Add driver for Infineon TPMs connected to an I2C bus
The driver has been ported from Coreboot:
https://chromium.googlesource.com/chromiumos/third_party/coreboot/+/chromeos-2013.04/src/drivers/i2c/tpm
d5ab28b5d73c03adcdc0fd4e530b39a7a8989dae
Change-Id: I3600a927496e0ad72f95ab02fe1a2901696c04ee
diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
index ab98f2a..6a82130 100644
--- a/drivers/tpm/Kconfig
+++ b/drivers/tpm/Kconfig
@@ -4,4 +4,9 @@
bool "Enable TPM driver support"
default n
+config TPM_I2C_INFINEON
+ depends on TPM && I2C
+ bool "Enable driver for Infineon TPMs connected to an I2C bus"
+ default n
+
endmenu
diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
index 443ce91..9eb918f 100644
--- a/drivers/tpm/Makefile
+++ b/drivers/tpm/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_TPM) += tis.o
+obj-$(CONFIG_TPM_I2C_INFINEON) += tpm_i2c_infineon.o
diff --git a/drivers/tpm/tpm_i2c_infineon.c b/drivers/tpm/tpm_i2c_infineon.c
new file mode 100644
index 0000000..bd566ae
--- /dev/null
+++ b/drivers/tpm/tpm_i2c_infineon.c
@@ -0,0 +1,584 @@
+/*
+ * Copyright (C) 2011 Infineon Technologies
+ *
+ * Authors:
+ * Peter Huewe <huewe.external@infineon.com>
+ *
+ * Description:
+ * Device driver for TCG/TCPA TPM (trusted platform module).
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * This device driver implements the TPM interface as defined in
+ * the TCG TPM Interface Spec version 1.2, revision 1.0 and the
+ * Infineon I2C Protocol Stack Specification v0.20.
+ *
+ * It is based on the Linux kernel driver tpm.c from Leendert van
+ * Dorn, Dave Safford, Reiner Sailer, and Kyleen Hall.
+ *
+ * Version: 2.1.1
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <asm/byteorder.h>
+#include <common.h>
+#include <stdint.h>
+#include <string.h>
+#include <types.h>
+#include <clock.h>
+#include <driver.h>
+#include <init.h>
+#include <i2c/i2c.h>
+#include "tpm.h"
+
+#define DRIVER_NAME "tpm_i2c_infineon"
+
+#define BIOS_DEBUG KERN_DEBUG
+
+/* Address of the TPM on the I2C bus */
+#define TPM_I2C_ADDR 0x20
+
+/* max. number of iterations after I2C NAK */
+#define MAX_COUNT 3
+
+#define SLEEP_DURATION 60 /* in usec */
+
+/* max. number of iterations after I2C NAK for 'long' commands
+ * we need this especially for sending TPM_READY, since the cleanup after the
+ * transtion to the ready state may take some time, but it is unpredictable
+ * how long it will take.
+ */
+#define MAX_COUNT_LONG 50
+
+#define SLEEP_DURATION_LONG 210 /* in usec */
+
+/* expected value for DIDVID register */
+#define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
+#define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
+
+enum i2c_chip_type {
+ SLB9635,
+ SLB9645,
+ UNKNOWN,
+};
+
+static const char * const chip_name[] = {
+ [SLB9635] = "slb9635tt",
+ [SLB9645] = "slb9645tt",
+ [UNKNOWN] = "unknown/fallback to slb9635",
+};
+
+/* Structure to store I2C TPM specific stuff */
+struct tpm_inf_dev {
+ struct cdev cdev;
+ struct i2c_client *client;
+ uint8_t buf[TPM_BUFSIZE + sizeof(uint8_t)]; // max. buffer size + addr
+ enum i2c_chip_type chip_type;
+};
+
+static struct tpm_inf_dev tpm_dev;
+
+/*
+ * iic_tpm_read() - read from TPM register
+ * @addr: register address to read from
+ * @buffer: provided by caller
+ * @len: number of bytes to read
+ *
+ * Read len bytes from TPM register and put them into
+ * buffer (little-endian format, i.e. first byte is put into buffer[0]).
