Add Infineon v05 TPM driver

drivers/tpm/slb9635_i2c/tpm_tis_i2c.c

+/*
+ * 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 <common.h>
+#include <i2c.h>
+#include <linux/types.h>
+
+#include "compatibility.h"
+#include "tpm.h"
+
+/* max. buffer size supported by our tpm */
+#ifdef TPM_BUFSIZE
+#undef TPM_BUFSIZE
+#endif
+#define TPM_BUFSIZE 1260
+/* 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 0x000b15d1L
+
+/* Structure to store I2C TPM specific stuff */
+struct tpm_inf_dev {
+        uint addr;
+        u8 buf[TPM_BUFSIZE + sizeof(u8)];       /* max. buffer size + addr */
+};
+
+static struct tpm_inf_dev tpm_dev = {
+        .addr = TPM_I2C_ADDR
+};
+
+/* I2C Read/Write Functions from U-Boot
+* Unfortunately we have to use these functions directly, due to the wakeup
+* behaviour of the tpm
+*/
+extern int i2c_read_data(uchar chip, uchar *buffer, int len);
+extern int i2c_write_data(uchar chip, uchar *buffer, int len);
+
+/*
+ * 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 -EIO on error, 0 on success.
+ */
+int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
+{
+        int rc;
+        int count;
+        uint myaddr = addr;
+        /* we have to use uint here, uchar hangs the board */
+
+        for (count = 0; count < MAX_COUNT; count++) {
+                rc = i2c_write_data(tpm_dev.addr, (uchar *) &myaddr, 1);
+                if (rc == 0)
+                        break; /*success, break to skip sleep*/
+
+                udelay(SLEEP_DURATION);
+        }
+
+        if (rc)
+                return -rc;
+
+        /* 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_read_data(tpm_dev.addr, buffer, len);
+                if (rc == 0)
+                        break; /*success, break to skip sleep*/
+
+        }
+
+        if (rc)
+                return -rc;
+
+        return 0;
+}
+
+static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
+                                unsigned int sleep_time,
+                                u8 max_count)
+{
+        int rc = 0;
+        int count;
+
+        /* prepare send buffer */
+        tpm_dev.buf[0] = addr;
+        memcpy(&(tpm_dev.buf[1]), buffer, len);
+
+        for (count = 0; count < max_count; count++) {
+                rc = i2c_write_data(tpm_dev.addr, tpm_dev.buf, len + 1);
+                if (rc == 0)
+                        break; /*success, break to skip sleep*/
+
+                udelay(sleep_time);
+        }
+
+        if (rc)
+                return -rc;
+
+        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(u8 addr, u8 *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(u8 addr, u8 *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,
+};
+
+enum tis_defaults {
+        TIS_SHORT_TIMEOUT = 750,        /* ms */
+        TIS_LONG_TIMEOUT = 2000,        /* 2 sec */
+};
+
+#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)
+{
+        u8 buf;
+        int rc;
+
+        rc = iic_tpm_read(TPM_ACCESS(loc), &buf, 1);
+        if (rc < 0)
+                return rc;
+
+        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)
+{
+        u8 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)
+{
+        unsigned long start, stop;
+        u8 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 */
+        start = get_timer(0);
+        stop = chip->vendor.timeout_a;
+        do {
+                if (check_locality(chip, loc) >= 0)
+                        return loc;
+                msleep(TPM_TIMEOUT);
+        } while (get_timer(start) < stop);
+
+        return -1;
+}
+
+static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
+{
+        /* NOTE: since i2c read may fail, return 0 in this case --> time-out */
+        u8 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 */
+        u8 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)
+{
+        unsigned long start, stop;
+        ssize_t burstcnt;
+        u8 buf[3];
+
+        /* wait for burstcount */
+        /* which timeout value, spec has 2 answers (c & d) */
+        start = get_timer(0);
+        stop = chip->vendor.timeout_d;
+        do {
+                /* 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;
+                msleep(TPM_TIMEOUT);
+        } while (get_timer(start) < stop);
+        return -EBUSY;
+}
+
+static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
+                        int *status)
+{
+        unsigned long start, stop;
+
+        /* check current status */
+        *status = tpm_tis_i2c_status(chip);
+        if ((*status & mask) == mask)
+                return 0;
+
+        start = get_timer(0);
+        stop = timeout;
+        do {
+                msleep(TPM_TIMEOUT);
+                *status = tpm_tis_i2c_status(chip);
+                if ((*status & mask) == mask)
+                        return 0;
+
+        } while (get_timer(start) < stop);
+
+        return -ETIME;
+}
+
