Android驅(qū)動例子(LED燈控制)

1、本例子，講述在An droid 2.1上完全自已開發(fā)一個驅(qū)動去控制硬件口并寫應用測試該驅(qū)動， 通過這樣一個例子，解析an droid下的驅(qū)動開發(fā)流程的應用調(diào)用流程，可以說是很好的入門引導要達到的效果：通過An droid的應用，調(diào)用驅(qū)動程序，在開發(fā)板上控制4個LED的亮滅。、硬件原理r os fI ceit'D6 W LEO07 W LED；nLED4/DH LEDbVDO 10VBA1-LED如上圖，通過 4個10 口控制這LED,低電平LED亮，這 4 個 I0 口分別是 GPM1, GPM2, GPM3, GPM4,二、驅(qū)動程序1、在kernel文件夾下的driver目錄，新鍵驅(qū)

2、動文件夾# cd kernel_ An droid /drivers進到開發(fā)板的kernel目錄，建驅(qū)動文件夾#mkdir ledtest2、在 /driver/ledtest 目錄下，新建 leddriver.c ， leddriver.h , Kconfig, Makefile 等4個文件leddriver.c3.#include<linux/timer.h>4.#include<linux/init.h>/* For _init/_exit/.*/5.#include<linux/module.h>6.#include<mach/

3、hardware.h>7.#include<asm/io.h>8.#include<asm/uaccess.h>9.#includevplat/gpio-cfg.h>10.#includevplat/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>

4、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>/* For MODULE_ALIAS_MISCDEV22.(WATCHDOG_MINOR) */23.#include<linux/watchdog.h>/

5、* For the watchdog specific items */24.#include<linux/fs.h>/* For file operations */25.#defineViberator_MAJOR97/? -ee± ?o?26.#defineSCULL_NR_DEVS427.#defineSCULL_QUANTUM400028.#defineSCULL_QSET100029./-do as the GIO driver30.#defineDEVCOUNT431.#defineGIO_MINOR2/* GIO minor no. */32.static

6、dev_t dev;/ ee ?g ? g ?* ee士 ? o?33.staticstruct cdev *cdev_p;34.staticint openCnt;35./- e?±?d?36.intVIB_major = 97;/we asigment it for VIB_minor = 0;38.intVIB_nr_devs = SCULL_NR_DEVS;39.int VIB_quantum = SCULL_QUANTUM;40.int VIB_qset = SCULL_QSET;41.42.staticstructclass *vib_dev_clas

7、s;43.#defineGPNCON S3C64XX_GPNCON44.#defineGPNDAT S3C64XX_GPNDAT45.#defineGPNPUD S3C64XX_GPNPUD46.#defineGPMCON S3C64XX_GPMCON47.#define GPMDAT S3C64XX_GPMDAT48.#define GPMPUD S3C64XX_GPMPUD49.50.#define VIB_ON 0x1151.#define VIB_OFF 0x2252.staticconst struct file_operations GPIO_Viberator_ctl_ops=5

8、3.owner= THIS_MODULE,54.open = GPIO_VIB_open,55.read =GPIO_VIB_read,56.write =GPIO_VIB_write,57.ioctl = GPIO_VIB_ioctl,58.release =GPIO_VIB_release,59.;60.ssize_t GPIO_VIB_read(struct file * file,char* buf,size_t count,loff_t *f_ops)61.62.printk(" GPIO_VIB_read rn");63.gpio_direction_outpu

9、t(S3C64XX_GPM(3), 0);/64.return count ;65.66.ssize_t GPIO_VIB_write (struct file * file,const char * buf, size_tcount,loff_t * f_ops)67.68.printk(" GPIO_VIB_write rn");69.gpio_direction_output(S3C64XX_GPM(3), 1);/70.return count;71.72.73.ssize_t GPIO_VIB_ioctl(struct inode * inode,struct f

10、ile *file,unsignedint cmd, long data)74.staticint GPIO_VIB_ioctl(struct inode *inode,struct file*file,unsignedint cmd, unsignedlong arg)75.76.printk(KERN_ERR"VIB:GPIO_VIB_ioctl -CMD=%x n",cmd);77.switch (cmd)78.79.case VIB_ON:80.gpio_direction_output(S3C64XX_GPM(1), 0);/81.gpio_direction_o

11、utput(S3C64XX_GPM(2), 0);/82.gpio_direction_output(S3C64XX_GPM(3), 0);/83.gpio_direction_output(S3C64XX_GPM(4), 1);/84.printk(KERN_ERR"VIB:GPIO_VIB_.ioctl -VIB._ONn");85.break ;86.case VIB_OFF:87.88.printk(KERN_ERR"VIB:GPIO_VIB_ioctl -VIB_OFFn");89.gpio_direction_output(S3C64XX_G

12、PM(1), 1);/90.gpio_direction_output(S3C64XX_GPM(2), 1);/91.gpio_direction_output(S3C64XX_GPM(3), 1);/92.gpio_direction_output(S3C64XX_GPM(4), 0);/93.break ;94.95.default : break ;96.97.98./gpio_free(S3C64XX_GPN(7);99.100.ssize_t GPIO_VIB_open(struct inode * inode,struct file* file)101.102./?£ ?

