[PATCHv3 1/4] mfd: smsc: Add support for smsc gpio io/keypad driver

Mark Brown broonie at opensource.wolfsonmicro.com
Tue Oct 2 22:58:20 EST 2012


On Tue, Oct 02, 2012 at 03:43:22PM +0300, Felipe Balbi wrote:

> BTW, OTOH writing all children into the DT actually describes the HW,
> no ? And depending on the device I feel it'd be better to write that

Well, it depends on the hardware.  Some hardware has a bunch of nice,
neat IPs which can usefully be reproduced and which map sensibly onto OS
abstractions but a lot of it doesn't and frequently the abstractions
which Linux wants to use don't bear a huge resemblance to the hardware
(and Linux's ideas can change over time, as with the clock API being
factored out for example).

> data to DT. Think of twlxxxx (TI's PMICs), we might have completely
> unrelated drivers using one of TWL's GPIO lines as an interrupt source.

> If that particular children isn't listed in DT, it can't be used as an
> interrupt-parent, right ?

You can have the interrupt controller there without having to list every
IP in the device, just make the parent device the interrupt controller
to DT.


More information about the devicetree-discuss mailing list