/* libflash.c: Flash memory programming library.

	Copyright 1998-2003 by Donald Becker.
	This software may be used and distributed according to the terms of
	the GNU General Public License (GPL), incorporated herein by reference.
	If you use this code in your own program or make any modification the
	programs I release you must output the full notice required by the GPL.
	Contact the author for use under other terms.

	The author may be reached as becker@scyld.com, or C/O
	 Scyld Computing Corporation
	 914 Bay Ridge Road, Suite 220
	 Annapolis MD 21403

	Support and updates available at
	http://www.scyld.com/diag/index.html

	References:
	http://www.atmel.com/atmel/products/prod9.htm
	http://www.ssti.com/products/products.html
*/
static const char version_msg[] =
"libflash.c:v2.06a 7/4/2003 Copyright Donald Becker, becker@scyld.com";

/* External interface
      flash_show(), flash_dump() and flash_program()
	ADDR_IOADDR is a 32-bit I/O space register that sets the Flash ROM address.
		It is always accessed as  outl(val, ADDR_IOADDR)
	DATA_IOADDR is an 8-bit I/O register from which the Flash ROM data is read.
		It is always accessed with inb or outb  e.g.  outb(val, DATA_IOADDR)
	FILENAME is a filename where the Flash image is stored.
	The caller does any register setup required.
*/

/*  External interface to this library.  Functions and variables: */
/* Show the Flash contents on stdout. */
extern int flash_show   (long addr_ioaddr, long data_ioaddr);
/* Read or write the Flash, writing/reading FILENAME. */
extern int flash_program(long addr_ioaddr, long data_ioaddr, char *filename);
extern int flash_dump   (long addr_ioaddr, long data_ioaddr, char *filename);

extern int verbose;				/* Set to non-zero for info. */
extern int debug;				/* Currently unused. */

/* Callback hooks for accessing single words of the flash chip.
   Chips that have a I/O space 32 bit address register and do an 8 bit
   read/write register will not need this. */
int (*flash_in_hook)(long addr, int offset) = 0;
void (*flash_out_hook)(long addr, int offset, int val) = 0;

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>
#if defined(__linux__)  &&  __GNU_LIBRARY__ == 1
#include <asm/io.h>			/* Newer libraries use <sys/io.h> instead. */
#else
#include <sys/io.h>
#endif

/* Size of read() for byte oriented parts.
   Page oriented parts read in units of the chip page size.
*/
#define RD_PAGE_SIZE 4096

