[PATCH v7 0/7] Add tpm i2c ptp driver

[PATCH v7 0/7] Add tpm i2c ptp driver

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

This patch set adds support for TPM devices that implement the I2C.
Interface defined by TCG PTP specification:
https://trustedcomputinggroup.org/wp-content/uploads/TCG_PC_Client_Platform_TPM_Profile_PTP_2.0_r1.03_v22.pdf

The driver was tested on Raspberry-Pie 3, using Nuvoton NPCT75X TPM.

Interrupts are not implemented yet, preparing it for the next patch.
This patch is based on initial work by oshri Alkoby, Alexander Steffen and Christophe Ricard

Changes since version 1:
-"char:tpm:Add check_data handle to tpm_tis_phy_ops in order to check data integrity"
        - Fixed and extended commit description.
        - Fixed an issue regarding handling max retries.
-"dt-bindings: tpm: Add YAML schema for TPM TIS I2C options":
        -Converted "tpm_tis_i2c.txt" to "tpm-tis-i2c.yaml".
        - Renamed "tpm_tis-i2c" to "tpm-tis-i2c".
        - Removed interrupts properties.
-"char: tpm: add tpm_tis_i2c driver"
        - Replaced "tpm_tis-i2c" with "tpm-tis-i2c" in "tpm_tis_i2c.c".
Addressed comments from:
 - Jarkko Sakkinen: https://patchwork.kernel.org/patch/11236257/
 - Rob Herring: https://patchwork.kernel.org/patch/11236253/

Changes since version 2:
- Added 2 new commits with improvements suggested by Benoit Houyere.
        -"Fix expected bit handling and send all bytes in one shot without last byte in exception"
        -"Handle an exception for TPM Firmware Update mode."
- Updated patch to latest v5.5
-"dt-bindings: tpm: Add YAML schema for TPM TIS I2C options"
        - Added "interrupts" and "crc-checksum" to properties.
        - Updated binding description and commit info.
-"char: tpm: add tpm_tis_i2c driver" (suggested by Benoit Houyere)
        - Added repeat I2C frame after NACK.
        - Checksum I2C feature activation in DTS file configuration.
Addressed comments from:
 - Rob Herring: https://lore.kernel.org/patchwork/patch/1161287/

Changes since version 3:
- Updated patch to latest v5.6
- Updated commits headlines and development credit format by Jarkko Sakkinen suggestion
-"tpm: tpm_tis: Make implementation of read16 read32 write32 optional"
        - Updated commit description.
-"dt-bindings: tpm: Add YAML schema for TPM TIS I2C options"
        - Fixed 'make dt_binding_check' errors on YAML file.
        - Removed interrupts from required and examples since there is no use for them in current patch.
Addressed comments from:
 - Jarkko Sakkinen: https://lore.kernel.org/patchwork/patch/1192101/
 - Rob Herring: https://lore.kernel.org/patchwork/patch/1192099/

Changes since version 4:
-"tpm: tpm_tis: Make implementation of read16 read32 write32 optional"
        -Added a "Reviewed-by" tag:
-"tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops in order to check data integrity"
        -Fixed credit typos.
-"tpm: tpm_tis: rewrite "tpm_tis_req_canceled()""
        -Added fixes tag and removed changes for STM.
-"tpm: tpm_tis: Fix expected bit handling and send all bytes in one shot without last byte in exception"
        -Fixed typos, edited description to be clearer, and added a "Suggested-by" tag.
-"tpm: Handle an exception for TPM Firmware Update mode."
        -Added a "Suggested-by" tag.
-"dt-bindings: tpm: Add YAML schema for TPM TIS I2C options"
        -Fixed 'make dt_binding_check' errors.
-"tpm: tpm_tis: add tpm_tis_i2c driver"
        -Added tested-by tag by Eddie James.
        -Fixed indent in Kconfig file.
        -Fixed 'MODULE_DESCRIPTION'.
Addressed comments from:
 - Jarkko Sakkinen: https://patchwork.kernel.org/patch/11467645/
                https://patchwork.kernel.org/patch/11467655/
                https://patchwork.kernel.org/patch/11467643/
                https://patchwork.kernel.org/patch/11467659/
                https://patchwork.kernel.org/patch/11467651/
 - Rob Herring: https://patchwork.kernel.org/patch/11467653/
 - Randy Dunlap: https://patchwork.kernel.org/patch/11467651/
 - Eddie James: https://lore.kernel.org/patchwork/patch/1192104/

Changes since version 5:
-"tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops"
        -Updated short description and fixed long description to be more clear.
Addressed comments from:
 - Jarkko Sakkinen: https://lkml.org/lkml/2020/4/6/748

Changes since version 6:
-"tpm: tpm_tis: Make implementation of read16, read32 and write32 optional"
        -Fixed short description.
        -Fixed long description proofreading issues.
-"tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops"
        -Fixed long description by Jarkko comments and proofreading issues.
        -Replaced "check_data" with verify_data_integrity".
        -New line before return statement.
-"tpm: tpm_tis: rewrite "tpm_tis_req_canceled()"
        -Fixed line over 80 characters.
        -Fixed long description proofreading issues.
-" tpm: tpm_tis: Fix expected bit handling and send all bytes in one shot"
        -Fixed long description proofreading issues.
-"dt-bindings: tpm: Add YAML schema for TPM TIS I2C option"
        -Replaced "tpm-tis-i2c@2e" with "tpm_tis@2e".
        -Fixed CRC_Checksum description.
-"tpm: tpm_tis: add tpm_tis_i2c driver"
        -Replaced "depends on CRC_CCIT" with "select CRC_CCIT".
        -Added tested-by tag by Joel Stanley.
        -Fixed checkpatch.pl warnings.
Addressed comments from:
 - Jarkko Sakkinen:
        https://lore.kernel.org/patchwork/patch/1221336/
        https://lore.kernel.org/patchwork/patch/1221337/
        https://lore.kernel.org/patchwork/patch/1221339/
 - Joel Stanley:
        https://lore.kernel.org/patchwork/patch/1220543/
 - Rob Herring:
        https://lore.kernel.org/patchwork/patch/1221334/

