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
#include <linux/kernel.h> #include <linux/sched.h> #include <linux/timer.h> #include <linux/init.h> /* For __init/__exit/... */ #include <linux/module.h> #include <mach/hardware.h> #include <asm/io.h> #include <asm/uaccess.h> #include <plat/gpio-cfg.h> #include <plat/regs-clock.h> #include <plat/regs-lcd.h> #include <plat/regs-gpio.h> #include <mach/map.h> #include <linux/gpio.h> #include <plat/gpio-bank-m.h> #include <linux/cdev.h> #include <linux/fs.h> //for register_chrdev() #include <linux/device.h> #include <mach/map.h> #include "leddriver.h" #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV (WATCHDOG_MINOR) */ #include <linux/watchdog.h> /* For the watchdog specific items */ #include <linux/fs.h> /* For file operations */ #define Viberator_MAJOR 97 //?÷éè±?o? #define SCULL_NR_DEVS 4 #define SCULL_QUANTUM 4000 #define SCULL_QSET 1000 //---do as the GIO driver #define DEVCOUNT 4 #define GIO_MINOR 2 /* GIO minor no. */ static dev_t dev; //éê ?? μ?μ??÷ éè±? o? static struct cdev *cdev_p; static int openCnt; //--è???±?á?------------ int VIB_major = 97;//we asigment it for test int VIB_minor = 0; int VIB_nr_devs = SCULL_NR_DEVS; int VIB_quantum = SCULL_QUANTUM; int VIB_qset = SCULL_QSET; static struct class *vib_dev_class; #define GPNCON S3C64XX_GPNCON #define GPNDAT S3C64XX_GPNDAT #define GPNPUD S3C64XX_GPNPUD #define GPMCON S3C64XX_GPMCON #define GPMDAT S3C64XX_GPMDAT #define GPMPUD S3C64XX_GPMPUD #define VIB_ON 0x11 #defineVIB_OFF 0x22 static const struct file_operations GPIO_Viberator_ctl_ops={ .owner = THIS_MODULE, .open = GPIO_VIB_open, .read =GPIO_VIB_read, .write =GPIO_VIB_write, .ioctl = GPIO_VIB_ioctl, .release =GPIO_VIB_release, }; ssize_t GPIO_VIB_read(struct file * file,char * buf,size_t count,loff_t * f_ops) { printk(" GPIO_VIB_read \r\n"); gpio_direction_output(S3C64XX_GPM(3), 0);// return count ; } ssize_t GPIO_VIB_write (struct file * file,const char * buf, size_t count,loff_t * f_ops) { printk(" GPIO_VIB_write \r\n"); gpio_direction_output(S3C64XX_GPM(3), 1);// return count; } //ssize_t GPIO_VIB_ioctl(struct inode * inode,struct file * file,unsigned int cmd, long data) static int GPIO_VIB_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { printk(KERN_ERR"VIB:GPIO_VIB_ioctl --CMD=%x \n",cmd); switch(cmd) { case VIB_ON: gpio_direction_output(S3C64XX_GPM(1), 0);// gpio_direction_output(S3C64XX_GPM(2), 0);// gpio_direction_output(S3C64XX_GPM(3), 0);// gpio_direction_output(S3C64XX_GPM(4), 1);// printk(KERN_ERR"VIB:GPIO_VIB_ioctl --VIB_ON\n"); break; case VIB_OFF: { printk(KERN_ERR"VIB:GPIO_VIB_ioctl --VIB_OFF\n"); gpio_direction_output(S3C64XX_GPM(1), 1);// gpio_direction_output(S3C64XX_GPM(2), 1);// gpio_direction_output(S3C64XX_GPM(3), 1);// gpio_direction_output(S3C64XX_GPM(4), 0);// break; } default:break; } //gpio_free(S3C64XX_GPN(7)); } ssize_t GPIO_VIB_open(struct inode * inode,struct file * file) { //?￡?éêy //MOD_INC_USE_COUNT; printk("GPIO_VIB_open() \n"); return 0; } ssize_t GPIO_VIB_release(struct inode * inode, struct file * file) { // MOD_DEC_USE_COUNT;//?￡?éêy?? printk("GPIO_VIB_release() \n"); return 0; } static int GPIO_VIB_CTL_init(void) { int ret = -ENODEV; int error ; printk("---------------------------------------------- \r\n"); //3?ê??ˉ???ú s3c_gpio_cfgpin(S3C64XX_GPM(1), S3C_GPIO_SFN(1));//GPM1 output s3c_gpio_cfgpin(S3C64XX_GPM(2), S3C_GPIO_SFN(1));//GPM2 output s3c_gpio_cfgpin(S3C64XX_GPM(3), S3C_GPIO_SFN(1));//GPM3 output s3c_gpio_cfgpin(S3C64XX_GPM(4), S3C_GPIO_SFN(1));//GPM4 output #if 1 /*?2ì?·?ê?×￠2á?y?ˉ*/ ret = register_chrdev(Viberator_MAJOR, "viberator", &GPIO_Viberator_ctl_ops); if (ret < 0) { printk(KERN_ERR "VIB: unable to get major %d\n", ret); return ret; } //′′?¨\uc1class vib_dev_class = class_create(THIS_MODULE, "viberator"); if (IS_ERR(vib_dev_class)) { unregister_chrdev(Viberator_MAJOR, "capi20"); return PTR_ERR(vib_dev_class); } //′′?¨?úμ?￡? device_create(vib_dev_class, NULL, MKDEV(Viberator_MAJOR, 0), NULL, "vib"); // create a point under /dev/class/vib //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?￡ return 0; #endif #if 0/* ×￠2á?ˉì?*/ if ((error = alloc_chrdev_region(&dev, 0, DEVCOUNT, "vibrate")) < 0) { printk(KERN_ERR "VIB: Couldn't alloc_chrdev_region, error=%d\n", error); return 1; } printk("dev = %d \n",dev); cdev_p = cdev_alloc(); cdev_p->ops = &GPIO_Viberator_ctl_ops; error = cdev_add(cdev_p, dev, DEVCOUNT); if (error) { printk(KERN_ERR "VIB: Couldn't cdev_add, error=%d\n", error); return 1; } vib_dev_class = class_create(THIS_MODULE, "vib-dev"); if (IS_ERR(vib_dev_class)) { res = PTR_ERR(vib_dev_class); goto out_unreg_class; } return 0; #endif out_unreg_class: class_destroy(vib_dev_class); return 1; } static int __init S3C6410_VIB_init(void) { int ret = -ENODEV; //μ÷ó?oˉêy printk(KERN_ERR "Auly: S3C6410_VIB_init---\n"); ret = GPIO_VIB_CTL_init(); if(ret) { printk(KERN_ERR "Auly: S3C6410_VIB_init--Fail !!!\n"); return ret; } return 0; } static void __exit cleanup_GPIO_VIB(void) { //×￠?úéè±? // devfs_unregister_chrdev(Viberator_MAJOR,"gpio_vib_ctl"); #if 0 cdev_del(cdev_p); unregister_chrdev_region(dev, DEVCOUNT); class_destroy(vib_dev_class); #endif device_destroy(vib_dev_class, MKDEV(Viberator_MAJOR, 0)); class_destroy(vib_dev_class); unregister_chrdev(Viberator_MAJOR, "viberator"); } MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Peter first driver"); MODULE_ALIAS_CHARDEV(Viberator_MAJOR, 0); module_init(S3C6410_VIB_init); module_exit(cleanup_GPIO_VIB);
