2、JZ2440 按键驱动（查询）

 

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 <asm/uaccess.h>
 7 #include <asm/irq.h>
 8 #include <asm/io.h>
 9 #include <asm/arch/regs-gpio.h>
10 #include <asm/hardware.h>
11 
12 static struct class *key_dev1_class;
13 static struct class_device *key_dev1_class_dev;
14 
15 volatile unsigned long *gpfcon;
16 volatile unsigned long *gpfdat;
17 
18 volatile unsigned long *gpgcon;
19 volatile unsigned long *gpgdat;
20 
21 static int key_dev1_open(struct inode *inode, struct file *file)
22 {
23     /* 配置GPF0,2为输入引脚 */
24     *gpfcon &= ~((0x3<<(0*2)) | (0x3<<(2*2)));
25 
26     /* 配置GPG3,11为输入引脚 */
27     *gpgcon &= ~((0x3<<(3*2)) | (0x3<<(11*2)));
28     return 0;
29 }
30 ssize_t key_dev1_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
31 {
32     /* 返回4个引脚的电平 */
33     unsigned char key_vals[4];
34     int regval;
35 
36     if (size != sizeof(key_vals))
37         return -EINVAL;
38 
39     /* 读GPF0,2 */
40     regval = *gpfdat;
41     key_vals[0] = (regval & (1<<0)) ? 1 : 0;
42     key_vals[1] = (regval & (1<<2)) ? 1 : 0;
43     
44 
45     /* 读GPG3,11 */
46     regval = *gpgdat;
47     key_vals[2] = (regval & (1<<3)) ? 1 : 0;
48     key_vals[3] = (regval & (1<<11)) ? 1 : 0;
49 
50     copy_to_user(buf, key_vals, sizeof(key_vals));
51     
52     return sizeof(key_vals);
53 }
54 
55 static struct file_operations key_dev1_fops = 
56 {
57     .owner = THIS_MODULE,
58     .open = key_dev1_open,
59     .read = key_dev1_read,
60 };
61 
62 int major; 
63 static int __init key_dev1_init(void)
64 {
65     major = register_chrdev(0,"key_dev1",&key_dev1_fops);
66     key_dev1_class = class_create(THIS_MODULE,"key_dev1");
67     key_dev1_class_dev = class_device_create(key_dev1_class,NULL,MKDEV(major,0),NULL,"key_dev1");
68 
69     gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
70     gpfdat = gpfcon + 1;
71 
72     gpgcon = (volatile unsigned long *)ioremap(0x56000060, 16);
73     gpgdat = gpgcon + 1;
74     return 0;
75 }
76 
77 static void __exit key_dev1_exit(void)
78 {
79     unregister_chrdev(major,"key_dev1");
80     class_device_unregister(key_dev1_class_dev);
81     class_destroy(key_dev1_class);
82     iounmap(gpfcon);
83     iounmap(gpgcon);
84 
85 }
86 
87 module_init(key_dev1_init);
88 module_exit(key_dev1_exit);
89 MODULE_LICENSE("GPL");
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测试代码

 1 #include <sys/types.h>
 2 #include <sys/stat.h>
 3 #include <fcntl.h>
 4 #include <stdio.h>
 5 
 6 /* seconddrvtest 
 7   */
 8 int main(int argc, char **argv)
 9 {
10     int fd;
11     unsigned char key_vals[4];
12     int cnt = 0;
13     
14     fd = open("/dev/key_dev1", O_RDWR);
15     if (fd < 0)
16     {
17         printf("can't open!\n");
18     }
19 
20     while (1)
21     {
22         read(fd, key_vals, sizeof(key_vals));
23         if (!key_vals[0] || !key_vals[1] || !key_vals[2] || !key_vals[3])
24         {
25             printf("%04d key pressed: %d %d %d %d\n", cnt++, key_vals[0], key_vals[1], key_vals[2], key_vals[3]);
26         }
27     }
28     
29     return 0;
30 }
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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_dev1.o
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posted @ 2020-08-01 16:47  季风的杜萨  阅读(104)  评论(0)  编辑  收藏  举报