mtd: spi-nor: spansion: switch set_octal_dtr method to use vreg_offset

All the Infineon flashes that currently support octal DTR mode
define the optional SCCR SFDP table, thus all retrieve vreg_offset.
Switch all the available octal DTR Infineon flashes to use the
volatile register offset to set the configuration registers. The goal
is to have a single pair of methods for both single/multi-chip package
devices.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Link: https://lore.kernel.org/r/20230726075257.12985-5-tudor.ambarus@linaro.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

Author: Kuwano-san

drivers/mtd/spi-nor/spansion.c

@@ -6,6 +6,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/device.h>
+#include <linux/errno.h>
 #include <linux/mtd/spi-nor.h>
 
 #include "core.h"
@@ -37,8 +38,6 @@
 	(SPINOR_REG_CYPRESS_VREG + SPINOR_REG_CYPRESS_CFR3)
 #define SPINOR_REG_CYPRESS_CFR3_PGSZ		BIT(4) /* Page size. */
 #define SPINOR_REG_CYPRESS_CFR5			0x6
-#define SPINOR_REG_CYPRESS_CFR5V					\
-	(SPINOR_REG_CYPRESS_VREG + SPINOR_REG_CYPRESS_CFR5)
 #define SPINOR_REG_CYPRESS_CFR5_BIT6		BIT(6)
 #define SPINOR_REG_CYPRESS_CFR5_DDR		BIT(1)
 #define SPINOR_REG_CYPRESS_CFR5_OPI		BIT(0)
@@ -202,14 +201,18 @@ static int cypress_nor_set_octal_dtr_bits(struct spi_nor *nor, u64 addr)
 
 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;
 
-	ret = cypress_nor_set_memlat(nor, SPINOR_REG_CYPRESS_CFR2V);
+	addr = params->vreg_offset[0] + SPINOR_REG_CYPRESS_CFR2;
+	ret = cypress_nor_set_memlat(nor, addr);
 	if (ret)
 		return ret;
 
-	ret = cypress_nor_set_octal_dtr_bits(nor, SPINOR_REG_CYPRESS_CFR5V);
+	addr = params->vreg_offset[0] + SPINOR_REG_CYPRESS_CFR5;
+	ret = cypress_nor_set_octal_dtr_bits(nor, addr);
 	if (ret)
 		return ret;
 
@@ -247,9 +250,11 @@ 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)
 {
 	u8 *buf = nor->bouncebuf;
+	u64 addr;
 	int ret;
 
-	ret = cypress_nor_set_single_spi_bits(nor, SPINOR_REG_CYPRESS_CFR5V);
+	addr = nor->params->vreg_offset[0] + SPINOR_REG_CYPRESS_CFR5;
+	ret = cypress_nor_set_single_spi_bits(nor, addr);
 	if (ret)
 		return ret;
 
@@ -714,7 +719,15 @@ static int s28hx_t_post_bfpt_fixup(struct spi_nor *nor,
 
 static int s28hx_t_late_init(struct spi_nor *nor)
 {
-	nor->params->set_octal_dtr = cypress_nor_set_octal_dtr;
+	struct spi_nor_flash_parameter *params = nor->params;
+
+	if (!params->n_dice || !params->vreg_offset) {
+		dev_err(nor->dev, "%s failed. The volatile register offset could not be retrieved from SFDP.\n",
+			__func__);
+		return -EOPNOTSUPP;
+	}
+
+	params->set_octal_dtr = cypress_nor_set_octal_dtr;
 	cypress_nor_ecc_init(nor);
 
 	return 0;