
+};
+
+#define TPM_LOC_SEL		0x00
+#define	TPM_ACCESS		0x04
+#define	TPM_STS			0x18
+#define	TPM_DATA_FIFO		0x24
+#define	TPM_DID_VID		0x48
+
+/*
+ * tpm2_tis_i2c_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 tpm2_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer,
+			     size_t len)
+{
+	int rc;
+	int count;
+
+	for (count = 0; count < MAX_COUNT; count++) {
+		rc = dm_i2c_read(dev, addr, buffer, len);
+		if (rc == 0) {
+			debug("read addr[%02x] len[%u] data[%02x %02x %02x %02x%s]\n", addr, len, len > 0 ? buffer[0] : 0, len > 1 ? buffer[1] : 0, len > 2 ? buffer[2] : 0, len > 3 ? buffer[3] : 0, len > 4 ? " ..." : "");
+			break;  /* break here to skip sleep */
+		}
+		udelay(SLEEP_DURATION_US);
+	}
+
+	/* Take care of 'guard time' */
+	udelay(SLEEP_DURATION_US);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static int tpm2_tis_i2c_write_generic(struct udevice *dev, u8 addr,
+				      const u8 *buffer, size_t len,
+				      unsigned int sleep_time_us, u8 max_count)
+{
+	int rc = 0;
+	int count;
+
+	for (count = 0; count < max_count; count++) {
+		rc = dm_i2c_write(dev, addr, buffer, len);
+		if (rc == 0) {
+			debug("write addr[%02x] len[%u] data[%02x %02x %02x %02x%s]\n", addr, len, len > 0 ? buffer[0] : 0, len > 1 ? buffer[1] : 0, len > 2 ? buffer[2] : 0, len > 3 ? buffer[3] : 0, len > 4 ? " ..." : "");
+			break;  /* Success, break to skip sleep */
+		}
+		udelay(sleep_time_us);
+	}
+
+	/* take care of 'guard time' */
+	udelay(sleep_time_us);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+/*
+ * tpm2_tis_i2c_write() - write to TPM register
+ * @addr: register address to write to
+ * @buffer: containing data to be written
+ * @len: number of bytes to write
+ *
+ * Write len bytes from provided buffer to TPM register (little
+ * endian format, i.e. buffer[0] is written as first byte).
+ *
+ * NOTE: TPM is big-endian for multi-byte values. Multi-byte
+ * values have to be swapped.
+ *
+ * NOTE: use this function instead of the tpm2_tis_i2c_write_generic function.
+ *
+ * Return -EIO on error, 0 on success
+ */
+static int tpm2_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer,
+			      size_t len)
+{
+	return tpm2_tis_i2c_write_generic(dev, addr, buffer, len,
+					  SLEEP_DURATION_US, MAX_COUNT);
+}
+
+/*
+ * This function is needed especially for the cleanup situation after
+ * sending TPM_READY
+ */
+static int tpm2_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer,
+				   size_t len)
+{
+	return tpm2_tis_i2c_write_generic(dev, addr, buffer, len,
+					  SLEEP_DURATION_LONG_US,
+					  MAX_COUNT_LONG);
+}
+
+static int tpm2_tis_i2c_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 rc;
+
+	buf = loc;
+	rc = tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1);
+	if (rc < 0)
+		return rc;
+
+	rc = tpm2_tis_i2c_read(dev, TPM_ACCESS, &buf, 1);
+	if (rc < 0)
+		return rc;
+
+	if ((buf & mask) == mask) {
+		chip->locality = loc;
+		return loc;
+	}
+
+	return -ENOENT;
+}
+
+static void tpm2_tis_i2c_release_locality(struct udevice *dev, int loc,
+					 int force)
+{
+	const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
+	u8 buf;
+
+	buf = loc;
+	if (tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1) < 0)
+		return;
+
+	if (tpm2_tis_i2c_read(dev, TPM_ACCESS, &buf, 1) < 0)
+		return;
+
+	if (force || (buf & mask) == mask) {
+		buf = TPM_ACCESS_ACTIVE_LOCALITY;
+		tpm2_tis_i2c_write(dev, TPM_ACCESS, &buf, 1);
+	}
+}
+
+static int tpm2_tis_i2c_request_locality(struct udevice *dev, int loc)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	unsigned long start, stop;
+	u8 buf = 0;
+	int rc;
+
+	rc = tpm2_tis_i2c_check_locality(dev, loc);
+	if (rc >= 0) {
+		debug("%s: Already have locality\n", __func__);
+		return loc;  /* We already have the locality */
+	} else if (rc != -ENOENT) {
+		debug("%s: Failed to get locality: %d\n", __func__, rc);
+		return rc;
+	}
+
+	buf = loc;
+	rc = tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1);
+	if (rc) {
+		debug("%s: Failed to write to TPM: %d\n", __func__, rc);
+		return rc;
+	}
+
+	buf = TPM_ACCESS_REQUEST_USE;
+	rc = tpm2_tis_i2c_write(dev, TPM_ACCESS, &buf, 1);
+	if (rc) {
+		debug("%s: Failed to write to TPM: %d\n", __func__, rc);
+		return rc;
+	}
+
+	/* Wait for burstcount */
+	start = get_timer(0);
+	stop = chip->timeout_a;
+	do {
+		rc = tpm2_tis_i2c_check_locality(dev, loc);
+		if (rc >= 0) {
+			debug("%s: Have locality\n", __func__);
+			return loc;
+		} else if (rc != -ENOENT) {
+			debug("%s: Failed to get locality: %d\n", __func__, rc);
+			return rc;
+		}
+		mdelay(TPM_TIMEOUT_MS);
+	} while (get_timer(start) < stop);
+	debug("%s: Timeout getting locality: %d\n", __func__, rc);
+
+	return rc;
+}
+
+static u8 tpm2_tis_i2c_status(struct udevice *dev)
+{
+	/* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
+	u8 buf;
+
+	if (tpm2_tis_i2c_read(dev, TPM_STS, &buf, 1) < 0)
+		return 0;
+	else
+		return buf;
+}
+
+static int tpm2_tis_i2c_ready(struct udevice *dev)
+{
+	int rc;
+
+	/* This causes the current command to be aborted */
+	u8 buf = TPM_STS_COMMAND_READY;
+
+	debug("%s\n", __func__);
+	rc = tpm2_tis_i2c_write_long(dev, TPM_STS, &buf, 1);
+	if (rc)
+		debug("%s: rc=%d\n", __func__, rc);
+
+	return rc;
+}
+
+static ssize_t tpm2_tis_i2c_get_burstcount(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	unsigned long start, stop;
+	ssize_t burstcnt;
+	u8 addr, buf[3];
+
+	/* Wait for burstcount */
+	/* XXX: Which timeout value? Spec has 2 answers (c & d) */
+	start = get_timer(0);
+	stop = chip->timeout_d;
+	do {
+		/* Note: STS is little endian */
+		addr = TPM_STS + 1;
+		if (tpm2_tis_i2c_read(dev, addr, buf, 2) < 0)
+			burstcnt = 0;
+		else
+			burstcnt = (buf[1] << 8) + buf[0];
+
+		if (burstcnt)
+			return burstcnt;
+		mdelay(TPM_TIMEOUT_MS);
+	} while (get_timer(start) < stop);
+
+	return -EBUSY;
+}
+
+static int tpm2_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask,
+				      unsigned long timeout, int *status)
+{
+	unsigned long start, stop;
+
+	/* Check current status */
+	*status = tpm2_tis_i2c_status(dev);
+	if ((*status & mask) == mask)
+		return 0;
+
+	start = get_timer(0);
+	stop = timeout;
+	do {
+		mdelay(TPM_TIMEOUT_MS);
+		*status = tpm2_tis_i2c_status(dev);
+		if ((*status & mask) == mask)
+			return 0;
+	} while (get_timer(start) < stop);
+
+	return -ETIMEDOUT;
+}
+
+static int tpm2_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
+{
+	size_t size = 0;
+	ssize_t burstcnt;
+	int rc;
+
+	while (size < count) {
+		burstcnt = tpm2_tis_i2c_get_burstcount(dev);
+
+		/* burstcount < 0 -> tpm is busy */
+		if (burstcnt < 0)
+			return burstcnt;
+
+		/* Limit received data to max left */
+		if (burstcnt > (count - size))
+			burstcnt = count - size;
+
+		rc = tpm2_tis_i2c_read(dev, TPM_DATA_FIFO,
+				       &(buf[size]), burstcnt);
+		if (rc == 0)
+			size += burstcnt;
+	}
+
+	return size;
+}
+
+static int tpm2_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	int size = 0;
+	int status;
+	unsigned int expected;
+	int rc;
+
+	status = tpm2_tis_i2c_status(dev);
+	if (status == TPM_STS_COMMAND_READY)
+		return -EINTR;
+	if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) !=
+	    (TPM_STS_DATA_AVAIL | TPM_STS_VALID))
+		return -EAGAIN;
+
+	debug("...got it;\n");
+
+	/* Read first 10 bytes, including tag, paramsize, and result */
+	size = tpm2_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
+	if (size < TPM_HEADER_SIZE) {
+		debug("Unable to read header\n");
+		return size < 0 ? size : -EIO;
+	}
+
+	expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
+	if ((size_t)expected > count || (size_t)expected < TPM_HEADER_SIZE) {
+		debug("Error size=%x, expected=%x, count=%x\n", size, expected,
+		      count);
+		return -ENOSPC;
+	}
+
+	size += tpm2_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
+				       expected - TPM_HEADER_SIZE);
+	if (size < expected) {
+		debug("Unable to read remainder of result\n");
+		return -ETIMEDOUT;
+	}
+
+	rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c,
+					&status);
+	if (rc)
+		return rc;
+	if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
+		debug("Error left over data\n");
+		return -EIO;
+	}
+
+	return size;
+}
+
+static int tpm2_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	int rc, status;
+	size_t burstcnt;
+	size_t count = 0;
+	int retry = 0;
+	u8 sts = TPM_STS_GO;
+
+	debug("%s: len=%d\n", __func__, len);
+	if (len > TPM_DEV_BUFSIZE)
+		return -E2BIG;  /* Command is too long for our tpm, sorry */
+
+	if (tpm2_tis_i2c_request_locality(dev, 0) < 0)
+		return -EBUSY;
+
+	status = tpm2_tis_i2c_status(dev);
+	if ((status & TPM_STS_COMMAND_READY) == 0) {
+		rc = tpm2_tis_i2c_ready(dev);
+		if (rc)
+			return rc;
+		rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
+						chip->timeout_b, &status);
+		if (rc)
+			return rc;
+	}
+
+	burstcnt = tpm2_tis_i2c_get_burstcount(dev);
+
+	/* burstcount < 0 -> tpm is busy */
+	if (burstcnt < 0)
+		return burstcnt;
+
+	while (count < len) {
+		udelay(300);
+		if (burstcnt > len - count)
+			burstcnt = len - count;
+
+#ifdef CONFIG_TPM2_TIS_I2C_BURST_LIMITATION
+		if (retry && burstcnt > CONFIG_TPM2_TIS_I2C_BURST_LIMITATION_LEN)
+			burstcnt = CONFIG_TPM2_TIS_I2C_BURST_LIMITATION_LEN;
+#endif /* CONFIG_TPM2_TIS_I2C_BURST_LIMITATION */
+
+		rc = tpm2_tis_i2c_write(dev, TPM_DATA_FIFO,
+					&(buf[count]), burstcnt);
+		if (rc == 0)
+			count += burstcnt;
+		else {
+			debug("%s: error\n", __func__);
+			if (retry++ > 10)
+				return -EIO;
+			rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_VALID,
+							chip->timeout_c,
+							&status);
+			if (rc)
+				return rc;
+
+			if ((status & TPM_STS_DATA_EXPECT) == 0)
+				return -EIO;
+		}
+	}
+
+	/* Go and do it */
+	rc = tpm2_tis_i2c_write(dev, TPM_STS, &sts, 1);
+	if (rc < 0)
+		return rc;
+	debug("%s: done, rc=%d\n", __func__, rc);
+
+	return len;
+}
+
+static int tpm2_tis_i2c_cleanup(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	tpm2_tis_i2c_ready(dev);
+	/*
+	 * The TPM needs some time to clean up here,
+	 * so we sleep rather than keeping the bus busy
+	 */
+	mdelay(2);
+	tpm2_tis_i2c_release_locality(dev, chip->locality, 0);
+
+	return 0;
+}
+
+static int tpm2_tis_i2c_init(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	u32 vendor;
+	u32 expected_did_vid;
+	int rc;
+
+	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;
+
+	rc = tpm2_tis_i2c_request_locality(dev, 0);
+	if (rc < 0)
+		return rc;
+
+	/* Read four bytes from DID_VID register */
+	if (tpm2_tis_i2c_read(dev, TPM_DID_VID, (uchar *)&vendor, 4) < 0) {
+		tpm2_tis_i2c_release_locality(dev, 0, 1);
+		return -EIO;
+	}
+
+	if (chip->chip_type == NPCT75X) {
+		vendor = be32_to_cpu(vendor);
+		expected_did_vid = TPM2_TIS_I2C_DID_VID_NPCT75X;
+	}
+
+	if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) {
+		pr_err("Vendor id did not match! ID was %08x\n", vendor);
+		return -ENODEV;
+	}
+
+	chip->vend_dev = vendor;
+	debug("2.0 TPM (chip type %s device-id 0x%X)\n",
+	      chip_name[chip->chip_type], vendor >> 16);
+
+	/*
+	 * A timeout query to TPM can be placed here.
+	 * Standard timeout values are used so far
+	 */
+
+	return 0;
+}
+
+static int tpm2_tis_i2c_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 = tpm2_tis_i2c_init(dev);
+	if (rc < 0)
+		chip->is_open = 0;
+
+	return rc;
+}
+
+static int tpm2_tis_i2c_close(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	if (chip->is_open) {
+		tpm2_tis_i2c_release_locality(dev, chip->locality, 1);
+		chip->is_open = 0;
+		chip->vend_dev = 0;
+	}
+
+	return 0;
+}
+
+static int tpm2_tis_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, "2.0 TPM (%s, chip type %s device-id 0x%x)",
+			chip->is_open ? "open" : "closed",
+			chip_name[chip->chip_type],
+			chip->vend_dev >> 16);
+}
+
+static int tpm2_tis_i2c_probe(struct udevice *dev)
+{
+	struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	chip->chip_type = dev_get_driver_data(dev);
+	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;
+
+	/* TODO: These need to be checked and tuned */
+	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;
+	uc_priv->pcr_count = 24;
+	uc_priv->pcr_select_min = 3;
+	uc_priv->version = TPM_V2;
+
+	return 0;
+}
+
+static const struct tpm_ops tpm2_tis_i2c_ops = {
+	.open		= tpm2_tis_i2c_open,
+	.close		= tpm2_tis_i2c_close,
+	.get_desc	= tpm2_tis_get_desc,
+	.send		= tpm2_tis_i2c_send,
+	.recv		= tpm2_tis_i2c_recv,
+	.cleanup	= tpm2_tis_i2c_cleanup,
+};
+
+static const struct udevice_id tpm2_tis_i2c_ids[] = {
+	{ .compatible = "nuvoton,npct75x", .data = NPCT75X },
+	{ }
+};
+
+U_BOOT_DRIVER(tpm2_tis_i2c) = {
+	.name   = "tpm2_tis_i2c",
+	.id     = UCLASS_TPM,
+	.of_match = tpm2_tis_i2c_ids,
+	.ops    = &tpm2_tis_i2c_ops,
+	.probe	= tpm2_tis_i2c_probe,
+	.priv_auto_alloc_size = sizeof(struct tpm_chip),
+};
-- 
2.27.0

