[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>
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 2ea07f57..2da6bb2 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -710,7 +710,7 @@
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 @@
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 @@
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);