Android驱动例子（LED灯控制）（1…

Android驱动例子（LED灯控制）

[日期：2011-04-13]来源：Linux社区  作者：ok138ok

本例子，讲述在Android2.1上完全自已开发一个驱动去控制硬件口并写应用测试该驱动，通过这样一个例子，解析android下的驱动开发流程的应用调用流程，可以说是很好的入门引导

要达到的效果：通过Android的应用，调用驱动程序，在开发板上控制4个LED的亮灭。

一、硬件原理

如上图，通过4个IO口控制这LED，低电平LED亮，

这4个IO口分别是GPM1, GPM2, GPM3, GPM4,

二、驱动程序

1、在kernel文件夹下的driver目录，新键驱动文件夹

# cd kernel_Android_2.6.28.6/drivers

进到开发板的kernel目录，建驱动文件夹

#mkdir ledtest

2、在/driver/ledtest目录下，新建leddriver.c ，leddriver.h , Kconfig,Makefile 等4个文件

leddriver.c

leddriver.c

1. #include <linux/kernel.h>
2. #include <linux/sched.h>
3. #include <linux/timer.h>
4. #include <linux/init.h>            
5. #include <linux/module.h>
6. #include <mach/hardware.h>
7. #include <asm/io.h>
8. #include <asm/uaccess.h>
9. #include <plat/gpio-cfg.h>
10. #include <plat/regs-clock.h>
11. #include <plat/regs-lcd.h>
12. #include <plat/regs-gpio.h>
13. #include <mach/map.h>
14. #include <linux/gpio.h>
15. #include <plat/gpio-bank-m.h>
16. #include <linux/cdev.h>
17. #include <linux/fs.h>//for register_chrdev()
18. #include <linux/device.h>
19. #include <mach/map.h>
20. #include "leddriver.h"
21. #include <linux/miscdevice.h>        
22. #include <linux/watchdog.h>        
23. #include <linux/fs.h>            
24. #defineViberator_MAJOR        97  //?÷éè±?o?
25. #defineSCULL_NR_DEVS           4
26. #defineSCULL_QUANTUM         4000
27. #define SCULL_QSET            1000
28. //---do as the GIOdriver
29. #defineDEVCOUNT                4
30. #defineGIO_MINOR            2    
31. static dev_tdev;        //éê?? μ?μ??÷ éè±? o?
32. static struct cdev *cdev_p;
33. static int openCnt;
34. //--è???±?á?------------
35. intVIB_major  = 97;//we asigment it for test
36. int VIB_minor = 0;
37. int VIB_nr_devs = SCULL_NR_DEVS;
38. int VIB_quantum =SCULL_QUANTUM;
39. int VIB_qset = SCULL_QSET;
40.  
41. static struct class *vib_dev_class;
42. #defineGPNCON  S3C64XX_GPNCON
43. #defineGPNDAT  S3C64XX_GPNDAT
44. #defineGPNPUD  S3C64XX_GPNPUD
45. #define GPMCON S3C64XX_GPMCON
46. #defineGPMDAT  S3C64XX_GPMDAT
47. #define GPMPUD S3C64XX_GPMPUD
48.  
49. #define VIB_ON 0x11
50.   #defineVIB_OFF 0x22
51. static const struct file_operationsGPIO_Viberator_ctl_ops={
52.     .owner        =THIS_MODULE,
53.     .open    =GPIO_VIB_open,
54.     .read    =GPIO_VIB_read,
55.     .write    =GPIO_VIB_write,
56.     .ioctl    =GPIO_VIB_ioctl,
57.     .release    =GPIO_VIB_release,
58. };
59. ssize_t GPIO_VIB_read(struct file * file,char * buf,size_t count,loff_t *f_ops)
60. {
61.     printk("GPIO_VIB_read \r\n");
62.     gpio_direction_output(S3C64XX_GPM(3),0);//
63.     returncount ;
64. }
65. ssize_t GPIO_VIB_write(struct file *file,const char * buf, size_t count,loff_t *f_ops)
66. {
67.       printk("GPIO_VIB_write \r\n");
68.       gpio_direction_output(S3C64XX_GPM(3),1);//
69.    return count;
70. }
71.  
72. //ssize_t GPIO_VIB_ioctl(structinode *  inode,struct file *file,unsigned int cmd, long data)
73. static int GPIO_VIB_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
74. {
75.     printk(KERN_ERR"VIB:GPIO_VIB_ioctl--CMD=%x \n",cmd);
76.     switch(cmd)
77.         {
78.            caseVIB_ON:
79.             gpio_direction_output(S3C64XX_GPM(1),0);//
80.             gpio_direction_output(S3C64XX_GPM(2),0);//
81.             gpio_direction_output(S3C64XX_GPM(3),0);//
82.             gpio_direction_output(S3C64XX_GPM(4),1);//
83.             printk(KERN_ERR"VIB:GPIO_VIB_ioctl--VIB_ON\n");
84.             break;
85.          caseVIB_OFF:
86.             {
87.             printk(KERN_ERR"VIB:GPIO_VIB_ioctl--VIB_OFF\n");
88.             gpio_direction_output(S3C64XX_GPM(1),1);//
89.             gpio_direction_output(S3C64XX_GPM(2),1);//
90.             gpio_direction_output(S3C64XX_GPM(3),1);//
