linux 外部中断例子
code:
#include <linux/kernel.h> #include <linux/module.h> #include <linux/cdev.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/syscalls.h>#include <linux/interrupt.h> #include <linux/gpio.h>#include <linux/of_gpio.h>#include <linux/of_platform.h>#include <linux/uaccess.h> #include <linux/string.h> #include <mach/gpio.h>#include <mach/irqs.h>#define GPIO_TO_PIN(bank, gpio) (32 * (bank) + (gpio))struct fpga_key_dev { struct cdev cdev; dev_t devno; char test[20]; struct class *fpga_key_class; struct fasync_struct *async_queue;int message_cdev_open;}; irqreturn_t irq_handler(int irqno, void *dev_id){printk("fpga key down\n");return IRQ_HANDLED;}static int fpga_key_open(struct inode *node, struct file *fd) { struct fpga_key_dev *dev;printk("fpga_key_open()++\n"); printk("node->i_cdev = %x\n", (unsigned int)node->i_cdev);dev = container_of(node->i_cdev, struct fpga_key_dev, cdev);printk("dev->cdev = %x\n", (unsigned int)&dev->cdev);printk("dev = %x\n", (unsigned int)dev);if (!dev->message_cdev_open) {dev->message_cdev_open = 1;fd->private_data = dev;}else{return -EFAULT;}printk("test[20] = %s\n",dev->test); printk("fpga_key_open()--\n"); return 0; } static ssize_t fpga_key_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr) { char temp_buffer [20]; int print_size = 0; struct fpga_key_dev *dev = fd->private_data; printk("fpga_key_wirte()++\n"); if(len > 20) print_size = 20; else print_size = len; printk("print_size = %d; len = %d\n", print_size, len); if(copy_from_user(temp_buffer, buf, print_size)) return -EFAULT; if (dev->async_queue)kill_fasync(&dev->async_queue, SIGIO, POLL_IN); printk("writing data:%s", temp_buffer); printk("fpga_key_wirte()--\n"); return print_size; } static ssize_t fpga_key_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr) { char *temp_buffer = "Hello fpga_key_read !\n"; int print_size = 0; printk("fpga_key_read()++\n"); if(len > strnlen(temp_buffer,20)) print_size = strnlen(temp_buffer,20); else print_size = len; printk("print_size = %d; len = %d\n", print_size, len); if(copy_to_user(buf, temp_buffer, print_size)) return -EFAULT; printk("%s", temp_buffer); printk("fpga_key_read()--\n"); return print_size; } static int fpga_key_fasync(int fd, struct file *filp, int mode){struct fpga_key_dev*dev = filp->private_data;printk("fpga_key_fasync()++\n");fasync_helper(fd, filp, mode, &dev->async_queue); printk("fpga_key_fasync()--\n");return 0;}static int fpga_key_release(struct inode *node, struct file *fd) { struct fpga_key_dev *dev = fd->private_data;printk("fpga_key_release()++\n"); dev->message_cdev_open = 0;fpga_key_fasync(-1, fd, 0); printk("fpga_key_release()--\n"); return 0; } struct file_operations meassage_operatons = { .owner = THIS_MODULE, .open = fpga_key_open, .write = fpga_key_write, .read = fpga_key_read, .fasync = fpga_key_fasync, .release = fpga_key_release, }; struct fpga_key_dev fpga_key_dev; static int __init fpga_key_init(void) { struct fpga_key_dev * dev; char * temp_char = "hello world\n";int ret = 0;int inter = 0; printk("fpga_key_to_app_init(void)++\n"); dev = &fpga_key_dev; strcpy(dev->test, temp_char);; alloc_chrdev_region(&dev->devno, 0, 1, "fpga_key_to_app"); cdev_init(&dev->cdev, &meassage_operatons); cdev_add(&dev->cdev, dev->devno, 1); dev->fpga_key_class = class_create(THIS_MODULE, "fpga_key_class"); if(IS_ERR(dev->fpga_key_class)) { printk("Err: failed in creating class./n"); goto fail1; } device_create(dev->fpga_key_class, NULL, dev->devno, NULL, "fpga_key"); //init irqret = gpio_request(GPIO_TO_PIN(1, 27), "fpga_key_inter");if(ret){printk("gpio_request() failed !\n");goto fail1;}ret = gpio_direction_input(GPIO_TO_PIN(1, 27));if(ret){printk("gpio_direction_input() failed !\n");goto fail2;}inter = gpio_to_irq(GPIO_TO_PIN(1, 27));if(inter < 0){printk("gpio_to_irq() failed !\n");ret = inter;goto fail2;}printk("inter = %d", inter);ret = request_irq(inter, irq_handler, IRQF_TRIGGER_FALLING | IRQF_SHARED, "fpga_key_inter", &dev->devno); if(ret){printk("request_irq() failed ! %d\n", ret);goto fail2;} printk("fpga_key_to_app_init(void)--\n"); return 0; fail2:gpio_free(GPIO_TO_PIN(1, 27));fail1: device_destroy(dev->fpga_key_class, dev->devno); class_destroy(dev->fpga_key_class); cdev_del(&dev->cdev); unregister_chrdev_region(dev->devno, 1); return ret;} static void __exit fpga_key_exit(void) { struct fpga_key_dev *dev = &fpga_key_dev; printk("fpga_key_to_app_exit(void)++\n"); free_irq(AM33XX_IRQ_GPIO1_1, NULL); gpio_free(GPIO_TO_PIN(1, 27)); device_destroy(dev->fpga_key_class, dev->devno); class_destroy(dev->fpga_key_class); cdev_del(&dev->cdev); unregister_chrdev_region(dev->devno, 1); printk("fpga_key_to_app_exit(void)--\n"); } module_init(fpga_key_init); module_exit(fpga_key_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Driver Monkey"); MODULE_DESCRIPTION("Test fpga_key to App");