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

[Shawn Guo]

On Tue, Aug 21, 2012 at 11:03:59PM +0530, Thomas Abraham wrote:
> Ok, I agree with Rob. I was mixing pin muxing here. So if we have
> 'cd-gpios' and 'broken-cd' as generic bindings, would the following be
> valid?
> 
> [A] cd-gpios not present ,  broken-cd not present : This means that
> there is no card detect pin available. Controller drivers are free to
> infer this as "card detection is broken" and use implementation
> specific behavior.
> 
> [B] cd-gpio not present , broken-cd present :  This means that there
> is nothing connected to the card-detect pad of the mmc host
> controller. Controller drivers are free to use implementation specific
> behavior to deal with card detection.
> 
> [C] cd-gpio present, broken-cd not present : This means that 'cd-gpio'
> line connects card-detect pad of the controller to the card-detect pin
> of the mmc slot.
> 
> [D] cd-gpio present, broken-cd present : This means that there is
> nothing connected to the card-detect pad of the mmc host controller.
> Controller drivers are free to use the 'cd-gpio' line in any
> implementation specific way.
> 
The following is what I have on my mind.

broken-cd	cd-gpios	implication
-------------------------------------------
no		no		SDHCI CD
no		yes		GPIO CD
yes		no		NO CD / Broken CD
yes		yes		Invalid

yes: property presents
no: property does not present

-- 
Regards,
Shawn