[PATCH 1/1] tpm: clear state post probing

[Heinrich Schuchardt <heinrich.schuchardt@canonical.com>]

Before we can start measuring the TPM must be cleared. Do this in the
post_probe() method of the uclass.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
 drivers/tpm/tpm-uclass.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/tpm/tpm-uclass.c b/drivers/tpm/tpm-uclass.c
index f67fe1019b..9180551d6f 100644
--- a/drivers/tpm/tpm-uclass.c
+++ b/drivers/tpm/tpm-uclass.c
@@ -11,6 +11,7 @@
 #include <log.h>
 #include <linux/delay.h>
 #include <linux/unaligned/be_byteshift.h>
+#include <tpm_api.h>
 #include <tpm-v1.h>
 #include <tpm-v2.h>
 #include "tpm_internal.h"
@@ -136,6 +137,26 @@ int tpm_xfer(struct udevice *dev, const uint8_t *sendbuf, size_t send_size,
 	return 0;
 }
 
+static int dm_tpm_post_probe(struct udevice *dev)
+{
+	struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
+
+	/*
+	 * Clearing the TPM state is only possible once after a hard reset.
+	 * As we do not know if the TPM has been cleared by a prior boot stage
+	 * ignore the return value here.
+	 */
+	switch (priv->version) {
+	case TPM_V1:
+		tpm_startup(dev, TPM_ST_CLEAR);
+		break;
+	case TPM_V2:
+		tpm2_startup(dev, TPM2_SU_CLEAR);
+		break;
+	}
+	return 0;
+}
+
 UCLASS_DRIVER(tpm) = {
 	.id		= UCLASS_TPM,
 	.name		= "tpm",
@@ -143,5 +164,6 @@ UCLASS_DRIVER(tpm) = {
 #if CONFIG_IS_ENABLED(OF_REAL)
 	.post_bind	= dm_scan_fdt_dev,
 #endif
+	.post_probe	= dm_tpm_post_probe,
 	.per_device_auto	= sizeof(struct tpm_chip_priv),
 };
-- 
2.32.0