Amir Mizinski (7):
  tpm: tpm_tis: Make implementation of read16, read32 and write32
    optional
  tpm: tpm_tis: Add verify_data_integrity handle toy tpm_tis_phy_ops
  tpm: tpm_tis: Rewrite "tpm_tis_req_canceled()"
  tpm: tpm_tis: Fix expected bit handling and send all bytes in one shot
    without last byte in exception
  tpm: Handle an exception for TPM Firmware Update mode.
  tpm: Add YAML schema for TPM TIS I2C options
  tpm: tpm_tis: add tpm_tis_i2c driver

 .../bindings/security/tpm/tpm-tis-i2c.yaml         |  47 ++++
 drivers/char/tpm/Kconfig                           |  12 +
 drivers/char/tpm/Makefile                          |   1 +
 drivers/char/tpm/tpm2-cmd.c                        |   4 +
 drivers/char/tpm/tpm_tis_core.c                    | 180 +++++++------
 drivers/char/tpm/tpm_tis_core.h                    |  41 ++-
 drivers/char/tpm/tpm_tis_i2c.c                     | 291 +++++++++++++++++++++
 drivers/char/tpm/tpm_tis_spi_main.c                |  41 ---
 include/linux/tpm.h                                |   1 +
 9 files changed, 490 insertions(+), 128 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml
 create mode 100644 drivers/char/tpm/tpm_tis_i2c.c

-- 
2.7.4

[PATCH v7 1/7] tpm: tpm_tis: Make implementation of read16, read32 and write32 optional

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Only tpm_tis can use memory-mapped I/O, which is truly mapped into
the kernel's memory space. Therefore, using ioread16/ioread32/iowrite32
turns into a straightforward pointer dereference.
Every other driver requires more complicated operations to read more than
one byte at a time and will just fall back to read_bytes/write_bytes.
Therefore, move this common code out of tpm_tis_spi and into tpm_tis_core
so that it is used automatically when low-level drivers do not implement
the specialized methods.

Co-developed-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm_tis_core.h     | 38 +++++++++++++++++++++++++++++++---
 drivers/char/tpm/tpm_tis_spi_main.c | 41 -------------------------------------
 2 files changed, 35 insertions(+), 44 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
index 7337819..d06c65b 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -122,13 +122,35 @@ static inline int tpm_tis_read8(struct tpm_tis_data *data, u32 addr, u8 *result)
 static inline int tpm_tis_read16(struct tpm_tis_data *data, u32 addr,
 				 u16 *result)
 {
-	return data->phy_ops->read16(data, addr, result);
+	__le16 result_le;
+	int rc;
+
+	if (data->phy_ops->read16)
+		return data->phy_ops->read16(data, addr, result);
+
+	rc = data->phy_ops->read_bytes(data, addr, sizeof(u16),
+				       (u8 *)&result_le);
+	if (!rc)
+		*result = le16_to_cpu(result_le);
+
+	return rc;
 }
 
 static inline int tpm_tis_read32(struct tpm_tis_data *data, u32 addr,
 				 u32 *result)
 {
-	return data->phy_ops->read32(data, addr, result);
+	__le32 result_le;
+	int rc;
+
+	if (data->phy_ops->read32)
+		return data->phy_ops->read32(data, addr, result);
+
+	rc = data->phy_ops->read_bytes(data, addr, sizeof(u32),
+				       (u8 *)&result_le);
+	if (!rc)
+		*result = le32_to_cpu(result_le);
+
+	return rc;
 }
 
 static inline int tpm_tis_write_bytes(struct tpm_tis_data *data, u32 addr,
@@ -145,7 +167,17 @@ static inline int tpm_tis_write8(struct tpm_tis_data *data, u32 addr, u8 value)
 static inline int tpm_tis_write32(struct tpm_tis_data *data, u32 addr,
 				  u32 value)
 {
-	return data->phy_ops->write32(data, addr, value);
+	__le32 value_le;
+	int rc;
+
+	if (data->phy_ops->write32)
+		return data->phy_ops->write32(data, addr, value);
+
+	value_le = cpu_to_le32(value);
+	rc = data->phy_ops->write_bytes(data, addr, sizeof(u32),
+					(u8 *)&value_le);
+
+	return rc;
 }
 
 static inline bool is_bsw(void)
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index d1754fd..95fef9d 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -152,44 +152,6 @@ static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
 	return tpm_tis_spi_transfer(data, addr, len, NULL, value);
 }
 
-int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
-{
-	__le16 result_le;
-	int rc;
-
-	rc = data->phy_ops->read_bytes(data, addr, sizeof(u16),
-				       (u8 *)&result_le);
-	if (!rc)
-		*result = le16_to_cpu(result_le);
-
-	return rc;
-}
-
-int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
-{
-	__le32 result_le;
-	int rc;
-
-	rc = data->phy_ops->read_bytes(data, addr, sizeof(u32),
-				       (u8 *)&result_le);
-	if (!rc)
-		*result = le32_to_cpu(result_le);
-
-	return rc;
-}
-
-int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
-{
-	__le32 value_le;
-	int rc;
-
-	value_le = cpu_to_le32(value);
-	rc = data->phy_ops->write_bytes(data, addr, sizeof(u32),
-					(u8 *)&value_le);
-
-	return rc;
-}
-
 int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
 		     int irq, const struct tpm_tis_phy_ops *phy_ops)
 {
@@ -205,9 +167,6 @@ int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
 static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
 	.read_bytes = tpm_tis_spi_read_bytes,
 	.write_bytes = tpm_tis_spi_write_bytes,
-	.read16 = tpm_tis_spi_read16,
-	.read32 = tpm_tis_spi_read32,
-	.write32 = tpm_tis_spi_write32,
 };
 
 static int tpm_tis_spi_probe(struct spi_device *dev)
-- 
2.7.4

[PATCH v7 2/7] tpm: tpm_tis: Add verify_data_integrity handle toy tpm_tis_phy_ops

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

To validate data integrity we need to compute the CRC over the data
sent at a lower layer (I2C for instance).
To do this, tpm_tis_verify_data_integrity() calls a "verify_data_integrity"
operation (if available).
If the data integrity check fails, a retry to save the sent/received
data is implemented in the tpm_tis_send_main()/tpm_tis_recv() functions.

