obcanb.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 
/*************************  canb中断处理程序  *************************/
//设备名：canb，地址：D0000-D01FF

//#define _debug  //编译调试代码开关
#include <asm/io.h>
#define canb_ADDR        0xfb000000
#define canb_MEM_LEN     0x200  
//#define INTERRUPT        0x04     //使用5号中断
#define MODULE_VERSION   "1.0"
#define MODULE_NAME      "can_b_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/arch/irqs.h>

#define INTERRUPT        IRQ_EINT3     //使用5号中断
/***************************  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 *pcanb;

#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 canb_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 canb_in_buf_head=0; //接受缓冲区头指针
static int canb_in_buf_tail=0; //接受缓冲区尾指针
static char canb_write_busy=0;//初始时置0，write后置1,发送中断产生时置0

static unsigned long irqt_tx=0,irqt_rx=0;
static unsigned char rcount;
		   
static struct proc_dir_entry *interrupt_canb_file;
int canb_interruptcount = 0;
char canb_flag=0;
#include "filter.h"
//中断处理函数
void interrupt_interrupt_canb(int irq, void *dev_id, struct pt_regs *regs)
{
    unsigned char ir;
    static char into_flag=0;
	int i;
	
    if(into_flag) return;
    into_flag=1;
    ir=pcanb->IR;
    if((ir&FlagRI))
    {//接受中断        
        canb_in_buffer[canb_in_buf_tail]=pcanb->RxDSCR[0];
	canb_in_buffer[canb_in_buf_tail+1]=pcanb->RxDSCR[1];
	//if(IsOk(canb_in_buffer[canb_in_buf_tail])&&
	   //((canb_in_buffer[canb_in_buf_tail+1]&0x1f)<=8))
	   if(1)
	{
//	   canb_in_buffer[canb_in_buf_tail+1]=pcanb->RxDSCR[1];
           canb_in_buffer[canb_in_buf_tail+2]=pcanb->RxData[0];
           canb_in_buffer[canb_in_buf_tail+3]=pcanb->RxData[1];
           canb_in_buffer[canb_in_buf_tail+4]=pcanb->RxData[2];
           canb_in_buffer[canb_in_buf_tail+5]=pcanb->RxData[3];
           canb_in_buffer[canb_in_buf_tail+6]=pcanb->RxData[4];
           canb_in_buffer[canb_in_buf_tail+7]=pcanb->RxData[5];
           canb_in_buffer[canb_in_buf_tail+8]=pcanb->RxData[6];
           canb_in_buffer[canb_in_buf_tail+9]=pcanb->RxData[7];
		   
		   // a little test , depends on the sender send the same 8 bytesa
		   if(1)
		   {
		   static unsigned char lst;
		   static int first=1;
		   if(first)lst=pcanb->RxData[7];
		   first=0;
		   for(i=0;i<8;i++)if(lst+i!=pcanb->RxData[i])
		   {
			   printk("error last:%x,now:%x,%x,%x,%x,%x,%x,%x,%x\n",lst,
			   pcanb->RxData[0],pcanb->RxData[1],pcanb->RxData[2],pcanb->RxData[3],
			   pcanb->RxData[4],pcanb->RxData[5],pcanb->RxData[6],pcanb->RxData[7]);
			   lst=pcanb->RxData[0];
			   break;
		   }
		   lst++;
		   lst&=0xf;
		   rcount=lst;
			irqt_rx++;
		   }
/*		   
           if(canb_in_buf_tail+FRAME_DATA_SIZE<IN_BUFFER_LEN)
              canb_in_buf_tail=canb_in_buf_tail+FRAME_DATA_SIZE;
	   else
	      canb_in_buf_tail=0;
		  */
	}
	pcanb->CMR=FlagRRB;//清除接受缓冲区
//	i = pcanb->CMR;
     }
     else 
     if(ir&FlagTI)//发送中断
	 {
        canb_write_busy=0;
		printk("send b");
		irqt_tx++;
	}
     else
       reset_interrupt_canb();
     into_flag=0;
     return;
}
//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_canb(char *page, char **start, off_t off,
                                       int count, int *eof, void *data)
{

	printk("IRQ Times tx:%d,rx:%d , lastvalue rx:%x\n",irqt_tx,irqt_rx,rcount);
	return 0;
	
