mtd: spi-nand: macronix: Extract the bitflip retrieval logic

With GET_STATUS commands, SPI-NAND devices can tell the status of the
last read operation, in particular if there was:
- no bitflips
- corrected bitflips
- uncorrectable bitflips

The next step then to read an ECC status register and retrieve the
amount of bitflips, when relevant, if possible. The logic used here
works well for now, but will no longer apply to continuous reads. In
order to prepare the introduction of continuous reads, let's factorize
out the code that is specific to single-page reads.

Signed-off-by: Miquel Raynal <[email protected]>
Link: https://lore.kernel.org/linux-mtd/[email protected]

Author: miquelraynal

drivers/mtd/nand/spi/macronix.c

@@ -64,12 +64,29 @@ static int macronix_get_eccsr(struct spinand_device *spinand, u8 *eccsr)
 	return 0;
 }
 
-static int macronix_ecc_get_status(struct spinand_device *spinand,
-				   u8 status)
+static int macronix_get_bf(struct spinand_device *spinand, u8 status)
 {
 	struct nand_device *nand = spinand_to_nand(spinand);
 	u8 eccsr;
 
+	/*
+	 * Let's try to retrieve the real maximum number of bitflips
+	 * in order to avoid forcing the wear-leveling layer to move
+	 * data around if it's not necessary.
+	 */
+	if (macronix_get_eccsr(spinand, spinand->scratchbuf))
+		return nanddev_get_ecc_conf(nand)->strength;
+
+	eccsr = *spinand->scratchbuf;
+	if (WARN_ON(eccsr > nanddev_get_ecc_conf(nand)->strength || !eccsr))
+		return nanddev_get_ecc_conf(nand)->strength;
+
+	return eccsr;
+}
+
+static int macronix_ecc_get_status(struct spinand_device *spinand,
+				   u8 status)
+{
 	switch (status & STATUS_ECC_MASK) {
 	case STATUS_ECC_NO_BITFLIPS:
 		return 0;
@@ -78,21 +95,7 @@ static int macronix_ecc_get_status(struct spinand_device *spinand,
 		return -EBADMSG;
 
 	case STATUS_ECC_HAS_BITFLIPS:
-		/*
-		 * Let's try to retrieve the real maximum number of bitflips
-		 * in order to avoid forcing the wear-leveling layer to move
-		 * data around if it's not necessary.
-		 */
-		if (macronix_get_eccsr(spinand, spinand->scratchbuf))
-			return nanddev_get_ecc_conf(nand)->strength;
-
-		eccsr = *spinand->scratchbuf;
-		if (WARN_ON(eccsr > nanddev_get_ecc_conf(nand)->strength ||
-			    !eccsr))
-			return nanddev_get_ecc_conf(nand)->strength;
-
-		return eccsr;
-
+		return macronix_get_bf(spinand, status);
 	default:
 		break;
 	}