这几天把外围简单的输入驱动给写了下,... - 程序员联

1、这段时间都在忙驱动了,几个有代表性的简单的外围接口,写写,让我知道什么是所谓的驱动!完全原创,若有转载,请标记出处,若有什么疑问,请联系我:85469843.三峡大学感谢网上朋友的热心帮助,解决了几个硬件方面的疑问!这几天把外围简单的输入驱动给写了下,尽管简单,但还是花了我不少心思呀!/*eint.c*/*实现功能很简单,就是按下接中断的按键后,LED就亮,中间涉及到中断的注册,中断驱动程序的实现.但还没有加入防抖动的功能，实在太懒了！*/#ifndef _KERNEL_#define _KERNEL_#endif#ifndef MODULE#define MODULE#endif#inclu

2、de #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEVICE_MAJOR 253#define DEV_NAME eintstatic int eint_open(struct inode *inode,struct file *filp); static int eint_release(struct inode *inode, struct file *filp);

3、static ssize_t eint_read(struct file *filp,char *buffer,size_t count,loff_t* ppos); static int _init eint_init(void); static void _exit eint_cleanup(void); /static void (*kbdEvent)(void);/void kbdEvent_dummy(void)/#define KBD_TIMER_DELAY (HZ/10)/#define KBD_TIMER_DELAY1 (HZ/100)/#define MAX_KBD_BUF1

4、6/typedef unsigned char KBD_RET;/*typedef structunsigned int kbdStatus;KBD_RET bufMAX_KBD_BUF;unsigned int head,tail;wait_queue_head_t wq;KBD_DEV;static KBD_DEV kbddev;#define BUF_HEAD (kbddev.bufkbddev.head)#define BUF_TAIL (kbddev.bufkbddev.tail)#define INCBUF(x,mod) (+(x)&(mod)-1)static struct ti

5、mer_list kbd_timer;*/ static struct file_operations eint_fops= owner:THIS_MODULE, open:eint_open, release:eint_release, read:eint_read, ; static void isr_kbd(int irq,void *dev_id,struct pt_regs *reg)printk(Occured key board Interrupt,irq=%dn,irq);/*if(kbddev.kbdStatus=KEYSTATUS_UP )KBD_CLOSE_INT();i

6、f(ISKBD_DOWN()kbddev.kbdStatus=KEYSTATUS_DOWNX;kbd_timer.expires=jiffies+KBD_TIMER_DELAY1;add_timer(&kbd_timer);elseKBD_OPEN_INT();*/*(unsigned char*)0xd1000000)=0x00; static int _init eint_init(void) int ret; set_external_irq(IRQ_EINT2,EXT_LOWLEVEL,GPIO_PULLUP_EN);set_external_irq(IRQ_EINT3,EXT_LOW

7、LEVEL,GPIO_PULLUP_EN);/kbdEvent=kbdEvent_dummy; ret=register_chrdev(DEVICE_MAJOR,DEV_NAME,&eint_fops); if (ret0) printk(DEV_NAME cannot get major number!n); return ret; if( check_region( GPIO_F2,1 ) &check_region(GPIO_F3,1) & check_region(0x10000000,1)printk(the port is used by another modulen);retu

8、rn -1; request_region(GPIO_F2,1,DEV_NAME);request_region(GPIO_F3,1,DEV_NAME);request_region(0x10000000,1,DEV_NAME);ret=request_irq(IRQ_EINT2,isr_kbd,SA_INTERRUPT,DEV_NAME,isr_kbd);if(ret) return ret;ret=request_irq(IRQ_EINT3,isr_kbd,SA_INTERRUPT,DEV_NAME,isr_kbd);if(ret) return ret;/*kbddev.head=kbd

9、dev.tail=0;kbddev.kbdStatus=KEYSTATUS_UP;init_waitqueue_head(&(kbddev.wq);init_timer(&kbd_timer);kbd_timer.function=kbd_timer_handler;*/return 0; static void _exit eint_cleanup(void) *(unsigned char*)0xd1000000)=0xff; release_region(GPIO_F2,1); release_region(GPIO_F3,1);release_region(0x10000000,1);