+ *
+ * NOTE: TPM is big-endian for multi-byte values. Multi-byte
+ * values have to be swapped.
+ *
+ * Return -1 on error, 0 on success.
+ */
+static int iic_tpm_read(uint8_t addr, uint8_t *buffer, size_t len)
+{
+ int rc;
+ int count;
+
+ if (!tpm_dev.client)
+ return -1;
+ if ((tpm_dev.chip_type == SLB9635) || (tpm_dev.chip_type == UNKNOWN)) {
+ /* slb9635 protocol should work in both cases */
+ for (count = 0; count < MAX_COUNT; count++) {
+ rc = (i2c_master_send(tpm_dev.client, &addr, 1) <= 0);
+ if (rc == 0)
+ break; /* success, break to skip sleep */
+
+ udelay(SLEEP_DURATION);
+ }
+
+ if (rc)
+ return -1;
+
+ /* After the TPM has successfully received the register address
+ * it needs some time, thus we're sleeping here again, before
+ * retrieving the data
+ */
+ for (count = 0; count < MAX_COUNT; count++) {
+ udelay(SLEEP_DURATION);
+ rc = (i2c_master_recv(tpm_dev.client, buffer, len) <= 0);
+ if (rc == 0)
+ break; /* success, break to skip sleep */
+
+ }
+ } else {
+ /* use a combined read for newer chips
+ * unfortunately the smbus functions are not suitable due to
+ * the 32 byte limit of the smbus.
+ * retries should usually not be needed, but are kept just to
+ * be safe on the safe side.
+ */
+ struct i2c_msg msgs[] = {
+ {
+ .addr = tpm_dev.client->addr,
+ .flags = 0,
+ .buf = &addr,
+ .len = 1,
+ },
+ {
+ .addr = tpm_dev.client->addr,
+ .flags = I2C_M_RD,
+ .buf = buffer,
+ .len = len,
+ },
+ };
+
+ for (count = 0; count < MAX_COUNT; count++) {
+ rc = (i2c_transfer(tpm_dev.client->adapter, msgs, 2) != 2);
+ if (rc == 0)
+ break; /* break here to skip sleep */
+ udelay(SLEEP_DURATION);
+ }
+ }
+
+ /* take care of 'guard time' */
+ udelay(SLEEP_DURATION);
+ if (rc)
+ return -1;
+
+ return 0;
+}
+
+static int iic_tpm_write_generic(uint8_t addr, uint8_t *buffer, size_t len,
+ unsigned int sleep_time,
+ uint8_t max_count)
+{
+ int rc = 0;
+ int count;
+
+ if (len > TPM_BUFSIZE) {
+ printk(BIOS_DEBUG "%s: Length %zd is too large\n", __func__, len);
+ return -1;
+ }
+
+ /* prepare send buffer */
+ tpm_dev.buf[0] = addr;
+ memcpy(&(tpm_dev.buf[1]), buffer, len);
+
+ if (!tpm_dev.client)
+ return -1;
+ for (count = 0; count < max_count; count++) {
+ rc = (i2c_master_send(tpm_dev.client,
+ tpm_dev.buf, len + 1) <= 0);
+ if (rc == 0)
+ break; /* success, break to skip sleep */
+
+ udelay(sleep_time);
+ }
+
+ /* take care of 'guard time' */
+ udelay(SLEEP_DURATION);
+ if (rc)
+ return -1;
+
+ return 0;
+}
+
+/*
+ * iic_tpm_write() - write to TPM register
+ * @addr: register address to write to
+ * @buffer: containing data to be written
+ * @len: number of bytes to write
+ *
+ * Write len bytes from provided buffer to TPM register (little
+ * endian format, i.e. buffer[0] is written as first byte).