Re: [PATCH u-boot v2019.04-aspeed-openbmc 2/5] tpm: Add I2C driver for TPMv2 devices

[Joel Stanley]

On Thu, 5 May 2022 at 20:28, Eddie James <eajames@linux.ibm.com> wrote:
>
> Add a driver to communicate with TPMv2 chips over I2C, such
> as the NPCT75X.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
>  drivers/tpm/Kconfig        |   9 +
>  drivers/tpm/Makefile       |   1 +
>  drivers/tpm/tpm2_tis_i2c.c | 593 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 603 insertions(+)
>  create mode 100644 drivers/tpm/tpm2_tis_i2c.c
>
> diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
> index 94629dffd2..6fd98ac057 100644
> --- a/drivers/tpm/Kconfig
> +++ b/drivers/tpm/Kconfig
> @@ -145,6 +145,15 @@ config TPM2_TIS_SPI
>           to the device using the standard TPM Interface Specification (TIS)
>           protocol.
>
> +config TPM2_TIS_I2C
> +       bool "Enable support for TPMv2.x I2C chips"
> +       depends on TPM_V2 && DM_I2C
> +       help
> +         This driver supports TPMv2.x devices connected on the I2C 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 94c337b8ed..220f03253c 100644
> --- a/drivers/tpm/Makefile
> +++ b/drivers/tpm/Makefile
> @@ -12,3 +12,4 @@ obj-$(CONFIG_TPM_ST33ZP24_SPI) += tpm_tis_st33zp24_spi.o
>
>  obj-$(CONFIG_TPM2_TIS_SANDBOX) += tpm2_tis_sandbox.o
>  obj-$(CONFIG_TPM2_TIS_SPI) += tpm2_tis_spi.o
> +obj-$(CONFIG_TPM2_TIS_I2C) += tpm2_tis_i2c.o
> diff --git a/drivers/tpm/tpm2_tis_i2c.c b/drivers/tpm/tpm2_tis_i2c.c
> new file mode 100644
> index 0000000000..5fab9122e6
> --- /dev/null
> +++ b/drivers/tpm/tpm2_tis_i2c.c
> @@ -0,0 +1,593 @@
> +// SPDX-License-Identifier: GPL-2.0

Add:

Copyright 2022 IBM Corp.