10、free_irq(IRQ_EINT2,DEV_NAME);free_irq(IRQ_EINT3,DEV_NAME);unregister_chrdev(DEVICE_MAJOR,DEV_NAME); static int eint_open(struct inode *inode,struct file *filp) MOD_INC_USE_COUNT; return 0; static int eint_release(struct inode *inode, struct file *filp) MOD_DEC_USE_COUNT;/del_timer(&kbd_timer); print

11、k(release successn); return 0; static ssize_t eint_read(struct file *filp,char *buffer,size_t count,loff_t* ppos) /*retry:if(ascii_key!=z)printk(prepare to copy to user);copy_to_user(buffer,&ascii_key,sizeof(char);return sizeof(char);else/printk(prepare to sleepn);interruptible_sleep_on(&wq);/printk

12、(sleeping!n);if(signal_pending(current)return -ERESTARTSYS;/printk(retry? n);goto retry ;*/return sizeof(char); module_init(eint_init); module_exit(eint_cleanup); /*eint.c*/*测试程序,什么都不做,打开设备后就是等着你去按按键了*/#include #include #include #include /#include static void delay()int i,j,k;for(i=100;i0;i-)for(j=1

13、00;j0;j-)for(k=100;k0;k-)int main(int argc ,char* argv)int fd;char a=0;printf(prepare to open /dev/keybutton n);fd=open(/dev/eint,O_RDONLY);printf(WYQ fd is %dn,fd);if(fd0)printf(keybutton was opened n);while(1)/read(fd,&a,sizeof(a);/printf(%c was read from keyboardn,a);/delay();close(fd);printf(fd

14、was closedn);return 0;/*keybutton.c*/*4X4键盘的驱动,已经加入了防抖动的功能,参考了光盘上的中断处理程序,感谢同学吕贵蓉一起研究了那段恼人的代码!这里面主要是键盘完全没有使用硬件中断,所以只有在open()后不停的轮询,这样就使用了系统内核定时器,而定时器每add_timer()一次,就完了,不能实现每10ms就调用一次扫描操作,所以不得已之下,在中断处理程序里面做了点手脚,你可以看!我想本来应该还要加入原子操作才对的!然后呢,由于是要读外部设备,自然涉及到了阻塞和非阻塞了,这关系到唤醒与睡眠的问题了.这里说的几个问题相信经常编写驱动的高手一定很熟悉了!

15、感谢涂志波师兄借给我的书设备驱动程序，嵌入式系统接口设计与linux驱动程序设计说心底话，真想买一本，但实在太贵了！以后有的话，要考虑收藏一本了！难道真的是书非借不可读也？*/#ifndef _KERNEL_#define _KERNEL_#endif#ifndef MODULE#define MODULE#endif#include #include #include #include #include #include #include #include #include #include #include #include #include #define DEVICE_MAJOR 25

16、1#define DEV_NAME keybuttonstatic int keybutton_open(struct inode *inode,struct file *filp); static int keybutton_release(struct inode *inode, struct file *filp); static ssize_t keybutton_read(struct file *filp,char *buffer,size_t count,loff_t* ppos); static int _init keybutton_init(void); static vo

17、id _exit keybutton_cleanup(void); static char key_get_char(int row,int col);/*#define MAX_KBD_BUF 16typedef unsigned char KBD_RET;typedef struct/unsigned int kbdStatus;KBD_RET bufMAX_KBD_BUF;unsigned int head,tail;wait_queue_head_t wq;static KBD_DEV kbddev;#define BUF_HEAD(kbddev.bufkbddev.head)#def

18、ine BUF_TAIL(kbddev.bufkbddev.tail)#define INCBUF(x,mod)(+(x) & (mod)-1)*/static wait_queue_head_t wq;enum KEYBOARD_SCAN_STATUSKEYBOARD_SCAN_FIRST,KEYBOARD_SCAN_SECOND,KEYBOARD_SCAN_THIRD,KEYBOARD_SCAN_FOURTH;int row = 0;/extern unsigned char output_0x10000000;static unsigned char ascii_key=z, input

