Re: [PATCH 1/2] tpm: devicetree: document properties for cr50

Guenter Roeck
2016-07-15T04:05:56Z

On Thu, Jul 14, 2016 at 7:20 PM, Andrey Pronin <apronin@chromium.org> wrote:
> Add TPM2.0-compatible interface to Cr50. Document its properties
> in devicetree.
>
> Signed-off-by: Andrey Pronin <apronin@chromium.org>
> ---
> .../devicetree/bindings/security/tpm/cr50_spi.txt | 30 ++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/security/tpm/cr50_spi.txt
>
> diff --git a/Documentation/devicetree/bindings/security/tpm/cr50_spi.txt b/Documentation/devicetree/bindings/security/tpm/cr50_spi.txt
> new file mode 100644
> index 0000000..1b05e51
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/security/tpm/cr50_spi.txt
> @@ -0,0 +1,30 @@
> +* Cr50 Chip on SPI.
> +
> +TCG PTP FIFO Compliant Interface to Cr50 on SPI bus.
> +
> +Required properties:
> +- compatible: Should be "google,cr50_spi".

google,cr50, maybe ? The "_spi" seems redundant.

Also, I agree with comments from others - the term cr50 really needs
an explanation (Google thinks that it is a motor bike, a scanner, or a
coffee roaster).

Thanks,
Guenter

> +- spi-max-frequency: Maximum SPI frequency.
> +
> +Optional properties:
> +- access-delay-msec: Required delay between subsequent transactions on SPI.
> +- sleep-delay-msec: Time after the last SPI activity, after which the chip
> + may go to sleep.
> +- wake-start-delay-msec: Time after initiating wake up before the chip is
> + ready to accept commands over SPI.
> +
> +Example:
> +
> +&spi0 {
> + status = "okay";
> +
> + cr50@0 {
> + compatible = "google,cr50_spi";
> + reg = <0>;
> + spi-max-frequency = <800000>;
> +
> + access-delay-msec = <2>;
> + sleep-delay-msec = <1000>;
> + wake-start-delay-msec = <60>;
> + };
> +};
> --
> 2.6.6
>