> +
> +#include <common.h>
> +#include <dm.h>
> +#include <fdtdec.h>
> +#include <i2c.h>
> +#include <tpm-v1.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"
> +
> +enum i2c_chip_type {
> +       NPCT75X,
> +       UNKNOWN,
> +};
> +
> +/* expected value for DIDVID register */
> +#define TPM2_TIS_I2C_DID_VID_NPCT75X 0x5010FC00L
> +
> +static const char * const chip_name[] = {
> +       [NPCT75X] = "npct75X",
> +       [UNKNOWN] = "unknown/fallback to npct75X",
> +};
> +
> +#define TPM_LOC_SEL            0x00
> +#define        TPM_ACCESS              0x04
> +#define        TPM_STS                 0x18
> +#define        TPM_DATA_FIFO           0x24
> +#define        TPM_DID_VID             0x48
> +
> +/*
> + * tpm2_tis_i2c_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 tpm2_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer,
> +                            size_t len)
> +{
> +       int rc;
> +       int count;
> +
> +       for (count = 0; count < MAX_COUNT; count++) {
> +               rc = dm_i2c_read(dev, addr, buffer, len);
> +               if (rc == 0) {
> +                       debug("read addr[%02x] len[%u] data[%02x %02x %02x %02x%s]\n", addr, len, len > 0 ? buffer[0] : 0, len > 1 ? buffer[1] : 0, len > 2 ? buffer[2] : 0, len > 3 ? buffer[3] : 0, len > 4 ? " ..." : "");
> +                       break;  /* break here to skip sleep */
> +               }
> +               udelay(SLEEP_DURATION_US);
> +       }
> +
> +       /* Take care of 'guard time' */
> +       udelay(SLEEP_DURATION_US);

This will sleep again if the read has reached MAX_COUNT. Could it
return an error straight away? Or is this a TPM spec thing?

Why are you looping several times? Is that a TPM spec thing?

The kernel does this:

do {
 ret = i2c_transfer()
 sleep(GUARD_TIME)
} while (ret < 0 && count++ < GUARD_TIME)

Which makes more sense.

> +       if (rc)
> +               return rc;
> +
> +       return 0;
> +}
> +
> +static int tpm2_tis_i2c_write_generic(struct udevice *dev, u8 addr,
> +                                     const u8 *buffer, size_t len,
> +                                     unsigned int sleep_time_us, u8 max_count)
> +{
> +       int rc = 0;
> +       int count;
> +
> +       for (count = 0; count < max_count; count++) {
> +               rc = dm_i2c_write(dev, addr, buffer, len);
> +               if (rc == 0) {
> +                       debug("write addr[%02x] len[%u] data[%02x %02x %02x %02x%s]\n", addr, len, len > 0 ? buffer[0] : 0, len > 1 ? buffer[1] : 0, len > 2 ? buffer[2] : 0, len > 3 ? buffer[3] : 0, len > 4 ? " ..." : "");
> +                       break;  /* Success, break to skip sleep */
> +               }
> +               udelay(sleep_time_us);
> +       }
> +
> +       /* take care of 'guard time' */
> +       udelay(sleep_time_us);
> +       if (rc)
> +               return rc;
> +
> +       return 0;
> +}
> +
> +/*
> + * tpm2_tis_i2c_write() - write to TPM register
> + * @addr: register address to write to
> + * @buffer: containing data to be written
> + * @len: number of bytes to write
> + *
> + * Write len bytes from provided buffer to TPM register (little
> + * endian format, i.e. buffer[0] is written as first byte).
> + *
> + * NOTE: TPM is big-endian for multi-byte values. Multi-byte
> + * values have to be swapped.
> + *
> + * NOTE: use this function instead of the tpm2_tis_i2c_write_generic function.

Why the extra indirection?

Actually, I see why. This code is a copy of
drivers/tpm/tpm_tis_infineon.c with some things changed. Can you go
through the patch and remove things that don't need to be in this
driver?

The kernel driver is a good reference for things that might be
required for the spec, vs coding decisions made by the infineon driver
author.


