Re: [PATCH 2/4] ARM: dts: da850: Add an aemif node

From: Sekhar Nori
Date: Wed Aug 10 2016 - 16:10:09 EST


On Wednesday 10 August 2016 01:37 PM, Karl Beldan wrote:
> On Wed, Aug 10, 2016 at 01:32:03PM +0530, Sekhar Nori wrote:
>> On Wednesday 10 August 2016 01:18 PM, Sekhar Nori wrote:
>>> On Tuesday 09 August 2016 10:45 PM, Karl Beldan wrote:
>>>> Currently the davinci da8xx boards use the mach-davinci aemif code.
>>>> Instantiating an aemif node into the DT allows to use the ti-aemif
>>>> memory driver and is another step to better DT support.
>>>> Also it will allow to properly pass the emif timings via DT.
>>>>
>>>> Signed-off-by: Karl Beldan <kbeldan@xxxxxxxxxxxx>
>>>> ---
>>>> arch/arm/boot/dts/da850.dtsi | 10 ++++++++++
>>>> 1 file changed, 10 insertions(+)
>>>>
>>>> diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
>>>> index bc10e7e..f62928c 100644
>>>> --- a/arch/arm/boot/dts/da850.dtsi
>>>> +++ b/arch/arm/boot/dts/da850.dtsi
>>>> @@ -411,6 +411,16 @@
>>>> dma-names = "tx", "rx";
>>>> };
>>>> };
>>>> + aemif: aemif@68000000 {
>>>> + compatible = "ti,da850-aemif";
>>>> + #address-cells = <2>;
>>>> + #size-cells = <1>;
>>>> +
>>>> + reg = <0x68000000 0x00008000>;
>>>> + ranges = <0 0 0x60000000 0x08000000
>>>> + 1 0 0x68000000 0x00008000>;
>>>> + status = "disabled";
>>>> + };
>>>> nand_cs3@62000000 {
>>>> compatible = "ti,davinci-nand";
>>>> reg = <0x62000000 0x807ff
>>>
>>> The nand node should be part of aemif node like it is done for keystone
>>> boards.
>>
>> Actually, can you move the nand node out of da850.dtsi completely. Its
>> much better to keep da850.dtsi restricted to soc-internal devices and
>> keep the board level devices like NAND flash in <board>.dts file.
>>
>> Similarly, can you move the NAND pinmux definitions too to the
>> da850-evm.dts file?
>>
>> There is advantage in keeping common pinmux definitions in da850.dtsi so
>> each board doe not have to repeat them. But AEMIF is an exception as its
>> usage can really be varied (NAND, NOR, SRAM, other). Plus, different
>> boards are likely to use different chip selects so coming up with some
>> pinmux definitions which will be reused widely is really unlikely.
>>
> This is exactly what I just did for the LCDK.
> If everybody is happy with it I will do the same for the evm as I put it
> in the cover letter.

Yes please. We dont want duplication of data between da850.dtsi and
da850-lcdk.dts files.

Thanks,
Sekhar