| Message ID | 20181203101547.16835-5-jagan@amarulasolutions.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/9] dt-bindings: gpio-axp209: Add AXP803 GPIOs compatible (w/ AXP813 fallback) | expand |
On Mon, Dec 3, 2018 at 6:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote: > > vcc-supply property is need for some Goodix CTP controller like GT5663 > where 3.3V external pull-up regulator connected via controller VCC pin. "External pull-up regulator" sounds fishy. Chips have power supply pins, either combined, or separate rails for analog, digital, and I/O. For Goodix chips these are AVDD28, AVDD22, DVDD12, amd VDDIO. The name and description you provide match none of these. If a regulator is needed for pull-up resistors on the I2C bus, this should be referenced in either the I2C bus master node, or if the I2C bus goes through a pin controller, in the pin controller node. Putting the reference in the slave device node is wrong, since it doesn't actually use it. It becomes even clearer when you have multiple slaves on the same bus, and you reference the same regulator in all of them. Or, as a last resort, you could mark it as always-on with a TODO note. ChenYu > So, document the same as optional property. > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> > --- > Documentation/devicetree/bindings/input/touchscreen/goodix.txt | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > index f7e95c52f3c7..604766e347ce 100644 > --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt > @@ -23,6 +23,7 @@ Optional properties: > - touchscreen-inverted-y : Y axis is inverted (boolean) > - touchscreen-swapped-x-y : X and Y axis are swapped (boolean) > (swapping is done after inverting the axis) > + - vcc-supply : 3v3 regulator phandle for controller VCC pin > > Example: > > -- > 2.18.0.321.gffc6fa0e3 >
On Mon, Dec 3, 2018 at 4:11 PM Chen-Yu Tsai <wens@csie.org> wrote: > > On Mon, Dec 3, 2018 at 6:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote: > > > > vcc-supply property is need for some Goodix CTP controller like GT5663 > > where 3.3V external pull-up regulator connected via controller VCC pin. > > "External pull-up regulator" sounds fishy. Chips have power supply > pins, either combined, or separate rails for analog, digital, and I/O. > For Goodix chips these are AVDD28, AVDD22, DVDD12, amd VDDIO. The name > and description you provide match none of these. We have vcc pin in the connector to supply vcc-ctp, but indeed it is AVDD28 supply as per the reference schematic design[1] Page 23. Host interface has AVDD pin which is connected to ADVDD28 on goodix chip, so I can name this as avdd28-supply. is that OK? [1] https://www.crystalfontz.com/controllers/GOODIX/GT5663/459/
On Thu, Dec 6, 2018 at 3:56 AM Jagan Teki <jagan@amarulasolutions.com> wrote: > > On Mon, Dec 3, 2018 at 4:11 PM Chen-Yu Tsai <wens@csie.org> wrote: > > > > On Mon, Dec 3, 2018 at 6:16 PM Jagan Teki <jagan@amarulasolutions.com> wrote: > > > > > > vcc-supply property is need for some Goodix CTP controller like GT5663 > > > where 3.3V external pull-up regulator connected via controller VCC pin. > > > > "External pull-up regulator" sounds fishy. Chips have power supply > > pins, either combined, or separate rails for analog, digital, and I/O. > > For Goodix chips these are AVDD28, AVDD22, DVDD12, amd VDDIO. The name > > and description you provide match none of these. > > We have vcc pin in the connector to supply vcc-ctp, but indeed it is > AVDD28 supply as per the reference schematic design[1] Page 23. Host > interface has AVDD pin which is connected to ADVDD28 on goodix chip, > so I can name this as avdd28-supply. is that OK? Yeah. That's better. It's always best to be precise with hardware descriptions. If you simplify it, the reason should be given in detail. And it should be a good one. ChenYu
diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt index f7e95c52f3c7..604766e347ce 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.txt +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.txt @@ -23,6 +23,7 @@ Optional properties: - touchscreen-inverted-y : Y axis is inverted (boolean) - touchscreen-swapped-x-y : X and Y axis are swapped (boolean) (swapping is done after inverting the axis) + - vcc-supply : 3v3 regulator phandle for controller VCC pin Example:
vcc-supply property is need for some Goodix CTP controller like GT5663 where 3.3V external pull-up regulator connected via controller VCC pin. So, document the same as optional property. Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> --- Documentation/devicetree/bindings/input/touchscreen/goodix.txt | 1 + 1 file changed, 1 insertion(+)