7.【linux驱动】中断
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用GPIOB_31模拟按键功能，设置上拉，下降沿触发
寄存器版本
linux驱动几乎不用管硬件中断了，内核已经帮我们管理好了所有硬件中断号，并且定义了相应的内核中断号，我们只需要看一下内核中断号。
arch/arm/mach-s5p4418/include/mach/s5paa18_irq.h
这里GPIOB_31直接用IRQ_GPIO_B_START + 31就好。 
数据手册中得到下降沿触发值为0b010=2。有关GPIO寄存器的定义和操作可以见这篇文章: #include#include #include #include //含有request_irq、free_irq函数#include //含有IRQ_HANDLED\IRQ_TYPE_EDGE_RISING#include #include #include #include #include MODULE_LICENSE("GPL");#pragma pack(4)static struct GPIO_B{ unsigned int out_put; unsigned int out_enb; unsigned int detect_md_0; unsigned int detect_md_1; unsigned int int_enb; unsigned int event_detect; unsigned int pad_state; unsigned int resv; unsigned int func0; unsigned int func1; unsigned int DETMODEEX; unsigned int DETENB; unsigned int SLEW; unsigned int SLEW_DISABLE_DEFAULT; unsigned int DRV1; unsigned int DRV1_DISABLE_DEFAULT; unsigned int DRV0; unsigned int DRV0_DISABLE_DEFAULT; unsigned int pull_sell; unsigned int PULLSEL_DISABLE_DEFAULT; unsigned int pull_enb;}* gpio_b;#pragma pack()dev_t devid;unsigned int int_num,gpio_b_31_int_num;static irqreturn_t hello_irq(int irq,void * dev_id){ printk("gpiob_31 down,MAJOR:%d MINOR:%d\n",MAJOR((dev_t)dev_id),MINOR((dev_t)dev_id)); return IRQ_HANDLED;}static int __init hello_init(void){ int ret = 0; devid = MKDEV(241, 1); //换算设备号 ret = register_chrdev_region(devid, 1, "char_test");//注册设备，在/proc/drivers下面可以看到 if (ret < 0) goto err0; gpio_b = (struct GPIO_B *)ioremap(0xc001b000,sizeof(struct GPIO_B));//映射地址 gpio_b->func1 |= (1 << 30); //设置gpio功能 gpio_b->out_enb &= ~(1 << 31); //禁用输出 gpio_b->pull_enb |= (1 << 31); //使能上下拉 gpio_b->pull_sell |= (1 << 31); //设置为上拉 gpio_b->int_enb |= (1 << 31); //中断使能 gpio_b->detect_md_1 |= (2 << 30); //中断模式为下降沿触发 gpio_b_31_int_num = IRQ_GPIO_B_START + 31; if (!request_irq(gpio_b_31_int_num,hello_irq,IRQF_DISABLED | IRQF_SHARED,"gpio_irq0",(void *)devid)){ printk("irq registed:%d\n", gpio_b_31_int_num); int_num = gpio_b_31_int_num; }else{ printk("irq regist fail:%d\n",gpio_b_31_int_num); } printk("hello init\n"); return 0; err0: return ret;}static void __exit hello_exit(void){ if(int_num){ free_irq(gpio_b_31_int_num,(void *)devid); //取消中断函数注册 } unregister_chrdev_region(devid, 1); gpio_b->int_enb &= ~(1 << 31); //禁用中断 printk("hello exit\n");}module_init(hello_init);module_exit(hello_exit);
API版本
api版本需要看一下中断模式的设置，从注释看出来下降沿触发依然是2。
arch/arm/mach-s5p4418/soc/gpio.c
#include#include #include #include //含有request_irq、free_irq函数#include //含有IRQ_HANDLED\IRQ_TYPE_EDGE_RISING#include #include #include #include #include MODULE_LICENSE("GPL");dev_t devid;unsigned int int_num,gpio_b_31_int_num;static irqreturn_t hello_irq(int irq,void * dev_id){ printk("gpiob_31 down,MAJOR:%d MINOR:%d\n",MAJOR((dev_t)dev_id),MINOR((dev_t)dev_id)); return IRQ_HANDLED;}static int __init hello_init(void){ int ret = 0; devid = MKDEV(241, 1); //换算设备号 ret = register_chrdev_region(devid, 1, "char_test");//注册设备，在/proc/drivers下面可以看到 if (ret < 0) goto err0; nxp_soc_gpio_set_io_func(PAD_GPIO_B + 31, 1); //设置gpio功能 nxp_soc_gpio_set_io_pull_enb(PAD_GPIO_B + 31, 1); //使能上下拉 nxp_soc_gpio_set_io_pull_sel(PAD_GPIO_B + 31, 1); //设置为上拉 nxp_soc_gpio_set_int_enable(PAD_GPIO_B + 31, 1); //中断使能 nxp_soc_gpio_set_int_mode(PAD_GPIO_B + 31, 2); //中断模式为下降沿触发 gpio_b_31_int_num = IRQ_GPIO_B_START + 31; if (!request_irq(gpio_b_31_int_num,hello_irq,IRQF_DISABLED | IRQF_SHARED,"gpio_irq0",(void *)devid)){ printk("irq registed:%d\n", gpio_b_31_int_num); int_num = gpio_b_31_int_num; }else{ printk("irq regist fail:%d\n",gpio_b_31_int_num); } printk("hello init\n"); return 0; err0: return ret;}static void __exit hello_exit(void){ if(int_num){ free_irq(gpio_b_31_int_num,(void *)devid); //取消中断函数注册 } unregister_chrdev_region(devid, 1); nxp_soc_gpio_set_io_pull_enb(PAD_GPIO_B + 31, 0); //禁用上下拉 nxp_soc_gpio_set_int_enable(PAD_GPIO_B + 31, 0); //禁用中断 printk("hello exit\n");}module_init(hello_init);module_exit(hello_exit);
运行一下
[root@minicoco int_register]# insmod gpiob_31.ko[ 128.636000] irq registed:127[ 128.636000] hello init[root@minicoco int_register]# [ 134.824000] gpiob_31 down,MAJOR:241 MINOR:1[ 135.240000] gpiob_31 down,MAJOR:241 MINOR:1[ 136.444000] gpiob_31 down,MAJOR:241 MINOR:1
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