On Fri, Dec 07, 2018 at 09:07:19PM +0000, Abel Vesa wrote:
> On Fri, Dec 07, 2018 at 05:36:52PM +0100, Lucas Stach wrote:
> > Hi Abel,
> >
> > Am Freitag, den 07.12.2018, 16:17 +0000 schrieb Abel Vesa:
> > > On Fri, Nov 16, 2018 at 05:25:24PM -0600, Rob Herring wrote:
> > >
> > > > > +
> > > > > + clk_ext1: clock-ext1 {
> > > > > + compatible = "fixed-clock";
> > > > > + #clock-cells = <0>;
> > > > > + clock-frequency = <133000000>;
> > > > > + clock-output-names = "clk_ext1";
> > > > > + };
> > > > > +
> > > > > + clk_ext2: clock-ext2 {
> > > > > + compatible = "fixed-clock";
> > > > > + #clock-cells = <0>;
> > > > > + clock-frequency = <133000000>;
> > > > > + clock-output-names = "clk_ext2";
> > > > > + };
> > > > > +
> > > > > + clk_ext3: clock-ext3 {
> > > > > + compatible = "fixed-clock";
> > > > > + #clock-cells = <0>;
> > > > > + clock-frequency = <133000000>;
> > > > > + clock-output-names = "clk_ext3";
> > > > > + };
> > > > > +
> > > > > + clk_ext4: clock-ext4 {
> > > > > + compatible = "fixed-clock";
> > > > > + #clock-cells = <0>;
> > > > > + clock-frequency= <133000000>;
> > > > > + clock-output-names = "clk_ext4";
> > > > > + };
> > > >
> > > > This is really 4 independent clocks or is 1 clock connected to 4
> > > > sinks?
> > >
> > > According to the RM, yes, there are 4 independent clocks. Here is a
> > > link to the rm:
> > >
> > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.nxp.com%2Fwebapp%2FDownload%3FcolCode%3DIMX8MEVKBHUG&data=02%7C01%7Cabel.vesa%40nxp.com%7C303f3053feb94a3c1c9f08d65c623255%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636797974154936811&sdata=CuJSqDl1WiL%2Bc%2B4wYnr3ssDDpH3DorYIzLN87PNHVh4%3D&reserved=0 (page 829)
> > >
> > > Unfortunately, the old link (which worked without login) does not
> > > work anymore.
> >
> > It's really 4 clock inputs to the SoC, but they may actually be
> > connected to the same clock source on the board. So I really wonder if
> > we should even put this into the base SoC DT, but rather push this into
> > individual board DTs.
>
> Hmm, it's part of the SoC, right ? So I would keep it in the dtsi rather than
> having it duplicated into every new dts.
>
On a second thought, you're right, they seem to be input from the board and
would make sense to be in the board specific dts file.
Though, one problem with that is that the imx8mq CCM driver expects them to
be available.
One solution would be to keep as is since there is only one board (evk)
that is supported.
Later on, when another board comes around (and if it doesn't provide all the ext
clocks) we can rework the CCM driver to supoort that.
> >
> > Regards,
> > Lucas
>
> --
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