Co-developed-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 104 +++++++++++++++++++++++++---------------
 drivers/char/tpm/tpm_tis_core.h |   3 ++
 2 files changed, 69 insertions(+), 38 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 27c6ca0..5dd5604 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -242,6 +242,17 @@ static u8 tpm_tis_status(struct tpm_chip *chip)
 	return status;
 }
 
+static bool tpm_tis_verify_data_integrity(struct tpm_chip *chip, const u8 *buf,
+					  size_t len)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+
+	if (priv->phy_ops->verify_data_integrity)
+		return priv->phy_ops->verify_data_integrity(priv, buf, len);
+
+	return true;
+}
+
 static void tpm_tis_ready(struct tpm_chip *chip)
 {
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
@@ -308,47 +319,59 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 {
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 	int size = 0;
-	int status;
+	int status, i;
 	u32 expected;
+	bool data_valid = false;
 
-	if (count < TPM_HEADER_SIZE) {
-		size = -EIO;
-		goto out;
-	}
+	for (i = 0; i < TPM_RETRY; i++) {
+		if (count < TPM_HEADER_SIZE) {
+			size = -EIO;
+			goto out;
+		}
 
-	size = recv_data(chip, buf, TPM_HEADER_SIZE);
-	/* read first 10 bytes, including tag, paramsize, and result */
-	if (size < TPM_HEADER_SIZE) {
-		dev_err(&chip->dev, "Unable to read header\n");
-		goto out;
-	}
+		size = recv_data(chip, buf, TPM_HEADER_SIZE);
+		/* read first 10 bytes, including tag, paramsize, and result */
+		if (size < TPM_HEADER_SIZE) {
+			dev_err(&chip->dev, "Unable to read header\n");
+			goto out;
+		}
 
-	expected = be32_to_cpu(*(__be32 *) (buf + 2));
-	if (expected > count || expected < TPM_HEADER_SIZE) {
-		size = -EIO;
-		goto out;
-	}
+		expected = be32_to_cpu(*(__be32 *) (buf + 2));
+		if (expected > count || expected < TPM_HEADER_SIZE) {
+			size = -EIO;
+			goto out;
+		}
 
-	size += recv_data(chip, &buf[TPM_HEADER_SIZE],
-			  expected - TPM_HEADER_SIZE);
-	if (size < expected) {
-		dev_err(&chip->dev, "Unable to read remainder of result\n");
-		size = -ETIME;
-		goto out;
-	}
+		size += recv_data(chip, &buf[TPM_HEADER_SIZE],
+				  expected - TPM_HEADER_SIZE);
+		if (size < expected) {
+			dev_err(&chip->dev, "Unable to read remainder of result\n");
+			size = -ETIME;
+			goto out;
+		}
 
-	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-				&priv->int_queue, false) < 0) {
-		size = -ETIME;
-		goto out;
+		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
+				      &priv->int_queue, false) < 0) {
+			size = -ETIME;
+			goto out;
+		}
+
+		status = tpm_tis_status(chip);
+		if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
+			dev_err(&chip->dev, "Error left over data\n");
+			size = -EIO;
+			goto out;
+		}
+
+		data_valid = tpm_tis_verify_data_integrity(chip, buf, size);
+		if (!data_valid)
+			tpm_tis_write8(priv, TPM_STS(priv->locality),
+				       TPM_STS_RESPONSE_RETRY);
+		else
+			break;
 	}
-	status = tpm_tis_status(chip);
-	if (status & TPM_STS_DATA_AVAIL) {	/* retry? */
-		dev_err(&chip->dev, "Error left over data\n");
+	if (!data_valid)
 		size = -EIO;
-		goto out;
-	}
-
 out:
 	tpm_tis_ready(chip);
 	return size;
@@ -453,14 +476,19 @@ static void disable_interrupts(struct tpm_chip *chip)
 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
 {
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
-	int rc;
+	int rc, i;
 	u32 ordinal;
 	unsigned long dur;
+	bool data_valid = false;
 
-	rc = tpm_tis_send_data(chip, buf, len);
-	if (rc < 0)
-		return rc;
-
+	for (i = 0; i < TPM_RETRY && !data_valid; i++) {
+		rc = tpm_tis_send_data(chip, buf, len);
+		if (rc < 0)
+			return rc;
+		data_valid = tpm_tis_verify_data_integrity(chip, buf, len);
+	}
+	if (!data_valid)
+		return -EIO;
 	/* go and do it */
 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
 	if (rc < 0)
diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h
index d06c65b..cd97c01 100644
--- a/drivers/char/tpm/tpm_tis_core.h
+++ b/drivers/char/tpm/tpm_tis_core.h
@@ -34,6 +34,7 @@ enum tis_status {
 	TPM_STS_GO = 0x20,
 	TPM_STS_DATA_AVAIL = 0x10,
 	TPM_STS_DATA_EXPECT = 0x08,
+	TPM_STS_RESPONSE_RETRY = 0x02,
 };
 
 enum tis_int_flags {
@@ -106,6 +107,8 @@ struct tpm_tis_phy_ops {
 	int (*read16)(struct tpm_tis_data *data, u32 addr, u16 *result);
 	int (*read32)(struct tpm_tis_data *data, u32 addr, u32 *result);
 	int (*write32)(struct tpm_tis_data *data, u32 addr, u32 src);
+	bool (*verify_data_integrity)(struct tpm_tis_data *data, const u8 *buf,
+				      size_t len);
 };
 
 static inline int tpm_tis_read_bytes(struct tpm_tis_data *data, u32 addr,
-- 
2.7.4