enum flash_flags { ERASE_FIRST=1, };
struct flash_id_table {
	unsigned char vendor_id, device_id;
	enum flash_flags flags;
	int mem_size, page_size;
	char *part_name;
} static flash_id[] = {
	{ 0x12, 0x34, 0,   8*1024,   1, "Unknown Flash EEPROM", },
	/* Sector program, no erase needed parts. */
	{ 0xBF, 0x07, 0, 128*1024, 128, "Silicon Storage Technology SST29EE010", },
	{ 0xBF, 0x08, 0, 128*1024, 128, "Silicon Storage Technology SST29LE010", },
	{ 0x1F, 0xDC, 0,  32*1024,  64, "Atmel AT29C256", },
	{ 0x1F, 0xBC, 0,  32*1024,  64, "Atmel AT29LV256", },
	{ 0x1F, 0x5D, 0,  64*1024, 128, "Atmel AT29C512", },
	{ 0x1F, 0x3D, 0,  64*1024, 128, "Atmel AT29LV512", },
	{ 0x1F, 0xD5, 0, 128*1024, 128, "Atmel AT29C010A", },
	{ 0x1F, 0x35, 0, 128*1024, 128, "Atmel AT29LV010A", },
	{ 0x1F, 0xDA, 0, 256*1024, 256, "Atmel AT29C020", },
	{ 0x1F, 0xBA, 0, 256*1024, 256, "Atmel AT29LV020", },
	{ 0x1F, 0x5B, 0, 512*1024, 512, "Atmel AT29C040", },
	{ 0x1F, 0x3B, 0, 512*1024, 512, "Atmel AT29LV040", },
	{ 0x1F, 0xA4, 0, 512*1024, 256, "Atmel AT29C040A", },
	{ 0x1F, 0xC4, 0, 512*1024, 256, "Atmel AT29LV040A", },
	/* Bulk-erase, byte-program parts. */
	{ 0x1F, 0x03, ERASE_FIRST, 64*1024,   1, "Atmel AT49BV512", },
	/* AMD parts that require 90/01 read method. */
	{ 0x01, 0x6D, 0, 128*1024, 8*1024, "AMD Am29LV001BB", },
	{ 0x01, 0xED, 0, 128*1024, 8*1024, "AMD Am29LV001BT", },
	{ 0x01, 0x40, 0, 256*1024, 8*1024, "AMD Am29LV002BT", },
	{ 0x01, 0xC2, 0, 256*1024, 8*1024, "AMD Am29LV002BB", },
	{ 0x01, 0x34, 0, 256*1024, 8*1024, "AMD Am29F002BB", },
	{ 0x01, 0xB0, 0, 256*1024, 8*1024, "AMD Am29F002BT", },
	{ 0x01, 0x7B, 0, 512*1024, 8*1024, "AMD Am29F004BB", },
	{ 0x01, 0x77, 0, 512*1024, 8*1024, "AMD Am29F004BT", },
	{ 0x01, 0xB5, 0, 512*1024, 8*1024, "AMD Am29LV004BT", },
	{ 0x01, 0xB6, 0, 512*1024, 8*1024, "AMD Am29LV004BB", },
	{ 0x01, 0x37, 0, 1024*1024, 8*1024, "AMD Am29LV008BB", },
	{ 0x01, 0x3E, 0, 1024*1024, 8*1024, "AMD Am29LV008BT", },
	{ 0x01, 0x4C, 0, 2048*1024, 8*1024, "AMD Am29LV116DB", },
	{ 0x01, 0xC7, 0, 2048*1024, 8*1024, "AMD Am29LV116DT", },
	{ 0x01, 0x6E, 0, 128*1024, 128, "AMD Am29LV010B", },
	{ 0x01, 0x4F, 0, 512*1024, 128, "AMD Am29LV040B", },
	{ 0x01, 0x03, 0, 0, 0, "AMD Am29BL162C", },
	{ 0x01, 0x38, 0, 0, 0, "AMD Am29LV081B", },
	{ 0x01, 0x20, ERASE_FIRST, 128*1024, 1, "AMD Am29F010B", },
	{ 0x01, 0xA4, ERASE_FIRST, 512*1024, 1, "AMD Am29F040B", },
	{ 0x01, 0xD5, ERASE_FIRST, 1024*1024, 1, "AMD Am29F080B", },
	{ 0x01, 0xAD, 0, 0, 0, "AMD Am29F016D", },
	{ 0x01, 0x3D, 0, 0, 0, "AMD Am29F017D", },
	{ 0x01, 0x41, 0, 0, 0, "AMD Am29F032B", },
	{ 0x01, 0x45, 0, 0, 0, "AMD Am29PL160C", },
	{ 0x01, 0x81, 0, 0, 0, "AMD Am29BL802C", },
	{ 0x01, 0x51, 0, 0, 0, "AMD Am29F200BT", },
	{ 0x01, 0x57, 0, 0, 0, "AMD Am29F200BB", },
	{ 0x01, 0x23, 0, 0, 0, "AMD Am29F400BT", },
	{ 0x01, 0xAB, 0, 0, 0, "AMD Am29F400BB", },
	{ 0x01, 0xD6, 0, 0, 0, "AMD Am29F800BT", },
	{ 0x01, 0x58, 0, 0, 0, "AMD Am29F800BB", },
	{ 0x01, 0xD2, 0, 0, 0, "AMD Am29F160DT", },
	{ 0x01, 0xD8, 0, 0, 0, "AMD Am29F160DB", },
	{ 0x01, 0x93, 0, 0, 0, "AMD Am29LV065D", },
	{ 0x01, 0x95, 0, 0, 0, "AMD Am29DS163DT", },
	{ 0x01, 0x96, 0, 0, 0, "AMD Am29DS163DB", },
	{ 0x01, 0xA3, 0, 0, 0, "AMD Am29LV033C", },
	{ 0x01, 0xC8, 0, 0, 0, "AMD Am29LV017D", },
	{ 0x01, 0xD7, 0, 0, 0, "AMD Am29LV640D", },
	{ 0xDA, 0xC1, 0, 128*1024, 128, "Winbond W29EE011", },
	{ 0,},
};