> + *
> + * Return -EIO on error, 0 on success
> + */
> +static int tpm2_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer,
> +                             size_t len)
> +{
> +       return tpm2_tis_i2c_write_generic(dev, addr, buffer, len,
> +                                         SLEEP_DURATION_US, MAX_COUNT);
> +}
> +
> +/*
> + * This function is needed especially for the cleanup situation after
> + * sending TPM_READY
> + */
> +static int tpm2_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer,
> +                                  size_t len)
> +{
> +       return tpm2_tis_i2c_write_generic(dev, addr, buffer, len,
> +                                         SLEEP_DURATION_LONG_US,
> +                                         MAX_COUNT_LONG);
> +}
> +
> +static int tpm2_tis_i2c_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 rc;
> +
> +       buf = loc;
> +       rc = tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1);
> +       if (rc < 0)
> +               return rc;
> +
> +       rc = tpm2_tis_i2c_read(dev, TPM_ACCESS, &buf, 1);
> +       if (rc < 0)
> +               return rc;
> +
> +       if ((buf & mask) == mask) {
> +               chip->locality = loc;
> +               return loc;
> +       }
> +
> +       return -ENOENT;
> +}
> +
> +static void tpm2_tis_i2c_release_locality(struct udevice *dev, int loc,
> +                                        int force)
> +{
> +       const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
> +       u8 buf;
> +
> +       buf = loc;
> +       if (tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1) < 0)
> +               return;
> +
> +       if (tpm2_tis_i2c_read(dev, TPM_ACCESS, &buf, 1) < 0)
> +               return;
> +
> +       if (force || (buf & mask) == mask) {
> +               buf = TPM_ACCESS_ACTIVE_LOCALITY;
> +               tpm2_tis_i2c_write(dev, TPM_ACCESS, &buf, 1);
> +       }
> +}
> +
> +static int tpm2_tis_i2c_request_locality(struct udevice *dev, int loc)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +       unsigned long start, stop;
> +       u8 buf = 0;
> +       int rc;
> +
> +       rc = tpm2_tis_i2c_check_locality(dev, loc);
> +       if (rc >= 0) {
> +               debug("%s: Already have locality\n", __func__);
> +               return loc;  /* We already have the locality */
> +       } else if (rc != -ENOENT) {
> +               debug("%s: Failed to get locality: %d\n", __func__, rc);
> +               return rc;
> +       }
> +
> +       buf = loc;
> +       rc = tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1);
> +       if (rc) {
> +               debug("%s: Failed to write to TPM: %d\n", __func__, rc);
> +               return rc;
> +       }
> +
> +       buf = TPM_ACCESS_REQUEST_USE;
> +       rc = tpm2_tis_i2c_write(dev, TPM_ACCESS, &buf, 1);
> +       if (rc) {
> +               debug("%s: Failed to write to TPM: %d\n", __func__, rc);
> +               return rc;
> +       }
> +
> +       /* Wait for burstcount */
> +       start = get_timer(0);
> +       stop = chip->timeout_a;
> +       do {
> +               rc = tpm2_tis_i2c_check_locality(dev, loc);
> +               if (rc >= 0) {
> +                       debug("%s: Have locality\n", __func__);
> +                       return loc;
> +               } else if (rc != -ENOENT) {
> +                       debug("%s: Failed to get locality: %d\n", __func__, rc);
> +                       return rc;
> +               }
> +               mdelay(TPM_TIMEOUT_MS);
> +       } while (get_timer(start) < stop);
> +       debug("%s: Timeout getting locality: %d\n", __func__, rc);
> +
> +       return rc;
> +}
> +
> +static u8 tpm2_tis_i2c_status(struct udevice *dev)
> +{
> +       /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
> +       u8 buf;
> +
> +       if (tpm2_tis_i2c_read(dev, TPM_STS, &buf, 1) < 0)
> +               return 0;
> +       else
> +               return buf;
> +}
> +
> +static int tpm2_tis_i2c_ready(struct udevice *dev)
> +{
> +       int rc;
> +
> +       /* This causes the current command to be aborted */
> +       u8 buf = TPM_STS_COMMAND_READY;
> +
> +       debug("%s\n", __func__);
> +       rc = tpm2_tis_i2c_write_long(dev, TPM_STS, &buf, 1);
> +       if (rc)
> +               debug("%s: rc=%d\n", __func__, rc);
> +
> +       return rc;
> +}
> +
> +static ssize_t tpm2_tis_i2c_get_burstcount(struct udevice *dev)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +       unsigned long start, stop;
> +       ssize_t burstcnt;
> +       u8 addr, buf[3];
> +
> +       /* Wait for burstcount */
> +       /* XXX: Which timeout value? Spec has 2 answers (c & d) */
> +       start = get_timer(0);
> +       stop = chip->timeout_d;
> +       do {
> +               /* Note: STS is little endian */
> +               addr = TPM_STS + 1;
> +               if (tpm2_tis_i2c_read(dev, addr, buf, 2) < 0)
> +                       burstcnt = 0;
> +               else
> +                       burstcnt = (buf[1] << 8) + buf[0];
> +
> +               if (burstcnt)
> +                       return burstcnt;
> +               mdelay(TPM_TIMEOUT_MS);
> +       } while (get_timer(start) < stop);
> +
> +       return -EBUSY;
> +}
> +
> +static int tpm2_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask,
> +                                     unsigned long timeout, int *status)
> +{
> +       unsigned long start, stop;
> +
> +       /* Check current status */
> +       *status = tpm2_tis_i2c_status(dev);
> +       if ((*status & mask) == mask)
> +               return 0;
> +
> +       start = get_timer(0);
> +       stop = timeout;
> +       do {
> +               mdelay(TPM_TIMEOUT_MS);
> +               *status = tpm2_tis_i2c_status(dev);
> +               if ((*status & mask) == mask)
> +                       return 0;
> +       } while (get_timer(start) < stop);
> +
> +       return -ETIMEDOUT;
> +}
> +
> +static int tpm2_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
> +{
> +       size_t size = 0;
> +       ssize_t burstcnt;
> +       int rc;
> +
> +       while (size < count) {
> +               burstcnt = tpm2_tis_i2c_get_burstcount(dev);
> +
> +               /* burstcount < 0 -> tpm is busy */
> +               if (burstcnt < 0)
> +                       return burstcnt;
> +
> +               /* Limit received data to max left */
> +               if (burstcnt > (count - size))
> +                       burstcnt = count - size;
> +
> +               rc = tpm2_tis_i2c_read(dev, TPM_DATA_FIFO,
> +                                      &(buf[size]), burstcnt);
> +               if (rc == 0)
> +                       size += burstcnt;
> +       }
> +
> +       return size;
> +}
> +
> +static int tpm2_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +       int size = 0;
> +       int status;
> +       unsigned int expected;
> +       int rc;
> +
> +       status = tpm2_tis_i2c_status(dev);
> +       if (status == TPM_STS_COMMAND_READY)
> +               return -EINTR;
> +       if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) !=
> +           (TPM_STS_DATA_AVAIL | TPM_STS_VALID))
> +               return -EAGAIN;
> +
> +       debug("...got it;\n");
> +
> +       /* Read first 10 bytes, including tag, paramsize, and result */
> +       size = tpm2_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
> +       if (size < TPM_HEADER_SIZE) {
> +               debug("Unable to read header\n");
> +               return size < 0 ? size : -EIO;
> +       }
> +
> +       expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
> +       if ((size_t)expected > count || (size_t)expected < TPM_HEADER_SIZE) {
> +               debug("Error size=%x, expected=%x, count=%x\n", size, expected,
> +                     count);
> +               return -ENOSPC;
> +       }
> +
> +       size += tpm2_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
> +                                      expected - TPM_HEADER_SIZE);
> +       if (size < expected) {
> +               debug("Unable to read remainder of result\n");
> +               return -ETIMEDOUT;
> +       }
> +
> +       rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c,
> +                                       &status);
> +       if (rc)
> +               return rc;
> +       if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
> +               debug("Error left over data\n");
> +               return -EIO;
> +       }
> +
> +       return size;
> +}
> +
> +static int tpm2_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +       int rc, status;
> +       size_t burstcnt;
> +       size_t count = 0;
> +       int retry = 0;
> +       u8 sts = TPM_STS_GO;
> +
> +       debug("%s: len=%d\n", __func__, len);
> +       if (len > TPM_DEV_BUFSIZE)
> +               return -E2BIG;  /* Command is too long for our tpm, sorry */
> +
> +       if (tpm2_tis_i2c_request_locality(dev, 0) < 0)
> +               return -EBUSY;
> +
> +       status = tpm2_tis_i2c_status(dev);
> +       if ((status & TPM_STS_COMMAND_READY) == 0) {
> +               rc = tpm2_tis_i2c_ready(dev);
> +               if (rc)
> +                       return rc;
> +               rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
> +                                               chip->timeout_b, &status);
> +               if (rc)
> +                       return rc;
> +       }
> +
> +       burstcnt = tpm2_tis_i2c_get_burstcount(dev);
> +
> +       /* burstcount < 0 -> tpm is busy */
> +       if (burstcnt < 0)
> +               return burstcnt;
> +
> +       while (count < len) {
> +               udelay(300);
> +               if (burstcnt > len - count)
> +                       burstcnt = len - count;
> +
> +#ifdef CONFIG_TPM2_TIS_I2C_BURST_LIMITATION
> +               if (retry && burstcnt > CONFIG_TPM2_TIS_I2C_BURST_LIMITATION_LEN)
> +                       burstcnt = CONFIG_TPM2_TIS_I2C_BURST_LIMITATION_LEN;
> +#endif /* CONFIG_TPM2_TIS_I2C_BURST_LIMITATION */
> +
> +               rc = tpm2_tis_i2c_write(dev, TPM_DATA_FIFO,
> +                                       &(buf[count]), burstcnt);
> +               if (rc == 0)
> +                       count += burstcnt;
> +               else {
> +                       debug("%s: error\n", __func__);
> +                       if (retry++ > 10)
> +                               return -EIO;
> +                       rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_VALID,
> +                                                       chip->timeout_c,
> +                                                       &status);
> +                       if (rc)
> +                               return rc;
> +
> +                       if ((status & TPM_STS_DATA_EXPECT) == 0)
> +                               return -EIO;
> +               }
> +       }
> +
> +       /* Go and do it */
> +       rc = tpm2_tis_i2c_write(dev, TPM_STS, &sts, 1);
> +       if (rc < 0)
> +               return rc;
> +       debug("%s: done, rc=%d\n", __func__, rc);
> +
> +       return len;
> +}
> +
> +static int tpm2_tis_i2c_cleanup(struct udevice *dev)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +
> +       tpm2_tis_i2c_ready(dev);
> +       /*
> +        * The TPM needs some time to clean up here,
> +        * so we sleep rather than keeping the bus busy
> +        */
> +       mdelay(2);
> +       tpm2_tis_i2c_release_locality(dev, chip->locality, 0);
> +
> +       return 0;
> +}
> +
> +static int tpm2_tis_i2c_init(struct udevice *dev)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +       u32 vendor;
> +       u32 expected_did_vid;
> +       int rc;
> +
> +       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;
> +
> +       rc = tpm2_tis_i2c_request_locality(dev, 0);
> +       if (rc < 0)
> +               return rc;
> +
> +       /* Read four bytes from DID_VID register */
> +       if (tpm2_tis_i2c_read(dev, TPM_DID_VID, (uchar *)&vendor, 4) < 0) {
> +               tpm2_tis_i2c_release_locality(dev, 0, 1);
> +               return -EIO;
> +       }
> +
> +       if (chip->chip_type == NPCT75X) {
> +               vendor = be32_to_cpu(vendor);
> +               expected_did_vid = TPM2_TIS_I2C_DID_VID_NPCT75X;
> +       }
> +
> +       if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) {
> +               pr_err("Vendor id did not match! ID was %08x\n", vendor);
> +               return -ENODEV;
> +       }
> +
> +       chip->vend_dev = vendor;
> +       debug("2.0 TPM (chip type %s device-id 0x%X)\n",
> +             chip_name[chip->chip_type], vendor >> 16);
> +
> +       /*
> +        * A timeout query to TPM can be placed here.
> +        * Standard timeout values are used so far
> +        */
> +
> +       return 0;
> +}
> +
> +static int tpm2_tis_i2c_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 = tpm2_tis_i2c_init(dev);
> +       if (rc < 0)
> +               chip->is_open = 0;
> +
> +       return rc;
> +}
> +
> +static int tpm2_tis_i2c_close(struct udevice *dev)
> +{
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +
> +       if (chip->is_open) {
> +               tpm2_tis_i2c_release_locality(dev, chip->locality, 1);
> +               chip->is_open = 0;
> +               chip->vend_dev = 0;
> +       }
> +
> +       return 0;
> +}
> +
> +static int tpm2_tis_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, "2.0 TPM (%s, chip type %s device-id 0x%x)",
> +                       chip->is_open ? "open" : "closed",
> +                       chip_name[chip->chip_type],
> +                       chip->vend_dev >> 16);
> +}
> +
> +static int tpm2_tis_i2c_probe(struct udevice *dev)
> +{
> +       struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
> +       struct tpm_chip *chip = dev_get_priv(dev);
> +
> +       chip->chip_type = dev_get_driver_data(dev);
> +       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;
> +
> +       /* TODO: These need to be checked and tuned */
> +       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;
> +       uc_priv->pcr_count = 24;
> +       uc_priv->pcr_select_min = 3;
> +       uc_priv->version = TPM_V2;
> +
> +       return 0;
> +}
> +
> +static const struct tpm_ops tpm2_tis_i2c_ops = {
> +       .open           = tpm2_tis_i2c_open,
> +       .close          = tpm2_tis_i2c_close,
> +       .get_desc       = tpm2_tis_get_desc,
> +       .send           = tpm2_tis_i2c_send,
> +       .recv           = tpm2_tis_i2c_recv,
> +       .cleanup        = tpm2_tis_i2c_cleanup,
> +};
> +
> +static const struct udevice_id tpm2_tis_i2c_ids[] = {
> +       { .compatible = "nuvoton,npct75x", .data = NPCT75X },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(tpm2_tis_i2c) = {
> +       .name   = "tpm2_tis_i2c",
> +       .id     = UCLASS_TPM,
> +       .of_match = tpm2_tis_i2c_ids,
> +       .ops    = &tpm2_tis_i2c_ops,
> +       .probe  = tpm2_tis_i2c_probe,
> +       .priv_auto_alloc_size = sizeof(struct tpm_chip),
> +};
> --
> 2.27.0
>

Re: [PATCH u-boot v2019.04-aspeed-openbmc 2/5] tpm: Add I2C driver for TPMv2 devices

[Eddie James]

