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mtd: nand: vf610_nfc: Freescale NFC for VF610, MPC5125 and others
This driver supports Freescale NFC (NAND flash controller) found on
Vybrid (VF610), MPC5125, MCF54418 and Kinetis K70. The driver has
been tested using 8-bit and 16-bit NAND interface on the ARM based
Vybrid SoC VF500 and VF610 platform.
parameter page reading.
Limitations:
- Untested on MPC5125 and M54418.
- DMA and pipelining not used.
- 2K pages or less.
- No chip select, one NAND chip per controller.
- No hardware ECC.
Some paths have been hand-optimized and evaluated by measurements
made using mtd_speedtest.ko on a 100MB MTD partition.
Colibri VF50
eb write % eb read % page write % page read %
rel/opt 5175 11537 4560 11039
opt 5164 -0.21 11420 -1.01 4737 +3.88 10918 -1.10
none 5113 -1.20 11352 -1.60 4490 -1.54 10865 -1.58
Colibri VF61
eb write % eb read % page write % page read %
rel/opt 5766 13096 5459 12846
opt 5883 +2.03 13064 -0.24 5561 +1.87 12802 -0.34
none 5701 -1.13 12980 -0.89 5488 +0.53 12735 -0.86
rel = using readl_relaxed/writel_relaxed in optimized paths
opt = hand-optimized by combining multiple accesses into one read/write
The measurements have not been statistically verfied, hence use them
with care. The author came to the conclusion that using the relaxed
variants of readl/writel are not worth the additional code.
Signed-off-by: Bill Pringlemeir <bpringlemeir@nbsps.com>
Tested-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Alexey Klimov <klimov.linux@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>