summaryrefslogtreecommitdiff
path: root/include/linux/mtd
diff options
context:
space:
mode:
authorMiquel Raynal <miquel.raynal@bootlin.com>2021-05-05 23:37:41 +0200
committerMiquel Raynal <miquel.raynal@bootlin.com>2021-05-26 10:43:54 +0200
commitd7a773e8812bcf7a5412e4baebc6eb1c11242551 (patch)
tree02cd55f67063aabbebe49a0b04655f33249c8f89 /include/linux/mtd
parentfee9c6d8f098f7054f97ec1dbcfb42a2a3238f23 (diff)
mtd: rawnand: Access SDR and NV-DDR timings through a common macro
Most timings related to the bus timings are different between SDR and NV-DDR. However, we identified 9 individual timings which are more related to the NAND chip internals. These are common between the two interface types. Fortunately, only these common timings are being shared through the NAND core and its ->exec_op() interface, which allows the writing of a simple macro checking the interface type and depending on it, returning either the relevant SDR timing or the NV-DDR timing. This is the purpose of the NAND_COMMON_TIMING_PS() macro. As all this is evaluated at build time, one will immediately be notified in case a non common timing is being accessed through this macro. Two handy macros are also inserted at the same time, which use PSEC_TO_NSEC or PSEC_TO_MSEC so that it is very easy to return timings in milli-, nano- or pico-seconds, as usually requested by the internal API. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20210505213750.257417-14-miquel.raynal@bootlin.com
Diffstat (limited to 'include/linux/mtd')
-rw-r--r--include/linux/mtd/rawnand.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index a53a1543d1d4..89b9c52c7387 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -557,6 +557,34 @@ struct nand_nvddr_timings {
u32 tWW_min;
};
+/*
+ * While timings related to the data interface itself are mostly different
+ * between SDR and NV-DDR, timings related to the internal chip behavior are
+ * common. IOW, the following entries which describe the internal delays have
+ * the same definition and are shared in both SDR and NV-DDR timing structures:
+ * - tADL_min
+ * - tBERS_max
+ * - tCCS_min
+ * - tFEAT_max
+ * - tPROG_max
+ * - tR_max
+ * - tRR_min
+ * - tRST_max
+ * - tWB_max
+ *
+ * The below macros return the value of a given timing, no matter the interface.
+ */
+#define NAND_COMMON_TIMING_PS(conf, timing_name) \
+ nand_interface_is_sdr(conf) ? \
+ nand_get_sdr_timings(conf)->timing_name : \
+ nand_get_nvddr_timings(conf)->timing_name
+
+#define NAND_COMMON_TIMING_MS(conf, timing_name) \
+ PSEC_TO_MSEC(NAND_COMMON_TIMING_PS((conf), timing_name))
+
+#define NAND_COMMON_TIMING_NS(conf, timing_name) \
+ PSEC_TO_NSEC(NAND_COMMON_TIMING_PS((conf), timing_name))
+
/**
* enum nand_interface_type - NAND interface type
* @NAND_SDR_IFACE: Single Data Rate interface