From 5e5f75e559f605974afd3767bc650a1cc0ed6f1f Mon Sep 17 00:00:00 2001
From: "Ronald G. Minnich" <rminnich@gmail.com>
Date: Tue, 29 Jan 2002 18:21:41 +0000
Subject: Trying to make this general purpose user-land flash burner

Corresponding to coreboot v1 svn r489.
---
 sst28sf040.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 159 insertions(+)
 create mode 100644 sst28sf040.c

(limited to 'sst28sf040.c')

diff --git a/sst28sf040.c b/sst28sf040.c
new file mode 100644
index 0000000..e0e5ea3
--- /dev/null
+++ b/sst28sf040.c
@@ -0,0 +1,159 @@
+/*
+ * sst28sf040.c: driver for SST28SF040C flash models.
+ *
+ *
+ * Copyright 2000 Silicon Integrated System Corporation
+ *
+ *	This program is free software; you can redistribute it and/or modify
+ *	it under the terms of the GNU General Public License as published by
+ *	the Free Software Foundation; either version 2 of the License, or
+ *	(at your option) any later version.
+ *
+ *	This program is distributed in the hope that it will be useful,
+ *	but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *	GNU General Public License for more details.
+ *
+ *	You should have received a copy of the GNU General Public License
+ *	along with this program; if not, write to the Free Software
+ *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * Reference:
+ *	4 MEgabit (512K x 8) SuperFlash EEPROM, SST28SF040 data sheet
+ *
+ * $Id$
+ */
+
+#include "flash.h"
+#include "jedec.h"
+
+#define AUTO_PG_ERASE1		0x20
+#define AUTO_PG_ERASE2		0xD0
+#define AUTO_PGRM			0x10
+#define CHIP_ERASE		0x30
+#define RESET			0xFF
+#define READ_ID			0x90
+
+static __inline__ void protect_28sf040 (char * bios)
+{
+	/* ask compiler not to optimize this */
+	volatile unsigned char tmp;
+
+	tmp = *(unsigned char *) (bios + 0x1823);
+	tmp = *(unsigned char *) (bios + 0x1820);
+	tmp = *(unsigned char *) (bios + 0x1822);
+	tmp = *(unsigned char *) (bios + 0x0418);
+	tmp = *(unsigned char *) (bios + 0x041B);
+	tmp = *(unsigned char *) (bios + 0x0419);
+	tmp = *(unsigned char *) (bios + 0x040A);
+}
+
+static __inline__ void unprotect_28sf040 (char * bios)
+{
+	/* ask compiler not to optimize this */
+	volatile unsigned char tmp;
+
+	tmp = *(unsigned char *) (bios + 0x1823);
+	tmp = *(unsigned char *) (bios + 0x1820);
+	tmp = *(unsigned char *) (bios + 0x1822);
+	tmp = *(unsigned char *) (bios + 0x0418);
+	tmp = *(unsigned char *) (bios + 0x041B);
+	tmp = *(unsigned char *) (bios + 0x0419);
+	tmp = *(unsigned char *) (bios + 0x041A);
+}
+
+static __inline__ erase_sector_28sf040 (char * bios, unsigned long address)
+{
+	*bios = AUTO_PG_ERASE1;
+	*(bios + address) = AUTO_PG_ERASE2;
+
+	/* wait for Toggle bit ready         */
+	toggle_ready_jedec(bios);
+}
+
+static __inline__ write_sector_28sf040(char * bios, unsigned char * src,
+				       unsigned char * dst, unsigned int page_size)
+{
+	int i;
+
+	for (i = 0; i < page_size; i++) {
+		/* transfer data from source to destination */
+		if (*src == 0xFF) {
+			dst++, src++;
+			/* If the data is 0xFF, don't program it */
+			continue;
+		}
+		/*issue AUTO PROGRAM command */
+		*dst =  AUTO_PGRM;
+		*dst++ = *src++;
+
+		/* wait for Toggle bit ready */
+		toggle_ready_jedec(bios);
+	}
+}
+
+int probe_28sf040 (struct flashchip * flash)
+{
+	char * bios = flash->virt_addr;
+	unsigned char  id1, id2, tmp;
+
+	/* save the value at the beginning of the Flash */
+	tmp = *bios;
+
+	*bios = RESET;
+	usleep(10);
+
+	*bios = READ_ID;
+	usleep(10);
+	id1 = *(unsigned char *) bios;
+	usleep(10);
+	id2 = *(unsigned char *) (bios + 0x01);
+
+	*bios = RESET;
+	usleep(10);
+
+	if (id1 == flash->manufacture_id && id2 == flash->model_id)
+		return 1;
+
+	/* if there is no SST28SF040, restore the original value */
+	*bios = tmp;
+	return 0;
+}
+
+int erase_28sf040 (struct flashchip * flash)
+{
+	char * bios = flash->virt_addr;
+
+	unprotect_28sf040 (bios);
+	*bios = CHIP_ERASE;
+	*bios = CHIP_ERASE;
+	protect_28sf040 (bios);
+
+	usleep(10);
+	toggle_ready_jedec(bios);
+}
+
+int write_28sf040 (struct flashchip * flash, char * buf)
+{
+	int i;
+	int total_size = flash->total_size * 1024, page_size = flash->page_size;
+	char * bios = flash->virt_addr;
+
+	unprotect_28sf040 (bios);
+
+	printf ("Programming Page: ");
+	for (i = 0; i < total_size/page_size; i++) {
+		/* erase the page before programming */
+		erase_sector_28sf040(bios, i * page_size);
+
+		/* write to the sector */
+		printf ("%04d at address: 0x%08x", i, i * page_size);
+		write_sector_28sf040(bios, buf + i * page_size, bios + i * page_size,
+				     page_size);
+		printf ("\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b");
+	}
+	printf("\n");
+
+	protect_28sf040 (bios);
+}
-- 
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