+ *
+ * NOTE: TPM is big-endian for multi-byte values. Multi-byte
+ * values have to be swapped.
+ *
+ * NOTE: use this function instead of the iic_tpm_write_generic function.
+ *
+ * Return -EIO on error, 0 on success
+ */
+static int iic_tpm_write(uint8_t addr, uint8_t *buffer, size_t len)
+{
+ return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION,
+ MAX_COUNT);
+}
+
+/*
+ * This function is needed especially for the cleanup situation after
+ * sending TPM_READY
+ * */
+static int iic_tpm_write_long(uint8_t addr, uint8_t *buffer, size_t len)
+{
+ return iic_tpm_write_generic(addr, buffer, len, SLEEP_DURATION_LONG,
+ MAX_COUNT_LONG);
+}
+
+#define TPM_HEADER_SIZE 10
+
+enum tis_access {
+ TPM_ACCESS_VALID = 0x80,
+ TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
+ TPM_ACCESS_REQUEST_PENDING = 0x04,
+ TPM_ACCESS_REQUEST_USE = 0x02,
+};
+
+enum tis_status {
+ TPM_STS_VALID = 0x80,
+ TPM_STS_COMMAND_READY = 0x40,
+ TPM_STS_GO = 0x20,
+ TPM_STS_DATA_AVAIL = 0x10,
+ TPM_STS_DATA_EXPECT = 0x08,
+};
+
+#define TPM_ACCESS(l) (0x0000 | ((l) << 4))
+#define TPM_STS(l) (0x0001 | ((l) << 4))
+#define TPM_DATA_FIFO(l) (0x0005 | ((l) << 4))
+#define TPM_DID_VID(l) (0x0006 | ((l) << 4))
+
+static int check_locality(struct tpm_chip *chip, int loc)
+{
+ uint8_t buf;
+
+ if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
+ return -1;
+
+ if ((buf & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
+ (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
+ chip->vendor.locality = loc;
+ return loc;
+ }
+
+ return -1;
+}
+
+static void release_locality(struct tpm_chip *chip, int loc, int force)
+{
+ uint8_t buf;
+ if (iic_tpm_read(TPM_ACCESS(loc), &buf, 1) < 0)
+ return;
+
+ if (force || (buf & (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) ==
+ (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) {
+ buf = TPM_ACCESS_ACTIVE_LOCALITY;
+ iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
+ }
+}
+
+static int request_locality(struct tpm_chip *chip, int loc)
+{
+ uint8_t buf = TPM_ACCESS_REQUEST_USE;
+
+ if (check_locality(chip, loc) >= 0)
+ return loc; /* we already have the locality */
+
+ iic_tpm_write(TPM_ACCESS(loc), &buf, 1);
+
+ /* wait for burstcount */
+ int timeout = 2 * 1000; /* 2s timeout */
+ while (timeout) {
+ if (check_locality(chip, loc) >= 0)
+ return loc;
+ mdelay(TPM_TIMEOUT);
+ timeout--;
+ }
+
+ return -1;
+}
+
+static uint8_t tpm_tis_i2c_status(struct tpm_chip *chip)
+{
+ /* NOTE: Since I2C read may fail, return 0 in this case --> time-out */
+ uint8_t buf;
+ if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
+ return 0;
+ else
+ return buf;
+}
+
+static void tpm_tis_i2c_ready(struct tpm_chip *chip)
+{
+ /* this causes the current command to be aborted */
+ uint8_t buf = TPM_STS_COMMAND_READY;
+ iic_tpm_write_long(TPM_STS(chip->vendor.locality), &buf, 1);
