2019-11-29(openwrt系统驱动开发B)

在/package/kernel目录下新建一个目录mydrv，下面有一个Makefile和一个src目录

在src目下下有三个文件，Kconfig，Makefile，mydrv.c

下面分别介绍每一个文件

1. 第一个Makefile

include $(TOPDIR)/rules.mk

include $(INCLUDE_DIR)/kernel.mk

PKG_NAME:=mydrv

PKG_RELEASE:=1

include $(INCLUDE_DIR)/package.mk

define KernelPackage/mydrv

SUBMENU:=Other modules

TITLE:=mydrv

FILES:=$(PKG_BUILD_DIR)/mydrv.ko

KCONFIG:=

endef

define KernelPackage/mydrv/description

This is a mydrv drivers

endef

MAKE_OPTS:= \

ARCH="$(LINUX_KARCH)" \

CROSS_COMPILE="$(TARGET_CROSS)" \

SUBDIRS="$(PKG_BUILD_DIR)"

define Build/Prepare

mkdir -p $(PKG_BUILD_DIR)

$(CP) ./src/* $(PKG_BUILD_DIR)/

endef

define Build/Compile

$(MAKE) -C "$(LINUX_DIR)" \

$(MAKE_OPTS) modules

endef

$(eval $(call KernelPackage,mydrv))

2. src下的Kconfig

config MYDRV

tristate "Just a mydrv"

help

This is a example, for debugging kernel model.

If unsure, say N.

3. src下的Makefile

obj-m += mydrv.o

4. src下的源码文件mydrv.c

/*****************************

* 驱动程序模板

* 版本：V1

* 使用方法(末行模式下)：

* :%s/mydrv/"你的驱动名称"/g

*******************************/

#include

#define MYLEDS_LED1_ON 0

#define MYLEDS_LED1_OFF 1

volatile unsigned long *GPIOMODE;

volatile unsigned long *GPIO11_DIR;

volatile unsigned long *GPIO11_SETDATA;

volatile unsigned long *GPIO11_RESETDATA;

/**************** 基本定义 **********************/

//内核空间缓冲区定义

#if 0

#define KB_MAX_SIZE 20

#define kbuf[KB_MAX_SIZE];

#endif

//加密函数参数内容： _IOW(IOW_CHAR , IOW_NUMn , IOW_TYPE)

//加密函数用于mydrv_ioctl函数中

//使用举例：ioctl(fd , _IOW('L',0x80,long) , 0x1);

//#define NUMn mydrv , if you need!

#define IOW_CHAR 'L'

#define IOW_TYPE long

#define IOW_NUM1 0x80

//初始化函数必要资源定义

//用于初始化函数当中

//device number;

dev_t dev_num;

//struct dev

struct cdev mydrv_cdev;

//auto "mknode /dev/mydrv c dev_num minor_num"

struct class *mydrv_class = NULL;

struct device *mydrv_device = NULL;

/**************** 结构体 file_operations 成员函数 *****************/

/*======================================================================

======================================================================*/

//open

static int mydrv_open(struct inode *inode, struct file *file)

{

printk("mydrv drive open...\n");

*GPIO11_RESETDATA |=(1u<<11);

return 0;

}

/*======================================================================

======================================================================*/

//close

static int mydrv_close(struct inode *inode , struct file *file)

{

printk("mydrv drive close...\n");

return 0;

}

/*======================================================================

======================================================================*/

//read

static ssize_t mydrv_read(struct file *file, char __user *buffer,

size_t len, loff_t *pos)

{

int ret_v = 0;

printk("mydrv drive read...\n");

return ret_v;

}

/*======================================================================

======================================================================*/

//write

static ssize_t mydrv_write( struct file *file , const char __user *buffer,

size_t len , loff_t *offset )

{

int ret_v = 0;

printk("mydrv drive write...\n");

return ret_v;

}

/*======================================================================

======================================================================*/

//unlocked_ioctl

static int mydrv_ioctl (struct file *filp , unsigned int cmd , unsigned long arg)

{

int ret_v = 0;

printk("mydrv drive ioctl...\n");

switch(cmd)

{

//常规：

//cmd值自行进行修改

case MYLEDS_LED1_ON:

*GPIO11_RESETDATA |= (1u<<11);

break;

case MYLEDS_LED1_OFF:

*GPIO11_SETDATA |= (1u<<11);

break;

//带密码保护：

//请在"基本定义"进行必要的定义

case _IOW(IOW_CHAR,IOW_NUM1,IOW_TYPE):

{

if(arg == 0x1) //第二条件

{

}

break;

default:

break;

}

return ret_v;

