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| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt b/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt new file mode 100644 index 000000000..e90fb987e --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt @@ -0,0 +1,64 @@ +APM X-Gene Standby GPIO controller bindings + +This is a gpio controller in the standby domain. It also supports interrupt in +some particular pins which are sourced to its parent interrupt controller +as diagram below: + +-----------------+ + | X-Gene standby | + | GPIO controller +------ GPIO_0 ++------------+ | | ... +| Parent IRQ | EXT_INT_0 | +------ GPIO_8/EXT_INT_0 +| controller | (SPI40) | | ... +| (GICv2) +--------------+ +------ GPIO_[N+8]/EXT_INT_N +| | ... | | +| | EXT_INT_N | +------ GPIO_[N+9] +| | (SPI[40 + N])| | ... +| +--------------+ +------ GPIO_MAX ++------------+ +-----------------+ + +Required properties: +- compatible: "apm,xgene-gpio-sb" for the X-Gene Standby GPIO controller +- reg: Physical base address and size of the controller's registers +- #gpio-cells: Should be two. + - first cell is the pin number + - second cell is used to specify the gpio polarity: + 0 = active high + 1 = active low +- gpio-controller: Marks the device node as a GPIO controller. +- interrupts: The EXT_INT_0 parent interrupt resource must be listed first. +- interrupt-cells: Should be two. + - first cell is 0-N coresponding for EXT_INT_0 to EXT_INT_N. + - second cell is used to specify flags. +- interrupt-controller: Marks the device node as an interrupt controller. +- apm,nr-gpios: Optional, specify number of gpios pin. +- apm,nr-irqs: Optional, specify number of interrupt pins. +- apm,irq-start: Optional, specify lowest gpio pin support interrupt. + +Example: + sbgpio: gpio@17001000{ + compatible = "apm,xgene-gpio-sb"; + reg = <0x0 0x17001000 0x0 0x400>; + #gpio-cells = <2>; + gpio-controller; + interrupts = <0x0 0x28 0x1>, + <0x0 0x29 0x1>, + <0x0 0x2a 0x1>, + <0x0 0x2b 0x1>, + <0x0 0x2c 0x1>, + <0x0 0x2d 0x1>; + interrupt-parent = <&gic>; + #interrupt-cells = <2>; + interrupt-controller; + apm,nr-gpios = <22>; + apm,nr-irqs = <6>; + apm,irq-start = <8>; + }; + + testuser { + compatible = "example,testuser"; + /* Use the GPIO_13/EXT_INT_5 line as an active high triggered + * level interrupt + */ + interrupts = <5 4>; + interrupt-parent = <&sbgpio>; + }; |