Hi Linus, Thanks for review. On Sun, Apr 03, 2016 at 09:23:42PM +0200, Linus Walleij wrote: > On Sat, Apr 2, 2016 at 11:29 AM, Guodong Xu <guodong.xu@xxxxxxxxxx> wrote: > > > From: Leo Yan <leo.yan@xxxxxxxxxx> > > > > Add sp804 timer for hi6220, so it can be used as broadcast timer. > > > > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx> > > Signed-off-by: Wei Xu <xuwei5@xxxxxxxxxxxxx> > > --- > > arch/arm64/boot/dts/hisilicon/hi6220.dtsi | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/arch/arm64/boot/dts/hisilicon/hi6220.dtsi b/arch/arm64/boot/dts/hisilicon/hi6220.dtsi > > index ad1f1eb..82c4756 100644 > > --- a/arch/arm64/boot/dts/hisilicon/hi6220.dtsi > > +++ b/arch/arm64/boot/dts/hisilicon/hi6220.dtsi > > @@ -209,5 +209,14 @@ > > clock-names = "uartclk", "apb_pclk"; > > status = "disabled"; > > }; > > + > > + dual_timer0: dual_timer@f8008000 { > > + compatible = "arm,sp804", "arm,primecell"; > > + reg = <0x0 0xf8008000 0x0 0x1000>; > > + interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>, > > + <GIC_SPI 15 IRQ_TYPE_LEVEL_HIGH>; > > + clocks = <&ao_ctrl 27>; > > + clock-names = "apb_pclk"; > > How can this work? You only give the apb_pclk for clocking the > bus to the timer. > > Most platforms using this driver has something like this: > > timer01: timer@10104000 { > compatible = "arm,sp804", "arm,primecell"; > reg = <0x10104000 0x1000>; > interrupt-parent = <&intc_dc1176>; > interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>, <0 9 > IRQ_TYPE_LEVEL_HIGH>; > clocks = <&timclk>, <&timclk>, <&pclk>; > clock-names = "timer1", "timer2", "apb_pclk"; > }; > > It then reads the two clocks in the beginning of clocks() to > determine the frequency of each timer. > > By chance the code in the driver will allow just one clock and > will then assume that both the bus to the timer and the timer > itself is clocked from the same clock. But I highly doubt that this > is the case. This patch has been sent out for review previously [1]; So I refered other platforms and changed to only enable apb bus clock due I have not found timer enabling bits in Hi6220's spec. > Please verify what clocks actually goes into this timer, it should > nominally be three of them. Yes, it can work well even I don't enable any timer clock. I will check furthermore in spec to see if can bind with formal way as your suggestion. [1] http://archive.arm.linux.org.uk/lurker/message/20151009.131015.687ed525.en.html Thanks, Leo Yan -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html