tpm: Export the open/close functions

At present these functions are not accessible outside the TPM library, but
in some cases we need to call them. Export them in the header file and add
a define for the SHA1 digest size.

Also adjust tpm_open() to call tpm_close() first so that the TPM is in a
known state before opening (e.g. by a previous phase of U-Boot).

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/tpm-common.h b/include/tpm-common.h
index 449ad4c96e..f8c5569003 100644
--- a/include/tpm-common.h
+++ b/include/tpm-common.h
@@ -182,6 +182,24 @@ int do_##cmd(cmd_tbl_t *cmdtp, int flag,		\
 }
 
 /**
+ * tpm_open() - Request access to locality 0 for the caller
+ *
+ * After all commands have been completed the caller is supposed to
+ * call tpm_close().
+ *
+ * Returns 0 on success, -ve on failure.
+ */
+int tpm_open(struct udevice *dev);
+
+/**
+ * tpm_close() - Close the current session
+ *
+ * Releasing the locked locality. Returns 0 on success, -ve 1 on
+ * failure (in case lock removal did not succeed).
+ */
+int tpm_close(struct udevice *dev);
+
+/**
  * tpm_get_desc() - Get a text description of the TPM
  *
  * @dev:	Device to check