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

驱动修改的文件.rar (9.7 KB)

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