arm_can_a.c

CAN在S3C2440下的驱动代码

//中断设备程序的编写
//1.编译开关：
//gcc -O2 -D__KERNEL__ -DMODULE -I/usr/src/linux/include -c example.c -o example.o
//2.加载模快：
// insmod  example.o
//3.卸载模快：
//  rmmod 
/*************************  cana中断处理程序  *************************/
//设备名：cana，地址：D0000-D01FF

//#define _debug  //编译调试代码开关
#include <asm/io.h>
#define cana_ADDR        0xfa000000
#define cana_MEM_LEN     0X200  
#define INTERRUPT        0     //使用5号中断
#define MODULE_VERSION   "1.0"
#define MODULE_NAME      "can_a_for_arm"

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/string.h>
#include <asm/io.h> 

static void Sx(int a)
{
  unsigned long volatile *pp = (unsigned long volatile *)0xfe000064;
  
  if(a)*pp|=1;
  else *pp&=0xfffffffe;
  
}
//#define	EnCanW	Sx(0)
//#define 	DisCanW	Sx(1)
#define	EnCanW
#define 	DisCanW

/***************************  can控制器   ***************************/
//1.错误代码定义
#define    EVerify          12     // 写入回读不同
#define    RESET_CAN_OK     13     // 复位成功
#define    RESET_CAN_ERROR  14     // 复位错误
#define    CAN_RESET        15     //
#define    CAN_DEBUG        16     //0XFF
#define    CAN_DEBUG_ERROR  17
#define    CAN_OK           11
#define    CAN_READ_NO_DATA  9     //无数据
#define    CAN_WRITE_BUSY   10     //写数据忙
      
//2.控制寄存器
#define    FlagRR          0x01   // 复位请求
// 命令寄存器
#define    FlagCOS         0x08   // 清除超载
#define    FlagRRB         (0x04)   // 清除接收缓冲,允许接收
#define    FlagAT          0x02   // 中止发送
#define    FlagTR          0x01   // 发送请求
//3.状态寄存器
#define    FlagBS          0x80   // 总线脱离
#define    FlagES          0x40   // 错误
#define    FlagTS          0x20   // 正在发送
#define    FlagRS          0x10   // 正在接收
#define    FlagTCS         0x08   // 发送完成
#define    FlagTBS         0x04   // 发送缓冲可用
#define    FlagDO          0x02   // 数据超载
#define    FlagRBS         0x01   // 接收缓冲有效
//4.中断寄存器
#define    FlagWUI         0x10   // 唤醒中断
#define    FlagOI          0x08   // 超载中断
#define    FlagEI          0x04   // 错误中断
#define    FlagTI          0x02   // 发送中断
#define    FlagRI          0x01   // 接收中断
//5.速度
#define    BTR0_125K       0x03   // 波特率=125Kbps(16MHZ),(3+1)*2=8
#define    BTR1_125K       0x1C   // TSEG1=0x0C=>13,TSEG2=0x01=>2,1+13+2=16
#define    BTR0_500K       0x01   // 波特率=500Kbps(16MHZ),(1+1)*2=4
#define    BTR1_500K       0x14   // TSEG1=0x04=>5,TSEG2=0x01=>2,1+5+2=8
#define    BTR0_1M         0x00   // 波特率=1Mbps(16MHZ),(1)*2=2
#define    BTR1_1M         0x14   // TSEG1=0x04=>5,TSEG2=0x01=>2,1+5+2=8
#define    BTR0_Data       BTR0_500K
#define    BTR1_Data       BTR1_500K
//6.其他
#define    DLCMask         0x0F   // DLC屏蔽
#define    IDLMask         0xE0   // D低字节高3位屏蔽
#define    IDLShift        5      // ID低字节高3位右对齐移位计数
#define    TimeReset       100    // 复位时间,毫秒
char volatile *OUTP;
#define outb(X,Y)   OUTP=(char *)(0xfb000000+Y); *OUTP=X;


struct CanControl 
{
   unsigned char CR; //控制寄存器
   unsigned char CMR;//命令寄存器
   unsigned char SR; //状态寄存器 
   unsigned char IR;//中断寄存器
   unsigned char ACR;//验收寄存器
   unsigned char AMR;//屏蔽寄存器
   unsigned char BTR0;
   unsigned char BTR1;
   unsigned char OCR;
   unsigned char TR; // 寄存器00..09
   unsigned char TxDSCR[2],TxData[8];//发送ID,数据 10..19
   unsigned char RxDSCR[2],RxData[8];//接收ID,数据 20..29
   unsigned char XX30,CDR;//31 时钟驱动 30..31
   // unsigned char XX32[0x0100-32],RST;   //复位控制 0x0100
} volatile *pcana;