+}
+
+static ssize_t get_burstcount(struct tpm_chip *chip)
+{
+ ssize_t burstcnt;
+ uint8_t buf[3];
+
+ /* wait for burstcount */
+ int timeout = 2 * 1000; /* 2s timeout */
+ while (timeout) {
+ /* Note: STS is little endian */
+ if (iic_tpm_read(TPM_STS(chip->vendor.locality) + 1, buf, 3) < 0)
+ burstcnt = 0;
+ else
+ burstcnt = (buf[2] << 16) + (buf[1] << 8) + buf[0];
+
+ if (burstcnt)
+ return burstcnt;
+ mdelay(TPM_TIMEOUT);
+ timeout--;
+ }
+ return -1;
+}
+
+static int wait_for_stat(struct tpm_chip *chip, uint8_t mask, int *status)
+{
+ unsigned long timeout = 2 * 1024;
+ while (timeout) {
+ *status = tpm_tis_i2c_status(chip);
+ if ((*status & mask) == mask)
+ return 0;
+ mdelay(TPM_TIMEOUT);
+ timeout--;
+ }
+
+ return -1;
+}
+
+static int recv_data(struct tpm_chip *chip, uint8_t *buf, size_t count)
+{
+ size_t size = 0;
+
+ while (size < count) {
+ ssize_t burstcnt = get_burstcount(chip);
+ int rc;
+
+ /* burstcount < 0 = TPM is busy */
+ if (burstcnt < 0)
+ return burstcnt;
+
+ /* limit received data to max. left */
+ if (burstcnt > (count - size))
+ burstcnt = count - size;
+
+ rc = iic_tpm_read(TPM_DATA_FIFO(chip->vendor.locality),
+ &(buf[size]),
+ burstcnt);
+ if (rc == 0)
+ size += burstcnt;
+
+ }
+ return size;
+}
+
+static int tpm_tis_i2c_recv(struct tpm_chip *chip, uint8_t *buf, size_t count)
+{
+ int size = 0;
+ uint32_t expected;
+ int status;
+
+ if (count < TPM_HEADER_SIZE) {
+ size = -1;
+ goto out;
+ }
+
+ /* read first 10 bytes, including tag, paramsize, and result */
+ size = recv_data(chip, buf, TPM_HEADER_SIZE);
+ if (size < TPM_HEADER_SIZE) {
+ printk(BIOS_DEBUG "tpm_tis_i2c_recv: Unable to read header\n");
+ goto out;
+ }
+
+ memcpy(&expected, buf + TPM_RSP_SIZE_BYTE, sizeof(expected));
+ expected = be32_to_cpu(expected);
+ if ((size_t)expected > count) {
+ size = -1;
+ goto out;
+ }
+
+ size += recv_data(chip, &buf[TPM_HEADER_SIZE],
+ expected - TPM_HEADER_SIZE);
+ if (size < expected) {
+ printk(BIOS_DEBUG "tpm_tis_i2c_recv: Unable to "
+ "read remainder of result\n");
+ size = -1;
+ goto out;
+ }
+
+ wait_for_stat(chip, TPM_STS_VALID, &status);
+ if (status & TPM_STS_DATA_AVAIL) { /* retry? */
+ printk(BIOS_DEBUG "tpm_tis_i2c_recv: Error left over data\n");
+ size = -1;
+ goto out;
+ }
+
+out:
+ tpm_tis_i2c_ready(chip);
+
+ return size;
+}
+
+static int tpm_tis_i2c_send(struct tpm_chip *chip, uint8_t *buf, size_t len)
+{
+ int status;
+ size_t count = 0;
+ uint8_t sts = TPM_STS_GO;
+
+ if (len > TPM_BUFSIZE)
+ return -1; /* command is too long for our TPM, sorry */
+
+ status = tpm_tis_i2c_status(chip);
+ if ((status & TPM_STS_COMMAND_READY) == 0) {
+ tpm_tis_i2c_ready(chip);
+ if (wait_for_stat(chip, TPM_STS_COMMAND_READY, &status) < 0)
+ goto out_err;
+ }
+
+ while (count < len - 1) {
+ ssize_t burstcnt = get_burstcount(chip);
