Messages in this thread | | | Subject | Re: [PATCH v2 3/6] dt/bindings: Add bindings for Tegra GMI controller | From | Jon Hunter <> | Date | Tue, 6 Sep 2016 11:32:14 +0100 |
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On 31/08/16 12:22, Mirza Krak wrote: > 2016-08-30 19:06 GMT+02:00 Rob Herring <robh@kernel.org>:
...
>>> nvidia,snor-cs = <4>; >> >> NAK, no custom CS properties.
Ok, so ...
> gmi@70090000 { > compatible = "nvidia,tegra20-gmi"; > reg = <0x70009000 0x1000>; > #address-cells = <2>; > #size-cells = <1>; > clocks = <&tegra_car TEGRA20_CLK_NOR>; > clock-names = "gmi"; > resets = <&tegra_car 42>; > reset-names = "gmi"; > ranges = <4 0 0xd0000000 0xfffffff>; > > status = "okay"; > > bus@4,0 { > compatible = "simple-bus"; > #address-cells = <1>; > #size-cells = <1>; > ranges = <0 4 0 0x40000>; > > nvidia,snor-mux-mode; > nvidia,snor-adv-inv; > > can@0 { > reg = <0 0x100>; > ... > }; > > can@40000 { > reg = <0x40000 0x100>; > ... > }; > }; > }; > > Have I understood you correct? > > Also wanted to verify the example case where you only have on device > connected to one CS#, from what I see in other implementations it > seems OK to put the CS# in the reg property in that case. Is this > correct? > > Example with one SJA1000 CAN controller connected to the GMI bus > on CS4: > > gmi@70090000 { > compatible = "nvidia,tegra20-gmi"; > reg = <0x70009000 0x1000>; > #address-cells = <2>; > #size-cells = <1>; > clocks = <&tegra_car TEGRA20_CLK_NOR>; > clock-names = "gmi"; > resets = <&tegra_car 42>; > reset-names = "gmi"; > ranges = <4 0 0xd0000000 0xfffffff>; > > status = "okay"; > > can@4,0 { > reg = <4 0 0x100>; > nvidia,snor-mux-mode; > nvidia,snor-adv-inv; > ... > }; > }; > > Jon, to be able to handle both cases in the driver we would first > attempt to decode the CS# from the ranges property, and fallback to > reg property if no ranges are defined. Does that sound reasonable?
Given the above examples that may be supported, is there a better/simpler way to extract the CS# than what Mirza is proposing? For example, from the node-name unit-address?
Cheers Jon
-- nvpublic
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