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authorJosh Wu <josh.wu@atmel.com>2013-08-05 19:14:37 +0800
committerDavid Woodhouse <David.Woodhouse@intel.com>2013-08-05 21:07:51 +0100
commit6054d4d56307839bffabb687767c24d5ff62563b (patch)
treecb34b9efc666b617894df1722ae03b60e20587da /Documentation/devicetree/bindings/mtd
parent1ae9c092efcca18876921548b2d16cf7c4b53fda (diff)
mtd: atmel_nand: enable Nand Flash Controller (NFC) write via sram
This patch enable writing nand flash via NFC SRAM. It will minimize the CPU overhead. The SRAM write only support ECC_NONE and ECC_HW with PMECC. To enable this NFC write by SRAM feature, you can add a string in dts under NFC driver node. This driver has been tested on SAMA5D3X-EK with JFFS2, YAFFS2, UBIFS and mtd-utils. Here is part of mtd_speedtest (writing test) result, compare with non-NFC writing, it reduces %65 cpu load with loss %12 speed. - commands use to test: # insmod /mnt/mtd_speedtest.ko dev=2 & # top -n 30 -d 1 | grep speedtest - test result: ================================================= mtd_speedtest: MTD device: 2 mtd_speedtest: MTD device size 41943040, eraseblock size 131072, page size 2048, count of eraseblocks 320, pages per eraseblock 64, OOB size 64 mtd_speedtest: testing eraseblock write speed 509 495 root D 1164 0% 7% insmod /mnt/mtd_speedtest.ko dev=2 509 495 root D 1164 0% 8% insmod /mnt/mtd_speedtest.ko dev=2 509 495 root R 1164 0% 5% insmod /mnt/mtd_speedtest.ko dev=2 mtd_speedtest: eraseblock write speed is 5194 KiB/s mtd_speedtest: testing page write speed 509 495 root D 1164 0% 32% insmod /mnt/mtd_speedtest.ko dev=2 509 495 root D 1164 0% 27% insmod /mnt/mtd_speedtest.ko dev=2 509 495 root D 1164 0% 25% insmod /mnt/mtd_speedtest.ko dev=2 509 495 root D 1164 0% 30% insmod /mnt/mtd_speedtest.ko dev=2 mtd_speedtest: page write speed is 5024 KiB/s Signed-off-by: Josh Wu <josh.wu@atmel.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'Documentation/devicetree/bindings/mtd')
-rw-r--r--Documentation/devicetree/bindings/mtd/atmel-nand.txt2
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index 5d8b7d5c914d..c4728839d0c1 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -36,6 +36,8 @@ Optional properties:
- reg : should specify the address and size used for NFC command registers,
NFC registers and NFC Sram. NFC Sram address and size can be absent
if don't want to use it.
+ - Optional properties:
+ - atmel,write-by-sram: boolean to enable NFC write by sram.
Examples:
nand0: nand@40000000,0 {