+
+ /* burstcount < 0 = TPM is busy */
+ if (burstcnt < 0)
+ return burstcnt;
+
+ if (burstcnt > (len-1-count))
+ burstcnt = len-1-count;
+
+#ifdef CONFIG_TPM_I2C_BURST_LIMITATION
+ if (burstcnt > CONFIG_TPM_I2C_BURST_LIMITATION)
+ burstcnt = CONFIG_TPM_I2C_BURST_LIMITATION;
+#endif /* CONFIG_TPM_I2C_BURST_LIMITATION */
+
+ if (iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
+ &(buf[count]), burstcnt) == 0)
+ count += burstcnt;
+
+ wait_for_stat(chip, TPM_STS_VALID, &status);
+ if ((status & TPM_STS_DATA_EXPECT) == 0)
+ goto out_err;
+ }
+
+ /* write last byte */
+ iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality), &(buf[count]), 1);
+
+ wait_for_stat(chip, TPM_STS_VALID, &status);
+ if ((status & TPM_STS_DATA_EXPECT) != 0)
+ goto out_err;
+
+ /* go and do it */
+ iic_tpm_write(TPM_STS(chip->vendor.locality), &sts, 1);
+
+ return len;
+
+out_err:
+ tpm_tis_i2c_ready(chip);
+
+ return -1;
+}
+
+static struct tpm_vendor_specific tpm_tis_i2c = {
+ .status = tpm_tis_i2c_status,
+ .recv = tpm_tis_i2c_recv,
+ .send = tpm_tis_i2c_send,
+ .cancel = tpm_tis_i2c_ready,
+ .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ .req_canceled = TPM_STS_COMMAND_READY,
+};
+
+/* Initialization of I2C TPM */
+
+static int tpm_probe(struct device_d *dev)
+{
+ uint32_t vendor;
+ struct tpm_chip *chip;
+ extern struct tpm_chip g_chip;
+
+ chip = &g_chip;
+ memcpy(&chip->vendor, &tpm_tis_i2c, sizeof(struct tpm_vendor_specific));
+
+ tpm_dev.cdev.name = DRIVER_NAME;
+ tpm_dev.client = to_i2c_client(dev);
+ tpm_dev.cdev.size = 1024; // ?
+ tpm_dev.cdev.dev = dev;
+
+ /* Disable interrupts (not supported) */
+ chip->vendor.irq = 0;
+
+ if (request_locality(chip, 0) != 0)
+ goto out_err;
+
+ /* Read four bytes from DID_VID register */
+ if (iic_tpm_read(TPM_DID_VID(0), (uint8_t *)&vendor, 4) < 0)
+ goto out_release;
+
+ if (vendor == TPM_TIS_I2C_DID_VID_9645) {
+ tpm_dev.chip_type = SLB9645;
+ } else if (be32_to_cpu(vendor) == TPM_TIS_I2C_DID_VID_9635) {
+ tpm_dev.chip_type = SLB9635;
+ } else {
+ printk(BIOS_DEBUG "Vendor ID 0x%08x not recognized.\n", vendor);
+ goto out_release;
+ }
+
+ printk(BIOS_DEBUG "1.2 TPM (chip type %s device-id 0x%X)\n",
+ chip_name[tpm_dev.chip_type], vendor >> 16);
+
+ /*
+ * A timeout query to TPM can be placed here.
+ * Standard timeout values are used so far
+ */
+
+ devfs_create(&tpm_dev.cdev);
+ chip->is_open = 1;
+
+ return 0;
+
+out_release:
+ release_locality(chip, 0, 1);
+
+out_err:
+ return -1;
+}
+
+void tpm_vendor_cleanup(struct tpm_chip *chip)
+{
+ release_locality(chip, chip->vendor.locality, 1);
+}
+
+static struct driver_d tpm_i2c_infineon_driver = {
+ .name = DRIVER_NAME,
+ .probe = tpm_probe,
+};
+
+static int tpm_i2c_infineon_init(void)
+{
+ register_driver(&tpm_i2c_infineon_driver);
+ return 0;
+}
+
+device_initcall(tpm_i2c_infineon_init);
