flash.c

嵌入式ARM的一些源代码

	case AMD_ID_LV160B:
		info->flash_id += FLASH_AM160B;
		info->sector_count = 35;
		info->size = 0x00400000;
		break;				/* => 4 MB		*/
#if 0	/* enable when device IDs are available */
	case AMD_ID_LV320T:
		info->flash_id += FLASH_AM320T;
		info->sector_count = 67;
		info->size = 0x00800000;
		break;				/* => 8 MB		*/

	case AMD_ID_LV320B:
		info->flash_id += FLASH_AM320B;
		info->sector_count = 67;
		info->size = 0x00800000;
		break;				/* => 8 MB		*/
#endif
	default:
		info->flash_id = FLASH_UNKNOWN;
		return (0);			/* => no or unknown flash */

	}

	/* set up sector start adress table */
	if (info->flash_id & FLASH_BTYPE) {
		/* set sector offsets for bottom boot block type	*/
		info->start[0] = base + 0x00000000;
		info->start[1] = base + 0x00008000;
		info->start[2] = base + 0x0000C000;
		info->start[3] = base + 0x00010000;
		for (i = 4; i < info->sector_count; i++) {
			info->start[i] = base + (i * 0x00020000) - 0x00060000;
		}
	} else {
		/* set sector offsets for top boot block type		*/
		i = info->sector_count - 1;
		info->start[i--] = base + info->size - 0x00008000;
		info->start[i--] = base + info->size - 0x0000C000;
		info->start[i--] = base + info->size - 0x00010000;
		for (; i >= 0; i--) {
			info->start[i] = base + i * 0x00020000;
		}
	}

	/* check for protected sectors */
	for (i = 0; i < info->sector_count; i++) {
		/* read sector protection at sector address, (A7 .. A0) = 0x02 */
		/* D0 = 1 if protected */
		addr = (volatile unsigned long *)(info->start[i]);
		info->protect[i] = addr[2] & 1;
	}

	/*
	 * Prevent writes to uninitialized FLASH.
	 */
	if (info->flash_id != FLASH_UNKNOWN) {
		addr = (volatile unsigned long *)info->start[0];

		*addr = 0x00F000F0;	/* reset bank */
	}

	return (info->size);
}


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

void
flash_erase(flash_info_t *info, int s_first, int s_last)
{
	vu_long *addr = (vu_long*)(info->start[0]);
	int flag, prot, sect, l_sect;
	ulong start, now, 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;
	}

	if ((info->flash_id == FLASH_UNKNOWN) ||
	    (info->flash_id > FLASH_AMD_COMP)) {
		printf ("Can't erase unknown flash type - aborted\n");
		return;
	}

	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");
	}

	l_sect = -1;

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

	addr[0x0555] = 0x00AA00AA;
	addr[0x02AA] = 0x00550055;
	addr[0x0555] = 0x00800080;
	addr[0x0555] = 0x00AA00AA;
	addr[0x02AA] = 0x00550055;

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
		if (info->protect[sect] == 0) {	/* not protected */
			addr = (vu_long*)(info->start[sect]);
			addr[0] = 0x00300030;
			l_sect = sect;
		}
	}

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

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

	/*
	 * We wait for the last triggered sector
	 */
	if (l_sect < 0)
		goto DONE;

	start = get_timer (0);
	last  = start;
	addr = (vu_long*)(info->start[l_sect]);
	while ((addr[0] & 0x00800080) != 0x00800080) {
		if ((now = get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
			printf ("Timeout\n");
			return;
		}
		/* show that we're waiting */
		if ((now - last) > 1000) {	/* every second */
			serial_putc ('.');
			last = now;
		}
	}

DONE:
	/* reset to read mode */
	addr = (volatile unsigned long *)info->start[0];
	addr[0] = 0x00F000F0;	/* reset bank */

	printf (" done\n");
}

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

flash_info_t *
addr2info(ulong addr)
{
	flash_info_t *info;
	int i;

	for (i=0, info=&flash_info[0]; i<CFG_MAX_FLASH_BANKS; ++i, ++info) {
		if ((addr >= info->start[0]) &&
		    (addr < (info->start[0] + info->size)) ) {
			return (info);
		}
	}

	return (NULL);
}

/*-----------------------------------------------------------------------
 * Copy memory to flash.
 * Make sure all target addresses are within Flash bounds,
 * and no protected sectors are hit.
 * Returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 * 4 - target range includes protected sectors
 * 8 - target address not in Flash memory
 */
int
flash_write(uchar *src, ulong addr, ulong cnt)
{
	int i;
	ulong         end        = addr + cnt - 1;
	flash_info_t *info_first = addr2info (addr);
	flash_info_t *info_last  = addr2info (end );
	flash_info_t *info;

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

	if (!info_first || !info_last) {
		return (8);
	}

	for (info = info_first; info <= info_last; ++info) {
		ulong b_end = info->start[0] + info->size;	/* bank end addr */
		short s_end = info->sector_count - 1;
		for (i=0; i<info->sector_count; ++i) {
			ulong e_addr = (i == s_end) ? b_end : info->start[i + 1];

			if ((end >= info->start[i]) && (addr < e_addr) &&
			    (info->protect[i] != 0) ) {
				return (4);
			}
		}
	}

	/* finally write data to flash */
	for (info = info_first; info <= info_last && cnt>0; ++info) {
		ulong len;
		
		len = info->start[0] + info->size - addr;
		if (len > cnt)
			len = cnt;
		if ((i = write_buff(info, src, addr, len)) != 0) {
			return (i);
		}
		cnt  -= len;
		addr += len;
		src  += len;
	}
	return (0);
}

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

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

	wp = (addr & ~3);	/* get lower word 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<4 && cnt>0; ++i) {
			data = (data << 8) | *src++;
			--cnt;
			++cp;
		}
		for (; cnt==0 && i<4; ++i, ++cp) {
			data = (data << 8) | (*(uchar *)cp);
		}

		if ((rc = write_word(info, wp, data)) != 0) {
			return (rc);
		}
		wp += 4;
	}

	/*
	 * handle word aligned part
	 */
	while (cnt >= 4) {
		data = 0;
		for (i=0; i<4; ++i) {
			data = (data << 8) | *src++;
		}
		if ((rc = write_word(info, wp, data)) != 0) {
			return (rc);
		}
		wp  += 4;
		cnt -= 4;
	}

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

	/*
	 * handle unaligned tail bytes
	 */
	data = 0;
	for (i=0, cp=wp; i<4 && cnt>0; ++i, ++cp) {
		data = (data << 8) | *src++;
		--cnt;
	}
	for (; i<4; ++i, ++cp) {
		data = (data << 8) | (*(uchar *)cp);
	}
	
	return (write_word(info, wp, data));
}

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

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

	addr[0x0555] = 0x00AA00AA;
	addr[0x02AA] = 0x00550055;
	addr[0x0555] = 0x00A000A0;

	*((vu_long *)dest) = data;

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

	/* data polling for D7 */
	start = get_timer (0);
	while ((*((vu_long *)dest) & 0x00800080) != (data & 0x00800080)) {
		if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
			return (1);
		}
	}
	return (0);
}

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