mtd: nand: support ONFI timing mode retrieval for non-ONFI

drivers/mtd/nand/nand_base.c

@@ -3776,6 +3776,7 @@ static bool find_full_id_nand(struct mtd_info *mtd, struct nand_chip *chip,
 		chip->options |= type->options;
 		chip->ecc_strength_ds = NAND_ECC_STRENGTH(type);
 		chip->ecc_step_ds = NAND_ECC_STEP(type);
+		chip->onfi_timing_mode_ds = type->onfi_timing_mode_ds;
 
 		*busw = type->options & NAND_BUSWIDTH_16;
 

include/linux/mtd/nand.h

@@ -635,6 +635,7 @@ struct nand_buffers {
  * @ecc_step_ds:	[INTERN] ECC step required by the @ecc_strength_ds,
  *                      also from the datasheet. It is the recommended ECC step
  *			size, if known; if unknown, set to zero.
+ * @onfi_timing_mode_ds:[INTERN] ONFI timing mode deduced from datasheet.
  * @numchips:		[INTERN] number of physical chips
  * @chipsize:		[INTERN] the size of one chip for multichip arrays
  * @pagemask:		[INTERN] page number mask = number of (pages / chip) - 1
@@ -727,6 +728,7 @@ struct nand_chip {
 	uint8_t bits_per_cell;
 	uint16_t ecc_strength_ds;
 	uint16_t ecc_step_ds;
+	int onfi_timing_mode_ds;
 	int badblockpos;
 	int badblockbits;
 
@@ -831,6 +833,10 @@ struct nand_chip {
  *               @ecc_step_ds in nand_chip{}, also from the datasheet.
  *               For example, the "4bit ECC for each 512Byte" can be set with
  *               NAND_ECC_INFO(4, 512).
+ * @onfi_timing_mode_ds: the ONFI timing mode supported by this NAND chip. This
+ *                       should be deduced from timings described in the
+ *                       datasheet.
+ *
  */
 struct nand_flash_dev {
 	char *name;
@@ -851,6 +857,7 @@ struct nand_flash_dev {
 		uint16_t strength_ds;
 		uint16_t step_ds;
 	} ecc;
+	int onfi_timing_mode_ds;
 };
 
 /**