From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Thu, 5 Dec 2013 21:22:04 +0000 (+0100)
Subject: mtd: nand: don't use {read,write}_buf for 8-bit transfers
X-Git-Tag: v3.14-rc1~65^2~14
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=05f7835975dad6b3b517f9e23415985e648fb875;p=pandora-kernel.git

mtd: nand: don't use {read,write}_buf for 8-bit transfers

According to the Open NAND Flash Interface Specification (ONFI) Revision
3.1 "Parameters are always transferred on the lower 8-bits of the data
bus." for the Get Features and Set Features commands.

So using read_buf and write_buf is wrong for 16-bit wide nand chips as
they use I/O[15:0]. The Get Features command is easily fixed using 4
times the read_byte callback. For Set Features implement a new
overwritable callback "write_byte". Still I expect the default to work
just fine for all controllers and making it overwriteable was just done
for symmetry.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[Brian: fixed warning]
Tested-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
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