3、JZ2440 按键驱动（中断）

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");

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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 }

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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

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