On 08/05/2014 16:29, Lee Jones wrote:

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Define a struct containing the standard NAND timings as described in NAND
datasheets.

Signed-off-by: Boris BREZILLON <redacted>
---
 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

[...]

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+ * 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.

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+ *
+ */
+

Extra blank line.

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+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.

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+	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