Re: [PATCH 3/4] arm64: dts: Add mediatek MT8173 SoC and evaluation board dts and Makefile

[Eddie Huang <eddie.huang@mediatek.com>]

Hi Matthias,

On Thu, 2014-12-11 at 14:02 +0100, Matthias Brugger wrote:
> Hi Eddie,
> 
> 2014-12-11 13:47 GMT+01:00 Eddie Huang <eddie.huang@mediatek.com>:
> > On Wed, 2014-12-10 at 15:50 +0100, Matthias Brugger wrote:
> >> 2014-12-10 15:27 GMT+01:00 Yingjoe Chen <yingjoe.chen@mediatek.com>:
> >> >
> >> > Hi,
> >> >
> >> > On Wed, 2014-12-10 at 18:50 +0800, Eddie Huang wrote:
> >> > <...>
> >> >> diff --git a/arch/arm64/boot/dts/mt8173-evb.dts b/arch/arm64/boot/dts/mt8173-evb.dts
> >> >> new file mode 100644
> >> >> index 0000000..adf26dd
> >> >> --- /dev/null
> >> >> +++ b/arch/arm64/boot/dts/mt8173-evb.dts
> >> > <...>
> >> >> +     timer {
> >> >> +             compatible = "arm,armv8-timer";
> >> >> +             interrupt-parent = <&gic>;
> >> >> +             interrupts = <1 13 0x8>,
> >> >> +                          <1 14 0x8>,
> >> >> +                          <1 11 0x8>,
> >> >> +                          <1 10 0x8>;
> >> >> +             clock-frequency = <13000000>;
> >> >
> >> > I believe our firmware doesn't need this line. Please remove it.
> >>
> >> The point here would be to know if you need to enable a special timer
> >> from the mtk-timer block to get the arch timer working.
> >> In any case, you will need some sort of timer. This dts does not
> >> describe the mtk-timer (may in the mt8173 it does not exist) but
> >> defines the clocks clk26m and clk32k. So if you don't use the
> >> mtk-timer, please remove the clocks as there isn't a block using them.
> >>
> >
> > MT8173 has two timer set: CPUGPT and APBGPT, and use CPUGPT to enable
> > arch_timer. Previous series only have APBGPT. MT8173 still need enable
> > CPUGPT to get arch timer working, we put this in loader, and transparent
> > to kernel. So I will remove clk26m and clk32k in next version.
> 
> Ok, so if this is done in the bootloader, there shouldn't be a problem
> then. Perfect.
> 
> Just one more comment on the dts nodes. Can you use the makros defined
> for the interrupt type
> e.g "GIC_PPI 14 IRQ_TYPE_LEVEL_LOW" instead of "1 14 0x8". This makes
> the dts easier to read.
> 
> Thanks,
> Matthias
> 

3.18 still don't have following patch
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/301425.html

So I can't use interrupt macro in mt8173.dtsi