Re: [PATCH v7 6/7] tpm: Add YAML schema for TPM TIS I2C options

From: Rob Herring
Date: Tue May 05 2020 - 12:12:31 EST


On Mon, Apr 27, 2020 at 03:49:30PM +0300, amirmizi6@xxxxxxxxx wrote:
> From: Amir Mizinski <amirmizi6@xxxxxxxxx>
>
> Added a YAML schema to support tpm tis i2c related dt-bindings for the I2c
> PTP based physical layer.
>
> This patch adds the documentation for corresponding device tree bindings of
> I2C based Physical TPM.
> Refer to the 'I2C Interface Definition' section in
> 'TCG PC Client PlatformTPMProfile(PTP) Specification' publication
> for specification.

Again, DT bindings describe h/w devices, not just a protocol. A device
is more than just a protocol interface. There's clocks, power rails,
resets, interrupts, firmware, etc.

Unless there's something special about TPM chips that makes none of this
applicable and no chip will ever have any quirks (or extensions) in
their protocol to work-around, then you need compatible string(s) that
are specific to the TPM chip. You can have tcg,tpm-tis-i2c as a
fallback, but you need specific compatible to handle any quirks.

Rob