[PATCH v2 03/19] fdt: Add function to look up a phandle's register address

Simon Glass sjg at chromium.org
Wed Jul 11 15:10:39 EST 2012


Hi Stephen,

On Fri, Jun 15, 2012 at 1:17 AM, Stephen Warren <swarren at wwwdotorg.org>wrote:

> On 06/13/2012 10:19 AM, Simon Glass wrote:
> > This is a commonly-used requirement, so add a function to support it
> > easily.
>
> Uggh. Why would this ever be needed; shouldn't the driver for the node
> referenced by the phandle fully control its own registers; why would any
> other driver randomly trample on them?
>

You are making assumptions. This is used for the pwm and only accessed by
the pwm driver.

It's basically to allow a simple and efficient way of getting access to a
peripheral. Since the new binding you pointed me to uses a single pwm with
multiple channels, this doesn't offer any benefit so I will punt it.

Regards,
Simon
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