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| author | Boris Brezillon <boris.brezillon@free-electrons.com> | 2016-10-01 11:24:03 +0300 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@free-electrons.com> | 2016-11-07 16:48:37 +0300 |
| commit | 6ea40a3ba93e1b14ffb349e276f9dfefc4334b99 (patch) | |
| tree | f37e804a5eecaa681957ff24739964e7bd0c55e5 /drivers/mtd | |
| parent | 204e7ecd47e26cc12d9e8e8a7e7a2eeb9573f0ba (diff) | |
| download | linux-6ea40a3ba93e1b14ffb349e276f9dfefc4334b99.tar.xz | |
mtd: nand: Wait tCCS after a column change
Drivers implementing ->cmd_ctrl() and relying on the default ->cmdfunc()
implementation usually don't wait tCCS when a column change (RNDIN or
RNDOUT) is requested.
Add an option flag to ask the core to do so (note that we keep this as
an opt-in to avoid breaking existing implementations), and make use of
the ->data_interface information is available (otherwise, wait 500ns).
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/nand_base.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index e5718e5ecf92..0acb0070280a 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -709,6 +709,25 @@ static void nand_command(struct mtd_info *mtd, unsigned int command, nand_wait_ready(mtd); } +static void nand_ccs_delay(struct nand_chip *chip) +{ + /* + * The controller already takes care of waiting for tCCS when the RNDIN + * or RNDOUT command is sent, return directly. + */ + if (!(chip->options & NAND_WAIT_TCCS)) + return; + + /* + * Wait tCCS_min if it is correctly defined, otherwise wait 500ns + * (which should be safe for all NANDs). + */ + if (chip->data_interface && chip->data_interface->timings.sdr.tCCS_min) + ndelay(chip->data_interface->timings.sdr.tCCS_min / 1000); + else + ndelay(500); +} + /** * nand_command_lp - [DEFAULT] Send command to NAND large page device * @mtd: MTD device structure @@ -773,10 +792,13 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command, case NAND_CMD_ERASE1: case NAND_CMD_ERASE2: case NAND_CMD_SEQIN: - case NAND_CMD_RNDIN: case NAND_CMD_STATUS: return; + case NAND_CMD_RNDIN: + nand_ccs_delay(chip); + return; + case NAND_CMD_RESET: if (chip->dev_ready) break; @@ -795,6 +817,8 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command, NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE); chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE); + + nand_ccs_delay(chip); return; case NAND_CMD_READ0: |