Re: [PATCH 2/2] dt-bindings: document gpio-mt7621 bindings
From: Rob Herring <robh@kernel.org>
Date: 2018-06-12 20:56:38
Also in:
linux-gpio
On Sat, Jun 02, 2018 at 09:30:10AM +0200, Sergio Paracuellos wrote:
Add a devicetree binding documentation for the mt7621 driver.
Bindings are for h/w, not a driver.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> Reviewed-by: NeilBrown <neil@brown.name>
Space ^
quoted hunk ↗ jump to hunk
--- .../bindings/gpio/mediatek,mt7621-gpio.txt | 68 ++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/mediatek,mt7621-gpio.txtdiff --git a/Documentation/devicetree/bindings/gpio/mediatek,mt7621-gpio.txt b/Documentation/devicetree/bindings/gpio/mediatek,mt7621-gpio.txt new file mode 100644 index 0000000..30d8a02 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/mediatek,mt7621-gpio.txt@@ -0,0 +1,68 @@ +Mediatek SoC GPIO controller bindings + +The IP core used inside these SoCs has 3 banks of 32 GPIOs each. +The registers of all the banks are interwoven inside one single IO range. +We load one GPIO controller instance per bank. To make this possible +we support 2 types of nodes. The parent node defines the memory I/O range and +has 3 children each describing a single bank. Also the GPIO controller can receive +interrupts on any of the GPIOs, either edge or level. It then interrupts the CPU +using GIC INT12. + +Required properties for the top level node: +- compatible: + - "mediatek,mt7621-gpio" for Mediatek controllers +- reg : Physical base address and length of the controller's registers +- interrupt-parent : phandle of the parent interrupt controller. +- interrupts : Interrupt specifier for the controllers interrupt. +- interrupt-controller : Mark the device node as an interrupt controller. +- #interrupt-cells : Should be 2. The first cell defines the interrupt number. + The second cell bits[3:0] is used to specify trigger type as follows: + - 1 = low-to-high edge triggered. + - 2 = high-to-low edge triggered. + - 4 = active high level-sensitive. + - 8 = active low level-sensitive.
Just refer to the common definition.
+ + +Required properties for the GPIO bank node: +- compatible: + - "mediatek,mt7621-gpio-bank" for Mediatek banks +- #gpio-cells : Should be two. The first cell is the GPIO pin number and the
So interrupt numbers and gpio numbers are different? 0-95 and 3x 0-31 That doesn't seem ideal.
+ second cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. + Only the GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported. +- gpio-controller : Marks the device node as a GPIO controller. +- reg : The id of the bank that the node describes.
I'd prefer to not have banks defined in DT. Do you have a variable number or resources that are per bank? If not, then you don't need them.
+
+Example:
+ gpio@600 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ compatible = "mediatek,mt7621-gpio";
+ reg = <0x600 0x100>;
+
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SHARED 12 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ gpio0: bank@0 {
+ reg = <0>;
+ compatible = "mediatek,mt7621-gpio-bank";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+
+ gpio1: bank@1 {
+ reg = <1>;
+ compatible = "mediatek,mt7621-gpio-bank";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+
+ gpio2: bank@2 {
+ reg = <2>;
+ compatible = "mediatek,mt7621-gpio-bank";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+ };
--
2.7.4