vme.c

VME总线的驱动程序

/*
 * linux/drivers/char/vme.h
 *
 * Copyright (C) 2006 - 2007 yang xu
 *
 * VME Bus Control Driver 0.1
 */

#ifndef __KERNEL__
#  define __KERNEL__
#endif

#include <linux/init.h>
#include <linux/kernel.h>	/* printk() */
#include <linux/module.h> 
#include <linux/fs.h> 		/* everything... */
#include <linux/slab.h> 
#include <linux/mm.h> 
#include <linux/string.h> 
#include <asm/uaccess.h> 
#include <linux/ioport.h>
#include <linux/pci.h>
#include <asm/arch/AT91RM9200_SYS.h>
#include <asm/arch/AT91RM9200.h>
#include <asm/arch/pio.h>
#include <asm/irq.h>
#include <linux/ioctl.h>	/* O_ACCMODE */
#include <linux/types.h>	/* size_t */
#include <asm/io.h>
#include "vme.h"

DECLARE_WAIT_QUEUE_HEAD(vme_queue);

/* The declaration of some function prototypes */

static int vme_open(struct inode *inode, struct file *filp);
static int vme_release(struct inode *inode, struct file *filp) ;
static ssize_t vme_write(struct file *filp, const int *buf, size_t count, loff_t *offp) ;
static ssize_t vme_read(struct file *filp, int *buf, size_t count, loff_t *offp) ;
static int vme_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long addr);
static loff_t vme_seek(struct file *filp,loff_t off, int whence);
static void vme_interrupt(int irq,void *dev_id,struct pt_regs *regs);
static void vme_bus_operation(void);
     
struct file_operations vme_fops=
{
	owner:		THIS_MODULE,
	read:		vme_read,
	write:		vme_write,
	open:		vme_open,
	release:	vme_release,
	llseek:		vme_seek,
    ioctl:      vme_ioctl,
};


static loff_t vme_seek(struct file *filp,loff_t off, int whence) {

	vme_RegAddr_temp = vme_RegAddr +(vme_off/4);
    return vme_RegAddr_temp;
}
static int vme_open(struct inode *inode, struct file *filp) 
{ 	
	//int result;
	//result = request_irq(IRQ_NUMBER,vme_interrupt,SA_INTERRUPT,"VME",NULL);
	//if (result) printk(KERN_INFO "vme : can't get assigned irq %i \n",IRQ_NUMBER); 
	try_module_get(THIS_MODULE);	//for 2.6
	// MOD_INC_USE_COUNT; 
	return 0; 
} 
static int vme_release(struct inode *inode, struct file *filp) 
{ 
	// free interrupt 
	//free_irq(IRQ_NUMBER,NULL);  
	module_put(THIS_MODULE);	// for 2.6
	//MOD_DEC_USE_COUNT;
	return 0; 
} 

static ssize_t vme_write(struct file *filp, const int *buf, size_t count, loff_t *offp) 
{ 	
	int i;
	switch (count)
	{
		case 0: printk(KERN_INFO "vme_write The count must be an integer !\n");break; 

		case 1: *(vme_RegAddr+VME_CSR_OFF/4)=*buf & 0xFFCFFFFF ;break;

		case 2: *(vme_RegAddr+VME_CSR_OFF/4)=*(buf++) & 0xFFCFFFFF;
				*(vme_RegAddr+VME_ADDR_OFF/4)=*(buf);
				addr_tmp=*buf;
				break;

		/* if burst on is set, address need't to add itself */
		default:if ((*buf & 0x40000000)!=0) 
				{
					vme_bus_operation();	/* bus request, bus occupy */

					*(vme_RegAddr+VME_CSR_OFF/4)=*(buf++);
					addr_tmp=*(buf);
					*(vme_RegAddr+VME_ADDR_OFF/4)=*(buf++);

					for (i=0;i<count-2;i++)
					{
						*(unsigned short *)(vme_RegAddr+VME_DATA_OFF/4)=*(buf++);		
						while ((*(vme_RegAddr+VME_CSR_OFF/4) & 0x80000)==0) NULL;
						*(vme_RegAddr+VME_ADDR_OFF/4)=addr_tmp;
					}
				}
				else 
				{
					vme_bus_operation();	/* bus request, bus occupy */

					*(vme_RegAddr+VME_CSR_OFF/4)=*(buf++);
					addr_tmp=*(buf);
					*(vme_RegAddr+VME_ADDR_OFF/4)=*(buf++);

					for (i=0;i<count-2;i++)
					{
						*(unsigned short *)(vme_RegAddr+VME_DATA_OFF/4)=*(buf++);		
						while ((*(vme_RegAddr+VME_CSR_OFF/4) & 0x80000)==0) NULL;
						addr_tmp=addr_tmp+2;
						*(vme_RegAddr+VME_ADDR_OFF/4)=addr_tmp;
					}
		      	}
				*( vme_RegAddr+VME_CSRL_OFF)=*( vme_RegAddr+VME_CSRL_OFF) & 0xFFFFBFFF; /* bus release */
	}
	return count; 
} 

static ssize_t vme_read(struct file *filp, int *buf, size_t count, loff_t *offp) 
{ 
	int i;
	unsigned short data;
	switch (count)
	{
	 case 0: interruptible_sleep_on(&vme_queue);
		
			 vme_bus_operation();	/* bus request, bus occupy */
			 
			 /* the following may be need atomic process */
			 /* send READ cmd */
			 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) & 0xFFCFFFFF;
			 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) | 0x00200000;

			 /* waiting for ACK and return data */
		     while ((*( vme_RegAddr+VME_CSR_OFF)& 0x80000)==0) NULL;
			 data = *((unsigned short *)(vme_RegAddr+VME_DATA_OFF/4));
			 *buf = (int)data;

			 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) & 0xFFFFFFFD; /* clear iack; */

			 *( vme_RegAddr+VME_CSRL_OFF)=*( vme_RegAddr+VME_CSRL_OFF) & 0xFFFFBFFF; /* bus release */
			 break; 

	 case 1: *buf = *(vme_RegAddr+VME_CSR_OFF/4);
			 break;

	 case 2: *(buf++) = *(vme_RegAddr+VME_CSR_OFF/4);
			 *(buf++) = *(vme_RegAddr+VME_ADDR_OFF/4);
		     break;

			 /* if burst on is set, address need't to add itself */
	 default:if ((*buf & 0x40000000)!=0) 
			 {
			   vme_bus_operation();	/* bus request, bus occupy */

			  /* clear write and read bit */
			  *(vme_RegAddr+VME_CSR_OFF/4)=*(buf++) & 0xFFCFFFFF;
			  addr_tmp=*(buf);
			  *(vme_RegAddr+VME_ADDR_OFF/4)=*(buf);
			  buf--;

			  /* read CSR and ADDR for check */
			  *(buf++) = *(vme_RegAddr+VME_CSR_OFF/4);
			  *(buf++) = *(vme_RegAddr+VME_ADDR_OFF/4);

			  for(i=0;i<count-2;i++)
				{
				 *(vme_RegAddr+VME_ADDR_OFF/4)=addr_tmp;
				 
				 /* send READ cmd */
				 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) & 0xFFCFFFFF;
				 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) | 0x00200000;
	
				 /* waiting for ACK and return data */
				 while ((*( vme_RegAddr+VME_CSR_OFF)& 0x80000)==0) NULL;
				 data = *((unsigned short *)(vme_RegAddr+VME_DATA_OFF/4));
				 *(buf++) = (int)data;
				}
			  }
			else 
			{
			  vme_bus_operation();	/* bus request, bus occupy */

			  /* clear write and read bit */
			  *(vme_RegAddr+VME_CSR_OFF/4)=*(buf++) & 0xFFCFFFFF;
			  addr_tmp=*(buf);
			  *(vme_RegAddr+VME_ADDR_OFF/4)=*(buf);
			  buf--;

			  /* read CSR and ADDR for check */
			  *(buf++) = *(vme_RegAddr+VME_CSR_OFF/4);
			  *(buf++) = *(vme_RegAddr+VME_ADDR_OFF/4);

			  for(i=0;i<count-2;i++)
				{
				 *(vme_RegAddr+VME_ADDR_OFF/4)=addr_tmp;
				 addr_tmp=addr_tmp+2;

				 /* send READ cmd */
				 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) & 0xFFCFFFFF;
				 *(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) | 0x00200000;

