[PATCH v1 0/5] add tpm i2c ptp driver

[PATCH v1 0/5] 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.

interupts 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

Amir Mizinski (5):
  char: tpm: Make implementation of read16 read32 write32 optional
  char: tpm: Add check_data handle to tpm_tis_phy_ops in order to check
    data integrity
  char: tpm: rewrite "tpm_tis_req_canceled()"
  dt-bindings: tpm: Add the TPM TIS I2C device tree binding documentaion
  char: tpm: add tpm_tis_i2c driver

 .../bindings/security/tpm/tpm_tis_i2c.txt          |  24 ++
 drivers/char/tpm/Kconfig                           |  12 +
 drivers/char/tpm/Makefile                          |   1 +
 drivers/char/tpm/tpm_tis_core.c                    | 109 +++++----
 drivers/char/tpm/tpm_tis_core.h                    |  41 +++-
 drivers/char/tpm/tpm_tis_i2c.c                     | 272 +++++++++++++++++++++
 drivers/char/tpm/tpm_tis_spi.c                     |  41 ----
 7 files changed, 407 insertions(+), 93 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
 create mode 100644 drivers/char/tpm/tpm_tis_i2c.c

-- 
2.7.4

[PATCH v1 1/5] char: tpm: Make implementation of read16 read32 write32 optional

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

Only tpm_tis has a faster way to access multiple bytes at once, every other
driver 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.
this commit is based on previous work by Alexander Steffen

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.h | 38 +++++++++++++++++++++++++++++++++++---
 drivers/char/tpm/tpm_tis_spi.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.c b/drivers/char/tpm/tpm_tis_spi.c
index 19513e6..da82924 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -146,50 +146,9 @@ static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
 	return tpm_tis_spi_transfer(data, addr, len, NULL, value);
 }
 
-static 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;
-}
-
-static 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;
-}
-
-static 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;
-}
-
 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 v1 2/5] char: tpm: Add check_data handle to tpm_tis_phy_ops in order to check data integrity

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

The current principles:
- When sending command:
1. Host writes TPM_STS.commandReady
2. Host writes command
3. Host checks TPM received data correctly
4. if not go to step 1

- When receiving data:
1. Host check TPM_STS.dataAvail is set
2. Host get data
3. Host check received data are correct.
4. if not Host write TPM_STS.responseRetry and go to step 1.

this commit is based on previous work by Christophe Richard

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 97 +++++++++++++++++++++++++----------------
 drivers/char/tpm/tpm_tis_core.h |  3 ++
 2 files changed, 62 insertions(+), 38 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c3181ea..ce7f8a1 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 +317,55 @@ 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 && !check_data; 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;
-	}
-	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;
-	}
+		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);
+	}
 out:
 	tpm_tis_ready(chip);
 	return size;
@@ -453,13 +470,17 @@ 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);
+	}
 
 	/* go and do it */
 	rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
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 v1 3/5] char: tpm: 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.
also only cmdReady bit need to be compared instead of the full lower status register byte.

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index ce7f8a1..9016f06 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -627,17 +627,7 @@ static int probe_itpm(struct tpm_chip *chip)
 
 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);
 }
 
 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
-- 
2.7.4

[PATCH v1 4/5] dt-bindings: tpm: Add the TPM TIS I2C device tree binding documentaion

[amirmizi6]

From: Amir Mizinski <amirmizi6@gmail.com>

this file aim at documenting TPM TIS I2C related dt-bindings for the I2C PTP based Physical TPM.

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 .../bindings/security/tpm/tpm_tis_i2c.txt          | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt

diff --git a/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
new file mode 100644
index 0000000..7d5a69e
--- /dev/null
+++ b/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
@@ -0,0 +1,24 @@
+* Device Tree Bindings for I2C PTP based Trusted Platform Module(TPM)
+
+The TCG defines hardware protocol, registers and interface (based
+on the TPM Interface Specification) for accessing TPM devices
+implemented with an I2C interface.
+
+Refer to the 'I2C Interface Definition' section in 'TCG PC Client
+PlatformTPMProfile(PTP) Specification' publication for specification.
+
+Required properties:
+
+- compatible     : Should be "tcg,tpm_tis-i2c"
+- reg            : Address on the bus
+- tpm-pirq       : Input gpio pin, used for host interrupts
+
+Example (for Raspberry Pie 3 Board with Nuvoton's NPCT75X (2.0)
+-------------------------------------------------------------------
+
+tpm_tis-i2c: tpm_tis-i2c@2e {
+
+       compatible = "tcg,tpm_tis-i2c";
+       reg = <0x2e>;
+       tpm-pirq = <&gpio 24 GPIO_ACTIVE_HIGH>;
+};
-- 
2.7.4

[PATCH v1 5/5] char: tpm: 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.

