dsp.c

基于linux嵌入式系统,芯片为AC48x的DSP驱动源码以及测试程序

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/modversions.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/param.h>
#include <linux/fs.h>
#include <linux/config.h>
#include <asm/delay.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <linux/malloc.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <linux/init.h>

#define DEVICE_NAME  "/dev/dsp"

#define P_U32 unsigned long *

#define HPIC 0xD0000000
#define HPIDI 0xD0000004
#define HPIA  0xD0000008
#define HPID  0xD000000C

#define DEVICE_RESET 100
   /*Control Register*/
#define HPIC1stWr 0          /*Write first byte */
#define HPIC2ndWr 1          /*Write second byte*/
#define HPIC1stRd 2          /*Read first byte*/
#define HPIC2ndRd 3          /*Read second byte*/
/*Data transfer with Post increment after read and preincrement before write.*/
#define HPI1stWr 4           /*Write first byte */
#define HPI2ndWr 5           /*Write second byte*/
#define HPI1stRd 6           /*Read first byte*/
#define HPI2ndRd 7           /*Read second byte*/
        /*Address Register*/
#define HPIA1stWr 8          /*Write first byte */
#define HPIA2ndWr 9          /*Write second byte*/
#define HPIA1stRd 10          /*Read first byte*/
#define HPIA2ndRd 11          /*Read second byte*/
        /*Data Latches*/
#define HPIDL1stWr 12         /*Write first byte */
#define HPIDL2ndWr 13          /*Write second byte*/
#define HPIDL1stRd 14         /*Read first byte*/
#define HPIDL2ndRd 15         /*Read second byte*/

static short Major;

static ssize_t aaa_read(struct file *file, char *buf,size_t len, loff_t *off)
{
  int err;
  char *kbuf;
  int i;

  kbuf=kmalloc(len,GFP_KERNEL);
  if(kbuf==NULL)return -1;

  for(i=0;i<len/2;i++){
    kbuf[2*i]=*(unsigned char *)(0xD0000000+HPI1stRd);           
    kbuf[2*i+1]=*(unsigned char *)(0xD0000000+HPI2ndRd);
  } 

  err=copy_to_user(&buf[0],kbuf,len);
  kfree(kbuf);  
  if(err) return -1;
  else return len;
}

static ssize_t aaa_write(struct file *file, const char *buf,size_t len, loff_t *off)
{
  int err;
  char *kbuf;
  int i;

  kbuf=kmalloc(len,GFP_KERNEL);
  if(kbuf==NULL)return -1;

  err=copy_from_user(kbuf,&buf[0],len);
  if(err){
    kfree(kbuf);
    return -1;
  }

  for(i=0;i<len/2;i++){
    *(unsigned char *)(0xD0000000+HPI1stWr)=kbuf[i*2];           
    *(unsigned char *)(0xD0000000+HPI2ndWr)=kbuf[i*2+1]; 
  }

  kfree(kbuf);
  return len;
}

static int aaa_ioctl(struct inode *inodp,struct file *filp,unsigned int command,unsigned long arg)
{
  int err; 
  unsigned long para;

  err=copy_from_user((void *)&para,(void*)(arg),sizeof(para));
  if(err){
    printk("wrong\n");
    return err;
  }	

 
  if(command==DEVICE_RESET){

	
    *(volatile P_U32)(0xf021c308) |=0x30000000;  //set bits in OCR2_D
  
    *(volatile P_U32)(0xf021c31c) &=0xBFFFFFFF;  //write to bit of DR_D
    *(volatile P_U32)(0xf021c300) |=0x40000000;  //Set bit in DDIRD

    udelay(70);

    *(volatile P_U32)(0xf021c31c) |=0x40000000;  //write to bit of DR_D
    *(volatile P_U32)(0xf021c300) |=0x40000000;  //Set bit in DDIRD

    return 0;
  }

    if(command>=0 && command<16){
      switch(command % 4){
      case 0:
      case 1:
	*(unsigned char *)(0xD0000000+command)=para;
	break;
      case 2:
      case 3:
	para=*(unsigned char *)(0xD0000000+command);
	break;
      }
    }
    else return -1;

  err=copy_to_user((void*)(arg),(void *)&para,sizeof(para));
  if(err){
    printk("error\n");
    return err;
  }
  return 0;	
}

static int aaa_open(struct inode * inodp,struct file* fp)
{  
  return 0;
}

static int aaa_release(struct inode * inodp,struct file *filp)
{
  return 0;
}



/**************************KERNEL RELATIVE************************/
static struct file_operations aaa_fops ={
  NULL,
  NULL,//llseek
  aaa_read,
  aaa_write,
  NULL,//readdir
  NULL,//poll
  aaa_ioctl,
  NULL,//mmap,
  aaa_open,
  NULL,//flush,
  aaa_release,
  NULL,// fsync
  NULL,//fasync
  NULL,//lock
  NULL,//readv
  NULL,//writev
  NULL,//sendpage
  NULL//get_unmapped_area
};

int init_module(void)
{
  Major=register_chrdev(0,DEVICE_NAME,&aaa_fops);
  if(Major<0)
    {
      printk("<1>sorry,cannot open device %s,your device number is %d\n",DEVICE_NAME,Major);
      return Major;
    }
  printk("<1>succed in allocating a device number,which is %d\n",Major);
  
  return 0;
}

void cleanup_module(void)
{
  int ret;
  ret=unregister_chrdev(Major,DEVICE_NAME);
  ret<0 ? printk("Error in unregistering %s\n",DEVICE_NAME):printk("Success in unregistering %s\n",DEVICE_NAME);
}