Messages in this thread | | | From | Yash Shah <> | Date | Thu, 24 Jan 2019 14:28:44 +0530 | Subject | Re: [PATCH v4 1/2] pwm: sifive: Add DT documentation for SiFive PWM Controller |
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On Mon, Jan 21, 2019 at 8:29 PM Rob Herring <robh@kernel.org> wrote: > > On Mon, Jan 21, 2019 at 03:50:42PM +0530, Yash Shah wrote: > > DT documentation for PWM controller added. > > > > Signed-off-by: Wesley W. Terpstra <wesley@sifive.com> > > [Atish: Compatible string update] > > Signed-off-by: Atish Patra <atish.patra@wdc.com> > > Signed-off-by: Yash Shah <yash.shah@sifive.com> > > --- > > .../devicetree/bindings/pwm/pwm-sifive.txt | 37 ++++++++++++++++++++++ > > 1 file changed, 37 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/pwm/pwm-sifive.txt > > > > diff --git a/Documentation/devicetree/bindings/pwm/pwm-sifive.txt b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt > > new file mode 100644 > > index 0000000..b207908 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt > > @@ -0,0 +1,37 @@ > > +SiFive PWM controller > > + > > +Unlike most other PWM controllers, the SiFive PWM controller currently only > > +supports one period for all channels in the PWM. This is set globally in DTS. > > +The period also has significant restrictions on the values it can achieve, > > +which the driver rounds to the nearest achievable frequency. > > + > > +Required properties: > > +- compatible: Should be "sifive,pwmX" and "sifive,$socname-pwm". > > The order here is wrong.
Will fix the order.
> > You still need to enumeration valid version numbers. Is 'sifive,pwm20' > valid?
Yes
> > > + Please refer to sifive-blocks-ip-versioning.txt for details. > > +- reg: physical base address and length of the controller's registers > > +- clocks: Should contain a clock identifier for the PWM's parent clock. > > +- #pwm-cells: Should be 2. > > + Refer to bindings/pwm/pwm.txt for details. > > +- sifive,period-ns: the driver will get as close to this period as it can > > +- interrupts: one interrupt per PWM channel > > How many channels? If variable, is the a max number?
Max 4 channels.
> > > + > > +PWM RTL that corresponds to the IP block version numbers can be found > > +here: > > + > > +https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/pwm > > Put this in the description at the top.
Sure.
> > > + > > +Further information on the format of the IP > > +block-specific version numbers can be found in > > +Documentation/devicetree/bindings/sifive/sifive-blocks-ip-versioning.txt > > You already said this.
Will remove redundant info.
> > > + > > +Examples: > > + > > +pwm: pwm@10020000 { > > + compatible = "sifive,fu540-c000-pwm","sifive,pwm0"; > > Space after the ',' needed.
Sure
> > > + reg = <0x0 0x10020000 0x0 0x1000>; > > + clocks = <&tlclk>; > > + interrupt-parent = <&plic>; > > + interrupts = <42 43 44 45>; > > + #pwm-cells = <2>; > > + sifive,period-ns = <1000000>; > > +}; > > -- > > 1.9.1 > >
Thanks for the feedback
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