struct extended_flash_id_table {
	unsigned char vendor_id, device_id[3];
	enum flash_flags flags;
	int mem_size, page_size;
	char *part_name;
}  full_flash_id[] = {
	/* AMD part IDs from AN-AMD25536 rev. A+1 Nov. 8, 2001 */
	{ 0x01, {0x7E, 0x02, 0x00,}, 0, 0, 0, "AMD Am29BDS643D", },
	{ 0x01, {0x7E, 0x02, 0x01,}, 0, 0, 0, "AMD Am29BDS640D", },
	{ 0x01, {0x7E, 0x03, 0x00,}, 0, 0, 0, "AMD Am29BDS320DB", },
	{ 0x01, {0x7E, 0x03, 0x01,}, 0, 0, 0, "AMD Am29BDS320DT", },
	{ 0x01, {0x7E, 0x06, 0x00,}, 0, 0, 0, "AMD Am29PD322DB", },
	{ 0x01, {0x7E, 0x06, 0x01,}, 0, 0, 0, "AMD Am29PD322DT", },
	{ 0x01, {0x7E, 0x0C, 0x00,}, 0, 0, 0, "AMD Am29PD640GL", },
	{ 0x01, {0x7E, 0x0C, 0x01,}, 0, 0, 0, "AMD Am29PD640MH", },
	{ 0x01, {0x7E, 0x0E, 0x00,}, 0, 0, 0, "AMD Am29PD640GB", },
	{ 0x01, {0x7E, 0x0E, 0x01,}, 0, 0, 0, "AMD Am29PD640GT", },
	{ 0x01, {0x7E, 0x10, 0x00,}, 0, 0, 0, "AMD AM29LV640MB", },
	{ 0x01, {0x7E, 0x10, 0x01,}, 0, 0, 0, "AMD AM29LV640MT", },
	{ 0x01, {0x7E, 0x11, 0x00,}, 0, 0, 0, "AMD AM29LV641MB", },
	{ 0x01, {0x7E, 0x11, 0x01,}, 0, 0, 0, "AMD AM29LV641MT", },
	{ 0x01, {0x7E, 0x12, 0x00,}, 0, 16*1024, 0, "AMD AM29LV128M", },
	{ 0x01, {0x7E, 0x12, 0x01,}, 0, 32*1024, 0, "AMD AM29LV256M", },
	{ 0x01, {0x7E, 0x13, 0x00,}, 0, 0, 0, "AMD AM29LV065M", },
	{ 0x01, {0x7E, 0x13, 0x01,}, 0, 0, 0, "AMD AM29LV641M", },
	{ 0,},
};

/* A few limits based on the table above. */
#define MAX_PAGE_SIZE 1024
#define MAX_PART_SIZE 512*1024

