[coreboot-gerrit] [S] Change in coreboot[main]: drivers/pc80/tpm: Disable device if TPM not present

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/80455?usp=email )

Change subject: drivers/pc80/tpm: Disable device if TPM not present
......................................................................

drivers/pc80/tpm: Disable device if TPM not present

If the TPM is not detected in the system it may	mean it	is inactive
due to enabled ME with active PTT. In such case, the chipset will route
the TPM	traffic to PTT CRB TPM on Intel systems.

If TPM is not probed, disable the PC80 TPM device driver, so that
coreboot will not generate improper SSDT ACPI table.

Change-Id: I05972ad74a36abaafa2f17a16f09710550a3a3f3
Signed-off-by: Michał Żygowski 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80455
Tested-by: build bot (Jenkins) 
Reviewed-by: Sergii Dmytruk 
---
M src/drivers/pc80/tpm/tis.c
1 file changed, 9 insertions(+), 4 deletions(-)

Approvals:
  Sergii Dmytruk: Looks good to me, approved
  build bot (Jenkins): Verified

diff --git a/src/drivers/pc80/tpm/tis.c b/src/drivers/pc80/tpm/tis.c
index f922714..d811c52 100644
--- a/src/drivers/pc80/tpm/tis.c
+++ b/src/drivers/pc80/tpm/tis.c
@@ -905,11 +905,16 @@

static void enable_dev(struct device *dev)
 {
-	if (CONFIG(TPM))
-		pnp_enable_devices(dev, &lpc_tpm_ops,
-			ARRAY_SIZE(pnp_dev_info), pnp_dev_info);
-	else
+	if (CONFIG(TPM)) {
+		if (pc80_tis_probe(NULL) == NULL) {
+			dev->enabled = 0;
+			return;
+		}
+
+		pnp_enable_devices(dev, &lpc_tpm_ops, ARRAY_SIZE(pnp_dev_info), pnp_dev_info);
+	} else {
    	pnp_enable_devices(dev, &noop_tpm_ops, ARRAY_SIZE(pnp_dev_info), pnp_dev_info);
+	}
 }

struct chip_operations drivers_pc80_tpm_ops = {