Re: [PATCH v2] clk: Add driver for the si544 clock generator chip

[Mike Looijmans]

ïOn 18-03-18 13:52, Rob Herring wrote:
> On Thu, Mar 15, 2018 at 12:50:08PM +0100, Mike Looijmans wrote:
> > This patch adds the driver and devicetree documentation for the
> > Silicon Labs SI544 clock generator chip. This is an I2C controlled
> > oscillator capable of generating clock signals ranging from 200kHz
> > to 1500MHz.
> >
> > Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
> > ---
> > v2: Add u64 cast to ls_div_bits calculation loop
> >      When ls_div_bits is non-zero, the hs_div must always be even
> >
> >   .../devicetree/bindings/clock/silabs,si544.txt     |  25 ++
> >   drivers/clk/Kconfig                                |  10 +
> >   drivers/clk/Makefile                               |   1 +
> >   drivers/clk/clk-si544.c                            | 422 +++++++++++++++++++++
> >   4 files changed, 458 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/clock/silabs,si544.txt
> >   create mode 100644 drivers/clk/clk-si544.c
> >
> > diff --git a/Documentation/devicetree/bindings/clock/silabs,si544.txt b/Documentation/devicetree/bindings/clock/silabs,si544.txt
> > new file mode 100644
> > index 0000000..eec1787
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/silabs,si544.txt
> > @@ -0,0 +1,25 @@
> > +Binding for Silicon Labs 544 programmable I2C clock generator.
> > +
> > +Reference
> > +This binding uses the common clock binding[1]. Details about the device can be
> > +found in the datasheet[2].
> > +
> > +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> > +[2] Si544 datasheet
> > +    https://www.silabs.com/documents/public/data-sheets/si544-datasheet.pdf
> > +
> > +Required properties:
> > + - compatible: One of "silabs,si514a", "silabs,si514b" "silabs,si514c" according
> > +               to the speed grade of the chip.
> > + - reg: I2C device address.
> > + - #clock-cells: From common clock bindings: Shall be 0.
> > +
> > +Optional properties:
> > + - clock-output-names: From common clock bindings. Recommended to be "si544".
>
> What's the point if there is only 1 clock output?

I have a board with 6 of these chips, and the clock registration fails if they 
don't have unique names. Providing a clock-output-names property was the 
easiest way around it.

Should I just omit the line or change the wording to reflect the above or is 
there a better solution (maybe I can use the DT node name as clock name in the 
driver, will look into that)

> > +
> > +Example:
> > +	si544: clock-generator@55 {
>
> clock-controller@55 is the standard node name.

I'll change and post patch v3

> > +		reg = <0x55>;
> > +		#clock-cells = <0>;
> > +		compatible = "silabs,si544b";
> > +	};
>
> Otherwise, for the binding:
>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>



Kind regards,

Mike Looijmans
System Expert

TOPIC Products
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E-mail: mike.looijmans@xxxxxxxxxxxxxxxxx
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