Re: [PATCH 1/3] arm64: dts: actions: add s900 clock controller nodes

From: Manivannan Sadhasivam
Date: Sat Nov 04 2017 - 05:02:54 EST


Hi Rob,
On Wed, Nov 01, 2017 at 07:06:16PM -0500, Rob Herring wrote:
> On Wed, Nov 01, 2017 at 01:24:21AM +0530, Manivannan Sadhasivam wrote:
> > This patch adds clock controller nodes for Actions Semi s900 SoC
> >
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/actions/s900.dtsi | 19 +++++++++++++++++++
> > 1 file changed, 19 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/actions/s900.dtsi b/arch/arm64/boot/dts/actions/s900.dtsi
> > index 11406f6..c099ef1 100644
> > --- a/arch/arm64/boot/dts/actions/s900.dtsi
> > +++ b/arch/arm64/boot/dts/actions/s900.dtsi
> > @@ -5,6 +5,7 @@
> > */
> >
> > #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +#include <dt-bindings/clock/actions,s900-clock.h>
> >
> > / {
> > compatible = "actions,s900";
> > @@ -88,6 +89,24 @@
> > #clock-cells = <0>;
> > };
> >
> > + losc: losc {
> > + compatible = "fixed-clock";
> > + clock-frequency = <32768>;
> > + #clock-cells = <0>;
> > + };
> > +
> > + diff_24M: diff_24M {
> > + compatible = "fixed-clock";
> > + clock-frequency = <24000000>;
> > + #clock-cells = <0>;
> > + };
>
> These 2 are inputs to the clock ctrlr? The clock controller should have
> a clocks property then.
>
Actually losc and hosc (already defined) are the sources to the clock
controller. There isn't much documentation about diff_24M clock which
seems to be only sourcing eDP. Since, the vendor driver defined these
3 clocks (losc, hosc, diff_24M) as fixed rate clocks I have added them
in the device tree as "fixed-clock" nodes.

So, as per your suggestion I will add hosc and losc as clock providers
for the clock controller like below in next revision:

clocks = <&hosc>, <&losc>;

Thanks,
Mani
> > +
> > + clock: clock-controller@e0160000 {
> > + compatible = "actions,s900-clock";
> > + reg = <0 0xe0160000 0 0x1000>;
> > + #clock-cells = <1>;
> > + };
> > +
> > soc {
> > compatible = "simple-bus";
> > #address-cells = <2>;
> > --
> > 2.7.4
> >