[PATCH v7 3/7] tpm: tpm_tis: Rewrite "tpm_tis_req_canceled()"

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Using this function while reading/writing data resulted in an aborted
operation.
After investigating the issue according to the TCG TPM Profile (PTP)
Specifications, I found that "request to cancel" should occur only if
TPM_STS.commandReady bit is lit.
Note that i couldn't find a case where the present condition
(in the linux kernel) is valid, so I'm removing the case for
"TPM_VID_WINBOND" since we have no need for it.

Also, the default comparison is wrong. Only cmdReady bit needs to be
compared instead of the full lower status register byte.

Fixes: 1f86605 (tpm: Fix cancellation of TPM commands (polling mode))
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 5dd5604..682f950 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -715,13 +715,11 @@ static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 
 	switch (priv->manufacturer_id) {
-	case TPM_VID_WINBOND:
-		return ((status == TPM_STS_VALID) ||
-			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
 	case TPM_VID_STM:
 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
 	default:
-		return (status == TPM_STS_COMMAND_READY);
+		return ((status & TPM_STS_COMMAND_READY) ==
+			TPM_STS_COMMAND_READY);
 	}
 }
 
-- 
2.7.4

[PATCH v7 4/7] tpm: tpm_tis: Fix expected bit handling and send all bytes in one shot without last byte in exception

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Incorrect implementation of send message was detected. We polled only
TPM_STS.stsValid bit and then we single-checked the TPM_STS.expect bit
value.
TPM_STS.expected bit should be checked at the same time as
TPM_STS.stsValid bit, and this should be repeated until timeout_A.

To detect a TPM_STS.expected bit reset, the "wait_for_tpm_stat" function is
modified to "wait_for_tpm_stat_result". This function regularly reads the
status register and check the bits defined by "mask" to reach the value
defined in "mask_result".

This correct implementation is required for using the new CRC calculation
on I2C TPM command bytes or I2C TPM answer bytes. TPM_STS.expected bit is
reset after all bytes are acquired and the CRC result is inserted in the
dedicated register. It introduces a normal latency for TPM_STS.expected
bit reset.

Respectively, to send a message, as defined in
TCG_DesignPrinciples_TPM2p0Driver_vp24_pubrev.pdf, all bytes should be
sent in one shot instead of sending the last byte separately.

Suggested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 74 +++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 44 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 682f950..f71ecd8 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -44,9 +44,10 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 	return false;
 }
 
-static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
-		unsigned long timeout, wait_queue_head_t *queue,
-		bool check_cancel)
+static int wait_for_tpm_stat_result(struct tpm_chip *chip, u8 mask,
+				    u8 mask_result, unsigned long timeout,
+				    wait_queue_head_t *queue,
+				    bool check_cancel)
 {
 	unsigned long stop;
 	long rc;
@@ -55,7 +56,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
 
 	/* check current status */
 	status = chip->ops->status(chip);
-	if ((status & mask) == mask)
+	if ((status & mask) == mask_result)
 		return 0;
 
 	stop = jiffies + timeout;
@@ -83,7 +84,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
 			usleep_range(TPM_TIMEOUT_USECS_MIN,
 				     TPM_TIMEOUT_USECS_MAX);
 			status = chip->ops->status(chip);
-			if ((status & mask) == mask)
+			if ((status & mask) == mask_result)
 				return 0;
 		} while (time_before(jiffies, stop));
 	}
@@ -292,10 +293,13 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 	int size = 0, burstcnt, rc;
 
 	while (size < count) {
-		rc = wait_for_tpm_stat(chip,
-				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
-				 chip->timeout_c,
-				 &priv->read_queue, true);
+		rc = wait_for_tpm_stat_result(chip,
+					      TPM_STS_DATA_AVAIL |
+					      TPM_STS_VALID,
+					      TPM_STS_DATA_AVAIL |
+					      TPM_STS_VALID,
+					      chip->timeout_c,
+					      &priv->read_queue, true);
 		if (rc < 0)
 			return rc;
 		burstcnt = get_burstcount(chip);
@@ -350,8 +354,9 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 			goto out;
 		}
 
-		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-				      &priv->int_queue, false) < 0) {
+		if (wait_for_tpm_stat_result(chip, TPM_STS_VALID,
+					     TPM_STS_VALID, chip->timeout_c,
+					     &priv->int_queue, false) < 0) {
 			size = -ETIME;
 			goto out;
 		}
@@ -387,61 +392,40 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 	int rc, status, burstcnt;
 	size_t count = 0;
-	bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
 
 	status = tpm_tis_status(chip);
 	if ((status & TPM_STS_COMMAND_READY) == 0) {
 		tpm_tis_ready(chip);
-		if (wait_for_tpm_stat
-		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
-		     &priv->int_queue, false) < 0) {
+		if (wait_for_tpm_stat_result(chip, TPM_STS_COMMAND_READY,
+					     TPM_STS_COMMAND_READY,
+					     chip->timeout_b,
+					     &priv->int_queue, false) < 0) {
 			rc = -ETIME;
 			goto out_err;
 		}
 	}
 
