mini2440 LED驱动程序开发

一、源代码：
 
/***********************mini2440_leds.c***********************
 
*
 
*
 
*******************************************************************/
 
#include <linux/miscdevice.h>
 #include
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 #include   //2.6.32.2内核版本要求
 
#define DEVICE_NAME 'leds'
 //定义GPIO管脚
 static unsigned long led_table [] = {
  S3C2410_GPB(5),  //不能是S3C2410_GPB5;  因为没有这样定义，可以通过#define S3C2410_GPB5 S3C2410_GPB(5)
  S3C2410_GPB(6),
  S3C2410_GPB(7),
  S3C2410_GPB(8),
 };
 //设置管脚模式
 static unsigned int led_cfg_table [] = {
  S3C2410_GPIO_OUTPUT, //随内核版本中定义类型的变化，
  S3C2410_GPIO_OUTPUT,
  S3C2410_GPIO_OUTPUT,
  S3C2410_GPIO_OUTPUT,
 };
 //ioctl函数实现
 static int sbc2440_leds_ioctl(
  struct inode *inode,
 struct file *file,
 unsigned int cmd,
 unsigned long arg)
 {
  switch(cmd) {
  case 0:
  case 1:
  if (arg > 4) {
    return -EINVAL;
  }
  s3c2410_gpio_setpin(led_table[arg], !cmd);
  return 0;
  default:
  return -EINVAL;
  }
 }
 //dev_fops操作指令集
 static struct file_operations dev_fops = {
  .owner =THIS_MODULE,
  .ioctl =sbc2440_leds_ioctl,
 };
 //第三步：混杂设备定义
 static struct miscdevice misc = {
  .minor = MISC_DYNAMIC_MINOR,
  .name = DEVICE_NAME,
  .fops = &dev_fops,
 };
 //第二步：gpio模式选择，设定管脚
 //  注册混杂设备
 static int __init dev_init(void)
 {
  int ret;
 
 int i;
 
  for (i = 0; i < 4; i++) {
  s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);
  s3c2410_gpio_setpin(led_table[i], 0);
  }
 
 ret = misc_register(&misc);
 
 printk (DEVICE_NAME'tinitializedn');
 
 return ret;
 }
 
static void __exit dev_exit(void)
 {
  misc_deregister(&misc);
 }
 //第一步：module_init(dev_init);
 //    module_exit(dev_exit);
 module_init(dev_init);
 module_exit(dev_exit);
 MODULE_LICENSE('GPL');
 MODULE_AUTHOR('FriendlyARM Inc.');
 
/**************************Makefile文件************************
 
*
 
*
 
*****************************************************************/
 
ifneq ($(KERNELRELEASE),)
 
obj-m := mini2440_leds.o
 
else
  KDIR:=/home/kernel/linux-2.6.32.2
 all:
  make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-
 clean:
  rm -f *.ko *.o *.mod.o *.mod.c *.symvers  modul*
 

endif

二、测试LED驱动的APP程序
 /*******************************app_leds.c***************************************
 
*
 
*
 
**********************************************************************************/
 
ifneq ($(KERNELRELEASE),)
 
obj-m := mini2440_leds.o
 
else
  KDIR:=/home/kernel/linux-2.6.32.2
 all:
  make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-
 clean:
  rm -f *.ko *.o *.mod.o *.mod.c *.symvers  modul*
 
endif
 
三、遇到的问题
 1、
 [root@localhost LED]# make
make -C /home/kernel/linux-2.6.32.2 M=/home/nfsshare/root_qtopia/Drive/LED modules ARCH=arm CROSS_COMPILE=arm-linux-
 make[1]: Entering directory `/home/kernel/linux-2.6.32.2'
  CC [M]  /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.o
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:29: error: 'S3C2410_GPB5' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:30: error: 'S3C2410_GPB6' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:31: error: 'S3C2410_GPB7' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:32: error: 'S3C2410_GPB8' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:36: error: 'S3C2410_GPB5_OUTP' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:36: error: initializer element is not constant
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:36: error: (near initialization for 'led_cfg_table[0]')
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:37: error: 'S3C2410_GPB6_OUTP' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:37: error: initializer element is not constant
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:37: error: (near initialization for 'led_cfg_table[1]')
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:38: error: 'S3C2410_GPB7_OUTP' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:38: error: initializer element is not constant
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:38: error: (near initialization for 'led_cfg_table[2]')
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:39: error: 'S3C2410_GPB8_OUTP' undeclared here (not in a function)
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:39: error: initializer element is not constant
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:39: error: (near initialization for 'led_cfg_table[3]')
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c: In function 'sbc2440_leds_ioctl':
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:54: error: implicit declaration of function 's3c2410_gpio_setpin'
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c: In function 'dev_init':
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:80: error: implicit declaration of function 's3c2410_gpio_cfgpin'
 make[2]: *** [/home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.o] 错误 1
 make[1]: *** [_module_/home/nfsshare/root_qtopia/Drive/LED] 错误 2
 make[1]: Leaving directory `/home/kernel/linux-2.6.32.2'
 make: *** [all] 错误 2
 错误原因：内核版本不对，没有S3C2410_GPB5的类型定义 需要修改为S3C2410_GPB(5)
 
内核版本定义如下：
 
/* arch/arm/mach-s3c2410/include/mach/gpio-nrs.h
  *
  * Copyright (c) 2008 Simtec Electronics
  * http://armlinux.simtec.co.uk/
  * Ben Dooks <ben@simtec.co.uk>
  *
  * S3C2410 - GPIO bank numbering
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
 */
 
