Messages in this thread | | | Date | Fri, 09 May 2014 17:47:19 +0200 | From | Boris BREZILLON <> | Subject | Re: [PATCH v3 1/9] mtd: nand: define struct nand_timings |
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On 08/05/2014 16:29, Lee Jones wrote: >>> Define a struct containing the standard NAND timings as described in NAND >>> datasheets. >>> >>> Signed-off-by: Boris BREZILLON <b.brezillon.dev@gmail.com> >>> --- >>> include/linux/mtd/nand.h | 49 ++++++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 49 insertions(+) >>> >>> diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h >>> index 389b3c5..f3ff3a3 100644 >>> --- a/include/linux/mtd/nand.h >>> +++ b/include/linux/mtd/nand.h > [...] > >>> + * Parameters) >> Please document the units for these fields here. It looks like you're >> using picoseconds. > Can't we leave this open to interpretation? For instance, it's more > convenient for our driver to handle these as nano second values. > >>> + * >>> + */ >>> + >> Extra blank line. >> >>> +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 tCSD_min;
This is related to ddr2 timings, and this structure only define sdr related timings.
>>> + u32 tDH_min; >>> + u32 tDS_min; >>> + u32 tFEAT_max; >>> + u32 tIR_min; >>> + u32 tITC_max; > u32 tR_max;
Actually this one cannot be retrieved from the ONFI timing mode, you'll have to read bytes 137 and 138 in the parameter page. Hence I got rid of it in the first place. Then I considered adding all those missing timings in another structure (see [1]).
I noticed you posted something similar on the MTD mailing list (and Lucas was waiting for the feature too). Could we work together to propose something that fulfills all our needs ?
Here's what I need: - get detailled timings to be able to configure the sunxi NAND controller appropriately - a way to get these timings on non-ONFi NANDs (the proposed solution is exposing the closest supported ONFI timing mode in the NAND chip DT node, but I'm open to any new proposal).
Best Regards,
Boris
[1] http://lists.infradead.org/pipermail/linux-mtd/2014-March/052525.html
-- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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