19、_key4, input_key14, key_mask = 0x0F;static unsigned char*keyboard_port_scan = (unsigned char*)0xd1000000;static unsigned char*keyboard_port_value = (unsigned char*)0xd1000002;static int keyboard_scan_status4 = KEYBOARD_SCAN_FIRST, KEYBOARD_SCAN_FIRST, KEYBOARD_SCAN_FIRST, KEYBOARD_SCAN_FIRST;static

20、struct timer_list kbd_timer;static char key_get_char(int row, int col)char key = 0;printk(key_get_charn);switch( row )case 0:if(col & 0x01) = 0) key = 0; else if(col & 0x02) = 0) key =A; else if(col & 0x04) = 0) key = B; else if(col & 0x08) = 0) key = F; break;case 1:if(col & 0x01) = 0) key = 7; els

21、e if(col & 0x02) = 0) key = 8; else if(col & 0x04) = 0) key = 9;else if(col & 0x08) = 0) key = E;break;case 2:if(col & 0x01) = 0) key = 4; else if(col & 0x02) = 0) key = 5; else if(col & 0x04) = 0) key = 6; else if(col & 0x08) = 0) key = D; break;case 3:if(col & 0x01) = 0) key = 1; else if(col & 0x0

22、2) = 0) key = 2; else if(col & 0x04) = 0) key = 3; else if(col & 0x08) = 0) key = C; break;default:break;return key;static void recv_key(unsigned char c)unsigned char cc;cc=c;/printk(recv_key recevied char %c,cc);static void Kbd_Scan(unsigned long data)int loopcnt = row, bexit = 0;int temp;/printk(1

23、0ms was past! begin to scan n);del_timer(&kbd_timer);for( loopcnt = row; loopcnt = 4)temp = loopcnt - 4;elsetemp = loopcnt;/printk(temp is %dn,temp);switch(keyboard_scan_statustemp)case KEYBOARD_SCAN_FIRST:/printk(status is %dn,keyboard_scan_statustemp);*keyboard_port_scan = (0x00000001temp); keyboa

24、rd_scan_statustemp = KEYBOARD_SCAN_SECOND;bexit = 1;break;case KEYBOARD_SCAN_SECOND:/ printk(status is %dn,keyboard_scan_statustemp);input_keytemp = (*keyboard_port_value) & key_mask;if(input_keytemp = key_mask)keyboard_scan_statustemp = KEYBOARD_SCAN_FIRST;elsekeyboard_scan_statustemp=KEYBOARD_SCAN

25、_THIRD;printk(some key was down mainly!n);bexit = 1;break;case KEYBOARD_SCAN_THIRD:/ printk(status is %dn,keyboard_scan_statustemp);if (*keyboard_port_value) & key_mask) != input_keytemp) keyboard_scan_statustemp = KEYBOARD_SCAN_FIRST;elseascii_key = key_get_char(temp, input_keytemp);printk(prepare

26、to wake upn);wake_up_interruptible(&wq);/ascii_key=z;printk(has waken up n);printk(ooooooooooooooooothe char is %cn,ascii_key);keyboard_scan_statustemp = KEYBOARD_SCAN_FOURTH;printk(some key was really down);*keyboard_port_scan = (0x00000001temp); bexit = 1;break;case KEYBOARD_SCAN_FOURTH:/ printk(s

27、tatus is %dn,keyboard_scan_statustemp);input_key1temp = (*keyboard_port_value) & key_mask;if(input_key1temp = key_mask)/ get a keyrecv_key(ascii_key);printk(key was up now!n);keyboard_scan_statustemp = KEYBOARD_SCAN_FIRST;else*keyboard_port_scan = (0x00000001temp); bexit = 1;break;if(bexit)break;row

