Re: [PATCH v5 3/3] ARM: dts: igep00x0: add wl18xx bindings

Arnd Bergmann
2015-03-11T09:54:12Z

On Wednesday 11 March 2015 02:00:59 Javier Martinez Canillas wrote:
> Hello Tony,
>
> On Tue, Mar 10, 2015 at 6:35 PM, Tony Lindgren <tony@atomide.com> wrote:
> >>
> >> we do have to make sure these wl18xx bindings are future-compatible
> >> with the wl12xx ones, but i think the current bindings are pretty much
> >> standard (and are actually a subset of the bindings needed by wl12xx),
> >> so it should be fine.
> >
> > Well how about add just the parsing of the clock and assume it's always
> > WL12XX_REFCLOCK_38 for now as that's the only thing we're currently
> > using. Then we can add a property or compatible value if using something
> > else as needed.
> >
>
> What do you mean by parsing here? IIUC there isn't a clock driver for
> these clocks and are setup directly in the
> drivers/net/wireless/ti/wl12xx/main.c driver.
>
> So you can't make the WLAN chip dev node a consumer of these clocks by
> adding a phandle to a clock provider and clock specifiers since there
> isn't a provider to be referenced in the DT. Or did I misunderstand?

As I understand it, the clock signal is provided by an external oscillator,
which we can easily model in DT, and then you call clk_get_rate on that.

If there is no external clock provider for this chip and the clocks
are provided by the device itself, then all we need is a clock-frequency
property in the device node.

Arnd