Introduce generic TPM support in u-boot

TPM (Trusted Platform Module) is an integrated circuit and
software platform that provides computer manufacturers with the
core components of a subsystem used to assure authenticity,
integrity and confidentiality.

This driver supports version 1.2 of the TCG (Trusted Computing
Group) specifications.

The TCG specification defines several so called localities in a
TPM chip, to be controlled by different software layers. When
used on a typical x86 platform during the firmware phase, only
locality 0 can be accessed by the CPU, so this driver even while
supporting the locality concept presumes that only locality zero
is used.

This implementation is loosely based on the article "Writing a
TPM Device Driver" published on http://ptgmedia.pearsoncmg.com

Compiling this driver with DEBUG defined will generate trace of
all accesses to TMP registers.

This driver has been tested and is being used in three different
functional ChromeOS machines (Pinetrail and Sandy Bridge Intel
chipsets) all using the same Infineon SLB 9635 TT 1.2 device.

A u-boot cli command allowing access to the TPM was also
implemented and is being submitted as a second patch.

Change-Id: I22a33c3e5b2e20eec9557a7621bd463b30389d73
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
CC: Wolfgang Denk <wd@denx.de>

1 files changed, 71 insertions, 0 deletions

diff --git a/include/tpm.h b/include/tpm.h
new file mode 100644
index 0000000..6b21e9c
--- /dev/null
+++ b/include/tpm.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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
+ */
+
+#ifndef _INCLUDE_TPM_H_
+#define _INCLUDE_TPM_H_
+
+#include <common.h>
+
+/*
+ * tis_init()
+ *
+ * Initialize the TPM device. Returns 0 on success or -1 on
+ * failure (in case device probing did not succeed).
+ */
+int tis_init(void);
+
+/*
+ * tis_open()
+ *
+ * Requests access to locality 0 for the caller. After all commands have been
+ * completed the caller is supposed to call tis_close().
+ *
+ * Returns 0 on success, -1 on failure.
+ */
+int tis_open(void);
+
+/*
+ * tis_close()
+ *
+ * terminate the currect session with the TPM by releasing the locked
+ * locality. Returns 0 on success of -1 on failure (in case lock
+ * removal did not succeed).
+ */
+int tis_close(void);
+
+/*
+ * tis_sendrecv()
+ *
+ * Send the requested data to the TPM and then try to get its response
+ *
+ * @sendbuf - buffer of the data to send
+ * @send_size size of the data to send
+ * @recvbuf - memory to save the response to
+ * @recv_len - pointer to the size of the response buffer
+ *
+ * Returns 0 on success (and places the number of response bytes at recv_len)
+ * or -1 on failure.
+ */
+int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
+			size_t *recv_len);
+
+#endif /* _INCLUDE_TPM_H_ */