Re: [PATCH 5/5] dt-bindings: iio: Add adis16475 documentation

["Sa, Nuno" <Nuno.Sa@analog.com>]

On Tue, 2020-03-03 at 09:43 +0000, Sa, Nuno wrote:
> [External]
> 
> On Mon, 2020-03-02 at 16:22 -0600, Rob Herring wrote:
> > On Tue, Feb 25, 2020 at 01:41:52PM +0100, Nuno Sá wrote:
> > > Document the ADIS16475 device devicetree bindings.
> > > 
> > > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > > ---
> > >  .../bindings/iio/imu/adi,adis16475.yaml       | 130
> > > ++++++++++++++++++
> > >  MAINTAINERS                                   |   1 +
> > >  2 files changed, 131 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/iio/imu/adi,adis16475.yaml
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/iio/imu/adi,adis16475.yaml
> > > b/Documentation/devicetree/bindings/iio/imu/adi,adis16475.yaml
> > > new file mode 100644
> > > index 000000000000..c0f2146e000c
> > > --- /dev/null
> > > +++
> > > b/Documentation/devicetree/bindings/iio/imu/adi,adis16475.yaml
> > > @@ -0,0 +1,130 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/iio/imu/adi,adis16475.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Analog Devices ADIS16475 and similar IMUs
> > > +
> > > +maintainers:
> > > +  - Nuno Sá <nuno.sa@analog.com>
> > > +
> > > +description: |
> > > +  Analog Devices ADIS16475 and similar IMUs
> > > +  
> > > https://www.analog.com/media/en/technical-documentation/data-sheets/ADIS16475.pdf
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - adi,adis16475-1
> > > +      - adi,adis16475-2
> > > +      - adi,adis16475-3
> > > +      - adi,adis16477-1
> > > +      - adi,adis16477-2
> > > +      - adi,adis16477-3
> > > +      - adi,adis16470
> > > +      - adi,adis16465-1
> > > +      - adi,adis16465-2
> > > +      - adi,adis16465-3
> > > +      - adi,adis16467-1
> > > +      - adi,adis16467-2
> > > +      - adi,adis16467-3
> > > +      - adi,adis16500
> > > +      - adi,adis16505-1
> > > +      - adi,adis16505-2
> > > +      - adi,adis16505-3
> > > +      - adi,adis16507-1
> > > +      - adi,adis16507-2
> > > +      - adi,adis16507-3
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  spi-cpha: true
> > > +
> > > +  spi-cpol: true
> > > +
> > > +  spi-max-frequency:
> > > +    maximum: 2000000
> > > +
> > > +  interrupts:
> > > +    maxItems: 1
> > > +
> > > +  clocks:
> > > +    maxItems: 1
> > > +
> > > +  clock-names:
> > > +    oneOf:
> > > +      - const: sync
> > > +      - const: direct-sync
> > > +      - const: pulse-sync
> > > +      - const: scaled-sync
> > 
> > According to the datasheet I looked at, the input is called 'sync'.
> > It 
> > looks like you are mixing operating mode and clock connection.
> 
> The sync pin is where the external clock should be connected (when
> available). I'm kinda of using the clock-name property as a way of
> selecting the mode the user wants to use as done in other devices (
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/iio/imu/adi,adis16480.txt
> ). In the end, what we should have in the sync pin is an external
> clock
> with the exception of the `sync` mode. I guess this one could be
> called
> output-sync and, in this case, the sync pin is actually an output pin
> pulsing when the internal processor collects data.
> 
> I'm ok in changing it if there's a better way of doing it... Do you
> have any suggestion?
> 
> -Nuno Sá

So, you mean having the clock-name only as "sync" (or maybe even
removing it?) and having a dedicated property like clock-mode?

-Nuno Sá
> > > +
> > > +  reset-gpios:
> > > +    description:
> > > +      Must be the device tree identifier of the RESET pin. If
> > > specified,
> > > +      it will be asserted during driver probe. As the line is
> > > active low,
> > > +      it should be marked GPIO_ACTIVE_LOW.
> > > +    maxItems: 1
> > > +
> > > +  adi,scaled-output-hz:
> > > +    description:
> > > +      This property must be present if the clock mode is scaled-
> > > sync through
> > > +      clock-names property. In this mode, the input clock can
> > > have
> > > a range
> > > +      of 1Hz to 128HZ which must be scaled to originate an
> > > allowable sample
> > > +      rate. This property specifies that rate.
> > > +    minimum: 1900
> > > +    maximum: 2100
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - interrupts
> > > +  - spi-cpha
> > > +  - spi-cpol
> > > +
> > > +if:
> > > +  properties:
> > > +    compatible:
> > > +      contains:
> > > +        enum:
> > > +          - adi,adis16500
> > > +          - adi,adis16505-1
> > > +          - adi,adis16505-2
> > > +          - adi,adis16505-3
> > > +          - adi,adis16507-1
> > > +          - adi,adis16507-2
> > > +          - adi,adis16507-3
> > > +
> > > +then:
> > > +  properties:
> > > +    clock-names:
> > > +      oneOf:
> > > +        - const: sync
> > > +        - const: direct-sync
> > > +        - const: scaled-sync
> > > +
> > > +    adi,burst32-enable:
> > > +      description:
> > > +        Enable burst32 mode. In this mode, a burst reading
> > > contains calibrated
> > > +        gyroscope and accelerometer data in 32-bit format.
> > > +      type: boolean
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/interrupt-controller/irq.h>
> > > +    spi {
> > > +            #address-cells = <1>;
> > > +            #size-cells = <0>;
> > > +
> > > +            adis16475: adis16475-3@0 {
> > > +                    compatible = "adi,adis16475-3";
> > > +                    reg = <0>;
> > > +                    spi-cpha;
> > > +                    spi-cpol;
> > > +                    spi-max-frequency = <2000000>;
> > > +                    interrupts = <4 IRQ_TYPE_EDGE_RISING>;
> > > +                    interrupt-parent = <&gpio>;
> > > +            };
> > > +    };
> > > +...
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index f11262f1f3bb..f8ccc92ab378 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -1015,6 +1015,7 @@ W:	
> > > http://ez.analog.com/community/linux-device-drivers
> > >  S:	Supported
> > >  F:	drivers/iio/imu/adis16475.c
> > >  F:	Documentation/ABI/testing/sysfs-bus-iio-imu-adis16475
> > > +F:	Documentation/devicetree/bindings/iio/imu/adi,adis16475
> > > .yaml
> > >  
> > >  ANALOG DEVICES INC ADM1177 DRIVER
> > >  M:	Beniamin Bia <beniamin.bia@analog.com>
> > > -- 
> > > 2.25.1