mmc_s3c2440.c

来自「mmc 方式通讯的在CPU PXA270下的WINCE 5驱动」· C语言 代码 · 共 80 行

/* 
 * 2002 (C) Copyrigt SAMSUMNG ELECTRONICS 
 *           SW.LEE <[e-mail]>
 * 
 * 	    Low-level MMC functions for the S3CXX
 *
 * Copyright 2002 Hewlett-Packard Company
 *
 * Use consistent with the GNU GPL is permitted,
 * provided that this copyright notice is
 * preserved in its entirety in all copies and derived works.
 *
 * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
 * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
 * FITNESS FOR ANY PARTICULAR PURPOSE.
 *
 * Many thanks to Alessandro Rubini and Jonathan Corbet!
 *
 * Author:  Andrew Christian
 *          6 May 2002
 */


#include <linux/module.h>
#include <linux/version.h>

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>

#include <asm/irq.h>       
#include <asm/io.h>       
#include <asm/unaligned.h>

#include <asm/arch/hardware.h>
#include <linux/mmc/mmc_ll.h>
#include "s3c_mmc.h"

#define SD_GPIO_CD		GPIO_nCD_SD	
#define SD_IRQ_CD		IRQ_nCD_SD

static __inline__ void mmc_delay(void) {mdelay(100);}

/*******
 * Prototype 
 *  static int  mmc_s3c_slot_is_empty (int slot)
 * Purpose:
  * Entry
 * Exit
 *        1  : slot is empty
 *        0  : occupied
 * Exceptions:
 *****************************************************/
static int  mmc_s3c2440_slot_is_empty (struct s3c_mmc_lowlevel *lowlevel)
{
	int retval;
	set_gpio_ctrl(SD_GPIO_CD | GPIO_PULLUP_DIS | GPIO_MODE_IN);
	mmc_delay();		/* I amn' sure of how long time to*/
    	retval = read_gpio_bit(SD_GPIO_CD);
    	set_gpio_ctrl(SD_GPIO_CD | GPIO_PULLUP_DIS | GPIO_MODE_EINT);

	return retval;
}



struct s3c_mmc_lowlevel s3c2440_mmc_lowlevel = {
	.name = "s3c2440_mmc",
	.sdi_irq = IRQ_SDI,
	.detect_irq = SD_IRQ_CD,
	.detect_irq_edge = EXT_BOTH_EDGES,
	.detect_irq_pullup = GPIO_PULLUP_DIS,
	.sdi_gpio_cd = SD_GPIO_CD,
	.sdi_clock = CLKCON_SDI,
	.slot_is_empty = mmc_s3c2440_slot_is_empty
};