如何使用Linux内核模块获取盒盖状态? [英] How to get lid state using linux kernel module?

问题描述

我可以通过读取/proc/acpi/button/lid/LID0/state文件来读取笔记本电脑盖的状态.现在，我想从内核模块中读取它.

I can read the status of my laptop lid by reading /proc/acpi/button/lid/LID0/state file. Now I want to read it from kernel module.

我在内核源代码中找到了源文件drivers/acpi/button.c.但是我仍然不知道如何使用它.导出acpi_lid_notifier_register, acpi_lid_notifier_unregiste和acpi_lid_open函数.

I found the source file drivers/acpi/button.c in kernel source. But still I didn't understand how to use it. It exporting acpi_lid_notifier_register, acpi_lid_notifier_unregiste and acpi_lid_open functions.

如何为盖状态编写模块?

How to write a module for lid state?

推荐答案

acpi_lid_open returns 0 (closed), 1 (open), or a negative error number (unsupported).

要使用通知程序，您需要在模块中定义一个回调函数和一个通知程序块:

To use the notifier, you would define a callback function and a notifier block in your module:

static int yourmodule_lid_notify(struct notifier_block *nb, unsigned long val, void *unused) {
    // Whatever you wanted to do here
}
static struct notifier_block lid_notifier;

// Somewhere in a function, likely your module init function:
lid_notifier.notifier_call = yourmodule_lid_notify;
if (acpi_lid_notifier_register(&lid_notifier)) {
    // TODO: Handle the failure here
}

// TODO: Unregister the notifier when your module is unloaded:
acpi_lid_notifier_unregister(&lid_notifier);

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