From 0fc2ccea4c8fa779053cb6f8984f6da399a81182 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 9 Jan 2007 17:55:21 +0200 Subject: [MTD] OneNAND: Handle DDP chip boundary during read-while-load The read-while-load method of reading from OneNAND needs to allow for the change of bufferRAM address at the boundary between the two chips in a double density (DDP) device. Signed-off-by: Adrian Hunter Signed-off-by: Kyungmin Park --- drivers/mtd/onenand/onenand_base.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'drivers/mtd/onenand') diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c index 2ea07f5723d..2da6bb26353 100644 --- a/drivers/mtd/onenand/onenand_base.c +++ b/drivers/mtd/onenand/onenand_base.c @@ -710,7 +710,7 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len, struct mtd_ecc_stats stats; int read = 0, column; int thislen; - int ret = 0; + int ret = 0, boundary = 0; DEBUG(MTD_DEBUG_LEVEL3, "onenand_read: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len); @@ -749,6 +749,17 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len, from += thislen; if (read + thislen < len) { this->command(mtd, ONENAND_CMD_READ, from, mtd->writesize); + /* + * Chip boundary handling in DDP + * 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); + boundary = 1; + } else + boundary = 0; ONENAND_SET_PREV_BUFFERRAM(this); } /* While load is going, read from last bufferRAM */ @@ -758,6 +769,8 @@ static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len, if (read == len) break; /* Set up for next read from bufferRAM */ + if (unlikely(boundary)) + this->write_word(0x8000, this->base + ONENAND_REG_START_ADDRESS2); ONENAND_SET_NEXT_BUFFERRAM(this); buf += thislen; thislen = min_t(int, mtd->writesize, len - read); -- cgit v1.2.3-70-g09d2