-	while (count < len - 1) {
+	while (count < len) {
 		burstcnt = get_burstcount(chip);
 		if (burstcnt < 0) {
 			dev_err(&chip->dev, "Unable to read burstcount\n");
 			rc = burstcnt;
 			goto out_err;
 		}
-		burstcnt = min_t(int, burstcnt, len - count - 1);
+		burstcnt = min_t(int, burstcnt, len - count);
 		rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
 					 burstcnt, buf + count);
 		if (rc < 0)
 			goto out_err;
 
 		count += burstcnt;
-
-		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-					&priv->int_queue, false) < 0) {
-			rc = -ETIME;
-			goto out_err;
-		}
-		status = tpm_tis_status(chip);
-		if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
-			rc = -EIO;
-			goto out_err;
-		}
 	}
-
-	/* write last byte */
-	rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
-	if (rc < 0)
-		goto out_err;
-
-	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-				&priv->int_queue, false) < 0) {
+	if (wait_for_tpm_stat_result(chip, TPM_STS_VALID | TPM_STS_DATA_EXPECT,
+				     TPM_STS_VALID, chip->timeout_a,
+				     &priv->int_queue, false) < 0) {
 		rc = -ETIME;
 		goto out_err;
 	}
-	status = tpm_tis_status(chip);
-	if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
-		rc = -EIO;
-		goto out_err;
-	}
 
 	return 0;
 
@@ -498,9 +482,11 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 
 		dur = tpm_calc_ordinal_duration(chip, ordinal);
-		if (wait_for_tpm_stat
-		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
-		     &priv->read_queue, false) < 0) {
+		if (wait_for_tpm_stat_result(chip,
+					     TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+					     TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+					     dur,
+					     &priv->read_queue, false) < 0) {
 			rc = -ETIME;
 			goto out_err;
 		}
-- 
2.7.4

[PATCH v7 5/7] tpm: Handle an exception for TPM Firmware Update mode.

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

An extra precaution for TPM Firmware Update Mode.
For example if TPM power was cut while in Firmware update, platform
should ignore "selftest" failure and skip TPM initialization sequence.

Suggested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm2-cmd.c | 4 ++++
 include/linux/tpm.h         | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index 7603295..6e42946 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -727,6 +727,10 @@ int tpm2_auto_startup(struct tpm_chip *chip)
 		goto out;
 
 	rc = tpm2_do_selftest(chip);
+
+	if (rc == TPM2_RC_UPGRADE || rc == TPM2_RC_COMMAND_CODE)
+		return 0;
+
 	if (rc && rc != TPM2_RC_INITIALIZE)
 		goto out;
 
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 03e9b18..5a2e031 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -199,6 +199,7 @@ enum tpm2_return_codes {
 	TPM2_RC_INITIALIZE	= 0x0100, /* RC_VER1 */
 	TPM2_RC_FAILURE		= 0x0101,
 	TPM2_RC_DISABLED	= 0x0120,
+	TPM2_RC_UPGRADE         = 0x012D,
 	TPM2_RC_COMMAND_CODE    = 0x0143,
 	TPM2_RC_TESTING		= 0x090A, /* RC_WARN */
 	TPM2_RC_REFERENCE_H0	= 0x0910,
-- 
2.7.4

[PATCH v7 6/7] tpm: Add YAML schema for TPM TIS I2C options

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Added a YAML schema to support tpm tis i2c related dt-bindings for the I2c
PTP based physical layer.

This patch adds the documentation for corresponding device tree bindings of
I2C based Physical TPM.
Refer to the 'I2C Interface Definition' section in
'TCG PC Client PlatformTPMProfile(PTP) Specification' publication
for specification.

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 .../bindings/security/tpm/tpm-tis-i2c.yaml         | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml

diff --git a/Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml b/Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml
new file mode 100644
index 0000000..2ab8b80
--- /dev/null
+++ b/Documentation/devicetree/bindings/security/tpm/tpm-tis-i2c.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/security/tpm/tpm-tis-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: I2C PTP based TPM Device Tree Bindings
+
+maintainers:
+  - Amir Mizinski <amirmizi6@gmail.com>
+
+description:
+  Device Tree Bindings for I2C based Trusted Platform Module(TPM).
+
+properties:
+  compatible:
+    contains:
+      const: tcg,tpm-tis-i2c
+
+  reg:
+    maxItems: 1
+
+  interrupt:
+    maxItems: 1
+
+  crc-checksum:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Set this flag to enable CRC checksum.
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      tpm_tis@2e {
+        compatible = "tcg,tpm-tis-i2c";
+        reg = <0x2e>;
+        crc-checksum;
+      };
+    };
+...
-- 
2.7.4

[PATCH v7 7/7] tpm: tpm_tis: add tpm_tis_i2c driver

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Implements the functionality needed to communicate with an I2C TPM
according to the TCG TPM I2C Interface Specification.

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
Tested-by: Eddie James <eajames@linux.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
---
 drivers/char/tpm/Kconfig       |  12 ++
 drivers/char/tpm/Makefile      |   1 +
 drivers/char/tpm/tpm_tis_i2c.c | 291 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 304 insertions(+)
 create mode 100644 drivers/char/tpm/tpm_tis_i2c.c

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index aacdeed..2116d94 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -74,6 +74,18 @@ config TCG_TIS_SPI_CR50
 	  If you have a H1 secure module running Cr50 firmware on SPI bus,
 	  say Yes and it will be accessible from within Linux.
 
