]> git.kernelconcepts.de Git - karo-tx-uboot.git/blobdiff - drivers/tpm/tpm_tis_i2c.c
tpm: tpm_tis_i2c: Drop unnecessary methods
[karo-tx-uboot.git] / drivers / tpm / tpm_tis_i2c.c
index ee4dfeae445bd7d9b398ce59086e54ead4ec20ff..6a3991f9870ea72f2bf089d8638d7f2e267db731 100644 (file)
  *
  * 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
+ * SPDX-License-Identifier:    GPL-2.0
  */
 
 #include <common.h>
 #include <linux/types.h>
 #include <linux/unaligned/be_byteshift.h>
 
-#include "tpm_private.h"
+#include "tpm_tis_i2c.h"
 
 DECLARE_GLOBAL_DATA_PTR;
 
-/* Address of the TPM on the I2C bus */
-#define TPM_I2C_ADDR           0x20
-
 /* Max buffer size supported by our tpm */
 #define TPM_DEV_BUFSIZE                1260
 
@@ -73,13 +54,6 @@ DECLARE_GLOBAL_DATA_PTR;
 
 #define TPM_HEADER_SIZE                10
 
-/*
- * Expected value for DIDVID register
- *
- * The only device the system knows about at this moment is Infineon slb9635.
- */
-#define TPM_TIS_I2C_DID_VID    0x000b15d1L
-
 enum tis_access {
        TPM_ACCESS_VALID                = 0x80,
        TPM_ACCESS_ACTIVE_LOCALITY      = 0x20,
@@ -121,23 +95,311 @@ static const char * const chip_name[] = {
 #define        TPM_DATA_FIFO(l)                (0x0005 | ((l) << 4))
 #define        TPM_DID_VID(l)                  (0x0006 | ((l) << 4))
 
+enum tpm_duration {
+       TPM_SHORT = 0,
+       TPM_MEDIUM = 1,
+       TPM_LONG = 2,
+       TPM_UNDEFINED,
+};
+
+/* Extended error numbers from linux (see errno.h) */
+#define ECANCELED      125     /* Operation Canceled */
+
+/* Timer frequency. Corresponds to msec timer resolution*/
+#define HZ             1000
+
+#define TPM_MAX_ORDINAL                        243
+#define TPM_MAX_PROTECTED_ORDINAL      12
+#define TPM_PROTECTED_ORDINAL_MASK     0xFF
+
+#define TPM_CMD_COUNT_BYTE     2
+#define TPM_CMD_ORDINAL_BYTE   6
+
+/*
+ * Array with one entry per ordinal defining the maximum amount
+ * of time the chip could take to return the result.  The ordinal
+ * designation of short, medium or long is defined in a table in
+ * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
+ * values of the SHORT, MEDIUM, and LONG durations are retrieved
+ * from the chip during initialization with a call to tpm_get_timeouts.
+ */
+static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
+       TPM_UNDEFINED,          /* 0 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 5 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 10 */
+       TPM_SHORT,
+};
+
+static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
+       TPM_UNDEFINED,          /* 0 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 5 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 10 */
+       TPM_SHORT,
+       TPM_MEDIUM,
+       TPM_LONG,
+       TPM_LONG,
+       TPM_MEDIUM,             /* 15 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_MEDIUM,
+       TPM_LONG,
+       TPM_SHORT,              /* 20 */
+       TPM_SHORT,
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_SHORT,              /* 25 */
+       TPM_SHORT,
+       TPM_MEDIUM,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_MEDIUM,             /* 30 */
+       TPM_LONG,
+       TPM_MEDIUM,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,              /* 35 */
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_MEDIUM,             /* 40 */
+       TPM_LONG,
+       TPM_MEDIUM,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,              /* 45 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_LONG,
+       TPM_MEDIUM,             /* 50 */
+       TPM_MEDIUM,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 55 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_MEDIUM,             /* 60 */
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_MEDIUM,             /* 65 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 70 */
+       TPM_SHORT,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 75 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_LONG,               /* 80 */
+       TPM_UNDEFINED,
+       TPM_MEDIUM,
+       TPM_LONG,
+       TPM_SHORT,
+       TPM_UNDEFINED,          /* 85 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 90 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_UNDEFINED,          /* 95 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_MEDIUM,             /* 100 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 105 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 110 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,              /* 115 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_LONG,               /* 120 */
+       TPM_LONG,
+       TPM_MEDIUM,
+       TPM_UNDEFINED,
+       TPM_SHORT,
+       TPM_SHORT,              /* 125 */
+       TPM_SHORT,
+       TPM_LONG,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,              /* 130 */
+       TPM_MEDIUM,
+       TPM_UNDEFINED,
+       TPM_SHORT,
+       TPM_MEDIUM,
+       TPM_UNDEFINED,          /* 135 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 140 */
+       TPM_SHORT,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 145 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 150 */
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_UNDEFINED,          /* 155 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 160 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 165 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_LONG,               /* 170 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 175 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_MEDIUM,             /* 180 */
+       TPM_SHORT,
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_MEDIUM,             /* 185 */
+       TPM_SHORT,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 190 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 195 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 200 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,
+       TPM_SHORT,              /* 205 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_MEDIUM,             /* 210 */
+       TPM_UNDEFINED,
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_MEDIUM,
+       TPM_UNDEFINED,          /* 215 */
+       TPM_MEDIUM,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,
+       TPM_SHORT,              /* 220 */
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_SHORT,
+       TPM_UNDEFINED,          /* 225 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 230 */
+       TPM_LONG,
+       TPM_MEDIUM,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,          /* 235 */
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_UNDEFINED,
+       TPM_SHORT,              /* 240 */
+       TPM_UNDEFINED,
+       TPM_MEDIUM,
+};
+
+/* TPM configuration */
+struct tpm {
+       struct udevice *dev;
+       char inited;
+} tpm;
+
+/* Global structure for tpm chip data */
+static struct tpm_chip g_chip;
+
 /* Structure to store I2C TPM specific stuff */
 struct tpm_dev {
-#ifdef CONFIG_DM_I2C
        struct udevice *dev;
-#else
-       uint addr;
-#endif
        u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)];  /* Max buffer size + addr */
        enum i2c_chip_type chip_type;
 };
 
