| Message ID | 4ca1795c6e09eb89f481cdec55180b4f1165bbfd.1514898134.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Baruch, > Baruch Siach <baruch@tkos.co.il> hat am 2. Januar 2018 um 14:19 geschrieben: > > > The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware over > I2C. The firmware mailbox interface allows the ARM core to control the > GPIO lines. > > Signed-off-by: Baruch Siach <baruch@tkos.co.il> > --- > .../bindings/gpio/brcm,bcm2835-expgpio.txt | 24 ++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > create mode 100644 Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt > > diff --git a/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt > new file mode 100644 > index 000000000000..55257f31a9be > --- /dev/null > +++ b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt > @@ -0,0 +1,24 @@ > +Raspberry Pi GPIO expander > + > +The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The > +firmware exposes a mailbox interface that allows the ARM core to control the > +GPIO lines on the expander. > + > +Required properties: > + > +- compatible : Should be "brcm,bcm2835-expgpio" from my understand this driver is specific to the Raspberry Pi and it's vendor is the Raspberry Pi Foundation. So i prefer Eric's suggestion of "raspberrypi,firmware-gpio", which also applies to the filename. > +- gpio-controller : Marks the device node as a gpio controller > +- #gpio-cells : Should be two. The first cell is the pin number, and > + the second cell is used to specify the gpio polarity: > + 0 = active high > + 1 = active low > +- firmware : Reference to the RPi firmware device node > + > +Example: > + > +expgpio: expgpio { > + compatible = "brcm,bcm2835-expgpio"; > + gpio-controller; > + #gpio-cells = <2>; > + firmware = <&firmware>; > +}; > -- > 2.15.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Hi Stefan, On Tue, Jan 02, 2018 at 07:26:00PM +0100, Stefan Wahren wrote: > > Baruch Siach <baruch@tkos.co.il> hat am 2. Januar 2018 um 14:19 geschrieben: > > > > > > The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware over > > I2C. The firmware mailbox interface allows the ARM core to control the > > GPIO lines. > > > > Signed-off-by: Baruch Siach <baruch@tkos.co.il> > > --- > > .../bindings/gpio/brcm,bcm2835-expgpio.txt | 24 ++++++++++++++++++++++ > > 1 file changed, 24 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt > > > > diff --git a/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt > > new file mode 100644 > > index 000000000000..55257f31a9be > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt > > @@ -0,0 +1,24 @@ > > +Raspberry Pi GPIO expander > > + > > +The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The > > +firmware exposes a mailbox interface that allows the ARM core to control the > > +GPIO lines on the expander. > > + > > +Required properties: > > + > > +- compatible : Should be "brcm,bcm2835-expgpio" > > from my understand this driver is specific to the Raspberry Pi and it's > vendor is the Raspberry Pi Foundation. So i prefer Eric's suggestion of > "raspberrypi,firmware-gpio", which also applies to the filename. That was my inclination as well. But I thought that keeping DT compatibility with downstream is desirable. I'll change compatible/file/driver names to raspberry something. baruch > > +- gpio-controller : Marks the device node as a gpio controller > > +- #gpio-cells : Should be two. The first cell is the pin number, and > > + the second cell is used to specify the gpio polarity: > > + 0 = active high > > + 1 = active low > > +- firmware : Reference to the RPi firmware device node > > + > > +Example: > > + > > +expgpio: expgpio { > > + compatible = "brcm,bcm2835-expgpio"; > > + gpio-controller; > > + #gpio-cells = <2>; > > + firmware = <&firmware>; > > +};
diff --git a/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt new file mode 100644 index 000000000000..55257f31a9be --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt @@ -0,0 +1,24 @@ +Raspberry Pi GPIO expander + +The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The +firmware exposes a mailbox interface that allows the ARM core to control the +GPIO lines on the expander. + +Required properties: + +- compatible : Should be "brcm,bcm2835-expgpio" +- gpio-controller : Marks the device node as a gpio controller +- #gpio-cells : Should be two. The first cell is the pin number, and + the second cell is used to specify the gpio polarity: + 0 = active high + 1 = active low +- firmware : Reference to the RPi firmware device node + +Example: + +expgpio: expgpio { + compatible = "brcm,bcm2835-expgpio"; + gpio-controller; + #gpio-cells = <2>; + firmware = <&firmware>; +};
The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware over I2C. The firmware mailbox interface allows the ARM core to control the GPIO lines. Signed-off-by: Baruch Siach <baruch@tkos.co.il> --- .../bindings/gpio/brcm,bcm2835-expgpio.txt | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt