学步园

最近我利用网上的一个并口驱动程序，增加自己需要的内容，利用并口电压来产生中断，但是出现了问题，困扰了好久得不到解决，所以放上来求大家帮助。

代码奉上：

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/interrupt.h>

#include <asm/io.h> /* outb */
#define MODULE_VERSION "1.0"
#define MODULE_NAME "interrupt_latency_x86"

int interruptcount = 0;
struct timeval tv1, tv2; /* do_gettimeofday fills these */

#define SPPDATAPORT         0x378
#define SPPSTATUSPORT       (SPPDATAPORT + 1)
#define SPPCONTROLPORT      (SPPDATAPORT + 2)
#define SSPINTERRUPTENABLE  0x10

#define INTERRUPT 7

static struct proc_dir_entry *interrupt_latency_file;

/*
 * function interrupt_interrupt_latency
 * This function is the interrupt handler for interrupt 7. It sets the tv2
 * structure using do_gettimeofday. It then deasserts D7.
 */
void interrupt_interrupt_latency(int irq, void *dev_id, struct pt_regs *regs)
{
  do_gettimeofday(&tv2);
  outb(0x00,SPPDATAPORT); /* deassert the interrupt signal */
  interruptcount++;
}

/*
 * function proc_read_interrupt_latency
 * The kernel executes this function when a read operation occurs on
 * /proc/interrupt_latency. This function sets the tv1 structure. It asserts
 * D7 which should immediately cause interrupt 7 to occur. The handler
 * records tv2 and deasserts D7. This function returns the time differential
 * between tv2 and tv1.
 */
static int proc_read_interrupt_latency(char *page, char **start, off_t off,int count, int *eof, void *data)
{
  int len;
  do_gettimeofday(&tv1);
  outb(0x80,SPPDATAPORT); /* assert the interrupt signal */

  len = sprintf(page, "Start %9i.%06i\nFinish  %9i.%06i\nLatency %17i\n\Count %19i\n",(int)tv1.tv_sec, (int)tv1.tv_usec,
                (int)tv2.tv_sec, (int)tv2.tv_usec, (int)(tv2.tv_usec - tv1.tv_usec),interruptcount);

  return len;
}

/*
 * function init_interrupt_latency
 * This function creates the /proc directory entry interrupt_latency. It
 * also configures the parallel port then requests interrupt 7 from Linux.
 */
static int __init init_interrupt_latency(void)
{
  int rv = 0;

  interrupt_latency_file = create_proc_entry("interrupt_latency", 0444, NULL);
  if(interrupt_latency_file == NULL){
    return -ENOMEM;
  }
  interrupt_latency_file->data = NULL;
  interrupt_latency_file->read_proc = &proc_read_interrupt_latency;
  interrupt_latency_file->write_proc = NULL;
 

  /* request interrupt from linux */
  rv = request_irq(INTERRUPT, interrupt_interrupt_latency, 0, "interrupt_latency",NULL);
  printk("rv value is %d",rv);
  if(rv){
    printk("Can't get interrupt %d\n", INTERRUPT);
    /* remove the proc entry on error */
    remove_proc_entry("interrupt_latency", NULL);
    printk("i am in rv remove\n");
  }

/* enable parallel port interrupt generation */
  outb(SSPINTERRUPTENABLE,SPPCONTROLPORT);

/* deassert the interrupt signal */
  outb(0x00,SPPDATAPORT);

/* everything initialized */
  printk(KERN_INFO "%s %s initialized\n",MODULE_NAME, MODULE_VERSION);
  return 0;

}


/*
 * function cleanup_interrupt_latency
 * This function frees interrupt 7 then removes the /proc directory entry
 * interrupt_latency.
 */
static void __exit cleanup_interrupt_latency(void)
{
/* disable parallel port interrupt reporting */
  outb(0x00,SPPCONTROLPORT);

/* free the interrupt */
  free_irq(INTERRUPT,NULL);

  remove_proc_entry("interrupt_latency", NULL);

  printk(KERN_INFO "%s %s removed\n", MODULE_NAME, MODULE_VERSION);
}

module_init(init_interrupt_latency);
module_exit(cleanup_interrupt_latency);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("ZXL");
MODULE_DESCRIPTION("interrupt_latency proc module");

EXPORT_NO_SYMBOLS;

Makefile：

obj-m := interrupt_latency_x86.o

KDIR := /lib/modules/2.6.33.7.2-rt30/build

PWD := $(shell pwd)

all:
        make -C $(KDIR) M=$(PWD) modules

clean:
        rm -f *.o *.ko *.mod.c Modules.symvers modules.order 

编译成功后，insmod，dmesg后均正常，但是cat /proc/interrupt_latency后，就只有tv1的开始时间，没有结束时间，也就是说中断没有被触发，但是代码中已经在pin口写高地址了，不知道什么问题，有待解决！！！
PS:我是在i386的系统上运行的.

修改：

ps1.要把并口的pin9和pin10用线连起来，这是目前能改进的地方，但是发现还是不行啊。。。。4.26

ps2.在系统设置中，把parport打开，卸载了系统自带的parport程序，但是还是不能触发中断！。。。5.2

ps3.最近做调试，发现并口电压不能“拉低”，不知道什么原因？。。。5.8