[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 <ext-adrian.hunter@nokia.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
This commit is contained in:
Adrian Hunter 2007-01-09 17:55:21 +02:00 committed by Artem Bityutskiy
parent b3c9f8bfe7
commit 0fc2ccea4c

View File

@ -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);