#ifndef __MACH_GPIONRS_H
 #define __MACH_GPIONRS_H
 
#define S3C2410_GPIONO(bank,offset) ((bank) + (offset))
 
#define S3C2410_GPIO_BANKA  (32*0)
 #define S3C2410_GPIO_BANKB  (32*1)
 #define S3C2410_GPIO_BANKC  (32*2)
 #define S3C2410_GPIO_BANKD  (32*3)
 #define S3C2410_GPIO_BANKE  (32*4)
 #define S3C2410_GPIO_BANKF  (32*5)
 #define S3C2410_GPIO_BANKG  (32*6)
 #define S3C2410_GPIO_BANKH  (32*7)
 
/* GPIO bank sizes */A
 #define S3C2410_GPIO_A_NR (32)
 #define S3C2410_GPIO_B_NR (32)
 #define S3C2410_GPIO_C_NR (32)
 #define S3C2410_GPIO_D_NR (32)
 #define S3C2410_GPIO_E_NR (32)
 #define S3C2410_GPIO_F_NR (32)
 #define S3C2410_GPIO_G_NR (32)
 #define S3C2410_GPIO_H_NR (32)
 
#if CONFIG_S3C_GPIO_SPACE != 0
 #error CONFIG_S3C_GPIO_SPACE cannot be zero at the moment
 #endif
 
#define S3C2410_GPIO_NEXT(__gpio)
  ((__gpio##_START) + (__gpio##_NR) + CONFIG_S3C_GPIO_SPACE + 0)
 
#ifndef __ASSEMBLY__
 
enum s3c_gpio_number {
  S3C2410_GPIO_A_START = 0,
  S3C2410_GPIO_B_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_A),
  S3C2410_GPIO_C_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_B),
  S3C2410_GPIO_D_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_C),
  S3C2410_GPIO_E_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_D),
  S3C2410_GPIO_F_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_E),
  S3C2410_GPIO_G_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_F),
  S3C2410_GPIO_H_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_G),
 };
 
#endif /* __ASSEMBLY__ */
 
/* S3C2410 GPIO number definitions. */
 
#define S3C2410_GPA(_nr) (S3C2410_GPIO_A_START + (_nr))
 #define S3C2410_GPB(_nr) (S3C2410_GPIO_B_START + (_nr))
 #define S3C2410_GPC(_nr) (S3C2410_GPIO_C_START + (_nr))
 #define S3C2410_GPD(_nr) (S3C2410_GPIO_D_START + (_nr))
 #define S3C2410_GPE(_nr) (S3C2410_GPIO_E_START + (_nr))
 #define S3C2410_GPF(_nr) (S3C2410_GPIO_F_START + (_nr))
 #define S3C2410_GPG(_nr) (S3C2410_GPIO_G_START + (_nr))
 #define S3C2410_GPH(_nr) (S3C2410_GPIO_H_START + (_nr))
 
/* compatibility until drivers can be modified */
 
//宏定义了GPA和GPE
 
#define S3C2410_GPA0 S3C2410_GPA(0)
 #define S3C2410_GPA1 S3C2410_GPA(1)
 #define S3C2410_GPA3 S3C2410_GPA(3)
 #define S3C2410_GPA7 S3C2410_GPA(7)
 
#define S3C2410_GPE0 S3C2410_GPE(0)
 #define S3C2410_GPE1 S3C2410_GPE(1)
 #define S3C2410_GPE2 S3C2410_GPE(2)
 #define S3C2410_GPE3 S3C2410_GPE(3)
 #define S3C2410_GPE4 S3C2410_GPE(4)
 #define S3C2410_GPE5 S3C2410_GPE(5)
 #define S3C2410_GPE6 S3C2410_GPE(6)
 #define S3C2410_GPE7 S3C2410_GPE(7)
 #define S3C2410_GPE8 S3C2410_GPE(8)
 #define S3C2410_GPE9 S3C2410_GPE(9)
 #define S3C2410_GPE10 S3C2410_GPE(10)
 
#define S3C2410_GPH10 S3C2410_GPH(10)
 
#endif /* __MACH_GPIONRS_H */
 
2、问题二
 
[root@localhost LED]# make
 make -C /home/kernel/linux-2.6.32.2 M=/home/nfsshare/root_qtopia/Drive/LED modules ARCH=arm CROSS_COMPILE=arm-linux-
 make[1]: Entering directory `/home/kernel/linux-2.6.32.2'
  CC [M]  /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.o
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c: In function 'sbc2440_leds_ioctl':
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:54: error: implicit declaration of function 's3c2410_gpio_setpin'
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c: In function 'dev_init':
 /home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.c:80: error: implicit declaration of function 's3c2410_gpio_cfgpin'
 make[2]: *** [/home/nfsshare/root_qtopia/Drive/LED/mini2440_leds.o] 错误 1
 make[1]: *** [_module_/home/nfsshare/root_qtopia/Drive/LED] 错误 2
 make[1]: Leaving directory `/home/kernel/linux-2.6.32.2'
 
原因：没有声明s3c2410_gpio_setpin和s3c2410_gpio_cfpin
 
j解决方法：调价头文件#include
 
3、问题三
 
在securecat中加载mini2440.ko文件，出现File existed
 
原因：使用的内核已经编译了led驱动模块，因此报错
 
解决：重新编译内核模块，在make menuconfig中不选择led选项