On Tue, 2014-07-08 at 16:43 -0700, Bjorn Andersson wrote:

On Tue, Jul 8, 2014 at 4:20 PM, Stephen Boyd [off-list ref] wrote:

quoted

On 07/07/14 18:26, Bjorn Andersson wrote:

<snip>

[...]

quoted

Sad, the header file came back. I guess there isn't a way to put the
pinctrl driver inside the core mfd driver? Then we wouldn't need to
expose an "irq read line" function.

I continued my search and this needs to be accessed by gpio, mpp, adc,
charger, bms and usb(?). So we have to expose it in some form.

quoted

Actually Abhijeet proposed such an API in 2011 but it didn't go
anywhere[1]. If we had that API we should be able to call
read_irq_line() from the pinctrl driver whenever we want to get the
state of the gpio, plus the API is generic. We're going to need that API
anyway for things like USB insertion detection so it might make sense to
add it sooner rather than later.

[1]
http://lists.infradead.org/pipermail/linux-arm-kernel/2011-April/048319.html

From what I can see of this thread it was exposed as a way for drivers
to be able to query if an interrupt handler was called on raising or
falling edge. And based on the locking limitations of the
implementation we couldn't have used it anyways.

Our use case is different in that we're at any point in time
interested in reading out the status of the irq line, as the only way
of getting that status.

How about using extcon framework? 

Regards,
Ivan