addrv.c

at91rm9200 AD/DA转换驱动 很好的驱动开发范例

/* AD convert driver for H9200M and H9200T board 
   Author: Wei An
   E-Mail: [e-mail]/[e-mail]
   Date:   2005/6/1
*/
#ifdef MODULE
#include <linux/module.h>
#include <linux/version.h>
#else
#endif

#define __KERNEL__
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/fcntl.h>
#include <asm/arch/AT91RM9200_SYS.h>



#define AD_PHYSICAL_REG_SIZE ((unsigned int)    0x00000004)
#define AD_PHYSICAL_CH_ADDR ((unsigned int)     0x80000010)
#define AD_PHYSICAL_CH_SIZE ((unsigned int)     0x00000002)

#define AT91C_ADC_NCS7      ((unsigned int) 	0x80000020)
#define AT91C_ADC_RD        ((unsigned int) 	0x80000030)

#define AT91C_SEL_CH0         ((unsigned char )0x80000010)
#define AT91C_SEL_CH1         ((unsigned char )0x80000012)
#define AT91C_SEL_CH2         ((unsigned char )0x80000014)
#define AT91C_SEL_CH3         ((unsigned char )0x80000016)
#define AT91C_SEL_CH4         ((unsigned char )0x80000018)
#define AT91C_SEL_CH5         ((unsigned char )0x8000001a)
#define AT91C_SEL_CH6         ((unsigned char )0x8000001c)
#define AT91C_SEL_CH7         ((unsigned char )0x8000001e)

//global variables def
volatile unsigned int * ADC_NCS7;
volatile unsigned int * ADC_RD;

volatile unsigned char * SEL_CH0;
volatile unsigned char * SEL_CH1;
volatile unsigned char * SEL_CH2;
volatile unsigned char * SEL_CH3;
volatile unsigned char * SEL_CH4;
volatile unsigned char * SEL_CH5;
volatile unsigned char * SEL_CH6;
volatile unsigned char * SEL_CH7;

//local variables def
static int AD_read(struct file *, char *,int,loff_t *);
static int AD_write(struct file *,const char *,int,loff_t *);

static struct file_operations ad_fops=
{
      write     :(void(*))AD_write,
      read      :(void(*))AD_read,
};
char ad_name[]="addrv";
static unsigned int major =0;

static void Delay (int);
/* Configure pio */
void AT91_CfgPIO_AD(void)
{
     AT91PS_SYS sys = (AT91PS_SYS) AT91C_VA_BASE_SYS;
     // Enable PIOC
     sys->PIOC_PDR=(unsigned int)(1<<13);
     // Select Peripheral A         
     sys->PIOC_ASR=(unsigned int)(1<<13);
}
/* AD convert */
short  Convert()
{     
      unsigned short t;
      int temp;       
      writel(0x0,ADC_NCS7); 
      Delay(400);
      writel(0x0,ADC_NCS7); 
      t=readl(ADC_RD)&0x0fff0000>>16;
      return t;
     
      
}
/* Read convert result and transfer it to user space */
static int AD_read(struct file *AD_file, char *buf,int len,loff_t *loff)
{
       short iopdata=0;
       iopdata=Convert();
       if(copy_to_user(buf,(char*)&iopdata,len))
          return -EFAULT;
       return len;
}
/* Select channel for anolog voltage input */
static int AD_write(struct file *AD_file, const char *buf,int len,loff_t *loff)
{
       int retv;
       unsigned char iopdata;
       /* obtain channel selection data from user space */
       if(copy_from_user((char*)&iopdata,buf,len))
         return -EFAULT;
       switch(iopdata)
       {
        
        case '0':
        
             writeb(0x0,SEL_CH0);     
             break;
        case '1':
             
             writeb(0x0,SEL_CH1);        
             break;  
        case '2':
        
             writeb(0x0,SEL_CH2);      
             
             break;
        case '3':
        
             writeb(0x0,SEL_CH3); 
             
             break;  
        case '4':
        
             writeb(0x0,SEL_CH4); 
             
             break;  
        case '5':
        
             writeb(0x0,SEL_CH5); 
             
             break;
        case '6':
        
             writeb(0x0,SEL_CH6); 
             
             break;
        case '7':
        
             writeb(0x0,SEL_CH7); 
             
             break; 
        default:
             break;    
      }
        Delay(4000);
return len;     
}
/*
 * Main initialization routine
 */

static int __init AD_at91_init(void)
{
       int retv;
       AT91PS_SYS sys = (AT91PS_SYS) AT91C_VA_BASE_SYS;
       
       sys->EBI_SMC2_CSR[7] =(AT91C_SMC2_NWS & 0xff) | AT91C_SMC2_WSEN \
       | (AT91C_SMC2_TDF & 0x300) | AT91C_SMC2_BAT | AT91C_SMC2_DBW_16;

       AT91_CfgPIO_AD();
       /* map hardware I/O address to virtual memory address */
       ADC_NCS7=(unsigned int*)ioremap(AT91C_ADC_NCS7,AD_PHYSICAL_REG_SIZE);
       ADC_RD=(unsigned int*)ioremap(AT91C_ADC_RD,AD_PHYSICAL_REG_SIZE);
       SEL_CH0=(unsigned char*)ioremap(AT91C_SEL_CH0,AD_PHYSICAL_CH_SIZE);
       SEL_CH1=(unsigned char*)ioremap(AT91C_SEL_CH1,AD_PHYSICAL_CH_SIZE);
       SEL_CH2=(unsigned char*)ioremap(AT91C_SEL_CH2,AD_PHYSICAL_CH_SIZE);
       SEL_CH3=(unsigned char*)ioremap(AT91C_SEL_CH3,AD_PHYSICAL_CH_SIZE);
       SEL_CH4=(unsigned char*)ioremap(AT91C_SEL_CH4,AD_PHYSICAL_CH_SIZE);
       SEL_CH5=(unsigned char*)ioremap(AT91C_SEL_CH5,AD_PHYSICAL_CH_SIZE);
       SEL_CH6=(unsigned char*)ioremap(AT91C_SEL_CH6,AD_PHYSICAL_CH_SIZE);
       SEL_CH7=(unsigned char*)ioremap(AT91C_SEL_CH7,AD_PHYSICAL_CH_SIZE);
       /* register module */
       retv=register_chrdev(major,ad_name,&ad_fops);
       if(retv<0)
       {
         printk("<1>Register Fail!\n");
         return retv;
       }
      if(major==0)
        major=retv;
      return 0;
}
/* unregister module */
static void __exit AD_at91_cleanup(void)
{     int retv;
      retv=unregister_chrdev(major,ad_name);
      if(retv<0)
      {
        printk("<1>UnRegister Fail!\n");
        return;
      }
      printk("<1>ADDRV:GOOD-bye!\n");
       
}

void Delay(int i)
{	int j,k;
	for(j=0;j<i;j++)
	{
	k=0;
	}    
}

module_init(AD_at91_init);
module_exit(AD_at91_cleanup);