+config TCG_TIS_I2C
+	tristate "TPM I2C Interface Specification"
+	depends on I2C
+	select CRC_CCITT
+	select TCG_TIS_CORE
+	help
+	  If you have a TPM security chip which is connected to a regular
+	  I2C master (i.e. most embedded platforms) that is compliant with the
+	  TCG TPM I2C Interface Specification say Yes and it will be accessible from
+	  within Linux. To compile this driver as a module, choose  M here;
+	  the module will be called tpm_tis_i2c.
+
 config TCG_TIS_I2C_ATMEL
 	tristate "TPM Interface Specification 1.2 Interface (I2C - Atmel)"
 	depends on I2C
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 9567e51..97999cf 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o
 tpm_tis_spi-y := tpm_tis_spi_main.o
 tpm_tis_spi-$(CONFIG_TCG_TIS_SPI_CR50) += tpm_tis_spi_cr50.o
 
+obj-$(CONFIG_TCG_TIS_I2C) += tpm_tis_i2c.o
 obj-$(CONFIG_TCG_TIS_I2C_ATMEL) += tpm_i2c_atmel.o
 obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
 obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o
diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c
new file mode 100644
index 0000000..9963e9e
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_i2c.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2019 Nuvoton Technology corporation
+ *
+ * TPM TIS I2C
+ *
+ * TPM TIS I2C Device Driver Interface for devices that implement the TPM I2C
+ * Interface defined by TCG PC Client Platform TPM Profile (PTP) Specification
+ * Revision 01.03 v22 at www.trustedcomputinggroup.org
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/acpi.h>
+#include <linux/freezer.h>
+#include <linux/crc-ccitt.h>
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/tpm.h>
+#include "tpm.h"
+#include "tpm_tis_core.h"
+
+#define TPM_LOC_SEL                    0x04
+#define TPM_I2C_INTERFACE_CAPABILITY   0x30
+#define TPM_I2C_DEVICE_ADDRESS         0x38
+#define TPM_DATA_CSUM_ENABLE           0x40
+#define TPM_DATA_CSUM                  0x44
+#define TPM_I2C_DID_VID                        0x48
+#define TPM_I2C_RID                    0x4C
+
+//#define I2C_IS_TPM2 1
+
+struct tpm_tis_i2c_phy {
+	struct tpm_tis_data priv;
+	struct i2c_client *i2c_client;
+	bool data_csum;
+	u8 *iobuf;
+};
+
+static inline struct tpm_tis_i2c_phy *to_tpm_tis_i2c_phy(struct tpm_tis_data
+							 *data)
+{
+	return container_of(data, struct tpm_tis_i2c_phy, priv);
+}
+
+static u8 address_to_register(u32 addr)
+{
+	addr &= 0xFFF;
+
+	switch (addr) {
+		// adapt register addresses that have changed compared to
+		// older TIS versions
+	case TPM_ACCESS(0):
+		return 0x04;
+	case TPM_LOC_SEL:
+		return 0x00;
+	case TPM_DID_VID(0):
+		return 0x48;
+	case TPM_RID(0):
+		return 0x4C;
+	default:
+		return addr;
+	}
+}
+
+static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr,
+				  u16 len, u8 *result)
+{
+	struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data);
+	int ret = 0;
+	int i = 0;
+	u8 reg = address_to_register(addr);
+	struct i2c_msg msgs[] = {
+		{
+			.addr = phy->i2c_client->addr,
+			.len = sizeof(reg),
+			.buf = &reg,
+		},
+		{
+			.addr = phy->i2c_client->addr,
+			.len = len,
+			.buf = result,
+			.flags = I2C_M_RD,
+		},
+	};
+
+	do {
+		ret = i2c_transfer(phy->i2c_client->adapter, msgs,
+				   ARRAY_SIZE(msgs));
+		usleep_range(250, 300); // wait default GUARD_TIME of 250µs
+
+	} while (ret < 0 && i++ < TPM_RETRY);
+
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int tpm_tis_i2c_write_bytes(struct tpm_tis_data *data, u32 addr,
+				   u16 len, const u8 *value)
+{
+	struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data);
+	int ret = 0;
+	int i = 0;
+
+	if (phy->iobuf) {
+		if (len > TPM_BUFSIZE - 1)
+			return -EIO;
+
+		phy->iobuf[0] = address_to_register(addr);
+		memcpy(phy->iobuf + 1, value, len);
+
+		{
+			struct i2c_msg msgs[] = {
+				{
+					.addr = phy->i2c_client->addr,
+					.len = len + 1,
+					.buf = phy->iobuf,
+				},
+			};
+
+			do {
+				ret = i2c_transfer(phy->i2c_client->adapter,
+						   msgs, ARRAY_SIZE(msgs));
+				// wait default GUARD_TIME of 250µs
+				usleep_range(250, 300);
+			} while (ret < 0 && i++ < TPM_RETRY);
+		}
+	} else {
+		u8 reg = address_to_register(addr);
+
+		struct i2c_msg msgs[] = {
+			{
+				.addr = phy->i2c_client->addr,
+				.len = sizeof(reg),
+				.buf = &reg,
+			},
+			{
+				.addr = phy->i2c_client->addr,
+				.len = len,
+				.buf = (u8 *)value,
+				.flags = I2C_M_NOSTART,
+			},
+		};
+		do {
+			ret = i2c_transfer(phy->i2c_client->adapter, msgs,
+					   ARRAY_SIZE(msgs));
+			// wait default GUARD_TIME of 250µs
+			usleep_range(250, 300);
+		} while (ret < 0 && i++ < TPM_RETRY);
+	}
+
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static bool tpm_tis_i2c_verify_data_integrity(struct tpm_tis_data *data,
+					      const u8 *buf, size_t len)
+{
+	struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data);
+	u16 crc, crc_tpm;
+	int rc;
+
+	if (phy->data_csum) {
+		crc = crc_ccitt(0x0000, buf, len);
+		rc = tpm_tis_read16(data, TPM_DATA_CSUM, &crc_tpm);
+		if (rc < 0)
+			return false;
+
+		crc_tpm = be16_to_cpu(crc_tpm);
+		return crc == crc_tpm;
+	}
+
+	return true;
+}
+
+static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
+
+static int csum_state_store(struct tpm_tis_data *data, u8 new_state)
+{
+	struct tpm_tis_i2c_phy *phy = to_tpm_tis_i2c_phy(data);
+	u8 cur_state;
+	int rc;
+
+	rc = tpm_tis_i2c_write_bytes(&phy->priv, TPM_DATA_CSUM_ENABLE,
+				     1, &new_state);
+	if (rc < 0)
+		return rc;
+
+	rc = tpm_tis_i2c_read_bytes(&phy->priv, TPM_DATA_CSUM_ENABLE,
+				    1, &cur_state);
+	if (rc < 0)
+		return rc;
+
+	if (new_state == cur_state)
+		phy->data_csum = (bool)new_state;
+
+	return rc;
+}
+
+static const struct tpm_tis_phy_ops tpm_i2c_phy_ops = {
+	.read_bytes = tpm_tis_i2c_read_bytes,
+	.write_bytes = tpm_tis_i2c_write_bytes,
+	.verify_data_integrity = tpm_tis_i2c_verify_data_integrity,
+};
+
+static int tpm_tis_i2c_probe(struct i2c_client *dev,
+			     const struct i2c_device_id *id)
+{
+	struct tpm_tis_i2c_phy *phy;
+	int rc;
+	int crc_checksum = 0;
+	const u8 loc_init = 0;
+	struct device_node *np;
+
+	phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_i2c_phy),
+			   GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->i2c_client = dev;
+
+	if (!i2c_check_functionality(dev->adapter, I2C_FUNC_NOSTART)) {
+		phy->iobuf = devm_kmalloc(&dev->dev, TPM_BUFSIZE, GFP_KERNEL);
+		if (!phy->iobuf)
+			return -ENOMEM;
+	}
+
+	// select locality 0 (the driver will access only via locality 0)
+	rc = tpm_tis_i2c_write_bytes(&phy->priv, TPM_LOC_SEL, 1, &loc_init);
+	if (rc < 0)
+		return rc;
+
+	// set CRC checksum calculation enable
+	np = dev->dev.of_node;
+	if (of_property_read_bool(np, "crc-checksum"))
+		crc_checksum = 1;
+
+	rc = csum_state_store(&phy->priv, crc_checksum);
+	if (rc < 0)
+		return rc;
+
+	return tpm_tis_core_init(&dev->dev, &phy->priv, -1, &tpm_i2c_phy_ops,
+					NULL);
+}
+
+static const struct i2c_device_id tpm_tis_i2c_id[] = {
+	{"tpm_tis_i2c", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_id);
+
+static const struct of_device_id of_tis_i2c_match[] = {
+	{ .compatible = "tcg,tpm-tis-i2c", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_tis_i2c_match);
+
+static const struct acpi_device_id acpi_tis_i2c_match[] = {
+	{"SMO0768", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, acpi_tis_i2c_match);
+
+static struct i2c_driver tpm_tis_i2c_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "tpm_tis_i2c",
+		.pm = &tpm_tis_pm,
+		.of_match_table = of_match_ptr(of_tis_i2c_match),
+		.acpi_match_table = ACPI_PTR(acpi_tis_i2c_match),
+	},
+	.probe = tpm_tis_i2c_probe,
+	.id_table = tpm_tis_i2c_id,
+};
+
+module_i2c_driver(tpm_tis_i2c_driver);
+
+MODULE_DESCRIPTION("TPM Driver");
+MODULE_LICENSE("GPL");
-- 
2.7.4

