Hi Geert,

On Friday, April 28, 2017, Geert Uytterhoeven wrote:
> >> Shouldn't the interrupt (connected to P1_15) be described?
> >
> > That interrupt pin from the PHY is not used. It did not need to be
> connected.
> 
> But it is connected, according to the schematics.

P1_15 can be configured as:
 * GPIO_IN
 * AN7
 * AVB_CAPTURE

So...I guess you would 'describe' it as an GPIO-input.


> DT describes hardware, not software limitations.

Describing things is fine, but the kernel code takes the DT and then start 
configuring things based on it.

For example, on the RSK board, that line is connected to P4_14. P4_14 can be 
configured as IRQ6...but IRQ6 comes out in 8 different pin choices, and I might 
want to use one of those other choices, so I don't want to describe P4_14 as an 
interrupt.

If it was just describing that "pin 15 of the PHY chip is tied to pin Y19 of 
the RZ/A1H", that's fine because it's hardware connection that's not going to 
change.
But...the DT also defines the pin muxing...which is a software decision (do I 
want to get interrupt or just manually poll or simple ignore it).
This is the part of the whole "DT is for hardware description only" that 
doesn't really make sense to me.


Chris

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