Re: [EXT] Re: [PATCH 2/5] arm64: dts: lx2160a-rdb: remove useless property of rtc

From: Li Yang
Date: Tue Sep 22 2020 - 18:29:00 EST


On Mon, Sep 21, 2020 at 10:56 PM Biwen Li <biwen.li@xxxxxxx> wrote:
>
> >
> >
> >
> > > -----Original Message-----
> > > From: Biwen Li <biwen.li@xxxxxxx>
> > > Sent: Monday, September 21, 2020 10:13 PM
> > > To: Shawn Guo <shawnguo@xxxxxxxxxx>; Biwen Li (OSS)
> > > <biwen.li@xxxxxxxxxxx>
> > > Cc: alexandre.belloni@xxxxxxxxxxx; Leo Li <leoyang.li@xxxxxxx>;
> > > robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> > > linux-kernel@xxxxxxxxxxxxxxx; Jiafei Pan <jiafei.pan@xxxxxxx>; linux-
> > > rtc@xxxxxxxxxxxxxxx
> > > Subject: RE: [EXT] Re: [PATCH 2/5] arm64: dts: lx2160a-rdb: remove
> > > useless property of rtc
> > >
> > > >
> > > > Caution: EXT Email
> > > >
> > > > On Tue, Sep 15, 2020 at 03:32:10PM +0800, Biwen Li wrote:
> > > > > From: Biwen Li <biwen.li@xxxxxxx>
> > > > >
> > > > > Remove useless property interrupts of rtc
> > > > >
> > > > > Signed-off-by: Biwen Li <biwen.li@xxxxxxx>
> > > > > ---
> > > > > arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts | 2 --
> > > > > 1 file changed, 2 deletions(-)
> > > > >
> > > > > diff --git a/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > > > b/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > > > index dce79018d397..e9e982176e07 100644
> > > > > --- a/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > > > +++ b/arch/arm64/boot/dts/freescale/fsl-lx2160a-rdb.dts
> > > > > @@ -171,8 +171,6 @@
> > > > > rtc@51 {
> > > > > compatible = "nxp,pcf2129";
> > > > > reg = <0x51>;
> > > > > - // IRQ10_B
> > > > > - interrupts = <0 150 0x4>;
> > > >
> > > > If it's a correct description of hardware, I do not see why we would
> > > > need to remove it.
> > > Hi Shawn,
> > >
> > > Don't need use the interrupt, only read time from rtc.
> >
> > User probably will choose to use the alarm feature of the RTC and need the
> > interrupt property. Is there any issue when the interrupt property is present?
> Generic interrupt controller on layerscape only support IRQ_TYPE_LEVEL_HIGH and IRQ_TYPE_EDGE_RISING(except SoC LS1043A, LS1046A),
> Not support IRQ_TYPE_LEVEL_LOW,

That is not true. Although the GIC SPI only deals with level high and
rising edge, there is a separate IRQCR register on LX2160 that can
invert external interrupt. If the current LX2160 code doesn't support
that, we need to fix it. Adding Varun for this. We probably can
extend the existing drivers/irqchip/irq-ls-extirq.c driver to support
LX2160.

And btw, the interrupt number 150 is obviously wrong too. We probably
can remove it temporarily before the external interrupt is properly
supported on lx2160.

> In drivers/rtc/rtc-pcf2127.c
> ret = devm_request_threaded_irq(dev, alarm_irq, NULL,
> pcf2127_rtc_irq,
> IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> dev_name(dev), dev);
>
> >
> > >
> > > Best Regards,
> > > Biwen Li
> > > >
> > > > Shawn
> > > >
> > > > > };
> > > > > };
> > > > >
> > > > > --
> > > > > 2.17.1
> > > > >