Re: adc-jack-driver opinion related to IIO

[Jonathan Cameron <jic23@cam.ac.uk>]

On 7/6/2012 1:00 PM, anish singh wrote:
> Hello Jonathan,
>
> I would be extremely happy if I can get your opinion on this.
>
> Recently Myungjoo Ham had posted Extcon: adc-jack driver patch.
>
> Description of this driver:
> This is basically a Headset(jack) driver.Once the headset is inserted
> a irq_handler is called and in this handler we have a callback(this
> callback calls into pmic driver to get the adc value) to get
> the adc value to determine the kind of headset: This headset could
> be headset with mic, headset without mic or headset with
> keys(volume-up/down) attached to it.One we have found out the kind
> of headset we use extcon framework to notify the other interested drivers or
> userspace that a headset with so and so capabilities has been inserted.
>
> Question:
> Does this driver fall into IIO as pointed by Mark Brown in his review comments?
The driver itself probably doesn't, but the adc part does in that IIO
provides a means of talking to the relevant adc.
>
> Why do we need to use IIO to get the adc value?As for different boards the
> method of getting adc is different.How does IIO help in this?
Ultimately, IIO in this case is acting as an infrastructure for ALL 
adcs. E.g. for different boards you'll need a mapping to tell it which
adc channel is connected but that is it.  Hence you don't need a 
specific callback for each pmic as you will be using generic interfaces 
to query it.

Jonathan