分类： 嵌入式
2011-09-28 21:52:41
/************************************************
ADC的驱动，在TX2440A开发板上做测试
维护记录： 2009-10-20 V1.0
linux内核：2.6.31
硬件接法：
RP1 --> ADC CH0
RP2 --> ADC CH1
驱动用法：
设备名称：TX2440-adc
*************************************************/
#include
#include
#include
#include
#include
#include
#include
#include
//#include
#include
#include
//#include
#include
#include
#define DEVICE_NAME "TX2440-adc" /* 设备名称 */
static int ADC_Major = 0; /* 主设备号 */
static void __iomem *base_addr;
static int adc_ch;
#define ADCCON (*(volatile unsigned long *)(base_addr + S3C2410_ADCCON)) //ADC control
#define ADCTSC (*(volatile unsigned long *)(base_addr + S3C2410_ADCTSC)) //ADC touch screen control
#define ADCDLY (*(volatile unsigned long *)(base_addr + S3C2410_ADCDLY)) //ADC start or Interval Delay
#define ADCDAT0 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT0)) //ADC conversion data 0
#define ADCDAT1 (*(volatile unsigned long *)(base_addr + S3C2410_ADCDAT1)) //ADC conversion data 1
void ADC_Init(void)
{
ADCDLY = 100; //ADC转换延时
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
// (ch << 3) | // ADC通道选择 ch
(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
}
int AD_READ(void)
{
int val;
val = 0;
ADCCON |= 0x1; //ADC转换通过读操作来启动
while(ADCCON&0x1); //判断ADC转换是否结束
while(!ADCCON&0x8000); //判断ADC转换是否结束
val = (ADCDAT0 &0x03ff); //取出ADC转换值
mdelay(100);
return val;
}
static int TX2440_adc_open(struct inode *inode, struct file *file)
{
printk("TX2440-ADC Driver Open Called!\n");
return 0;
}
static int TX2440_adc_release(struct inode *inode, struct file *file)
{
printk("TX2440-ADC Driver Release Called!\n");
return 0;
}
static int TX2440_adc_read(struct file *filp, char *buf, size_t count, loff_t *f_pos)
{
int adc_val = AD_READ();
copy_to_user(buf, &adc_val, sizeof(adc_val));
return sizeof(adc_val);
}
static int TX2440_adc_ioctl( struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
adc_ch = cmd;
ADCCON &= 0xFFC7;
ADCCON |= (adc_ch << 3);
return 0;
}
static struct file_operations TX2440_adc_fops =
{
.owner = THIS_MODULE,
.open = TX2440_adc_open,
.release = TX2440_adc_release,
.ioctl = TX2440_adc_ioctl,
.read = TX2440_adc_read,
};
static struct class *adc_class;
static int __init TX2440_adc_init(void)
{
printk("TX2440 ADC DRIVER MODULE INIT\n");
base_addr=ioremap(S3C2410_PA_ADC,0x20);
if (base_addr == NULL) {
printk(KERN_ERR "Failed to remap register block\n");
return -ENOMEM;
}
ADC_Init(); //ADC初始化
ADC_Major = register_chrdev(0, DEVICE_NAME, &TX2440_adc_fops);
if (ADC_Major < 0)
{
printk(DEVICE_NAME " can't register major number\n");
return ADC_Major;
}
printk("register TX2440-ADC Driver OK! Major = %d\n", ADC_Major);
adc_class = class_create(THIS_MODULE, DEVICE_NAME);
if(IS_ERR(adc_class))
{
printk("Err: failed in TX2440-ADC class. \n");
return -1;
}
device_create(adc_class, NULL, MKDEV(ADC_Major, 0), NULL, DEVICE_NAME);
printk(DEVICE_NAME " initialized\n");
return 0;
}
static void __exit TX2440_adc_exit(void)
{
printk("TX2440 ADC DRIVER MODULE EXIT\n");
unregister_chrdev(ADC_Major, DEVICE_NAME);
device_destroy(adc_class, MKDEV(ADC_Major, 0));
class_destroy(adc_class);
}
module_init(TX2440_adc_init);
module_exit(TX2440_adc_exit);
MODULE_AUTHOR("www.txmcu.com");
MODULE_DESCRIPTION("TX2440 ADC Driver");
MODULE_LICENSE("GPL");
源代码：
TX2440_adc.rar
测试程序： adc.rar