+static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+        size_t size = 0;
+        ssize_t burstcnt;
+        int rc;
+
+        while (size < count) {
+                burstcnt = get_burstcount(chip);
+
+                /* 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, u8 *buf, size_t count)
+{
+        int size = 0;
+        int expected, status;
+
+        if (count < TPM_HEADER_SIZE) {
+                size = -EIO;
+                goto out;
+        }
+
+        /* read first 10 bytes, including tag, paramsize, and result */
+        size = recv_data(chip, buf, TPM_HEADER_SIZE);
+        if (size < TPM_HEADER_SIZE) {
+                dev_err(chip->dev, "Unable to read header\n");
+                goto out;
+        }
+
+        expected = get_unaligned_be32(buf + TPM_RSP_SIZE_BYTE);
+        if ((size_t)expected > count) {
+                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;
+        }
+
+        wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &status);
+        if (status & TPM_STS_DATA_AVAIL) {      /* retry? */
+                dev_err(chip->dev, "Error left over data\n");
+                size = -EIO;
+                goto out;
+        }
+
+out:
+        tpm_tis_i2c_ready(chip);
+        /* The TPM needs some time to clean up here,
+         * so we sleep rather than keeping the bus busy
+         */
+        msleep(2);
+        release_locality(chip, chip->vendor.locality, 0);
+
+        return size;
+}
+
+static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+        int rc, status;
+        ssize_t burstcnt;
+        size_t count = 0;
+        u8 sts = TPM_STS_GO;
+
+        if (len > TPM_BUFSIZE)
+                return -E2BIG; /* command is too long for our tpm, sorry */
+
+        if (request_locality(chip, 0) < 0)
+                return -EBUSY;
+
+        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,
+                     chip->vendor.timeout_b, &status) < 0) {
+                        rc = -ETIME;
+                        goto out_err;
+                }
+        }
+
+        while (count < len - 1) {
+                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 */
+
+                rc = iic_tpm_write(TPM_DATA_FIFO(chip->vendor.locality),
+                                   &(buf[count]), burstcnt);
+                if (rc == 0)
+                        count += burstcnt;
+
+                wait_for_stat(chip, TPM_STS_VALID,
+                                chip->vendor.timeout_c, &status);
+
+                if ((status & TPM_STS_DATA_EXPECT) == 0) {
+                        rc = -EIO;
+                        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, chip->vendor.timeout_c, &status);
+        if ((status & TPM_STS_DATA_EXPECT) != 0) {
+                rc = -EIO;
+                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);
+        /* The TPM needs some time to clean up here,
+         * so we sleep rather than keeping the bus busy
+         */
+        msleep(2);
+        release_locality(chip, chip->vendor.locality, 0);
+
+        return rc;
+}
+
+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,
+};
+
+/* initialisation of i2c tpm */
+
+
+int tpm_vendor_init(uint32_t dev_addr)
+{
+        u32 vendor;
+        uint old_addr;
+        int rc = 0;
+        struct tpm_chip *chip;
+
+        old_addr = tpm_dev.addr;
+        if (dev_addr != 0)
+                tpm_dev.addr = dev_addr;
+
+        chip = tpm_register_hardware(&tpm_tis_i2c);
+        if (chip < 0) {
+                rc = -ENODEV;
+                goto out_err;
+        }
+
+        /* Disable interrupts (not supported) */
+        chip->vendor.irq = 0;
+
+        /* Default timeouts */
+        chip->vendor.timeout_a = TIS_SHORT_TIMEOUT;
+        chip->vendor.timeout_b = TIS_LONG_TIMEOUT;
+        chip->vendor.timeout_c = TIS_SHORT_TIMEOUT;
+        chip->vendor.timeout_d = TIS_SHORT_TIMEOUT;
+
+        if (request_locality(chip, 0) != 0) {
+                rc = -ENODEV;
+                goto out_err;
+        }
+
+        /* read four bytes from DID_VID register */
+        if (iic_tpm_read(TPM_DID_VID(0), (uchar *)&vendor, 4) < 0) {
+                rc = -EIO;
+                goto out_release;
+        }
+
+        /* create DID_VID register value, after swapping to little-endian */
+        vendor = be32_to_cpu(vendor);
+
+        if (vendor != TPM_TIS_I2C_DID_VID) {
+                rc = -ENODEV;
+                goto out_release;
+        }
+
+        dev_info(dev, "1.2 TPM (device-id 0x%X)\n", vendor >> 16);
+
+        /*
+         * A timeout query to TPM can be placed here.
+         * Standard timeout values are used so far
+         */
+
+        return 0;
+
+out_release:
+        release_locality(chip, 0, 1);
+
+out_err:
+        tpm_dev.addr = old_addr;
+        return rc;
+}
+
+void tpm_vendor_cleanup(struct tpm_chip *chip)
+{
+        release_locality(chip, chip->vendor.locality, 1);
+}