flash.c

Linux2.4.27在AT91RM9200下的U-BOOT代码。可以在Redhat9等版本下使用。适合ARM学习者使用。

			printf ("- missing\n");
		} else {
			printf ("- no sectors to erase\n");
		}
		return 1;
	}

	if ((info->flash_id & FLASH_VENDMASK) != (INTEL_MANUFACT & FLASH_VENDMASK)) {
		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");
	}

	start = get_timer (0);

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
		char tmp;

		if (info->protect[sect] == 0) {	/* not protected */
			addr = (vu_short *)(info->start[sect]);

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

			/* Single Block Erase Command */
			*addr = 0x0020;
			/* Confirm */
			*addr = 0x00D0;
			/* Resume Command, as per errata update */
			*addr = 0x00D0;

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

			*addr = 0x70; /*Read status register command*/
			tmp = (short)*addr & 0x00FF; /* Read the status */
			while (!(tmp & INTEL_FLASH_STATUS_WSMS)) {
				if ((now=get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
					*addr = 0x0050; /* Reset the status register */
					*addr = 0xffff;
					printf ("Timeout\n");
					return 1;
				}
				/* show that we're waiting */
				if ((now - start) > 1000) {	/* every second */
					putc ('.');
				}
				udelay(100000); /* 100 ms */
				*addr = 0x0070; /*Read status register command*/
				tmp = (short)*addr & 0x00FF; /* Read status */
				start = get_timer(0);
			}
			if( tmp & INTEL_FLASH_STATUS_ES )
				flash_decode_status_bits(tmp);

			*addr = 0x0050; /* Reset the status register */
			*addr = 0xffff; /* Reset to read mode */
		}
	}


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

void flash_unprotect (flash_info_t *info)
{
	/*We can only unprotect the whole flash at once*/
	/*Therefore we must prevent the _flash_real_protect()*/
	/*from re-protecting sectors, that ware protected before */
	/*we called flash_real_protect();*/

	int i;

	for(i = 0; i < info->sector_count; i++)
		info->protect[i] = 0;

#ifdef CFG_FLASH_PROTECTION
		_flash_real_protect(info, 0, 0);
#endif
}

/*-----------------------------------------------------------------------
 * 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)
{
	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
 */
int write_word (flash_info_t *info, ulong dest, ulong da)
{
	vu_short *addr = (vu_short *)dest;
	ulong start;
	char csr;
	int flag;
	ushort * d = (ushort*)&da;
	int i;

	/* Check if Flash is (sufficiently) erased */
	if (((*addr & d[0]) != d[0]) || ((*(addr+1) & d[1]) != d[1])) {
		return (2);
	}
	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

	for(i = 0; i < 2; i++)
	{
		/* Write Command */
		*addr = 0x0010;

		/* Write Data */
		*addr = d[i];

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

		/* data polling for D7 */
		start = get_timer (0);
		flag  = 0;
		*addr = 0x0070; /*Read statusregister command */
		while (((csr = *addr) & INTEL_FLASH_STATUS_WSMS)!=INTEL_FLASH_STATUS_WSMS) {
			if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
				flag = 1;
				break;
			}
			*addr = 0x0070; /*Read statusregister command */
		}
		if (csr & INTEL_FLASH_STATUS_PSS) {
			printf ("CSR indicates write error (%0x) at %08lx\n",
					csr, (ulong)addr);
			flag = 1;
		}

		/* Clear Status Registers Command */
		*addr = 0x0050;
		/* Reset to read array mode */
		*addr = 0xffff;
		addr++;
	}

	return (flag);
}

int flash_real_protect(flash_info_t *info, long offset, int prot)
{
	int i, idx;

	for(idx = 0; idx < info->sector_count; idx++)
		if(info->start[idx] == offset)
			break;

	if(idx==info->sector_count)
		return -1;

	if(prot == 0) {
		/* Unprotect one sector, which means unprotect all flash
		 * and reprotect the other protected sectors.
		 */
		_flash_real_protect(info, 0, 0); /* Unprotects the whole flash*/
		info->protect[idx] = 0;

		for(i = 0; i < info->sector_count; i++)
			if(info->protect[i])
				_flash_real_protect(info, i, 1);
		}
	else {
		/* We can protect individual sectors */
		_flash_real_protect(info, idx, 1);
	}

	for( i = 0; i < info->sector_count; i++)
		info->protect[i] = flash_get_protect_status(info, i);

	return 0;
}

int _flash_real_protect(flash_info_t *info, long idx, int prot)
{
	vu_short *addr;
	int flag;
	ushort cmd;
	ushort tmp;
	ulong now, start;

	if ((info->flash_id & FLASH_VENDMASK) != (INTEL_MANUFACT & FLASH_VENDMASK)) {
		printf ("Can't change protection for unknown flash type %08lx - aborted\n",
			info->flash_id);
		return -1;
	}

	if(prot == 0) {
		/*Unlock the sector*/
		cmd = 0x00D0;
	}
	else {
		/*Lock the sector*/
		cmd = 0x0001;
	}

	addr = (vu_short *)(info->start[idx]);

	/* If chip is busy, wait for it */
	start = get_timer(0);
	*addr = 0x0070; /*Read status register command*/
	tmp = ((ushort)(*addr))&0x00ff; /*Read the status*/
	while(!(tmp & INTEL_FLASH_STATUS_WSMS)) {
		/*Write State Machine Busy*/
		/*Wait untill done or timeout.*/
		if ((now=get_timer(start)) > CFG_FLASH_WRITE_TOUT) {
			*addr = 0x0050; /* Reset the status register */
			*addr = 0xffff; /* Reset the chip */
			printf ("TTimeout\n");
			return 1;
		}
		*addr = 0x0070;
		tmp = ((ushort)(*addr))&0x00ff; /*Read the status*/
		start = get_timer(0);
	}

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

	/* Unlock block*/
	*addr = 0x0060;

	*addr = cmd;

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

	start = get_timer(0);
	*addr = 0x0070; /*Read status register command*/
	tmp = ((ushort)(*addr)) & 0x00FF; /* Read the status */
	while (!(tmp & INTEL_FLASH_STATUS_WSMS)) {
		/* Write State Machine Busy */
		if ((now=get_timer(start)) > CFG_FLASH_WRITE_TOUT) {
			*addr = 0x0050; /* Reset the status register */
			*addr = 0xffff;
			printf ("Timeout\n");
			return 1;
		}
		/* show that we're waiting */
		if ((now - start) > 1000) {	/* every second */
			putc ('.');
		}
		udelay(100000); /* 100 ms */
		*addr = 0x70; /*Read status register command*/
		tmp = (short)*addr & 0x00FF; /* Read status */
		start = get_timer(0);
	}
	if( tmp & INTEL_FLASH_STATUS_PS )
		flash_decode_status_bits(tmp);

	*addr =0x0050; /*Clear status register*/

	/* reset to read mode */
	*addr = 0xffff;

	return 0;
}