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| author | Miquel Raynal <miquel.raynal@bootlin.com> | 2020-05-29 13:13:09 +0200 |
|---|---|---|
| committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2020-06-26 08:35:06 +0200 |
| commit | 98d6979aa898239ec2faa10467c338a808e1287e (patch) | |
| tree | c7e638d98c3d96d02e02e6cba79157f597f5d48a | |
| parent | fcaab3b26d2534ec9f227810975ad220823ac578 (diff) | |
| download | linux-98d6979aa898239ec2faa10467c338a808e1287e.tar.bz2 | |
mtd: rawnand: timings: Add a helper to find the closest ONFI mode
Vendors are allowed to provide their own set of timings. In this case,
we provide a way to derive the "closest" timing mode so that, if the
NAND controller does not support tweaking these parameters, it will be
able to configure itself anyway.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200529111322.7184-16-miquel.raynal@bootlin.com
| -rw-r--r-- | drivers/mtd/nand/raw/internals.h | 2 | ||||
| -rw-r--r-- | drivers/mtd/nand/raw/nand_timings.c | 47 |
2 files changed, 49 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/internals.h b/drivers/mtd/nand/raw/internals.h index bd10ec92f04a..f851ed210d70 100644 --- a/drivers/mtd/nand/raw/internals.h +++ b/drivers/mtd/nand/raw/internals.h @@ -88,6 +88,8 @@ int onfi_fill_data_interface(struct nand_chip *chip, struct nand_data_interface *iface, enum nand_data_interface_type type, unsigned int timing_mode); +unsigned int +onfi_find_closest_sdr_mode(const struct nand_sdr_timings *spec_timings); int nand_get_features(struct nand_chip *chip, int addr, u8 *subfeature_param); int nand_set_features(struct nand_chip *chip, int addr, u8 *subfeature_param); int nand_read_page_raw_notsupp(struct nand_chip *chip, u8 *buf, diff --git a/drivers/mtd/nand/raw/nand_timings.c b/drivers/mtd/nand/raw/nand_timings.c index 08dc381349fa..b089f2dc5f23 100644 --- a/drivers/mtd/nand/raw/nand_timings.c +++ b/drivers/mtd/nand/raw/nand_timings.c @@ -274,6 +274,53 @@ static const struct nand_data_interface onfi_sdr_timings[] = { }; /** + * onfi_find_closest_sdr_mode - Derive the closest ONFI SDR timing mode given a + * set of timings + * @spec_timings: the timings to challenge + */ +unsigned int +onfi_find_closest_sdr_mode(const struct nand_sdr_timings *spec_timings) +{ + const struct nand_sdr_timings *onfi_timings; + int mode; + + for (mode = ARRAY_SIZE(onfi_sdr_timings) - 1; mode > 0; mode--) { + onfi_timings = &onfi_sdr_timings[mode].timings.sdr; + + if (spec_timings->tCCS_min <= onfi_timings->tCCS_min && + spec_timings->tADL_min <= onfi_timings->tADL_min && + spec_timings->tALH_min <= onfi_timings->tALH_min && + spec_timings->tALS_min <= onfi_timings->tALS_min && + spec_timings->tAR_min <= onfi_timings->tAR_min && + spec_timings->tCEH_min <= onfi_timings->tCEH_min && + spec_timings->tCH_min <= onfi_timings->tCH_min && + spec_timings->tCLH_min <= onfi_timings->tCLH_min && + spec_timings->tCLR_min <= onfi_timings->tCLR_min && + spec_timings->tCLS_min <= onfi_timings->tCLS_min && + spec_timings->tCOH_min <= onfi_timings->tCOH_min && + spec_timings->tCS_min <= onfi_timings->tCS_min && + spec_timings->tDH_min <= onfi_timings->tDH_min && + spec_timings->tDS_min <= onfi_timings->tDS_min && + spec_timings->tIR_min <= onfi_timings->tIR_min && + spec_timings->tRC_min <= onfi_timings->tRC_min && + spec_timings->tREH_min <= onfi_timings->tREH_min && + spec_timings->tRHOH_min <= onfi_timings->tRHOH_min && + spec_timings->tRHW_min <= onfi_timings->tRHW_min && + spec_timings->tRLOH_min <= onfi_timings->tRLOH_min && + spec_timings->tRP_min <= onfi_timings->tRP_min && + spec_timings->tRR_min <= onfi_timings->tRR_min && + spec_timings->tWC_min <= onfi_timings->tWC_min && + spec_timings->tWH_min <= onfi_timings->tWH_min && + spec_timings->tWHR_min <= onfi_timings->tWHR_min && + spec_timings->tWP_min <= onfi_timings->tWP_min && + spec_timings->tWW_min <= onfi_timings->tWW_min) + return mode; + } + + return 0; +} + +/** * onfi_fill_data_interface - Initialize a data interface from a given ONFI mode * @chip: The NAND chip * @iface: The data interface to fill |