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

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Hi Paul,

Sorry, I kind of forgot to answer that email.

On 10/13/2011 6:38 PM, 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.

Yeah, for me too, I think I did not get your concern...

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.

No, not for the same OMAP. The version is different for different OMAP version. So far the only IP with 2 different hwmod name for the same functionality is the timer. We have timer and timer_1ms, and that's for that kind of IP that we introduced the class to still be able to identify the functionality for the driver.

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

I still do not understand why we need that for the PRM.
AFAIK, we do have only one version of the PRM at the time. It is not similar to the timer case.

I'm still a little bit confused by your usecase.

You have only one PRM instance per OMAP. So you just have to do omap_hwmod_lookup("prm") to retrieve the relevant hwmod for the SoC.

If you need to build a different device per SoC to allow different driver to be bound to it, you can just append the version number to the hwmod name to build the device name.

Am I still missing something?

Regards,
Benoit

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