mtd: nand: introduce NAND_ROW_ADDR_3 flag

Several drivers check ->chipsize to see if the third row address cycle
is needed.  Instead of embedding magic sizes such as 32MB, 128MB in
drivers, introduce a new flag NAND_ROW_ADDR_3 for clean-up.  Since
nand_scan_ident() knows well about the device, it can handle this
properly.  The flag is set if the row address bit width is greater
than 16.

Delete comments such as "One more address cycle for ..." because
intention is now clear enough from the code.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Wenyou Yang <wenyou.yang@microchip.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Linux commit: 14157f861437ebe2d624b0a845b91bbdf8ca9a2d]

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 77a3f16..aca3231 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -634,8 +634,7 @@ static void nand_command(struct mtd_info *mtd, unsigned int command,
                chip->cmd_ctrl(mtd, page_addr, ctrl);
                ctrl &= ~NAND_CTRL_CHANGE;
                chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
-               /* One more address cycle for devices > 32MiB */
-               if (chip->chipsize > (32 << 20))
+               if (chip->options & NAND_ROW_ADDR_3)
                        chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
        }
        chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
@@ -729,8 +728,7 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
                        chip->cmd_ctrl(mtd, page_addr, ctrl);
                        chip->cmd_ctrl(mtd, page_addr >> 8,
                                       NAND_NCE | NAND_ALE);
-                       /* One more address cycle for devices > 128MiB */
-                       if (chip->chipsize > (128 << 20))
+                       if (chip->options & NAND_ROW_ADDR_3)
                                chip->cmd_ctrl(mtd, page_addr >> 16,
                                               NAND_NCE | NAND_ALE);
                }
@@ -3889,6 +3887,9 @@ ident_done:
                chip->chip_shift += 32 - 1;
        }
 
+       if (chip->chip_shift - chip->page_shift > 16)
+               chip->options |= NAND_ROW_ADDR_3;
+
        chip->badblockbits = 8;
        chip->erase = single_erase;
 

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 150e3b8..d1db34c 100644 (file)
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -204,6 +204,9 @@ typedef enum {
  */
 #define NAND_NEED_SCRAMBLING   0x00002000
 
+/* Device needs 3rd row address cycle */
+#define NAND_ROW_ADDR_3                0x00004000
+
 /* Options valid for Samsung large page devices */
 #define NAND_SAMSUNG_LP_OPTIONS NAND_CACHEPRG