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

On 21 August 2012 17:26, Chris Ball [off-list ref] wrote:

Hi,

On Tue, Aug 21 2012, Thomas Abraham wrote:

quoted

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.