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 13 #define DEVICE_NAME "key_dev2" /* 加载模式后,执行”cat /proc/devices”命令看到的设备名称 */ 14 15 static struct class *key_class; 16 static struct class_device *key_class_dev; 17 18 volatile unsigned long *gpfcon; 19 volatile unsigned long *gpfdat; 20 21 volatile unsigned long *gpgcon; 22 volatile unsigned long *gpgdat; 23 24 /* 创建以个等待队列头 */ 25 static DECLARE_WAIT_QUEUE_HEAD(key_waitq); 26 27 /* 中断事件标志, 中断服务程序将它置1,third_drv_read将它清0 */ 28 static volatile int ev_press = 0; 29 30 struct pin_desc{ 31 unsigned int pin; 32 unsigned int key_val; 33 }; 34 /* 键值: 按下时, 0x01, 0x02, 0x03, 0x04 */ 35 /* 键值: 松开时, 0x81, 0x82, 0x83, 0x84 */ 36 static unsigned char key_val; 37 38 struct pin_desc pins_desc[4] = { 39 {S3C2410_GPF0, 0x01}, 40 {S3C2410_GPF2, 0x02}, 41 {S3C2410_GPG3, 0x03}, 42 {S3C2410_GPG11, 0x04}, 43 }; 44 45 /* 46 * 确定按键值 47 */ 48 static irqreturn_t keys_irq(int irq, void *dev_id) 49 { 50 struct pin_desc * pindesc = (struct pin_desc *)dev_id; 51 unsigned int pinval; 52 53 pinval = s3c2410_gpio_getpin(pindesc->pin); 54 55 if (pinval) 56 { 57 /* 松开 */ 58 key_val = 0x80 | pindesc->key_val; 59 } 60 else 61 { 62 /* 按下 */ 63 key_val = pindesc->key_val; 64 } 65 66 ev_press = 1; /* 表示中断发生了 */ 67 wake_up_interruptible(&key_waitq); /* 唤醒休眠的进程 */ 68 return IRQ_RETVAL(IRQ_HANDLED); 69 } 70 71 static int key_drv2_open(struct inode *inode, struct file *file) 72 { 73 /* 配置GPF0,2为输入引脚 */ 74 /* 配置GPG3,11为输入引脚 */ 75 request_irq(IRQ_EINT0, keys_irq, IRQT_BOTHEDGE, "S2", &pins_desc[0]); 76 request_irq(IRQ_EINT2, keys_irq, IRQT_BOTHEDGE, "S3", &pins_desc[1]); 77 request_irq(IRQ_EINT11, keys_irq, IRQT_BOTHEDGE, "S4", &pins_desc[2]); 78 request_irq(IRQ_EINT19, keys_irq, IRQT_BOTHEDGE, "S5", &pins_desc[3]); 79 80 return 0; 81 } 82 83 ssize_t key_drv2_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 84 { 85 if (size != 1) 86 return -EINVAL; 87 88 /* 如果没有按键动作, 休眠 */ 89 wait_event_interruptible(key_waitq, ev_press); 90 91 /* 如果有按键动作, 返回键值 */ 92 copy_to_user(buf, &key_val, 1); 93 ev_press = 0; 94 return 1; 95 } 96 97 int key_drv2_close(struct inode *inode, struct file *file) 98 { 99 free_irq(IRQ_EINT0, &pins_desc[0]); 100 free_irq(IRQ_EINT2, &pins_desc[1]); 101 free_irq(IRQ_EINT11, &pins_desc[2]); 102 free_irq(IRQ_EINT19, &pins_desc[3]); 103 return 0; 104 } 105 106 107 static struct file_operations sencod_drv_fops = { 108 .owner = THIS_MODULE, /* 这是一个宏,推向编译模块时自动创建的__this_module变量 */ 109 .open = key_drv2_open, 110 .read = key_drv2_read, 111 .release = key_drv2_close, 112 }; 113 114 int major; 115 static int key_drv_init(void) 116 { 117 major = register_chrdev(0, DEVICE_NAME, &sencod_drv_fops); 118 119 key_class = class_create(THIS_MODULE, DEVICE_NAME); 120 121 key_class_dev = class_device_create(key_class, NULL, MKDEV(major, 0), NULL, DEVICE_NAME); /* /dev/keys */ 122 123 gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16); 124 gpfdat = gpfcon + 1; 125 126 gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16); 127 gpgdat = gpgcon + 1; 128 129 return 0; 130 } 131 132 static void key_drv_exit(void) 133 { 134 unregister_chrdev(major, DEVICE_NAME); 135 class_device_unregister(key_class_dev); 136 class_destroy(key_class); 137 iounmap(gpfcon); 138 iounmap(gpgcon); 139 return 0; 140 } 141 142 module_init(key_drv_init); 143 144 module_exit(key_drv_exit); 145 146 MODULE_LICENSE("GPL");
驱动代码
1 #include <sys/types.h> 2 #include <sys/stat.h> 3 #include <fcntl.h> 4 #include <stdio.h> 5 6 /* thirddrvtest 7 */ 8 int main(int argc, char **argv) 9 { 10 int fd; 11 unsigned char key_val; 12 13 fd = open("/dev/key_dev2", O_RDWR); 14 if (fd < 0) 15 { 16 printf("can't open! "); 17 } 18 19 while (1) 20 { 21 read(fd, &key_val, 1); 22 printf("key_val = 0x%x ", key_val); 23 } 24 25 return 0; 26 }
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_dev2.o