Re: [PATCHv9 03/18] TEMP: OMAP3xxx: hwmod data: add PRM hwmod

From: Paul Walmsley
Date: Thu Oct 13 2011 - 12:51:56 EST


On Thu, 13 Oct 2011, Paul Walmsley wrote:

> On Wed, 12 Oct 2011, Cousson, Benoit wrote:
>
> > On 10/11/2011 1:26 AM, Paul Walmsley wrote:
> > > On Tue, 11 Oct 2011, Cousson, Benoit wrote:
> > >
> > > > In fact the device name does not have to match the hwmod name. So we
> > > > can just create an "omap2_prm" omap_device for OMAP2, "omap3_prm"
> > > > omap_device for OMAP3... That will allow the relevant PRM driver to
> > > > be bound to the proper device.
> > >
> > > Incidentally, given that we would be using the hwmod name and the version
> > > number to determine the appropriate omap_device name, what IP version
> > > numbers should we assign to these PRM IP blocks for different SoCs?
> >
> > It can just be 1, 2 and 3... The idea is just to differentiate the IP for each
> > OMAP.
>
> So those are basically arbitrary? Something is not clear here.
>
> In the current hwmod design, IP blocks with different interfaces were
> intended to be uniquely identified by the hwmod name alone. That is why
> omap_hwmod_lookup() only takes a 'name' parameter.
>
> If I understand what you want to do, you wish to change this to uniquely
> identify them by a (name, interface version number) tuple.
>
> I don't have a problem with this in theory, but it implies some changes to
> the existing model. Specifically:
>
> - we'll need to add an interface version number to the struct omap_hwmod
>
> - we'll need to modify omap_hwmod_lookup() to take an interface version
> number
>
> - the "ti,hwmod" DT binding that you proposed earlier will need to include
> an interface version number

Hmm, reflecting on this further, is your intention to bind drivers to
hwmods by the struct omap_hwmod_class instead?

If we define that "rev" field as the interface version number, that should
probably work.

So then in C struct format, in a platform_device system, the mapping table
would basically become

struct omap_hwmod_driver_map {
const char *class_name;
const u32 class_rev;
const char *platform_device_name;
}

- Paul
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