Re: [PATCHv3 07/14] HSI: Add common DT binding for HSI client devices

[Rob Herring]

On Fri, Mar 28, 2014 at 7:31 PM, Sebastian Reichel <sre@xxxxxxxxxx> wrote:
> Implement and document generic DT bindings for HSI clients.
>
> Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>

Seems pretty reasonable although I know little about HSI.

> ---
>  .../devicetree/bindings/hsi/client-devices.txt     |  44 +++++
>  drivers/hsi/hsi.c                                  | 197 ++++++++++++++++++++-
>  include/linux/hsi/hsi.h                            |   2 +
>  3 files changed, 241 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/hsi/client-devices.txt
>
> diff --git a/Documentation/devicetree/bindings/hsi/client-devices.txt b/Documentation/devicetree/bindings/hsi/client-devices.txt
> new file mode 100644
> index 0000000..7504cb1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hsi/client-devices.txt
> @@ -0,0 +1,44 @@
> +Each HSI port is supposed to have one child node, which
> +symbols the remote device connected to the HSI port. The
> +following properties are standardized for HSI clients:
> +
> +Required HSI configuration properties:
> +
> +- reg:                 A list of channel ids
> +
> +- hsi-rx-mode:         Receiver Bit transmission mode ("stream" or "frame")
> +- hsi-tx-mode:         Transmitter Bit transmission mode ("stream" or "frame")
> +- hsi-mode:            May be used instead hsi-rx-mode and hsi-tx-mode if
> +                       the transmission mode is the same for receiver and
> +                       transmitter
> +- hsi-speed-kbps:      Max bit transmission speed in kbit/s
> +- hsi-flow:            RX flow type ("synchronized" or "pipeline")
> +- hsi-arb-mode:                Arbitration mode for TX frame ("round-robin", "priority")
> +
> +Optional HSI configuration properties:
> +
> +- reg-names:           A list with one name per channel specified in the
> +                       reg property
> +
> +
> +Device Tree node example for an HSI client:
> +
> +hsi-controller {
> +       hsi-port {
> +               modem: hsi-client {
> +                       compatible = "nokia,n900-modem";

Is there only 1 version of HSI? If not, then perhaps you need to know
what version a client is.

> +
> +                       reg = <0>, <1>, <2>, <3>;

Where do these numbers get defined? Are they always 0-N?

I don't see much advantage to using reg. Perhaps something like
hsi-channel-ids would be better.

Rob
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