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linux-next/drivers/mtd/nand/gpmi-nand
Huang Shijie 995fbbf563 mtd: gpmi: add EDO feature for imx6q
When the frequency on the nand chip pins is above 33MHz,
the nand EDO(extended Data Out) timing could be applied.
The GPMI implements a Feedback read strobe to sample the read data in
the EDO timing mode.

This patch adds the EDO feature for the gpmi-nand driver.

For some onfi nand chips, the mode 4 is the fastest;
while for other onfi nand chips, the mode 5 is the fastest.
This patch only adds the support for the fastest asynchronous timing mode.
So this patch only supports the mode 4 and mode 5.

I tested several Micron's ONFI nand chips with EDO enabled,
take Micron MT29F32G08MAA for example (in mode 5, 100MHz):

1) The test result BEFORE we add the EDO feature:
	=================================================
	mtd_speedtest: MTD device: 2
	mtd_speedtest: MTD device size 209715200, eraseblock size 524288,
				page size 4096, count of eraseblocks 400,
				pages per eraseblock 128, OOB size 218
	.......................................
	mtd_speedtest: testing eraseblock read speed
	mtd_speedtest: eraseblock read speed is 3632 KiB/s
	.......................................
	mtd_speedtest: testing page read speed
	mtd_speedtest: page read speed is 3554 KiB/s
	.......................................
	mtd_speedtest: testing 2 page read speed
	mtd_speedtest: 2 page read speed is 3592 KiB/s
	.......................................
	=================================================

2) The test result AFTER we add the EDO feature:
	=================================================
	mtd_speedtest: MTD device: 2
	mtd_speedtest: MTD device size 209715200, eraseblock size 524288,
				page size 4096, count of eraseblocks 400,
				pages per eraseblock 128, OOB size 218
	.......................................
	mtd_speedtest: testing eraseblock read speed
	mtd_speedtest: eraseblock read speed is 19555 KiB/s
	.......................................
	mtd_speedtest: testing page read speed
	mtd_speedtest: page read speed is 17319 KiB/s
	.......................................
	mtd_speedtest: testing 2 page read speed
	mtd_speedtest: 2 page read speed is 18339 KiB/s
	.......................................
	=================================================

3) The read data performance is much improved by more then 5 times.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-09-29 15:56:36 +01:00
..
bch-regs.h mtd: gpmi: add gpmi support for mx6q 2012-05-13 23:22:29 -05:00
gpmi-lib.c mtd: gpmi: add EDO feature for imx6q 2012-09-29 15:56:36 +01:00
gpmi-nand.c mtd: gpmi: add EDO feature for imx6q 2012-09-29 15:56:36 +01:00
gpmi-nand.h mtd: gpmi: add EDO feature for imx6q 2012-09-29 15:56:36 +01:00
gpmi-regs.h mtd: gpmi: add a new field for HW_GPMI_CTRL1 2012-09-29 15:55:18 +01:00
Makefile mtd: add GPMI-NAND driver in the config and Makefile 2011-09-11 15:02:18 +03:00