flash.c

AT91RM9200的完整启动代码：包括loader, boot及U-boot三部分均已编译通过！欢迎下载使用！

		info->flash_id = FLASH_UNKNOWN;
		return (0);			/* => no or unknown flash */

	}

	/* set up sector start address table */
	flash_get_offsets (base, info);

	/* 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 */
#ifdef CONFIG_MVS_16BIT_FLASH
		addr = (vu_short *)(info->start[i]);
#else
		addr = (vu_long *)(info->start[i]);
#endif
		info->protect[i] = addr[2] & 1;
	}

	/*
	 * Prevent writes to uninitialized FLASH.
	 */
	if (info->flash_id != FLASH_UNKNOWN) {
#ifdef CONFIG_MVS_16BIT_FLASH
		addr = (vu_short *)info->start[0];
#else
		addr = (vu_long *)info->start[0];
#endif
		*addr = RESET_BANK_DATA;	/* reset bank */
	}

	return (info->size);
}


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

#define ERASE_ADDR1 0x0555
#define ERASE_ADDR2 0x02AA
#define ERASE_ADDR3 ERASE_ADDR1
#define ERASE_ADDR4 ERASE_ADDR1
#define ERASE_ADDR5 ERASE_ADDR2

#define ERASE_DATA1 (0x00AA00AA & FLASH_DATA_MASK)
#define ERASE_DATA2 (0x00550055 & FLASH_DATA_MASK)
#define ERASE_DATA3 (0x00800080 & FLASH_DATA_MASK)
#define ERASE_DATA4 ERASE_DATA1
#define ERASE_DATA5 ERASE_DATA2

#define ERASE_SECTOR_DATA (0x00300030 & FLASH_DATA_MASK)
#define ERASE_CHIP_DATA (0x00100010 & FLASH_DATA_MASK)
#define ERASE_CONFIRM_DATA (0x00800080 & FLASH_DATA_MASK)

int	flash_erase (flash_info_t *info, int s_first, int s_last)
{
#ifdef CONFIG_MVS_16BIT_FLASH
	vu_short *addr = (vu_short *)(info->start[0]);
#else
	vu_long *addr = (vu_long *)(info->start[0]);
#endif
	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 1;
	}

	if ((info->flash_id == FLASH_UNKNOWN) ||
	    (info->flash_id > FLASH_AMD_COMP)) {
		printf ("Can't erase unknown flash type %08lx - aborted\n",
			info->flash_id);
		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");
	}

	l_sect = -1;

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

	addr[ERASE_ADDR1] = ERASE_DATA1;
	addr[ERASE_ADDR2] = ERASE_DATA2;
	addr[ERASE_ADDR3] = ERASE_DATA3;
	addr[ERASE_ADDR4] = ERASE_DATA4;
	addr[ERASE_ADDR5] = ERASE_DATA5;

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
		if (info->protect[sect] == 0) {	/* not protected */
#ifdef CONFIG_MVS_16BIT_FLASH
			addr = (vu_short *)(info->start[sect]);
#else
			addr = (vu_long *)(info->start[sect]);
#endif
			addr[0] = ERASE_SECTOR_DATA;
			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;
#ifdef CONFIG_MVS_16BIT_FLASH
	addr = (vu_short *)(info->start[l_sect]);
#else
	addr = (vu_long *)(info->start[l_sect]);
#endif
	while ((addr[0] & ERASE_CONFIRM_DATA) != ERASE_CONFIRM_DATA) {
		if ((now = get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
			printf ("Timeout\n");
			return 1;
		}
		/* show that we're waiting */
		if ((now - last) > 1000) {	/* every second */
			putc ('.');
			last = now;
		}
	}

