atmel_nand: Add 32 bit ecc support for sama5d2 chip

Also if minimum ecc requirment is bigger then what we support, then just
use our maxium pmecc support.
But it is not safe, so we'll output a warning about this.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Reviewed-by: Andreas Bießmann <andreas.devel@googlemail.com>

drivers/mtd/nand/atmel_nand.c

@@ -80,6 +80,7 @@ static struct nand_ecclayout atmel_pmecc_oobinfo;
  *                8-bits                13-bytes                 14-bytes
  *               12-bits                20-bytes                 21-bytes
  *               24-bits                39-bytes                 42-bytes
+ *               32-bits                52-bytes                 56-bytes
  */
 static int pmecc_get_ecc_bytes(int cap, int sector_size)
 {
@@ -638,6 +639,9 @@ static void atmel_pmecc_core_init(struct mtd_info *mtd)
 	case 24:
 		val = PMECC_CFG_BCH_ERR24;
 		break;
+	case 32:
+		val = PMECC_CFG_BCH_ERR32;
+		break;
 	}
 
 	if (host->pmecc_sector_size == 512)
@@ -723,7 +727,11 @@ static int pmecc_choose_ecc(struct atmel_nand_host *host,
 		else if (*cap <= 24)
 			host->pmecc_corr_cap = 24;
 		else
-			return -EINVAL;
+#ifdef CONFIG_SAMA5D2
+			host->pmecc_corr_cap = 32;
+#else
+			host->pmecc_corr_cap = 24;
+#endif
 	}
 	if (host->pmecc_sector_size == 0) {
 		/* use the most fitable sector size (the near smaller one ) */