led_timer.c

基于linux操作系统ATMELARM9200 开发平台的LED演示程序

/***********************************************************************
 *
 * (C) Copyright 2004,12
 * 
 * Himai tech
 * All rights left.
 *
 *
 * a simple Device Driver for HM901ESP led device
 *
 * Can be loaded as module
 *
 * $Id: led.c,v 1.1 2004/12/15  $
 *
 ***********************************************************************/

/*
 * 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 <linux/init.h>		/* for __initfunc		*/
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/interrupt.h>    
#include <linux/timer.h>
#include <asm/io.h>        	/* for ioremap                  */
#include <asm/arch/hardware.h>	/* atmel RM9200           	*/      
#include <asm/arch/pio.h>




//#undef	DEBUG
#define	DEBUG		1

#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


MODULE_LICENSE("GPL");


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


#define SUCCESS 	0

#define TIMER_INTERVAL  300        /* timer interval ms */

/* see ATMEL RM9200 datasheet */
#define AT91C_BASE_PMC			0xFFFFFC00     /* PMC controller base address */
#define PMC_MEM_LEN                	0x70     
#define PMC_PCER_OFF                 	0x10      
#define PMC_PCSR_OFF                	0x18

#define AT91C_BASE_PIOB  		0xFFFFF600     /* PIO-B base address */
#define PIO_MEM_LEN               	0xB0
#define PIO_PER_OFF                    	0x00
#define PIO_OER_OFF			0x10
#define PIO_SODR_OFF			0x30
#define PIO_CODR_OFF      		0x34
#define PIO_ODSR_OFF			0x38


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


struct timer_list led_timer;

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

static void  *pmc_base, *piob_base;


void led_light(void* data)
{

	if(led_data  == 1)   /*turn on led*/
	{    
	  	writel (AT91C_PIO_PB12, piob_base + PIO_CODR_OFF);
		led_data = 0;
	}
	else             /*turn off led*/
	{
	        writel (AT91C_PIO_PB12, piob_base +  PIO_SODR_OFF);
		led_data = 1;
	}
	

	init_timer(&led_timer);
	led_timer.function = (void (*)(unsigned long))led_light;
        led_timer.data     = (unsigned long)&led_data;
        led_timer.expires  = TIMER_INTERVAL * HZ /1000;

	mod_timer(&led_timer, jiffies + TIMER_INTERVAL * HZ/1000);
	
}


/*
 * Initialize the driver - Register the character device
 */
static int __init led_init(void)
{

  unsigned int i;

	/* get the remmapped controller base address register */
	pmc_base = ioremap_nocache(AT91C_BASE_PMC, PMC_MEM_LEN);
          
        /* enable PIOB power */
        writel (1 << AT91C_ID_PIOB, pmc_base + PMC_PCER_OFF);  
	i = readl(pmc_base + PMC_PCSR_OFF);

	printk ("pmc_base = 0x%08X\n", (int) pmc_base);
	printk ("PCSR     = 0x%08X\n", i);
	iounmap (pmc_base);

	/* set PB12 output */
	piob_base = ioremap_nocache(AT91C_BASE_PIOB, PIO_MEM_LEN);
	writel (AT91C_PIO_PB12, piob_base + PIO_PER_OFF); 
	writel (AT91C_PIO_PB12, piob_base + PIO_OER_OFF); 

	printk ("piob_base = 0x%08X\n", (int) piob_base);

	writel (AT91C_PIO_PB12, piob_base + PIO_CODR_OFF);


	led_data = 1;
	
	init_timer(&led_timer);
	led_timer.function = (void(*)(unsigned long))led_light;
	led_timer.data     = (unsigned long)&led_data;
	led_timer.expires  = jiffies + TIMER_INTERVAL * HZ /1000;
	add_timer(&led_timer);

	return 0;
}

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

#ifdef MODULE

/*
 * Cleanup - unregister the appropriate file from /proc
 */
static void __exit cleanup_led_module (void)
{

	/*turn off led */
        writel (AT91C_PIO_PB12, piob_base + PIO_SODR_OFF);

	iounmap (piob_base);
	debugk ("iounmap: piob_base = 0x%08x\n", (int) piob_base);

	del_timer(&led_timer);	
	return;
}

module_init(led_init);
module_exit(cleanup_led_module);

MODULE_AUTHOR("Himai");
MODULE_DESCRIPTION("led driver for HM901ESP");

#endif	/* MODULE */