#define FRAME_DATA_SIZE   10   
//每帧大小(包括TxDSCR[2]、TxData[8]或RxDSCR[2]、RxData[8])
#define IN_BUFFER_LEN     FRAME_DATA_SIZE*200  //接受缓冲区大小：100帧

static unsigned char cana_in_buffer[IN_BUFFER_LEN];   
//接受缓冲区：指通过CAN接受的数据临时存放处，用户通过read函数读取该缓冲区

static int cana_in_buf_head=0; //接受缓冲区头指针
static int cana_in_buf_tail=0; //接受缓冲区尾指针
static char cana_write_busy=0;//初始时置0，write后置1,发送中断产生时置0

static struct proc_dir_entry *interrupt_cana_file;
int cana_interruptcount = 0;
char cana_flag=0;
#include "filter.h"
//中断处理函数

static unsigned long irqt_tx=0,irqt_rx=0;

static unsigned char rgbuf[20][12];
static int prgb=0,btrig=0,btrigcount;

void interrupt_interrupt_cana(int irq, void *dev_id, struct pt_regs *regs)
{
    unsigned char ir;
    static char  into_flag=0;
    static int first=1,errcount=0;
    static unsigned char rcount = 0;
	static int gua = 0;
	int i,ccc;

    if(into_flag) return;
    into_flag=1;

    ir=pcana->IR;
	printk("IR=%x,CR=%x\n",ir,pcana->CR);
	
    if((ir&FlagRI))
    {//接受中断        
		//pcana->RxData[1] = 0x44;

	cana_in_buffer[cana_in_buf_tail]=pcana->RxDSCR[0];
        cana_in_buffer[cana_in_buf_tail+1]=pcana->RxDSCR[1];
			
//	if(IsOk(cana_in_buffer[cana_in_buf_tail])&&
//	   ((cana_in_buffer[cana_in_buf_tail+1]&0x1f)<=8))
	{
//           cana_in_buffer[cana_in_buf_tail+1]=pcana->RxDSCR[1];
           cana_in_buffer[cana_in_buf_tail+2]=pcana->RxData[0];
           cana_in_buffer[cana_in_buf_tail+3]=pcana->RxData[1];
           cana_in_buffer[cana_in_buf_tail+4]=pcana->RxData[2];
           cana_in_buffer[cana_in_buf_tail+5]=pcana->RxData[3];
           cana_in_buffer[cana_in_buf_tail+6]=pcana->RxData[4];
           cana_in_buffer[cana_in_buf_tail+7]=pcana->RxData[5];
           cana_in_buffer[cana_in_buf_tail+8]=pcana->RxData[6];
           cana_in_buffer[cana_in_buf_tail+9]=pcana->RxData[7];
           if(cana_in_buf_tail+FRAME_DATA_SIZE<IN_BUFFER_LEN)
              cana_in_buf_tail=cana_in_buf_tail+FRAME_DATA_SIZE;
	   else
	      cana_in_buf_tail=0;
	}

{
static int flagin = 0;

EnCanW;

//if(flagin==1)
//	for(flagin=0;flagin<1000;flagin++);
	
	pcana->CMR=FlagRRB;//清除接受缓冲区

//i = pcana->CMR;
DisCanW;

flagin=1;

irqt_rx++;
}
     }
     else 
     if(ir&FlagTI||ir==0xe0)//发送中断
     {
        cana_write_busy=0;
//	printk("send a");
	irqt_tx++;
     }
     else
     {
       reset_interrupt_cana();
	printk("reset a , SR=%x\n",pcana->SR);
     }

     into_flag=0;
	
	return;
}

static unsigned char scount=0;

//read响应函数
//page和count分别对应调用函数read传递的参数buf和count
//而且一次只返回一帧数据，故count和其他参数忽略
//返回值为0表示无数据，否则page返回一帧数据

static int proc_read_interrupt_cana(char *page, char **start, off_t off,
                                       int count, int *eof, void *data)
{

	printk("IRQ Times tx:%d,rx:%d , lastvalue tx:%x\n",irqt_tx,irqt_rx,scount);
	return 0;
}

int __init reset_interrupt_cana(void)
{//复为can控制器
   unsigned char b;
   int i;
   
