TQ210 LED驱动及测试
1. 编写led驱动
1.1 在系统中创建目录/home/share/led/
#mkdir –p /home/share/led
进入led目录
#cd /home/share/led
1.2创建源码文件led_driver.c
#vim led_driver.c
源码内容见附件一。
保存退出.
1.3创建并编辑Makefile
在该目录下创建Makefile文件，将驱动程序编译成模块。
#vim Makefile
内容如下：
oj-m +=led_driver.o
CURRENT_PATH := /home/share/led
LINUX_KERNEL ?= /home/share/learning/linux-2.6.35
#LINUX_KERNEL_PATH := $(LINUX_KERNEL)

default:
$(MAKE) -C $(LINUX_KERNEL) m=$(CURRENT_PATH) modules
clean:
$(MAKE) -C $(LINUX_KERNEL) M=$(CURRENT_PATH) clean
2. 编译
TQ210使用天嵌提供交叉编译器，路径：/home/share/tmp/opt/EmbedSky/4.4.6/bin
在该目录下直接make即可
#make

3. 测试led驱动
测试代码：见附件二

使用交叉编译工具编译程序：
# arm-linux-gcc -o led_test led_test.c
将生成的可执行程序led_test复制到nfs文件系统/home/share/nfsboot/rootfs中/mnt目录下；
在超级终端上控制开发板。
挂载好nfs文件系统：
#mount –t nfs 10.10.84.41:/home/share/nfsboot/rootfs –o nolock /mnt
进入挂载在/mnt 目录下的nfs文件系统内并且进入内部/mnt目录下：
#cd /mnt //此目录是开发版的子目录
#cd /mnt //此目录是挂载的宿主机上的nfs文件系统的子目录
执行可执行文件：
# ./led_test
出现段错误提示，原因参数不正确，还需要输入led的序号，以及开关指令。测试程序没有做好参数检查，所以会段错误在代码中对argc进行判断即可。
#./led_test 2 on //打开第二个led
#./led_test 2 off //关掉第二个led
开发板上两个LED灯均能正确控制，至此led驱动及测试代码试验完成。

附件一led驱动源码
/***********************************************************************************
* drivers/char/tq210_leds.c
* 功能简要：
* 该驱动注册一个字符设备“/dev/led”, 用于2个LED。
* 函数简介：
* static void tq210_debug_leds(unsigned int cmd,unsigned long arg),用于内核驱动调试
* 提供的外部接口：
* ioctol(struct inode *inode,struct file *file,unsigned int brightness);
* 用于LED的亮，灭。
* 调用实例：
* 提供控制台，命令式的测试程序。
*
*************************************************************************************/
#include <linux/miscdevice.h>
#include <linux/input.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/uaccess.h>

#include <mach/map.h>
#include <mach/gpio.h>
//#include <mach/gpio-bank.h>
#include <mach/regs-gpio.h>
#include <plat/gpio-core.h>
#include <plat/gpio-cfg.h>
#include <plat/gpio-cfg-helpers.h>

#define DEVICE_NAME “led”

/* 应用程序执行ioctl(fd, cmd, arg)时的第2个参数 */
/*the second parameter that application program execute*/
#define IOCTL_GPIO_ON 1
#define IOCTL_GPIO_OFF 0

/* 用来指定LED所用的GPIO引脚 */
/*appoint the pin the LED will use*/
static unsigned long gpio_table [] =
{
S5PV210_GPC0(3),
S5PV210_GPC0(4),
};

/* 用来指定GPIO引脚的功能：输出 */
/*appoint the function of the pin:out put*/
static unsigned int gpio_cfg_table [] =
{
S3C_GPIO_SFN(1),
S3C_GPIO_SFN(1),
};

//static char gpio_name[][]={{“GPC0_3”},{“GPC0_4”}};

#ifdef CONFIG_TQ210_DEBUG_LEDS
static void tq210_debug_leds(unsigned int cmd,unsigned long arg)
{
gpio_direction_output(gpio_table[arg], cmd);
//s3c_gpio_setpin(gpio_table[arg], cmd);
}
static void toggle_led(unsigned int cmd,unsigned long arg)
{
int loop=0;
printk(“%s : led %ld toggle now: \n”,__func__,arg);
for(;loop<11;loop++)
{ cmd = loop%2;
printk(“leds %d %s \n”,arg+1,(cmd)?”on”:”o ff”);
tq210_debug_leds(cmd,arg);
mdelay(1000);
}
}
#endif

