Compatible string best practices

Compatible string best practices

[Sören Brinkmann]

Hi,

I have a question regarding how a compatible string should be created.
The simple case is obvious:
 <IP-vendor>,<IP-type/name>-<IP-revision>

But what is the recommended string for a SOC specific implementation of
that IP? Let's say for
 <SOC-vendor>,<SOC-name>-<SOC-revision>
how would I assemble a compatible string to identify the SOC-specific
implementation of IP?
I think my biggest confusion is which vendor string to use in that case.
But in general I'm curious whether some best practice exists for these
cases.

I think what I've seen most is:
 <SOC-vendor>,<SOC-name>-<IP-type>

But one could probably argue whether to rather use IP-vendor, appending
all the revision strings, ...

	Thanks,
	Sören

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Re: Compatible string best practices

[Mark Rutland]

On Fri, May 23, 2014 at 04:03:06PM +0100, Sören Brinkmann wrote:
> Hi,

Hi,

> I have a question regarding how a compatible string should be created.
> The simple case is obvious:
>  <IP-vendor>,<IP-type/name>-<IP-revision>
> 
> But what is the recommended string for a SOC specific implementation of
> that IP? Let's say for
>  <SOC-vendor>,<SOC-name>-<SOC-revision>
> how would I assemble a compatible string to identify the SOC-specific
> implementation of IP?
> I think my biggest confusion is which vendor string to use in that case.
> But in general I'm curious whether some best practice exists for these
> cases.
> 
> I think what I've seen most is:
>  <SOC-vendor>,<SOC-name>-<IP-type>
> 
> But one could probably argue whether to rather use IP-vendor, appending
> all the revision strings, ...

I would expect that the vendor prefix would be the last entity along the
chain which altered the IP in some way. Say foo sells device to bar, who
do nothing other than sell it to baz who do some hacks to integrate it.
For that I'd expect something like:

compatible = "baz,soc-device", "foo,device";

I'm not sure with revisions (they're not always that useful), but I'd
expect that to be kept next to the element it represent the revision
for:

"baz,soc-vX-device-vY", "bar,soc-device-vY", "foo,device-vY",
"foo,device-vY";

Cheers,
Mark.
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Re: Compatible string best practices

[Sören Brinkmann]

On Fri, 2014-05-23 at 05:03PM +0100, Mark Rutland wrote:
> On Fri, May 23, 2014 at 04:03:06PM +0100, Sören Brinkmann wrote:
> > Hi,
> 
> Hi,
> 
> > I have a question regarding how a compatible string should be created.
> > The simple case is obvious:
> >  <IP-vendor>,<IP-type/name>-<IP-revision>
> > 
> > But what is the recommended string for a SOC specific implementation of
> > that IP? Let's say for
> >  <SOC-vendor>,<SOC-name>-<SOC-revision>
> > how would I assemble a compatible string to identify the SOC-specific
> > implementation of IP?
> > I think my biggest confusion is which vendor string to use in that case.
> > But in general I'm curious whether some best practice exists for these
> > cases.
> > 
> > I think what I've seen most is:
> >  <SOC-vendor>,<SOC-name>-<IP-type>
> > 
> > But one could probably argue whether to rather use IP-vendor, appending
> > all the revision strings, ...
> 
> I would expect that the vendor prefix would be the last entity along the
> chain which altered the IP in some way. Say foo sells device to bar, who
> do nothing other than sell it to baz who do some hacks to integrate it.
> For that I'd expect something like:
> 
> compatible = "baz,soc-device", "foo,device";
> 
> I'm not sure with revisions (they're not always that useful), but I'd
> expect that to be kept next to the element it represent the revision
> for:
> 
> "baz,soc-vX-device-vY", "bar,soc-device-vY", "foo,device-vY",
> "foo,device-vY";

Thanks, Mark!

	Sören

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