Re: [PATCH 1/2] dt-bindings: iommu/rockchip: Make clock properties optional

[Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>]

On 10/04/18 10:26, Heiko Stuebner wrote:
> Rockchip IOMMUs are used without explicit clock handling for 4 years
> now, so we should keep compatibility with old devicetrees if possible.
> Therefore make iommu clocks optional.

Do we need to touch the binding itself? Obviously the driver has to 
treat clocks as optional in existing DTs (and I feel a bit dumb now for 
managing to overlook that in review), but the binding effectively only 
covers future DTs, and I'd assume we want to encourage the clocks to be 
correctly specified there.

Robin.

> Fixes: 8fa9eb39c614 ("dt-bindings: iommu/rockchip: Add clock property")
> Signed-off-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
> ---
>   Documentation/devicetree/bindings/iommu/rockchip,iommu.txt | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt b/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt
> index 6ecefea1c6f9..25bfad987513 100644
> --- a/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt
> +++ b/Documentation/devicetree/bindings/iommu/rockchip,iommu.txt
> @@ -14,13 +14,13 @@ Required properties:
>                       "single-master" device, and needs no additional information
>                       to associate with its master device.  See:
>                       Documentation/devicetree/bindings/iommu/iommu.txt
> +
> +Optional properties:
>   - clocks          : A list of clocks required for the IOMMU to be accessible by
>                       the host CPU.
>   - clock-names     : Should contain the following:
>   	"iface" - Main peripheral bus clock (PCLK/HCL) (required)
>   	"aclk"  - AXI bus clock (required)
> -
> -Optional properties:
>   - rockchip,disable-mmu-reset : Don't use the mmu reset operation.
>   			       Some mmu instances may produce unexpected results
>   			       when the reset operation is used.
>