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GPIO中断

2015-2-2 15:18:28 2705 示波器高电平

0 要写pxa270上的GPIO中断，迟迟没有进展，无奈，从基础开始，先连个按键做简单的中断，但是因为中断号方面的问题，始终看不出效果，没办法，先做个简单的GPIO驱动吧，就让GPIO9号引脚隔两秒变成低电平，再隔两秒变成高电平，很快实现。没什么难度，就是终于有一点可视的效果了（示波器），记录结果，做个基础的滚回点吧。代码如下：（1）驱动程序irq_driver.c #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEVICE_NAME "irq_270" #define IRQ_MAJOR 0 staticint irq_major=IRQ_MAJOR; staticvoid GPIO_init() { GPDR0\|=(0x1<<9); //GPIO第9位置，表输出 GPSR0\|=(0x1<<9); //置高 printk("GPIO_init ok!n"); } staticvoid GPIO_low() { GPCR0\|=(0x1<<9); } staticvoid GPIO_heigh() { GPSR0\|=(0x1<<9); } staticint irq_open(struct inode inode ,struct file file) { printk(DEVICE_NAME"open success!n"); return 0; } staticint irq_release(struct inode inode ,struct file filp) { printk(DEVICE_NAME "release!n"); return 0; } static ssize_t irq_read(struct file filp, char buff, size_t count, loff_t ppos) { printk("user read data from drivern"); return count; } staticint gpio_ioctl(struct inode inode,struct file file,unsignedint cmd,unsignedlong arg) { switch(cmd){ case 0: { GPIO_low(); printk("GPIO to low level!n"); }break; case 1: { GPIO_heigh(); printk("GPIO to high level!n"); }break; default: printk("error cmd numbern");break; } return 0; } staticstruct file_operations irq_fops={ owner: THIS_MODULE, read: irq_read, ioctl: gpio_ioctl, open: irq_open, release: irq_release, }; staticint __init irq_init(void) { int ret=-1; int flags; ret=register_chrdev(irq_major,DEVICE_NAME,&irq_fops); if(ret<0) { printk("pxa270:init_irq failed with %d.n[--kernel--]",ret); return ret; } GPIO_init(); printk(DEVICE_NAME "initializedn"); return 0; } staticvoid __exit irq_exi(void) { unregister_chrdev(irq_major,"GPIO9"); printk(DEVICE_NAME "unload!n"); } module_init(irq_init); module_exit(irq_exi); MODULE_DESCRIPTION("IRQ module"); MODULE_LICENSE("GPL"); （2）测试程序irq_test.c #include #include #include #include #include int main() { int fd; int r_buf[1024]; fd=open("/dev/irq",O_RDONLY); if(fd !=-1); else printf("Device open failure!n"); while(1) { ioctl(fd,0,NULL); sleep(2); ioctl(fd,1,NULL); sleep(2); } close(fd); return 0; } （3）Makefile文件 PWD=$(shell pwd) KERNEL:= /up-techpxa270/kernel/linux-2.6.9 obj-m := irq_driver.o module-objs:=irq_driver.o all: $(MAKE) -C$(KERNEL) M=$(PWD) modules clean: rm .mod.c rm .ko rm .o 运行： insmod irq_driver.ko mknod /dev/irq c 253 0 ./test 卸载： rmmod irq_driver.ko rm /dev/irq 1
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