OneNAND: Select correct chip's bufferRAM for DDP

From: Adrian Hunter <[email protected]>
Date: Thu, 8 Feb 2007 10:28:08 +0200
Subject: [MTD] OneNAND: Select correct chip's bufferRAM for DDP

OneNAND double-density package (DDP) has two chips, each with their own bufferRAM. The driver will skip loading data from the NAND core if the data can be found in a bufferRAM, however in that case, the correct chip's bufferRAM must be selected before reading from bufferRAM.

---
drivers/mtd/onenand/onenand_base.c | 24 ++++++++++++++++--------

1 files changed, 16 insertions(+), 8 deletions(-)

index cf66c93..162a373 100644
@@ -577,7 +577,7 @@ static int onenand_write_bufferram(struc

static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)

{
	struct onenand_chip *this = mtd->priv;
-	int blockpage;
+	int blockpage, found = 0;
	unsigned int i;

	blockpage = (int) (addr >> this->page_shift);
@@ -585,16 +585,24 @@ static int onenand_check_bufferram(struc
	/* Is there valid data? */
	i = ONENAND_CURRENT_BUFFERRAM(this);
	if (this->bufferram[i].blockpage == blockpage)

- return 1;
+ found = 1;
+ else {
+ /* Check another BufferRAM */
+ i = ONENAND_NEXT_BUFFERRAM(this);
+ if (this->bufferram[i].blockpage == blockpage) {
+ ONENAND_SET_NEXT_BUFFERRAM(this);
+ found = 1;
+ }
+ }

- /* Check another BufferRAM */
- i = ONENAND_NEXT_BUFFERRAM(this);
- if (this->bufferram[i].blockpage == blockpage) {
- ONENAND_SET_NEXT_BUFFERRAM(this);
- return 1;
+ if (found && ONENAND_IS_DDP(this)) {
+ /* Select DataRAM for DDP */
+ int block = (int) (addr >> this->erase_shift);
+ int value = onenand_bufferram_address(this, block);

+		this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
	}

- return 0;
+ return found;
}

/**

1.4.3

Hi,

Ah, I missed the OneNAND DDP test.
I'll push it

Thank you,
Kyungmin Park