On 5/9/22 21:42, Joel Stanley wrote:
> On Thu, 5 May 2022 at 20:28, Eddie James <eajames@linux.ibm.com> wrote:
>> Add a driver to communicate with TPMv2 chips over I2C, such
>> as the NPCT75X.
>>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
>> ---
>>   drivers/tpm/Kconfig        |   9 +
>>   drivers/tpm/Makefile       |   1 +
>>   drivers/tpm/tpm2_tis_i2c.c | 593 +++++++++++++++++++++++++++++++++++++
>>   3 files changed, 603 insertions(+)
>>   create mode 100644 drivers/tpm/tpm2_tis_i2c.c
>>
>> diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
>> index 94629dffd2..6fd98ac057 100644
>> --- a/drivers/tpm/Kconfig
>> +++ b/drivers/tpm/Kconfig
>> @@ -145,6 +145,15 @@ config TPM2_TIS_SPI
>>            to the device using the standard TPM Interface Specification (TIS)
>>            protocol.
>>
>> +config TPM2_TIS_I2C
>> +       bool "Enable support for TPMv2.x I2C chips"
>> +       depends on TPM_V2 && DM_I2C
>> +       help
>> +         This driver supports TPMv2.x devices connected on the I2C 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 94c337b8ed..220f03253c 100644
>> --- a/drivers/tpm/Makefile
>> +++ b/drivers/tpm/Makefile
>> @@ -12,3 +12,4 @@ obj-$(CONFIG_TPM_ST33ZP24_SPI) += tpm_tis_st33zp24_spi.o
>>
>>   obj-$(CONFIG_TPM2_TIS_SANDBOX) += tpm2_tis_sandbox.o
>>   obj-$(CONFIG_TPM2_TIS_SPI) += tpm2_tis_spi.o
>> +obj-$(CONFIG_TPM2_TIS_I2C) += tpm2_tis_i2c.o
>> diff --git a/drivers/tpm/tpm2_tis_i2c.c b/drivers/tpm/tpm2_tis_i2c.c
>> new file mode 100644
>> index 0000000000..5fab9122e6
>> --- /dev/null
>> +++ b/drivers/tpm/tpm2_tis_i2c.c
>> @@ -0,0 +1,593 @@
>> +// SPDX-License-Identifier: GPL-2.0
> Add:
>
> Copyright 2022 IBM Corp.


Ack.


>
>> +
>> +#include <common.h>
>> +#include <dm.h>
>> +#include <fdtdec.h>
>> +#include <i2c.h>
>> +#include <tpm-v1.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"
>> +
>> +enum i2c_chip_type {
>> +       NPCT75X,
>> +       UNKNOWN,
>> +};
>> +
>> +/* expected value for DIDVID register */
>> +#define TPM2_TIS_I2C_DID_VID_NPCT75X 0x5010FC00L
>> +
>> +static const char * const chip_name[] = {
>> +       [NPCT75X] = "npct75X",
>> +       [UNKNOWN] = "unknown/fallback to npct75X",
>> +};
>> +
>> +#define TPM_LOC_SEL            0x00
>> +#define        TPM_ACCESS              0x04
>> +#define        TPM_STS                 0x18
>> +#define        TPM_DATA_FIFO           0x24
>> +#define        TPM_DID_VID             0x48
>> +
>> +/*
>> + * tpm2_tis_i2c_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 tpm2_tis_i2c_read(struct udevice *dev, u8 addr, u8 *buffer,
>> +                            size_t len)
>> +{
>> +       int rc;
>> +       int count;
>> +
>> +       for (count = 0; count < MAX_COUNT; count++) {
>> +               rc = dm_i2c_read(dev, addr, buffer, len);
>> +               if (rc == 0) {
>> +                       debug("read addr[%02x] len[%u] data[%02x %02x %02x %02x%s]\n", addr, len, len > 0 ? buffer[0] : 0, len > 1 ? buffer[1] : 0, len > 2 ? buffer[2] : 0, len > 3 ? buffer[3] : 0, len > 4 ? " ..." : "");
>> +                       break;  /* break here to skip sleep */
>> +               }
>> +               udelay(SLEEP_DURATION_US);
>> +       }
>> +
>> +       /* Take care of 'guard time' */
>> +       udelay(SLEEP_DURATION_US);
> This will sleep again if the read has reached MAX_COUNT. Could it
> return an error straight away? Or is this a TPM spec thing?
>
> Why are you looping several times? Is that a TPM spec thing?
>
> The kernel does this:
>
> do {
>   ret = i2c_transfer()
>   sleep(GUARD_TIME)
> } while (ret < 0 && count++ < GUARD_TIME)
>
> Which makes more sense.


Yea, I'll switch to that.


>
>> +       if (rc)
>> +               return rc;
>> +
>> +       return 0;
>> +}
>> +
>> +static int tpm2_tis_i2c_write_generic(struct udevice *dev, u8 addr,
>> +                                     const u8 *buffer, size_t len,
>> +                                     unsigned int sleep_time_us, u8 max_count)
>> +{
>> +       int rc = 0;
>> +       int count;
>> +
>> +       for (count = 0; count < max_count; count++) {
>> +               rc = dm_i2c_write(dev, addr, buffer, len);
>> +               if (rc == 0) {
>> +                       debug("write addr[%02x] len[%u] data[%02x %02x %02x %02x%s]\n", addr, len, len > 0 ? buffer[0] : 0, len > 1 ? buffer[1] : 0, len > 2 ? buffer[2] : 0, len > 3 ? buffer[3] : 0, len > 4 ? " ..." : "");
>> +                       break;  /* Success, break to skip sleep */
>> +               }
>> +               udelay(sleep_time_us);
>> +       }
>> +
>> +       /* take care of 'guard time' */
>> +       udelay(sleep_time_us);
>> +       if (rc)
>> +               return rc;
>> +
>> +       return 0;
>> +}
>> +
>> +/*
>> + * tpm2_tis_i2c_write() - write to TPM register
>> + * @addr: register address to write to
>> + * @buffer: containing data to be written
>> + * @len: number of bytes to write
>> + *
>> + * Write len bytes from provided buffer to TPM register (little
>> + * endian format, i.e. buffer[0] is written as first byte).
>> + *
>> + * NOTE: TPM is big-endian for multi-byte values. Multi-byte
>> + * values have to be swapped.
>> + *
>> + * NOTE: use this function instead of the tpm2_tis_i2c_write_generic function.
> Why the extra indirection?
>
> Actually, I see why. This code is a copy of
> drivers/tpm/tpm_tis_infineon.c with some things changed. Can you go
> through the patch and remove things that don't need to be in this
> driver?
>
> The kernel driver is a good reference for things that might be
> required for the spec, vs coding decisions made by the infineon driver
> author.


Sure, I'll clean it up.

Thanks for the review!


