问题描述
在MFD设备中.我想了解我们如何到达irq base.它是一个随机数吗?
In an MFD device. I wanted to understand, how do we arrive at irq base. Is it a random number.?
请有人解释.
推荐答案
基本上，在尝试为该IRQ号注册ISR之前，首先需要将特定的IRQ号与实际的物理硬件中断相关联.这通常是在Linux内核中使用 irq_domain_add_linear() .
Basically one first needs to associate a particular IRQ number with an actual physical hardware interrupt before attempting to register an ISR for that IRQ number. This is commonly done in the Linux kernel using irq_domain_add_linear().
irq_alloc_desc*() 和 irq_free_desc*() API提供了irq编号分配，但它们不提供对控制器本地IRQ的反向映射的任何支持( hwirq)号插入Linux IRQ号空间.
The irq_alloc_desc*() and irq_free_desc*() APIs provide allocation of irq numbers, but they don't provide any support for reverse mapping of the controller-local IRQ (hwirq) number into the Linux IRQ number space.
Linux内核的当前设计使用单个较大的数字空间，其中为每个单独的IRQ源分配了一个不同的数字.当只有一个中断控制器时，这很简单，但是在具有多个中断控制器的系统中，内核必须确保为每个中断控制器分配了不重叠的Linux IRQ号分配.
The current design of the Linux kernel uses a single large number space where each separate IRQ source is assigned a different number. This is simple when there is only one interrupt controller, but in systems with multiple interrupt controllers the kernel must ensure that each one gets assigned non-overlapping allocations of Linux IRQ numbers.
更多详细信息，请参见Linux内核 文档/IRQ域. txt .
More details in the Linux-kernel Documentation/IRQ-domain.txt.
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