				 /* waiting for ACK and return data */
				 while ((*( vme_RegAddr+VME_CSR_OFF)& 0x80000)==0) NULL;
				 data = *((unsigned short *)(vme_RegAddr+VME_DATA_OFF/4));
				 *(buf++) = (int)data;
				}
			 }
			 *( vme_RegAddr+VME_CSRL_OFF)=*( vme_RegAddr+VME_CSRL_OFF) & 0xFFFFBFFF;		/* bus release */
		}
	
	return count; 
} 

static int vme_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long addr)
{	
	switch(cmd){
		case 1: *(vme_RegAddr+VME_CSR_OFF/4)=(int) addr & 0xFFCFFFFF ;
		        break;
		case 2: *(vme_RegAddr+VME_ADDR_OFF/4)=(int) addr;
			addr_tmp=(int) addr;
			break;
		case 4: *(vme_RegAddr+VME_DATA_OFF/4)=(short)addr;
			break;
		default:printk(KERN_INFO "vme_ioctl: Can't identify the CMD!\n"); 
	}	
return 1;	
}
// interrupt handling,now do nothing
static void vme_interrupt(int irq,void *dev_id,struct pt_regs *regs)
{	
	*(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) | 0x00000002;	/* set iack; */

	*(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) & 0xFFFFFFC2;	/* close interrupt */

	/* send interrupt vector to address register;*/
	*(vme_RegAddr+VME_ADDR_OFF/4)= (*(vme_RegAddr+VME_CSR_OFF/4) & 0x000000c0) >> 5;

	*(vme_RegAddr+VME_CSR_OFF/4)=*(vme_RegAddr+VME_CSR_OFF/4) | 0x0000003d;	/* enable interrupt */

	wake_up_interruptible(&vme_queue);	/* waking up all read processs */
	
}

static void vme_bus_operation(void)
{
	while ((*( vme_RegAddr+VME_CSRL_OFF/4) & 0x8000) != 0) NULL; /* check bus state */
		
	*( vme_RegAddr+VME_CSRL_OFF)=*( vme_RegAddr+VME_CSRL_OFF) | 0x00000100; /* bus request 0 */
		
	while ((*( vme_RegAddr+VME_CSRL_OFF) & 0x00000200) == 0 ) NULL; /* bus allow */
		
	*( vme_RegAddr+VME_CSRL_OFF)=*( vme_RegAddr+VME_CSRL_OFF) | 0x00004000; /* bus 占用 */
}

static int __init init_vme(void)
{ 
	static int result;
    AT91_SYS->EBI_SMC2_CSR[7] = 0x10003182;		
	
//-----------------------------------------------------------------------------------------------------------------
	if (!request_mem_region(VME_PHYSICAL_REG_ADDR,VME_PHYSICAL_REG_SIZE, "VME_DRIVER"))
    		printk("Error request mem \n");
	vme_RegAddr  = (unsigned int*) ioremap_nocache(VME_PHYSICAL_REG_ADDR,VME_PHYSICAL_REG_SIZE);
	
	 //*(unsigned int *)( vme_RegAddr+VME_CSR_OFF)=0x3e09003d;
	 *(unsigned int *)(vme_RegAddr+ VME_CSR_OFF) =0x3e190000;

	// enable IRQ5;
	//enable_irq(IRQ_NUMBER);

	printk("vme:Phys Reg address:%X  \n", vme_RegAddr);
	
	if (!vme_RegAddr)
    		printk("vme_init: ioremap() returned NULL\n");
    		
//-----------------------------------------------------------------------------------------------------------------
	register_chrdev(MAJOR_NUM, "vme", &vme_fops); 
	
	result = request_irq(IRQ_NUMBER,vme_interrupt,SA_INTERRUPT,"VME",NULL);
	if (result) printk(KERN_INFO "vme : can't get assigned irq %i \n",IRQ_NUMBER); 

	printk("vme device installed.\n");
	
	return 0; 
} 

static void __exit exit_vme(void)
{
	/* free interrupt */
	free_irq(IRQ_NUMBER,NULL);  
	printk("vme device uninstalled.\n"); 
} 

module_init(init_vme);
module_exit(exit_vme);