[RFC][PATCH 2/9] tpm_tis_core: access single TIS registers before doing complex transfers

[Alexander Steffen <Alexander.Steffen@infineon.com>]

There are several TIS registers that contain information on how exactly the
TPM implements the TIS protocol. Complex commands that are used by the
probe functions should only be sent to the TPM after all other registers
have been read and the driver is properly configured to handle those
transactions.

Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
---
 drivers/char/tpm/tpm_tis_core.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index ca6b2b5..d367016 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -781,10 +781,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	intmask &= ~TPM_GLOBAL_INT_ENABLE;
 	tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
 
-	rc = tpm2_probe(chip);
-	if (rc)
-		goto out_err;
-
 	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
 	if (rc < 0)
 		goto out_err;
@@ -795,16 +791,6 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	if (rc < 0)
 		goto out_err;
 
-	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
-		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
-		 vendor >> 16, rid);
-
-	probe = probe_itpm(chip);
-	if (probe < 0) {
-		rc = -ENODEV;
-		goto out_err;
-	}
-
 	/* Figure out the capabilities */
 	rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
 	if (rc < 0)
@@ -831,6 +817,20 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
 		dev_dbg(dev, "\tData Avail Int Support\n");
 
+	rc = tpm2_probe(chip);
+	if (rc)
+		goto out_err;
+
+	dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
+		 (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
+		 vendor >> 16, rid);
+
+	probe = probe_itpm(chip);
+	if (probe < 0) {
+		rc = -ENODEV;
+		goto out_err;
+	}
+
 	/* INTERRUPT Setup */
 	init_waitqueue_head(&priv->read_queue);
 	init_waitqueue_head(&priv->int_queue);
-- 
2.7.4