[MinnowBoard] Using a TPM on the MinnowBoard connected with I2C

[Sebastien Duc]

Hi all,

Please bare with me if something I am saying is wrong, I don't have much
experience with TPMs or I2C.

I recently acquired a minnowboard max to attempt some experimentation with
TPMs.
I have also bought a separate TPM from Atmel (it's the TPM i2c development
Kit AT97SC3205T).

So far I have connected the TPM board to the Minnowboard through i2c. I
made sure to connect pin 2 (the ground) and 4 (+3V3) of the Minnowboard to
the corresponding GND and VCC of my TPM board. I also connected pin 13
(SCL) and 15 (SDA) to the corresponding SCL and SDA of the TPM board.

I have installed Debian on the board and made sure to build a kernel that
has tpm_i2c_atmel as a module. The version of my kernel is 4.3.0.

Now I am trying to load the kernel module as so:
# insmod tpm_i2c_atmel.ko

The insmod is being executed without any errors and I cannot see anything
in dmesg.
However when looking at my devices, I don't see any tpm0 in /dev.

I can also see tpm_i2c atmel.ko in the list of loaded modules when looking
at
# lsmod

Therefore when I am trying to start tcsd, it fails:
# tcsd -f
# TCSD TDDL ERROR: Could not find a device to open!

I also made sure in the BIOS  to enable Discrete TPM.

So my guess is that either my TPM is not properly connect but I don't
really know how to test this. Or I am missing some software configuration
somewhere.

I was hoping that someone could help me with this. How can I know if I did
the connectivity properly? What configuration do I need to do before being
able to talk to the TPM, especially to use the i2c pins on the Minnowboard?

Let me know if you need more information.

Thanks,
Sebastien
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