GPIO中断使用的Sample Code

1. 在kernel/drivers/sstar/目录下新增目录test_gpioirq，放入mdrv_gpioirq.c。

2. 修改Makefile，增加一行：oby-m += test_gpioirq/

3. Make modules即可生成ko

   mdrv_gpioirq.c代码如下：

   #include < linux/module.h >  
   #include < linux/moduleparam.h >  
   #include < linux/types.h >  
   #include < linux/gpio.h >  
   #include < linux/interrupt.h >  
   #include "../include/ms_types.h"  
   //#include "../include/infinity6/gpio.h"  
   #include "../include/infinity6e/gpio.h"
   
   static int test_gpio_num = PAD_SAR_GPIO3;  
   static struct work_struct work;  
   static irqreturn_t gpio_keys_isr(int irq, void *dev_id)  
   {  
       struct irq_data *data;  
       int gpio_state;  
       int flag;  
       int gpio_num = *(int *)dev_id;  
       gpio_state = gpio_get_value(gpio_num);   
       printk("======gpio_keys_isr:irq=%d gpio num=%d state=%d=====\n",irq,gpio_num,gpio_state);  
       // 需要在中断服务程序中立即处理的动作放在这里
   
       if(!gpio_state)  
       {  
           flag=IRQF_TRIGGER_RISING;  
       }  
       else  
       {  
           flag=IRQF_TRIGGER_FALLING;  
       }  
       data = irq_get_irq_data(irq);  
       data->chip->irq_set_type(data, flag);  
       data->chip->irq_ack(data);
   
       schedule_work(&work);  
       return 0;  
   }  
   static void gpioirq_work_func(struct work_struct *work)  
   {  
       printk("Ok!\n");  
       //不需要在中断服务程序中立即处理，放在工作队列里处理。  
   }  
   int MDrv_GPIO_To_Irq(U8 u8IndexGPIO);  
   static int __init gpioirq_init(void)  
   {  
       const char *desc = "mdrv_gpioirq";  
       unsigned long irqflags;  
       int irq, error;   
       error = gpio_request(test_gpio_num, desc);  
       if (error < 0)  
       {  
           printk(KERN_ERR "failed to request GPIO %d, error %d\n", test_gpio_num, error);  
           goto fail2;  
       }  
       error = gpio_direction_input(test_gpio_num);  
       if (error < 0)  
       {  
           printk(KERN_ERR "failed to configure direction for GPIO %d, error %d\n", test_gpio_num, error);  
           goto fail3;  
       }  
       irq = MDrv_GPIO_To_Irq((U8)test_gpio_num);  
       if (irq < 0)   
       {  
           error = irq;  
           printk(KERN_ERR "Unable to get irq number for GPIO %d, error %d\n", test_gpio_num, error);  
           goto fail3;  
       }
   
       irqflags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING ;
   
       INIT_WORK(&work, gpioirq_work_func);  
       error = request_threaded_irq(irq, NULL, gpio_keys_isr, irqflags, desc, &test_gpio_num);  
       if (error < 0)   
       {  
           printk(KERN_ERR "Unable to claim irq %d; error %d\n", irq, error);  
           goto fail3;  
       }  
       printk(KERN_DEBUG"request_threaded_irq %d success\n",irq);  
       return 0;  
   fail3:  
       gpio_free(test_gpio_num);  
   fail2:  
       return error;  
   }
   
   static void __exit gpioirq_exit(void)  
   {  
       int irq=0;  
       irq = MDrv_GPIO_To_Irq((U8)test_gpio_num);  
       printk(KERN_DEBUG"free_irq %d\n",irq);  
       free_irq(irq, &test_gpio_num);  
       gpio_free(test_gpio_num);  
       cancel_work_sync(&work);  
   }
   
   module_init(gpioirq_init);  
   module_exit(gpioirq_exit);  
   MODULE_DESCRIPTION("Interrupted GPIO driver");  
   MODULE_LICENSE("GPL v2");