blob: 4042e8bf9677b6cd70a0d3ffe1496a41037b97b6 [file] [log] [blame]
/*
* sst28sf040.c: driver for SST28SF040C flash models.
*
*
* Copyright 2000 Silicon Integrated System Corporation
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*
* Reference:
* 4 MEgabit (512K x 8) SuperFlash EEPROM, SST28SF040 data sheet
*
* $Id$
*/
#include "flash.h"
#include "jedec.h"
#define AUTO_PG_ERASE1 0x20
#define AUTO_PG_ERASE2 0xD0
#define AUTO_PGRM 0x10
#define CHIP_ERASE 0x30
#define RESET 0xFF
#define READ_ID 0x90
static __inline__ void protect_28sf040 (volatile char * bios)
{
/* ask compiler not to optimize this */
volatile unsigned char tmp;
tmp = *(volatile unsigned char *) (bios + 0x1823);
tmp = *(volatile unsigned char *) (bios + 0x1820);
tmp = *(volatile unsigned char *) (bios + 0x1822);
tmp = *(volatile unsigned char *) (bios + 0x0418);
tmp = *(volatile unsigned char *) (bios + 0x041B);
tmp = *(volatile unsigned char *) (bios + 0x0419);
tmp = *(volatile unsigned char *) (bios + 0x040A);
}
static __inline__ void unprotect_28sf040 (volatile char * bios)
{
/* ask compiler not to optimize this */
volatile unsigned char tmp;
tmp = *(volatile unsigned char *) (bios + 0x1823);
tmp = *(volatile unsigned char *) (bios + 0x1820);
tmp = *(volatile unsigned char *) (bios + 0x1822);
tmp = *(volatile unsigned char *) (bios + 0x0418);
tmp = *(volatile unsigned char *) (bios + 0x041B);
tmp = *(volatile unsigned char *) (bios + 0x0419);
tmp = *(volatile unsigned char *) (bios + 0x041A);
}
static __inline__ erase_sector_28sf040 (volatile char * bios, unsigned long address)
{
*bios = AUTO_PG_ERASE1;
*(bios + address) = AUTO_PG_ERASE2;
/* wait for Toggle bit ready */
toggle_ready_jedec(bios);
}
static __inline__ write_sector_28sf040(volatile char * bios, unsigned char * src,
volatile unsigned char * dst, unsigned int page_size)
{
int i;
for (i = 0; i < page_size; i++) {
/* transfer data from source to destination */
if (*src == 0xFF) {
dst++, src++;
/* If the data is 0xFF, don't program it */
continue;
}
/*issue AUTO PROGRAM command */
*dst = AUTO_PGRM;
*dst++ = *src++;
/* wait for Toggle bit ready */
toggle_ready_jedec(bios);
}
}
int probe_28sf040 (struct flashchip * flash)
{
volatile char * bios = flash->virt_addr;
unsigned char id1, id2, tmp;
/* save the value at the beginning of the Flash */
tmp = *bios;
*bios = RESET;
myusec_delay(10);
*bios = READ_ID;
myusec_delay(10);
id1 = *(volatile unsigned char *) bios;
myusec_delay(10);
id2 = *(volatile unsigned char *) (bios + 0x01);
*bios = RESET;
myusec_delay(10);
printf(__FUNCTION__ "id1 %d, id2 %d\n", id1, id2);
if (id1 == flash->manufacture_id && id2 == flash->model_id)
return 1;
/* if there is no SST28SF040, restore the original value */
*bios = tmp;
return 0;
}
int erase_28sf040 (struct flashchip * flash)
{
volatile char * bios = flash->virt_addr;
unprotect_28sf040 (bios);
*bios = CHIP_ERASE;
*bios = CHIP_ERASE;
protect_28sf040 (bios);
myusec_delay(10);
toggle_ready_jedec(bios);
}
int write_28sf040 (struct flashchip * flash, char * buf)
{
int i;
int total_size = flash->total_size * 1024, page_size = flash->page_size;
volatile char * bios = flash->virt_addr;
unprotect_28sf040 (bios);
printf ("Programming Page: ");
for (i = 0; i < total_size/page_size; i++) {
/* erase the page before programming */
erase_sector_28sf040(bios, i * page_size);
/* write to the sector */
printf ("%04d at address: 0x%08x", i, i * page_size);
write_sector_28sf040(bios, buf + i * page_size, bios + i * page_size,
page_size);
printf ("\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b");
}
printf("\n");
protect_28sf040 (bios);
}