Limitations:
* No IRQ support
* No support for updating GUARD_TIME 
Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/Kconfig       |  12 ++
 drivers/char/tpm/Makefile      |   1 +
 drivers/char/tpm/tpm_tis_i2c.c | 272 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 285 insertions(+)
 create mode 100644 drivers/char/tpm/tpm_tis_i2c.c

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 88a3c06..b731a80 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -67,6 +67,18 @@ config TCG_TIS_SPI
 	  within Linux. To compile this driver as a module, choose  M here;
 	  the module will be called tpm_tis_spi.
 
+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 a01c4ca..15a0010 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -22,6 +22,7 @@ tpm-$(CONFIG_OF) += eventlog/of.o
 obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
 obj-$(CONFIG_TCG_TIS) += tpm_tis.o
 obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.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..080e82e
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_i2c.c
@@ -0,0 +1,272 @@
+// 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
+
+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;
+	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,
+		},
+	};
+
+	ret = i2c_transfer(phy->i2c_client->adapter, msgs, ARRAY_SIZE(msgs));
+
+	if (ret < 0)
+		return ret;
+
+	usleep_range(250, 300); // wait default GUARD_TIME of 250µs
+
+	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;
+
+	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,
+				},
+			};
+
+			ret = i2c_transfer(phy->i2c_client->adapter, msgs,
+					   ARRAY_SIZE(msgs));
+		}
+	} 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,
+			},
+		};
+
+		ret = i2c_transfer(phy->i2c_client->adapter, msgs,
+				   ARRAY_SIZE(msgs));
+	}
+
+	if (ret < 0)
+		return ret;
+
+	usleep_range(250, 300); // wait default GUARD_TIME of 250µs
+
+	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;
+	const u8 loc_init = 0;
+
+	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;
+
+	// enables the data checksum calculation
+	rc = csum_state_store(&phy->priv, 0x01);
+	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 for native I2C access");
+MODULE_LICENSE("GPL");
-- 
2.7.4

Re: [PATCH v1 3/5] char: tpm: rewrite "tpm_tis_req_canceled()"

[Jerry Snitselaar]

On Sun Nov 10 19, amirmizi6@gmail.com wrote:
>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.
>also only cmdReady bit need to be compared instead of the full lower status register byte.
>
>Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
>---
> drivers/char/tpm/tpm_tis_core.c | 12 +-----------
> 1 file changed, 1 insertion(+), 11 deletions(-)
>
>diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
>index ce7f8a1..9016f06 100644
>--- a/drivers/char/tpm/tpm_tis_core.c
>+++ b/drivers/char/tpm/tpm_tis_core.c
>@@ -627,17 +627,7 @@ static int probe_itpm(struct tpm_chip *chip)
>
> 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));

Stefan were these cases you found that were deviating from the spec? Wondering
if dropping these will cause issues for these devices.

>-	default:
>-		return (status == TPM_STS_COMMAND_READY);
>-	}
>+	return ((status & TPM_STS_COMMAND_READY) == TPM_STS_COMMAND_READY);
> }
>
> static irqreturn_t tis_int_handler(int dummy, void *dev_id)
>-- 
>2.7.4
>

Re: [PATCH v1 3/5] char: tpm: rewrite "tpm_tis_req_canceled()"

[Stefan Berger]

On 11/10/19 1:00 PM, Jerry Snitselaar wrote:
> On Sun Nov 10 19, amirmizi6@gmail.com wrote:
>> 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.
>> also only cmdReady bit need to be compared instead of the full lower 
>> status register byte.
>>
>> Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
>> ---
>> drivers/char/tpm/tpm_tis_core.c | 12 +-----------
>> 1 file changed, 1 insertion(+), 11 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_tis_core.c 
>> b/drivers/char/tpm/tpm_tis_core.c
>> index ce7f8a1..9016f06 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -627,17 +627,7 @@ static int probe_itpm(struct tpm_chip *chip)
>>
>> 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));
>
> Stefan were these cases you found that were deviating from the spec? 
> Wondering
> if dropping these will cause issues for these devices.


