tpm: st33zp24: Add tpm st33zp24 support with i2c

Add support for TPM ST33ZP24 family with i2c.

For i2c we are relying only on DM_I2C.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>

3 files changed, 553 insertions, 0 deletions

diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index 5a75f85..9432160 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -64,4 +64,13 @@ config TPM_AUTH_SESSIONS
 	  TPM_LoadKey2 and TPM_GetPubKey are provided. Both features are
 	  available using the 'tpm' command, too.
 
+config TPM_ST33ZP24_I2C
+	bool "STMicroelectronics ST33ZP24 I2C TPM"
+	depends on TPM && DM_I2C
+	---help---
+	  This driver supports STMicroelectronics TPM devices connected on the I2C bus.
+	  The usual tpm operations and the 'tpm' command can be used to talk
+	  to the device using the standard TPM Interface Specification (TIS)
+	  protocol
+
 endmenu
diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
index 1d49e95..cb066d7 100644
--- a/drivers/tpm/Makefile
+++ b/drivers/tpm/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_TPM_ATMEL_TWI) += tpm_atmel_twi.o
 obj-$(CONFIG_TPM_TIS_INFINEON) += tpm_tis_infineon.o
 obj-$(CONFIG_TPM_TIS_LPC) += tpm_tis_lpc.o
 obj-$(CONFIG_TPM_TIS_SANDBOX) += tpm_tis_sandbox.o
+obj-$(CONFIG_TPM_ST33ZP24_I2C) += tpm_tis_st33zp24_i2c.o
diff --git a/drivers/tpm/tpm_tis_st33zp24_i2c.c b/drivers/tpm/tpm_tis_st33zp24_i2c.c
new file mode 100644
index 0000000..9e4829f
--- /dev/null
+++ b/drivers/tpm/tpm_tis_st33zp24_i2c.c
@@ -0,0 +1,543 @@
+/*
+ * STMicroelectronics TPM ST33ZP24 I2C UBOOT driver
+ *
+ * Copyright (C) 2016 STMicroelectronics
+ *
+ * Description: Device driver for ST33ZP24 I2C TPM TCG.
+ *
+ * This device driver implements the TPM interface as defined in
+ * the TCG TPM Interface Spec version 1.21, revision 1.0 and the
+ * STMicroelectronics Protocol Stack Specification version 1.2.0.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <tpm.h>
+#include <errno.h>
+#include <linux/types.h>
+#include <asm/unaligned.h>
+
+#include "tpm_tis.h"
+#include "tpm_internal.h"
+
+#define TPM_ACCESS			0x0
+#define TPM_STS				0x18
+#define TPM_DATA_FIFO			0x24
+
+#define LOCALITY0			0
+
+#define TPM_DUMMY_BYTE			0xAA
+#define TPM_ST33ZP24_I2C_SLAVE_ADDR	0x13
+
+#define TPM_WRITE_DIRECTION             0x80
+
+/*
+ * st33zp24_i2c_write8_reg
+ * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: tpm_register, the tpm tis register where the data should be written
+ * @param: tpm_data, the tpm_data to write inside the tpm_register
+ * @param: tpm_size, The length of the data
+ * @return: Number of byte written successfully else an error code.
+ */
+static int st33zp24_i2c_write8_reg(struct udevice *dev, u8 tpm_register,
+				   const u8 *tpm_data, size_t tpm_size)
+{
+	struct tpm_chip_priv *chip_priv = dev_get_uclass_priv(dev);
+
+	chip_priv->buf[0] = tpm_register;
+	memcpy(chip_priv->buf + 1, tpm_data, tpm_size);
+
+	return dm_i2c_write(dev, 0, chip_priv->buf, tpm_size + 1);
+}
+
+/*
+* st33zp24_i2c_read8_reg
+* Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
+* @param: tpm_register, the tpm tis register where the data should be read
+* @param: tpm_data, the TPM response
+* @param: tpm_size, tpm TPM response size to read.
+* @return: Number of byte read successfully else an error code.
+*/
+static int st33zp24_i2c_read8_reg(struct udevice *dev, u8 tpm_register,
+				  u8 *tpm_data, size_t tpm_size)
+{
+	int status;
+	u8 data;
+
+	data = TPM_DUMMY_BYTE;
+	status = st33zp24_i2c_write8_reg(dev, tpm_register, &data, 1);
+	if (status < 0)
+		return status;
+
+	return dm_i2c_read(dev, 0, tpm_data, tpm_size);
+}
+
+/*
+ * st33zp24_i2c_write
+ * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: phy_id, the phy description
+ * @param: tpm_register, the tpm tis register where the data should be written
+ * @param: tpm_data, the tpm_data to write inside the tpm_register
+ * @param: tpm_size, the length of the data
+ * @return: number of byte written successfully: should be one if success.
