20130801 linux添加驱动 在dev下可以看到

友善之臂的Tiny210 linux3.0.8 for android

实现：在linux内核下添加LED的驱动 LED@LZM@FJICC并且可以在# /dev/下看到。

#ls /dev/看到驱动LED@LZM@FJICC

1.进入linux/drivers/char/新建一个文件lzm_fjicc.c

编写内容：

//lzm_fjicc.c

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/miscdevice.h>

#include <linux/fs.h>

#include <linux/types.h>

#include <linux/moduleparam.h>

#include <linux/slab.h>

#include <linux/ioctl.h>

#include <linux/cdev.h>

#include <linux/delay.h>

#include <mach/gpio.h>

#include <mach/regs-gpio.h>

#include <plat/gpio-cfg.h>

 

#define DEVICE_NAME "LED@LZM@FJICC"

static int led_gpios[] = {

S5PV210_GPJ2(0),

S5PV210_GPJ2(1),

S5PV210_GPJ2(2),

S5PV210_GPJ2(3),

};

 

#define LED_NUMARRAY_SIZE(led_gpios)

 

 

static long fjicc_leds_ioctl(struct file *filp, unsigned int cmd,

unsigned long arg)

{

switch(cmd) {

case 0:

case 1:

if (arg > LED_NUM) {

return -EINVAL;

}

 

gpio_set_value(led_gpios[arg], !cmd);

//printk(DEVICE_NAME": %d %d\n", arg, cmd);

break;

 

default:

return -EINVAL;

}

 

return 0;

}

 

static struct file_operations fjicc_led_dev_fops = {

.owner= THIS_MODULE,

.unlocked_ioctl= fjicc_leds_ioctl,

};

 

static struct miscdevice fjicc_led_dev = {

.minor= MISC_DYNAMIC_MINOR,

.name= DEVICE_NAME,

.fops= &fjicc_led_dev_fops,

};

 

static int __init fjicc_led_dev_init(void) {

int ret;

int i;

 

for (i = 0; i < LED_NUM; i++) {

ret = gpio_request(led_gpios[i], "LED");

if (ret) {

printk("%s: request GPIO %d for LED failed, ret = %d\n", DEVICE_NAME,

led_gpios[i], ret);

return ret;

}

 

s3c_gpio_cfgpin(led_gpios[i], S3C_GPIO_OUTPUT);

gpio_set_value(led_gpios[i], 1);

}

 

ret = misc_register(&fjicc_led_dev);

 

printk(DEVICE_NAME"\tinitialized\n");

 

return ret;

}

 

static void __exit fjicc_led_dev_exit(void) {

int i;

 

for (i = 0; i < LED_NUM; i++) {

gpio_free(led_gpios[i]);

}

 

misc_deregister(&fjicc_led_dev);

}

 

module_init(fjicc_led_dev_init);

module_exit(fjicc_led_dev_exit);

 

MODULE_LICENSE("GPL");

MODULE_AUTHOR("LZM@FJICC");

 

2.然后修改char目录下的Kconfig和Makefile文件：

Kconfig:

config LEDS_LZM_FJICC

tristate "LEDS_LZM_FJICC"

depends on MACH_MINI210

default y

help

This option enables support for LEDs connected to GPIO lines

on Mini210 boards.

 

Makefile:

obj-$(CONFIG_LEDS_LZM_FJICC)+= lzm_fjicc.o

 

3.进到linux根目录，然后#make menuconfig

就可以在配置菜单中看到LEDS_LZM_FJICC,具体在devices driversàchracter devicesà就可以看到了。

4.配置好了，make zImage就可以了。

5.烧写了系统后，就可以查看驱动了。#ls /dev/

6.提升驱动权限：#chmod 777 /dev/LED@LZM@FJICC