On Tue, Dec 17, 2013 at 6:05 AM, Jonas Jensen <jonas.jensen@xxxxxxxxx> wrote:
> On 15 December 2013 05:27, Peter Crosthwaite
> <peter.crosthwaite@xxxxxxxxxx> wrote:
>>> + sdhci: sdhci@98e00000 {
>>> + compatible = "moxa,moxart-sdhci";
>>> + reg = <0x98e00000 0x5C>;
>>> + interrupts = <5 0>;
>>> + clocks = <&clk_apb>;
>>> + dmas = <&dma 5>,
>>> + <&dma 5>;
>>> + dma-names = "tx", "rx";
>>> + };
>>
>> Is your SDHCI really implemented on the board level? The fact that its
>> reg property is within the same as the SoC range (for your dtsi)
>> suggests the SDHCI is part of the SoC and should perhaps be in the
>> dtsi?
>
>>> + mac1: mac@92000000 {
>>> + compatible = "moxa,moxart-mac";
>>> + reg = <0x92000000 0x90>;
>>> + interrupts = <27 0>;
>>> + phy-handle = <ðphy1>;
>>> + phy-mode = "mii";
>>> + };
>>
>> Same for MACs.
>
>>> +
>>> + uart0: uart@98200000 {
>>> + compatible = "ns16550a";
>>> + reg = <0x98200000 0x20>;
>>> + interrupts = <31 8>;
>>> + reg-shift = <2>;
>>> + reg-io-width = <4>;
>>> + clock-frequency = <14745600>;
>>> + status = "okay";
>>> + };
>>> +
>>
>> And UARTs.
>>
>> Let me know if i'm misunderstanding dts/dtsi split but looking at some
>> of the other SoCs this seems inconsistent to me.
>
>
> It is likely to be true, that technically these are all part of the
> SoC. By examining the hardware, there are no external chips (on either
> base or main board) that looks capable of handling such functions:
>
> https://plus.google.com/photos/103371465418643926605/albums/5820634595801767953
>
> I made the split with some consideration to other MOXA ART machines,
> that they can be added as a separate file including the same dtsi:
>
> MOXA ART hardware examples:
>
> UC-7112/UC-7110: "SD slot (UC-7112, and UC-7112 Plus only)":
> http://www.moxa.com/product/UC-7112_UC-7110.htm
>
> IA241: "64 MB RAM":
> http://www.moxa.com/product/IA241_IA240.htm
>
> UC-7101-LX: "One 10/100 Mbps Ethernet port":
> http://www.moxa.com/product/UC-7101-LX.htm
>
>
> UC-7112-LX has 32 MB RAM and two ethernet ports. This is why I think
> MAC is good as is, RAM should move out from SoC?
>
> I don't know if they all have a debug UART (I only have access to
> UC-7112-LX), and it's not obvious in specifications. UART can possibly
> be moved into SoC as you say.
>
I think its going to all be in the SoC. Having it board level would
mean you have a system bus as copper which is not very SoC like (at
least for UART anyway).
> In cases where SD slot is missing but the register remains in the SoC,
> how is that normally handled?
>
Soren Brinkmann's recent addition of ethernet to the Zynq SoC
illustrates the concept for a MAC. The two MACs are added to the
shared dtsi but disabled. The board level dts then enables it for the
one which is board populated:
https://lkml.org/lkml/2013/12/11/434
I think its generally applicable to your SD MAC and UART cases. The
tegra20 dtsi illustrates the status = "disabled" concept specifically
for SDHCI.
Regards,
Peter
>
> Regards,
> Jonas
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