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。

 */


static u32 _amd_erase_flash(u32 addr, u32 sector)
{
	unsigned elapsed;

	/* Issue erase */
	*(volatile u16*)(addr + 0xaaaa) = 0x00AA;
	*(volatile u16*)(addr + 0x5554) = 0x0055;
	*(volatile u16*)(addr + 0xaaaa) = 0x0080;
	/* And one unlock */
	*(volatile u16*)(addr + 0xaaaa) = 0x00AA;
	*(volatile u16*)(addr + 0x5554) = 0x0055;
	/* Sector erase command comes last */
	*(volatile u16*)(addr + sector) = 0x0030;

	elapsed = *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI); /* dummy read */
	elapsed = 0;
	while (((*(volatile u16*)(addr + sector)) & 0x0080) != 0x0080) {

		elapsed += *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI);
		if (elapsed > ((CFG_FLASH_ERASE_TOUT/CFG_HZ) * 1000)) {
			*(volatile u16*)(addr) = 0x00f0;
			return 1;
		}
	}

	*(volatile u16*)(addr) = 0x00f0;

	return 0;
}

extern int _amd_erase_flash_end;
asm ("_amd_erase_flash_end:\n"
     ".long 0\n");

/* this needs to be inlined, the SWTMRMMILLI register is reset by each read */
#define __udelay(delay) \
{	\
	unsigned micro; \
	unsigned milli=0; \
	\
	micro = *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI); \
	 \
	for (;;) { \
		\
		milli += *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI); \
		micro = *(volatile u16*)(0xfffef000+SC520_SWTMRMICRO); \
		\
		if ((delay) <= (micro + (milli * 1000))) { \
			break; \
		} \
	} \
} while (0)

static u32 _intel_erase_flash(u32 addr, u32 sector)
{
	unsigned elapsed;

	*(volatile u16*)(addr + sector) = 0x0050;   /* clear status register */
	*(volatile u16*)(addr + sector) = 0x0020;   /* erase setup */
	*(volatile u16*)(addr + sector) = 0x00D0;   /* erase confirm */


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

	elapsed = 0;
	while (((*(volatile u16*)(addr + sector)) & 0x0080) != 0x0080) {
		elapsed += *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI);
		if (elapsed > ((CFG_FLASH_ERASE_TOUT/CFG_HZ) * 1000)) {
			*(volatile u16*)(addr + sector) = 0x00B0;  /* suspend erase      */
			*(volatile u16*)(addr + sector) = 0x00FF;  /* reset to read mode */
			return 1;
		}
	}

	*(volatile u16*)(addr + sector) = 0x00FF;  /* reset to read mode */

	return 0;
}


extern int _intel_erase_flash_end;
asm ("_intel_erase_flash_end:\n"
     ".long 0\n");

int flash_erase(flash_info_t *info, int s_first, int s_last)
{
	u32 (*_erase_flash_ptr)(u32 a, u32 so);
	int prot;
	int sect;
	unsigned size;

	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) == (AMD_MANUFACT & FLASH_VENDMASK)) {
		size = (unsigned)&_amd_erase_flash_end - (unsigned)_amd_erase_flash;

		if (size > PROBE_BUFFER_SIZE) {
			printf("_amd_erase_flash() routine too large (%d) %p - %p\n",
			       size, &_amd_erase_flash_end, _amd_erase_flash);
			return 0;
		}

		memcpy(buffer, _amd_erase_flash, size);
		_erase_flash_ptr = (void*)buffer;

	} else if ((info->flash_id & FLASH_VENDMASK) == (INTEL_MANUFACT & FLASH_VENDMASK)) {
		size = (unsigned)&_intel_erase_flash_end - (unsigned)_intel_erase_flash;

		if (size > PROBE_BUFFER_SIZE) {
			printf("_intel_erase_flash() routine too large (%d) %p - %p\n",
			       size, &_intel_erase_flash_end, _intel_erase_flash);
			return 0;
		}

		memcpy(buffer, _intel_erase_flash, size);
		_erase_flash_ptr = (void*)buffer;
	} else {
		printf ("Can't erase unknown flash type - 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 erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {

		if (info->protect[sect] == 0) { /* not protected */
			int res;
			int flag;

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

			res = _erase_flash_ptr(info->start[0], info->start[sect]-info->start[0]);

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


			if (res) {
				printf("Erase timed out, sector %d\n", sect);
				return res;
			}

			putc('.');
		}
	}


	return 0;
}

/*-----------------------------------------------------------------------
 * Write a word to Flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */
static int _amd_write_word(unsigned start, unsigned dest, unsigned data)
{
	volatile u16 *addr2 = (u16*)start;
	volatile u16 *dest2 = (u16*)dest;
	volatile u16 *data2 = (u16*)&data;
	int i;
	unsigned elapsed;