13、eey103.MOD_INC_USE_COUNT;104.printk("GPIO_VIB_open() n");105.return 0;106.107.ssize_t GPIO_VIB_release(structinode * inode,structfile* file)108.109./ MOD_DEC_USE_COUNT;？£ ?ee y?110.printk("GPIO_VIB_release() n");111.return 0;112.113.staticint GPIO_VIB_CTL_init(void )114.115.

14、int ret = -ENODEV;116.int error ;117.printk("rn");118./3? e ?_? 口119.s3c_gpio_cfgpin(S3C64XX_GPM(1), S3C_GPIO_SFN(1);/GPM1 output120.s3c_gpio_cfgpin(S3C64XX_GPM(2), S3C_GPIO_SFN(1);/GPM2 output121.s3c_gpio_cfgpin(S3C64XX_GPM(3), S3C_GPIO_SFN(1);/GPM3 output122.s3c_gpio_cfgpin(S3C64XX_GPM(4

15、), S3C_GPIO_SFN(1);/GPM4 output123.#if1/*?2 i ? ?e?X 2d?y?_*/124.ret=register_chrdev(Viberator_MAJOR,"viberator",& GPIO_Viberator_ctl_ops);125.if(ret < 0) 126.printk(KERN_ERR"VIB: unable to get major %dn",ret);127.return ret;128.129./''?'uc1class130.vib_dev_cla

16、ss = class_create (T HIS_MODULE,"viberator");131.if (IS_ERR(vib_dev_class) 132.unregister_chrdev(Viberator_MAJOR,"capi20");133.return PTR_ERR(vib_dev_class);134.135./ '' ?mM136.device_create(vib_dev_class,NULL, MKDEV(Viberator_MAJOR,0), NULL, "vib");137./ create

17、 a point under /dev/class/vib138./ 廠 1ye?ad?2? £ ?y?-?6?o6 £uc1vib2 ug?£ ?6 | 6?3i Do?eo ?2 uX ?t? u2uX ?a?up£ ? i"1yuc1open ,write,readge oe y2uX22e2e?eo 22' o 6 22 g 2 6 | 6 2 e 2 a y3 i D£?139.return 0;140.#endif141.#if 0 /* X 0 2 d 2 _i 2*/142.if (error = alloc_

18、chrdev_region(&dev, 0, DEVCOUNT,"vibrate") < 0)143.144.printk(KERN_ERR145."VIB: Couldn't alloc_chrdev_region, error=%dn",146.error);147.return 1;148.149.printk("dev = %d n",dev);150.cdev_p = cdev_alloc();151.cdev_p->ops = & GPIO_Viberator_ctl_ops;152.e

19、rror = cdev_add(cdev_p, dev, DEVCOUNT);153.if (error) 154.printk(KERN_ERR155."VIB: Couldn't cdev_add, error=%dn",error);156.return 1;157.158.159.vib_dev_class = class_create (THIS_MODULE,"vib-dev");160.if (IS_ERR(vib_dev_class) 161.res = PTR_ERR(vib_dev_class);162.goto out_un

20、reg_class;163.164.return 0;165.#endif166.out_unreg_class:167.class_destroy(vib_dev_class);168.return 1;169.170.171.staticint _init S3C6410_VIB_init(void )172.173.int ret = -ENODEV;174./?oey175.printk(KERN_ERR"Auly: S3C6410_VIB_init-n");176.ret = GPIO_VIB_CTL_init();177.if (ret)178.179.prin

21、tk(KERN_ERR"Auly: S3C6410_VIB_init-Fail !n");180.return ret;181.182.return 0;183.184.staticvoid _exit cleanup_GPIO_VIB(void )185.186./?uee±?187./ devfs_unregister_chrdev(Viberator_MAJOR,"gpio_vib_ctl");188.#if 0189.cdev_del(cdev_p);190.unregister_chrdev_region(dev, DEVCOUNT)

22、;191.class_destroy(vib_dev_class);192.#endif193.device_destroy(vib_dev_class, MKDEV(Viberator_MAJOR, 0);194.class_destroy(vib_dev_class);195.unregister_chrdev(Viberator_MAJOR,"viberator");196.197.MODULE_LICENSE( "GPL");198.MODULE_DESCRIPTION( "Peter first driver");199.M

23、ODULE_ALIAS_CHARDEV(Viberator_MAJOR, 0);200.201.module_init(S3C6410_VIB_init);202.module_exit(cleanup_GPIO_VIB);leddriver.h 文件1.* f_ops);ssize_t GPIO_VIB_read(struct file * file,char * buf,size_t count,loff_t2.ssize_t GPIO_VIB_write (struct file * file,const char* buf, size_tcount,loff_t * f_ops);3.

