Re: [PATCH v2 3/6] dt/bindings: Add bindings for Tegra GMI controller

[Mirza Krak]

2016-09-06 12:32 GMT+02:00 Jon Hunter <jonathanh@xxxxxxxxxx>:
>
> On 31/08/16 12:22, Mirza Krak wrote:
>> 2016-08-30 19:06 GMT+02:00 Rob Herring <robh@xxxxxxxxxx>:
>
> ...
>
>>>>                  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?
>

Hi.

I have been on vacation and now I am back and wanted to finalize these
patch series.

So pinging this thread to see I we can agree on a solution.

Rob any comments to my proposal and Jon`s comment?

Best Regards
Mirza Krak