mtd: spi-nor: spansion: Add local function to discover page size

The page size check in s28hs512t fixup can be used for s25hs/hl-t as well.
Move that to a newly created local function.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220725092505.446315-7-tudor.ambarus@microchip.com

drivers/mtd/spi-nor/spansion.c

@@ -113,6 +113,36 @@ static int cypress_nor_octal_dtr_dis(struct spi_nor *nor)
 	return 0;
 }
 
+/**
+ * cypress_nor_set_page_size() - Set page size which corresponds to the flash
+ *                               configuration.
+ * @nor:	pointer to a 'struct spi_nor'
+ *
+ * The BFPT table advertises a 512B or 256B page size depending on part but the
+ * page size is actually configurable (with the default being 256B). Read from
+ * CFR3V[4] and set the correct size.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int cypress_nor_set_page_size(struct spi_nor *nor)
+{
+	struct spi_mem_op op =
+		CYPRESS_NOR_RD_ANY_REG_OP(3, SPINOR_REG_CYPRESS_CFR3V,
+					  nor->bouncebuf);
+	int ret;
+
+	ret = spi_nor_read_any_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
+
+	if (nor->bouncebuf[0] & SPINOR_REG_CYPRESS_CFR3V_PGSZ)
+		nor->params->page_size = 512;
+	else
+		nor->params->page_size = 256;
+
+	return 0;
+}
+
 /**
  * cypress_nor_octal_dtr_enable() - Enable octal DTR on Cypress flashes.
  * @nor:		pointer to a 'struct spi_nor'
@@ -167,28 +197,7 @@ static int s28hs512t_post_bfpt_fixup(struct spi_nor *nor,
 				     const struct sfdp_parameter_header *bfpt_header,
 				     const struct sfdp_bfpt *bfpt)
 {
-	/*
-	 * The BFPT table advertises a 512B page size but the page size is
-	 * actually configurable (with the default being 256B). Read from
-	 * CFR3V[4] and set the correct size.
-	 */
-	struct spi_mem_op op =
-		CYPRESS_NOR_RD_ANY_REG_OP(3, SPINOR_REG_CYPRESS_CFR3V,
-					  nor->bouncebuf);
-	int ret;
-
-	spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
-
-	ret = spi_mem_exec_op(nor->spimem, &op);
-	if (ret)
-		return ret;
-
-	if (nor->bouncebuf[0] & SPINOR_REG_CYPRESS_CFR3V_PGSZ)
-		nor->params->page_size = 512;
-	else
-		nor->params->page_size = 256;
-
-	return 0;
+	return cypress_nor_set_page_size(nor);
 }
 
 static const struct spi_nor_fixups s28hs512t_fixups = {