Re: [PATCH 1/4] arm64: dts: exynos: Add PWM interrupts on Exynos7

From: 'Krzysztof Kozlowski'
Date: Thu Jul 02 2020 - 02:00:15 EST


On Tue, Jun 30, 2020 at 08:54:28PM +0530, Alim Akhtar wrote:
> Hi Krzysztof,
>
> > -----Original Message-----
> > From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > Sent: 30 June 2020 02:15
> > To: Rob Herring <robh+dt@xxxxxxxxxx>; Kukjin Kim <kgene@xxxxxxxxxx>;
> > Krzysztof Kozlowski <krzk@xxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx;
> linux-arm-
> > kernel@xxxxxxxxxxxxxxxxxxx; linux-samsung-soc@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx
> > Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>; Bartlomiej Zolnierkiewicz
> > <b.zolnierkie@xxxxxxxxxxx>; Sylwester Nawrocki <snawrocki@xxxxxxxxxx>;
> > Alim Akhtar <alim.akhtar@xxxxxxxxxxx>; Chanwoo Choi
> > <cw00.choi@xxxxxxxxxxx>; Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> > Subject: [PATCH 1/4] arm64: dts: exynos: Add PWM interrupts on Exynos7
> >
> > Add required interrupts to PWM node on Exynos7. This fixes DT schema
> > warning:
> >
> > pwm@136c0000: 'interrupts' is a required property
> >
> > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> >
> > ---
> >
> > Not tested
> > ---
> > arch/arm64/boot/dts/exynos/exynos7.dtsi | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/exynos/exynos7.dtsi
> > b/arch/arm64/boot/dts/exynos/exynos7.dtsi
> > index f590891efe25..523547b3d539 100644
> > --- a/arch/arm64/boot/dts/exynos/exynos7.dtsi
> > +++ b/arch/arm64/boot/dts/exynos/exynos7.dtsi
> > @@ -581,6 +581,11 @@
> > pwm: pwm@136c0000 {
> > compatible = "samsung,exynos4210-pwm";
> > reg = <0x136c0000 0x100>;
> > + interrupts = <GIC_SPI 444 IRQ_TYPE_LEVEL_HIGH>,
> > + <GIC_SPI 445 IRQ_TYPE_LEVEL_HIGH>,
> > + <GIC_SPI 446 IRQ_TYPE_LEVEL_HIGH>,
> > + <GIC_SPI 447 IRQ_TYPE_LEVEL_HIGH>,
> > + <GIC_SPI 448 IRQ_TYPE_LEVEL_HIGH>;
> PWM IRQs are from 449 ~ 453 for PWM[0] ~ PWM[4] on this SoC.
> 444 ~ 447 are for HSI2C and 448 is for ADC.

Ah, indeed.

> Please see the exynos7.dtsi
> Also drivers/pwm/pwm-samsung.c does not uses interrupt at all, still we need
> interrupts property to be added here?

That's a good point. For S3C SoCs the PWM timer was used also as a
clocksource so it required interrupts. But since Exynos this is not
used. I don't know why the bindings introduced required interrupts...
It seems it would be better just to remove them from bindings and DTS.

Best regards,
Krzysztof