flash.c

嵌入式试验箱S3C2410的bootloader源代码

	case INTEL_ID_28F640J3A:
		info->flash_id += FLASH_28F640J3A;
		info->sector_count = 64;
		info->size = 0x00800000 * 2;
		break;				/* => 16 MB		*/

	case INTEL_ID_28F128J3A:
		info->flash_id += FLASH_28F128J3A;
		info->sector_count = 128;
		info->size = 0x01000000 * 2;
		break;				/* => 32 MB		*/

	default:
		info->flash_id = FLASH_UNKNOWN;
		addr[0] = 0x00FF00FF;		/* restore read mode */
		return (0);			/* => no or unknown flash */

	}

	if (info->sector_count > CFG_MAX_FLASH_SECT) {
		printf ("** ERROR: sector count %d > max (%d) **\n",
			info->sector_count, CFG_MAX_FLASH_SECT);
		info->sector_count = CFG_MAX_FLASH_SECT;
	}

	addr[0] = 0x00FF00FF;		/* restore read mode */

	return (info->size);
}


/*-----------------------------------------------------------------------
 */

int	flash_erase (flash_info_t *info, int s_first, int s_last)
{
	int flag, prot, sect;
	ulong start, now, last;

	debug ("flash_erase: first: %d last: %d\n", s_first, s_last);

	if ((s_first < 0) || (s_first > s_last)) {
		if (info->flash_id == FLASH_UNKNOWN) {
			printf ("- missing\n");
		} else {
			printf ("- no sectors to erase\n");
		}
		return 1;
	}

	if ((info->flash_id & FLASH_VENDMASK) != FLASH_MAN_INTEL) {
		printf ("Can erase only Intel flash types - aborted\n");
		return 1;
	}

	prot = 0;
	for (sect=s_first; sect<=s_last; ++sect) {
		if (info->protect[sect]) {
			prot++;
		}
	}

	if (prot) {
		printf ("- Warning: %d protected sectors will not be erased!\n",
			prot);
	} else {
		printf ("\n");
	}

	start = get_timer (0);
	last  = start;
	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
		if (info->protect[sect] == 0) {	/* not protected */
			vu_long *addr = (vu_long *)(info->start[sect]);
			unsigned long status;

			/* Disable interrupts which might cause a timeout here */
			flag = disable_interrupts();

			*addr = 0x00600060;	/* clear lock bit setup */
			*addr = 0x00D000D0;	/* clear lock bit confirm */

			udelay (1000);
			/* This takes awfully long - up to 50 ms and more */
			while (((status = *addr) & 0x00800080) != 0x00800080) {
				if ((now=get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
					printf ("Timeout\n");
					*addr = 0x00FF00FF; /* reset to read mode */
					return 1;
				}

				/* show that we're waiting */
				if ((now - last) > 1000) {	/* every second */
					putc ('.');
					last = now;
				}
				udelay (1000);	/* to trigger the watchdog */
			}

			*addr = 0x00500050;	/* clear status register */
			*addr = 0x00200020;	/* erase setup */
			*addr = 0x00D000D0;	/* erase confirm */

			/* re-enable interrupts if necessary */
			if (flag)
				enable_interrupts();

			/* wait at least 80us - let's wait 1 ms */
			udelay (1000);

			while (((status = *addr) & 0x00800080) != 0x00800080) {
				if ((now=get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
					printf ("Timeout\n");
					*addr = 0x00B000B0; /* suspend erase	  */
					*addr = 0x00FF00FF; /* reset to read mode */
					return 1;
				}

				/* show that we're waiting */
				if ((now - last) > 1000) {	/* every second */
					putc ('.');
					last = now;
				}
				udelay (1000);	/* to trigger the watchdog */
			}

			*addr = 0x00FF00FF;	/* reset to read mode */
		}
	}
	printf (" done\n");
	return 0;
}

/*-----------------------------------------------------------------------
 * Copy memory to flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 * 4 - Flash not identified
 */

#define	FLASH_WIDTH	4	/* flash bus width in bytes */

int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
	ulong cp, wp, data;
	int i, l, rc;

	if (info->flash_id == FLASH_UNKNOWN) {
		return 4;
	}

	wp = (addr & ~(FLASH_WIDTH-1));	/* get lower FLASH_WIDTH aligned address */

	/*
	 * handle unaligned start bytes
	 */
	if ((l = addr - wp) != 0) {
		data = 0;
		for (i=0, cp=wp; i<l; ++i, ++cp) {
			data = (data << 8) | (*(uchar *)cp);
		}
		for (; i<FLASH_WIDTH && cnt>0; ++i) {
			data = (data << 8) | *src++;
			--cnt;
			++cp;
		}
		for (; cnt==0 && i<FLASH_WIDTH; ++i, ++cp) {
			data = (data << 8) | (*(uchar *)cp);
		}

		if ((rc = write_data(info, wp, data)) != 0) {
			return (rc);
		}
		wp += FLASH_WIDTH;
	}

