led_scheduler.c

这是motorola公司的powerpc芯片上的嵌入式linux上的驱动程序和测试程序

/***********************************************************************
 *
 * (C) Copyright 2002,12
 * 
 * Qi zhaoling 
 * All rights left.
 *
 *
 * a simple Device Driver for UT850GE led device
 *
 * Can be loaded as module
 *
 * $Id: led.c,v 1.1 2000/01/14 16:28:49 wd Exp $
 *
 ***********************************************************************/

/*
 * Standard in kernel modules
 */
#include <linux/kernel.h>	/* We're doing kernel work	*/
#include <linux/module.h>	/* Specifically, a module	*/
#include <asm/uaccess.h>	/* for put_user			*/
#include <asm/init.h>		/* for __initfunc		*/
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/tqueue.h>
#include <linux/interrupt.h>    
#include <asm/8xx_immap.h>
#include <asm/mpc8xx.h>


static volatile iop8xx_t *iop_p = 0;   /*i/o port point of UT850GE*/

#undef	DEBUG

#ifdef	DEBUG
# define debugk(fmt,args...)	printk(fmt ,##args)
#else
# define debugk(fmt,args...)
#endif

/*
 * Deal with CONFIG_MODVERSIONS
 */
#if CONFIG_MODVERSIONS==1
/* # define MODVERSIONS */
# include <linux/modversions.h>
#endif


#ifndef KERNEL_VERSION
# define KERNEL_VERSION(a,b,c)	((a)*65536+(b)*256+(c))
#endif

#define	DEBUG	1
#define SUCCESS 0


#define MAX_LED 2
#define LINK_LED 0
#define ALARM_LED 1

static ushort  UTLed[MAX_LED] = {0x1000, 0x0800};


/*
 * Prototypes
 */
int led_init (void );

int init_module(void);
void cleanup_module(void);


struct tq_struct led_task;        /* global: initialized to zero */

static int led_data;  /*1: light   0:dis-light */

void led_light(void* data)
{
	volatile iop8xx_t *cp = iop_p;

	if(led_data  == 1)   /*turn on led*/
	{    
		cp->iop_pddat &= ~UTLed[ALARM_LED];
		cp->iop_pddat &= ~UTLed[LINK_LED];
		led_data = 0;
	}
	else             /*turn off led*/
	{
		cp->iop_pddat |= UTLed[ALARM_LED];
		cp->iop_pddat |= UTLed[LINK_LED];
		led_data = 1;
	}
	
	current->state = TASK_UNINTERRUPTIBLE;
	schedule_timeout(1 + 100*HZ /1000);
	schedule_task(&led_task);
}


/*
 * Initialize the driver - Register the character device
 */
int led_init(void)
{
	volatile iop8xx_t *cp;	

	if (!iop_p) 
	{		/* init i/o port ptr */
		unsigned long immr;

		asm( "mfspr %0,638": "=r"(immr) : );
		immr &= 0xFFFF0000;
		iop_p = (iop8xx_t *)&((volatile immap_t *)immr)->im_ioport;
	}
	
	cp = iop_p;

	cp->iop_pdpar &= ~UTLed[LINK_LED];  
	cp->iop_pddir |=  UTLed[LINK_LED];  /*set to output IO*/

	cp->iop_pdpar &= ~UTLed[ALARM_LED];  
	cp->iop_pddir |=  UTLed[ALARM_LED]; /*set to output IO*/

	led_data = 1;
	led_task.routine = led_light;
	led_task.data    = (void*) &led_data;
	led_task.sync    = 0;

	schedule_task(&led_task);
	return 0;
}

/******************************
 **** Module Declarations *****
 **************************** */

#ifdef MODULE
/*
 * Initialize the module
 */
int init_module (void)
{
	return led_init();
}

/*
 * Cleanup - unregister the appropriate file from /proc
 */
void cleanup_module (void)
{
        volatile iop8xx_t *cp = iop_p;

	/*turn off led */
        cp->iop_pddat |= UTLed[ALARM_LED];
        cp->iop_pddat |= UTLed[LINK_LED];

	return;
}

#endif	/* MODULE */