From 8d5e29095ebc8d69554b7b6f4b9cef8a3d111053 Mon Sep 17 00:00:00 2001
From: Bas Wijnen <wijnen@debian.org>
Date: Tue, 12 Oct 2010 19:29:58 +0200
Subject: [PATCH] allow using 2GB nand and ignore 'valid'-bits

---
 mips/nand.hhp | 62 +++++++++++++++------------------------------------
 1 file changed, 18 insertions(+), 44 deletions(-)

diff --git a/mips/nand.hhp b/mips/nand.hhp
index dc05740..7d68f7b 100644
--- a/mips/nand.hhp
+++ b/mips/nand.hhp
@@ -134,7 +134,7 @@ static bool read (unsigned a, char *buffer):
 	//  33: 9-byte ecc of 4th 512 bytes
 	//  42: unused
 	//  64: end of space
-	unsigned col = (1 << page_bits) + 2
+	unsigned col = (1 << page_bits) + 6 + 9 * (column >> 9)
 	cmd (CMD_READ0)
 	addr (col)
 	addr (col >> 8)
@@ -142,21 +142,6 @@ static bool read (unsigned a, char *buffer):
 	addr (row >> 8)
 	addr (row >> 16)
 	cmd (CMD_READSTART)
-	bool valid = false
-	for unsigned t = 0; t < 3; ++t:
-		if rdata () == 0:
-			valid = true
-			break
-	if !valid:
-		//debug ("invalid page for nand read: %x\n", a)
-		for unsigned i = 0; i < 1 << (9 - 2); ++i:
-			((unsigned *)buffer)[i] = ~0
-		return false
-	col = (1 << page_bits) + 6 + 9 * (column >> 9)
-	cmd (CMD_RNDOUT)
-	addr (col)
-	addr (col >> 8)
-	cmd (CMD_RNDOUTSTART)
 	//debug ("parity data:")
 	for unsigned t = 0; t < 9; ++t:
 		error[t] = rdata ()
@@ -192,17 +177,18 @@ static bool read (unsigned a, char *buffer):
 		data ^= mask << offset
 		buffer[byte] = data
 		buffer[byte + 1] = data >> 8
+	#if 0
 	for unsigned i = 0; i < 0x10; ++i:
 		if (buffer[i] & 0xff) < 0x10:
-			//debug (" 0")
+			debug (" 0")
 		else:
-			//debug (" ")
-		//debug ("%x", buffer[i] & 0xff)
-	//debug ("\n")
+			debug (" ")
+		debug ("%x", buffer[i] & 0xff)
+	debug ("\n")
+	#endif
 	return true
 
 static void write (unsigned a, char *buffer):
-	dbgl ()
 	unsigned row = a >> page_bits
 	//debug ("writing: %x/%x\n", a, row)
 	cmd (CMD_SEQIN)
@@ -211,10 +197,8 @@ static void write (unsigned a, char *buffer):
 	addr (row)
 	addr (row >> 8)
 	addr (row >> 16)
-	char ecc[4][12]
-	dbgl ()
-	for unsigned i = 0; i < 0x4; ++i:
-		dbgl ()
+	char ecc[8][12]
+	for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
 		bool all_ff = true
 		EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_ENCODING | EMC_NFECR_ERST
 		//debug ("writing data from %x\n", (unsigned)buffer + i * 0x200)
@@ -225,19 +209,15 @@ static void write (unsigned a, char *buffer):
 		if !all_ff:
 			while !(EMC_NFINTS & EMC_NFINTS_ENCF):
 				DELAY ()
-			dbgl ()
 			for unsigned t = 0; t < 9; ++t:
 				ecc[i][t] = ((volatile char *)&EMC_NFPAR (0))[t]
-			dbgl ()
 			//debug ("parity for %x:", i * 0x200 + a)
 			//for unsigned t = 0; t < 9; ++t:
 				//debug (" %x", ecc[i][t] & 0xff)
 			//kdebug ("\n")
 		else:
-			dbgl ()
 			for unsigned t = 0; t < 9; ++t:
 				ecc[i][t] = 0xff
-	dbgl ()
 	// Spare space (starts at 1 << page_bits)
 	//  0: unused
 	//  2: detect valid data (at least 1 byte == 0 means valid)
@@ -250,14 +230,12 @@ static void write (unsigned a, char *buffer):
 	//  64: end of space
 	for unsigned i = 0; i < 6; ++i:
 		wdata (0)
-	for unsigned i = 0; i < 4; ++i:
+	for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
 		for unsigned j = 0; j < 9; ++j:
 			wdata (ecc[i][j])
-	dbgl ()
 	cmd (CMD_PAGEPROG)
 	// Wait at least 100 ns.
 	DELAY ()
-	dbgl ()
 	cmd (CMD_READ0)
 	addr (0)
 	addr (0)
@@ -265,9 +243,7 @@ static void write (unsigned a, char *buffer):
 	addr (row >> 8)
 	addr (row >> 16)
 	cmd (CMD_READSTART)
-	dbgl ()
-	for unsigned i = 0; i < 4; ++i:
-		dbgl ()
+	for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
 		EMC_NFINTS = 0
 		EMC_NFECR = EMC_NFECR_ECCE | EMC_NFECR_RS | EMC_NFECR_RS_DECODING | EMC_NFECR_ERST
 		for unsigned t = 0; t < 0x200; ++t:
@@ -292,26 +268,24 @@ static void write (unsigned a, char *buffer):
 			unsigned offset= bit & 7
 			unsigned byte = bit / 8
 			debug ("error detected by parity: %x on %x+%d\n", mask, byte, offset)
-	dbgl ()
 	for unsigned i = 0; i < 6; ++i:
 		if rdata () != 0:
 			debug ("extra data not 0 at byte %d\n", i)
-	dbgl ()
-	for unsigned i = 0; i < 4; ++i:
+	for unsigned i = 0; i < 1 << (page_bits - 9); ++i:
 		for unsigned j = 0; j < 9; ++j:
 			unsigned r = rdata () & 0xff
 			if r != (ecc[i][j] & 0xff):
 				debug ("ecc doesn't match: %x != %x\n", r, ecc[i][j] & 0xff)
-	dbgl ()
 	//debug ("nand program %x:", a)
+	#if 0
 	for unsigned i = 0; i < 0x10; ++i:
 		if (buffer[i] & 0xff) < 0x10:
-			//debug (" 0")
+			debug (" 0")
 		else:
-			//debug (" ")
-		//debug ("%x", buffer[i] & 0xff)
-	dbgl ()
-	//debug ("\n")
+			debug (" ")
+		debug ("%x", buffer[i] & 0xff)
+	debug ("\n")
+	#endif
 
 static void erase (unsigned a):
 	unsigned row = a >> page_bits