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| author | Daniel Mack <zonque@gmail.com> | 2014-06-25 14:43:32 +0200 |
|---|---|---|
| committer | Tom Rini <trini@ti.com> | 2015-01-13 11:51:23 -0500 |
| commit | c316f577b4b72d1a1aeb559e9b3fad20808f1ffd (patch) | |
| tree | 9923bfbaeae9a43482ee6838dcb0cd31a7d36e6d /doc | |
| parent | 92fa7f53f1f3f03296f8ffb14bdf1baefab83368 (diff) | |
| download | u-boot-imx-c316f577b4b72d1a1aeb559e9b3fad20808f1ffd.zip u-boot-imx-c316f577b4b72d1a1aeb559e9b3fad20808f1ffd.tar.gz u-boot-imx-c316f577b4b72d1a1aeb559e9b3fad20808f1ffd.tar.bz2 | |
mtd: OMAP: Enable GPMC prefetch mode
Enable GPMC's prefetch feature for NAND access. This speeds up NAND read
access a lot by pre-fetching contents in the background and reading them
through the FIFO address.
The current implementation has two limitations:
a) it only works in 8-bit mode
b) it only supports read access
Both is easily fixable by someone who has hardware to implement it.
Note that U-Boot code uses non word-aligned buffers to read data into, and
request read lengths that are not multiples of 4, so both partial buffers
(head and tail) have to be addressed.
Tested on AM335x hardware.
Tested-by: Guido MartÃnez <guido@vanguardiasur.com.ar>
Reviewed-by: Guido MartÃnez <guido@vanguardiasur.com.ar>
Signed-off-by: Daniel Mack <zonque@gmail.com>
[trini: Make apply again, use 'cs' fix pointed out by Guido]
Signed-off-by: Tom Rini <trini@ti.com>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.nand | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/doc/README.nand b/doc/README.nand index e29188f..dee0e00 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -304,6 +304,11 @@ Platform specific options Thus BCH16 can be supported on 4K page NAND. + CONFIG_NAND_OMAP_GPMC_PREFETCH + On OMAP platforms that use the GPMC controller + (CONFIG_NAND_OMAP_GPMC_PREFETCH), this options enables the code that + uses the prefetch mode to speed up read operations. + NOTE: ===== |