mtd: jz4780_nand: replace if/else blocks with switch/case

Using switch/case helps make this logic more clear and more robust. With
this structure:

 * it's clear that this driver only support ECC_{HW,SOFT,SOFT_BCH}; and

 * we can sanely handle new ECC unsupported modes (right now, this code
   makes incorrect assumptions about the possible values in the
   nand_ecc_modes_t enum; e.g., what happens with NAND_ECC_HW_OOB_FIRST?)

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Harvey Hunt <harvey.hunt@imgtec.com>
Acked-by: Harvey Hunt <harvey.hunt@imgtec.com>

diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
index 6156c55..e1c016c 100644 (file)
--- a/drivers/mtd/nand/jz4780_nand.c
+++ b/drivers/mtd/nand/jz4780_nand.c
@@ -171,29 +171,33 @@ static int jz4780_nand_init_ecc(struct jz4780_nand_chip *nand, struct device *de
        chip->ecc.bytes = fls((1 + 8) * chip->ecc.size) *
                                (chip->ecc.strength / 8);
 
-       if (nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
+       switch (chip->ecc.mode) {
+       case NAND_ECC_HW:
+               if (!nfc->bch) {
+                       dev_err(dev, "HW BCH selected, but BCH controller not found\n");
+                       return -ENODEV;
+               }
+
                chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
                chip->ecc.calculate = jz4780_nand_ecc_calculate;
                chip->ecc.correct = jz4780_nand_ecc_correct;
-       } else if (!nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
-               dev_err(dev, "HW BCH selected, but BCH controller not found\n");
-               return -ENODEV;
-       }
-
-       if (chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
-               dev_err(dev, "ECC HW syndrome not supported\n");
-               return -EINVAL;
-       }
-
-       if (chip->ecc.mode != NAND_ECC_NONE)
+               /* fall through */
+       case NAND_ECC_SOFT:
+       case NAND_ECC_SOFT_BCH:
                dev_info(dev, "using %s (strength %d, size %d, bytes %d)\n",
                        (nfc->bch) ? "hardware BCH" : "software ECC",
                        chip->ecc.strength, chip->ecc.size, chip->ecc.bytes);
-       else
+               break;
+       case NAND_ECC_NONE:
                dev_info(dev, "not using ECC\n");
+               break;
+       default:
+               dev_err(dev, "ECC mode %d not supported\n", chip->ecc.mode);
+               return -EINVAL;
+       }
 
-       /* The NAND core will generate the ECC layout. */
-       if (chip->ecc.mode == NAND_ECC_SOFT || chip->ecc.mode == NAND_ECC_SOFT_BCH)
+       /* The NAND core will generate the ECC layout for SW ECC */
+       if (chip->ecc.mode != NAND_ECC_HW)
                return 0;
 
        /* Generate ECC layout. ECC codes are right aligned in the OOB area. */