	/*
	 * handle FLASH_WIDTH aligned part
	 */
#ifdef CFG_FLASH_USE_BUFFER_WRITE
	while(cnt >= FLASH_WIDTH) {
		i = CFG_FLASH_BUFFER_SIZE > cnt ?
		    (cnt & ~(FLASH_WIDTH - 1)) : CFG_FLASH_BUFFER_SIZE;
		if((rc = write_data_buf(info, wp, src,i)) != 0)
			return rc;
		wp += i;
		src += i;
		cnt -=i;
	}
#else
	while (cnt >= FLASH_WIDTH) {
		data = 0;
		for (i=0; i<FLASH_WIDTH; ++i) {
			data = (data << 8) | *src++;
		}
		if ((rc = write_data(info, wp, data)) != 0) {
			return (rc);
		}
		wp  += FLASH_WIDTH;
		cnt -= FLASH_WIDTH;
	}
#endif /* CFG_FLASH_USE_BUFFER_WRITE */

	if (cnt == 0) {
		return (0);
	}

	/*
	 * handle unaligned tail bytes
	 */
	data = 0;
	for (i=0, cp=wp; i<FLASH_WIDTH && cnt>0; ++i, ++cp) {
		data = (data << 8) | *src++;
		--cnt;
	}
	for (; i<FLASH_WIDTH; ++i, ++cp) {
		data = (data << 8) | (*(uchar *)cp);
	}

	return (write_data(info, wp, data));
}

/*-----------------------------------------------------------------------
 * Check flash status, returns:
 * 0 - OK
 * 1 - timeout
 */
static int flash_status_check(vu_long *addr, ulong tout, char * prompt)
{
	ulong status;
	ulong start;

	/* Wait for command completion */
	start = get_timer (0);
	while(((status = *addr) & 0x00800080) != 0x00800080) {
		if (get_timer(start) > tout) {
			printf("Flash %s timeout at address %p\n", prompt, addr);
			*addr = 0x00FF00FF;	/* restore read mode */
			return (1);
		}
	}
	return 0;
}

/*-----------------------------------------------------------------------
 * Write a word to Flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */
static int write_data (flash_info_t *info, ulong dest, ulong data)
{
	vu_long *addr = (vu_long *)dest;
	int flag;

	/* Check if Flash is (sufficiently) erased */
	if ((*addr & data) != data) {
		return (2);
	}
	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

	*addr = 0x00400040;		/* write setup */
	*addr = data;

	/* re-enable interrupts if necessary */
	if (flag)
		enable_interrupts();

	if (flash_status_check(addr, CFG_FLASH_WRITE_TOUT, "write") != 0) {
		return (1);
	}

	*addr = 0x00FF00FF;	/* restore read mode */

	return (0);
}

#ifdef CFG_FLASH_USE_BUFFER_WRITE
/*-----------------------------------------------------------------------
 * Write a buffer to Flash, returns:
 * 0 - OK
 * 1 - write timeout
 */
static int write_data_buf(flash_info_t * info, ulong dest, uchar * cp, int len)
{
	vu_long *addr = (vu_long *)dest;
	int sector;
	int cnt;
	int retcode;
	vu_long * src = (vu_long *)cp;
	vu_long * dst = (vu_long *)dest;

	/* find sector */
	for(sector = info->sector_count - 1; sector >= 0; sector--) {
		if(dest >= info->start[sector])
			break;
	}

	*addr = 0x00500050;		/* clear status */
	*addr = 0x00e800e8;		/* write buffer */

	if((retcode = flash_status_check(addr, CFG_FLASH_BUFFER_WRITE_TOUT,
					 "write to buffer")) == 0) {
		cnt = len / FLASH_WIDTH;
		*addr = (cnt-1) | ((cnt-1) << 16);
		while(cnt-- > 0) {
			*dst++ = *src++;
		}
		*addr = 0x00d000d0;		/* write buffer confirm */
		retcode = flash_status_check(addr, CFG_FLASH_BUFFER_WRITE_TOUT,
						 "buffer write");
	}
	*addr = 0x00FF00FF;	/* restore read mode */
	*addr = 0x00500050;	/* clear status */
	return retcode;
}
#endif /* CFG_USE_FLASH_BUFFER_WRITE */

/*-----------------------------------------------------------------------
 */