From: Kyungmin Park <kyungmin.park@samsung.com>
Date: Fri, 12 May 2006 14:02:31 +0000 (+0300)
Subject: OneNAND: handle byte access on BufferRAM
X-Git-Tag: v2.6.18-rc1~1105^2~127
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9c01f87db183403a4f603fe5180c57b82b54b4a1;p=linux-2.6

OneNAND: handle byte access on BufferRAM

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index d6c13f7ae5..1439c9fa1d 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -373,6 +373,17 @@ static int onenand_read_bufferram(struct mtd_info *mtd, int area,
 
 	bufferram += onenand_bufferram_offset(mtd, area);
 
+	if (ONENAND_CHECK_BYTE_ACCESS(count)) {
+		unsigned short word;
+
+		/* Align with word(16-bit) size */
+		count--;
+
+		/* Read word and save byte */
+		word = this->read_word(bufferram + offset + count);
+		buffer[count] = (word & 0xff);
+	}
+
 	memcpy(buffer, bufferram + offset, count);
 
 	return 0;
@@ -400,6 +411,17 @@ static int onenand_sync_read_bufferram(struct mtd_info *mtd, int area,
 
 	this->mmcontrol(mtd, ONENAND_SYS_CFG1_SYNC_READ);
 
+	if (ONENAND_CHECK_BYTE_ACCESS(count)) {
+		unsigned short word;
+
+		/* Align with word(16-bit) size */
+		count--;
+
+		/* Read word and save byte */
+		word = this->read_word(bufferram + offset + count);
+		buffer[count] = (word & 0xff);
+	}
+
 	memcpy(buffer, bufferram + offset, count);
 
 	this->mmcontrol(mtd, 0);
@@ -427,6 +449,22 @@ static int onenand_write_bufferram(struct mtd_info *mtd, int area,
 
 	bufferram += onenand_bufferram_offset(mtd, area);
 
+	if (ONENAND_CHECK_BYTE_ACCESS(count)) {
+		unsigned short word;
+		int byte_offset;
+
+		/* Align with word(16-bit) size */
+		count--;
+
+		/* Calculate byte access offset */
+		byte_offset = offset + count;
+
+		/* Read word and save byte */
+		word = this->read_word(bufferram + byte_offset);
+		word = (word & ~0xff) | buffer[count];
+		this->write_word(word, bufferram + byte_offset);
+	}
+
 	memcpy(bufferram + offset, buffer, count);
 
 	return 0;
diff --git a/include/linux/mtd/onenand.h b/include/linux/mtd/onenand.h
index 7419b5fab1..22322c8a77 100644
--- a/include/linux/mtd/onenand.h
+++ b/include/linux/mtd/onenand.h
@@ -130,6 +130,9 @@ struct onenand_chip {
 #define ONENAND_SET_SYS_CFG1(v, this)					\
 	(this->write_word(v, this->base + ONENAND_REG_SYS_CFG1))
 
+/* Check byte access in OneNAND */
+#define ONENAND_CHECK_BYTE_ACCESS(addr)		(addr & 0x1)
+
 /*
  * Options bits
  */