[PATCH v6 1/3] dt-bindings: pwm: Add Xilinx AXI Timer

Rob Herring robh at kernel.org
Mon Sep 20 05:35:12 PDT 2021


On Thu, Sep 16, 2021 at 12:58 PM Sean Anderson <sean.anderson at seco.com> wrote:
>
>
>
> On 8/31/21 4:11 PM, Rob Herring wrote:
> > On Thu, Aug 26, 2021 at 05:18:28PM -0400, Sean Anderson wrote:
> >> This adds a binding for the Xilinx LogiCORE IP AXI Timer. This device is a
> >> "soft" block, so it has some parameters which would not be configurable in
> >> most hardware. This binding is usually automatically generated by Xilinx's
> >> tools, so the names and values of some properties should be kept as they
> >> are, if possible. In addition, this binding is already in the kernel at
> >> arch/microblaze/boot/dts/system.dts, and in user software such as QEMU.
> >>
> >> The existing driver uses the clock-frequency property, or alternatively the
> >> /cpus/timebase-frequency property as its frequency input. Because these
> >> properties are deprecated, they have not been included with this schema.
> >> All new bindings should use the clocks/clock-names properties to specify
> >> the parent clock.
> >>
> >> Because we need to init timer devices so early in boot, we determine if we
> >> should use the PWM driver or the clocksource/clockevent driver by the
> >> presence/absence, respectively, of #pwm-cells. Because both counters are
> >> used by the PWM, there is no need for a separate property specifying which
> >> counters are to be used for the PWM.
> >>
> >> Signed-off-by: Sean Anderson <sean.anderson at seco.com>
> >> ---
> >>
> >> Changes in v6:
> >> - Fix incorrect schema id
> >> - Enumerate possible counter widths
> >>
> >> Changes in v5:
> >> - Update commit message to reflect revisions
> >> - Fix indentation lint
> >> - Add example for timer binding
> >> - Remove xlnx,axi-timer-2.0 compatible string
> >> - Move schema into the timer directory
> >>
> >> Changes in v4:
> >> - Remove references to generate polarity so this can get merged
> >> - Predicate PWM driver on the presence of #pwm-cells
> >> - Make some properties optional for clocksource drivers
> >>
> >> Changes in v3:
> >> - Mark all boolean-as-int properties as deprecated
> >> - Add xlnx,pwm and xlnx,gen?-active-low properties.
> >> - Make newer replacement properties mutually-exclusive with what they
> >>   replace
> >> - Add an example with non-deprecated properties only.
> >>
> >> Changes in v2:
> >> - Use 32-bit addresses for example binding
> >>
> >>  .../bindings/timer/xlnx,xps-timer.yaml        | 90 +++++++++++++++++++
> >>  1 file changed, 90 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/timer/xlnx,xps-timer.yaml
> >>
> >> diff --git a/Documentation/devicetree/bindings/timer/xlnx,xps-timer.yaml b/Documentation/devicetree/bindings/timer/xlnx,xps-timer.yaml
> >> new file mode 100644
> >> index 000000000000..5be353a642aa
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/timer/xlnx,xps-timer.yaml
> >> @@ -0,0 +1,90 @@
> >> +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
> >> +%YAML 1.2
> >> +---
> >> +$id: http://devicetree.org/schemas/timer/xlnx,xps-timer.yaml#
> >> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >> +
> >> +title: Xilinx LogiCORE IP AXI Timer Device Tree Binding
> >> +
> >> +maintainers:
> >> +  - Sean Anderson <sean.anderson at seco.com>
> >> +
> >> +properties:
> >> +  compatible:
> >> +    contains:
> >> +      const: xlnx,xps-timer-1.00.a
> >> +
> >> +  clocks:
> >> +    maxItems: 1
> >> +
> >> +  clock-names:
> >> +    const: s_axi_aclk
> >> +
> >> +  interrupts:
> >> +    maxItems: 1
> >> +
> >> +  reg:
> >> +    maxItems: 1
> >> +
> >> +  xlnx,count-width:
> >> +    $ref: /schemas/types.yaml#/definitions/uint32
> >> +    enum: [8, 16, 32]
> >> +    default: 32
> >> +    description:
> >> +      The width of the counter(s), in bits.
> >> +
> >> +  xlnx,one-timer-only:
> >> +    $ref: /schemas/types.yaml#/definitions/uint32
> >> +    enum: [ 0, 1 ]
> >> +    description:
> >> +      Whether only one timer is present in this block.
> >> +
> >> +required:
> >> +  - compatible
> >> +  - reg
> >> +  - xlnx,one-timer-only
> >> +
> >> +allOf:
> >> +  - if:
> >> +      required:
> >> +        - '#pwm-cells'
> >> +    then:
> >> +      allOf:
> >> +        - required:
> >> +            - clocks
> >> +        - properties:
> >> +            xlnx,one-timer-only:
> >> +              const: 0
> >> +    else:
> >> +      required:
> >> +        - interrupts
> >> +  - if:
> >> +      required:
> >> +        - clocks
> >> +    then:
> >> +      required:
> >> +        - clock-names
> >> +
> >> +additionalProperties: true
> >
> > This needs to be false. What else do you expect to be present?
>
> I am going to leave this as true for the next revision to avoid the following error:
>
> arch/microblaze/boot/dts/system.dt.yaml: timer at 83c00000: 'xlnx,family', 'xlnx,gen0-assert', 'xlnx,gen1-assert', 'xlnx,trig0-assert', 'xlnx,trig1-assert' do not match any of the regexes: 'pinctrl-[0-9]+'

If I wasn't clear: NAK

All properties must be documented or removed from .dts files if not needed.

Rob



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