mtd: spinand: add spinand_read_cfg() helper

Put REG_CFG reading code in spinand_read_cfg().
This function will be needed by the future SPI-NAND resume ops.
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210602094913.26472-2-patrice.chotard@foss.st.com

drivers/mtd/nand/spi/core.c

@@ -138,20 +138,12 @@ int spinand_select_target(struct spinand_device *spinand, unsigned int target)
 	return 0;
 }
 
-static int spinand_init_cfg_cache(struct spinand_device *spinand)
+static int spinand_read_cfg(struct spinand_device *spinand)
 {
 	struct nand_device *nand = spinand_to_nand(spinand);
-	struct device *dev = &spinand->spimem->spi->dev;
 	unsigned int target;
 	int ret;
 
-	spinand->cfg_cache = devm_kcalloc(dev,
-					  nand->memorg.ntargets,
-					  sizeof(*spinand->cfg_cache),
-					  GFP_KERNEL);
-	if (!spinand->cfg_cache)
-		return -ENOMEM;
-
 	for (target = 0; target < nand->memorg.ntargets; target++) {
 		ret = spinand_select_target(spinand, target);
 		if (ret)
@@ -170,6 +162,21 @@ static int spinand_init_cfg_cache(struct spinand_device *spinand)
 	return 0;
 }
 
+static int spinand_init_cfg_cache(struct spinand_device *spinand)
+{
+	struct nand_device *nand = spinand_to_nand(spinand);
+	struct device *dev = &spinand->spimem->spi->dev;
+
+	spinand->cfg_cache = devm_kcalloc(dev,
+					  nand->memorg.ntargets,
+					  sizeof(*spinand->cfg_cache),
+					  GFP_KERNEL);
+	if (!spinand->cfg_cache)
+		return -ENOMEM;
+
+	return 0;
+}
+
 static int spinand_init_quad_enable(struct spinand_device *spinand)
 {
 	bool enable = false;
@@ -1117,6 +1124,10 @@ static int spinand_init(struct spinand_device *spinand)
 	if (ret)
 		goto err_free_bufs;
 
+	ret = spinand_read_cfg(spinand);
+	if (ret)
+		goto err_free_bufs;
+
 	ret = spinand_init_quad_enable(spinand);
 	if (ret)
 		goto err_free_bufs;