按键唤醒kernel系统-e3x0-button

源代码路径

https://android.googlesource.com/kernel/msm/+/android-4.4/drivers/input/misc/e3x0-button.c

android / kernel / msm / android-4.4 / . / drivers / input / misc / e3x0-button.c/* * Copyright (c) 2014, National Instruments Corp. All rights reserved. * * Driver for NI Ettus Research USRP E3x0 Button Driver * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */#include <linux/device.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/input.h>#include <linux/interrupt.h>#include <linux/of.h>#include <linux/slab.h>static irqreturn_t e3x0_button_release_handler(int irq, void *data){struct input_dev *idev = data;input_report_key(idev, KEY_POWER, 0);input_sync(idev);return IRQ_HANDLED;}static irqreturn_t e3x0_button_press_handler(int irq, void *data){struct input_dev *idev = data;input_report_key(idev, KEY_POWER, 1);pm_wakeup_event(idev->dev.parent, 0);input_sync(idev);return IRQ_HANDLED;}static int __maybe_unused e3x0_button_suspend(struct device *dev){struct platform_device *pdev = to_platform_device(dev);if (device_may_wakeup(dev))enable_irq_wake(platform_get_irq_byname(pdev, "press"));return 0;}static int __maybe_unused e3x0_button_resume(struct device *dev){struct platform_device *pdev = to_platform_device(dev);if (device_may_wakeup(dev))disable_irq_wake(platform_get_irq_byname(pdev, "press"));return 0;}static SIMPLE_DEV_PM_OPS(e3x0_button_pm_ops, e3x0_button_suspend, e3x0_button_resume);static int e3x0_button_probe(struct platform_device *pdev){struct input_dev *input;int irq_press, irq_release;int error;irq_press = platform_get_irq_byname(pdev, "press");if (irq_press < 0) {dev_err(&pdev->dev, "No IRQ for 'press', error=%d\n",irq_press);return irq_press;}irq_release = platform_get_irq_byname(pdev, "release");if (irq_release < 0) {dev_err(&pdev->dev, "No IRQ for 'release', error=%d\n",irq_release);return irq_release;}input = devm_input_allocate_device(&pdev->dev);if (!input)return -ENOMEM;input->name = "NI Ettus Research USRP E3x0 Button Driver";input->phys = "e3x0_button/input0";input->dev.parent = &pdev->dev;input_set_capability(input, EV_KEY, KEY_POWER);error = devm_request_irq(&pdev->dev, irq_press, e3x0_button_press_handler, 0, "e3x0-button", input);if (error) {dev_err(&pdev->dev, "Failed to request 'press' IRQ#%d: %d\n",irq_press, error);return error;}error = devm_request_irq(&pdev->dev, irq_release, e3x0_button_release_handler, 0, "e3x0-button", input);if (error) {dev_err(&pdev->dev, "Failed to request 'release' IRQ#%d: %d\n",irq_release, error);return error;}error = input_register_device(input);if (error) {dev_err(&pdev->dev, "Can't register input device: %d\n", error);return error;}platform_set_drvdata(pdev, input);device_init_wakeup(&pdev->dev, 1);return 0;}static int e3x0_button_remove(struct platform_device *pdev){device_init_wakeup(&pdev->dev, 0);return 0;}#ifdef CONFIG_OFstatic const struct of_device_id e3x0_button_match[] = {{ .compatible = "ettus,e3x0-button", },{ }};MODULE_DEVICE_TABLE(of, e3x0_button_match);#endifstatic struct platform_driver e3x0_button_driver = {.driver= {.name= "e3x0-button",.of_match_table = of_match_ptr(e3x0_button_match),.pm= &e3x0_button_pm_ops,},.probe= e3x0_button_probe,.remove= e3x0_button_remove,};module_platform_driver(e3x0_button_driver);MODULE_LICENSE("GPL v2");MODULE_AUTHOR("Moritz Fischer <[e-mail]>");MODULE_DESCRIPTION("NI Ettus Research USRP E3x0 Button driver");MODULE_ALIAS("platform:e3x0-button");

pm_wakeup_event(idev->dev.parent, 0);

if (device_may_wakeup(dev))enable_irq_wake(platform_get_irq_byname(pdev, "press"));

if (device_may_wakeup(dev))disable_irq_wake(platform_get_irq_byname(pdev, "press"));

device_init_wakeup(&pdev->dev, 1);

Subsystem / Driver control:- device_init_wakeup(dev, bool)- enable_irq_wake()- disable_irq_wake()设置设备是否支持唤醒功能，以及是否开启irq唤醒功能

When wakeup occurs (e.g. in ISR):- pm_wakeup_event()当中断发生时，调用此函数唤醒kernel

Enable / disable from user space:- /sys/devices/.../power/wakeup通过节点进行操作