91.             gpio_direction_output(S3C64XX_GPM(4),0);//
92.             break;
93.          }
94.          default:break;
95.                 
96.     }
97.         //gpio_free(S3C64XX_GPN(7));
98. }
99. ssize_t GPIO_VIB_open(struct inode * inode,struct file * file)
100. {
101. //?￡?éêy
102.   //MOD_INC_USE_COUNT;
103.   printk("GPIO_VIB_open()\n");   
104.   return 0;
105. }
106. ssize_t GPIO_VIB_release(struct inode * inode, struct file * file)
107. {
108.    // MOD_DEC_USE_COUNT;//?￡?éêy??
109.      printk("GPIO_VIB_release()\n");   
110.     return0;
111. }
112. static int GPIO_VIB_CTL_init(void)
113. {
114.     intret  = -ENODEV;
115.    int error ;
116.     printk("----------------------------------------------\r\n");
117.     //3?ê??ˉ???ú
118.         s3c_gpio_cfgpin(S3C64XX_GPM(1),S3C_GPIO_SFN(1));//GPM1output
119.         s3c_gpio_cfgpin(S3C64XX_GPM(2),S3C_GPIO_SFN(1));//GPM2output
120.         s3c_gpio_cfgpin(S3C64XX_GPM(3),S3C_GPIO_SFN(1));//GPM3output
121.         s3c_gpio_cfgpin(S3C64XX_GPM(4),S3C_GPIO_SFN(1));//GPM4output
122. #if 1
123. ret =register_chrdev(Viberator_MAJOR, "viberator",&GPIO_Viberator_ctl_ops);
124. if (ret < 0){
125.     printk(KERN_ERR"VIB: unable to get major%d\n", ret);
126.     returnret;
127. }
128. //′′?¨\uc1class
129. vib_dev_class =class_create(THIS_MODULE, "viberator");
130. if (IS_ERR(vib_dev_class)){
131.     unregister_chrdev(Viberator_MAJOR,"capi20");
132.     returnPTR_ERR(vib_dev_class);
133. }
134. //′′?¨?úμ?￡?
135. device_create(vib_dev_class, NULL,MKDEV(Viberator_MAJOR, 0), NULL, "vib");
136. // create a point under/dev/class/vib  
137. //í¨1yé????aá?2?￡??y?ˉ?ó??oó￡??í?á?ú/dev/class/????éú3é\uc1vib?úμ?￡?ó|ó?3ìDò?éò???2ù×÷???t???ù2ù×÷?a???úμ?￡?í¨1y\uc1open,write,read μèoˉêy2ù×÷￡??ê?é?éò??′oó??μ?ó|ó?ê?ày3ìDò?￡
138.   return0;    
139. #endif
140. #if 0
141.     if((error = alloc_chrdev_region(&dev, 0, DEVCOUNT,"vibrate")) <0)
142.         {
143.         printk(KERN_ERR
144.                "VIB:Couldn't alloc_chrdev_region, error=%d\n",
145.                error);
146.         return1;
147.     }
148.          printk("dev= %d  \n",dev);
149.     cdev_p= cdev_alloc();
150.     cdev_p->ops= &GPIO_Viberator_ctl_ops;
151.     error= cdev_add(cdev_p, dev, DEVCOUNT);
152.     if(error) {
153.         printk(KERN_ERR
154.                "VIB:Couldn't cdev_add, error=%d\n", error);
155.         return1;
156.     }
157.  
158.     vib_dev_class= class_create(THIS_MODULE, "vib-dev");
159.     if(IS_ERR(vib_dev_class)) {
160.         res= PTR_ERR(vib_dev_class);
161.         gotoout_unreg_class;
162.     }
163.     return0;
164. #endif
165. out_unreg_class:
166.     class_destroy(vib_dev_class);
167. return 1;
168. }
169.  
170. static int __init S3C6410_VIB_init(void)
171. {
172.     intret = -ENODEV;
173.     //μ÷ó?oˉêy   
174.         printk(KERN_ERR"Auly:S3C6410_VIB_init---\n");
175.     ret= GPIO_VIB_CTL_init();
176.     if(ret)
177.         {
178.         printk(KERN_ERR"Auly: S3C6410_VIB_init--Fail!!!\n");
179.         returnret;
180.     }
181.     return0;
182. }
183. static void __exit cleanup_GPIO_VIB(void)
184. {
185.     //×￠?úéè±?
186.   //  devfs_unregister_chrdev(Viberator_MAJOR,"gpio_vib_ctl");
187. #if 0
188.       cdev_del(cdev_p);
189.     unregister_chrdev_region(dev,DEVCOUNT);
190.     class_destroy(vib_dev_class);
191. #endif
192. device_destroy(vib_dev_class, MKDEV(Viberator_MAJOR, 0));
193. class_destroy(vib_dev_class);
194. unregister_chrdev(Viberator_MAJOR, "viberator");
195. }
196. MODULE_LICENSE("GPL");
197. MODULE_DESCRIPTION("Peter first driver");
198. MODULE_ALIAS_CHARDEV(Viberator_MAJOR, 0);
199.  
200. module_init(S3C6410_VIB_init);
201. module_exit(cleanup_GPIO_VIB);