> Stephen Warren <swar...@wwwdotorg.org> hat am 26. September 2016 um 18:38 > geschrieben: > > > On 09/23/2016 12:39 PM, Stefan Wahren wrote: > > Hi Eric, > > > >> Eric Anholt <e...@anholt.net> hat am 19. September 2016 um 18:13 > >> geschrieben: > >> > >> > >> The RPi firmware exposes all of the board's GPIO lines through > >> property calls. Linux chooses to control most lines directly through > >> the pinctrl driver, but for the FXL6408 GPIO expander on the Pi3, we > >> need to access them through the firmware. > >> > >> Signed-off-by: Eric Anholt <e...@anholt.net> > >> --- > >> .../bindings/gpio/gpio-raspberrypi-firmware.txt | 22 > >> ++++++++++++++++++++++ > >> 1 file changed, 22 insertions(+) > >> create mode 100644 > >> Documentation/devicetree/bindings/gpio/gpio-raspberrypi-firmware.txt > >> > >> diff --git > >> a/Documentation/devicetree/bindings/gpio/gpio-raspberrypi-firmware.txt > >> b/Documentation/devicetree/bindings/gpio/gpio-raspberrypi-firmware.txt > >> new file mode 100644 > >> index 000000000000..2b635c23a6f8 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/gpio/gpio-raspberrypi-firmware.txt > >> @@ -0,0 +1,22 @@ > >> +Raspberry Pi power domain driver > >> + > >> +Required properties: > >> + > >> +- compatible: Should be "raspberrypi,firmware-gpio" > > > > i think the compatible should be more specific like > > > > raspberrypi,rpi3-firmware-gpio > > > > and all information which aren't requestable from the firmware should be > > stored > > in a info structure. This makes the driver easier to extend in the future by > > adding new compatibles and their info structures. > > Is this actually specific to the Pi3 at all?
AFAIK only the Raspberry Pi 3 has a GPIO expander which is accessible via the common FW. My suggestion tries to follow the basic guideline "A precise compatible string is better than a vague one" from Device Tree for Dummies [1]. So in case the next Raspberry Pi would have a different GPIO expander with different parameters we could add a new compatible. But you are right the word order in "rpi3-firmware-gpio" suggests that there are different FW which is wrong. At the end it's only a compatible string. So no strong opinion about the naming. [1] - https://events.linuxfoundation.org/sites/events/files/slides/petazzoni-device-tree-dummies.pdf > Isn't the FW the same > across all Pis; the part that's specific to the Pi3 is whether it's > useful to use that API? > > As such, I'd suggest just raspberrypi,firmware-gpio as the compatible value. >
