For "unlock" cycles to 16bit devices in 8bit compatibility mode we need
to use the byte addresses 0xaaa and 0x555. These effectively match
the word address 0x555 and 0x2aa, except the latter has its low bit set.

Most chips don't care about the value of the 'A-1' pin in x8 mode,
but some -- like the ST M29W320D -- do. So we need to be careful to
set it where appropriate.

cfi_send_gen_cmd is only ever passed addresses where the low byte
is 0x00, 0x55 or 0xaa. Of those, only addresses ending 0xaa are
affected by this patch, by masking in the extra low bit when the device
is known to be in compatibility mode.

[dwmw2: Do it only when (cmd_ofs & 0xff) == 0xaa]
v4: Fix  stupid typo in cfi_build_cmd_addr that failed to compile
    I'm writing this patch way to late at night.
v3: Bring all of the work back into cfi_build_cmd_addr
    including calling of map_bankwidth(map) and cfi_interleave(cfi)
    So every caller doesn't need to.
v2: Only modified the address if we our device_type is larger than our
    bus width.

Cc: stable@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The CFI information read from AT49BV6416 lists the erase regions in the
wrong order, causing problems when trying to erase or update the first
or last 64KiB block.

Work around this by inverting the "top boot" flag, which will
effectively reverse the order of the erase regions.

This chip is obsolete, but it's used in some existing designs.

Signed-off-by: Håvard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This patch adds TopBottom detection for most Macronix chips with CFI V1.0.

The main purpose of this patch is to add detection of the MX29LV400C B
used on the LaCie Ethernet Disk mini V2 NAS.

It detects the following parts correctly:-
MX28F640C3B T
MX29LV002C  B
MX29LV002NC B
MX29LV004C  T
MX29LV400C  T/B
MX29LV800C  T/B
MX29LV160C  T/B
MX29SL800C  T/B
MX29SL802C  T/B

It detects the following uniform part as bottom but it should work
correctly:-
MX29LV040C

For T parts it causes the erase block table to be reversed correctly.
For other parts it avoids the bogus "Assuming top" message.

It does not detect the following correctly:-
MX28F640C3B B
MX29LV002C  T
MX29LV002NC T
MX29LV004C  B
MX29SL400C  T/B
MX29SL402C  T/B

If desired I could supply a more complicated patch to handle these as
well.

Only the MX29LV400C B has been physically tested; others were checked
against their data sheets.

Signed-off-by: Christopher Moore <moore@free.fr>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The patch fixes CFI issue with multipartitional devices leading to the 
set of errors or even deadlock. The problem is CFI FL_SYNCING state race 
with flash operations (e.g. erase suspend). It is reproduced by running 
intensive writes on one JFFS2 partition and simultaneously performing 
mount/unmount cycle on another partition of the same chip.

Signed-off-by: Alexander Belyakov <abelyako@googlemail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

It requires cfi_qry_mode_on(), which is in cfi_util.c

Reported by Russell King

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

They need to be exported, so let's give them less generic-sounding names
while we're at it.

Original export patch, along with the suggestion about the nomenclature,
from Stephen Rothwell.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Timeouts are currently given by the typical operation time times 8.
It works in the general well-behaved case but not when an erase block is
failing. For erase operations, it seems that a failing erase block will
keep the device state machine in erasing state until the vendor
specified maximum timeout period has passed. By this time the driver
would have long since timed out, left erasing state and attempted
further operations which all fail. This patch implements timeouts using
values from the CFI Query structure when available.
The patch also sets a longer timeout for locking operations. The current
value used for locking/unlocking given by 1000000/HZ microseconds is too
short for devices like J3 and J5 Strataflash which have a typical clear
lock-bits time of 0.5 seconds.

Signed-off-by: Anders Grafström <grfstrm@users.sourceforge.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

There are some CFI chips which require non standard procedures to get 
into QRY mode. The possible way to support them would be trying 
different modes till QRY will be read. This patch introduce two new 
functions qry_mode_on qry_mode_off. qry_mode_on tries different commands 
in order switch chip into QRY mode.

So if we have one more "odd" chip - we just could add several lines to 
qry_mode_on. Also using these functions remove unnecessary code 
duplicaton in porbe procedure.

Currently there are two "odd" cases
1. Some old intel chips which require 0xFF before 0x98
2. ST M29DW chip which requires 0x98 to be sent at 0x555 (according to
CFI should be 0x55)

This patch is partialy based on the patch from Uwe
(see "[PATCH 2/4] [RFC][MTD] cfi_probe: remove Intel chip workaround"
thread )

Signed-off-by: Alexey Korolev <akorolev@infradead.org>
Signed-off-by: Alexander Belyakov <abelyako@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

This long overdue trivial change to the MTD_CFI_AMDSTD kconfig menu
description is intended to help clarify that this option also supports
Spansion flash devices.

Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
(d)) but is perhaps more readable.

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>