mtd: spi-nor: Properly set SECT_4K for recently added flashes

Few recently added entries are missing SECT_4K flag despite of these
flashes supporting 4 KiB erase sectors and 0x20 erase command.
Also add a comment to help avoiding such mistakes in the future.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Cc: Knut Wohlrab <knut.wohlrab@de.bosch.com>
Cc: Huang Shijie <shijie.huang@intel.com>
Cc: Shengzhou Liu <shengzhou.liu@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/spi-nor/spi-nor.c

@@ -513,6 +513,13 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 /* NOTE: double check command sets and memory organization when you add
  * more nor chips.  This current list focusses on newer chips, which
  * have been converging on command sets which including JEDEC ID.
+ *
+ * All newly added entries should describe *hardware* and should use SECT_4K
+ * (or SECT_4K_PMC) if hardware supports erasing 4 KiB sectors. For usage
+ * scenarios excluding small sectors there is config option that can be
+ * disabled: CONFIG_MTD_SPI_NOR_USE_4K_SECTORS.
+ * For historical (and compatibility) reasons (before we got above config) some
+ * old entries may be missing 4K flag.
  */
 static const struct spi_device_id spi_nor_ids[] = {
 	/* Atmel -- some are (confusingly) marketed as "DataFlash" */
@@ -538,7 +545,7 @@ static const struct spi_device_id spi_nor_ids[] = {
 	{ "en25q64",    INFO(0x1c3017, 0, 64 * 1024,  128, SECT_4K) },
 	{ "en25qh128",  INFO(0x1c7018, 0, 64 * 1024,  256, 0) },
 	{ "en25qh256",  INFO(0x1c7019, 0, 64 * 1024,  512, 0) },
-	{ "en25s64",	INFO(0x1c3817, 0, 64 * 1024,  128, 0) },
+	{ "en25s64",	INFO(0x1c3817, 0, 64 * 1024,  128, SECT_4K) },
 
 	/* ESMT */
 	{ "f25l32pa", INFO(0x8c2016, 0, 64 * 1024, 64, SECT_4K) },
@@ -606,7 +613,7 @@ static const struct spi_device_id spi_nor_ids[] = {
 	{ "s70fl01gs",  INFO(0x010221, 0x4d00, 256 * 1024, 256, 0) },
 	{ "s25sl12800", INFO(0x012018, 0x0300, 256 * 1024,  64, 0) },
 	{ "s25sl12801", INFO(0x012018, 0x0301,  64 * 1024, 256, 0) },
-	{ "s25fl128s",	INFO6(0x012018, 0x4d0180, 64 * 1024, 256, SPI_NOR_QUAD_READ) },
+	{ "s25fl128s",	INFO6(0x012018, 0x4d0180, 64 * 1024, 256, SECT_4K | SPI_NOR_QUAD_READ) },
 	{ "s25fl129p0", INFO(0x012018, 0x4d00, 256 * 1024,  64, 0) },
 	{ "s25fl129p1", INFO(0x012018, 0x4d01,  64 * 1024, 256, 0) },
 	{ "s25sl004a",  INFO(0x010212,      0,  64 * 1024,   8, 0) },
@@ -617,7 +624,7 @@ static const struct spi_device_id spi_nor_ids[] = {
 	{ "s25fl008k",  INFO(0xef4014,      0,  64 * 1024,  16, SECT_4K) },
 	{ "s25fl016k",  INFO(0xef4015,      0,  64 * 1024,  32, SECT_4K) },
 	{ "s25fl064k",  INFO(0xef4017,      0,  64 * 1024, 128, SECT_4K) },
-	{ "s25fl132k",  INFO(0x014016,      0,  64 * 1024,  64, 0) },
+	{ "s25fl132k",  INFO(0x014016,      0,  64 * 1024,  64, SECT_4K) },
 	{ "s25fl164k",  INFO(0x014017,      0,  64 * 1024, 128, SECT_4K) },
 
 	/* SST -- large erase sizes are "overlays", "sectors" are 4K */