mtd: spi-nor: spansion: add MCP support in set_octal_dtr()

Infineon multi-chip package (MCP) devices require the Octal DTR
configuraion to be set on each die. We can access to configuration
registers in each die by using params->n_dice and params->vreg_offset[]
populated from SFDP. Add MCP support in set_octal_dtr().

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Link: https://lore.kernel.org/r/20230726075257.12985-7-tudor.ambarus@linaro.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

Author: Kuwano-san

drivers/mtd/spi-nor/spansion.c

@@ -204,17 +204,19 @@ static int cypress_nor_octal_dtr_en(struct spi_nor *nor)
 	const struct spi_nor_flash_parameter *params = nor->params;
 	u8 *buf = nor->bouncebuf;
 	u64 addr;
-	int ret;
+	int i, ret;
 
-	addr = params->vreg_offset[0] + SPINOR_REG_CYPRESS_CFR2;
-	ret = cypress_nor_set_memlat(nor, addr);
-	if (ret)
-		return ret;
+	for (i = 0; i < params->n_dice; i++) {
+		addr = params->vreg_offset[i] + SPINOR_REG_CYPRESS_CFR2;
+		ret = cypress_nor_set_memlat(nor, addr);
+		if (ret)
+			return ret;
 
-	addr = params->vreg_offset[0] + SPINOR_REG_CYPRESS_CFR5;
-	ret = cypress_nor_set_octal_dtr_bits(nor, addr);
-	if (ret)
-		return ret;
+		addr = params->vreg_offset[i] + SPINOR_REG_CYPRESS_CFR5;
+		ret = cypress_nor_set_octal_dtr_bits(nor, addr);
+		if (ret)
+			return ret;
+	}
 
 	/* Read flash ID to make sure the switch was successful. */
 	ret = spi_nor_read_id(nor, nor->addr_nbytes, 3, buf,
@@ -249,14 +251,17 @@ static int cypress_nor_set_single_spi_bits(struct spi_nor *nor, u64 addr)
 
 static int cypress_nor_octal_dtr_dis(struct spi_nor *nor)
 {
+	const struct spi_nor_flash_parameter *params = nor->params;
 	u8 *buf = nor->bouncebuf;
 	u64 addr;
-	int ret;
+	int i, ret;
 
-	addr = nor->params->vreg_offset[0] + SPINOR_REG_CYPRESS_CFR5;
-	ret = cypress_nor_set_single_spi_bits(nor, addr);
-	if (ret)
-		return ret;
+	for (i = 0; i < params->n_dice; i++) {
+		addr = params->vreg_offset[i] + SPINOR_REG_CYPRESS_CFR5;
+		ret = cypress_nor_set_single_spi_bits(nor, addr);
+		if (ret)
+			return ret;
+	}
 
 	/* Read flash ID to make sure the switch was successful. */
 	ret = spi_nor_read_id(nor, 0, 0, buf, SNOR_PROTO_1_1_1);