Re: [PATCH 1/3] dt-bindings: Add a binding for the RPi firmware GPIO driver.

From: Stephen Warren
Date: Mon Sep 26 2016 - 12:38:59 EST


On 09/23/2016 12:39 PM, Stefan Wahren wrote:
Hi Eric,

Eric Anholt <eric@xxxxxxxxxx> 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 <eric@xxxxxxxxxx>
---
.../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? 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.