On 04/28/2014 05:18 AM, Thierry Reding wrote: > On Mon, Apr 28, 2014 at 12:56:03PM +0200, Arnd Bergmann wrote: ... >> A lot of drivers probably only support one >> master, so they can just set #iommu-cells=<0>, others might require >> IDs that do not fit into one cell. > > You mean "#iommu-cells = <1>" for devices that only require one master? > There still has to be one cell to specify which master. Unless perhaps > if they can be arbitrarily assigned. I guess even if there's a fixed > mapping that applies to one SoC generation, it might be good to still > employ a specifier and have the mapping in DT for flexibility. #iommu-cells doesn't include the phandle, so if you want the client references to be: property = <&iommu>; then that's #iommu-cells=<0>, whereas: property = <&iommu N>; is #iommu-cells=<1>. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