/* Index of internal functions. */
static int get_part_id(long addr_ioaddr, long data_ioaddr);
void sst_flash_clear(long addr_ioaddr, long data_ioaddr);
static void do_cmd(long addr_ioaddr, long data_ioaddr, int cmd);

static inline void flash_out(long addr_ioaddr, long data_ioaddr, int offset,
							 int val)
{
	if (flash_out_hook) {
		(*flash_out_hook)(addr_ioaddr, offset, val);
		return;
	}
	outl(offset, addr_ioaddr);
	outb(val, data_ioaddr);
}
static inline int flash_in(long addr_ioaddr, long data_ioaddr, int offset)
{
	if (flash_in_hook)
		return (*flash_in_hook)(addr_ioaddr, offset);
	outl(offset, addr_ioaddr);
	return inb(data_ioaddr) & 0xff;
}

static int get_part_id(long addr_ioaddr, long data_ioaddr)
{
	int id0, id1;
	int old[2];
	int i;

	old[0] = flash_in(addr_ioaddr, data_ioaddr, 0);
	old[1] = flash_in(addr_ioaddr, data_ioaddr, 1);

#if 0
	/* Check for an immediate-write Flash by checking for programming delay.
	   However this check is falsely triggered / unreliable. */
	flash_out(addr_ioaddr, data_ioaddr, 0, old[0]);
	if (flash_in(addr_ioaddr, data_ioaddr, 0) != old[0]) {
		if (verbose)
			printf("No BIOS ROM ID, immediate-write flash (%2.2x).\n",
				   flash_in(addr_ioaddr, data_ioaddr, 0));
		for (i = 10000; i > 0; i--)
			if (flash_in(addr_ioaddr, data_ioaddr, 0) == old[0])
				break;
		return -1;
	}
#endif

	do_cmd(addr_ioaddr, data_ioaddr, 0x90);
	/* usleep(10);*/
	id0 = flash_in(addr_ioaddr, data_ioaddr, 0);
	id1 = flash_in(addr_ioaddr, data_ioaddr, 1);
#if 0  /* Test code only. */
	for (i = 0; i < 1000; i++) {
		printf("Flash ID is %x %x\r", id0, id1);
		id0 = flash_in(addr_ioaddr, data_ioaddr, 0);
		id1 = flash_in(addr_ioaddr, data_ioaddr, 1);
	}
#endif
	if (old[0] == id0  &&  old[1] == id1) {
		/* Some SST parts only respond to the two-part ID command. */
		printf("Hmmm, no response to the ID command, trying again with "
			   "'80/60'..\n");
		do_cmd(addr_ioaddr, data_ioaddr, 0x80);
		do_cmd(addr_ioaddr, data_ioaddr, 0x60);
		usleep(10);
		id0 = flash_in(addr_ioaddr, data_ioaddr, 0);
		id1 = flash_in(addr_ioaddr, data_ioaddr, 1);
	}
	if (old[0] == id0  &&  old[1] == id1) {
		printf("That did not work either, trying with '90/01'...\n");
		do_cmd(addr_ioaddr, data_ioaddr, 0x90);
		flash_out(addr_ioaddr, data_ioaddr, 0x000, 01);
		id0 = flash_in(addr_ioaddr, data_ioaddr, 0);
		id1 = flash_in(addr_ioaddr, data_ioaddr, 1);
	}
	if (old[0] == id0  &&  old[1] == id1) {
		printf("ACKKK, this may not be a programmable Flash part!\n");
	}

	if (verbose > 1)
		printf(" BIOS ROM ID %2.2X %2.2X, looking up vendor...\n", id0, id1);

	/* Exit ID mode. */
	do_cmd(addr_ioaddr, data_ioaddr, 0xF0);
	usleep(10);

	for (i = 0; flash_id[i].vendor_id; i++)
		if (flash_id[i].vendor_id == id0  &&  flash_id[i].device_id == id1)
			break;
	if (flash_id[i].vendor_id == 0) {
		printf("Unknown BIOS ROM ID %2.2X %2.2X.\n", id0, id1);
		return -1;
	}
	if (verbose)
		printf("BIOS ROM ID %2.2X %2.2X, vendor %s:\n", id0, id1,
			   flash_id[i].part_name ? flash_id[i].part_name : "");
	return i;
}

int flash_show(long addr_ioaddr, long data_ioaddr)
{
	unsigned char old_inval[16], inval[16];
	int addr, did_dots = 0;
	int i, part_id, mem_size;

