Re: [PATCH v3 3/3] mfd: wm831x: Add device tree binding document

From: Charles Keepax
Date: Wed Mar 15 2017 - 11:24:55 EST


On Tue, Mar 14, 2017 at 02:59:35PM +0000, Lee Jones wrote:
> On Mon, 06 Mar 2017, Charles Keepax wrote:
>
> > Add a device tree binding document for the wm831x series of PMICs.
> > Currently only support for the registering the device and the GPIOs are
> > actually implemented in the driver.
> >
> > Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> > ---
> >
> > Changes since v2:
> > - Flesh the binding some more with some additional features of the device,
> > although these are not yet implemented in the code.
> >
> > Documentation/devicetree/bindings/mfd/wm831x.txt | 81 ++++++++++++++++++++++++
> > MAINTAINERS | 1 +
> > 2 files changed, 82 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/mfd/wm831x.txt
> >
> > diff --git a/Documentation/devicetree/bindings/mfd/wm831x.txt b/Documentation/devicetree/bindings/mfd/wm831x.txt
> > new file mode 100644
> > index 0000000..680ac18
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mfd/wm831x.txt
> > @@ -0,0 +1,81 @@
> > +Cirrus Logic/Wolfson Microelectronics wm831x PMICs
> > +
> > +System PMICs with a wide range of additional features.
> > +
> > +Required properties:
> > +
> > + - compatible : One of the following chip-specific strings:
> > + "wlf,wm8310"
> > + "wlf,wm8311"
> > + "wlf,wm8312"
> > + "wlf,wm8320"
> > + "wlf,wm8321"
> > + "wlf,wm8325"
> > + "wlf,wm8326"
> > +
> > + - reg : I2C slave address when connected using I2C, chip select number
> > + when using SPI.
> > +
> > + - gpio-controller : Indicates this device is a GPIO controller.
> > + - #gpio-cells : Must be 2. The first cell is the pin number and the
> > + second cell is used to specify optional parameters (currently unused).
>
> Then why not "must be 1", if the second cell is unused?
>

I believe it is generally advised to use at least 2 cells for
GPIOs and since there is a reasonable chance someone might add
flags later seems better have it in the binding already.

> > + - interrupts : The interrupt line the /IRQ signal for the device is
> > + connected to.
>
> What's with the '/'?

Active low, but will remove.

>
> > + - interrupt-parent : The parent interrupt controller.
> > +
> > + - interrupt-controller : wm831x devices contain interrupt controllers and
> > + may provide interrupt services to other devices.
> > + - #interrupt-cells: Must be 2. The first cell is the IRQ number, and the
> > + second cell is the flags, encoded as the trigger masks from
> > + Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
>
> Please use the succinct "../../" format.

Can do.

Thanks,
Charles