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ARM-Linux自動(dòng)創(chuàng)建設(shè)備結(jié)點(diǎn)

作者： 時(shí)間：2016-11-20 來(lái)源：網(wǎng)絡(luò) 收藏
硬件平臺(tái)：FL2440

內(nèi)核版本：2.6.28

本文引用地址：http://m.butianyuan.cn/article/201611/318863.htm

主機(jī)平臺(tái)：Ubuntu 11.04

內(nèi)核版本：2.6.39

1、首先配置busybox

busybox
Linux System Utilities --->
[*] mdev
[*] Support /etc/mdev.conf
[*] Support command execution at device addition/removal

2、配置內(nèi)核

3、修改文件系統(tǒng)里的/etc/init.d/rcS

#!/bin/sh
/bin/mount -a
/sbin/ifconfig eth0 192.168.0.3 up
#exec /usr/etc/rc.mouse

4、修改文件系統(tǒng)中/linuxrc文件

#!/bin/sh
#echo "mount /etc as ramfs"
#/bin/mount -n -t ramfs ramfs /etc
#/bin/cp -a /mnt/etc/* /etc

#/bin/mount -n -t ramfs ramfs /var/state/dhcp
#/bin/mount -n -t ramfs ramfs /var/log/boa
#/bin/mount -n -t ramfs ramfs /usr/Setting
#/bin/cp -a /mnt/Setting/* /usr/Setting

#/bin/mount -n -t ramfs ramfs /tmp
#/bin/cp -a /mnt/etc/* /etc

/bin/mount -t proc proc /proc
/bin/mount -t sysfs sysfs /sys
/bin/mount -t tmpfs tmpfs /dev
mkdir /dev/pts
mkdir /dev/shm

/bin/echo /sbin/mdev > /proc/sys/kernel/hotplug
/sbin/mdev -s

exec /sbin/init

4、修改/etcfstab

vi ./etc/fstab
#device mount-point type options dump fsck order
none /dev/pts devpts mode=0622 0 0
tmpfs /dev/shm tmpfs defaults 0 0

這樣編寫驅(qū)動(dòng)時(shí)不用手動(dòng)創(chuàng)建設(shè)備結(jié)點(diǎn)文件了

下面是改寫的使用混雜設(shè)備的ADC驅(qū)動(dòng)程序，這樣可以自動(dòng)創(chuàng)建和刪除設(shè)備結(jié)點(diǎn)了

[cpp]view plaincopy
  1. #include
  2. #include
  4. #include
  5. #include/*創(chuàng)建設(shè)備節(jié)點(diǎn)*/
  6. #include
  7. #include/*定義DECLARE_WAIT_QUEUE_HEAD*/
  8. #include/*定義了irqreturn_t等*/
  9. #includeinterrupt.h>/*request_irqdisable_irqenable_irq*/
  11. #include
  12. #include
  13. #include/*其中包含了#include"mach/irqs.h"*/
  15. #includeadc.h>
  16. #include
  18. #defineADC_MAJOR102
  19. #defineADC_NAME"my_adc"
  20. #defineSUCCESS0
  22. staticintadc_open(structinode*,structfile*);
  23. staticintadc_release(structinode*,structfile*);
  24. staticint__initadc_init(void);
  25. staticint__exitadc_exit(void);
  26. staticssize_tadc_read(structfile*,char*,size_t,loff_t*);
  28. volatileunsignedlongadc_con;
  29. unsignedlongadc_dat0;
  31. intflag;//等待任務(wù)完成標(biāo)志
  33. unsignedlongbuf;//存放轉(zhuǎn)換完成的數(shù)據(jù)
  35. //聲明等待隊(duì)列
  36. DECLARE_WAIT_QUEUE_HEAD(adc_wait);
  38. structclk*adc_clk;
  41. staticirqreturn_tadc_interrupt(intirq,void*dev_id)//中斷處理程序
  42. {
  43. if(flag==0)
  44. {
  45. buf=(readw(adc_dat0)&0x3ff);//讀取轉(zhuǎn)換完成的數(shù)據(jù)
  46. flag=1;
  47. wake_up_interruptible(&adc_wait);//喚醒等待其上的進(jìn)程
  48. printk("Readvalueis%ldn",buf);
  49. }
  50. returnIRQ_HANDLED;
  51. }
  53. staticstructfile_operationsadc_ops=
  54. {
  55. .owner=THIS_MODULE,
  56. .read=adc_read,
  57. .open=adc_open,
  58. .release=adc_release,
  59. };
  60. staticstructmiscdeviceadc_misc=
  61. {
  62. .name=ADC_NAME,
  63. .minor=ADC_MAJOR,
  64. .fops=&adc_ops,
  65. };
  66. staticint__initadc_init(void)
  67. {
  68. intret;
  69. adc_clk=clk_get(NULL,"adc");//獲取時(shí)鐘
  70. clk_enable(adc_clk);//使能時(shí)鐘
  72. ret=misc_register(&adc_misc);//注冊(cè)設(shè)備
  73. if(ret<0)
  74. {
  75. printk("registerdevicefailn");
  76. returnret;
  77. }
  78. adc_con=(unsignedlong)ioremap(0x58000000,4);
  79. adc_dat0=(volatileunsignedlong)ioremap(0x58000000+S3C2410_ADCDAT0,4);
  80. if(!(adc_con&adc_dat0))
  81. {
  82. printk("Failedtoioremapn");
  83. gotohandle;
  84. }
  85. printk("Initialized...n");
  86. returnSUCCESS;
  87. handle:
  88. misc_deregister(&adc_misc);
  89. return-1;
  90. }
  92. staticintadc_open(structinode*inode,structfile*file)//打開設(shè)備函數(shù)
  93. {
  94. //注冊(cè)中斷
  95. intret;
  96. //disable_irq(IRQ_ADC);
  97. //enable_irq(IRQ_ADC);
  98. ret=request_irq(IRQ_ADC,adc_interrupt,IRQF_SHARED,ADC_NAME,1);//注冊(cè)中斷IRQ_ADC在mach/irqs.h中定義
  99. if(ret<0)
  100. {
  101. printk("IRQ%dcannotrequestn",IRQ_ADC);
  102. returnret;
  103. }
  104. returnSUCCESS;
  105. }
  107. staticintadc_release(structinode*inode,structfile*file)//關(guān)閉設(shè)備函數(shù)
  108. {
  109. free_irq(IRQ_ADC,1);//釋放中斷
  110. returnSUCCESS;
  111. }
  113. staticssize_tadc_read(structfile*file,
  114. char*buffer,
  115. size_tlength,
  116. loff_t*offset)//設(shè)備讀取函數(shù)
  117. {
  119. writew((1<<14)|(0x31<<6),adc_con);//設(shè)置ADCCON
  120. writew((readw(adc_con)|0x1),adc_con);//啟動(dòng)AD轉(zhuǎn)換
  121. wait_event_interruptible(adc_wait,flag);
  122. flag=0;
  123. }
  125. staticint__exitadc_exit(void)//驅(qū)動(dòng)卸載函數(shù)
  126. {
  127. iounmap(adc_con);
  128. iounmap(adc_dat0);
  129. misc_deregister(&adc_misc);
  130. clk_disable(adc_clk);
  131. clk_put(adc_clk);
  132. printk("Theadcisunintializedn");
  133. returnSUCCESS;
  134. }
  136. module_init(adc_init);
  137. module_exit(adc_exit);
  138. MODULE_LICENSE("GPL");



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