	part_id = get_part_id(addr_ioaddr, data_ioaddr);
	mem_size = (part_id < 0) ? 64*1024 : flash_id[part_id].mem_size;

	for (addr = 0; addr < mem_size; addr+=16) {
		for (i = 0; i < 16; i++) {
			inval[i] = flash_in(addr_ioaddr, data_ioaddr, addr + i);
		}
		if (addr == 0 || memcmp(inval, old_inval, sizeof(old_inval))) {
			printf("0x%3.3x: ", addr);
			for (i = 0; i < 16; i++)
				printf("%2.2x ", inval[i]);
			for (i = 0; i < 16; i++)
				printf("%c", isalnum(inval[i]) ? inval[i] : '.');
			printf("\n");
			memcpy(old_inval, inval, sizeof(old_inval));
			did_dots = 0;
		} else if (! did_dots) {
			did_dots = 1;
			printf("...\n");
		}
	}
	printf("\nBIOS ROM dump done.\n");
	return 0;
}

int flash_dump(long addr_ioaddr, long data_ioaddr, char *filename)
{
	char wbuf[4096];
	int fd, i, offset, cnt;
	int	part_id = get_part_id(addr_ioaddr, data_ioaddr);
	int mem_size = (part_id < 0) ? 8*1024 : flash_id[part_id].mem_size;

	printf("Saving the boot flash ROM into file '%s'...", filename);
	fflush(stdout);
	if ((fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0444)) < 0) {
		perror("flash_dump");
		return -1;
	}
	for (offset = 0; offset < mem_size; offset += cnt) {
		int blk_size = sizeof(wbuf) < 128*1024 - offset
			? sizeof(wbuf) : 128*1024 - offset;
		for (i = 0; i < blk_size; i++) {
			wbuf[i] = flash_in(addr_ioaddr, data_ioaddr, offset + i);
		}
		cnt = write(fd, wbuf, i);
		if (cnt < 0) {
			perror("save_flash");
			return -1;
		}
	}
	printf("done.\n");
	return 0;
}

/* Bulk erase the flash ROM. */
void sst_flash_clear(long addr_ioaddr, long data_ioaddr)
{
	int j;

	do_cmd(addr_ioaddr, data_ioaddr, 0x80);
	do_cmd(addr_ioaddr, data_ioaddr, 0x10);

	printf("Chiperase...");
	/*
	 * Poll for the erase to complete,
	 * wait until status bits stop toggling.
	 */
	for (j = 0; j < 2000000; j++)
		if (flash_in(addr_ioaddr, data_ioaddr, 0) ==
		    flash_in(addr_ioaddr, data_ioaddr, 0)) {
			printf(" OK\n");
			return;
		}

	printf(" Timed out\n");
}

int flash_program(long addr_ioaddr, long data_ioaddr, char *filename)
{
	int fd, i;
	int offset = 0, eofflag = 0;
	int	part_id = get_part_id(addr_ioaddr, data_ioaddr);
	int page_size = part_id > 0 ? flash_id[part_id].page_size : 128;
	int	flags = flash_id[part_id].flags;

	if (verbose)
		fprintf(stderr, "%s", version_msg);
	if (part_id < 0) {
		fprintf(stderr, "  This is an unknown flash chip, which cannot be "
				"programmed.\n");
		return -1;
	}

	if ((fd = open(filename, O_RDONLY)) < 0) {
		perror("flash_program");
		return -1;
	}

	if (page_size == 1) {		/* This is a byte-by-byte part. */
		unsigned char rbuf[RD_PAGE_SIZE];

		if (flags & ERASE_FIRST)
			sst_flash_clear(addr_ioaddr, data_ioaddr);

		do {
			int rcnt = read(fd, rbuf, sizeof(rbuf));