-static struct tpm_dev tpm_dev = {
-#ifndef CONFIG_DM_I2C
-       .addr = TPM_I2C_ADDR
-#endif
-};
-
 static struct tpm_dev tpm_dev;
 
 /*
@@ -163,12 +425,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
        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++) {
-#ifdef CONFIG_DM_I2C
                        rc = dm_i2c_write(tpm_dev.dev, 0, (uchar *)&addrbuf, 1);
-#else
-                       rc = i2c_write(tpm_dev.addr, 0, 0,
-                                      (uchar *)&addrbuf, 1);
-#endif
                        if (rc == 0)
                                break;  /* Success, break to skip sleep */
                        udelay(SLEEP_DURATION);
@@ -182,11 +439,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
                 */
                for (count = 0; count < MAX_COUNT; count++) {
                        udelay(SLEEP_DURATION);
-#ifdef CONFIG_DM_I2C
                        rc = dm_i2c_read(tpm_dev.dev, 0, buffer, len);
-#else
-                       rc = i2c_read(tpm_dev.addr, 0, 0, buffer, len);
-#endif
                        if (rc == 0)
                                break;  /* success, break to skip sleep */
                }
@@ -199,11 +452,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
                 * be safe on the safe side.
                 */
                for (count = 0; count < MAX_COUNT; count++) {
-#ifdef CONFIG_DM_I2C
                        rc = dm_i2c_read(tpm_dev.dev, addr, buffer, len);
-#else
-                       rc = i2c_read(tpm_dev.addr, addr, 1, buffer, len);
-#endif
                        if (rc == 0)
                                break;  /* break here to skip sleep */
                        udelay(SLEEP_DURATION);
@@ -224,20 +473,8 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
        int rc = 0;
        int count;
 
-       /* Prepare send buffer */
-#ifndef CONFIG_DM_I2C
-       tpm_dev.buf[0] = addr;
-       memcpy(&(tpm_dev.buf[1]), buffer, len);
-       buffer = tpm_dev.buf;
-       len++;
-#endif
-
        for (count = 0; count < max_count; count++) {
-#ifdef CONFIG_DM_I2C
                rc = dm_i2c_write(tpm_dev.dev, addr, buffer, len);
-#else
-               rc = i2c_write(tpm_dev.addr, 0, 0, buffer, len);
-#endif
                if (rc == 0)
                        break;  /* Success, break to skip sleep */
                udelay(sleep_time);
@@ -573,10 +810,6 @@ out_err:
 }
 