	/* Check if Flash is (sufficiently) erased */
	if ((*((volatile u16*)dest) & (u16)data) != (u16)data) {
		return 2;
	}

	for (i = 0; i < 2; i++) {


		addr2[0x5555] = 0x00AA;
		addr2[0x2aaa] = 0x0055;
		addr2[0x5555] = 0x00A0;

		dest2[i] = (data >> (i*16)) & 0xffff;

		elapsed = *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI); /* dummy read */
		elapsed = 0;

		/* data polling for D7 */
		while ((dest2[i] & 0x0080) != (data2[i] & 0x0080)) {
			elapsed += *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI);
			if (elapsed > ((CFG_FLASH_WRITE_TOUT/CFG_HZ) * 1000)) {
				addr2[i] = 0x00f0;
				return 1;
			}
		}
	}

	addr2[i] = 0x00f0;

	return 0;
}

extern int _amd_write_word_end;
asm ("_amd_write_word_end:\n"
     ".long 0\n");


static int _intel_write_word(unsigned start, unsigned dest, unsigned data)
{
	int i;
	unsigned elapsed;

	/* Check if Flash is (sufficiently) erased */
	if ((*((volatile u16*)dest) & (u16)data) != (u16)data) {
		return 2;
	}

	for (i = 0; i < 2; i++) {

		*(volatile u16*)(dest+2*i) = 0x0040; /* write setup */
		*(volatile u16*)(dest+2*i) = (data >> (i*16)) & 0xffff;

		elapsed = *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI); /* dummy read */
		elapsed = 0;

		/* data polling for D7 */
		while ((*(volatile u16*)dest & 0x0080) != 0x0080) {
			elapsed += *(volatile u16*)(0xfffef000+SC520_SWTMRMILLI);
			if (elapsed > ((CFG_FLASH_WRITE_TOUT/CFG_HZ) * 1000)) {
				*(volatile u16*)dest = 0x00ff;
				return 1;
			}
		}
	}

	*(volatile u16*)dest = 0x00ff;


	return 0;

}

extern int _intel_write_word_end;
asm ("_intel_write_word_end:\n"
     ".long 0\n");


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

int write_buff(flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
	ulong cp, wp, data;
	int i, l, rc;
	int flag;
	u32 (*_write_word_ptr)(unsigned start, unsigned dest, unsigned data);
	unsigned size;

	if ((info->flash_id & FLASH_VENDMASK) == (AMD_MANUFACT & FLASH_VENDMASK)) {
		size = (unsigned)&_amd_write_word_end - (unsigned)_amd_write_word;

		if (size > PROBE_BUFFER_SIZE) {
			printf("_amd_write_word() routine too large (%d) %p - %p\n",
			       size, &_amd_write_word_end, _amd_write_word);
			return 0;
		}

		memcpy(buffer, _amd_write_word, size);
		_write_word_ptr = (void*)buffer;

	} else if ((info->flash_id & FLASH_VENDMASK) == (INTEL_MANUFACT & FLASH_VENDMASK)) {
		size = (unsigned)&_intel_write_word_end - (unsigned)_intel_write_word;

		if (size > PROBE_BUFFER_SIZE) {
			printf("_intel_write_word() routine too large (%d) %p - %p\n",
			       size, &_intel_write_word_end, _intel_write_word);
			return 0;
		}

		memcpy(buffer, _intel_write_word, size);
		_write_word_ptr = (void*)buffer;
	} else {
		printf ("Can't program unknown flash type - aborted\n");
		return 3;
	}


	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 |= (*(uchar *)cp) << (8*i);
		}
		for (; i<4 && cnt>0; ++i) {
			data |= *src++ << (8*i);
			--cnt;
			++cp;
		}
		for (; cnt==0 && i<4; ++i, ++cp) {
			data |= (*(uchar *)cp)  << (8*i);
		}

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

		rc = _write_word_ptr(info->start[0], wp, data);

		/* re-enable interrupts if necessary */
		if (flag) {
			enable_interrupts();
		}
		if (rc != 0) {
			return rc;
		}
		wp += 4;
	}

	/*
	 * handle word aligned part
	 */
	while (cnt >= 4) {
		data = 0;

		for (i=0; i<4; ++i) {
			data |= *src++ << (8*i);
		}

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

		rc = _write_word_ptr(info->start[0], wp, data);

		/* re-enable interrupts if necessary */
		if (flag) {
			enable_interrupts();
		}
		if (rc != 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 |= *src++ << (8*i);
		--cnt;
	}

	for (; i<4; ++i, ++cp) {
		data |= (*(uchar *)cp) << (8*i);
	}

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

	rc = _write_word_ptr(info->start[0], wp, data);

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

	return rc;

}