嵌入式LINUX驱动开发（中断处理函数）

一、函数、头文件及说明

//头文件位置：include/linux/interrupt.h extern int __must_check request_threaded_irq(unsigned int irq, irq_handler_t handler,\
                     irq_handler_t thread_fn,\ unsigned long flags, const char *name, void *dev); static inline int __must_check \ request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev) { return request_threaded_irq(irq, handler, NULL, flags, name, dev); } /*
参数：
irq : 中断号，获取外部中断号使用的函数 ：
     static inline int gpio_to_irq(unsigned gpio);//头文件位置：include/linux/gpio.h
irq_handler_t : 中断处理函数 ：
                typedef irqreturn_t (*irq_handler_t)(int, void *);
                使用方法：
                         static irqretrun_t irq_func(int args,void * argv);//args:全局的整数，argv:全局指针
flags:
      #define IRQF_TRIGGER_NONE       0x00000000             //没有中断
      #define IRQF_TRIGGER_RISING     0x00000001             //上升沿触发
      #define IRQF_TRIGGER_FALLING    0x00000002             //下降沿触发
      #define IRQF_TRIGGER_HIGH       0x00000004             //高电平触发
      #define IRQF_TRIGGER_LOW        0x00000008             //低电平触发
      #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
                                      IRQF_TRIGGER_RISING |RQF_TRIGGER_FALLING)
      #define IRQF_TRIGGER_PROBE      0x00000010
 dev :向中断处理函数传递的参数     
*/ 

二、编译举例：

#include <linux/init.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/gpio.h> #include <cfg_type.h> /*定义按键信息*/ struct btn_srouce{ char *name; int gpio ; }; struct btn_srouce btn_info[] = { { .name = "BTN1", .gpio = PAD_GPIO_A +28 }, { .name = "BTN2", .gpio = PAD_GPIO_B +30 }, { .name = "BTN3", .gpio = PAD_GPIO_B +31 }, { .name = "BTN4", .gpio = PAD_GPIO_B +9 } }; /*定义LED灯信息*/ struct led_source { char *name; int gpio ; }; struct led_source led_info[] = { { .name = "LED1", .gpio = PAD_GPIO_B +26 }, { .name = "LED2", .gpio = PAD_GPIO_C +12 }, { .name = "LED3", .gpio = PAD_GPIO_C +11 }, { .name = "LED4", .gpio = PAD_GPIO_C +7 } }; static int irq;//定义中断号变更  /*定义中断处理函数*/ static irqreturn_t irq_func(int args,void * argv){ struct led_source *led_num = (struct led_source *) argv;//保存传递来的的形参地址 gpio_set_value(led_num->gpio,(1 - gpio_get_value(led_num->gpio)));//获取当前灯的状态信息，当为0时，设置为1，当为1时设置为0；即开/关状态切换 printk("%s ,当前%s状态为%s\n",__func__,led_num->name,\ gpio_get_value(led_num->gpio) ? "关" :"开"); return IRQ_HANDLED; //返回值说明，见附A.1 } static int btn_led_init(void){ int i = 0; for(; i<ARRAY_SIZE(btn_info);i++){ /*LED灯初始化*/ gpio_request(led_info[i].gpio,led_info[i].name); gpio_direction_output(led_info[i].gpio,1); /*按键初始化*/ gpio_request(btn_info[i].gpio,btn_info[i].name); irq = gpio_to_irq(btn_info[i].gpio); request_irq(irq,irq_func,IRQF_TRIGGER_LOW,\
                    btn_info[i].name,&led_info[i]); } return 0; } static void btn_led_exit(void){ int i = 0; for(; i <ARRAY_SIZE(btn_info);i++){ /*释放LED灯占用的GPIO资源*/ gpio_set_value(led_info[i].gpio,1); gpio_free(led_info[i].gpio); /*释放按键占用的GPIO资源*/ irq = gpio_to_irq(btn_info[i].gpio); free_irq(irq,&led_info[i]); gpio_set_value(btn_info[i].gpio,1); gpio_free(btn_info[i].gpio); } } module_init(btn_led_init); module_exit(btn_led_exit); MODULE_LICENSE("GPL"); 

附 A.1

//源码位置：include/linux/irqreturn.h /**
 * enum irqreturn
 * @IRQ_NONE            interrupt was not from this device
 * @IRQ_HANDLED         interrupt was handled by this device
 * @IRQ_WAKE_THREAD     handler requests to wake the handler thread
 */ enum irqreturn { IRQ_NONE = (0 << 0), IRQ_HANDLED = (1 << 0), IRQ_WAKE_THREAD = (1 << 1), }; typedef enum irqreturn irqreturn_t; 

本文地址：https://blog.csdn.net/weixin_47273317/article/details/107908456