I believe these devices needed special handling of the status register 
as they didn't behave as the 'other' devices, so I would expect issues.

    Stefan

Re: [PATCH v1 2/5] char: tpm: Add check_data handle to tpm_tis_phy_ops in order to check data integrity

[Jarkko Sakkinen]

On Sun, Nov 10, 2019 at 06:21:34PM +0200, amirmizi6@gmail.com wrote:
> From: Amir Mizinski <amirmizi6@gmail.com>
> 
> The current principles:
> - When sending command:
> 1. Host writes TPM_STS.commandReady
> 2. Host writes command
> 3. Host checks TPM received data correctly
> 4. if not go to step 1

You are probably talking about steps, right?

Please check the grammar and punctation e.g. "The current steps are
roughly done when sending a command".

> - When receiving data:
> 1. Host check TPM_STS.dataAvail is set
> 2. Host get data
> 3. Host check received data are correct.
> 4. if not Host write TPM_STS.responseRetry and go to step 1.
> 
> this commit is based on previous work by Christophe Richard

Sentences in English start with a capital letter and end with a full
stop.

This is completely lacking the description what the commit does.

/Jarkko

Re: [PATCH v1 4/5] dt-bindings: tpm: Add the TPM TIS I2C device tree binding documentaion

[Rob Herring]

On Sun, Nov 10, 2019 at 06:21:36PM +0200, amirmizi6@gmail.com wrote:
> From: Amir Mizinski <amirmizi6@gmail.com>
> 
> this file aim at documenting TPM TIS I2C related dt-bindings for the I2C PTP based Physical TPM.
> 
> Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
> ---
>  .../bindings/security/tpm/tpm_tis_i2c.txt          | 24 ++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt

Please make this a schema. See 
Documentation/devicetree/writing-schema.rst.

> 
> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
> new file mode 100644
> index 0000000..7d5a69e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
> @@ -0,0 +1,24 @@
> +* Device Tree Bindings for I2C PTP based Trusted Platform Module(TPM)
> +
> +The TCG defines hardware protocol, registers and interface (based
> +on the TPM Interface Specification) for accessing TPM devices
> +implemented with an I2C interface.
> +
> +Refer to the 'I2C Interface Definition' section in 'TCG PC Client
> +PlatformTPMProfile(PTP) Specification' publication for specification.
> +
> +Required properties:
> +
> +- compatible     : Should be "tcg,tpm_tis-i2c"

s/_/-/

As this has to be under an I2C controller node, the '-i2c' part is 
redundant.

There's a bigger issue that the h/w here is more than just an I2C 
protocol. The chip may have multiple power supplies, clocks, reset 
lines, etc. HID over I2C seems like a similar case. Does the spec define 
*all* of that? If not, you need chip specific compatibles. You can keep 
this as a fallback though.

> +- reg            : Address on the bus
> +- tpm-pirq       : Input gpio pin, used for host interrupts

GPIO connections are properties ending in '-gpios'. However, if the only 
use is an interrupt, then you should use 'interrupts'.

> +
> +Example (for Raspberry Pie 3 Board with Nuvoton's NPCT75X (2.0)
> +-------------------------------------------------------------------
> +
> +tpm_tis-i2c: tpm_tis-i2c@2e {
> +
> +       compatible = "tcg,tpm_tis-i2c";
> +       reg = <0x2e>;
> +       tpm-pirq = <&gpio 24 GPIO_ACTIVE_HIGH>;
> +};
> -- 
> 2.7.4
> 

Re: [PATCH v1 4/5] dt-bindings: tpm: Add the TPM TIS I2C device tree binding documentaion

[Amir Mizinski]

