Hello Cedric,
Joel helped me to configure the device and we are able to configure tpm device
on ast2600-evb.
I will include this example in the documentation.
# uname -a
Linux ast2600-evb 6.1.15 #1 SMP Thu Mar 23 20:48:29 CDT 2023 armv7l GNU/Linux
# cat /etc/os-release
NAME=Buildroot
VERSION=2023.02-dirty
ID=buildroot
VERSION_ID=2023.02
PRETTY_NAME="Buildroot 2023.02"
# echo tpm_tis_i2c 0x2e > /sys/bus/i2c/devices/i2c-12/new_device
[ 59.681684] tpm_tis_i2c 12-002e: 2.0 TPM (device-id 0x1, rev-id 1)
[ 59.703190] tpm tpm0: A TPM error (256) occurred attempting the self test
[ 59.705215] tpm tpm0: starting up the TPM manually
[ 59.892917] i2c i2c-12: new_device: Instantiated device tpm_tis_i2c at 0x2e
# cd /sys/class/tpm/tpm0
# ls
dev pcr-sha256 power uevent
device pcr-sha384 subsystem
pcr-sha1 pcr-sha512 tpm_version_major