Add tpm i2c ptp driver

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 exeption 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"
        -Reviewed-by:
-"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 more clear, 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/

Amir Mizinski (7):
  tpm: tpm_tis: Make implementation of read16 read32 write32 optional
  tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops in order to
    check data integrity
  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.
  dt-bindings: 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                    | 175 ++++++------
 drivers/char/tpm/tpm_tis_core.h                    |  41 ++-
 drivers/char/tpm/tpm_tis_i2c.c                     | 292 +++++++++++++++++++++
 drivers/char/tpm/tpm_tis_spi_main.c                |  41 ---
 include/linux/tpm.h                                |   1 +
 9 files changed, 486 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 v5 1/7] tpm: tpm_tis: Make implementation of read16 read32 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. So using ioread16/ioread32/iowrite32 turn into a
straightforward pointer dereference.
Every other driver require more complicated operations to read more than 1
byte at a time and will just fall back to read_bytes/write_bytes.
Therefore, move this common code out of tpm_tis_spi into tpm_tis_core, so
that it is automatically used 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 v5 2/7] tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops in order to check data integrity

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

In order to compute the crc over the data sent in lower layer
(I2C for instance), tpm_tis_check_data() calls an operation (if available)
to check data integrity. If data integrity cannot be verified, a retry
attempt to save the sent/received data is implemented.

The current steps are done when sending a command:
   1. Host writes to TPM_STS.commandReady.
   2. Host writes command.
   3. Host checks that TPM received data is valid.
   4. If data is currupted go to step 1.

When receiving data:
   1. Host checks that TPM_STS.dataAvail is set.
   2. Host saves received data.
   3. Host checks that received data is correct.
   4. If data is currupted Host writes to TPM_STS.responseRetry and go to
      step 1.

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 | 102 +++++++++++++++++++++++++---------------
 drivers/char/tpm/tpm_tis_core.h |   3 ++
 2 files changed, 67 insertions(+), 38 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 27c6ca0..6c4f232 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -242,6 +242,15 @@ static u8 tpm_tis_status(struct tpm_chip *chip)
 	return status;
 }
 
+static bool tpm_tis_check_data(struct tpm_chip *chip, const u8 *buf, size_t len)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+
+	if (priv->phy_ops->check_data)
+		return priv->phy_ops->check_data(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 +317,59 @@ 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 check_data = 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;
+		}
+
+		check_data = tpm_tis_check_data(chip, buf, size);
+		if (!check_data)
+			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 (!check_data)
 		size = -EIO;
-		goto out;
-	}
-
 out:
 	tpm_tis_ready(chip);
 	return size;
@@ -453,14 +474,19 @@ 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_check_data(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..486c2e9 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 (*check_data)(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 v5 3/7] tpm: tpm_tis: rewrite "tpm_tis_req_canceled()"

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Using this function while read/write data resulted in aborted operation.
After investigating according to TCG TPM Profile (PTP) Specifications,
i found cancel should happen only if TPM_STS.commandReady bit is lit and
couldn't find a case when the current condition is valid.
So i'm removing the case for "TPM_VID_WINBOND" since we have no need for it

Also default comparison is wrong. only cmdReady bit need 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 | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 6c4f232..453d7ef 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -713,13 +713,10 @@ 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 v5 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 to send message has been detected. We check
and loop only on TPM_STS.stsValid bit and next we single check
TPM_STS.expect bit value.
TPM_STS.expected bit should be checked in the same time of
TPM_STS.stsValid, and shall be repeated until timeout_A.

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

This correct implementation is mandatory to use new CRC calculation on I2C
TPM command bytes or I2C TPM answer bytes. TPM_STS.expected bit is reset
after all bytes acquired and CRC result inserted in dedicated register. It
introduces a normal latency to have TPM_STS.expected bit reset.

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

Suggested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 72 ++++++++++++++++-------------------------
 1 file changed, 28 insertions(+), 44 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 453d7ef..0a340c0 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));
 	}
@@ -290,10 +291,11 @@ 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);
@@ -348,8 +350,9 @@ 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;
 		}
@@ -385,61 +388,40 @@ 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;
 
@@ -496,9 +478,11 @@ 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 v5 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..b77e394 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 v5 6/7] dt-bindings: 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 realted 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..13d7c2c
--- /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:
+      CRC checksum enable.
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      tpm-tis-i2c@2e {
+        compatible = "tcg,tpm-tis-i2c";
+        reg = <0x2e>;
+        crc-checksum;
+      };
+    };
+...
-- 
2.7.4

[PATCH v5 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>
---
 drivers/char/tpm/Kconfig       |  12 ++
 drivers/char/tpm/Makefile      |   1 +
 drivers/char/tpm/tpm_tis_i2c.c | 292 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 305 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..b166ad3 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
+	depends on 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..83c0b3a
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_i2c.c
@@ -0,0 +1,292 @@
+// 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_check_data(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,
+	.check_data = tpm_tis_i2c_check_data,
+};
+
+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 v5 2/7] tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops in order to check data integrity

[Jarkko Sakkinen]

Short summary could just be:

"Add check_data handle() to struct tpm_tis_phy_ops"

and leave the reasoning to the long description.

On Sun, Apr 05, 2020 at 03:53:47PM +0300, amirmizi6@gmail.com wrote:
> From: Amir Mizinski <amirmizi6@gmail.com>
> 
> In order to compute the crc over the data sent in lower layer
> (I2C for instance), tpm_tis_check_data() calls an operation (if available)
> to check data integrity. If data integrity cannot be verified, a retry
> attempt to save the sent/received data is implemented.

It does not. The existing code does not do that.

Also it is not clear whether the steps are from existing code or
after this commit has been applied.

/Jarkko

Re: [PATCH v5 7/7] tpm: tpm_tis: add tpm_tis_i2c driver

[Joel Stanley]

On Sun, 5 Apr 2020 at 12:56, <amirmizi6@gmail.com> wrote:
>
> 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>
> ---
>  drivers/char/tpm/Kconfig       |  12 ++
>  drivers/char/tpm/Makefile      |   1 +
>  drivers/char/tpm/tpm_tis_i2c.c | 292 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 305 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..b166ad3 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
> +       depends on CRC_CCITT

All the other users in the kernel "select CRC_CCITT" instead of
depending on it. If we do that it's easier to enable this driver, so I
recommend going that route.

I tested your series (backported on to a 5.4 tree) and it worked well
on my platform. For the series:

Tested-by: Joel Stanley <joel@jms.id.au>




> +       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..83c0b3a
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_tis_i2c.c
> @@ -0,0 +1,292 @@
> +// 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_check_data(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,
> +       .check_data = tpm_tis_i2c_check_data,
> +};
> +
> +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
>