On Thu, Nov 14, 2019 at 9:10 PM Rob Herring <robh@kernel.org> wrote:
>
> On Sun, Nov 10, 2019 at 06:21:36PM +0200, amirmizi6@gmail.com wrote:
> > From: Amir Mizinski <amirmizi6@gmail.com>
> >
> > this file aim at documenting TPM TIS I2C related dt-bindings for the I2C PTP based Physical TPM.
> >
> > Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
> > ---
> >  .../bindings/security/tpm/tpm_tis_i2c.txt          | 24 ++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
>
> Please make this a schema. See
> Documentation/devicetree/writing-schema.rst.
>
> >
> > diff --git a/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt b/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
> > new file mode 100644
> > index 0000000..7d5a69e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
> > @@ -0,0 +1,24 @@
> > +* Device Tree Bindings for I2C PTP based Trusted Platform Module(TPM)
> > +
> > +The TCG defines hardware protocol, registers and interface (based
> > +on the TPM Interface Specification) for accessing TPM devices
> > +implemented with an I2C interface.
> > +
> > +Refer to the 'I2C Interface Definition' section in 'TCG PC Client
> > +PlatformTPMProfile(PTP) Specification' publication for specification.
> > +
> > +Required properties:
> > +
> > +- compatible     : Should be "tcg,tpm_tis-i2c"
>
> s/_/-/
>
> As this has to be under an I2C controller node, the '-i2c' part is
> redundant.
>

I wrote this Respectively with the tpm_tis-spi driver.
https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/security/tpm/tpm_tis_spi.txt
Should i change it anyway or keep the format?
Also the '-i2c' is added since its not the only protocol used over
tis, and it is handled differently from spi.

> There's a bigger issue that the h/w here is more than just an I2C
> protocol. The chip may have multiple power supplies, clocks, reset
> lines, etc. HID over I2C seems like a similar case. Does the spec define
> *all* of that? If not, you need chip specific compatibles. You can keep
> this as a fallback though.
>
> > +- reg            : Address on the bus
> > +- tpm-pirq       : Input gpio pin, used for host interrupts
>
> GPIO connections are properties ending in '-gpios'. However, if the only
> use is an interrupt, then you should use 'interrupts'.
>

My mistake, i didn't implemented interrupts yet so ill clear this for
now.  thank you.

> > +
> > +Example (for Raspberry Pie 3 Board with Nuvoton's NPCT75X (2.0)
> > +-------------------------------------------------------------------
> > +
> > +tpm_tis-i2c: tpm_tis-i2c@2e {
> > +
> > +       compatible = "tcg,tpm_tis-i2c";
> > +       reg = <0x2e>;
> > +       tpm-pirq = <&gpio 24 GPIO_ACTIVE_HIGH>;
> > +};
> > --
> > 2.7.4
> >

Apologies for the late response, had a personal issue that needed my attention
I'm working on making this a schema for next version. This is new for
me, if you have additional sources regarding how to write it, i'll
appreciate if you send me.
Thank you.

Amir Mizinski

[PATCH v1 0/5] 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.

interupts 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

Amir Mizinski (5):
  char: tpm: Make implementation of read16 read32 write32 optional
  char: tpm: Add check_data handle to tpm_tis_phy_ops in order to check
    data integrity
  char: tpm: rewrite "tpm_tis_req_canceled()"
  dt-bindings: tpm: Add the TPM TIS I2C device tree binding documentaion
  char: tpm: add tpm_tis_i2c driver

 .../bindings/security/tpm/tpm_tis_i2c.txt          |  24 ++
 drivers/char/tpm/Kconfig                           |  12 +
 drivers/char/tpm/Makefile                          |   1 +
 drivers/char/tpm/tpm_tis_core.c                    | 109 +++++----
 drivers/char/tpm/tpm_tis_core.h                    |  41 +++-
 drivers/char/tpm/tpm_tis_i2c.c                     | 272 +++++++++++++++++++++
 drivers/char/tpm/tpm_tis_spi.c                     |  41 ----
 7 files changed, 407 insertions(+), 93 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_tis_i2c.txt
 create mode 100644 drivers/char/tpm/tpm_tis_i2c.c

-- 
2.7.4