/**
*函数功能：打开/dev/led设备，设备名是：/dev/led
*fuction:open /dev/led device ,devce name: /dev/led
**/
static int tq210_gpio_open(struct inode *inode, struct file *file)
{
int i;
int err;
err = gpio_request(gpio_table[0], “GPC0_3”);
if(err)
{
printk(KERN_ERR “failed to request GPC0_3 for LVDS PWDN pin\n”);
return err;
}
err = gpio_request(gpio_table[1], “GPC0_4”);
if(err)
{
printk(KERN_ERR “failed to request GPC0_4 for LVDS PWDN pin\n”);
return err;
}
printk(KERN_INFO ” leds opened\n”);
for (i = 0; i < sizeof(gpio_table)/sizeof(unsigned long); i++)
{
s3c_gpio_cfgpin(gpio_table[i], gpio_cfg_table[i]);
gpio_direction_output(gpio_table[i], 0);
//s3c_gpio_setpin(gpio_table[i], 0);
}
#ifdef CONFIG_TQ210_DEBUG_LEDS
for (i = 0; i < sizeof(gpio_table)/sizeof(unsigned long); i++)
{
toggle_led(1,i);
}
#endif
return 0;
}

/**
*函数功能：用于控制led的亮灭
*fuction:control the led /turn on & turn off
*控制字为cmd，arg为控制哪个灯的亮灭取值范围为0-1：cmd为IOCTL_GPIO_ON时亮，cmd为IOCTL_GPIO_OFF为灭
*control byte is cmd; arg appointed which led wile be turn on or off,it can be 0 and 1;IOCTL_GPIO_ON:turn on,IOCTL_GPIO_OFF:turn off.
**/
static long tq210_gpio_ioctl(
struct inode *inode,
struct file *file,
unsigned int cmd,
unsigned long arg)
{
arg -= 1;
if (arg > sizeof(gpio_table)/sizeof(unsigned long))
{
return -EINVAL;
}
switch(cmd)
{
case IOCTL_GPIO_ON:
// 设置指定引脚的输出电平为1
gpio_direction_output(gpio_table[arg], 1);
//s3c_gpio_setpin(gpio_table[arg], 1);
return 0;
case IOCTL_GPIO_OFF:
// 设置指定引脚的输出电平为0
gpio_direction_output(gpio_table[arg], 0);
//s3c_gpio_setpin(gpio_table[arg], 0);
return 0;
default:
return -EINVAL;
}
}
static int tq210_gpio_close(struct inode *inode, struct file *file)
{
gpio_free(gpio_table[0]);
gpio_free(gpio_table[1]);
printk(KERN_INFO “TQ210 LEDs driver successfully close\n”);
return 0;
}
/*驱动接口设置*/
/*setting the interface of the driver*/
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.ioctl = tq210_gpio_ioctl,
.open = tq210_gpio_open,
.release = tq210_gpio_close,
};
/*设备结构的设置*/
/*setting the architecture of the device*/
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &dev_fops,
};
/*初始化设备，配置对应的IO，以及注册设备*/
/*init the device, config the right IO and register the device*/
static int __init dev_init(void)
{
int ret;
int i;
int err;
#ifdef CONFIG_TQ210_DEBUG_LEDS
err = gpio_request(gpio_table[0], “GPC0_3”);
if(err)
{
printk(KERN_ERR “failed to request GPC0_3 for LVDS PWDN pin\n”);
return err;
}
err = gpio_request(gpio_table[1], “GPC0_4”);
if(err)
{
printk(KERN_ERR “failed to request GPC0_4 for LVDS PWDN pin\n”);
return err;
}
for (i = 0; i < sizeof(gpio_table)/sizeof(unsigned long); i++)
{
//gpio_request(gpio_table[0],gpio_name[i]);
s3c_gpio_cfgpin(gpio_table[i], gpio_cfg_table[i]);//配置管脚为输出config the pin to out put
gpio_direction_output(gpio_table[i], 0);
//s3c_gpio_setpin(gpio_table[i], 0);//设置管脚为低电平config the pin to low level
s3c_gpio_setpull(gpio_table[i], S3C_GPIO_PULL_NONE);
}
#endif
ret = misc_register(&misc);
printk(KERN_INFO “TQ210 LEDs driver successfully probed\n”);
#ifdef CONFIG_TQ210_DEBUG_LEDS
for (i = 0; i < sizeof(gpio_table)/sizeof(unsigned long); i++)
{
toggle_led(1,i);
}
#endif
return ret;
}
/*注销设备*/
/*log out the device*/
static void __exit dev_exit(void)
{
misc_deregister(&misc);
gpio_free(gpio_table[0]);
gpio_free(gpio_table[1]);
printk(KERN_INFO “TQ210 LEDs driver successfully exit\n”);
}

module_init(dev_init);
module_exit(dev_exit);