>
>
>> + *
>> + * Return -EIO on error, 0 on success
>> + */
>> +static int tpm2_tis_i2c_write(struct udevice *dev, u8 addr, const u8 *buffer,
>> +                             size_t len)
>> +{
>> +       return tpm2_tis_i2c_write_generic(dev, addr, buffer, len,
>> +                                         SLEEP_DURATION_US, MAX_COUNT);
>> +}
>> +
>> +/*
>> + * This function is needed especially for the cleanup situation after
>> + * sending TPM_READY
>> + */
>> +static int tpm2_tis_i2c_write_long(struct udevice *dev, u8 addr, u8 *buffer,
>> +                                  size_t len)
>> +{
>> +       return tpm2_tis_i2c_write_generic(dev, addr, buffer, len,
>> +                                         SLEEP_DURATION_LONG_US,
>> +                                         MAX_COUNT_LONG);
>> +}
>> +
>> +static int tpm2_tis_i2c_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 rc;
>> +
>> +       buf = loc;
>> +       rc = tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1);
>> +       if (rc < 0)
>> +               return rc;
>> +
>> +       rc = tpm2_tis_i2c_read(dev, TPM_ACCESS, &buf, 1);
>> +       if (rc < 0)
>> +               return rc;
>> +
>> +       if ((buf & mask) == mask) {
>> +               chip->locality = loc;
>> +               return loc;
>> +       }
>> +
>> +       return -ENOENT;
>> +}
>> +
>> +static void tpm2_tis_i2c_release_locality(struct udevice *dev, int loc,
>> +                                        int force)
>> +{
>> +       const u8 mask = TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID;
>> +       u8 buf;
>> +
>> +       buf = loc;
>> +       if (tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1) < 0)
>> +               return;
>> +
>> +       if (tpm2_tis_i2c_read(dev, TPM_ACCESS, &buf, 1) < 0)
>> +               return;
>> +
>> +       if (force || (buf & mask) == mask) {
>> +               buf = TPM_ACCESS_ACTIVE_LOCALITY;
>> +               tpm2_tis_i2c_write(dev, TPM_ACCESS, &buf, 1);
>> +       }
>> +}
>> +
>> +static int tpm2_tis_i2c_request_locality(struct udevice *dev, int loc)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +       unsigned long start, stop;
>> +       u8 buf = 0;
>> +       int rc;
>> +
>> +       rc = tpm2_tis_i2c_check_locality(dev, loc);
>> +       if (rc >= 0) {
>> +               debug("%s: Already have locality\n", __func__);
>> +               return loc;  /* We already have the locality */
>> +       } else if (rc != -ENOENT) {
>> +               debug("%s: Failed to get locality: %d\n", __func__, rc);
>> +               return rc;
>> +       }
>> +
>> +       buf = loc;
>> +       rc = tpm2_tis_i2c_write(dev, TPM_LOC_SEL, &buf, 1);
>> +       if (rc) {
>> +               debug("%s: Failed to write to TPM: %d\n", __func__, rc);
>> +               return rc;
>> +       }
>> +
>> +       buf = TPM_ACCESS_REQUEST_USE;
>> +       rc = tpm2_tis_i2c_write(dev, TPM_ACCESS, &buf, 1);
>> +       if (rc) {
>> +               debug("%s: Failed to write to TPM: %d\n", __func__, rc);
>> +               return rc;
>> +       }
>> +
>> +       /* Wait for burstcount */
>> +       start = get_timer(0);
>> +       stop = chip->timeout_a;
>> +       do {
>> +               rc = tpm2_tis_i2c_check_locality(dev, loc);
>> +               if (rc >= 0) {
>> +                       debug("%s: Have locality\n", __func__);
>> +                       return loc;
>> +               } else if (rc != -ENOENT) {
>> +                       debug("%s: Failed to get locality: %d\n", __func__, rc);
>> +                       return rc;
>> +               }
>> +               mdelay(TPM_TIMEOUT_MS);
>> +       } while (get_timer(start) < stop);
>> +       debug("%s: Timeout getting locality: %d\n", __func__, rc);
>> +
>> +       return rc;
>> +}
>> +
>> +static u8 tpm2_tis_i2c_status(struct udevice *dev)
>> +{
>> +       /* NOTE: Since i2c read may fail, return 0 in this case --> time-out */
>> +       u8 buf;
>> +
>> +       if (tpm2_tis_i2c_read(dev, TPM_STS, &buf, 1) < 0)
>> +               return 0;
>> +       else
>> +               return buf;
>> +}
>> +
>> +static int tpm2_tis_i2c_ready(struct udevice *dev)
>> +{
>> +       int rc;
>> +
>> +       /* This causes the current command to be aborted */
>> +       u8 buf = TPM_STS_COMMAND_READY;
>> +
>> +       debug("%s\n", __func__);
>> +       rc = tpm2_tis_i2c_write_long(dev, TPM_STS, &buf, 1);
>> +       if (rc)
>> +               debug("%s: rc=%d\n", __func__, rc);
>> +
>> +       return rc;
>> +}
>> +
>> +static ssize_t tpm2_tis_i2c_get_burstcount(struct udevice *dev)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +       unsigned long start, stop;
>> +       ssize_t burstcnt;
>> +       u8 addr, buf[3];
>> +
>> +       /* Wait for burstcount */
>> +       /* XXX: Which timeout value? Spec has 2 answers (c & d) */
>> +       start = get_timer(0);
>> +       stop = chip->timeout_d;
>> +       do {
>> +               /* Note: STS is little endian */
>> +               addr = TPM_STS + 1;
>> +               if (tpm2_tis_i2c_read(dev, addr, buf, 2) < 0)
>> +                       burstcnt = 0;
>> +               else
>> +                       burstcnt = (buf[1] << 8) + buf[0];
>> +
>> +               if (burstcnt)
>> +                       return burstcnt;
>> +               mdelay(TPM_TIMEOUT_MS);
>> +       } while (get_timer(start) < stop);
>> +
>> +       return -EBUSY;
>> +}
>> +
>> +static int tpm2_tis_i2c_wait_for_stat(struct udevice *dev, u8 mask,
>> +                                     unsigned long timeout, int *status)
>> +{
>> +       unsigned long start, stop;
>> +
>> +       /* Check current status */
>> +       *status = tpm2_tis_i2c_status(dev);
>> +       if ((*status & mask) == mask)
>> +               return 0;
>> +
>> +       start = get_timer(0);
>> +       stop = timeout;
>> +       do {
>> +               mdelay(TPM_TIMEOUT_MS);
>> +               *status = tpm2_tis_i2c_status(dev);
>> +               if ((*status & mask) == mask)
>> +                       return 0;
>> +       } while (get_timer(start) < stop);
>> +
>> +       return -ETIMEDOUT;
>> +}
>> +
>> +static int tpm2_tis_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
>> +{
>> +       size_t size = 0;
>> +       ssize_t burstcnt;
>> +       int rc;
>> +
>> +       while (size < count) {
>> +               burstcnt = tpm2_tis_i2c_get_burstcount(dev);
>> +
>> +               /* burstcount < 0 -> tpm is busy */
>> +               if (burstcnt < 0)
>> +                       return burstcnt;
>> +
>> +               /* Limit received data to max left */
>> +               if (burstcnt > (count - size))
>> +                       burstcnt = count - size;
>> +
>> +               rc = tpm2_tis_i2c_read(dev, TPM_DATA_FIFO,
>> +                                      &(buf[size]), burstcnt);
>> +               if (rc == 0)
>> +                       size += burstcnt;
>> +       }
>> +
>> +       return size;
>> +}
>> +
>> +static int tpm2_tis_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +       int size = 0;
>> +       int status;
>> +       unsigned int expected;
>> +       int rc;
>> +
>> +       status = tpm2_tis_i2c_status(dev);
>> +       if (status == TPM_STS_COMMAND_READY)
>> +               return -EINTR;
>> +       if ((status & (TPM_STS_DATA_AVAIL | TPM_STS_VALID)) !=
>> +           (TPM_STS_DATA_AVAIL | TPM_STS_VALID))
>> +               return -EAGAIN;
>> +
>> +       debug("...got it;\n");
>> +
>> +       /* Read first 10 bytes, including tag, paramsize, and result */
>> +       size = tpm2_tis_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
>> +       if (size < TPM_HEADER_SIZE) {
>> +               debug("Unable to read header\n");
>> +               return size < 0 ? size : -EIO;
>> +       }
>> +
>> +       expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
>> +       if ((size_t)expected > count || (size_t)expected < TPM_HEADER_SIZE) {
>> +               debug("Error size=%x, expected=%x, count=%x\n", size, expected,
>> +                     count);
>> +               return -ENOSPC;
>> +       }
>> +
>> +       size += tpm2_tis_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
>> +                                      expected - TPM_HEADER_SIZE);
>> +       if (size < expected) {
>> +               debug("Unable to read remainder of result\n");
>> +               return -ETIMEDOUT;
>> +       }
>> +
>> +       rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_VALID, chip->timeout_c,
>> +                                       &status);
>> +       if (rc)
>> +               return rc;
>> +       if (status & TPM_STS_DATA_AVAIL) {  /* Retry? */
>> +               debug("Error left over data\n");
>> +               return -EIO;
>> +       }
>> +
>> +       return size;
>> +}
>> +
>> +static int tpm2_tis_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +       int rc, status;
>> +       size_t burstcnt;
>> +       size_t count = 0;
>> +       int retry = 0;
>> +       u8 sts = TPM_STS_GO;
>> +
>> +       debug("%s: len=%d\n", __func__, len);
>> +       if (len > TPM_DEV_BUFSIZE)
>> +               return -E2BIG;  /* Command is too long for our tpm, sorry */
>> +
>> +       if (tpm2_tis_i2c_request_locality(dev, 0) < 0)
>> +               return -EBUSY;
>> +
>> +       status = tpm2_tis_i2c_status(dev);
>> +       if ((status & TPM_STS_COMMAND_READY) == 0) {
>> +               rc = tpm2_tis_i2c_ready(dev);
>> +               if (rc)
>> +                       return rc;
>> +               rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
>> +                                               chip->timeout_b, &status);
>> +               if (rc)
>> +                       return rc;
>> +       }
>> +
>> +       burstcnt = tpm2_tis_i2c_get_burstcount(dev);
>> +
>> +       /* burstcount < 0 -> tpm is busy */
>> +       if (burstcnt < 0)
>> +               return burstcnt;
>> +
>> +       while (count < len) {
>> +               udelay(300);
>> +               if (burstcnt > len - count)
>> +                       burstcnt = len - count;
>> +
>> +#ifdef CONFIG_TPM2_TIS_I2C_BURST_LIMITATION
>> +               if (retry && burstcnt > CONFIG_TPM2_TIS_I2C_BURST_LIMITATION_LEN)
>> +                       burstcnt = CONFIG_TPM2_TIS_I2C_BURST_LIMITATION_LEN;
>> +#endif /* CONFIG_TPM2_TIS_I2C_BURST_LIMITATION */
>> +
>> +               rc = tpm2_tis_i2c_write(dev, TPM_DATA_FIFO,
>> +                                       &(buf[count]), burstcnt);
>> +               if (rc == 0)
>> +                       count += burstcnt;
>> +               else {
>> +                       debug("%s: error\n", __func__);
>> +                       if (retry++ > 10)
>> +                               return -EIO;
>> +                       rc = tpm2_tis_i2c_wait_for_stat(dev, TPM_STS_VALID,
>> +                                                       chip->timeout_c,
>> +                                                       &status);
>> +                       if (rc)
>> +                               return rc;
>> +
>> +                       if ((status & TPM_STS_DATA_EXPECT) == 0)
>> +                               return -EIO;
>> +               }
>> +       }
>> +
>> +       /* Go and do it */
>> +       rc = tpm2_tis_i2c_write(dev, TPM_STS, &sts, 1);
>> +       if (rc < 0)
>> +               return rc;
>> +       debug("%s: done, rc=%d\n", __func__, rc);
>> +
>> +       return len;
>> +}
>> +
>> +static int tpm2_tis_i2c_cleanup(struct udevice *dev)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +
>> +       tpm2_tis_i2c_ready(dev);
>> +       /*
>> +        * The TPM needs some time to clean up here,
>> +        * so we sleep rather than keeping the bus busy
>> +        */
>> +       mdelay(2);
>> +       tpm2_tis_i2c_release_locality(dev, chip->locality, 0);
>> +
>> +       return 0;
>> +}
>> +
>> +static int tpm2_tis_i2c_init(struct udevice *dev)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +       u32 vendor;
>> +       u32 expected_did_vid;
>> +       int rc;
>> +
>> +       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;
>> +
>> +       rc = tpm2_tis_i2c_request_locality(dev, 0);
>> +       if (rc < 0)
>> +               return rc;
>> +
>> +       /* Read four bytes from DID_VID register */
>> +       if (tpm2_tis_i2c_read(dev, TPM_DID_VID, (uchar *)&vendor, 4) < 0) {
>> +               tpm2_tis_i2c_release_locality(dev, 0, 1);
>> +               return -EIO;
>> +       }
>> +
>> +       if (chip->chip_type == NPCT75X) {
>> +               vendor = be32_to_cpu(vendor);
>> +               expected_did_vid = TPM2_TIS_I2C_DID_VID_NPCT75X;
>> +       }
>> +
>> +       if (chip->chip_type != UNKNOWN && vendor != expected_did_vid) {
>> +               pr_err("Vendor id did not match! ID was %08x\n", vendor);
>> +               return -ENODEV;
>> +       }
>> +
>> +       chip->vend_dev = vendor;
>> +       debug("2.0 TPM (chip type %s device-id 0x%X)\n",
>> +             chip_name[chip->chip_type], vendor >> 16);
>> +
>> +       /*
>> +        * A timeout query to TPM can be placed here.
>> +        * Standard timeout values are used so far
>> +        */
>> +
>> +       return 0;
>> +}
>> +
>> +static int tpm2_tis_i2c_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 = tpm2_tis_i2c_init(dev);
>> +       if (rc < 0)
>> +               chip->is_open = 0;
>> +
>> +       return rc;
>> +}
>> +
>> +static int tpm2_tis_i2c_close(struct udevice *dev)
>> +{
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +
>> +       if (chip->is_open) {
>> +               tpm2_tis_i2c_release_locality(dev, chip->locality, 1);
>> +               chip->is_open = 0;
>> +               chip->vend_dev = 0;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int tpm2_tis_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, "2.0 TPM (%s, chip type %s device-id 0x%x)",
>> +                       chip->is_open ? "open" : "closed",
>> +                       chip_name[chip->chip_type],
>> +                       chip->vend_dev >> 16);
>> +}
>> +
>> +static int tpm2_tis_i2c_probe(struct udevice *dev)
>> +{
>> +       struct tpm_chip_priv *uc_priv = dev_get_uclass_priv(dev);
>> +       struct tpm_chip *chip = dev_get_priv(dev);
>> +
>> +       chip->chip_type = dev_get_driver_data(dev);
>> +       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;
>> +
>> +       /* TODO: These need to be checked and tuned */
>> +       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;
>> +       uc_priv->pcr_count = 24;
>> +       uc_priv->pcr_select_min = 3;
>> +       uc_priv->version = TPM_V2;
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct tpm_ops tpm2_tis_i2c_ops = {
>> +       .open           = tpm2_tis_i2c_open,
>> +       .close          = tpm2_tis_i2c_close,
>> +       .get_desc       = tpm2_tis_get_desc,
>> +       .send           = tpm2_tis_i2c_send,
>> +       .recv           = tpm2_tis_i2c_recv,
>> +       .cleanup        = tpm2_tis_i2c_cleanup,
>> +};
>> +
>> +static const struct udevice_id tpm2_tis_i2c_ids[] = {
>> +       { .compatible = "nuvoton,npct75x", .data = NPCT75X },
>> +       { }
>> +};
>> +
>> +U_BOOT_DRIVER(tpm2_tis_i2c) = {
>> +       .name   = "tpm2_tis_i2c",
>> +       .id     = UCLASS_TPM,
>> +       .of_match = tpm2_tis_i2c_ids,
>> +       .ops    = &tpm2_tis_i2c_ops,
>> +       .probe  = tpm2_tis_i2c_probe,
>> +       .priv_auto_alloc_size = sizeof(struct tpm_chip),
>> +};
>> --
>> 2.27.0
>>

