5、JZ2440按键驱动（异步通知）
驱动代码
1 #include <linux/module.h> 2 #include <linux/kernel.h> 3 #include <linux/fs.h> 4 #include <linux/init.h> 5 #include <linux/delay.h> 6 #include <linux/irq.h> 7 #include <asm/uaccess.h> 8 #include <asm/irq.h> 9 #include <asm/io.h> 10 #include <asm/arch/regs-gpio.h> 11 #include <asm/hardware.h> 12 #include <linux/poll.h> 13 14 #define DEVICE_NAME "key_dev4" /* 加载模式后，执行”cat /proc/devices”命令看到的设备名称 */ 15 16 static struct class *key_class; 17 static struct class_device *key_class_dev; 18 19 volatile unsigned long *gpfcon; 20 volatile unsigned long *gpfdat; 21 22 volatile unsigned long *gpgcon; 23 volatile unsigned long *gpgdat; 24 25 /* 创建以个等待队列头 */ 26 static DECLARE_WAIT_QUEUE_HEAD(key_waitq); 27 28 /* 中断事件标志, 中断服务程序将它置1，third_drv_read将它清0 */ 29 static volatile int ev_press = 0; 30 31 static struct fasync_struct *key_async; 32 33 struct pin_desc{ 34 unsigned int pin; 35 unsigned int key_val; 36 }; 37 /* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */ 38 /* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */ 39 static unsigned char key_val; 40 41 struct pin_desc pins_desc[4] = { 42 {S3C2410_GPF0, 0x01}, 43 {S3C2410_GPF2, 0x02}, 44 {S3C2410_GPG3, 0x03}, 45 {S3C2410_GPG11, 0x04}, 46 }; 47 48 /* 49 * 确定按键值 50 */ 51 static irqreturn_t keys_irq(int irq, void *dev_id) 52 { 53 struct pin_desc * pindesc = (struct pin_desc *)dev_id; 54 unsigned int pinval; 55 56 pinval = s3c2410_gpio_getpin(pindesc->pin); 57 58 if (pinval) 59 { 60 /* 松开 */ 61 key_val = 0x80 | pindesc->key_val; 62 } 63 else 64 { 65 /* 按下 */ 66 key_val = pindesc->key_val; 67 } 68 69 ev_press = 1; /* 表示中断发生了 */ 70 wake_up_interruptible(&key_waitq); /* 唤醒休眠的进程 */ 71 72 kill_fasync (&key_async, SIGIO, POLL_IN); 73 74 return IRQ_RETVAL(IRQ_HANDLED); 75 } 76 77 static int key_dev4_open(struct inode *inode, struct file *file) 78 { 79 /* 配置GPF0,2为输入引脚 */ 80 /* 配置GPG3,11为输入引脚 */ 81 request_irq(IRQ_EINT0, keys_irq, IRQT_BOTHEDGE, "S2", &pins_desc[0]); 82 request_irq(IRQ_EINT2, keys_irq, IRQT_BOTHEDGE, "S3", &pins_desc[1]); 83 request_irq(IRQ_EINT11, keys_irq, IRQT_BOTHEDGE, "S4", &pins_desc[2]); 84 request_irq(IRQ_EINT19, keys_irq, IRQT_BOTHEDGE, "S5", &pins_desc[3]); 85 86 return 0; 87 } 88 89 ssize_t key_dev4_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 90 { 91 if (size != 1) 92 return -EINVAL; 93 94 /* 如果没有按键动作, 休眠 */ 95 wait_event_interruptible(key_waitq, ev_press); 96 97 /* 如果有按键动作, 返回键值 */ 98 copy_to_user(buf, &key_val, 1); 99 ev_press = 0; 100 return 1; 101 } 102 103 int key_dev4_close(struct inode *inode, struct file *file) 104 { 105 free_irq(IRQ_EINT0, &pins_desc[0]); 106 free_irq(IRQ_EINT2, &pins_desc[1]); 107 free_irq(IRQ_EINT11, &pins_desc[2]); 108 free_irq(IRQ_EINT19, &pins_desc[3]); 109 return 0; 110 } 111 112 static unsigned key_dev4_poll(struct file *file, poll_table *wait) 113 { 114 unsigned int mask = 0; 115 poll_wait(file,&key_waitq,wait); 116 if (ev_press) 117 mask |= POLLIN | POLLRDNORM; 118 119 return mask; 120 } 121 122 static int key_dev4_fasync (int fd, struct file *filp, int on) 123 { 124 printk("driver: fifth_drv_fasync\n"); 125 return fasync_helper (fd, filp, on, &key_async); 126 } 127 128 static struct file_operations sencod_drv_fops = { 129 .owner = THIS_MODULE, /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */ 130 .open = key_dev4_open, 131 .read = key_dev4_read, 132 .release = key_dev4_close, 133 .poll = key_dev4_poll, 134 .fasync = key_dev4_fasync, 135 }; 136 137 int major; 138 static int key_drv_init(void) 139 { 140 major = register_chrdev(0, DEVICE_NAME, &sencod_drv_fops); 141 142 key_class = class_create(THIS_MODULE, DEVICE_NAME); 143 144 key_class_dev = class_device_create(key_class, NULL, MKDEV(major, 0), NULL, DEVICE_NAME); /* /dev/keys */ 145 146 gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16); 147 gpfdat = gpfcon + 1; 148 149 gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16); 150 gpgdat = gpgcon + 1; 151 152 return 0; 153 } 154 155 static void key_drv_exit(void) 156 { 157 unregister_chrdev(major, DEVICE_NAME); 158 class_device_unregister(key_class_dev); 159 class_destroy(key_class); 160 iounmap(gpfcon); 161 iounmap(gpgcon); 162 return 0; 163 } 164 165 module_init(key_drv_init); 166 167 module_exit(key_drv_exit); 168 169 MODULE_LICENSE("GPL");
测试代码
1 #include <sys/types.h> 2 #include <sys/stat.h> 3 #include <fcntl.h> 4 #include <stdio.h> 5 #include <poll.h> 6 #include <signal.h> 7 #include <sys/types.h> 8 #include <unistd.h> 9 #include <fcntl.h> 10 11 12 /* fifthdrvtest 13 */ 14 int fd; 15 16 void my_signal_fun(int signum) 17 { 18 unsigned char key_val; 19 read(fd, &key_val, 1); 20 printf("key_val: 0x%x\n", key_val); 21 } 22 23 int main(int argc, char **argv) 24 { 25 unsigned char key_val; 26 int ret; 27 int Oflags; 28 29 signal(SIGIO, my_signal_fun); 30 31 fd = open("/dev/key_dev4", O_RDWR); 32 if (fd < 0) 33 { 34 printf("can't open!\n"); 35 } 36 37 fcntl(fd, F_SETOWN, getpid()); 38 39 Oflags = fcntl(fd, F_GETFL); 40 41 fcntl(fd, F_SETFL, Oflags | FASYNC); 42 43 44 while (1) 45 { 46 sleep(1000); 47 } 48 49 return 0; 50 }
Makefile
1 KERN_DIR = /work/system/linux-2.6.22.6 2 3 all: 4 make -C $(KERN_DIR) M=`pwd` modules 5 6 clean: 7 make -C $(KERN_DIR) M=`pwd` modules clean 8 rm -rf modules.order 9 obj-m += key_dev4.o
