[coreboot] Can the TPM work with only GRUB2 as payload?

[G]

Hello,
I'm currently using coreboot with GRUB2 as a primary ad only payload an 
a ThinkPad X220 with Qubes OS. Everything works fairly smoothly except i 
can't get the TPM to work.

 From dmesg:
[    4.997508] tpm_tis 00:06: 1.2 TPM (device-id 0x0, rev-id 78)
[    5.029507] tpm tpm0: A TPM error (6) occurred attempting to read a 
pcr value
[    5.029514] tpm tpm0: TPM is disabled/deactivated (0x6)


Relevant coreboot build config
CONFIG_TPM_PIRQ=0x0
# CONFIG_MAINBOARD_HAS_I2C_TPM_ATMEL is not set
# CONFIG_MAINBOARD_HAS_I2C_TPM_CR50 is not set
CONFIG_LPC_TPM=y
CONFIG_TPM_TIS_BASE_ADDRESS=0xfed40000
# CONFIG_TPM_INIT_FAILURE_IS_FATAL is not set
# CONFIG_SKIP_TPM_STARTUP_ON_NORMAL_BOOT is not set
# CONFIG_TPM_DEACTIVATE is not set
# CONFIG_MAINBOARD_HAS_SPI_TPM_CR50 is not set
# CONFIG_TPM is not set
# CONFIG_MAINBOARD_HAS_TPM_CR50 is not set
CONFIG_MAINBOARD_HAS_LPC_TPM=y
# CONFIG_MAINBOARD_HAS_TPM2 is not set

I tries setting CONFIG_TPM_DEACTIVATE=n and CONFIG_TPM=y but it looks 
like it has no effect. Also if using 'make menuconfig' the submenu 
relative to the TPM configuration is empty.

Giulio