RE: [PATCH v3 1/2] dt-bindings: timer: Add bindings for Intel Keem Bay SoC Timer

From: Sanil, Shruthi
Date: Tue Jun 08 2021 - 02:13:46 EST


> -----Original Message-----
> From: Sanil, Shruthi
> Sent: Thursday, June 3, 2021 5:02 PM
> To: 'Rob Herring' <robh@xxxxxxxxxx>
> Cc: daniel.lezcano@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> andriy.shevchenko@xxxxxxxxxxxxxxx; kris.pan@xxxxxxxxxxxxxxx;
> mgross@xxxxxxxxxxxxxxx; Thokala, Srikanth <Srikanth.Thokala@xxxxxxxxx>;
> Raja Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@xxxxxxxxx>;
> Sangannavar, Mallikarjunappa <mallikarjunappa.sangannavar@xxxxxxxxx>
> Subject: RE: [PATCH v3 1/2] dt-bindings: timer: Add bindings for Intel Keem
> Bay SoC Timer
>
> Hi Rob,
>
> > -----Original Message-----
> > From: Rob Herring <robh@xxxxxxxxxx>
> > Sent: Thursday, June 3, 2021 12:52 AM
> > To: Sanil, Shruthi <shruthi.sanil@xxxxxxxxx>
> > Cc: daniel.lezcano@xxxxxxxxxx; tglx@xxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> > andriy.shevchenko@xxxxxxxxxxxxxxx; kris.pan@xxxxxxxxxxxxxxx;
> > mgross@xxxxxxxxxxxxxxx; Thokala, Srikanth
> > <srikanth.thokala@xxxxxxxxx>; Raja Subramanian, Lakshmi Bai
> > <lakshmi.bai.raja.subramanian@xxxxxxxxx>;
> > Sangannavar, Mallikarjunappa <mallikarjunappa.sangannavar@xxxxxxxxx>
> > Subject: Re: [PATCH v3 1/2] dt-bindings: timer: Add bindings for Intel
> > Keem Bay SoC Timer
> >
> > On Thu, May 27, 2021 at 12:09:05PM +0530, shruthi.sanil@xxxxxxxxx
> wrote:
> > > From: Shruthi Sanil <shruthi.sanil@xxxxxxxxx>
> > >
> > > Add Device Tree bindings for the Timer IP, which can be used as
> > > clocksource and clockevent device in the Intel Keem Bay SoC.
> > >
> > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
> > > Signed-off-by: Shruthi Sanil <shruthi.sanil@xxxxxxxxx>
> > > ---
> > > .../bindings/timer/intel,keembay-timer.yaml | 180
> ++++++++++++++++++
> > > 1 file changed, 180 insertions(+)
> > > create mode 100644
> > > Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> > > b/Documentation/devicetree/bindings/timer/intel,keembay-timer.yaml
> > > new file mode 100644
> > > index 000000000000..e0152e19208f
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/timer/intel,keembay-
> > timer.yaml
> > > @@ -0,0 +1,180 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/timer/intel,keembay-timer.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Intel Keem Bay SoC Timers
> > > +
> > > +maintainers:
> > > + - Shruthi Sanil <shruthi.sanil@xxxxxxxxx>
> > > +
> > > +description: |
> > > + The Intel Keem Bay timer driver supports clocksource and
> > > +clockevent
> > > + features for the timer IP used in Intel Keembay SoC.
> > > + The timer block supports 1 free running counter and 8 timers.
> > > + The free running counter can be used as a clocksouce and
> > > + the timers can be used as clockevent. Each timer is capable of
> > > + generating inividual interrupt.
> > > + Both the features are enabled through the timer general config
> register.
> > > +
> > > + The parent node represents the common general configuration
> > > + details and the child nodes represents the counter and timers.
> > > +
> > > +properties:
> >
> > There's no compatible, so this schema will never be applied. You need
> > a compatible to identify what the block is.
> >
>
> This is a parent block that has the common configuration register address
> defined which we would need during the initialization of the child nodes.
> This block in itself is not doing anything. We have this because, we have a
> common register that is required to be accessed during all the timers and
> counter initialization.
> The child nodes have the compatible string.
> I have validated this on the HW and see that the timer probes are being
> called and the timers are functional as expected.
> Please suggest if there is a better way to handle this scenario.
>

Could you please confirm if the existing approach is OK. This has been validated on Keem Bay evaluation HW and its working as expected.
Also please suggest if we have a better way to handle this.

Thanks & Regards,
Shruthi

> > > + reg:
> > > + description: General configuration register address and length.
> > > + maxItems: 1
> > > +
> > > + "#address-cells":
> > > + const: 2
> > > +
> > > + "#size-cells":
> > > + const: 2
> >
> > Not really any reason for 64-bits of address space in the child nodes.
> > Use a non-empty ranges.
>
> OK, I'll remove it.
>
> >
> > > +
> > > + ranges: true
> > > +
> > > +required:
> > > + - compatible
> > > + - reg
> > > + - "#address-cells"
> > > + - "#size-cells"
> > > + - ranges
> > > +
> > > +patternProperties:
> > > + "^counter@[0-9a-f]+$":
> > > + type: object
> > > + description: Properties for Intel Keem Bay counter
> > > +
> > > + properties:
> > > + compatible:
> > > + enum:
> > > + - intel,keembay-counter
> > > +
> > > + reg:
> > > + maxItems: 1
> > > +
> > > + clocks:
> > > + maxItems: 1
> > > +
> > > + required:
> > > + - compatible
> > > + - reg
> > > + - clocks
> > > +
> > > + "^timer@[0-9a-f]+$":
> > > + type: object
> > > + description: Properties for Intel Keem Bay timer
> > > +
> > > + properties:
> > > + compatible:
> > > + enum:
> > > + - intel,keembay-timer
> > > +
> > > + reg:
> > > + maxItems: 1
> > > +
> > > + interrupts:
> > > + maxItems: 1
> > > +
> > > + clocks:
> > > + maxItems: 1
> > > +
> > > + required:
> > > + - compatible
> > > + - reg
> > > + - interrupts
> > > + - clocks
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > + - |
> > > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > + #include <dt-bindings/interrupt-controller/irq.h>
> > > + #define KEEM_BAY_A53_TIM
> > > +
> > > + soc {
> > > + #address-cells = <0x2>;
> > > + #size-cells = <0x2>;
> > > +
> > > + gpt@20331000 {
> > > + reg = <0x0 0x20331000 0x0 0xc>;
> > > + #address-cells = <0x2>;
> > > + #size-cells = <0x2>;
> > > + ranges;
> > > +
> > > + counter@203300e8 {
> > > + compatible = "intel,keembay-counter";
> > > + reg = <0x0 0x203300e8 0x0 0x8>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> >
> > Don't show status in examples.
>
> OK, I'll remove it.
>
> Thanks!
> Shruthi
>
> >
> > > + };
> > > +
> > > + timer@20330010 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330010 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x3 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330020 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330020 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x4 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330030 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330030 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x5 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330040 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330040 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x6 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330050 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330050 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x7 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330060 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330060 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x8 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330070 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330070 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0x9 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > +
> > > + timer@20330080 {
> > > + compatible = "intel,keembay-timer";
> > > + reg = <0x0 0x20330080 0x0 0xc>;
> > > + interrupts = <GIC_SPI 0xa IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&scmi_clk KEEM_BAY_A53_TIM>;
> > > + status = "okay";
> > > + };
> > > + };
> > > + };
> > > +
> > > +...
> > > --
> > > 2.17.1