Subject: Re: GPIO - marking individual pins (not) available in device tree

From: Matt Sealey <[email-masked]>
Date: Mon, 27 Oct 2008 10:40:12 -0500

David Gibson wrote:

> Um.. I can't actually follow what you're getting at there, sorry.

Imagine in your head that you have a GPIO controller that has a
32-bit register potentially controlling 32 pins on the chip.

Imagine that rather than being able to allocate 6 GPIO pins
*right next to each other* in the register and saying that
you start at "pin" 15 and use the next 6 "pins", you have to
spread it around and use pin 1, pin 8, pin 9, pin 11, pin 15,
pin 30, to make up this peripheral.

As far as I can tell there is no way at all to specify a set of
GPIO pins which are NOT consecutive because the current GPIO
spec stops after specifying a controller bank (the 32-bit
register).

-- 
Matt Sealey <[email-masked]>
Genesi, Manager, Developer Relations