文章目录前言代码前言通过gpio的物理按键中断上报一个input事件代码#includelinux/module.h#includelinux/errno.h#includelinux/miscdevice.h#includelinux/kernel.h#includelinux/major.h#includelinux/mutex.h#includelinux/init.h#includelinux/device.h#includelinux/gpio/consumer.h#includelinux/platform_device.h#includelinux/of_gpio.h#includelinux/of_irq.h#includelinux/interrupt.h#includelinux/irq.h#includelinux/delay.h#includelinux/input.h#includelinux/workqueue.h#defineOWNER_NAMEkk_gpio_key#defineIRQ_NAMEkk_vak/** * 私有数据 */structem_gpio_key{intgpio_pin;//pin脚intgpio_irq;//中断号structworkqueue_struct*work_queue;//工作队列structwork_structwork;//类似标识的东西与key_worker关联起来structinput_dev*input_dev;//input接口};/* 工作处理函数 */staticvoidwork_handler(structwork_struct*work){structem_gpio_key*em_keycontainer_of(work,structem_gpio_key,work);intvalue;printk(%s start \n,__func__);//20ms消抖mdelay(20);valuegpio_get_value(em_key-gpio_pin);printk(%s value %d \n,__func__,value);if(value1){//按键松开input_report_key(em_key-input_dev,KEY_VOICECOMMAND,0);input_sync(em_key-input_dev);}elseif(value0){//按键按下input_report_key(em_key-input_dev,KEY_VOICECOMMAND,1);input_sync(em_key-input_dev);}//重新使能中断enable_irq(em_key-gpio_irq);printk(%s end \n,__func__);}/** * 按键按下触发的中断处理 */staticirqreturn_tgpio_key_isr(intirq,void*data){structem_gpio_key*em_keydata;printk(%s start \n,__func__);//关闭中断防止中断嵌套disable_irq_nosync(em_key-gpio_irq);queue_work(em_key-work_queue,em_key-work);printk(%s end \n,__func__);returnIRQ_HANDLED;}/* * 1.中断申请用于获取中断 * 2.创建工作队列用于处理耗时的操作 * 3.创建input用于上报KEY_VOICECOMMAND按下及抬起 */staticintgpio_key_probe(structplatform_device*pdev){intret;structdevice_node*nodepdev-dev.of_node;structem_gpio_key*em_key;structinput_dev*input_dev;printk(%s start \n,__func__);//给私有数据 分配内存em_keydevm_kzalloc(pdev-dev,sizeof(structem_gpio_key),GFP_KERNEL);if(!em_key){ret-ENOMEM;gotodevm_kzalloc_error;}//获取gpio pin脚em_key-gpio_pinof_get_named_gpio(node,irq-gpio,0);if(!gpio_is_valid(em_key-gpio_pin)){printk(%s gpio_pin:%d is invalid\n,__func__,em_key-gpio_pin);ret-EINVAL;gotoof_error;}/** * 中断创建 *///申请gpio引脚retdevm_gpio_request_one(pdev-dev,em_key-gpio_pin,GPIOF_IN,em_key_irq_gpio);if(ret){printk(%s em_gpio_key.gpio_pin:%d request failed \n,__func__,em_key-gpio_pin);gotorequest_error;}else{printk(%s em_gpio_key.gpio_pin:%d request succeed \n,__func__,em_key-gpio_pin);}//获得gpio中断号em_key-gpio_irqgpio_to_irq(em_key-gpio_pin);if(!em_key-gpio_irq){printk(%s .gpio_pin:%d get irq num:%d failed \n,__func__,em_key-gpio_pin,em_key-gpio_irq);gototo_irq_error;}else{printk(%s .gpio_pin:%d get irq num:%d succeed \n,__func__,em_key-gpio_pin,em_key-gpio_irq);}//根据irq申请中断retdevm_request_threaded_irq(pdev-dev,em_key-gpio_irq,NULL,gpio_key_isr,IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING|IRQF_ONESHOT,emdoor-vak,em_key);if(ret0){printk(%s irq num:%d request failed, ret %d \n,__func__,em_key-gpio_irq,ret);gotoirq_error;}//使用工作队列处理中断这里为了及时处理中断单独创建一个em_key-work_queuecreate_workqueue(my_workqueue);if(!em_key-work_queue){printk(KERN_ERR%s Workqueue demo: Failed to create workqueue\n,__func__);return-ENOMEM;}INIT_WORK(em_key-work,work_handler);//把这个数据设置为device的私有数据dev_set_drvdata(pdev-dev,em_key);/** * input创建 */input_devinput_allocate_device();if(!input_dev){printk(%s Failed to allocate memory for input device,__func__);ret-ENOMEM;gotoinput_allocate_error;}input_dev-dev.parentpdev-dev;input_dev-namekk-input;input_dev-id.bustypeBUS_VIRTUAL;__set_bit(EV_SYN,input_dev-evbit);//同步事件__set_bit(EV_KEY,input_dev-evbit);//按键事件__set_bit(EV_REP,input_dev-evbit);//重复事件__set_bit(KEY_VOICECOMMAND,input_dev-keybit);//设置产生哪些按键值retinput_register_device(input_dev);if(ret){printk(%s Input device registration failed,__func__);gotoinput_register_error;}//把这个数据设置为input_dev的私有数据dev_set_drvdata(input_dev-dev,em_key);//将这个input设备接口存起来em_key-input_devinput_dev;enable_irq(em_key-gpio_irq);printk(%s end \n,__func__);return0;input_allocate_error:irq_error:to_irq_error:request_error:of_error:devm_kzalloc_error:returnret;input_register_error:input_free_device(input_dev);input_devNULL;returnret;}staticintgpio_key_remove(structplatform_device*pdev){structem_gpio_key*em_key;intret;//probe中开辟的私有数据内存需要释放em_keydev_get_drvdata(pdev-dev);if(IS_ERR(em_key)){retPTR_ERR(em_key);printk(KERN_ERR %s remove error!\n,__func__);}flush_workqueue(em_key-work_queue);destroy_workqueue(em_key-work_queue);input_unregister_device(em_key-input_dev);input_free_device(em_key-input_dev);input_set_drvdata(em_key-input_dev,NULL);dev_set_drvdata(pdev-dev,NULL);return0;}staticconststructof_device_idgpio_key[]{{.compatiblekk-vak},{},};/* 1. 定义platform_driver */staticstructplatform_drivergpio_keys_driver{.probegpio_key_probe,.removegpio_key_remove,.driver{.nameOWNER_NAME,.of_match_tablegpio_key,},};/* 2. 在入口函数注册platform_driver */staticint__initgpio_key_init(void){interr;printk(%s %s line %d\n,__FILE__,__FUNCTION__,__LINE__);errplatform_driver_register(gpio_keys_driver);returnerr;}/* 3. 有入口函数就应该有出口函数卸载驱动程序时就会去调用这个出口函数 * 卸载platform_driver */staticvoid__exitgpio_key_exit(void){printk(%s %s line %d\n,__FILE__,__FUNCTION__,__LINE__);platform_driver_unregister(gpio_keys_driver);}module_init(gpio_key_init);module_exit(gpio_key_exit);MODULE_LICENSE(GPL);设备树kk_key:kk_key{compatiblekk-vak;statusokay;irq-gpiopio320;};如果没有上拉中断脚会出现不断触发中断的现象需要内部上拉这个中断脚这里是MTK 引脚的配置就不在设备树里做相关的电气属性配置