[PATCH u-boot v2019.04-aspeed-openbmc 3/5] arm: dts: ast2600-rainier: Add NPCT75X TPM

[Eddie James]

Add the TPM device on I2C bus 12.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 arch/arm/dts/ast2600-rainier.dts | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
index 8a44fd8a0a..aa91b12ed3 100755
--- a/arch/arm/dts/ast2600-rainier.dts
+++ b/arch/arm/dts/ast2600-rainier.dts
@@ -106,12 +106,14 @@
 
 &gpio0 {
 	u-boot,dm-pre-reloc;
+};
+
+&i2c12 {
+	status = "okay";
 
-	tpm_reset {
-		u-boot,dm-pre-reloc;
-		gpio-hog;
-		output-high;
-		gpios = <ASPEED_GPIO(R, 0) GPIO_ACTIVE_HIGH>;
+	tpm@2e {
+		compatible = "nuvoton,npct75x";
+		reg = <0x2e>;
 	};
 };
 
-- 
2.27.0

Re: [PATCH u-boot v2019.04-aspeed-openbmc 3/5] arm: dts: ast2600-rainier: Add NPCT75X TPM

[Joel Stanley]

On Thu, 5 May 2022 at 20:28, Eddie James <eajames@linux.ibm.com> wrote:
>
> Add the TPM device on I2C bus 12.

What happens when a board doesn't have a TPM attached to this bus?

>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> ---
>  arch/arm/dts/ast2600-rainier.dts | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/dts/ast2600-rainier.dts b/arch/arm/dts/ast2600-rainier.dts
> index 8a44fd8a0a..aa91b12ed3 100755
> --- a/arch/arm/dts/ast2600-rainier.dts
> +++ b/arch/arm/dts/ast2600-rainier.dts
> @@ -106,12 +106,14 @@
>
>  &gpio0 {
>         u-boot,dm-pre-reloc;
> +};
> +
> +&i2c12 {
> +       status = "okay";
>
> -       tpm_reset {
> -               u-boot,dm-pre-reloc;
> -               gpio-hog;
> -               output-high;
> -               gpios = <ASPEED_GPIO(R, 0) GPIO_ACTIVE_HIGH>;
> +       tpm@2e {
> +               compatible = "nuvoton,npct75x";
> +               reg = <0x2e>;
>         };
>  };
>
> --
> 2.27.0
>

[PATCH u-boot v2019.04-aspeed-openbmc 4/5] configs: ast2600_openbmc_spl_emmc: Enable TPMv2 over I2C

[Eddie James]

Enable the I2C TPM communication driver to talk to TPM device
over I2C.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 configs/ast2600_openbmc_spl_emmc_defconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig b/configs/ast2600_openbmc_spl_emmc_defconfig
index 4ea0f34148..3bb44280c7 100644
--- a/configs/ast2600_openbmc_spl_emmc_defconfig
+++ b/configs/ast2600_openbmc_spl_emmc_defconfig
@@ -132,5 +132,5 @@ CONFIG_WDT=y
 CONFIG_USE_TINY_PRINTF=y
 CONFIG_SPL_TINY_MEMSET=y
 CONFIG_TPM=y
-CONFIG_SPL_TPM=y
+CONFIG_TPM2_TIS_I2C=y
 # CONFIG_EFI_LOADER is not set
-- 
2.27.0

[PATCH u-boot v2019.04-aspeed-openbmc 5/5] aspeed: Add board_late_init to write TPM

[Eddie James]

If there is a TPM in the devicetree, use board_late_init to
extend PCR0 with some invalid digest. The purpose of this is to
prevent later undesired usage of the TPM.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 board/aspeed/evb_ast2600/evb_ast2600.c     | 34 ++++++++++++++++++++++
 configs/ast2600_openbmc_spl_emmc_defconfig |  1 +
 2 files changed, 35 insertions(+)

diff --git a/board/aspeed/evb_ast2600/evb_ast2600.c b/board/aspeed/evb_ast2600/evb_ast2600.c
index 72ecb18c15..e11fc6973d 100644
--- a/board/aspeed/evb_ast2600/evb_ast2600.c
+++ b/board/aspeed/evb_ast2600/evb_ast2600.c
@@ -3,6 +3,11 @@
  * Copyright (C) ASPEED Technology Inc.
  */
 #include <common.h>
+#if defined(CONFIG_TPM_V2)
+#include <dm/uclass.h>
+#include <tpm-common.h>
+#include <tpm-v2.h>
+#endif
 #include <asm/io.h>
 
 #define SCU_BASE	0x1e6e2000
@@ -122,6 +127,35 @@ static void __maybe_unused espi_init(void)
 	writel(reg, ESPI_BASE + 0x000);
 }
 
