linux spi 从机驱动 读到的数据是乱码？请问怎么解决？！

1.                
   
2. static struct class *spi_class;
   
3. static struct cdev spicdev;
   
4. dev_t devno;
   
5. /*****************************************************/
   
6. volatile unsigned long *spi_gpecon=NULL;
   
7. volatile unsigned long *spi_gpedat=NULL;
   
8. volatile unsigned long *spi_gpeup=NULL;
   
9. volatile unsigned long *spi_gpgcon=NULL;
   
10. volatile unsigned long *spi_gpgdat=NULL;
    
11. volatile unsigned long *spi_gpgup=NULL;
    
12. volatile unsigned long *s3c2440_clkcon;
    
13. volatile unsigned long *spi_spcon0;
    
14. volatile unsigned long *spi_spsta0;
    
15. volatile unsigned long *spi_sppin0;
    
16. volatile unsigned long *spi_sppre0;
    
17. volatile unsigned long *spi_sptdat0;
    
18. volatile unsigned long *spi_sprdat0;
    
19. #define SPI_TXRX_READY      (((*spi_spsta0)&0x1) == 0x1)
    
20. #define SPI_CS               (((*spi_gpgdat)&0x4)==0x01)
    
21. 
    
22. 
    
23. /***********nSS_SPI GPG2                SPICLK  GPE13        -26
    
24.                         SPIMOSI GPE12-25        SPIMISO GPE11-24************/
    
25. static int spi_open(struct inode *inode,struct file *filp)
    
26. {
    
27. 
    
28.         *s3c2440_clkcon |=0x40000;//使能SPI
    
29.        
    
30.         *spi_gpecon &=0xF03FFFF;//配置SPI
    
31.     *spi_gpecon |=0xA800000;//
    
32.    // *spi_gpeup &=0xc7ff;//使能上拉电阻
    
33.    
    
34.         *spi_gpgcon|=(3<<4);//配置nSS0
    
35.     //*spi_gpgup &= 0xFB;
    
36.        
    
37.         *spi_sppre0=0x06;    //  > 5M
    
38.         *spi_spcon0=(0<<6)|(0<<5)|(0<<4)|(0<<3)|(1<<2)|(1<<1)|(1<<0);
    
39.         printk("spi_spcon0=%02X\n",(unsigned int)*spi_spcon0);       
    
40.         *spi_sppin0=(0<<2)|(0<<0);
    
41.         printk("spi_sppin0=%02X\n",(unsigned int)*spi_sppin0);
    
42.         return 0;
    
43. }
    
44.   
    
45.   
    
46. 
    
47.   
    
48. static ssize_t spi_read(struct file *filp,char __user *buf,size_t count,loff_t *f_ops)
    
49. {
    
50. 
    
51.     char ch;
    
52.     while(！SPI_TXRX_READY);   
    
53.     ch= (char)*spi_sprdat0;
    
54.     copy_to_user(buf,&ch,1);
    
55.     return 1;
    
56. }
    
57. static int spi_release(struct inode *inode,struct file *filp)
    
58. {
    
59.    
    
60.     printk("<1>release\n");
    
61.     return 0;
    
62. }
    
63. 
    
64. static ssize_t spi_write(struct file *filp,const char __user *buf,size_t count,loff_t *f_ops)
    
65. {
    
66.         return 0;
    
67. }
    
68. static ssize_t spi_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long data)
    
69. {
    
70.     return 0;
    
71. }
    
72. 
    
73. static struct file_operations spi_drv_fops = {
    
74.          .owner=THIS_MODULE,
    
75.          .open=spi_open,
    
76.          .read=spi_read,
    
77.          .ioctl=spi_ioctl,
    
78.          .release=spi_release,
    
79.          .write=spi_write,
    
80. };
    
81. static int __init spi_init(void)
    
82. {
    
83. 
    
84.         int result;
    
85.     result = alloc_chrdev_region(&devno, 0, 1, "spi_drv");
    
86.         if (result < 0)
    
87.         return result;
    
88.         cdev_init(&spicdev, &spi_drv_fops);
    
89.         spicdev.owner = THIS_MODULE;
    
90.         spicdev.ops = &spi_drv_fops;
    
91.         cdev_add(&spicdev, devno, 1);
    
92.         spi_class = class_create(THIS_MODULE, "spi_drv");
    
93.         device_create(spi_class, NULL, devno, NULL, "S3C2440_SPI"); /* /dev/S3C2440_SPI */
    
94.                                
    
95.         s3c2440_clkcon         = (volatile unsigned long *)ioremap(0x4C00000c,3);
    
96.        
    
97.         spi_gpgcon = (volatile unsigned long *)ioremap (0x56000060,4);
    
98.         spi_gpgdat = (volatile unsigned long *)ioremap (0x56000064,2);
    
99.         spi_gpgup = (volatile unsigned long *)ioremap (0x56000068,2);
    
100. 
     
101.         spi_gpecon = (volatile unsigned long *)ioremap (0x56000040,2);
     
102.         spi_gpedat = (volatile unsigned long *)ioremap (0x56000044,1);
     
103.         spi_gpeup = (volatile unsigned long *)ioremap (0x56000048,1);
     
104. 
     
105.     spi_spcon0 = (volatile unsigned long *)ioremap(0x59000000,1);
     
106.     spi_spsta0 = (volatile unsigned long *)ioremap(0x59000004,1);
     
107.     spi_sppin0 = (volatile unsigned long *)ioremap(0x59000008,1);
     
108.     spi_sppre0 = (volatile unsigned long *)ioremap(0x5900000c,1);
     
109.     spi_sptdat0 = (volatile unsigned long *)ioremap(0x59000010,1);
     
110.     spi_sprdat0 = (volatile unsigned long *)ioremap(0x59000014,1);
     
111.        
     
112.     printk("Init spi success！\n");  
     
113.     return result;
     
114. }
     
115. static void __exit spi_exit(void)
     
116. {
     
117.     cdev_del(&spicdev);   
     
118.         unregister_chrdev_region(devno, 1);
     
119.         device_destroy(spi_class,devno);
     
120.         class_destroy(spi_class);
     
121.         iounmap(s3c2440_clkcon);
     
122.         iounmap(spi_gpgcon);
     
123.         iounmap(spi_gpgdat);
     
124.         iounmap(spi_gpgup);
     
125.         iounmap(spi_gpecon);
     
126.         iounmap(spi_gpedat);
     
127.         iounmap(spi_gpeup);
     
128.         iounmap(spi_spcon0);
     
129.         iounmap(spi_spsta0);
     
130.         iounmap(spi_sppin0);
     
131.         iounmap(spi_sppre0);
     
132.         iounmap(spi_sptdat0);
     
133.         iounmap(spi_sprdat0);
     
134.     printk("<1>spi_exit！\n");
     
135. }
     
136. module_init(spi_init);
     
137. module_exit(spi_exit);

建议看一下初始化有没有问题

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我现在也在写一个SPI 从机驱动，小编的代码有很很好的启示