Re: [PATCH v2 1/3] ftpm: dt-binding: add dts documentation for fTPM driver

[Rob Herring]

On Tue, Apr 9, 2019 at 1:50 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
>
> The parameters are similar to the ones used by IBM's vTPM and the
> various I2C tpm drivers.

Bindings describe h/w (or firmware interfaces in this case), not drivers.

>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
>  .../bindings/security/tpm/tpm_ftpm_tee.txt          | 13 +++++++++++++
>  .../devicetree/bindings/vendor-prefixes.txt         |  1 +
>  2 files changed, 14 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt
>
> diff --git a/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt b/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt
> new file mode 100644
> index 000000000000..20fca67a56c4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/security/tpm/tpm_ftpm_tee.txt
> @@ -0,0 +1,13 @@
> +Required properties:
> +- compatible: should be "microsoft,ftpm"
> +- linux,sml-base: 64-bit base address of the reserved memory allocated
> +                 for the firmware event log
> +- linux,sml-size: size of the memory allocated for the firmware event log

Firmware is defining linux specific properties? What if I want to run
BSD? We should use 'reg' here instead.

What memory is used here? This should be under /reserved-memory if it
is part of "main" memory.

Really, I'd prefer to not see this in DT at all. Make the firmware
discoverable. Why repeat the mistakes of non-discoverable h/w in s/w
interfaces? OP-Tee at least has defined a mechanism to enumerate TEE
functions IIRC.

Rob