Re: [PATCH] arm: dts: omap5-uevm: Add status parameter for i2c/spi/uart.

[Sekhar Nori <nsekhar@ti.com>]

On Tuesday 24 September 2013 11:18 AM, Sourav Poddar wrote:
> On Tuesday 24 September 2013 11:14 AM, Sekhar Nori wrote:
>> On Tuesday 24 September 2013 11:09 AM, Sourav Poddar wrote:
>>> omap5 has all devices enable by default.
>>> Disable thosw not required in omap5 uevm board.
>> s/thosw/those
>>
>>> Fix the following:
>>> Added status parameter
>>> Simulataneously, fix some tab formatting.
>> s/Simulataneously/Simultaneously
>>
>>> Signed-off-by: Sourav Poddar<sourav.poddar@ti.com>
>>> ---
>>>   arch/arm/boot/dts/omap5-uevm.dts |   38
>>> +++++++++++++++++++++++++++++++-------
>>>   1 files changed, 31 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/arch/arm/boot/dts/omap5-uevm.dts
>>> b/arch/arm/boot/dts/omap5-uevm.dts
>>> index 65d7b60..78cf0f2 100644
>>> --- a/arch/arm/boot/dts/omap5-uevm.dts
>>> +++ b/arch/arm/boot/dts/omap5-uevm.dts
>>> @@ -450,6 +450,18 @@
>>>       };
>>>   };
>>>
>>> +&i2c2 {
>>> +    status = "disabled";
>>> +};
>>> +
>>> +&i2c3 {
>>> +    status = "disabled";
>>> +};
>>> +
>>> +&i2c4 {
>>> +    status = "disabled";
>>> +};
>> The right thing to do would be to mark these as disabled in omap5.dtsi
>> so boards can enable only what they need instead of disable what they
>> don't need (which is potentially a very long list)
> Yes, initially I thought so. But saw these varies from soc to soc.
> On DRA, it is done the way you suggested. For omap5, I saw mmc
> getting disabled in board dts.
> 
> I can change these though. Then, other modules like keypad/mmc should
> also be disable in
> dtsi file to have some uniformity. ?

Yes, that would be nice. This is usually the norm. One exception that is
made is that internal modules like RTC, cryptos can be left enabled in
the <soc>.dtsi so each board doesn't have to enable it. Just make sure
that the module is such that it can really function on *all* boards.
Typically that would mean IOs are not present or optional without loss
of complete functionality.

Thanks,
Sekhar