			if (rcnt < 0) {
				perror("flash_load");
				fprintf(stderr, "read(%d,%d,%d)\n",
						fd, offset, (int)sizeof(rbuf));
				return -1;
			} else if (rcnt == 0) {
				eofflag++;
				break;
			}
			for (i = 0; i < rcnt; i++) {
				int j;
				do_cmd(addr_ioaddr, data_ioaddr, 0xA0);
				flash_out(addr_ioaddr, data_ioaddr, offset++, rbuf[i]);
				/* Poll for the write to complete, look for stable read. */
				for (j = 0; j < 100000; j++)
					if (flash_in(addr_ioaddr, data_ioaddr, 0) ==
						flash_in(addr_ioaddr, data_ioaddr, 0))
						break;
				if (verbose > 2)
					printf("Write %2.2x to %d completed after %d ticks.\n",
						   rbuf[i], offset, j);
			}

		} while (! eofflag  &&  offset < MAX_PART_SIZE);
		printf("\rFinished programming %d bytes into the flash ROM.\n",
			   offset);
		return 0;
	}
			
	do {
		int rcnt, cnt = 0;
		unsigned char rbuf[MAX_PAGE_SIZE];

		/* The flash image should be in a file, and we should never
		   encounter short reads.  But it's a disaster if we do, so we guard
		   against it. */
		do {
			rcnt = read(fd, rbuf + cnt, page_size - cnt);
			if (rcnt < 0) {
				perror("flash_load");
				fprintf(stderr, "read(%d,%p,%d)\n",
						fd, rbuf + cnt, page_size - cnt);
				return -1;
			} else if (rcnt == 0) {
				eofflag++;
				break;
			}
			cnt += rcnt;
		} while (page_size - cnt > 0);

		if (cnt == 0  &&  eofflag)
			break;

		/* At this point rbuf[] is either a full block, or the tail of
		   data to be written.  We cannot allow blocks to span the 128 byte
		   flash pages. */
		do_cmd(addr_ioaddr, data_ioaddr, 0xA0);
		for (i = 0; i < cnt; i++) {
			flash_out(addr_ioaddr, data_ioaddr, offset + i, rbuf[i]);
		}
		if (verbose) {
			printf("\rWriting a block of %d bytes at offset %#x..",
				   cnt, offset);
			if (verbose > 1)
				printf("%2.2x %2.2x %2.2x %2.2x %2.2x .",
					   rbuf[0], rbuf[1], rbuf[2], rbuf[3], rbuf[4]);
			fflush(stdout);
		}
		/* Pause for 200usec. to allow the write to start. */
		usleep(200);
		/* And then poll for the write to complete, look for stable read. */
		for (i = 0; i < 100000; i++)
			if (flash_in(addr_ioaddr, data_ioaddr, 0) ==
 				flash_in(addr_ioaddr, data_ioaddr, 0))
				break;
		if (verbose > 2)
			printf("Write completed after %d ticks.\n", i);
		/* Verify the write. */
		for (i = 0; i < cnt; i++) {
			unsigned char val = flash_in(addr_ioaddr, data_ioaddr, offset + i);
			if (val != rbuf[i]) {
				fprintf(stderr, "\n Flash ROM write failed at offset %d, "
						"0x%2.2x vs. 0x%2.2x.\n", offset + i, val, rbuf[i]);
				return -1;
			}
		}
		offset += cnt;
	} while (! eofflag  &&  offset < MAX_PART_SIZE);

	printf("\rFinished programming %d bytes into the flash ROM.\n",
		   offset);
	return 0;
}

static void do_cmd(long addr_ioaddr, long data_ioaddr, int cmd)
{
	flash_out(addr_ioaddr, data_ioaddr, 0x5555, 0xAA);
	flash_out(addr_ioaddr, data_ioaddr, 0x2AAA, 0x55);
	flash_out(addr_ioaddr, data_ioaddr, 0x5555, cmd);
	/* Alternate command is simply
	   flash_out(addr_ioaddr, data_ioaddr, 0, cmd); */
}

/*
 * Local variables:
 *  compile-command: "cc -O -Wall -c libflash.c"
 *  c-indent-level: 4
 *  c-basic-offset: 4
 *  tab-width: 4
 * End:
 */