[MTD] NAND: nandsim: support subpage write

As flash cannot do 0->1 bit transitions when programming, do not do this in
the simulator too. This makes nandsim able to accept subpage writes.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 28ee78544ff2..abebcab47631 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -852,6 +852,7 @@ static void erase_sector(struct nandsim *ns)
  */
 static int prog_page(struct nandsim *ns, int num)
 {
+        int i;
         union ns_mem *mypage;
         u_char *pg_off;
 
@@ -867,7 +868,8 @@ static int prog_page(struct nandsim *ns, int num)
         }
 
         pg_off = NS_PAGE_BYTE_OFF(ns);
-        memcpy(pg_off, ns->buf.byte, num);
+        for (i = 0; i < num; i++)
+                pg_off[i] &= ns->buf.byte[i];
 
         return 0;
 }