 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,
@@ -585,7 +818,7 @@ static struct tpm_vendor_specific tpm_tis_i2c = {
 
 static enum i2c_chip_type tpm_vendor_chip_type(void)
 {
-#ifdef CONFIG_OF_CONTROL
+#if CONFIG_IS_ENABLED(OF_CONTROL)
        const void *blob = gd->fdt_blob;
 
        if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
@@ -597,12 +830,13 @@ static enum i2c_chip_type tpm_vendor_chip_type(void)
        return UNKNOWN;
 }
 
-static int tpm_vendor_init_common(void)
+int tpm_vendor_init(struct udevice *dev)
 {
        struct tpm_chip *chip;
        u32 vendor;
        u32 expected_did_vid;
 
+       tpm_dev.dev = dev;
        tpm_dev.chip_type = tpm_vendor_chip_type();
 
        chip = tpm_register_hardware(&tpm_tis_i2c);
@@ -651,33 +885,255 @@ static int tpm_vendor_init_common(void)
        return 0;
 }
 
-#ifdef CONFIG_DM_I2C
-/* Initialisation of i2c tpm */
-int tpm_vendor_init_dev(struct udevice *dev)
+void tpm_vendor_cleanup(struct tpm_chip *chip)
 {
-       tpm_dev.dev = dev;
-       return tpm_vendor_init_common();
+       release_locality(chip, chip->vendor.locality, 1);
 }
-#else
-/* Initialisation of i2c tpm */
-int tpm_vendor_init(uint32_t dev_addr)
+
+/* Returns max number of milliseconds to wait */
+static unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
+               u32 ordinal)
 {
-       uint old_addr;
-       int rc = 0;
+       int duration_idx = TPM_UNDEFINED;
+       int duration = 0;
+
+       if (ordinal < TPM_MAX_ORDINAL) {
+               duration_idx = tpm_ordinal_duration[ordinal];
+       } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
+                       TPM_MAX_PROTECTED_ORDINAL) {
+               duration_idx = tpm_protected_ordinal_duration[
+                               ordinal & TPM_PROTECTED_ORDINAL_MASK];
+       }
 
-       old_addr = tpm_dev.addr;
-       if (dev_addr != 0)
-               tpm_dev.addr = dev_addr;
+       if (duration_idx != TPM_UNDEFINED)
+               duration = chip->vendor.duration[duration_idx];
 
-       rc = tpm_vendor_init_common();
-       if (rc)
-               tpm_dev.addr = old_addr;
+       if (duration <= 0)
+               return 2 * 60 * HZ; /* Two minutes timeout */
+       else
+               return duration;
+}
+
+static ssize_t tpm_transmit(const unsigned char *buf, size_t bufsiz)
+{
+       int rc;
+       u32 count, ordinal;
+       unsigned long start, stop;
+
+       struct tpm_chip *chip = &g_chip;
 
+       /* switch endianess: big->little */
+       count = get_unaligned_be32(buf + TPM_CMD_COUNT_BYTE);
+       ordinal = get_unaligned_be32(buf + TPM_CMD_ORDINAL_BYTE);
+
+       if (count == 0) {
+               error("no data\n");
+               return -ENODATA;
+       }
+       if (count > bufsiz) {
+               error("invalid count value %x %zx\n", count, bufsiz);
+               return -E2BIG;
+       }
+
+       debug("Calling send\n");
+       rc = tpm_tis_i2c_send(chip, (u8 *)buf, count);
+       debug("   ... done calling send\n");
+       if (rc < 0) {
+               error("tpm_transmit: tpm_send: error %d\n", rc);
+               goto out;
+       }
+
+       if (chip->vendor.irq)
+               goto out_recv;
+
+       start = get_timer(0);
+       stop = tpm_calc_ordinal_duration(chip, ordinal);
+       do {
+               debug("waiting for status... %ld %ld\n", start, stop);
+               u8 status = tpm_tis_i2c_status(chip);
+               if ((status & chip->vendor.req_complete_mask) ==
+                   chip->vendor.req_complete_val) {
+                       debug("...got it;\n");
+                       goto out_recv;
+               }
+
+               if (status == chip->vendor.req_canceled) {
+                       error("Operation Canceled\n");
+                       rc = -ECANCELED;
+                       goto out;
+               }
+               udelay(TPM_TIMEOUT * 1000);
+       } while (get_timer(start) < stop);
+
+       tpm_tis_i2c_ready(chip);
+       error("Operation Timed out\n");
+       rc = -ETIME;
+       goto out;
+
+out_recv:
+       debug("out_recv: reading response...\n");
+       rc = tpm_tis_i2c_recv(chip, (u8 *)buf, TPM_BUFSIZE);
+       if (rc < 0)
+               error("tpm_transmit: tpm_recv: error %d\n", rc);
+
+out:
        return rc;
 }
-#endif
 
