Re: [PATCHv2 3/3] Documentation: DT bindings: Tegra AHB: note base address change

Paul Walmsley
2015-03-19T16:46:22Z

On Thu, 19 Mar 2015, Paul Walmsley wrote:

> On Thu, 19 Mar 2015, Stephen Warren wrote:
>
> > On 03/19/2015 09:26 AM, Paul Walmsley wrote:
> > > On Tue, 17 Mar 2015, Russell King - ARM Linux wrote:
> > >
> > > > On Tue, Mar 17, 2015 at 01:32:21AM -0700, Paul Walmsley wrote:
> > > > > Required properties:
> > > > > - compatible : For Tegra20, must contain "nvidia,tegra20-ahb". For
> > > > > - Tegra30, must contain "nvidia,tegra30-ahb". Otherwise, must contain
> > > > > - '"nvidia,<chip>-ahb", "nvidia,tegra30-ahb"' where <chip> is tegra124,
> > > > > - tegra132, or tegra210.
> > > > > -- reg : Should contain 1 register ranges(address and length)
> > > > > + Tegra30, must contain "nvidia,tegra30-ahb". For Tegra114 and
> > > > > Tegra124, must
> > > > > + contain '"nvidia,<chip>-ahb", "nvidia,tegra30-ahb"' where <chip> is
> > > > > tegra114
> > > > > + or tegra124. For Tegra132, the compatible string must contain
> > > > > + "nvidia,tegra132-ahb".
> > > > > +
> > > > > +- reg : Should contain 1 register ranges(address and length). On
> > > > > Tegra20,
> > > > > + Tegra30, Tegra114, and Tegra124 chips, the low byte of the physical
> > > > > base
> > > > > + address of the IP block must end in 0x04. On DT files for later
> > > > > chips, the
> > > > > + actual hardware base address of the IP block should be used.
> > > >
> > > > You could check that in the driver. If you can check it in the driver,
> > > > you can also decide to ignore it if it were offset by 0x04 (possibly
> > > > printing a warning.) That opens up the ability to fix the older Tegra
> > > > DT files going forward while still remaining compatible with existing
> > > > DT files, and avoiding the need for a complex note about this.
> > >
> > > That's fine, I'll do that and drop this patch.
> >
> > Don't we still want to update the DT binding documentation to state what the
> > preferred base address (or at least set of legal base addresses) is/are?
>
> As far as I know, the DT binding documents are intended to be a
> reference for IP block integration data like base addresses.

The above is missing an important word: it should have read "are _not_
intended"

- Paul