[PATCH] OneNAND: Reduce OneNAND Double Density Package (DDP) operations

[Kyungmin Park <kyungmin.park@samsung.com>]

[PATCH] OneNAND: Reduce OneNAND DDP operations

- DDP code clean-up
- Reduce block & bufferram operations

If there's no objection, I will commit it.

Thank you,
Kyungmin Park

--

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index d0f3118..dfeccfc 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -94,16 +94,9 @@ static void onenand_writew(unsigned short value, void __iomem *addr)
  */
 static int onenand_block_address(struct onenand_chip *this, int block)
 {
-	if (this->device_id & ONENAND_DEVICE_IS_DDP) {
-		/* Device Flash Core select, NAND Flash Block Address */
-		int dfs = 0;
-
-		if (block & this->density_mask)
-			dfs = 1;
-
-		return (dfs << ONENAND_DDP_SHIFT) |
-			(block & (this->density_mask - 1));
-	}
+	/* Device Flash Core select, NAND Flash Block Address */
+	if (block & this->density_mask)
+		return ONENAND_DDP_CHIP1 | (block ^ this->density_mask);
 
 	return block;
 }
@@ -118,17 +111,11 @@ static int onenand_block_address(struct onenand_chip *this, int block)
  */
 static int onenand_bufferram_address(struct onenand_chip *this, int block)
 {
-	if (this->device_id & ONENAND_DEVICE_IS_DDP) {
-		/* Device BufferRAM Select */
-		int dbs = 0;
-
-		if (block & this->density_mask)
-			dbs = 1;
+	/* Device BufferRAM Select */
+	if (block & this->density_mask)
+		return ONENAND_DDP_CHIP1;
 
-		return (dbs << ONENAND_DDP_SHIFT);
-	}
-
-	return 0;
+	return ONENAND_DDP_CHIP0;
 }
 
 /**
@@ -754,9 +741,9 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
  			 * Now we issued chip 1 read and pointed chip 1
  			 * bufferam so we have to point chip 0 bufferam.
  			 */
- 			if (this->device_id & ONENAND_DEVICE_IS_DDP &&
- 					unlikely(from == (this->chipsize >> 1))) {
- 				this->write_word(0, this->base + ONENAND_REG_START_ADDRESS2);
+ 			if (ONENAND_IS_DDP(this) &&
+			    unlikely(from == (this->chipsize >> 1))) {
+ 				this->write_word(ONENAND_DDP_CHIP0, this->base + ONENAND_REG_START_ADDRESS2);
  				boundary = 1;
  			} else
  				boundary = 0;
@@ -770,7 +757,7 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
  			break;
  		/* Set up for next read from bufferRAM */
  		if (unlikely(boundary))
- 			this->write_word(0x8000, this->base + ONENAND_REG_START_ADDRESS2);
+ 			this->write_word(ONENAND_DDP_CHIP1, this->base + ONENAND_REG_START_ADDRESS2);
  		ONENAND_SET_NEXT_BUFFERRAM(this);
  		buf += thislen;
  		thislen = min_t(int, mtd->writesize, len - read);
@@ -1505,7 +1492,7 @@ static int onenand_unlock_all(struct mtd_info *mtd)
 			continue;
 
 		/* Workaround for all block unlock in DDP */
-		if (this->device_id & ONENAND_DEVICE_IS_DDP) {
+		if (ONENAND_IS_DDP(this)) {
 			/* 1st block on another chip */
 			loff_t ofs = this->chipsize >> 1;
 			size_t len = mtd->erasesize;
diff --git a/include/linux/mtd/onenand.h b/include/linux/mtd/onenand.h
index f775a7a..a99b294 100644
--- a/include/linux/mtd/onenand.h
+++ b/include/linux/mtd/onenand.h
@@ -150,6 +150,9 @@ struct onenand_chip {
 #define ONENAND_SET_SYS_CFG1(v, this)					\
 	(this->write_word(v, this->base + ONENAND_REG_SYS_CFG1))
 
+#define ONENAND_IS_DDP(this)						\
+	(this->device_id & ONENAND_DEVICE_IS_DDP)
+
 /* Check byte access in OneNAND */
 #define ONENAND_CHECK_BYTE_ACCESS(addr)		(addr & 0x1)
 
diff --git a/include/linux/mtd/onenand_regs.h b/include/linux/mtd/onenand_regs.h
index e31c8f5..5b46cb5 100644
--- a/include/linux/mtd/onenand_regs.h
+++ b/include/linux/mtd/onenand_regs.h
@@ -80,9 +80,11 @@
 #define ONENAND_VERSION_PROCESS_SHIFT	(8)
 
 /*
- * Start Address 1 F100h (R/W)
+ * Start Address 1 F100h (R/W) & Start Address 2 F101h (R/W)
  */
 #define ONENAND_DDP_SHIFT		(15)
+#define ONENAND_DDP_CHIP0		(0)
+#define ONENAND_DDP_CHIP1		(1 << ONENAND_DDP_SHIFT)
 
 /*
  * Start Address 8 F107h (R/W)