[PATCH] mmc: dt: Add 'broken-cd' DT binding

Thomas Abraham thomas.abraham at linaro.org
Tue Aug 21 22:30:52 EST 2012


On 21 August 2012 17:26, Chris Ball <cjb at laptop.org> wrote:
> Hi,
>
> On Tue, Aug 21 2012, Thomas Abraham wrote:
>> I am trying to have a way to represent a gpio line as card detect line
>> that is not connected to the card-detect pad of the mmc controller but
>> instead used as a gpio interrupt line or polled gpio line.
>>
>> 'broken-cd' would imply that the card-detect pad of the mmc controller
>> is not connected to the card-detect pin at the slot. The 'cd-gpios'
>> property in that case would let the driver code to use the 'cd-gpios'
>> line as the external gpio interrupt or poll it.
>
> How about this?
>
> broken-cd: No CD available, use polling.
>
> cd-gpios: The CD pin on the host is working and brought out to a GPIO.
>
> external-cd-gpios: The CD pin on the host is broken, but there's an
>                    independent external GPIO available.
>
>
> (Each host should only have one of these properties.)

How about a property using 'cd-external' property in place of
'external-cd-gpios'.  'cd-external' would mean that the gpio listed by
'cd-gpios' is a gpio line which is not connected the card-detect pad
of the mmc controller.

This can simplfy the dt parsing code since it is required to look for
only one gpio property, which is 'cd-gpios' which implies lesser error
handling code. 'cd-external' can qualify it further as an external cd
pin.

Either way, I am fine with the binding you have proposed. If you post
a patch for these new bindings, I will base the sdhci-s3c dt patch on
top of that patch.

Thanks,
Thomas.


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