}

/***************** 结构体： file_operations ************************/

/*======================================================================

//struct

======================================================================*/

static const struct file_operations mydrv_fops = {

.owner = THIS_MODULE,

.open = mydrv_open,

.release = mydrv_close,

.read = mydrv_read,

.write = mydrv_write,

.unlocked_ioctl = mydrv_ioctl,

};

/************* functions: init , exit*******************/

//条件值变量，用于指示资源是否正常使用

unsigned char init_flag = 0;

unsigned char add_code_flag = 0;

/*======================================================================

//init

======================================================================*/

static __init int mydrv_init(void)

{

int ret_v = 0;

printk("mydrv drive init...\n");

//函数alloc_chrdev_region主要参数说明：

//参数2：次设备号

//参数3：创建多少个设备

if( ( ret_v = alloc_chrdev_region(&dev_num,0,1,"mydrv") ) < 0 )

{

goto dev_reg_error;

}

init_flag = 1; //标示设备创建成功；

printk("The drive info of mydrv:\nmajor: %d\nminor: %d\n",

MAJOR(dev_num),MINOR(dev_num));

cdev_init(&mydrv_cdev,&mydrv_fops);

if( (ret_v = cdev_add(&mydrv_cdev,dev_num,1)) != 0 )

{

goto cdev_add_error;

}

mydrv_class = class_create(THIS_MODULE,"mydrv");

if( IS_ERR(mydrv_class) )

{

goto class_c_error;

}

mydrv_device = device_create(mydrv_class,NULL,dev_num,NULL,"mydrv");

if( IS_ERR(mydrv_device) )

{

goto device_c_error;

}

printk("auto mknod success!\n");

//------------ 请在此添加您的初始化程序 --------------//

//GPIOMODE=(volatile unsigned long *)ioremap(0x10000060,4);//gpio 复用时需要配置

GPIO11_DIR=(volatile unsigned long *)ioremap(0x10000600,4);

GPIO11_SETDATA=(volatile unsigned long *)ioremap(0x10000630,4);

GPIO11_RESETDATA=(volatile unsigned long *)ioremap(0x10000640,4);

//*GPIOMODE |= (1u<<11);

*GPIO11_DIR |= (1u<<11);

//如果需要做错误处理，请：goto mydrv_error;

add_code_flag = 1;

//---------------------- END ---------------------------//

goto init_success;

dev_reg_error:

printk("alloc_chrdev_region failed\n");

return ret_v;

cdev_add_error:

printk("cdev_add failed\n");

unregister_chrdev_region(dev_num, 1);

init_flag = 0;

return ret_v;

class_c_error:

printk("class_create failed\n");

cdev_del(&mydrv_cdev);

unregister_chrdev_region(dev_num, 1);

init_flag = 0;

return PTR_ERR(mydrv_class);

device_c_error:

printk("device_create failed\n");

cdev_del(&mydrv_cdev);

unregister_chrdev_region(dev_num, 1);

class_destroy(mydrv_class);

init_flag = 0;

return PTR_ERR(mydrv_device);

//------------------ 请在此添加您的错误处理内容 ----------------//

mydrv_error:

printk("mydrv drive close...\n");

add_code_flag = 0;

return -1;

//-------------------- END -------------------//

init_success:

printk("mydrv init success!\n");

return 0;

}

/*======================================================================

//exit

======================================================================*/

static __exit void mydrv_exit(void)

{

printk("mydrv drive exit...\n");

if(add_code_flag == 1)

{

//---------- 请在这里释放您的程序占有的资源 ---------//

printk("free your resources...\n");

//iounmap(GPIOMODE);

iounmap(GPIO11_DIR);

iounmap(GPIO11_SETDATA);

iounmap(GPIO11_RESETDATA);

printk("free finish\n");

//---------------------- END -------------------//

}

if(init_flag == 1)

{

//释放初始化使用到的资源;

cdev_del(&mydrv_cdev);

unregister_chrdev_region(dev_num, 1);

device_unregister(mydrv_device);

class_destroy(mydrv_class);

}

/**************** module operations**********************/

//module loading

module_init(mydrv_init);

module_exit(mydrv_exit);

//some infomation

MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("from Jafy");

MODULE_DESCRIPTION("mydrv drive");

/********************* The End ***************************/

make menuconfig 下kernel 选择Other ，选择mydrv

保存，

make package/kernel/mydrv/compile V=s

或者直接

make -j1 V=s 编译，然后把mydrv.ko 文件copy到开发板/tmp目录下，运行

insmod mydrv.ko

显示驱动注册成功，类注册成功

可以在/dev 以及/sys/class 目录下查看

————————————————

原文链接：https://blog.csdn.net/cym_anhui/article/details/87915841

2019-11-29(openwrt系统驱动开发B)

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