sst16.c

arm7,44b0芯片的blob程序,适用于学嵌入式linux的新手.

/*
 * sst16.c: sst 16 bit (2M x 16 bit) flash driver
 *
 * Copyright (C) 2002  tpu ([e-mail])
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ident "$Id: sst16.c,v 1.4 2002/01/02 01:23:18 tpu Exp $"

#ifdef HAVE_CONFIG_H
# include <blob/config.h>
#endif

#include <blob/errno.h>
#include <blob/flash.h>
#include <blob/util.h>
#include <blob/serial.h>

#define READ_ARRAY 	0x0000f0f0
#define FLASH_ADDR1 	0x0000aaaa
#define FLASH_ADDR2 	0x00005554
#define UNLOCK1 	0x0000aaaa
#define UNLOCK2 	0x00005555
#define ERASE_SETUP 	0x00008080
#define ERASE_CONFIRM 	0x00003030
#define PGM_SETUP	0x0000a0a0

static void check_data_polling(u16 *addr)
{
	int timeout;
       	u16 data;

	timeout = 0;
	while(timeout<0x0007ffff){
		data = *addr;
		barrier();
		if((data&0x80) == 0x80)
			break;
		timeout ++;
	}
}

static void check_toggle_ready(u16 *addr)
{ 
	u16 currdata, predata;
	int timeout;

	timeout = 0;
	predata = *addr;
	barrier();
	predata &= 0x40;
	while(timeout<0x7ffff){
		currdata = *addr;
		barrier();
		currdata &= 0x40;
		if(predata == currdata)
			break;
		predata = currdata;
		timeout ++;
	}
}

static int flash_erase_sst16(u32 *addr)
{
	/* clear */
	*(u16 *)FLASH_ADDR1 = READ_ARRAY;
	barrier();
	
	/* prepare for erase */
	*(u16 *)FLASH_ADDR1 = UNLOCK1;
	barrier();
	*(u16 *)FLASH_ADDR2 = UNLOCK2;
	barrier();
	*(u16 *)FLASH_ADDR1 = ERASE_SETUP;
	barrier();

        /* erase command */
        *(u16 *)FLASH_ADDR1 = UNLOCK1;
        barrier();
        *(u16 *)FLASH_ADDR2 = UNLOCK2;
        barrier();
        *(u16 *)addr = ERASE_CONFIRM;

	check_data_polling((u16 *)addr);
	return 0;
}

static int do_write_16(u16 *addr, u16 *data)
{
	*(u16 *)FLASH_ADDR1 = UNLOCK1;
	barrier();
	*(u16 *)FLASH_ADDR2 = UNLOCK2;
	barrier();
	*(u16 *)FLASH_ADDR1 = PGM_SETUP;
	barrier();
	
	*addr = *data;
	barrier();

	check_toggle_ready(addr);
	return 0;
}


static int flash_write_sst16(u32 *dst, const u32* src)
{
	u16 *addr, *data;

	addr = (u16 *)dst;
	data = (u16 *)src;

	/* clear */
	*(u16 *)FLASH_ADDR1 = READ_ARRAY;
	barrier();

	do_write_16(addr, data);
	addr ++;
	data ++;
	do_write_16(addr, data);

	return 0;
}

static int flash_lock_block_sst16(u32 *blockStart)
{
	return 0;
}

static int flash_unlock_block_sst16(u32 *blockStart)
{
	return 0;
}

static int flash_query_block_lock_sst16(u32 *blockStart)
{
	return 0;
}

/* flash driver structure */
flash_driver_t sst16_flash_driver = {
	erase:			flash_erase_sst16,
	write:			flash_write_sst16,
	lock_block:		flash_lock_block_sst16,
	unlock_block:		flash_unlock_block_sst16,
	query_block_lock:	flash_query_block_lock_sst16
};