-void tpm_vendor_cleanup(struct tpm_chip *chip)
+static int tpm_open_dev(struct udevice *dev)
 {
-       release_locality(chip, chip->vendor.locality, 1);
+       int rc;
+
+       debug("%s: start\n", __func__);
+       if (g_chip.is_open)
+               return -EBUSY;
+       rc = tpm_vendor_init(dev);
+       if (rc < 0)
+               g_chip.is_open = 0;
+       return rc;
+}
+
+static void tpm_close(void)
+{
+       if (g_chip.is_open) {
+               tpm_vendor_cleanup(&g_chip);
+               g_chip.is_open = 0;
+       }
+}
+
+/**
+ * Decode TPM configuration.
+ *
+ * @param dev  Returns a configuration of TPM device
+ * @return 0 if ok, -1 on error
+ */
+static int tpm_decode_config(struct tpm *dev)
+{
+       const void *blob = gd->fdt_blob;
+       struct udevice *bus;
+       int chip_addr;
+       int parent;
+       int node;
+       int ret;
+
+       node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
+       if (node < 0) {
+               node = fdtdec_next_compatible(blob, 0,
+                               COMPAT_INFINEON_SLB9645_TPM);
+       }
+       if (node < 0) {
+               debug("%s: Node not found\n", __func__);
+               return -1;
+       }
+       parent = fdt_parent_offset(blob, node);
+       if (parent < 0) {
+               debug("%s: Cannot find node parent\n", __func__);
+               return -1;
+       }
+
+       /*
+        * TODO(sjg@chromium.org): Remove this when driver model supports
+        * TPMs
+        */
+       ret = uclass_get_device_by_of_offset(UCLASS_I2C, parent, &bus);
+       if (ret) {
+               debug("Cannot find bus for node '%s: ret=%d'\n",
+                     fdt_get_name(blob, parent, NULL), ret);
+               return ret;
+       }
+
+       chip_addr = fdtdec_get_int(blob, node, "reg", -1);
+       if (chip_addr == -1) {
+               debug("Cannot find reg property for node '%s: ret=%d'\n",
+                     fdt_get_name(blob, node, NULL), ret);
+               return ret;
+       }
+       /*
+        * TODO(sjg@chromium.org): Older TPMs will need to use the older method
+        * in iic_tpm_read() so the offset length needs to be 0 here.
+        */
+       ret = i2c_get_chip(bus, chip_addr, 1, &dev->dev);
+       if (ret) {
+               debug("Cannot find device for node '%s: ret=%d'\n",
+                     fdt_get_name(blob, node, NULL), ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+struct tpm_chip *tpm_register_hardware(const struct tpm_vendor_specific *entry)
+{
+       struct tpm_chip *chip;
+
+       /* Driver specific per-device data */
+       chip = &g_chip;
+       memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
+       chip->is_open = 1;
+
+       return chip;
+}
+
+int tis_init(void)
+{
+       if (tpm.inited)
+               return 0;
+
+       if (tpm_decode_config(&tpm))
+               return -1;
+
+       debug("%s: done\n", __func__);
+
+       tpm.inited = 1;
+
+       return 0;
+}
+
+int tis_open(void)
+{
+       int rc;
+
+       if (!tpm.inited)
+               return -1;
+
+       rc = tpm_open_dev(tpm.dev);
+
+       return rc;
+}
+
+int tis_close(void)
+{
+       if (!tpm.inited)
+               return -1;
+
+       tpm_close();
+
+       return 0;
+}
+
+int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
+               uint8_t *recvbuf, size_t *rbuf_len)
+{
+       int len;
+       uint8_t buf[4096];
+
+       if (!tpm.inited)
+               return -1;
+
+       if (sizeof(buf) < sbuf_size)
+               return -1;
+
+       memcpy(buf, sendbuf, sbuf_size);
+
+       len = tpm_transmit(buf, sbuf_size);
+
+       if (len < 10) {
+               *rbuf_len = 0;
+               return -1;
+       }
+
+       memcpy(recvbuf, buf, len);
+       *rbuf_len = len;
+
+       return 0;
 }