On Thu, Apr 13, 2017 at 03:01:40PM -0500, Rob Herring wrote:
> On Fri, Apr 07, 2017 at 03:00:09PM -0700, Moritz Fischer wrote:
> > From: Moritz Fischer <m...@kernel.org>
> >
> > Add bindings for the Chromium EC HWMON. The Chromium EC HWMON
> > allows monitoring of temperature sensors and fans attached to the
> > EC.
> >
> > Signed-off-by: Moritz Fischer <m...@kernel.org>
> > ---
> > .../devicetree/bindings/hwmon/cros-ec-hwmon.txt | 25
> > ++++++++++++++++++++++
> > 1 file changed, 25 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/hwmon/cros-ec-hwmon.txt
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/cros-ec-hwmon.txt
> > b/Documentation/devicetree/bindings/hwmon/cros-ec-hwmon.txt
> > new file mode 100644
> > index 0000000..4c94869
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/cros-ec-hwmon.txt
> > @@ -0,0 +1,25 @@
> > +Chromium Embedded Controller EC temperature and fan control
> > +-----------------------------------------------------------
> > +
> > +Google's Chromium EC HWMON is a hwmon implemented byimplemented by the
> > Chromium EC
> > +firmware attached to the Embedded Controller (EC) and controlled via a
> > host-command
> > +interface.
> > +
> > +An EC HWMON node should be only found as a sub-node of the EC node (see
> > +Documentation/devicetree/bindings/mfd/cros-ec.txt).
> > +
> > +Required properties:
> > +- compatible: Must contain "google,cros-ec-hwmon"
> > +
> > +Example:
> > + embedded-controller@1e {
> > + reg = <0x1e>;
> > + compatible = "google,cros-ec-i2c";
> > + interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
> > + interrupt-parent = <&gpio0>;
> > +
> > + hwmon {
> > + compatible = "google,cros-ec-hwmon";
>
> This is sufficient for all devices? I don't see that DT provides
> anything here other than instantiating a device, but the parent device
> can just as easily do that.
>
The parent driver (drivers/mfd/cros_ec_i2c.c) calls cros_ec_register(),
which uses uses of_platform_populate() to populate all sub-devices.
There are various examples in the dts files (look for "google,cros-ec").
Does it really make sense to start a second method for instantiating
sub-devices ?
Thanks,
Guenter
