[PATCH v5 1/3] iio: hx711: add clock-frequency property in DT

[PATCH v5 1/3] iio: hx711: add clock-frequency property in DT

[Andreas Klinger]

Add clock-frequency property for hx711 ADC. This is the frequency of
PD_SCK.

After PD_SCK goes high DOUT is read just before PD_SCK goes down again.
This is necessary because of parasitic capacitance on the wiring.

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
---
 Documentation/devicetree/bindings/iio/adc/avia-hx711.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt b/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt
index b3629405f568..2c1b67d33c49 100644
--- a/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt
+++ b/Documentation/devicetree/bindings/iio/adc/avia-hx711.txt
@@ -8,11 +8,17 @@ Required properties:
 		See Documentation/devicetree/bindings/gpio/gpio.txt
  - avdd-supply:	Definition of the regulator used as analog supply
 
+Optional properties:
+ - clock-frequency:	Frequency of PD_SCK in Hz
+			Minimum value allowed is 10 kHz because of maximum
+			high time of 50 microseconds.
+
 Example:
 weight@0 {
 	compatible = "avia,hx711";
 	sck-gpios = <&gpio3 10 GPIO_ACTIVE_HIGH>;
 	dout-gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>;
 	avdd-suppy = <&avdd>;
+	clock-frequency = <100000>;
 };
 
-- 
2.1.4

Re: [PATCH v5 1/3] iio: hx711: add clock-frequency property in DT

[Rob Herring]

On Tue, Jul 10, 2018 at 08:18:31PM +0200, Andreas Klinger wrote:
> Add clock-frequency property for hx711 ADC. This is the frequency of
> PD_SCK.
> 
> After PD_SCK goes high DOUT is read just before PD_SCK goes down again.
> This is necessary because of parasitic capacitance on the wiring.
> 
> Signed-off-by: Andreas Klinger <ak@it-klinger.de>
> ---
>  Documentation/devicetree/bindings/iio/adc/avia-hx711.txt | 6 ++++++
>  1 file changed, 6 insertions(+)

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v5 1/3] iio: hx711: add clock-frequency property in DT

[Jonathan Cameron]

On Wed, 11 Jul 2018 07:54:00 -0600
Rob Herring <robh@kernel.org> wrote:

> On Tue, Jul 10, 2018 at 08:18:31PM +0200, Andreas Klinger wrote:
> > Add clock-frequency property for hx711 ADC. This is the frequency of
> > PD_SCK.
> > 
> > After PD_SCK goes high DOUT is read just before PD_SCK goes down again.
> > This is necessary because of parasitic capacitance on the wiring.
> > 
> > Signed-off-by: Andreas Klinger <ak@it-klinger.de>
> > ---
> >  Documentation/devicetree/bindings/iio/adc/avia-hx711.txt | 6 ++++++
> >  1 file changed, 6 insertions(+)  
> 
> Reviewed-by: Rob Herring <robh@kernel.org>
Applied to the togreg branch of iio.git and pushed out as testing.

Thanks,

Jonathan

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