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Message-ID: <YW2kLjjbAYdaDI0l@robh.at.kernel.org>
Date: Mon, 18 Oct 2021 11:43:26 -0500
From: Rob Herring <robh@...nel.org>
To: Sean Anderson <sean.anderson@...o.com>
Cc: linux-arm-kernel@...ts.infradead.org,
Thierry Reding <thierry.reding@...il.com>,
linux-kernel@...r.kernel.org,
Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>,
Alvaro Gamez <alvaro.gamez@...ent.com>,
devicetree@...r.kernel.org, Lee Jones <lee.jones@...aro.org>,
michal.simek@...inx.com, linux-pwm@...r.kernel.org
Subject: Re: [PATCH v8 2/3] dt-bindings: pwm: Add Xilinx AXI Timer
On Fri, 15 Oct 2021 15:00:24 -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@...o.com>
> ---
>
> Changes in v8:
> - Set additionalProperties: false
>
> Changes in v7:
> - Add #pwm-cells to properties
> - Document why additionalProperties is true
>
> Changes in v6:
> - Enumerate possible counter widths
> - Fix incorrect schema id
>
> Changes in v5:
> - Add example for timer binding
> - Fix indentation lint
> - Move schema into the timer directory
> - Remove xlnx,axi-timer-2.0 compatible string
> - Update commit message to reflect revisions
>
> Changes in v4:
> - Make some properties optional for clocksource drivers
> - Predicate PWM driver on the presence of #pwm-cells
> - Remove references to generate polarity so this can get merged
>
> Changes in v3:
> - Add an example with non-deprecated properties only.
> - Add xlnx,pwm and xlnx,gen?-active-low properties.
> - Make newer replacement properties mutually-exclusive with what they
> replace
> - Mark all boolean-as-int properties as deprecated
>
> Changes in v2:
> - Use 32-bit addresses for example binding
>
> .../bindings/timer/xlnx,xps-timer.yaml | 92 +++++++++++++++++++
> 1 file changed, 92 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/timer/xlnx,xps-timer.yaml
>
Reviewed-by: Rob Herring <robh@...nel.org>
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