Re: [PATCH v7 2/7] tpm: tpm_tis: Add verify_data_integrity handle toy tpm_tis_phy_ops

[Jarkko Sakkinen]

On Mon, Apr 27, 2020 at 03:49:26PM +0300, amirmizi6@gmail.com wrote:
> +	bool (*verify_data_integrity)(struct tpm_tis_data *data, const u8 *buf,
> +				      size_t len);

Why can't the i2c driver verify this in the end of read_bytes()?

/Jarkko

Re: [PATCH v7 3/7] tpm: tpm_tis: Rewrite "tpm_tis_req_canceled()"

[Jarkko Sakkinen]

On Mon, Apr 27, 2020 at 03:49:27PM +0300, amirmizi6@gmail.com wrote:
> From: Amir Mizinski <amirmizi6@gmail.com>
> 
> Using this function while reading/writing data resulted in an aborted
> operation.
> After investigating the issue according to the TCG TPM Profile (PTP)
> Specifications, I found that "request to cancel" should occur only if
> TPM_STS.commandReady bit is lit.
> Note that i couldn't find a case where the present condition
> (in the linux kernel) is valid, so I'm removing the case for
> "TPM_VID_WINBOND" since we have no need for it.
> 
> Also, the default comparison is wrong. Only cmdReady bit needs to be
> compared instead of the full lower status register byte.
> 
> Fixes: 1f86605 (tpm: Fix cancellation of TPM commands (polling mode))

Needs to have exactly 12 hex digits of the hash.

/Jarkko

Re: [PATCH v7 2/7] tpm: tpm_tis: Add verify_data_integrity handle toy tpm_tis_phy_ops

[Amir Mizinski]

On 2020-04-29 05:34, Jarkko Sakkinen wrote:
> On Mon, Apr 27, 2020 at 03:49:26PM +0300, amirmizi6@gmail.com wrote:
>> +    bool (*verify_data_integrity)(struct tpm_tis_data *data, const u8 *buf,
>> +                      size_t len);
>
> Why can't the i2c driver verify this in the end of read_bytes()?
>

The TPM calculates the checksum of the entire command data at the end
of command transmission or the checksum of the entire response data at the
end of response transmission.
read_bytes is not necessarily called at the end of response transmission. Same for write_bytes.

