mtd: spi-nor: store .n_banks in struct spi_nor_flash_parameter

First, fixups might want to replace the n_banks parameter, thus we need
it in the (writable) parameter struct. Secondly, this way we can have a
default in the core and just skip setting the n_banks in the flash_info
database. Most of the flashes doesn't have more than one bank.
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-7-e60548861b10@kernel.orgSigned-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

drivers/mtd/spi-nor/core.c

@@ -2862,7 +2862,7 @@ static void spi_nor_init_flags(struct spi_nor *nor)
 	if (flags & NO_CHIP_ERASE)
 		nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
 
-	if (flags & SPI_NOR_RWW && nor->info->n_banks > 1 &&
+	if (flags & SPI_NOR_RWW && nor->params->n_banks > 1 &&
 	    !nor->controller_ops)
 		nor->flags |= SNOR_F_RWW;
 }
@@ -2926,8 +2926,8 @@ static int spi_nor_late_init_params(struct spi_nor *nor)
 	if (nor->flags & SNOR_F_HAS_LOCK && !nor->params->locking_ops)
 		spi_nor_init_default_locking_ops(nor);
 
-	if (nor->info->n_banks > 1)
-		params->bank_size = div64_u64(params->size, nor->info->n_banks);
+	if (params->n_banks > 1)
+		params->bank_size = div64_u64(params->size, params->n_banks);
 
 	return 0;
 }
@@ -2997,6 +2997,7 @@ static void spi_nor_init_default_params(struct spi_nor *nor)
 	params->size = info->size;
 	params->bank_size = params->size;
 	params->page_size = info->page_size ?: SPI_NOR_DEFAULT_PAGE_SIZE;
+	params->n_banks = info->n_banks;
 
 	if (!(info->flags & SPI_NOR_NO_FR)) {
 		/* Default to Fast Read for DT and non-DT platform devices. */

drivers/mtd/spi-nor/core.h

@@ -358,6 +358,7 @@ struct spi_nor_otp {
  *			in octal DTR mode.
  * @rdsr_addr_nbytes:	dummy address bytes needed for Read Status Register
  *			command in octal DTR mode.
+ * @n_banks:		number of banks.
  * @n_dice:		number of dice in the flash memory.
  * @vreg_offset:	volatile register offset for each die.
  * @hwcaps:		describes the read and page program hardware
@@ -394,6 +395,7 @@ struct spi_nor_flash_parameter {
 	u8				addr_mode_nbytes;
 	u8				rdsr_dummy;
 	u8				rdsr_addr_nbytes;
+	u8				n_banks;
 	u8				n_dice;
 	u32				*vreg_offset;