喜羊羊系列【设备 - 驱动器 编译进内核】

博客：http://blog.csdn.net/muyang_ren

这篇和设备-驱动动态载入进内核做对照

*针对不同的平台。可能放进的不是以下的文件内，仅仅做參考

1、头文件

放进：linux-3.0.8\arch\arm\plat-samsung\include\plat

led.h

#ifndef _HEAD_H
#define _HEAD_H

#define MAGIC 'h'

#define LED_ON 		_IOW(MAGIC,1,int)
#define LED_OFF 	_IOW(MAGIC,0,int)

struct led_device{
 	dev_t 			devno;
	unsigned int 	led_major;
	struct cdev	 	*led_cdev;
	struct class 	*led_class;
	struct device 	*led_device;
};
#endif

====================================================================================================================================

2、设备文件

方法一：将设备资源直接加进/linux-3.0.8/arch/arm/mach-s5pv210下的mach-smdkv210.c

①                                              
struct platform_device s5pv210_led_device_lhy = {
	.name			= 	"s5pv210_led_lhy",
	.id			= 	1,
};

static struct platform_device *smdkv210_devices[] __initdata = {
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}

②将设备信息加入总线
<span style="white-space:pre">	</span>改动arch/arm/mach-s5pv210/mach-smdkv210.c文件
		static struct platform_device *smdkv210_devices[] __initdata = {
			...
			...
			/*加入例如以下代码*/
			&s5pv210_led_device_lhy,    //新加入的
		}

方法二：

①将设备文件dev-led.c 放进 linux-3.0.8/arch/arm/plat-samsung

led_dev.c 

#include <linux/platform_device.h>
#include <plat/led.h>
#include <plat/devs.h>
#include <plat/cpu.h>

struct platform_device s5pv210_led_device_lhy = {
	.name			= 	"s5pv210_led_lhy",
	.id				= 	1,
};

②向arch/arm/mach-s5pv210/mach-smdkv210.c(跟平台架构相关文件)加入

static struct platform_device *smdkv210_devices[] __initdata = {
	....
	&s5pv210_led_device_lhy,     //新加入
};

③向linux-3.0.8/arch/arm/plat-samsung/Makefile加入

	obj-$(CONFIG_S3C_DEV_LED)       += led_dev.o

④向linux-3.0.8/arch/arm/plat-samsung/Kconfig加入

	config S3C_DEV_LED
        bool "S5PV210 LED  driver support"
        help
             s5pv210 led device support

⑤加入外部声明arch/arm/plat-samsung/include/plat/devs.h

	extern struct platform_device s5pv210_led_device_lhy;

====================================================================================================================================

3、平台驱动

①将led_drv.c 放进linux-3.0.8/drivers/my_led

led_drv.c 

#include<linux/fs.h>		//register_chrled
#include<linux/device.h>	//class_create/ledice_create
#include<linux/slab.h>		//kmalloc
#include<asm/uaccess.h>		//copy_to_user/copy_from_user
#include<asm/io.h>			//ioremap
#include<linux/gpio.h>		//gpio_request
#include <plat/gpio-cfg.h>	//s3c_gpio_cfgpin
#include <linux/cdev.h>     //cdev_alloc
#include <linux/platform_device.h>

//下面是移植时须要添加的
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <plat/cpu.h>
#include <plat/led.h>
#include <plat/devs.h>

static struct led_device *led_drv;

static int led_open(struct inode *inode, struct file *file)
{	
	printk(KERN_INFO"%s()-%d\n", __func__, __LINE__);
	
	s3c_gpio_cfgpin(S5PV210_GPC0(3),S3C_GPIO_OUTPUT);
	s3c_gpio_cfgpin(S5PV210_GPC0(4),S3C_GPIO_OUTPUT);

	return 0;
}

static ssize_t led_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
{
	printk(KERN_INFO"%s()-%d\n", __func__, __LINE__);
	return count;
}

ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
{
	printk(KERN_INFO"%s()-%d\n", __func__, __LINE__);
	return 0;
}

static long led_ioctl(struct file *file, unsigned int cmd, unsigned long val)
{
	printk(KERN_INFO"%s()-%d\n", __func__, __LINE__);
	printk(KERN_INFO"cmd=%d arg=%ld\n", cmd, val);

	switch(cmd)
	{
		case LED_ON:
			gpio_set_value(S5PV210_GPC0(val),1);
			break;
		case LED_OFF:
			gpio_set_value(S5PV210_GPC0(val),0);
			break;
		default:
			break;
	}
	return 0;
}


//硬件操作方法
static struct file_operations led_fops={
		.owner	= THIS_MODULE,	
		.open   = led_open,
		.write  = led_write,
		.read   = led_read,
		.unlocked_ioctl = led_ioctl,
};



static int s5pv210_led_probe(struct platform_device *pdrv){
	int ret;
	led_drv = kmalloc(sizeof(struct led_device),GFP_KERNEL);
	if(led_drv==NULL){
		printk(KERN_ERR"no memory malloc for fs210_led\n");
		return -ENOMEM;
	}

