On Thu, Jun 13, 2019 at 04:39:45PM -0600, Rob Herring wrote: > On Fri, May 17, 2019 at 03:12:50PM +0200, Michal Vokáč wrote: > > Normally, the MPR121 controller uses separate interrupt line to notify > > the I2C host that a key was touched/released. To support platforms that > > can not use the interrupt line, polling of the MPR121 registers can be > > used. > > 'separate' from what? > > > > > Signed-off-by: Michal Vokáč <michal.vokac@xxxxxxxxx> > > --- > > Changes since v1: > > - Document the polled binding in the original file, do not create a new one. > > (Rob) > > > > Documentation/devicetree/bindings/input/mpr121-touchkey.txt | 9 +++++++-- > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/input/mpr121-touchkey.txt b/Documentation/devicetree/bindings/input/mpr121-touchkey.txt > > index b7c61ee5841b..97f55273d473 100644 > > --- a/Documentation/devicetree/bindings/input/mpr121-touchkey.txt > > +++ b/Documentation/devicetree/bindings/input/mpr121-touchkey.txt > > @@ -1,9 +1,14 @@ > > -* Freescale MPR121 Controllor > > +* Freescale MPR121 Controller > > > > Required Properties: > > -- compatible: Should be "fsl,mpr121-touchkey" > > +- compatible: Should be one of: > > + - "fsl,mpr121-touchkey" - MPR121 with interrupt line > > + - "fsl,mpr121-touchkey-polled" - MPR121 with polling > > - reg: The I2C slave address of the device. > > - interrupts: The interrupt number to the cpu. > > + In case of "fsl,mpr121-touchkey-polled" the interrupt > > + line is not used and hence the interrupts property is > > + not required. > > Absence of the interrupts property is enough to determine polled mode > and you don't need a separate compatible string. I would prefer if we could distinguish between chip working in polled mode intentionally vs DT writer simply forgetting to specify interrupt property. Should we key the polling mode off "linux,poll-interval" property? We probably going to need it anyway as not everyone needs the same polling frequency. Thanks. -- Dmitry