24、staticintGPIO_VIB_ioctl(struct inode*inode,structfile*file,unsignedint cmd,unsignedlong arg);4.ssize_t GPIO_VIB_open(struct inode * inode,struct file *file);5.ssize_t GPIO_VIB_release(structinode *inode,structfile * file);6.staticintGPIO_VIB_CTL_init(void );1.config LEDTEST2.tristate"LED test f

25、or ARMeasy"3.defaultn4.help5.this is a LED driverfor ARMEASY with S3C6410Makefile 文件Kconfig 文件obj-$(CONFIG_LEDTEST)+=leddriver.o1.3、在內(nèi)核配置里菜單里加入本驅(qū)動的配置項達到的效果是，可以通過內(nèi)核配置來選擇是否把本驅(qū)動編譯進內(nèi)核里，也就是出現(xiàn)在makemenuconfig 后出來的界面里，可以參考9.8章雜門droid添加新驅(qū)動方法1) 在 arch/arm/Kconfig 文件里 menu "Device Drivers" 與 end

26、menu 之間添加1.source "drivers/ledtest/Kconfig"2) 在 drivers/Kconfig menu "Device Drivers"和 endmenu 之間添加1.source "drivers/ledtest/Kconfig"3) 修改 /drivers/Makefile 文件1.Obj-$(CONFIG_LEDTEST) +=ledtest/4、編譯驅(qū)動在kernel目錄下，終端輸入1. #make menuconfig“ Device Drivers ” 下面會看到 "LED te

27、st for ARMeasy"，選擇它，1.#make保存并退出這樣，就會在/drivers/ledtest 目錄下得到leddrivr.ko 文件，它就是驅(qū)動目標文件，已 級編譯進了 zlmage里了，只要用這個kernel燒錄到開發(fā)板，開機就會自動加載本驅(qū)動，PS如果發(fā)現(xiàn)如上編譯，沒有在 ledtest目錄下生成leddriver.ko 文件，也就是本根沒有 去編譯本驅(qū)動，那就把 ledtest目錄入到/drivers/misc 目錄下，相應的修改 misc下面， 然后，在makefile里，不用選直接寫成 obj-y += leddriver.o ，這樣強制的包含進去編譯。三、

28、應用程序(測試驅(qū)動)用C語言寫一個應用，測試上面寫的驅(qū)動是否工作正常，這是一般的驅(qū)動開發(fā)流程主要有兩個文件：An droid .mk和ledtest.c1、在$(YOUR_Android )/external/LEDTEST/ 目錄編寫 ledtest.c 文件，ledtest.c1.#include<stdio.h>2.#include<stdlib.h>3.#include<fcntl.h>/ contact the open(),close(),read(),write() and soon!4.#defineDEVICE_NAME "/de

29、v/vib"/device point5.#defineLED_ON 0x116.#defineLED_OFF 0 main(int argc, char *argv)8.9.intfd;10.intret;11.char*i;12.printf("n start gpio_led_driver test rn");13.fd = open(DEVICE_NAME,O_RDWR);/Open device ,get the handle14.printf("fd = %d n",fd);15.if (fd = -1)/open

30、fail16.17.printf("open device %s error n",DEVICE_NAME);18.19.else20.21.while (1)22.23.ioctl(fd, LED_OFF);/call the output function to off LEDs24.sleep(1);/wait 1 second25.ioctl(fd, LED_ON);26.sleep(1);27.28.ret = close(fd);/close device29.printf("ret = %d n",ret);30.printf("

31、close gpio_led test n"31.32.return 0;33.2、在 $(YOUR_A ndroid "external/LEDTEST / 目錄編寫 An droid.mk 文件。這是 An droidMakefile的標準命名，不要更改。Android.mk文件的格式和內(nèi)容可以參考其他已有的Android.mk文件的寫法，針對 helloworld 程序的Android.mk文件內(nèi)容如下：1.2. LOCAL_PATH:= $(call my-dir)3. include $(CLEAR_VARS)4. LOCAL_SRC_FILES:= par he

32、llo.c5. LOCAL_MODULE := ledtestapp6. include $(BUILD_EXECUTABLE)注意上面LOCAL_SRC_FILE用來指定源文件;LOCAL_MODULE定要編譯的模塊的名字，下一步驟編譯時就要用到;include $(BUILD_EXECUTABLE)表示要編譯成一個可執(zhí)行文件，如果想編譯成動態(tài)庫則可用 BUILD_SHARED_LIBRARY這些可以在$(YOUR_Android )/build/core/config.mk查至嘰3、回到An droid源代碼頂層目錄進行編譯:# cd $(YOUR_ Android ) &&

33、; make ledtestapp例如我這里的實際操作是#cd An droid 2.1 #make ledtestapp注意 make ledtestapp 中的目標名 ledtestapp 就是上面 Android .mk文件中由 LOCAL_MODULE指定的模塊名。編譯結(jié)果如下make ledtestappPLATFORM_VERSION_CODENAME=REL PLATF0RM_VERSI0N=2.1-update1 TARGET_PRODUCT=ge neric TARGET_BUILD_VARIANT=e ng TARGET_SIMULATOR=TARGET_BUILD_TYPE=release TARGET_ARCH=armHOST_ARCH=x86 HOST_OS=li nux HOST