板子是6410，用NFS挂载的根文件系统，可是不知道为什么终端上都没有写权限，我就把根目录和dev目录都改成777了，不知道这个有关系没。。。大家来看看
驱动程序：
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <mach/gpio.h>
#include <mach/gpio-bank-k.h>
#include <plat/gpio-cfg.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <asm/unistd.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "memdev.h"
#define DEVICE_NAME "leds"
static unsigned long led_table [] = {
S3C64XX_GPK(4),
S3C64XX_GPK(5),
S3C64XX_GPK(6),
S3C64XX_GPK(7)
};
static unsigned int led_cfg_table [] = {
S3C64XX_GPK_OUTPUT(4),
S3C64XX_GPK_OUTPUT(5),
S3C64XX_GPK_OUTPUT(6),
S3C64XX_GPK_OUTPUT(7)
};
static int sbc2440_leds_ioctl(
struct file *file,
unsigned int cmd,
unsigned long arg)
{
int i = 0;
/* 检测命令的有效性 */
if (_IOC_TYPE(cmd) != MEMDEV_IOC_MAGIC)
return -EINVAL;
if (_IOC_NR(cmd) > MEMDEV_IOC_MAXNR)
return -EINVAL;
/* 根据命令，执行相应的操作 */
switch(cmd) {
case MEMDEV_IOCOFF:
/*灯全灭*/
cmd = 1;
for(i=0; i<4; i++)
gpio_set_value(led_table
, cmd);
return 0;
case MEMDEV_IOCON:
/*灯全亮*/
for(i=0; i<4; i++)
gpio_set_value(led_table, cmd);
return 0;
default:
return -EINVAL;
}
}
/*文件操作结构体*/
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = sbc2440_leds_ioctl,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
int i;
/*设置GPIO控制寄存器，GPIO设置为输出模式,默认下灯全灭*/
for (i = 0; i < 4; i++) {
s3c_gpio_cfgpin(led_table, led_cfg_table);
gpio_set_value(led_table, 1);
}
/*注册混杂型字符设备驱动*/
ret = misc_register(&misc);
printk (DEVICE_NAME"\tinitialized\n");
return ret;
}
static void __exit dev_exit(void)
{
/*注销混杂型字符设备驱动*/
misc_deregister(&misc);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_AUTHOR("David Xie");
MODULE_LICENSE("GPL");
驱动加载后出错信息：
/ # insmod leds_misc.ko
------------[ cut here ]------------
WARNING: at fs/sysfs/dir.c:455 sysfs_add_one+0x74/0x9c()
sysfs: cannot create duplicate filename '/devices/virtual/misc/leds'
Modules linked in: leds_misc(+)
[<c003a570>] (unwind_backtrace+0x0/0xec) from [<c00498b4>] (warn_slowpath_commo)
[<c00498b4>] (warn_slowpath_common+0x4c/0x64) from [<c004994c>] (warn_slowpath_)
[<c004994c>] (warn_slowpath_fmt+0x2c/0x3c) from [<c00edd0c>] (sysfs_add_one+0x7)
one_wire_status: 2
[<c00edd0c>] (sysfs_add_one+0x74/0x9c) from [<c00ee714>] (create_dir+0x5c/0xac)
[<c00ee714>] (create_dir+0x5c/0xac) from [<c00ee828>] (sysfs_create_dir+0xc4/0x)
one_wire_status: 2
[<c00ee828>] (sysfs_create_dir+0xc4/0xec) from [<c0194064>] (kobject_add_intern)
[<c0194064>] (kobject_add_internal+0xd0/0x1a4) from [<c01942b0>] (kobject_add+0)
one_wire_status: 3
[<c01942b0>] (kobject_add+0x4c/0x5c) from [<c01d5b98>] (device_add+0xa0/0x500)
[<c01d5b98>] (device_add+0xa0/0x500) from [<c01d6098>] (device_create_vargs+0x8)
[<c01d6098>] (device_create_vargs+0x88/0xbc) from [<c01d60e4>] (device_create+0)
one_wire_status: 4
[<c01d60e4>] (device_create+0x18/0x20) from [<c01d3fe4>] (misc_register+0xb8/0x)
[<c01d3fe4>] (misc_register+0xb8/0x128) from [<bf003040>] (dev_init+0x40/0x60 [)
one_wire_status: 4
[<bf003040>] (dev_init+0x40/0x60 [leds_misc]) from [<c002a40c>] (do_one_initcal)
[<c002a40c>] (do_one_initcall+0xc8/0x19c) from [<c0071624>] (sys_init_module+0x)
[<c0071624>] (sys_init_module+0x12b4/0x1454) from [<c0034de0>] (ret_fast_syscal)
one_wire_status: 4
---[ end trace 9d6931ccd5e8f11c ]---
kobject_add_internal failed for leds with -EEXIST, don't try to register things.
one_wire_status: 4
[<c003a570>] (unwind_backtrace+0x0/0xec) from [<c01940f0>] (kobject_add_interna)
[<c01940f0>] (kobject_add_internal+0x15c/0x1a4) from [<c01942b0>] (kobject_add+)
one_wire_status: 4
[<c01942b0>] (kobject_add+0x4c/0x5c) from [<c01d5b98>] (device_add+0xa0/0x500)
[<c01d5b98>] (device_add+0xa0/0x500) from [<c01d6098>] (device_create_vargs+0x8)
[<c01d6098>] (device_create_vargs+0x88/0xbc) from [<c01d60e4>] (device_create+0)
one_wire_status: 4
[<c01d60e4>] (device_create+0x18/0x20) from [<c01d3fe4>] (misc_register+0xb8/0x)
[<c01d3fe4>] (misc_register+0xb8/0x128) from [<bf003040>] (dev_init+0x40/0x60 [)
one_wire_status: 4
[<bf003040>] (dev_init+0x40/0x60 [leds_misc]) from [<c002a40c>] (do_one_initcal)
[<c002a40c>] (do_one_initcall+0xc8/0x19c) from [<c0071624>] (sys_init_module+0x)
one_wire_status: 4
[<c0071624>] (sys_init_module+0x12b4/0x1454) from [<c0034de0>] (ret_fast_syscal)
leds initialized
insmod: can't insert 'leds_misc.ko': File exists 