+ */
+static int st33zp24_i2c_write(struct udevice *dev, u8 tpm_register,
+			      const u8 *tpm_data, size_t tpm_size)
+{
+	return st33zp24_i2c_write8_reg(dev, tpm_register | TPM_WRITE_DIRECTION,
+				       tpm_data, tpm_size);
+}
+
+/*
+ * st33zp24_i2c_read
+ * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: phy_id, the phy description
+ * @param: tpm_register, the tpm tis register where the data should be read
+ * @param: tpm_data, the TPM response
+ * @param: tpm_size, tpm TPM response size to read.
+ * @return: number of byte read successfully: should be one if success.
+ */
+static int st33zp24_i2c_read(struct udevice *dev, u8 tpm_register,
+			     u8 *tpm_data, size_t tpm_size)
+{
+	return st33zp24_i2c_read8_reg(dev, tpm_register, tpm_data, tpm_size);
+}
+
+/*
+ * st33zp24_i2c_release_locality release the active locality
+ * @param: chip, the tpm chip description.
+ */
+static void st33zp24_i2c_release_locality(struct udevice *dev)
+{
+	u8 data = TPM_ACCESS_ACTIVE_LOCALITY;
+
+	st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
+}
+
+/*
+ * st33zp24_i2c_check_locality if the locality is active
+ * @param: chip, the tpm chip description
+ * @return: the active locality or -EACCES.
+ */
+static int st33zp24_i2c_check_locality(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	u8 data;
+	u8 status;
+
+	status = st33zp24_i2c_read(dev, TPM_ACCESS, &data, 1);
+	if (!status && (data &
+		(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+		(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
+		return chip->locality;
+
+	return -EACCES;
+}
+
+/*
+ * st33zp24_i2c_request_locality request the TPM locality
+ * @param: chip, the chip description
+ * @return: the active locality or negative value.
+ */
+static int st33zp24_i2c_request_locality(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	unsigned long start, stop;
+	long ret;
+	u8 data;
+
+	if (st33zp24_i2c_check_locality(dev) == chip->locality)
+		return chip->locality;
+
+	data = TPM_ACCESS_REQUEST_USE;
+	ret = st33zp24_i2c_write(dev, TPM_ACCESS, &data, 1);
+	if (ret < 0)
+		return ret;
+
+	/* wait for locality activated */
+	start = get_timer(0);
+	stop = chip->timeout_a;
+	do {
+		if (st33zp24_i2c_check_locality(dev) >= 0)
+			return chip->locality;
+		udelay(TPM_TIMEOUT_MS * 1000);
+	} while	 (get_timer(start) < stop);
+
+	return -EACCES;
+}
+
+/*
+ * st33zp24_i2c_status return the TPM_STS register
+ * @param: chip, the tpm chip description
+ * @return: the TPM_STS register value.
+ */
+static u8 st33zp24_i2c_status(struct udevice *dev)
+{
+	u8 data;
+
+	st33zp24_i2c_read(dev, TPM_STS, &data, 1);
+
+	return data;
+}
+
+/*
+ * st33zp24_i2c_get_burstcount return the burstcount address 0x19 0x1A
+ * @param: chip, the chip description
+ * return: the burstcount or -TPM_DRIVER_ERR in case of error.
+ */
+static int st33zp24_i2c_get_burstcount(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	unsigned long start, stop;
+	int burstcnt, status;
+	u8 tpm_reg, temp;
+
+	/* wait for burstcount */
+	start = get_timer(0);
+	stop = chip->timeout_d;
+	do {
+		tpm_reg = TPM_STS + 1;
+		status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
+		if (status < 0)
+			return -EBUSY;
+
+		tpm_reg = TPM_STS + 2;
+		burstcnt = temp;
+		status = st33zp24_i2c_read(dev, tpm_reg, &temp, 1);
+		if (status < 0)
+			return -EBUSY;
+
+		burstcnt |= temp << 8;
+		if (burstcnt)
+			return burstcnt;
+		udelay(TIS_SHORT_TIMEOUT_MS * 1000);
+	} while (get_timer(start) < stop);
+
+	return -EBUSY;
+}
+
+/*
+ * st33zp24_i2c_cancel, cancel the current command execution or
+ * set STS to COMMAND READY.
+ * @param: chip, tpm_chip description.
+ */
+static void st33zp24_i2c_cancel(struct udevice *dev)
+{
+	u8 data;
+
+	data = TPM_STS_COMMAND_READY;
+	st33zp24_i2c_write(dev, TPM_STS, &data, 1);
+}
+
+/*
+ * st33zp24_i2c_wait_for_stat wait for a TPM_STS value
+ * @param: chip, the tpm chip description
+ * @param: mask, the value mask to wait
+ * @param: timeout, the timeout
+ * @param: status,
+ * @return: the tpm status, 0 if success, -ETIME if timeout is reached.
