从设备树获取信息并请求irq [英] Getting information from the device tree and requesting irq

问题描述

在我正在使用的设备树中的一个节点中，字段interrupts是:

In the device tree I am using, in one of its node, the filed interrupts is:

interrupts = <0x0 0x1d 0x4>;

(来自Pynq板的设备树，配备有具有双核ARM A9的ZYnq设备)

(from a device tree of a Pynq board, equipaged with a ZYnq device with a dual-core ARM A9 )

现在，在设备树.probe函数中，我使用Linux内核API:

Now, in the device tree .probe function, I use the Linux kernel API:

irq_line = platform_get_irq(pdev, 0);

，以获取要用于函数request_irq的irq(在 ldd3 <中进行了描述/a>第10章).

in order to get the irq to use for the function request_irq (described in ldd3 chapter 10).

执行irq_line = platform_get_irq(pdev, 0);的一个，得到的值0x2e与设备树的interrupts的字段不匹配.

Ones the irq_line = platform_get_irq(pdev, 0); is executed, I get the value 0x2e that DOESN'T match with the fields of the interrupts of the device tree.

1. <0x0 0x1d 0x4>的确切数字是什么?我知道，根据 elinux.org ，:

1. What are exactly the <0x0 0x1d 0x4> numbers? I know that, in according to elinux.org,:

interrupts(中断)-设备节点的属性，其中包含一系列中断说明符，设备上的每个中断输出信号一个.

interrupts - A property of a device node containing a list of interrupt specifiers, one for each interrupt output signal on the device.

1. 如何获取 irq行以使用(也许从这些数字开始)? irq行与设备树相关吗?

1. How can I get the irq line to use (maybe starting from these numbers)? Is the irq line related to the device tree?

为什么我得到的值与interrupts的任何一个字段都不匹配?

Why am I getting a value that doesn't match with no one of the fields of interrupts?

对不起，我确定我误会了一些重要的话题.并感谢您阅读问题并分享您的知识.

I am sure I am misunderstanding some important topics, I am sorry. And thank you for reading the question and sharing your knowledge.

推荐答案

什么是< 0x0 0x1d 0x4>数字?我知道，根据 到elinux.org，(中断=< 0x0 0x1d 0x4>;)

What are exactly the <0x0 0x1d 0x4> numbers? I know that, in according to elinux.org, (interrupts = <0x0 0x1d 0x4>;)

首先，您需要查看设备节点的中断父对象，该父节点将#interrupt-cells属性，该属性指定对中断源进行编码所需的位数，因此从您的条目开始，中断=< 0x0 0x1d 0x4>;表示以下内容:

Firstly you need to look at the interrupt-parent of the device node, this parent will #interrupt-cells property which specifies number of bits needed to encode a interrupt source, so from your entry interrupts = <0x0 0x1d 0x4>; means the following:

0x0  = shared processor interrupts
0x1d = interrupt number
0x4  = active high level-sensitive/[IRQ_TYPE_LEVEL_HIGH][2] 

我该如何使用irq行(也许从这些数字开始)? irq线与设备树相关吗?

How can I get the irq line to use (maybe starting from these numbers)? Is the irq line related to the device tree?

为什么我得到的值与任何一个字段都不匹配 中断?

Why am I getting a value that doesn't match with no one of the fields of interrupts?

在此处也得到了很好的答复，也引用了

Its well answered here also refer this.

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