mtd: spi-nor: default page_size to 256 bytes

The INFO() macro always set the page_size to 256 bytes. Make that an
optional parameter. This default is a sane one for all older flashes,
newer ones will set the page size by its SFDP tables anyway.
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-v3-6-e60548861b10@kernel.orgSigned-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

drivers/mtd/spi-nor/core.c

@@ -2018,11 +2018,6 @@ static const struct spi_nor_manufacturer *manufacturers[] = {
 static const struct flash_info spi_nor_generic_flash = {
 	.name = "spi-nor-generic",
 	.n_banks = 1,
-	/*
-	 * JESD216 rev A doesn't specify the page size, therefore we need a
-	 * sane default.
-	 */
-	.page_size = 256,
 	.parse_sfdp = true,
 };
 
@@ -3001,7 +2996,7 @@ static void spi_nor_init_default_params(struct spi_nor *nor)
 	params->writesize = 1;
 	params->size = info->size;
 	params->bank_size = params->size;
-	params->page_size = info->page_size;
+	params->page_size = info->page_size ?: SPI_NOR_DEFAULT_PAGE_SIZE;
 
 	if (!(info->flags & SPI_NOR_NO_FR)) {
 		/* Default to Fast Read for DT and non-DT platform devices. */

drivers/mtd/spi-nor/core.h

@@ -10,6 +10,11 @@
 #include "sfdp.h"
 
 #define SPI_NOR_MAX_ID_LEN	6
+/*
+ * 256 bytes is a sane default for most older flashes. Newer flashes will
+ * have the page size defined within their SFDP tables.
+ */
+#define SPI_NOR_DEFAULT_PAGE_SIZE 256
 
 /* Standard SPI NOR flash operations. */
 #define SPI_NOR_READID_OP(naddr, ndummy, buf, len)			\
@@ -447,7 +452,7 @@ struct spi_nor_fixups {
  * @sector_size:    the size listed here is what works with SPINOR_OP_SE, which
  *                  isn't necessarily called a "sector" by the vendor.
  * @n_banks:        the number of banks.
- * @page_size:      the flash's page size.
+ * @page_size:      (optional) the flash's page size. Defaults to 256.
  * @addr_nbytes:    number of address bytes to send.
  *
  * @parse_sfdp:     true when flash supports SFDP tables. The false value has no
@@ -558,7 +563,6 @@ struct flash_info {
 #define SPI_NOR_GEOMETRY(_sector_size, _n_sectors, _n_banks)		\
 	.size = (_sector_size) * (_n_sectors),				\
 	.sector_size = (_sector_size),					\
-	.page_size = 256,						\
 	.n_banks = (_n_banks)
 
 /* Used when the "_ext_id" is two bytes at most */