Re: [RFC PATCH 01/12] dt-bindings: soc: qcom: add IPA bindings

[Arnd Bergmann]

On Wed, Nov 7, 2018 at 1:33 AM Alex Elder <elder@xxxxxxxxxx> wrote:
>
> Add the binding definitions for the "qcom,ipa" and "qcom,rmnet-ipa"
> device tree nodes.
>
> Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/soc/qcom/qcom,ipa.txt | 136 ++++++++++++++++++
>  .../bindings/soc/qcom/qcom,rmnet-ipa.txt      |  15 ++
>  2 files changed, 151 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt
>  create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,rmnet-ipa.txt

I think this should go into bindings/net instead of bindings/soc, since it's
mostly about networking rather than a specific detail of managing the SoC
itself.

> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt
> new file mode 100644
> index 000000000000..d4d3d37df029
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,ipa.txt
> @@ -0,0 +1,136 @@
> +Qualcomm IPA (IP Accelerator) Driver
> +
> +This binding describes the Qualcomm IPA.  The IPA is capable of offloading
> +certain network processing tasks (e.g. filtering, routing, and NAT) from
> +the main processor.  The IPA currently serves only as a network interface,
> +providing access to an LTE network available via a modem.

That doesn't belong into the binding. Say what the hardware can do here,
not what a specific implementation of the driver does at this moment.
The binding should be written in an OS independent way after all.

> +- interrupts-extended:
> +       Specifies the IRQs used by the IPA.  Four cells are required,
> +       specifying: the IPA IRQ; the GSI IRQ; the clock query interrupt
> +       from the modem; and the "ready for stage 2 initialization"
> +       interrupt from the modem.  The first two are hardware IRQs; the
> +       third and fourth are SMP2P input interrupts.

You mean 'four interrupts', not 'four cells' -- each interrupt specifier
already consists of at least two cells (one for the phandle to the
irqchip, plus one or more cells to describe that interrupt).

> +- interconnects:
> +       Specifies the interconnects used by the IPA.  Three cells are
> +       required, specifying:  the path from the IPA to memory; from
> +       IPA to internal (SoC resident) memory; and between the AP
> +       subsystem and IPA for register access.

Same here and in the rest.

      Arnd