[PATCH v2] arm64: dts: imx8mp: Add DT nodes for the two ISPs

[Peng Fan]

> Subject: Re: [PATCH v2] arm64: dts: imx8mp: Add DT nodes for the two ISPs
> > >
> > > > Something like
> > > > ---8<---
> > > > --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> > > > +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
> > > > @@ -1837,11 +1837,13 @@ media_blk_ctrl: blk-ctrl at 32ec0000 {
> > > >                                                   <&clk IMX8MP_CLK_MEDIA_APB>,
> > > >                                                   <&clk IMX8MP_CLK_MEDIA_DISP1_PIX>,
> > > >                                                   <&clk
> > > > IMX8MP_CLK_MEDIA_DISP2_PIX>,
> > > > +                                                 <&clk
> > > > + IMX8MP_CLK_MEDIA_ISP>,
> > > >                                                   <&clk IMX8MP_VIDEO_PLL1>;
> > > >                                 assigned-clock-parents = <&clk
> IMX8MP_SYS_PLL2_1000M>,
> > > >                                                          <&clk IMX8MP_SYS_PLL1_800M>,
> > > >                                                          <&clk IMX8MP_VIDEO_PLL1_OUT>,
> > > > -                                                        <&clk IMX8MP_VIDEO_PLL1_OUT>;
> > > > +                                                        <&clk IMX8MP_VIDEO_PLL1_OUT>,
> > > > +                                                        <&clk
> > > > + IMX8MP_SYS_PLL2_500M>;
> > > >                                 assigned-clock-rates = <500000000>, <200000000>,
> > > >                                                        <0>, <0>,
> > > > <1039500000>;
> > >
> 
> According to the i.MX8MP Data sheet, the nominal speed for
> MEDIA_ISP_CLOCL_ROOT is 400MHZ with 500MHz being allowed in
> overdrive mode.
> 
> I think this clock rate should drop to  the nominal value of 400MHz and those
> boards who support overdrive can increase it to 500MHz to avoid stiability
> issues and/or running out of spec.  I created an imx8mm and imx8mn-
> overdrive.dtsi file.  If there is interest, I can do the same for the 8MP as well.
> 
> I haven't gone through all the clocks to determine if/what clocks are being
> overdriven.

Shouldn't the bootloader take the work to runtime update the freq?
Why need introduce an extra overdrive.dtsi?

Thanks,
Peng.