[PATCH v2 10/11] tpm: Add TPM2 support for write_lock

[Simon Glass]

Implement this API function for TPM2.

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

(no changes since v1)

 include/tpm-v2.h | 12 ++++++++++++
 lib/tpm-v2.c     | 23 +++++++++++++++++++++++
 lib/tpm_api.c    |  2 +-
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 6a400771af1..1ca1e7e2011 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -241,6 +241,7 @@ enum tpm2_command_codes {
 	TPM2_CC_NV_DEFINE_SPACE	= 0x012a,
 	TPM2_CC_PCR_SETAUTHPOL	= 0x012C,
 	TPM2_CC_NV_WRITE	= 0x0137,
+	TPM2_CC_NV_WRITELOCK	= 0x0138,
 	TPM2_CC_DAM_RESET	= 0x0139,
 	TPM2_CC_DAM_PARAMETERS	= 0x013A,
 	TPM2_CC_NV_READ         = 0x014E,
@@ -570,4 +571,15 @@ u32 tpm2_pcr_setauthvalue(struct udevice *dev, const char *pw,
  */
 u32 tpm2_get_random(struct udevice *dev, void *data, u32 count);
 
+/**
+ * Lock data in the TPM
+ *
+ * Once locked the data cannot be written until after a reboot
+ *
+ * @dev		TPM device
+ * @index	Index of data to lock
+ * @return code of the operation
+ */
+u32 tpm2_write_lock(struct udevice *dev, u32 index);
+
 #endif /* __TPM_V2_H */
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 40633b63a94..15e12bc2f41 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -598,3 +598,26 @@ u32 tpm2_get_random(struct udevice *dev, void *data, u32 count)
 
 	return 0;
 }
+
+u32 tpm2_write_lock(struct udevice *dev, u32 index)
+{
+	u8 command_v2[COMMAND_BUFFER_SIZE] = {
+		/* header 10 bytes */
+		tpm_u16(TPM2_ST_SESSIONS),	/* TAG */
+		tpm_u32(10 + 8 + 13), /* Length */
+		tpm_u32(TPM2_CC_NV_WRITELOCK), /* Command code */
+
+		/* handles 8 bytes */
+		tpm_u32(TPM2_RH_PLATFORM),	/* Primary platform seed */
+		tpm_u32(HR_NV_INDEX + index),	/* Password authorisation */
+
+		/* session header 9 bytes */
+		tpm_u32(9),			/* Header size */
+		tpm_u32(TPM2_RS_PW),		/* Password authorisation */
+		tpm_u16(0),			/* nonce_size */
+		0,				/* session_attrs */
+		tpm_u16(0),			/* auth_size */
+	};
+
+	return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+}
diff --git a/lib/tpm_api.c b/lib/tpm_api.c
index 687fc8bc7ee..4c662640a92 100644
--- a/lib/tpm_api.c
+++ b/lib/tpm_api.c
@@ -144,7 +144,7 @@ u32 tpm_write_lock(struct udevice *dev, u32 index)
 	if (is_tpm1(dev))
 		return -ENOSYS;
 	else if (is_tpm2(dev))
-		return -ENOSYS;
+		return tpm2_write_lock(dev, index);
 	else
 		return -ENOSYS;
 }
-- 
2.30.0.296.g2bfb1c46d8-goog