Change in coreboot[master]: mb/lenovo/x60: Enable TPM

[Masanori Ogino (Code Review)]

Masanori Ogino has uploaded a new patch set (#11) to the change originally created by Denis Carikli. ( https://review.coreboot.org/c/coreboot/+/13410 )

Change subject: mb/lenovo/x60: Enable TPM
......................................................................

mb/lenovo/x60: Enable TPM

Enable the onboard TPM device in the devicetree, and select Kconfig
options to add the appropriate ASL code.

This is adapted from commit 3d02b9c7.
(mainboard/lenovo/{t430s,t420s,t520,t530,x220}: Add TPM 1.2 mainboard
support)

Without this, coreboot doesn't touch the device and generates no ACPI
entry for it. Thus, in GNU/Linux, it is not detected automatically.

You can, however, force the Linux kernel to scan buses by running the
following commands:

# modprobe -r tpm_tis
    # modprobe tpm_tis force=1

Running the commands above outputs some messages to dmesg, although the
actual messages vary between kernel versions. With Linux 4.9.235:

tpm_tis tpm_tis: 1.2 TPM (device-id 0x3202, rev-id 5)
    tpm tpm0: Issuing TPM_STARTUP
    tpm tpm0: [Hardware Error]: Adjusting reported timeouts: A 10000->10000us B 10000->10000us C 0->750000us D 0->750000us
    tpm tpm0: [Hardware Error]: Adjusting reported timeouts: A 10000->10000us B 10000->10000us C 0->750000us D 0->750000us
    tpm tpm0: TPM is disabled/deactivated (0x6)

Then /dev/tpm0 is created. The content of /sys/class/tpm/tpm0/caps is:

Manufacturer: 0x41544d4c
    TCG version: 1.2
    Firmware version: 11.5

With Linux 5.4.64:

tpm_tis tpm_tis: 1.2 TPM (device-id 0xFFFF, rev-id 255)
    tpm tpm0: tpm_try_transmit: send(): error -5
    tpm tpm0: A TPM error (-5) occurred attempting to determine the timeouts
    tpm_tis tpm_tis: Could not get TPM timeouts and durations

In this case, tpm0 is not created.

Now, coreboot tries to initialize the device but fails to do so. From
the console log:

lpc_tpm: Read reg 0xf00 returns 0xffffffff
    tis_probe: No TPM device found
    TPM: Can't initialize.

While coreboot provides an ACPI entry anyway, for some reasons, Linux
still does not scan the device automatically.

See also previous discussions on LKML [1].

[1]: https://lore.kernel.org/lkml/?q=Regression+between+Linux+3.16+and+4.8%2F4.9+...

Change-Id: I6e65b37507c111af1c0c56822327d5497f58f085
Signed-off-by: Denis 'GNUtoo' Carikli 
Signed-off-by: Paul Menzel 
Signed-off-by: Masanori Ogino 
---
M src/mainboard/lenovo/x60/Kconfig
M src/mainboard/lenovo/x60/devicetree.cb
2 files changed, 5 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/10/13410/11