[PATCH 4/4] mtd: rawnand: gpmi: support fast edo timings for mx28

From: Dario Binacchi
Date: Tue Jan 18 2022 - 04:55:24 EST


In the i.MX28 manual (MCIMX28RM, Rev. 1, 2010) you can find an example
(15.2.4 High-Speed NAND Timing) of how to configure the GPMI controller
to manage High-Speed ​​NAND devices, so it was wrong to assume that only
i.MX6 can achieve EDO timings.

This patch has been tested on a 2048/64 byte NAND (Micron MT29F2G08ABAEAH4).
Kernel mtd tests:
- mtd_nandbiterrs
- mtd_nandecctest
- mtd_oobtest
- mtd_pagetest
- mtd_readtest
- mtd_speedtest
- mtd_stresstest
- mtd_subpagetest
- mtd_torturetest [cycles_count = 10000000]
run without errors.

Before this patch (mode 0):
---------------------------
eraseblock write speed is 2098 KiB/s
eraseblock read speed is 2680 KiB/s
page write speed is 1689 KiB/s
page read speed is 2522 KiB/s
2 page write speed is 1899 KiB/s
2 page read speed is 2579 KiB/s
erase speed is 128000 KiB/s
2x multi-block erase speed is 73142 KiB/s
4x multi-block erase speed is 204800 KiB/s
8x multi-block erase speed is 256000 KiB/s
16x multi-block erase speed is 256000 KiB/s
32x multi-block erase speed is 256000 KiB/s
64x multi-block erase speed is 256000 KiB/s

After this patch (mode 5):
-------------------------
eraseblock write speed is 3390 KiB/s
eraseblock read speed is 5688 KiB/s
page write speed is 2680 KiB/s
page read speed is 4876 KiB/s
2 page write speed is 2909 KiB/s
2 page read speed is 5224 KiB/s
erase speed is 170666 KiB/s
2x multi-block erase speed is 204800 KiB/s
4x multi-block erase speed is 256000 KiB/s
8x multi-block erase speed is 256000 KiB/s
16x multi-block erase speed is 256000 KiB/s
32x multi-block erase speed is 256000 KiB/s
64x multi-block erase speed is 256000 KiB/s

Co-developed-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Reviewed-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>

---

drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index cf35f4206030..d96899fa90b7 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -787,8 +787,8 @@ static int gpmi_setup_interface(struct nand_chip *chip, int chipnr,
if (IS_ERR(sdr))
return PTR_ERR(sdr);

- /* Only MX6 GPMI controller can reach EDO timings */
- if (sdr->tRC_min <= 25000 && !GPMI_IS_MX6(this))
+ /* Only MX28/MX6 GPMI controller can reach EDO timings */
+ if (sdr->tRC_min <= 25000 && !GPMI_IS_MX28(this) && !GPMI_IS_MX6(this))
return -ENOTSUPP;

/* Stop here if this call was just a check */
--
2.32.0