[PATCH 29/39] mtd: nand: denali: refactor multi NAND fixup code in more generic way

From: Masahiro Yamada
Date: Sat Nov 26 2016 - 13:12:21 EST


Currently, this code expects denali->devnum == 1 or 2, but it can be
written in a more generic way, although denali->devnum should be a
power of 2.

Also, make the code more readable with devnum_shift.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

drivers/mtd/nand/denali.c | 39 +++++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 54dcd83..71bdf2a 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1476,6 +1476,7 @@ static void denali_multidev_fixup(struct denali_nand_info *denali)
{
struct nand_chip *chip = &denali->nand;
struct mtd_info *mtd = nand_to_mtd(chip);
+ int devnum_shift;

/*
* Support for multi NAND:
@@ -1484,20 +1485,30 @@ 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;
+ devnum_shift = fls(denali->devnum) - 1;
+
+ if (denali->devnum != BIT(devnum_shift)) {
+ dev_warn(denali->dev,
+ "DEVICE_CONNECTED=%d is not power of 2. Some devices will not be used.\n",
+ denali->devnum);
+ denali->devnum = BIT(devnum_shift);
+ iowrite32(denali->devnum, denali->flash_reg + DEVICES_CONNECTED);
+ }
+
+ mtd->size <<= devnum_shift;
+ mtd->erasesize <<= devnum_shift;
+ mtd->writesize <<= devnum_shift;
+ mtd->oobsize <<= devnum_shift;
+ chip->chipsize <<= devnum_shift;
+ chip->page_shift += devnum_shift;
+ chip->phys_erase_shift += devnum_shift;
+ chip->bbt_erase_shift += devnum_shift;
+ chip->chip_shift += devnum_shift;
+ chip->pagemask <<= devnum_shift;
+ chip->ecc.size <<= devnum_shift;
+ chip->ecc.bytes <<= devnum_shift;
+ chip->ecc.strength <<= devnum_shift;
+ denali->bbtskipbytes <<= devnum_shift;
}

int denali_init(struct denali_nand_info *denali)
--
2.7.4