Messages in this thread | | | Subject | Re: [PATCH 1/3] pinctrl: Broadcom NSP GPIO-a device tree bindings | From | Ray Jui <> | Date | Wed, 2 Dec 2015 09:32:34 -0800 |
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Hi Rob,
On 12/2/2015 7:07 AM, Rob Herring wrote: > On Tue, Dec 01, 2015 at 11:46:38PM -0500, Yendapally Reddy Dhananjaya Reddy wrote: >> Device tree binding documentation for Broadcom NSP GPIO-a driver > > Bindings are for h/w, not drivers... > >> >> Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yrdreddy@broadcom.com> >> --- >> .../devicetree/bindings/pinctrl/brcm,nsp-gpio.txt | 80 ++++++++++++++++++++++ >> 1 file changed, 80 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt >> >> diff --git a/Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt b/Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt >> new file mode 100644 >> index 0000000..bea4211 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/pinctrl/brcm,nsp-gpio.txt >> @@ -0,0 +1,80 @@ >> +Broadcom Northstar plus (NSP) GPIO/PINCONF Controller >> + >> +Required properties: >> +- compatible: >> + Must be "brcm,nsp-gpio-a" >> + >> +- reg: >> + Should contain the register physical address and length for each of >> + GPIO base, IO control registers >> + >> +- #gpio-cells: >> + Must be two. The first cell is the GPIO pin number (within the >> + controller's pin space) and the second cell is used for the following: >> + bit[0]: polarity (0 for active high and 1 for active low) >> + >> +- gpio-controller: >> + Specifies that the node is a GPIO controller >> + >> +- ngpios: >> + Number of gpios supported (58x25 supports 32 and 58x23 supports 24) > > 2 chips? You should have 2 compatible strings. I think this is incorrect > use of ngpios which AIUI is not for how many lines there are, but how > many can be used (e.g. not reserved). >
I believe this is the identical GPIO controller IP that is integrated into two different SoC chip variants. The only difference is the supported number of GPIO pins.
In this case, I believe this is what Linus prefers: 1) Using a single compatible string (tied to the GPIO controller IP); 2) Addressing difference in number of GPIOs using DT property 'ngpios'.
Thanks,
Ray
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