	/*1. 动态注冊/申请主设备*/
	ret=alloc_chrdev_region(&led_drv->devno,0,1,"dev_module");
	if (ret < 0) {
		printk(KERN_ERR "unable to get major\n");
		return -EFAULT;
		goto out_err_1;
	}	
	
	//从设备号中分离出主设备号
	led_drv->led_major = MAJOR(led_drv->devno);
	/*为cdev分配空间*/
	led_drv->led_cdev  = cdev_alloc();
	/*注冊硬件操作方法/初始化cdev*/
	cdev_init(led_drv->led_cdev,&led_fops);
	/*注冊字符设备*/
	cdev_add(led_drv->led_cdev,led_drv->devno,1);


	/*2. 创建设备类*/
	led_drv->led_class=class_create(THIS_MODULE,"led_class");
	if (IS_ERR(led_drv->led_class)) {
		printk(KERN_ERR "class_create() failed for led_class\n");
		ret = -ENODATA;
		goto out_err_2;
	}


	/*3. 创建设备文件*/
	led_drv->led_device=device_create(led_drv->led_class,NULL,MKDEV(led_drv->led_major,0),NULL,"led"); //   /led/xxx
	if (IS_ERR(led_drv->led_device)) {
		printk(KERN_ERR "device_create failed for led_device\n");
		ret = -ENODEV;
		goto out_err_3;
	}
	

	/*申请GPC0_3，4引脚资源*/
	gpio_request(S5PV210_GPC0(3),"LED1");
	gpio_request(S5PV210_GPC0(4),"LED2");


	return 0;
out_err_3:
	class_destroy(led_drv->led_class);
out_err_2:
	unregister_chrdev(led_drv->led_major,"led_module");
out_err_1:
	kfree(led_drv);
	return ret;

}
static int s5pv210_led_remove(struct platform_device *pdrv){
	unregister_chrdev(led_drv->led_major,"led_module");
	device_destroy(led_drv->led_class,MKDEV(led_drv->led_major,0));
	class_destroy(led_drv->led_class);
	gpio_free(S5PV210_GPC0(3));
	gpio_free(S5PV210_GPC0(4));
	kfree(led_drv);
	return 0;
}


struct platform_device_id led_ids[]={
	[0]={
		.name = "s5pv210_led_lhy",
		.driver_data = 0,
	},
};

static struct platform_driver s5pv210_led_driver = {
	.probe	= s5pv210_led_probe,
	.remove = s5pv210_led_remove,
	.driver = {		.name = "s5pv210_led_lhy",
		.owner = THIS_MODULE,	},
	.id_table = led_ids,
}; 

static int __devinit s5pv210_led_init(void)
{
	return platform_driver_register(&s5pv210_led_driver);
}

static void __devexit s5pv210_led_exit(void)
{
	platform_driver_unregister(&s5pv210_led_driver);
}

module_init(s5pv210_led_init);
module_exit(s5pv210_led_exit);

MODULE_DESCRIPTION("LED driver for Marvell PM860x");
MODULE_AUTHOR("kiron");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s5pv210-led");

②在当前文件夹的Kconfig后加入，没有就新建

	config S5PV210_LED_DRV
    		tristate  "led_dev  for fs210 device"
    		help
        		led driver is for s5pv210, choose y/m/n

③在当前文件夹的Makefile后加入，没有就新建

<span style="white-space:pre">	</span>obj-$(CONFIG_S5PV210_LED_DRV) = led_drv.o

④改动上级文件夹的Makefile和Kconfig

将linux-3.0.8/drivers/Kconfig  加入

	source "drivers/my_led/Kconfig"

将linux-3.0.8/drivers/Makefile 加入

<span style="white-space:pre">	</span>obj-y        += mydriver/

最后就是自己make menuconfig里配置选项了。
====================================================================================================================================

4、測试程序

编译測试要使用交叉工具连

<span style="white-space:pre">	</span>arm-none-linux-gnueabi-gcc led_test.c -o led_test

附：

将可运行文件增加到开机启动，改动根文件系统filesystem

vi  filesystem/etc/init.d/rcS
./star_app/led_test

測试程序

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <unistd.h>

#define MAGIC 'h'
#define LED_ON 		_IOW(MAGIC,1,int)
#define LED_OFF 	_IOW(MAGIC,0,int)

static void my_sleep(int n){
	int j;
	for(j=0; j<10000000*n; j++);
}

int main(void)
{
	printf("-------------------------------\n"
	<span style="white-space:pre">	</span>"||   start:一闪一闪亮晶晶    ||\n"
		"-------------------------------\n");
	my_sleep(1);

	int fd;
	unsigned int cmd=0;
	unsigned long val=0;
	
	fd=open("/dev/led", O_RDWR);
	if(fd<0){
		perror("open failed!\n");
		exit(1);
	}

	int i;
	for(i=0; i<10; i++){
		if(i%2==0)
			cmd=LED_OFF;
		else
			cmd=LED_ON;
		
		val=3;            //亮 led3
		if(ioctl(fd,cmd,val)<0){
			perror("ioctl failed!\n");
			exit(1);
		}
		
		val=4;            //亮 led4
		if(ioctl(fd,cmd,val)<0){
			perror("ioctl failed!\n");
			exit(1);
		}
		my_sleep(1);
	}
	
	close(fd);
	return 0;
}