[Qemu-devel] [PATCH v5 11/24] hw/nand.c: bug fix to BUSY/READY status bit

[Kuo-Jung Su]

From: Kuo-Jung Su <address@hidden>

The BIT6 of Status Register(SR):

SR[6] behaves the same as R/B# pin
    SR[6] = 0 indicates the device is busy;
    SR[6] = 1 means the device is ready

Some NAND flash controller (i.e. ftnandc021) relies on the SR[6]
to determine if the NAND flash erase/program is success or error timeout.

P.S:
The exmaple NAND flash datasheet could be found at following link:
http://www.mxic.com.tw/QuickPlace/hq/PageLibrary4825740B00298A3B.nsf/h_Index/8FEA549237D2F7674825795800104C26/$File/MX30LF1G08AA,%203V,%201Gb,%20v1.1.pdf

Signed-off-by: Kuo-Jung Su <address@hidden>
---
 hw/nand.c |   20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/hw/nand.c b/hw/nand.c
index 4a71265..7f40ebf 100644
--- a/hw/nand.c
+++ b/hw/nand.c
@@ -46,7 +46,7 @@
 # define NAND_IOSTATUS_PLANE1  (1 << 2)
 # define NAND_IOSTATUS_PLANE2  (1 << 3)
 # define NAND_IOSTATUS_PLANE3  (1 << 4)
-# define NAND_IOSTATUS_BUSY    (1 << 6)
+# define NAND_IOSTATUS_READY    (1 << 6)
 # define NAND_IOSTATUS_UNPROTCT        (1 << 7)
 
 # define MAX_PAGE              0x800
@@ -231,6 +231,7 @@ static void nand_reset(DeviceState *dev)
     s->iolen = 0;
     s->offset = 0;
     s->status &= NAND_IOSTATUS_UNPROTCT;
+    s->status |= NAND_IOSTATUS_READY;
 }
 
 static inline void nand_pushio_byte(NANDFlashState *s, uint8_t value)
@@ -647,6 +648,8 @@ static void glue(nand_blk_write_, PAGE_SIZE)(NANDFlashState 
*s)
     if (PAGE(s->addr) >= s->pages)
         return;
 
+    s->status &= ~NAND_IOSTATUS_READY;
+
     if (!s->bdrv) {
         mem_and(s->storage + PAGE_START(s->addr) + (s->addr & PAGE_MASK) +
                         s->offset, s->io, s->iolen);
@@ -656,7 +659,7 @@ static void glue(nand_blk_write_, PAGE_SIZE)(NANDFlashState 
*s)
         soff = SECTOR_OFFSET(s->addr);
         if (bdrv_read(s->bdrv, sector, iobuf, PAGE_SECTORS) < 0) {
             printf("%s: read error in sector %" PRIu64 "\n", __func__, sector);
-            return;
+            goto blkw_out;
         }
 
         mem_and(iobuf + (soff | off), s->io, MIN(s->iolen, PAGE_SIZE - off));
@@ -675,7 +678,7 @@ static void glue(nand_blk_write_, PAGE_SIZE)(NANDFlashState 
*s)
         soff = off & 0x1ff;
         if (bdrv_read(s->bdrv, sector, iobuf, PAGE_SECTORS + 2) < 0) {
             printf("%s: read error in sector %" PRIu64 "\n", __func__, sector);
-            return;
+            goto blkw_out;
         }
 
         mem_and(iobuf + soff, s->io, s->iolen);
@@ -685,6 +688,9 @@ static void glue(nand_blk_write_, PAGE_SIZE)(NANDFlashState 
*s)
         }
     }
     s->offset = 0;
+
+blkw_out:
+    s->status |= NAND_IOSTATUS_READY;
 }
 
 /* Erase a single block */
@@ -697,6 +703,8 @@ static void glue(nand_blk_erase_, PAGE_SIZE)(NANDFlashState 
*s)
     if (PAGE(addr) >= s->pages)
         return;
 
+    s->status &= ~NAND_IOSTATUS_READY;
+
     if (!s->bdrv) {
         memset(s->storage + PAGE_START(addr),
                         0xff, (PAGE_SIZE + OOB_SIZE) << s->erase_shift);
@@ -738,6 +746,8 @@ static void glue(nand_blk_erase_, PAGE_SIZE)(NANDFlashState 
*s)
             printf("%s: write error in sector %" PRIu64 "\n", __func__, page);
         }
     }
+
+    s->status |= NAND_IOSTATUS_READY;
 }
 
 static void glue(nand_blk_load_, PAGE_SIZE)(NANDFlashState *s,
@@ -746,6 +756,8 @@ static void glue(nand_blk_load_, PAGE_SIZE)(NANDFlashState 
*s,
     if (PAGE(addr) >= s->pages)
         return;
 
+    s->status &= ~NAND_IOSTATUS_READY;
+
     if (s->bdrv) {
         if (s->mem_oob) {
             if (bdrv_read(s->bdrv, SECTOR(addr), s->io, PAGE_SECTORS) < 0) {
@@ -769,6 +781,8 @@ static void glue(nand_blk_load_, PAGE_SIZE)(NANDFlashState 
*s,
                         offset, PAGE_SIZE + OOB_SIZE - offset);
         s->ioaddr = s->io;
     }
+
+    s->status |= NAND_IOSTATUS_READY;
 }
 
 static void glue(nand_init_, PAGE_SIZE)(NANDFlashState *s)
-- 
1.7.9.5