我正在查看 Beagle Bone Black 的设备树并从 am57xx-beagle-x15.dts
开始.深入到 dra7.dtsi
我找到了 gpio1
:
gpio1: gpio@4ae10000 {
compatible = "ti,omap4-gpio";
reg = <0x4ae10000 0x200>;
interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
ti,hwmods = "gpio1";
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
};
我读过
#interrupt-cells
给出了 interrupts
中的一个项目所期望的 u32 或单元的数量。列表。但是当我看 interrupts
我看到一个三元组:<GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>
.很想知道,为什么这包含 3 个单元格而不是 2 个?
最佳答案
这是一个很晚的答案,但添加一个以便有人可以获得帮助。
我无法从当前的 linux 5.15 源中找到确切的 dts 文件。但是节点的中断父节点应该需要 3 个单元的中断属性。对于 gic,通常需要 3 个值 - {interrupt type, interrupt number, flag}。它在gic的设备绑定(bind)文档中(Linux 5.15中的Documentation/devicetree/bindings/interrupt-controller/arm,gic.yaml)
"#interrupt-cells":
const: 3
description: |
The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
interrupts.
The 2nd cell contains the interrupt number for the interrupt type.
SPI interrupts are in the range [0-987]. PPI interrupts are in the
range [0-15].
The 3rd cell is the flags, encoded as follows:
bits[3:0] trigger type and level flags.
1 = low-to-high edge triggered
2 = high-to-low edge triggered (invalid for SPIs)
4 = active high level-sensitive
8 = active low level-sensitive (invalid for SPIs).
bits[15:8] PPI interrupt cpu mask. Each bit corresponds to each of
the 8 possible cpus attached to the GIC. A bit set to '1' indicated
the interrupt is wired to that CPU. Only valid for PPI interrupts.
Also note that the configurability of PPI interrupts is IMPLEMENTATION
DEFINED and as such not guaranteed to be present (most SoC available
in 2014 seem to ignore the setting of this flag and use the hardware
default value).
关于linux - #interrupt-cells 是 2 但中断是一个 3 元组,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/51660095/