MODULE_LICENSE(“GPL”);
MODULE_AUTHOR(“www.embedsky.com”);
MODULE_DESCRIPTION(“LEDS’ Driver”);
附件二 led测试源码
/*FILENAME:led_test.c
*AUTHOR:Michael Li
*DATE:2013-06-03
*DESCRIPTION:the test of the led driver
* */
#include<stdio.h>
#include<fcntl.h>

#define DEVICENAME “/dev/led”

#define IOCTL_LED_ON 1
#define IOCTL_LED_OFF 0

int main(int argc, char **argv)
{
FILE *fd;
int led_no = 0;
fd = (FILE *)open(DEVICENAME,0);
if(argc < 3)
{
printf(“The arguments you input are wrong\n”);
printf(“USE:\n”);
printf(“\t\t./program\tled-number\ton/off\n”);
return -1;
}
//led_no = strtoul(argv[1],0,0) -1;//its wrong to set like this
led_no = strtoul(argv[1],0,0);//operate the led_1 by input 1 and led_2 by input 2
printf(“111111\n”);
if(!strcmp(argv[2],”on”))//turn on the led
{
ioctl(fd,IOCTL_LED_ON,led_no);
printf(“you want the %d on\n”,led_no);
}
else if(!strcmp(argv[2],”off”))//turn off the led
{
ioctl(fd,IOCTL_LED_OFF,led_no);
}
else printf(“error!\n”);
return 0;
}
附件三：流水灯
/*FILENAME:led_test.c
*AUTHOR:Michael Li
*DATE:2013-06-03
*DESCRIPTION:the test of the led driver,please refer to the label “usage:” below.
* */
#include<stdio.h>
#include<fcntl.h>
#include <signal.h>
//#include <time.h>
#include <sys/time.h>

#define DEVICENAME “/dev/led”

#define IOCTL_LED_ON 1
#define IOCTL_LED_OFF 0

void sigoutime();
void timer_init();
void delay(int time);

int time_1= 0;
int main(int argc, char **argv)
{
FILE *fd;
int led_no = 0;
int i = 0;
fd = (FILE *)open(DEVICENAME,0);
int delay_grade = 0;
timer_init();
usage:
if(argc < 3)
{
printf(“The arguments you input are wrong\n”);
printf(“USE:\n”);
printf(“\t./program\t<right/left/both>\t<1/2/3>\n”);
printf(“\t3:slow;2:faster;1:fastest\n”);
printf(“\teg: ./led_flow\tleft\t1\n\tlet the led light start from left and the speed is the fastest\n”);
return -1;
}

if(!strcmp(argv[2],”1″))
delay_grade = 1;//20ms
else if (!(argv[2],”2″))
delay_grade = 15;//300ms
else if(!(argv[2],”3″))
delay_grade = 50;//1s
else
delay_grade = 30;//600ms

if(!strcmp(argv[1],”left”))//turn on the led
{
for(i=0;i<40;i++)
{
if((i%2)!=0)
{
led_no = 1;
}
else
led_no = 2;
ioctl(fd,IOCTL_LED_ON,led_no);
printf(“you want the %d on\n”,led_no);
delay(delay_grade);
ioctl(fd,IOCTL_LED_OFF,led_no);
}
}
else if(!strcmp(argv[1],”right”))//turn off the led
{
for(i=0;i<20;i++)
{
if((i%2)==0)
{
led_no = 1;
}
else
led_no = 2;
ioctl(fd,IOCTL_LED_ON,led_no);
delay(delay_grade);
ioctl(fd,IOCTL_LED_OFF,led_no);
}
}
else if(!strcmp(argv[1]),”both”)
{
for(i=0;i<50;i++)
{
ioctl(fd,IOCTL_LED_ON,1);
ioctl(fd,IOCTL_LED_ON,2);
delay(delay_grade);//delay 0.8s
ioctl(fd,IOCTL_LED_OFF,1);
ioctl(fd,IOCTL_LED_OFF,2);
delay(delay_grade);//delay 0.8s
}
}
else printf(“error!\n”);
close(fd);
return 0;
}

void delay(int time)
{
while(time_1<time);
time_1 = 0; //you must clean the time_1 every time you sign a time
return;
}
void timer_init() //内核定时器初始化函数
{
struct itimerval value; //(1)定义类型为itimerval的结构体变量
signal(SIGALRM, sigoutime);//注册信号的处理函数
value.it_value.tv_sec = 0;//秒——设置第一次运行sigroutine函数时间
value.it_value.tv_usec = 100000;//微妙——设置为0
value.it_interval.tv_sec = 0;//秒——设置间隔运行sigroutine函数的时间（实际定时）
value.it_interval.tv_usec = 20000;//微妙———设置为20ms
setitimer(ITIMER_REAL, &value, NULL); //(2)设置 “真实计时器“参数
}
void sigoutime()
{
time_1++;
return;
}