分类: LINUX
2009-08-19 19:43:55
//===============adcDriver.c==================================================
#ifndef __KERNEL__
#define __KERNEL__
#endif
#ifndef MODULE
#define MODULE
#endif
#include
#include
#include/* printk() */
#include/* __init __exit */
#include/* size_t */
#include/* file_operation */
#include/* Error number */
#include/* udelay */
#include/* copy_to_user, copy_from_user */
#include
#include
#define DRIVER_NAME "adc"
#ifdef DEBUG
#define PRINTK(fmt, arg...) printk(KERN_NOTICE fmt, ##arg)
#else
#define PRINTK(fmt, arg...)
#endif
/*
KERN_EMERG 用于紧急事件,一般是系统崩溃前的提示信息
KERN_ALERT 用于需要立即采取动作的场合
KERN_CRIT 临界状态,通常设计验证的硬件或软件操作失败
KERN_ERR 用于报告错误状态.设备驱动程序通常会用它报告来自硬件的问题
KERN_WARNING 就可能出现的问题提出警告.这些问题通常不会对系统造成严重破坏
KERN_NOTICE 有必要提示的正常情况.许多安全相关的情况用这个级别汇报
KERN_INFO 提示性信息.有很多驱动程序在启动时用这个级别打印相关信息
KERN_DEBUG 用于调试的信息
*/
int count=0;
static int adc_Marjor = 0; /* Driver Major Number */
/* Driver Operation Functions */
static int adc_open(struct inode *inode, struct file *filp)
{
MOD_INC_USE_COUNT;
ADCCON |= 0x2;
ADCDLY = 100; //ADC转换延时
printk("adc open called!\n");
return 0;
}
static int adc_release(struct inode *inode, struct file *filp)
{
MOD_DEC_USE_COUNT;
ADCCON &= 0x0;
PRINTK("adcDriver release called!\n");
return 0;
}
static ssize_t adc_read(struct file *filp, char *buf, size_t count, loff_t *f_pos)
{
int i,j;
int val,aa;
val = 0;
aa = ADCDAT0 & 0x03ff; //启动ADC转换,读出的第一个数是无效的
for(i=0;i<16;i++)
{
while(!ADCCON&0x8000); //判断ADC转换是否结束
val += (ADCDAT0 &0x03ff); //取出ADC转换值
for(j=0;j<500;j++);
}
val = val/16;
copy_to_user(buf, &val, sizeof(val));
PRINTK("read:ADCData=0x%x,count=%d\n", val, count);
return sizeof(val);
}
static int adc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
if(arg>0 && arg <7)
{
switch(cmd)
{
case 0:
ADCCON |= (arg << 3);
break;
default:
break;
}
return 0;
}
else
printk("error:adc channel is 0~7\n");
return 0;
}
/* Driver Operation structure */
static struct file_operations adc_fops = {
owner: THIS_MODULE,
read: adc_read,
ioctl: adc_ioctl,
open: adc_open,
release:adc_release,
};
/* Module Init & Exit function */
#ifdef CONFIG_DEVFS_FS
devfs_handle_t devfs_adcDriver_dir;
devfs_handle_t devfs_adcDriver_raw;
#endif
static int __init myModule_init(void)
{
/* Module init code */
PRINTK("myModule_init\n");
/* Driver register */
adc_Marjor = register_chrdev(0, DRIVER_NAME, &adc_fops);
if(adc_Marjor < 0)
{
PRINTK("register char device fail!\n");
return adc_Marjor;
}
PRINTK("register adc OK! Major = %d\n", adc_Marjor);
#ifdef CONFIG_DEVFS_FS
devfs_adcDriver_dir = devfs_mk_dir(NULL, "adc", NULL);
devfs_adcDriver_raw = devfs_register(devfs_adcDriver_dir, "0", DEVFS_FL_DEFAULT, adc_Marjor, 0, S_IFCHR | S_IRUSR | S_IWUSR, &adc_fops, NULL);
PRINTK("add dev file to devfs OK!\n");
#endif
ADCCON = (0 << 0)| // ADC转换设置 未设置
(0 << 1)| // 读AD数据触发AD转换 未使用
(0 << 2)| // StandBy模式选择 为普通操作模式
(0 << 3)| // ADC通道选择
(49 << 6)| // CLKDIV = Fpclk /49+1/5 ,即转换时钟为1MHz Fpclk = 10M ADC转换频率400K
(1 << 14); // 使能软件预设值
return 0;
}
static void __exit myModule_exit(void)
{
/* Module exit code */
PRINTK("myModule_exit\n");
/* Driver unregister */
if(adc_Marjor > 0)
{
#ifdef CONFIG_DEVFS_FS
devfs_unregister(devfs_adcDriver_raw);
devfs_unregister(devfs_adcDriver_dir);
#endif
unregister_chrdev(adc_Marjor, DRIVER_NAME);
}
return;
}
MODULE_AUTHOR("sure");
MODULE_LICENSE("Dual BSD/GPL");
module_init(myModule_init);
module_exit(myModule_exit);
//===========Makefile=========================================================
OUTPUT = adcDriver.o
OUTPUT_DIR = ./
#s3c2410
KERNEL = /home/sure/kernel_2.4.18
CROSSPREFIX = /usr/local/arm/2.95.3/bin/arm-linux-
#pc 2.4
#KERNEL = /usr/src/linux-2.4
#CROSSPREFIX =
CFLAGS = -Wall -I$(KERNEL)/include -c -DDEBUG
#CFLAGS += -DEXPORT_SYMTAB -DMODVERSIONS -include $(KERNEL)/include/linux/modversions.h
DEST = $(foreach fn, $(OUTPUT), $(OUTPUT_DIR)/$(fn))
all: $(OUTPUT_DIR)/install.sh
$(OUTPUT_DIR)/install.sh: $(OUTPUT_DIR) $(DEST)
@rm $@ -f
@echo -e " $(foreach fn, $(OUTPUT), "insmod $(fn)\\n")" >> $@
@echo "Finished!"
$(OUTPUT_DIR):
@mkdir $@
@chmod 777 -R $@
$(OUTPUT_DIR)/%.o: %.c
@echo -n "Compling $^..."
@$(CROSSPREFIX)gcc $(CFLAGS) $^ -o $@
@echo "OK"
clean:
@find . \( -name '*.[oas]' -o -name install.sh \) -type f -print | xargs rm -f
@echo "Cleaned!"
//======================test.c============================================
#include
#include
#include
#include
#include
#define ADC_SET_CHANNEL 0
main()
{
int fd;
int ret;
int data;
fd = open("/dev/adc/0",O_RDWR);
if(fd<0)
printf("open /dev/adc/0 error");
ret = ioctl(fd,ADC_SET_CHANNEL,1);
while(1)
{
ret = read(fd,&data,4);
printf("adc is %d\n",data);
sleep(1);
}
}