    if(canb_flag==0)
    {    
       if(canb_in_buf_head==canb_in_buf_tail)//无数据
          return CAN_READ_NO_DATA;
        page[0]=canb_in_buffer[canb_in_buf_head];       
        page[1]=canb_in_buffer[canb_in_buf_head+1];
        page[2]=canb_in_buffer[canb_in_buf_head+2];
        page[3]=canb_in_buffer[canb_in_buf_head+3];
        page[4]=canb_in_buffer[canb_in_buf_head+4];
        page[5]=canb_in_buffer[canb_in_buf_head+5];
        page[6]=canb_in_buffer[canb_in_buf_head+6];
        page[7]=canb_in_buffer[canb_in_buf_head+7];       
        page[8]=canb_in_buffer[canb_in_buf_head+8];       
        page[9]=canb_in_buffer[canb_in_buf_head+9];       
        if(canb_in_buf_head+FRAME_DATA_SIZE>=IN_BUFFER_LEN)
  	   canb_in_buf_head=0;
        else
           canb_in_buf_head=canb_in_buf_head+FRAME_DATA_SIZE;
        canb_flag=1;
    }
    else canb_flag=0;
    return CAN_OK;
}

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

//write响应函数
//buffer和count分别对应调用函数write传递的参数buf和count
//其他参数在can中断设备程序中忽略
//如果输入参数buffer[0]==CAN_DEBUG进入调试
//buffer[1]和buffer[2]分别为对应寄存器编号和将赋的值，并返回该寄存器旧值
static char can_b_counts=0;
static int proc_write_interrupt_canb(struct file *file,
			const char *buffer,unsigned long count,void *data)
{
    if(buffer[0]==CAN_RESET)
        return reset_interrupt_canb();
    if(canb_write_busy) 
    {
	if(can_b_counts>3) { reset_interrupt_canb();can_b_counts=0;}
	else can_b_counts++;
        return CAN_WRITE_BUSY;
    }
	/*
    pcanb->TxDSCR[0]=buffer[0];
    pcanb->TxDSCR[1]=buffer[1];
    pcanb->TxData[0]=buffer[2];
    pcanb->TxData[1]=buffer[3];
    pcanb->TxData[2]=buffer[4];
    pcanb->TxData[3]=buffer[5];
    pcanb->TxData[4]=buffer[6];
    pcanb->TxData[5]=buffer[7];
    pcanb->TxData[6]=buffer[8];
    pcanb->TxData[7]=buffer[9];
	*/
	
	pcanb->TxDSCR[0]=0x50;
	pcanb->TxDSCR[1]=0xe8;
    pcanb->TxData[0]=1;
    pcanb->TxData[1]=2;
    pcanb->TxData[2]=3;
    pcanb->TxData[3]=4;
    pcanb->TxData[4]=5;
    pcanb->TxData[5]=6;
    pcanb->TxData[6]=7;
    pcanb->TxData[7]=8;
	
    pcanb->CMR=FlagTR;
    canb_write_busy=1;
    return CAN_OK;
}

//初始化函数
static int __init init_interrupt_canb(void)
{
  int rv = 0;
  unsigned char b;
pcanb = canb_ADDR;  
  pcanb=(struct CanControl *)ioremap_nocache(0x29000000,canb_MEM_LEN);
  pcanb->CR=0x0f;
  pcanb->CMR=0x0;
  pcanb->BTR0=BTR0_Data;
  pcanb->BTR1=BTR1_Data;//置波特率
  if((pcanb->BTR0!=BTR0_Data)|(pcanb->BTR1!=BTR1_Data))
  {//写入回读不同
      printk("What read is not what written  when canb initialize\n");
      iounmap((void *)pcanb);
      return EVerify;
  }
  pcanb->ACR=0x07;
  pcanb->AMR=0xff;
  pcanb->OCR=0xfa;
  b=pcanb->IR;
  interrupt_canb_file = create_proc_entry("canb", 0444, NULL);
  if(interrupt_canb_file == NULL)
  {
      printk("create_proc_entry error....\n");
      iounmap((void *)pcanb);  
      return -ENOMEM;
  }

  interrupt_canb_file->data = NULL;
  interrupt_canb_file->read_proc = &proc_read_interrupt_canb;
  interrupt_canb_file->write_proc = &proc_write_interrupt_canb;
  interrupt_canb_file->owner = THIS_MODULE;
  set_external_irq(INTERRUPT,EXT_FALLING_EDGE,0);
  rv=request_irq(INTERRUPT, interrupt_interrupt_canb,SA_INTERRUPT,
                 "canb",NULL);
  if(rv) 
  {
    printk("Can't get interrupt %d\n", INTERRUPT);
    iounmap((void *)pcanb);
    remove_proc_entry("canb", NULL);
    return -1;
  }

  b=pcanb->CR;
  pcanb->CR=b&0xfe;
  printk(KERN_INFO "%s %s initialized\n",MODULE_NAME, MODULE_VERSION);

printk("init CR=%x\n",pcanb->CR);
 
  return 0;

}

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

module_init(init_interrupt_canb);
module_exit(cleanup_interrupt_canb);

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

EXPORT_NO_SYMBOLS;