> /Jarkko

Re: [PATCH v7 3/7] tpm: tpm_tis: Rewrite "tpm_tis_req_canceled()"

[Amir Mizinski]

On 2020-04-29 05:37, Jarkko Sakkinen wrote:
> On Mon, Apr 27, 2020 at 03:49:27PM +0300, amirmizi6@gmail.com wrote:
>> From: Amir Mizinski <amirmizi6@gmail.com>
>>
>> Using this function while reading/writing data resulted in an aborted
>> operation.
>> After investigating the issue according to the TCG TPM Profile (PTP)
>> Specifications, I found that "request to cancel" should occur only if
>> TPM_STS.commandReady bit is lit.
>> Note that i couldn't find a case where the present condition
>> (in the linux kernel) is valid, so I'm removing the case for
>> "TPM_VID_WINBOND" since we have no need for it.
>>
>> Also, the default comparison is wrong. Only cmdReady bit needs to be
>> compared instead of the full lower status register byte.
>>
>> Fixes: 1f86605 (tpm: Fix cancellation of TPM commands (polling mode))
>
> Needs to have exactly 12 hex digits of the hash.
>

Ok, i'll fix this for version 8. Thank you.

> /Jarkko

Re: [PATCH v7 6/7] tpm: Add YAML schema for TPM TIS I2C options

[Rob Herring]

On Mon, Apr 27, 2020 at 03:49:30PM +0300, amirmizi6@gmail.com wrote:
> From: Amir Mizinski <amirmizi6@gmail.com>
> 
> Added a YAML schema to support tpm tis i2c related dt-bindings for the I2c
> PTP based physical layer.
> 
> This patch adds the documentation for corresponding device tree bindings of
> I2C based Physical TPM.
> Refer to the 'I2C Interface Definition' section in
> 'TCG PC Client PlatformTPMProfile(PTP) Specification' publication
> for specification.

Again, DT bindings describe h/w devices, not just a protocol. A device 
is more than just a protocol interface. There's clocks, power rails, 
resets, interrupts, firmware, etc. 

Unless there's something special about TPM chips that makes none of this 
applicable and no chip will ever have any quirks (or extensions) in 
their protocol to work-around, then you need compatible string(s) that 
are specific to the TPM chip. You can have tcg,tpm-tis-i2c as a 
fallback, but you need specific compatible to handle any quirks.

Rob

Re: [PATCH v7 6/7] tpm: Add YAML schema for TPM TIS I2C options

[Amir Mizinski]

On 2020-05-05 16:12, Rob Herring wrote:
> On Mon, Apr 27, 2020 at 03:49:30PM +0300, amirmizi6@gmail.com wrote:
>> From: Amir Mizinski <amirmizi6@gmail.com>
>>
>> Added a YAML schema to support tpm tis i2c related dt-bindings for the I2c
>> PTP based physical layer.
>>
>> This patch adds the documentation for corresponding device tree bindings of
>> I2C based Physical TPM.
>> Refer to the 'I2C Interface Definition' section in
>> 'TCG PC Client PlatformTPMProfile(PTP) Specification' publication
>> for specification.
>
> Again, DT bindings describe h/w devices, not just a protocol. A device
> is more than just a protocol interface. There's clocks, power rails,
> resets, interrupts, firmware, etc.
>
> Unless there's something special about TPM chips that makes none of this
> applicable and no chip will ever have any quirks (or extensions) in
> their protocol to work-around, then you need compatible string(s) that
> are specific to the TPM chip. You can have tcg,tpm-tis-i2c as a
> fallback, but you need specific compatible to handle any quirks.
>
> Rob

Hello Rob, currently yes. All TPM chip are implemented according to the TGC specs and should use the same properties for this I2C driver.
I can't say for sure that it will be the case in the future. Shouldn't we use the standard "tcg,tpm-tis-i2c" compatible, and if a specific TPM chip will deviate from the specs, the vendor should add an additional compatible string for it?
Thank you,
Amir

Re: [PATCH v7 6/7] tpm: Add YAML schema for TPM TIS I2C options

[Rob Herring]

On Wed, May 6, 2020 at 10:20 AM Amir Mizinski <amirmizi6@gmail.com> wrote:
>
>
> On 2020-05-05 16:12, Rob Herring wrote:
> > On Mon, Apr 27, 2020 at 03:49:30PM +0300, amirmizi6@gmail.com wrote:
> >> From: Amir Mizinski <amirmizi6@gmail.com>
> >>
> >> Added a YAML schema to support tpm tis i2c related dt-bindings for the I2c
> >> PTP based physical layer.
> >>
> >> This patch adds the documentation for corresponding device tree bindings of
> >> I2C based Physical TPM.
> >> Refer to the 'I2C Interface Definition' section in
> >> 'TCG PC Client PlatformTPMProfile(PTP) Specification' publication
> >> for specification.
> >
> > Again, DT bindings describe h/w devices, not just a protocol. A device
> > is more than just a protocol interface. There's clocks, power rails,
> > resets, interrupts, firmware, etc.
> >
> > Unless there's something special about TPM chips that makes none of this
> > applicable and no chip will ever have any quirks (or extensions) in
> > their protocol to work-around, then you need compatible string(s) that
> > are specific to the TPM chip. You can have tcg,tpm-tis-i2c as a
> > fallback, but you need specific compatible to handle any quirks.
> >
> > Rob
>
> Hello Rob, currently yes. All TPM chip are implemented according to the TGC specs and should use the same properties for this I2C driver.
> I can't say for sure that it will be the case in the future.

Exactly. That's the issue. If you have just "tcg,tpm-tis-i2c" and need
to handle some difference in the future, then you can't without
updating the DT. You must be able to handle future issues without
updating the DT.

> Shouldn't we use the standard "tcg,tpm-tis-i2c" compatible, and if a specific TPM chip will deviate from the specs, the vendor should add an additional compatible string for it?

Name something where multiple vendors have implemented a spec and
there's no deviation. It simply doesn't exist. How would you know?

Does the TPM spec define all the things I listed above outside of just
the I2C protocol?

Also, what version of the spec is "tcg,tpm-tis-i2c"? Few specs have
only 1 version.

Rob