On November 6, 2017 1:06:30 AM PST, Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> wrote: >Hi Rob, > >On Nov 01 2017 or thereabouts, Rob Herring wrote: >> On Tue, Oct 31, 2017 at 11:03:16AM +0800, Lin Huang wrote: >> > Document a "reset" and "assert-reset-us", it can be used for >> > driver control reset property. And reuse post-power-on-delay-ms >> > for deassert reset delay. >> >> "dt-bindings: input: " for the subject please. >> >> > >> > Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx> >> > --- >> > Documentation/devicetree/bindings/input/hid-over-i2c.txt | 4 +++- >> > 1 file changed, 3 insertions(+), 1 deletion(-) >> > >> > diff --git >a/Documentation/devicetree/bindings/input/hid-over-i2c.txt >b/Documentation/devicetree/bindings/input/hid-over-i2c.txt >> > index 28e8bd8..6ab0eed 100644 >> > --- a/Documentation/devicetree/bindings/input/hid-over-i2c.txt >> > +++ b/Documentation/devicetree/bindings/input/hid-over-i2c.txt >> > @@ -31,7 +31,9 @@ device-specific compatible properties, which >should be used in addition to the >> > >> > - vdd-supply: phandle of the regulator that provides the supply >voltage. >> > - post-power-on-delay-ms: time required by the device after >enabling its regulators >> > - before it is ready for communication. Must be used with >'vdd-supply'. >> > + or deassert reset pin before it is ready for communication. >> > +- reset: phandle of the gpio that provides for hid reset pin. >> >> The kernel api takes "reset", but the property is "reset-gpios". > >In the same way the generic regulator interface handles vdd-supply, is >there any generic OF handling of reset lines? As far as I can tell, >there are 97 references of reset-gpios in my tree, and I wonder if all >the matching drivers need to rewrite the same code to set the reset >line >on power on/off. > >I am worried because here, 1/2 writes "arbitrary" 0 and 1 to the gpios, >and nothing prevent a manufacturer to invert the required voltages on >the reset lines, meaning there will be a need for a new OF property. 1and 0 are logical high and low here. Gpiod API takes care of converting to the proper polarity. Thanks. -- Dmitry -- 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
