| Message ID | 214ff3856c430b8045b63b25d83733b77054dfab.1517923836.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Feb 07, 2018 at 08:35:23PM +0200, Baruch Siach wrote: > 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> > --- > v4: > * Move the example gpio node under the firmware node > * Rename gpio node name to plain 'gpio' > > v3: > * Rename node name. > > v2: > * Rename compatible string to raspberrypi,firmware-gpio > --- > .../bindings/gpio/raspberrypi,firmware-gpio.txt | 29 ++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > create mode 100644 Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt > > diff --git a/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt > new file mode 100644 > index 000000000000..30326528faa9 > --- /dev/null > +++ b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt > @@ -0,0 +1,29 @@ > +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 "raspberrypi,firmware-gpio" > +- 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 This is the parent node. You don't need it. > + > +Example: > + > +firmware: firmware { > + compatible = "raspberrypi,bcm2835-firmware"; > + mboxes = <&mailbox>; No, sorry. /firmware is the container of firmware nodes. So something like this: firmware { rpi-firmware { compatible = "raspberrypi,bcm2835-firmware"; mboxes = <&mailbox>; gpio { compatible = "raspberrypi,firmware-gpio"; }; }; }; > + > + expgpio: gpio { > + compatible = "raspberrypi,firmware-gpio"; > + gpio-controller; > + #gpio-cells = <2>; > + firmware = <&firmware>; > + }; > +}; > -- > 2.15.1 >
Hi Rob, Thanks again for reviewing. On Tue, Feb 13, 2018 at 05:20:07PM -0600, Rob Herring wrote: > On Wed, Feb 07, 2018 at 08:35:23PM +0200, Baruch Siach wrote: > > +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 "raspberrypi,firmware-gpio" > > +- 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 > > This is the parent node. You don't need it. OK. I guess of_get_parent() will do the trick. > > +Example: > > + > > +firmware: firmware { > > + compatible = "raspberrypi,bcm2835-firmware"; > > + mboxes = <&mailbox>; > > No, sorry. /firmware is the container of firmware nodes. So > something like this: > > firmware { > rpi-firmware { > compatible = "raspberrypi,bcm2835-firmware"; > mboxes = <&mailbox>; > gpio { > compatible = "raspberrypi,firmware-gpio"; > > }; > }; > }; This is the hierarchy we currently have at arch/arm/boot/dts/bcm2835-rpi.dtsi: / { soc { firmware: firmware { compatible = "raspberrypi,bcm2835-firmware"; mboxes = <&mailbox>; }; }; }; Are you suggesting to add another container between 'soc' and 'firmware'? Or is it the 'firmware' node name that we need to change to 'rpi-firmware'? > > + > > + expgpio: gpio { > > + compatible = "raspberrypi,firmware-gpio"; > > + gpio-controller; > > + #gpio-cells = <2>; > > + firmware = <&firmware>; > > + }; > > +}; baruch
On Tue, Feb 20, 2018 at 1:34 AM, Baruch Siach <baruch@tkos.co.il> wrote: > Hi Rob, > > Thanks again for reviewing. > > On Tue, Feb 13, 2018 at 05:20:07PM -0600, Rob Herring wrote: >> On Wed, Feb 07, 2018 at 08:35:23PM +0200, Baruch Siach wrote: >> > +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 "raspberrypi,firmware-gpio" >> > +- 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 >> >> This is the parent node. You don't need it. > > OK. I guess of_get_parent() will do the trick. > >> > +Example: >> > + >> > +firmware: firmware { >> > + compatible = "raspberrypi,bcm2835-firmware"; >> > + mboxes = <&mailbox>; >> >> No, sorry. /firmware is the container of firmware nodes. So >> something like this: >> >> firmware { >> rpi-firmware { >> compatible = "raspberrypi,bcm2835-firmware"; >> mboxes = <&mailbox>; >> gpio { >> compatible = "raspberrypi,firmware-gpio"; >> >> }; >> }; >> }; > > This is the hierarchy we currently have at arch/arm/boot/dts/bcm2835-rpi.dtsi: > > / { > soc { > firmware: firmware { > compatible = "raspberrypi,bcm2835-firmware"; > mboxes = <&mailbox>; > }; > }; > }; > > Are you suggesting to add another container between 'soc' and 'firmware'? Or > is it the 'firmware' node name that we need to change to 'rpi-firmware'? Ah, I guess RPi missed following putting its firmware node under a /firmware node rather than under /soc. We try to put all firmware interfaces (you can have more than one) under /firmware. So just as I wrote out. But you don't need to change that for this. Just noting this is a child of "raspberrypi,bcm2835-firmware" is enough. Rob
diff --git a/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt new file mode 100644 index 000000000000..30326528faa9 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt @@ -0,0 +1,29 @@ +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 "raspberrypi,firmware-gpio" +- 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: + +firmware: firmware { + compatible = "raspberrypi,bcm2835-firmware"; + mboxes = <&mailbox>; + + expgpio: gpio { + compatible = "raspberrypi,firmware-gpio"; + 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> --- v4: * Move the example gpio node under the firmware node * Rename gpio node name to plain 'gpio' v3: * Rename node name. v2: * Rename compatible string to raspberrypi,firmware-gpio --- .../bindings/gpio/raspberrypi,firmware-gpio.txt | 29 ++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/raspberrypi,firmware-gpio.txt