mtd: nand: define struct nand_timings

Define a struct containing the standard NAND timings as described in NAND
datasheets.
Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

include/linux/mtd/nand.h

@@ -948,4 +948,53 @@ static inline int jedec_feature(struct nand_chip *chip)
 	return chip->jedec_version ? le16_to_cpu(chip->jedec_params.features)
 		: 0;
 }
+
+/**
+ * struct nand_sdr_timings - SDR NAND chip timings
+ *
+ * This struct defines the timing requirements of a SDR NAND chip.
+ * These informations can be found in every NAND datasheets and the timings
+ * meaning are described in the ONFI specifications:
+ * www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf (chapter 4.15 Timing
+ * Parameters)
+ *
+ * All these timings are expressed in picoseconds.
+ */
+
+struct nand_sdr_timings {
+	u32 tALH_min;
+	u32 tADL_min;
+	u32 tALS_min;
+	u32 tAR_min;
+	u32 tCEA_max;
+	u32 tCEH_min;
+	u32 tCH_min;
+	u32 tCHZ_max;
+	u32 tCLH_min;
+	u32 tCLR_min;
+	u32 tCLS_min;
+	u32 tCOH_min;
+	u32 tCS_min;
+	u32 tDH_min;
+	u32 tDS_min;
+	u32 tFEAT_max;
+	u32 tIR_min;
+	u32 tITC_max;
+	u32 tRC_min;
+	u32 tREA_max;
+	u32 tREH_min;
+	u32 tRHOH_min;
+	u32 tRHW_min;
+	u32 tRHZ_max;
+	u32 tRLOH_min;
+	u32 tRP_min;
+	u32 tRR_min;
+	u64 tRST_max;
+	u32 tWB_max;
+	u32 tWC_min;
+	u32 tWH_min;
+	u32 tWHR_min;
+	u32 tWP_min;
+	u32 tWW_min;
+};
 #endif /* __LINUX_MTD_NAND_H */