+ */
+static int st33zp24_i2c_wait_for_stat(struct udevice *dev, u8 mask,
+				      unsigned long timeout, int *status)
+{
+	unsigned long start, stop;
+
+	/* Check current status */
+	*status = st33zp24_i2c_status(dev);
+	if ((*status & mask) == mask)
+		return 0;
+
+	start = get_timer(0);
+	stop = timeout;
+	do {
+		udelay(TPM_TIMEOUT_MS * 1000);
+		*status = st33zp24_i2c_status(dev);
+		if ((*status & mask) == mask)
+			return 0;
+	} while (get_timer(start) < stop);
+
+	return -ETIME;
+}
+
+/*
+ * st33zp24_i2c_recv_data receive data
+ * @param: chip, the tpm chip description
+ * @param: buf, the buffer where the data are received
+ * @param: count, the number of data to receive
+ * @return: the number of bytes read from TPM FIFO.
+ */
+static int st33zp24_i2c_recv_data(struct udevice *dev, u8 *buf, size_t count)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	int size = 0, burstcnt, len, ret, status;
+
+	while (size < count &&
+	       st33zp24_i2c_wait_for_stat(dev, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+				chip->timeout_c, &status) == 0) {
+		burstcnt = st33zp24_i2c_get_burstcount(dev);
+		if (burstcnt < 0)
+			return burstcnt;
+		len = min_t(int, burstcnt, count - size);
+		ret = st33zp24_i2c_read(dev, TPM_DATA_FIFO, buf + size, len);
+		if (ret < 0)
+			return ret;
+
+		size += len;
+	}
+
+	return size;
+}
+
+/*
+ * st33zp24_i2c_recv received TPM response through TPM phy.
+ * @param: chip, tpm_chip description.
+ * @param: buf,	the buffer to store data.
+ * @param: count, the number of bytes that can received (sizeof buf).
+ * @return: Returns zero in case of success else -EIO.
+ */
+static int st33zp24_i2c_recv(struct udevice *dev, u8 *buf, size_t count)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	int size, expected;
+
+	if (!chip)
+		return -ENODEV;
+
+	if (count < TPM_HEADER_SIZE) {
+		size = -EIO;
+		goto out;
+	}
+
+	size = st33zp24_i2c_recv_data(dev, buf, TPM_HEADER_SIZE);
+	if (size < TPM_HEADER_SIZE) {
+		debug("TPM error, unable to read header\n");
+		goto out;
+	}
+
+	expected = get_unaligned_be32(buf + 2);
+	if (expected > count) {
+		size = -EIO;
+		goto out;
+	}
+
+	size += st33zp24_i2c_recv_data(dev, &buf[TPM_HEADER_SIZE],
+				   expected - TPM_HEADER_SIZE);
+	if (size < expected) {
+		debug("TPM error, unable to read remaining bytes of result\n");
+		size = -EIO;
+		goto out;
+	}
+
+out:
+	st33zp24_i2c_cancel(dev);
+	st33zp24_i2c_release_locality(dev);
+
+	return size;
+}
+
+/*
+ * st33zp24_i2c_send send TPM commands through TPM phy.
+ * @param: chip, tpm_chip description.
+ * @param: buf,	the buffer to send.
+ * @param: len, the number of bytes to send.
+ * @return: Returns zero in case of success else the negative error code.
