mtd: nand: denali: simplify multi device fixup code

The available configuration of the IP bus width is x8 or x16, so the
possible value for denali->devnum is 1 or 2.

If the value is 1, there is nothing to do.  Fixup parameters only
when denali->devnum is 2.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

1 files changed, 30 insertions, 16 deletions

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 2b5edd39248b..e1c45bf2656d 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1403,7 +1403,7 @@ static void denali_drv_init(struct denali_nand_info *denali)
         denali->irq_status = 0;
 }
 
-static void denali_multidev_fixup(struct denali_nand_info *denali)
+static int denali_multidev_fixup(struct denali_nand_info *denali)
 {
         struct nand_chip *chip = &denali->nand;
         struct mtd_info *mtd = nand_to_mtd(chip);
@@ -1417,20 +1417,32 @@ static void denali_multidev_fixup(struct denali_nand_info *denali)
          */
         denali->devnum = ioread32(denali->flash_reg + DEVICES_CONNECTED);
 
-        mtd->size <<= denali->devnum - 1;
-        mtd->erasesize <<= denali->devnum - 1;
-        mtd->writesize <<= denali->devnum - 1;
-        mtd->oobsize <<= denali->devnum - 1;
-        chip->chipsize <<= denali->devnum - 1;
-        chip->page_shift += denali->devnum - 1;
-        chip->phys_erase_shift += denali->devnum - 1;
-        chip->bbt_erase_shift += denali->devnum - 1;
-        chip->chip_shift += denali->devnum - 1;
-        chip->pagemask <<= denali->devnum - 1;
-        chip->ecc.size *= denali->devnum;
-        chip->ecc.bytes *= denali->devnum;
-        chip->ecc.strength *= denali->devnum;
-        denali->bbtskipbytes *= denali->devnum;
+        if (denali->devnum == 1)
+                return 0;
+
+        if (denali->devnum != 2) {
+                dev_err(denali->dev, "unsupported number of devices %d\n",
+                        denali->devnum);
+                return -EINVAL;
+        }
+
+        /* 2 chips in parallel */
+        mtd->size <<= 1;
+        mtd->erasesize <<= 1;
+        mtd->writesize <<= 1;
+        mtd->oobsize <<= 1;
+        chip->chipsize <<= 1;
+        chip->page_shift += 1;
+        chip->phys_erase_shift += 1;
+        chip->bbt_erase_shift += 1;
+        chip->chip_shift += 1;
+        chip->pagemask <<= 1;
+        chip->ecc.size <<= 1;
+        chip->ecc.bytes <<= 1;
+        chip->ecc.strength <<= 1;
+        denali->bbtskipbytes <<= 1;
+
+        return 0;
 }
 
 int denali_init(struct denali_nand_info *denali)
@@ -1568,7 +1580,9 @@ int denali_init(struct denali_nand_info *denali)
         chip->ecc.write_oob = denali_write_oob;
         chip->erase = denali_erase;
 
-        denali_multidev_fixup(denali);
+        ret = denali_multidev_fixup(denali);
+        if (ret)
+                goto failed_req_irq;
 
         ret = nand_scan_tail(mtd);
         if (ret)