+__weak int board_late_init(void)
+{
+#if defined(CONFIG_TPM_V2)
+	int rc;
+	struct udevice *dev;
+	unsigned char digest[32] = {
+		0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, 0x01,
+		0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
+		0xa0, 0xb1, 0xc2, 0xd3, 0xe4, 0xf5, 0x06, 0x17,
+		0x28, 0x39, 0x4a, 0x5b, 0x6c, 0x7d, 0x8e, 0x9f
+	};
+
+	rc = uclass_first_device_err(UCLASS_TPM, &dev);
+	if (rc)
+		return 0;
+
+	rc = tpm_init(dev);
+	if (rc)
+		return 0;
+
+	rc = tpm2_startup(dev, TPM2_SU_CLEAR);
+	if (rc)
+		return 0;
+
+	tpm2_pcr_extend(dev, 0, digest);
+#endif
+	return 0;
+}
+
 int board_early_init_f(void)
 {
 #if 0
diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig b/configs/ast2600_openbmc_spl_emmc_defconfig
index 3bb44280c7..b506bc5e55 100644
--- a/configs/ast2600_openbmc_spl_emmc_defconfig
+++ b/configs/ast2600_openbmc_spl_emmc_defconfig
@@ -39,6 +39,7 @@ CONFIG_SYS_CONSOLE_ENV_OVERWRITE=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_ARCH_EARLY_INIT_R=y
 CONFIG_BOARD_EARLY_INIT_F=y
+CONFIG_BOARD_LATE_INIT=y
 CONFIG_SPL_BOARD_INIT=y
 # CONFIG_SPL_LEGACY_IMAGE_SUPPORT is not set
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
-- 
2.27.0

Re: [PATCH u-boot v2019.04-aspeed-openbmc 5/5] aspeed: Add board_late_init to write TPM

[Joel Stanley]

On Thu, 5 May 2022 at 20:28, Eddie James <eajames@linux.ibm.com> wrote:
>
> If there is a TPM in the devicetree, use board_late_init to
> extend PCR0 with some invalid digest. The purpose of this is to
> prevent later undesired usage of the TPM.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>

I think we will need a board_late_init for our platform, as others may
use the TPM and not want to poison it.

> ---
>  board/aspeed/evb_ast2600/evb_ast2600.c     | 34 ++++++++++++++++++++++
>  configs/ast2600_openbmc_spl_emmc_defconfig |  1 +
>  2 files changed, 35 insertions(+)
>
> diff --git a/board/aspeed/evb_ast2600/evb_ast2600.c b/board/aspeed/evb_ast2600/evb_ast2600.c
> index 72ecb18c15..e11fc6973d 100644
> --- a/board/aspeed/evb_ast2600/evb_ast2600.c
> +++ b/board/aspeed/evb_ast2600/evb_ast2600.c
> @@ -3,6 +3,11 @@
>   * Copyright (C) ASPEED Technology Inc.
>   */
>  #include <common.h>
> +#if defined(CONFIG_TPM_V2)
> +#include <dm/uclass.h>
> +#include <tpm-common.h>
> +#include <tpm-v2.h>
> +#endif
>  #include <asm/io.h>
>
>  #define SCU_BASE       0x1e6e2000
> @@ -122,6 +127,35 @@ static void __maybe_unused espi_init(void)
>         writel(reg, ESPI_BASE + 0x000);
>  }
>
> +__weak int board_late_init(void)
> +{
> +#if defined(CONFIG_TPM_V2)
> +       int rc;
> +       struct udevice *dev;
> +       unsigned char digest[32] = {
> +               0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, 0x01,
> +               0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
> +               0xa0, 0xb1, 0xc2, 0xd3, 0xe4, 0xf5, 0x06, 0x17,
> +               0x28, 0x39, 0x4a, 0x5b, 0x6c, 0x7d, 0x8e, 0x9f
> +       };

Add a comment for how this was created.

> +
> +       rc = uclass_first_device_err(UCLASS_TPM, &dev);
> +       if (rc)
> +               return 0;
> +
> +       rc = tpm_init(dev);
> +       if (rc)
> +               return 0;
> +
> +       rc = tpm2_startup(dev, TPM2_SU_CLEAR);
> +       if (rc)
> +               return 0;
> +
> +       tpm2_pcr_extend(dev, 0, digest);
> +#endif
> +       return 0;
> +}
> +
>  int board_early_init_f(void)
>  {
>  #if 0
> diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig b/configs/ast2600_openbmc_spl_emmc_defconfig
> index 3bb44280c7..b506bc5e55 100644
> --- a/configs/ast2600_openbmc_spl_emmc_defconfig
> +++ b/configs/ast2600_openbmc_spl_emmc_defconfig
> @@ -39,6 +39,7 @@ CONFIG_SYS_CONSOLE_ENV_OVERWRITE=y
>  CONFIG_DISPLAY_BOARDINFO_LATE=y
>  CONFIG_ARCH_EARLY_INIT_R=y
>  CONFIG_BOARD_EARLY_INIT_F=y
> +CONFIG_BOARD_LATE_INIT=y
>  CONFIG_SPL_BOARD_INIT=y
>  # CONFIG_SPL_LEGACY_IMAGE_SUPPORT is not set
>  CONFIG_SPL_SYS_MALLOC_SIMPLE=y
> --
> 2.27.0
>

Re: [PATCH u-boot v2019.04-aspeed-openbmc 5/5] aspeed: Add board_late_init to write TPM

[Eddie James]

On 5/9/22 21:44, Joel Stanley wrote:
> On Thu, 5 May 2022 at 20:28, Eddie James <eajames@linux.ibm.com> wrote:
>> If there is a TPM in the devicetree, use board_late_init to
>> extend PCR0 with some invalid digest. The purpose of this is to
>> prevent later undesired usage of the TPM.
>>
>> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> I think we will need a board_late_init for our platform, as others may
> use the TPM and not want to poison it.


Yea I'll give that a go. I tried it and I had a brief fight with the 
config and build and gave up :)


>
>> ---
>>   board/aspeed/evb_ast2600/evb_ast2600.c     | 34 ++++++++++++++++++++++
>>   configs/ast2600_openbmc_spl_emmc_defconfig |  1 +
>>   2 files changed, 35 insertions(+)
>>
>> diff --git a/board/aspeed/evb_ast2600/evb_ast2600.c b/board/aspeed/evb_ast2600/evb_ast2600.c
>> index 72ecb18c15..e11fc6973d 100644
>> --- a/board/aspeed/evb_ast2600/evb_ast2600.c
>> +++ b/board/aspeed/evb_ast2600/evb_ast2600.c
>> @@ -3,6 +3,11 @@
>>    * Copyright (C) ASPEED Technology Inc.
>>    */
>>   #include <common.h>
>> +#if defined(CONFIG_TPM_V2)
>> +#include <dm/uclass.h>
>> +#include <tpm-common.h>
>> +#include <tpm-v2.h>
>> +#endif
>>   #include <asm/io.h>
>>
>>   #define SCU_BASE       0x1e6e2000
>> @@ -122,6 +127,35 @@ static void __maybe_unused espi_init(void)
>>          writel(reg, ESPI_BASE + 0x000);
>>   }
>>
>> +__weak int board_late_init(void)
>> +{
>> +#if defined(CONFIG_TPM_V2)
>> +       int rc;
>> +       struct udevice *dev;
>> +       unsigned char digest[32] = {
>> +               0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, 0x01,
>> +               0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
>> +               0xa0, 0xb1, 0xc2, 0xd3, 0xe4, 0xf5, 0x06, 0x17,
>> +               0x28, 0x39, 0x4a, 0x5b, 0x6c, 0x7d, 0x8e, 0x9f
>> +       };
> Add a comment for how this was created.
>
>> +
>> +       rc = uclass_first_device_err(UCLASS_TPM, &dev);
>> +       if (rc)
>> +               return 0;
>> +
>> +       rc = tpm_init(dev);
>> +       if (rc)
>> +               return 0;
>> +
>> +       rc = tpm2_startup(dev, TPM2_SU_CLEAR);
>> +       if (rc)
>> +               return 0;
>> +
>> +       tpm2_pcr_extend(dev, 0, digest);
>> +#endif
>> +       return 0;
>> +}
>> +
>>   int board_early_init_f(void)
>>   {
>>   #if 0
>> diff --git a/configs/ast2600_openbmc_spl_emmc_defconfig b/configs/ast2600_openbmc_spl_emmc_defconfig
>> index 3bb44280c7..b506bc5e55 100644
>> --- a/configs/ast2600_openbmc_spl_emmc_defconfig
>> +++ b/configs/ast2600_openbmc_spl_emmc_defconfig
>> @@ -39,6 +39,7 @@ CONFIG_SYS_CONSOLE_ENV_OVERWRITE=y
>>   CONFIG_DISPLAY_BOARDINFO_LATE=y
>>   CONFIG_ARCH_EARLY_INIT_R=y
>>   CONFIG_BOARD_EARLY_INIT_F=y
>> +CONFIG_BOARD_LATE_INIT=y
>>   CONFIG_SPL_BOARD_INIT=y
>>   # CONFIG_SPL_LEGACY_IMAGE_SUPPORT is not set
>>   CONFIG_SPL_SYS_MALLOC_SIMPLE=y
>> --
>> 2.27.0
>>