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

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

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

3 files changed, 22 insertions, 27 deletions

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index ce1cbdcd355a..d88c7f7fc619 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;
 }
 
 /**
@@ -757,9 +744,9 @@ 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;
@@ -773,7 +760,7 @@ 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);
@@ -1508,7 +1495,7 @@ 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;
@@ -1963,7 +1950,10 @@ static int onenand_probe(struct mtd_info *mtd)
         density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT;
         this->chipsize = (16 << density) << 20;
         /* Set density mask. it is used for DDP */
-        this->density_mask = (1 << (density + 6));
+        if (ONENAND_IS_DDP(this))
+                this->density_mask = (1 << (density + 6));
+        else
+                this->density_mask = 0;
 
         /* OneNAND page size & block size */
         /* The data buffer size is equal to page size */
diff --git a/include/linux/mtd/onenand.h b/include/linux/mtd/onenand.h
index f775a7af3890..a99b2944d26b 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 e31c8f5d4271..5b46cb52d214 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)