+ */
+static int st33zp24_i2c_send(struct udevice *dev, const u8 *buf, size_t len)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	u32 i, size;
+	int burstcnt, ret, status;
+	u8 data, tpm_stat;
+
+	if (!chip)
+		return -ENODEV;
+	if (len < TPM_HEADER_SIZE)
+		return -EIO;
+
+	ret = st33zp24_i2c_request_locality(dev);
+	if (ret < 0)
+		return ret;
+
+	tpm_stat = st33zp24_i2c_status(dev);
+	if ((tpm_stat & TPM_STS_COMMAND_READY) == 0) {
+		st33zp24_i2c_cancel(dev);
+		if (st33zp24_i2c_wait_for_stat(dev, TPM_STS_COMMAND_READY,
+					       chip->timeout_b, &status) < 0) {
+			ret = -ETIME;
+			goto out_err;
+		}
+	}
+
+	for (i = 0; i < len - 1;) {
+		burstcnt = st33zp24_i2c_get_burstcount(dev);
+		if (burstcnt < 0)
+			return burstcnt;
+
+		size = min_t(int, len - i - 1, burstcnt);
+		ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + i, size);
+		if (ret < 0)
+			goto out_err;
+
+		i += size;
+	}
+
+	tpm_stat = st33zp24_i2c_status(dev);
+	if ((tpm_stat & TPM_STS_DATA_EXPECT) == 0) {
+		ret = -EIO;
+		goto out_err;
+	}
+
+	ret = st33zp24_i2c_write(dev, TPM_DATA_FIFO, buf + len - 1, 1);
+	if (ret < 0)
+		goto out_err;
+
+	tpm_stat = st33zp24_i2c_status(dev);
+	if ((tpm_stat & TPM_STS_DATA_EXPECT) != 0) {
+		ret = -EIO;
+		goto out_err;
+	}
+
+	data = TPM_STS_GO;
+	ret = st33zp24_i2c_write(dev, TPM_STS, &data, 1);
+	if (ret < 0)
+		goto out_err;
+
+	return len;
+
+out_err:
+	st33zp24_i2c_cancel(dev);
+	st33zp24_i2c_release_locality(dev);
+
+	return ret;
+}
+
+static int st33zp24_i2c_cleanup(struct udevice *dev)
+{
+	st33zp24_i2c_cancel(dev);
+	/*
+	 * The TPM needs some time to clean up here,
+	 * so we sleep rather than keeping the bus busy
+	 */
+	mdelay(2);
+	st33zp24_i2c_release_locality(dev);
+
+	return 0;
+}
+
+static int st33zp24_i2c_init(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	chip->is_open = 1;
+
+	/* Default timeouts - these could move to the device tree */
+	chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
+	chip->timeout_b = TIS_LONG_TIMEOUT_MS;
+	chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
+	chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
+
+	chip->locality = LOCALITY0;
+
+	/*
+	 * A timeout query to TPM can be placed here.
+	 * Standard timeout values are used so far
+	 */
+
+	return 0;
+}
+
+static int st33zp24_i2c_open(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+	int rc;
+
+	debug("%s: start\n", __func__);
+	if (chip->is_open)
+		return -EBUSY;
+
+	rc = st33zp24_i2c_init(dev);
+	if (rc < 0)
+		chip->is_open = 0;
+
+	return rc;
+}
+
+static int st33zp24_i2c_close(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	if (chip->is_open) {
+		st33zp24_i2c_release_locality(dev);
+		chip->is_open = 0;
+		chip->vend_dev = 0;
+	}
+
+	return 0;
+}
+
+static int st33zp24_i2c_get_desc(struct udevice *dev, char *buf, int size)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	if (size < 50)
+		return -ENOSPC;
+
+	return snprintf(buf, size, "1.2 TPM (%s, chip type %s device-id 0x%x)",
+			chip->is_open ? "open" : "closed",
+			dev->name,
+			chip->vend_dev >> 16);
+}
+
+static const struct tpm_ops st33zp24_i2c_tpm_ops = {
+	.open = st33zp24_i2c_open,
+	.close = st33zp24_i2c_close,
+	.recv = st33zp24_i2c_recv,
+	.send = st33zp24_i2c_send,
+	.cleanup = st33zp24_i2c_cleanup,
+	.get_desc = st33zp24_i2c_get_desc,
+};
+
+static int st33zp24_i2c_probe(struct udevice *dev)
+{
+	struct tpm_chip *chip = dev_get_priv(dev);
+
+	/* Default timeouts */
+	chip->timeout_a = TIS_SHORT_TIMEOUT_MS;
+	chip->timeout_b = TIS_LONG_TIMEOUT_MS;
+	chip->timeout_c = TIS_SHORT_TIMEOUT_MS;
+	chip->timeout_d = TIS_SHORT_TIMEOUT_MS;
+
+	chip->locality = LOCALITY0;
+
+	i2c_set_chip_offset_len(dev, 0);
+
+	debug("ST33ZP24 I2C TPM from STMicroelectronics found\n");
+
+	return 0;
+}
+
+static int st33zp24_i2c_remove(struct udevice *dev)
+{
+	st33zp24_i2c_release_locality(dev);
+
+	return 0;
+}
+
+static const struct udevice_id st33zp24_i2c_ids[] = {
+	{ .compatible = "st,st33zp24-i2c" },
+	{ }
+};
+
+U_BOOT_DRIVER(st33zp24_i2c) = {
+	.name   = "st33zp24-i2c",
+	.id     = UCLASS_TPM,
+	.of_match = of_match_ptr(st33zp24_i2c_ids),
+	.probe  = st33zp24_i2c_probe,
+	.remove = st33zp24_i2c_remove,
+	.ops = &st33zp24_i2c_tpm_ops,
+	.priv_auto_alloc_size = sizeof(struct tpm_chip),
+};