sst39sf020 support

Corresponding to coreboot v1 svn r524.
diff --git a/sst39sf020.c b/sst39sf020.c
new file mode 100644
index 0000000..3c310a7
--- /dev/null
+++ b/sst39sf020.c
@@ -0,0 +1,163 @@
+/*
+ * sst39sf020.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_39sf020 (volatile char * bios)
+{
+	/* ask compiler not to optimize this */
+	volatile unsigned char tmp;
+
+	tmp = *(volatile unsigned char *) (bios + 0x1823);
+	tmp = *(volatile unsigned char *) (bios + 0x1820);
+	tmp = *(volatile unsigned char *) (bios + 0x1822);
+	tmp = *(volatile unsigned char *) (bios + 0x0418);
+	tmp = *(volatile unsigned char *) (bios + 0x041B);
+	tmp = *(volatile unsigned char *) (bios + 0x0419);
+	tmp = *(volatile unsigned char *) (bios + 0x040A);
+}
+
+static __inline__ void unprotect_39sf020 (volatile char * bios)
+{
+	/* ask compiler not to optimize this */
+	volatile unsigned char tmp;
+
+	tmp = *(volatile unsigned char *) (bios + 0x1823);
+	tmp = *(volatile unsigned char *) (bios + 0x1820);
+	tmp = *(volatile unsigned char *) (bios + 0x1822);
+	tmp = *(volatile unsigned char *) (bios + 0x0418);
+	tmp = *(volatile unsigned char *) (bios + 0x041B);
+	tmp = *(volatile unsigned char *) (bios + 0x0419);
+	tmp = *(volatile unsigned char *) (bios + 0x041A);
+}
+
+static __inline__ erase_sector_39sf020 (volatile 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_39sf020(volatile char * bios, unsigned char * src,
+				       volatile unsigned char * dst, unsigned int page_size)
+{
+	int i;
+	volatile char *Temp;
+
+	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;
+		}
+            Temp =   (bios + 0x5555); 
+            *Temp = 0xAA;                   
+            Temp =  bios + 0x2AAA; 
+            *Temp = 0x55; 
+            Temp =  bios + 0x5555; 
+            *Temp = 0xA0;                   
+		*dst++ = *src++;
+		toggle_ready_jedec(bios);
+	}
+}
+
+int probe_39sf020 (struct flashchip * flash)
+{
+        volatile char * bios = flash->virt_addr;
+        unsigned char  id1, id2;
+
+        *(volatile char *) (bios + 0x5555) = 0xAA;
+        myusec_delay(10);
+        *(volatile char *) (bios + 0x2AAA) = 0x55;
+        myusec_delay(10);
+        *(volatile char *) (bios + 0x5555) = 0x90;
+
+        myusec_delay(10);
+
+        id1 = *(volatile unsigned char *) bios;
+        id2 = *(volatile unsigned char *) (bios + 0x01);
+
+        *(volatile char *) (bios + 0x5555) = 0xAA;
+        *(volatile char *) (bios + 0x2AAA) = 0x55;
+        *(volatile char *) (bios + 0x5555) = 0xF0;
+
+        myusec_delay(10);
+
+        printf(__FUNCTION__ "id1 %d, id2 %d\n", id1, id2);
+        if (id1 == flash->manufacture_id && id2 == flash->model_id)
+                return 1;
+
+        return 0;
+}
+
+int erase_39sf020 (struct flashchip * flash)
+{
+	volatile char * bios = flash->virt_addr;
+
+	unprotect_39sf020 (bios);
+	*bios = CHIP_ERASE;
+	*bios = CHIP_ERASE;
+	protect_39sf020 (bios);
+
+	myusec_delay(10);
+	toggle_ready_jedec(bios);
+}
+
+int write_39sf020 (struct flashchip * flash, char * buf)
+{
+	int i;
+	int total_size = flash->total_size * 1024, page_size = flash->page_size;
+	volatile char * bios = flash->virt_addr;
+
+//	unprotect_39sf020 (bios);
+
+	printf ("Programming Page: ");
+	for (i = 0; i < total_size/page_size; i++) {
+		/* erase the page before programming */
+		//erase_sector_39sf020(bios, i * page_size);
+
+		/* write to the sector */
+		printf ("%04d at address: 0x%08x", i, i * page_size);
+		write_sector_39sf020(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_39sf020 (bios);
+}