驱动
#include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/fb.h> #include <linux/backlight.h> #include <linux/err.h> #include <linux/pwm.h> #include <linux/slab.h> #include <linux/miscdevice.h> #include <linux/delay.h> #include <linux/timer.h> /*timer*/ #include <asm/uaccess.h> /*jiffies*/ #include <linux/delay.h> #include <linux/interrupt.h> //request_irq #include <mach/irqs.h> //中断号，已包含plat/irqs.h #include <linux/fs.h> #include <linux/device.h> //class_create device_create #include <mach/regs-gpio.h> #include <linux/io.h> //ioremap ioread32 iowrite32 #include <linux/sched.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/poll.h> #include <mach/gpio.h> #include <linux/gpio.h> #include <mach/gpio.h> #include <plat/gpio-cfg.h> static struct class *fifthdrv_class; static struct class_device *fifthdrv_class_dev; #if 0 volatile unsigned long *gpfcon; volatile unsigned long *gpfdat; volatile unsigned long *gpgcon; volatile unsigned long *gpgdat; #endif static DECLARE_WAIT_QUEUE_HEAD(button_waitq); /* 中断事件标志, 中断服务程序将它置1，fifth_drv_read将它清0 */ static volatile int ev_press = 0; static struct fasync_struct *button_async; struct pin_desc{ unsigned int pin; unsigned int key_val; }; /* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */ /* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */ static unsigned char key_val; struct pin_desc pins_desc[4] = { {EXYNOS4_GPX3(2), 0x01}, {EXYNOS4_GPX3(3), 0x02}, {EXYNOS4_GPX3(4), 0x03}, {EXYNOS4_GPX3(5), 0x04}, }; /* * 确定按键值 */ static irqreturn_t buttons_irq(int irq, void *dev_id) { struct pin_desc * pindesc = (struct pin_desc *)dev_id; unsigned int pinval; //比如输出一个高电平：gpio_set_value(EXYNOS4X12_GPM4(0),1); //得到输入的值：gpio_get_value(EXYNOS4X12_GPM3(0))? pinval = gpio_get_value(pindesc->pin); if (pinval) { /* 松开 */ key_val = 0x80 | pindesc->key_val; } else { /* 按下 */ key_val = pindesc->key_val; } ev_press = 1; /* 表示中断发生了 */ wake_up_interruptible(&button_waitq); /* 唤醒休眠的进程 */ kill_fasync (&button_async, SIGIO, POLL_IN); return IRQ_RETVAL(IRQ_HANDLED); } static int fifth_drv_open(struct inode *inode, struct file *file) { int ret; ret = request_irq(IRQ_EINT(26), buttons_irq, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, "k1", &pins_desc[0]); ret =request_irq(IRQ_EINT(27), buttons_irq, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, "k2", &pins_desc[1]); ret =request_irq(IRQ_EINT(28), buttons_irq, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, "k3", &pins_desc[2]); ret =request_irq(IRQ_EINT(29), buttons_irq, IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, "k4", &pins_desc[3]); if (ret < 0) { printk("request_irq faild\n"); return -EINVAL; } return 0; } ssize_t fifth_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) { if (size != 1) return -EINVAL; /* 如果没有按键动作, 休眠 */ wait_event_interruptible(button_waitq, ev_press); /* 如果有按键动作, 返回键值 */ copy_to_user(buf, &key_val, 1); ev_press = 0; return 1; } int fifth_drv_close(struct inode *inode, struct file *file) { free_irq(IRQ_EINT(26), &pins_desc[0]); free_irq(IRQ_EINT(27), &pins_desc[1]); free_irq(IRQ_EINT(28), &pins_desc[2]); free_irq(IRQ_EINT(29), &pins_desc[3]); return 0; } static unsigned fifth_drv_poll(struct file *file, poll_table *wait) { unsigned int mask = 0; poll_wait(file, &button_waitq, wait); // 不会立即休眠 if (ev_press) mask |= POLLIN | POLLRDNORM; return mask; } static int fifth_drv_fasync (int fd, struct file *filp, int on) { printk("driver: fifth_drv_fasync\n"); return fasync_helper (fd, filp, on, &button_async); } static struct file_operations sencod_drv_fops = { .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */ .open = fifth_drv_open, .read = fifth_drv_read, .release = fifth_drv_close, .poll = fifth_drv_poll, .fasync = fifth_drv_fasync, }; int major; static int fifth_drv_init(void) { major = register_chrdev(0, "fifth_drv", &sencod_drv_fops); fifthdrv_class = class_create(THIS_MODULE, "fifth_drv"); fifthdrv_class_dev = device_create(fifthdrv_class, NULL, MKDEV(major, 0), NULL, "mybuttons"); /* /dev/buttons */ #if 0 gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16); gpfdat = gpfcon + 1; gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16); gpgdat = gpgcon + 1; #endif return 0; } static void fifth_drv_exit(void) { unregister_chrdev(major, "fifth_drv"); device_destroy(fifthdrv_class, MKDEV(major, 0)); class_destroy(fifthdrv_class); // iounmap(gpfcon); // iounmap(gpgcon); } module_init(fifth_drv_init); module_exit(fifth_drv_exit); MODULE_LICENSE("GPL"); 应用 #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdio.h> #include <poll.h> #include <signal.h> #include <sys/types.h> #include <unistd.h> #include <fcntl.h> /* fifthdrvtest */ int fd; void my_signal_fun(int signum) { unsigned char key_val; read(fd, &key_val, 1); printf("key_val: 0x%x\n", key_val); } int main(int argc, char **argv) { unsigned char key_val; int ret; int Oflags; signal(SIGIO, my_signal_fun); fd = open("/dev/mybuttons", O_RDWR); if (fd < 0) { printf("can't open!\n"); } fcntl(fd, F_SETOWN, getpid()); Oflags = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, Oflags | FASYNC); while (1) { sleep(1000); } return 0; }