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小弟愚昧,写了一个在linux操作系统,凭借ARM平台来驱动ADC芯片MAX188有很大的问题,如果哪位朋友有时间,帮忙看一下吧,不胜感激!敬请指教啊!
程序如下:
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <mach/regs-clock.h>
#include <plat/regs-timer.h>
#include <plat/regs-adc.h>
#include <mach/regs-gpio.h>
#include <linux/cdev.h>
#include <linux/miscdevice.h>
#define HIGH 1
#define LOW 0
spinlock_t mylock=SPIN_LOCK_UNLOCKED;
#define DEVICE_NAME "adc_MAX188"
//定义使用的管脚
#define MAX188_PIN_CS S3C2410_GPB5
#define MAX188_PIN_SCLK S3C2410_GPB6
#define MAX188_PIN_DIN S3C2410_GPB7
#define MAX188_PIN_DOUT S3C2410_GPB8
#define MAX188_PIN_SSTRB S3C2410_GPG13
//定义管脚所要实现的管脚
#define MAX188_PIN_CS_set S3C2410_GPB5_OUTP
#define MAX188_PIN_SCLK_set S3C2410_GPB6_OUTP
#define MAX188_PIN_DIN_set S3C2410_GPB7_OUTP
#define MAX188_PIN_DOUT_set S3C2410_GPB8_INP
#define MAX188_PIN_SSTRB_set S3C2410_GPG13_OUTP
static unsigned int ad_data;//ADC转换后的数据,
static unsigned int wData;
static unsigned char ctr_word=0x87; //定义max188的控制字
static unsigned char SelTab[]={0,4,1,5,2,6,3,7};
static unsigned long gpio_table [] =
{
MAX188_PIN_CS,
MAX188_PIN_SCLK,
MAX188_PIN_DIN,
MAX188_PIN_DOUT,
MAX188_PIN_SSTRB,
};
static unsigned int gpio_cfg_table [] =
{
MAX188_PIN_CS_set,
MAX188_PIN_SCLK_set,
MAX188_PIN_DIN_set,
MAX188_PIN_DOUT_set,
MAX188_PIN_SSTRB_set,
};
unsigned int readmax188(void)
{
unsigned int i,value=0
value=ctr_word|(SelTab[value]<<4);
s3c2410_gpio_setpin(MAX188_PIN_CS, LOW);
udelay(100);
s3c2410_gpio_setpin(MAX188_PIN_DOUT, HIGH);
udelay(1);
for(i=0;i<8;i++)
{
s3c2410_gpio_setpin(MAX188_PIN_SCLK, LOW);
udelay(1);
if(value&0x80)
{
s3c2410_gpio_setpin(MAX188_PIN_DIN, HIGH);
udelay(1);
}
else
{
s3c2410_gpio_setpin(MAX188_PIN_DIN, LOW);
udelay(1);
}
value=(value<<1);
printk("11value is : %d\n",value);
udelay(6);
s3c2410_gpio_setpin(MAX188_PIN_SCLK, HIGH);
udelay(1);
}
while(s3c2410_gpio_getpin(MAX188_PIN_SSTRB)==1)
{
udelay(6);
}
s3c2410_gpio_setpin(MAX188_PIN_SCLK, LOW);
udelay(10);
for(i=0;i<16;i++)
{
s3c2410_gpio_setpin(MAX188_PIN_SCLK, HIGH);
udelay(1);
if(s3c2410_gpio_getpin(MAX188_PIN_DOUT))
{
wData+=1;
}
wData<<=1;
udelay(6);
s3c2410_gpio_setpin(MAX188_PIN_SCLK, LOW);
udelay(1);
}
printk("wdata value is: %d\n",wData);
s3c2410_gpio_setpin(MAX188_PIN_CS, HIGH);
udelay(5);
return(wData>>4);
}
static void adMAX188_PIN_int(void)
{
int i;
for (i = 0; i < 5; i++)
{
s3c2410_gpio_cfgpin(gpio_table, gpio_cfg_table);
}
}
static int MAX188_open(struct inode *inode, struct file *filp)
{
adMAX188_PIN_int();
printk( DEVICE_NAME"ADC opened\n");
return 0;
}
static int MAX188_read(struct file *filp, char *buffer, size_t count, loff_t *ppos)
{
unsigned int DD;
spin_lock(&mylock);
ad_data=readmax188();
DD=readw(S3C2410_GPBCON);
printk("DD=%d\n",DD);
copy_to_user(buffer, (char *)&ad_data, sizeof(ad_data));
printk("ad_data=%d\n",ad_data);
spin_unlock(&mylock);
return 0;
}
static int MAX188_release(struct inode *inode, struct file *filp)
{
printk( DEVICE_NAME"ADC closed\n");
return 0;
}
static struct file_operations MAX188_fops = {
.owner = THIS_MODULE,
.open = MAX188_open,
.read = MAX188_read,
.release =MAX188_release,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &MAX188_fops,
};
static int __init s3c2440_adMAX188_int(void)
{
int ret;
//adMAX188_PIN_int();.//在此处初始化管脚功能,不知怎的出问题:
ret = misc_register(&misc);
printk (DEVICE_NAME "initialized\n");
return ret;
}
static void __exit s3c2440_adMAX188_exit(void)
{
misc_deregister(&misc);
}
module_init(s3c2440_adMAX188_int);
module_exit(s3c2440_adMAX188_exit);
MODULE_LICENSE("GPL");
执行后的结果
执行后在串口终端显示的情况 (原文件名:5.jpg)
ad_data是ADC转换后的结果,但是在重复执行应用程序的时候,该数值不变化!
DD是读取的GPB数据寄存器的结果
11value打印的是写控制字时的value值
value=(value<<1);
printk("11value is : %d\n",value);
wData是数据读取后的返回值
return(wData>>4);
敬请帮忙看看啊。
给我的外扩ADC的驱动给个建议吧
谢谢啊 |
阿莫论坛20周年了!感谢大家的支持与爱护!!
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