28、 = temp;kbd_timer.expires=jiffies+HZ/100; add_timer(&kbd_timer); static struct file_operations keybutton_fops= owner:THIS_MODULE, open:keybutton_open, release:keybutton_release, read:keybutton_read, ; /*keybutton_init*/ static int _init keybutton_init(void) int ret; ret=register_chrdev(DEVICE_MAJOR,

29、DEV_NAME,&keybutton_fops); if (ret0) printk(DEV_NAME cannot get major number!n); return ret; if( check_region( 0x10000000,1 ) &check_region(0x10000002,1)printk(the port is used by another modulen);return -1; request_region(0x10000000,1,DEV_NAME);request_region(0x10000002,1,DEV_NAME);/*kbddev.head=kb

30、ddev.tail=0;*/init_waitqueue_head(&wq);printk(success to request_regionn);return 0; /*keybutton_cleanup*/static void _exit keybutton_cleanup(void) release_region(0x10000000,1); release_region(0x10000002,1);unregister_chrdev(DEVICE_MAJOR,DEV_NAME); static int keybutton_open(struct inode *inode,struct

31、 file *filp) init_timer(&kbd_timer);kbd_timer.function=Kbd_Scan; kbd_timer.expires=jiffies+HZ/100; add_timer(&kbd_timer); MOD_INC_USE_COUNT; printk(open device keybuttonn);printk(timer has added into systemn);return 0; static int keybutton_release(struct inode *inode, struct file *filp) MOD_DEC_USE_

32、COUNT;/del_timer(&kbd_timer); printk(release successn); return 0; /* static KBD_RET kbdRead(void)KBD_RET kbd_ret;kbd_ret=BUF_TAIL;kbddev.tail=INCBUF(kbddev.tail,MAX_KBD_BUF);return kbd_ret; */static ssize_t keybutton_read(struct file *filp,char *buffer,size_t count,loff_t* ppos) /add_timer(&kbd_time

33、r);/printk(timer has added into systemn);retry:if(ascii_key!=z)printk(prepare to copy to user);copy_to_user(buffer,&ascii_key,sizeof(char);return sizeof(char);else/printk(prepare to sleepn);interruptible_sleep_on(&wq);/printk(sleeping!n);if(signal_pending(current)return -ERESTARTSYS;/printk(retry? n

34、);goto retry ;return sizeof(char); module_init(keybutton_init); module_exit(keybutton_cleanup); keytest.c*/*已经没有什么新意了，测试程序都是这样的了！*/#include #include #include #include /#include static void delay()int i,j,k;for(i=100;i0;i-)for(j=100;j0;j-)for(k=100;k0;k-)int main(int argc ,char* argv)int fd;char a=0;

35、printf(prepare to open /dev/keybutton n);fd=open(/dev/keybutton,O_RDONLY);printf(WYQ fd is %dn,fd);if(fd0)printf(keybutton was opened n);read(fd,&a,sizeof(a);printf(%c was read from keyboardn,a);delay();close(fd);printf(fd was closedn);return 0;adv.c*/*A/D转换的驱动，终于感受了一把转化！太受不了自己了，一个研究生了，居然一直都没有用转换做过东

36、西！哎，人水了，没有办法！原来转换可以用两种机制来实现的，一种是读转换结束标志位，一种是才用转换结束中断，我这个才用的读转换结束标志位，比较简单的一种。我看网上的一个的驱动，两个都用了，我想应该是他错了吧！希望有网友能批评我的观点！*/#ifndef _KERNEL_#define _KERNEL_#endif#ifndef MODULE#define MODULE#endif#include #include #include #include #include #include #include #include #include #include #include #include #i

37、nclude #define DEVICE_MAJOR 252#define DEV_NAME ADVstatic int ADV_open(struct inode *inode,struct file *filp); static int ADV_release(struct inode *inode, struct file *filp); static ssize_t ADV_read(struct file *filp,char *buffer,size_t count,loff_t* ppos); static int _init ADV_init(void); static void _exit ADV_cleanup(void); /static wait_queue_head_t wq;/static struct timer_list kbd_timer; static struct file_o