   EnCanW;
   pcana->CR=0x0f;//开放中断
   pcana->CMR=0;
   pcana->BTR0=BTR0_Data;
   pcana->BTR1=BTR1_Data;//置波特率
   if((pcana->BTR0!=BTR0_Data)|(pcana->BTR1!=BTR1_Data))//写入回读不同
      return RESET_CAN_ERROR;
   pcana->ACR=0x07;
   pcana->AMR=0xff;
   pcana->OCR=0xfa;
   
   b=pcana->CR;
   pcana->CR=b&0xfe;
   cana_write_busy=0;
   DisCanW;
   return RESET_CAN_OK;
}

static char can_a_counts=0;//for debug

static int proc_write_interrupt_cana(struct file *file,
			const char *buffer,unsigned long count,void *data)
{
	static int loop=0,wif=1;
	int i,c=0,k;

    if(cana_write_busy) 
        return 0;
	
	pcana->TxDSCR[0]=scount;
	pcana->TxDSCR[1]=(wif&1)?0xe8:0xe2;
	for(i=0;i<8;i++)
	{
		pcana->TxData[i] = scount+i;
	}

	for(i=0;i<8;i++)
	{
		while( pcana->TxData[i]!=scount+i )
		{
			printk("error on write TxData[%d] now %x, should be %x\n",i,pcana->TxData[i],scount);

			pcana->TxData[i]=scount+i;
		}
	}
	
	scount++;
	scount&=0xf;
		
	pcana->CMR=FlagTR;

    cana_write_busy=1;
    return CAN_OK;
}

//初始化函数
static int __init init_interrupt_cana(void)
{
  int rv = 0;
  unsigned char b;

// we use bank5 for can access 
  unsigned long volatile *pp = (unsigned long volatile *)0xfc000000;
  *pp&=0xff0fffff;
  *pp|=0x00c00000;
  pp  =0xfc000018;
  *pp =0x7ff0;

EnCanW;  
pcana = cana_ADDR;
//  pcana = (struct CanControl *)ioremap_nocache(0x28000000,cana_MEM_LEN);
  pcana->CR=0x0f;
  
  // BUG---BUG
  //return EVerify;
  
  pcana->CMR=0x0;

  //printk("IR=%x,SR=%x\n",pcana->IR,pcana->SR);
  pcana->BTR1=BTR1_Data;//置波特率
  pcana->BTR0=BTR0_Data;
  //printk(" 8bit read on 8bit device:%x,%x\n",&pcana->BTR0,&pcana->BTR1);
  printk(" 8bit read on 8bit device:%x,%x\n",pcana->BTR0,pcana->BTR1);
  printk("16bit read on 8bit device:%x\n",*((unsigned short *)&pcana->BTR0));

  if((pcana->BTR0!=BTR0_Data)|(pcana->BTR1!=BTR1_Data))
  {//写入回读不同
      printk("What read is not what written  when cana initialize\n");
      iounmap((void *)pcana);
      return EVerify;
  }
  pcana->ACR=0x07;
  pcana->AMR=0xff;
  pcana->OCR=0xfa;
  b=pcana->IR;
  interrupt_cana_file = create_proc_entry("cana", 0444, NULL);
  if(interrupt_cana_file == NULL)
  {
      printk("create_proc_entry error....\n");
      iounmap((void *)pcana);  
      return -ENOMEM;
  }

  interrupt_cana_file->data = NULL;
  interrupt_cana_file->read_proc = &proc_read_interrupt_cana;
  interrupt_cana_file->write_proc = &proc_write_interrupt_cana;
  interrupt_cana_file->owner = THIS_MODULE;
  set_external_irq(INTERRUPT, EINT_FALLING_EDGE , 0 );
  rv=request_irq(INTERRUPT, interrupt_interrupt_cana,SA_INTERRUPT,
                 "cana",NULL);
  if(rv) 
  {
    printk("Can't get interrupt %d\n", INTERRUPT);
    iounmap((void *)pcana);
    remove_proc_entry("cana", NULL);
    return -1;
  }
  
  b=pcana->CR;
  pcana->CR=b&0xfe;
  printk("%s %s initialized \n",MODULE_NAME, MODULE_VERSION);
  DisCanW;
  
  Sx(1);
  
  return 0;

}

static void __exit cleanup_interrupt_cana(void)
{
  free_irq(INTERRUPT,NULL);//释放所占用中断号
  iounmap((void *)pcana);
  remove_proc_entry("cana", NULL); 
  printk(KERN_INFO "%s %s removed\n", MODULE_NAME, MODULE_VERSION);
}

module_init(init_interrupt_cana);
module_exit(cleanup_interrupt_cana);

MODULE_AUTHOR("yh");
MODULE_DESCRIPTION("interrupt_cana proc module");

EXPORT_NO_SYMBOLS;