[ARM笔记]设备IO端口和IO内存的访问

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___________________________ /在设备驱动卸载或release()函数中调用

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| release_region() | /

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IO端口的访问流程(映射到内存空间)

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| request_mem_region()等 | \

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| \ 在设备驱动模块加载或open()函数中进行

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| ioremap()等 |/

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| ioread8、ioread16、 | 在设备驱动初始化、write()、read()、ioctl等函数中调用

| ioread32、iowrite8等 |

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| iounmap() | \

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______________________________ /在设备驱动卸载或release()函数中调用

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| release_mem_region() | /

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