DONE:
	/* reset to read mode */
#ifdef CONFIG_MVS_16BIT_FLASH
	addr = (vu_short *)info->start[0];
#else
	addr = (vu_long *)info->start[0];
#endif
	addr[0] = RESET_BANK_DATA;	/* reset bank */

	printf (" done\n");
	return 0;
}


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

int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
#define BUFF_INC 4
	ulong cp, wp, data;
	int i, l, rc;

	mvdebug (("+write_buff %p ==> 0x%08lx, count = 0x%08lx\n", src, addr, cnt));

	wp = (addr & ~3);	/* get lower word aligned address */
	/*
	 * handle unaligned start bytes
	 */
	if ((l = addr - wp) != 0) {
		mvdebug ((" handle unaligned start bytes (cnt = 0x%08%lx)\n", cnt));
		data = 0;
		for (i=0, cp=wp; i<l; ++i, ++cp) {
			data = (data << 8) | (*(uchar *)cp);
		}
		for (; i<BUFF_INC && cnt>0; ++i) {
			data = (data << 8) | *src++;
			--cnt;
			++cp;
		}
		for (; cnt==0 && i<BUFF_INC; ++i, ++cp) {
			data = (data << 8) | (*(uchar *)cp);
		}

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

	/*
	 * handle (half)word aligned part
	 */
	mvdebug ((" handle word aligned part (cnt = 0x%08%lx)\n", cnt));
	while (cnt >= BUFF_INC) {
		data = 0;
		for (i=0; i<BUFF_INC; ++i) {
			data = (data << 8) | *src++;
		}
		if ((rc = write_word(info, wp, data)) != 0) {
			return (rc);
		}
		wp  += BUFF_INC;
		cnt -= BUFF_INC;
	}

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

	/*
	 * handle unaligned tail bytes
	 */
	mvdebug ((" handle unaligned tail bytes (cnt = 0x%08%lx)\n", cnt));
	data = 0;
	for (i=0, cp=wp; i<BUFF_INC && cnt>0; ++i, ++cp) {
		data = (data << 8) | *src++;
		--cnt;
	}
	for (; i<BUFF_INC; ++i, ++cp) {
		data = (data << 8) | (*(uchar *)cp);
	}

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

#define WRITE_ADDR1 0x0555
#define WRITE_ADDR2 0x02AA
#define WRITE_ADDR3 WRITE_ADDR1

#define WRITE_DATA1 (0x00AA00AA & FLASH_DATA_MASK)
#define WRITE_DATA2 (0x00550055 & FLASH_DATA_MASK)
#define WRITE_DATA3 (0x00A000A0 & FLASH_DATA_MASK)

#define WRITE_CONFIRM_DATA ERASE_CONFIRM_DATA

#ifndef CONFIG_MVS_16BIT_FLASH
/*-----------------------------------------------------------------------
 * 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;

	mvdebug (("+write_word (to 0x%08lx)\n", dest));
	/* 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[WRITE_ADDR1] = WRITE_DATA1;
	addr[WRITE_ADDR2] = WRITE_DATA2;
	addr[WRITE_ADDR3] = WRITE_DATA3;

	*((vu_long *)dest) = data;

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

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

 	mvdebug (("-write_word\n"));
	return (0);
}
#else /* CONFIG_MVS_16BIT_FLASH */
/*-----------------------------------------------------------------------
 * Write a halfword to Flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */
static int write_halfword (flash_info_t *info, ulong dest, ushort data)
{
	vu_short *addr = (vu_short *)(info->start[0]);
	ulong start;
	int flag;

	mvdebug (("+write_halfword (to 0x%08lx)\n", dest));
	/* Check if Flash is (sufficiently) erased */
	if ((*((vu_short *)dest) & data) != data) {
		return (2);
	}
	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

	addr[WRITE_ADDR1] = WRITE_DATA1;
	addr[WRITE_ADDR2] = WRITE_DATA2;
	addr[WRITE_ADDR3] = WRITE_DATA3;

	*((vu_short *)dest) = data;

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

	/* data polling for D7 */
	start = get_timer (0);
	addr = (vu_short *)dest;
	while ((*addr & WRITE_CONFIRM_DATA) != (data & WRITE_CONFIRM_DATA)) {
		if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
			return (1);
		}
	}
 	mvdebug (("-write_halfword\n"));
	return (0);
}


/*-----------------------------------------------------------------------
 * 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)
{
	int result = 0;

	if (write_halfword (info, dest, (data & ~FLASH_DATA_MASK) >> 16) == 0)
	{
		dest += 2;
		data = data & FLASH_DATA_MASK;
		result = write_halfword (info, dest, data);
	}
	return result;
}
#endif
/*-----------------------------------------------------------------------
 */