Re: [PATCH V3 01/10] Documentation: DT: qcom_hidma: update binding for MSI

From: Mark Rutland
Date: Fri Sep 23 2016 - 14:03:10 EST


On Thu, Sep 15, 2016 at 01:22:37PM -0400, Sinan Kaya wrote:
> Adding a new binding for qcom,hidma-1.1 to distinguish HW supporting
> MSI interrupts from the older revision.
>
> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt b/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
> index fd5618b..47bfb5a 100644
> --- a/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
> +++ b/Documentation/devicetree/bindings/dma/qcom_hidma_mgmt.txt
> @@ -47,12 +47,23 @@ When the OS is not in control of the management interface (i.e. it's a guest),
> the channel nodes appear on their own, not under a management node.
>
> Required properties:
> -- compatible: must contain "qcom,hidma-1.0"
> +- compatible: must contain "qcom,hidma-1.0" for initial HW or "qcom,hidma-1.1"
> +for MSI capable HW.
> - reg: Addresses for the transfer and event channel
> - interrupts: Should contain the event interrupt
> - desc-count: Number of asynchronous requests this channel can handle
> - iommus: required a iommu node
>
> +Optional properties for MSI:
> +- msi-parent: pointer to the MSI controller object with the DeviceID in use.

The format of msi-cells depends on the particular msi-controller, so no
need to mention DeviceID here.

Please refer to
Documentation/devicetree/bindings/interrupt-controller/msi.txt

> +Example:
> + msi_parent: <&msi0 0x80024>

This doesn't match (s/_/-/).

> +msi0 is the MSI controller in the system. Bits 0-5 is the channel ID. 4
> +is the channel ID. Bits 5-8 is the instance number. This is for the HIDMA
> +instance 1.

I don't think you need any of this text, so long as you refer to the
generic MSI binding document, as above.

Thanks,
Mark.