On Wed, Mar 28, 2018 at 01:53:53PM -0700, Tim Harvey wrote: > On Wed, Mar 28, 2018 at 1:23 PM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > On Wed, Mar 28, 2018 at 12:17:34PM -0700, Tim Harvey wrote: > >> On Wed, Mar 28, 2018 at 9:24 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > >> > On Wed, Mar 28, 2018 at 08:14:00AM -0700, Tim Harvey wrote: > >> >> This patch adds documentation of device-tree bindings for the > >> >> Gateworks System Controller (GSC). > >> >> > >> >> Signed-off-by: Tim Harvey <tharvey@xxxxxxxxxxxxx> > >> >> --- > >> >> v3: > >> >> - replaced _ with - > >> >> - remove input bindings > >> >> - added full description of hwmon > >> >> - fix unit address of hwmon child nodes > >> >> > >> >> --- > >> >> .../devicetree/bindings/mfd/gateworks-gsc.txt | 135 +++++++++++++++++++++ > >> >> 1 file changed, 135 insertions(+) > >> >> create mode 100644 Documentation/devicetree/bindings/mfd/gateworks-gsc.txt > >> >> > >> >> diff --git a/Documentation/devicetree/bindings/mfd/gateworks-gsc.txt b/Documentation/devicetree/bindings/mfd/gateworks-gsc.txt > >> >> new file mode 100644 > >> >> index 0000000..8f530ed > >> >> --- /dev/null > >> >> +++ b/Documentation/devicetree/bindings/mfd/gateworks-gsc.txt > >> >> @@ -0,0 +1,135 @@ > >> >> +Gateworks System Controller multi-function device > >> >> + > >> >> +The GSC is a Multifunction I2C slave device with the following submodules: > >> >> +- WDT > >> >> +- GPIO > >> >> +- Pushbutton controller > >> >> +- HWMON > >> >> + > >> >> +Required properties: > >> >> +- compatible : Must be "gw,gsc" > >> >> +- reg: I2C address of the device > >> >> +- interrupts: interrupt triggered by GSC_IRQ# signal > >> >> +- interrupt-parent: Interrupt controller GSC is connected to > >> >> +- #interrupt-cells: should be <1>, index of the interrupt within the > >> >> + controller, in accordance with the "one cell" variant of > >> >> + <devicetree/bindings/interrupt-controller/interrupt.txt> > >> >> + > >> >> +Optional nodes: > >> >> +* watchdog: > >> >> +The GSC provides a Watchdog monitor which can power cycle the board's > >> >> +primary power supply on most board models when tripped. > >> >> + > >> >> +Required watchdog properties: > >> >> +- compatible: must be "gw,gsc-watchdog" > >> >> + > >> >> +* hwmon: > >> >> +The GSC provides a set of Analog to Digitcal Converter (ADC) pins used for > >> >> +temperature and/or voltage monitoring. > >> >> + > >> >> +Required hwmon properties: > >> >> +- compatible: must be "gw,gsc-hwmon" > >> >> + > >> > > >> > "hwmon" is a very Linux specific term. It might make sense to find a more > >> > generic term. > >> > >> The 'hwmon' driver supports child nodes that fall into the following category: > >> - temperature sensor (GSC internal temperature sensor - i2c registers > >> returns value in C*10) > >> - voltage rails (two types here; cooked: i2c registers return > >> pre-scaled value in mV), raw: i2c registers return a raw ADC value > >> that must be scaled based on ADC internal ref voltage and resolution > >> and adjusted for a voltage divider to convert to mV > >> - fan setpoints (I'll explain these below) > >> > >> I called the node 'gw,gsc-hwmon' because the driver fits into the > >> 'hwmon' API. Isn't that appropriate here for the driver compatible > >> string? > >> > > > > Devicetree properties are supposed to be OS independent. +1 > > > >> > > >> >> +Optional hwmon properties: > >> >> +- gw,reference-voltage: ADC reference voltage (mV) used in scaling raw ADCs > >> > > >> > AFAIK devicetree likes to specify voltages in uV. > >> > >> There are currently plenty of dt props specified in mV (grep -r mV > >> Documentation/devicetree/bindings/). > >> > > > > "But so many others are speeding, why do I get a ticket ?" > > > > Please discuss with Rob. > > Yes - hoping for feedback on mV vs uV as well as naming of hwmon mfd child node. Use what is defined in Documentation/devicetree/bindings/property-units.txt. If you don't like what is there, then add to it first. But generally you should have some reason why what's there doesn't work for you. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
