From c316f577b4b72d1a1aeb559e9b3fad20808f1ffd Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Wed, 25 Jun 2014 14:43:32 +0200 Subject: mtd: OMAP: Enable GPMC prefetch mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Martínez Reviewed-by: Guido Martínez Signed-off-by: Daniel Mack [trini: Make apply again, use 'cs' fix pointed out by Guido] Signed-off-by: Tom Rini --- doc/README.nand | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'doc') diff --git a/doc/README.nand b/doc/README.nand index e29188f1ec..dee0e00a61 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: ===== -- cgit v1.2.1