The raw read/write access to NAND (without ECC) has been changed in the
NAND rework. Expose the new way - setting the file mode via ioctl - to
userspace. Also allow to read out the ecc statistics information so userspace
tools can see that bitflips happened and whether errors where correctable
or not. Also expose the number of bad blocks for the partition, so nandwrite
can check if the data fits into the parition before writing to it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Return -EUCLEAN on read when a bitflip was detected and corrected, so the
clients can react and eventually copy the affected block to a spare one.
Make all in kernel users aware of the change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Hopefully the last iteration on this!

The handling of out of band data on NAND was accompanied by tons of fruitless
discussions and halfarsed patches to make it work for a particular
problem. Sufficiently annoyed by I all those "I know it better" mails and the
resonable amount of discarded "it solves my problem" patches, I finally decided
to go for the big rework. After removing the _ecc variants of mtd read/write
functions the solution to satisfy the various requirements was to refactor the
read/write _oob functions in mtd.

The major change is that read/write_oob now takes a pointer to an operation
descriptor structure "struct mtd_oob_ops".instead of having a function with at
least seven arguments.

read/write_oob which should probably renamed to a more descriptive name, can do
the following tasks:

- read/write out of band data
- read/write data content and out of band data
- read/write raw data content and out of band data (ecc disabled)

struct mtd_oob_ops has a mode field, which determines the oob handling mode.

Aside of the MTD_OOB_RAW mode, which is intended to be especially for
diagnostic purposes and some internal functions e.g. bad block table creation,
the other two modes are for mtd clients:

MTD_OOB_PLACE puts/gets the given oob data exactly to/from the place which is
described by the ooboffs and ooblen fields of the mtd_oob_ops strcuture. It's
up to the caller to make sure that the byte positions are not used by the ECC
placement algorithms.

MTD_OOB_AUTO puts/gets the given oob data automaticaly to/from the places in
the out of band area which are described by the oobfree tuples in the ecclayout
data structre which is associated to the devicee.

The decision whether data plus oob or oob only handling is done depends on the
setting of the datbuf member of the data structure. When datbuf == NULL then
the internal read/write_oob functions are selected, otherwise the read/write
data routines are invoked.

Tested on a few platforms with all variants. Please be aware of possible
regressions for your particular device / application scenario

Disclaimer: Any whining will be ignored from those who just contributed "hot
air blurb" and never sat down to tackle the underlying problem of the mess in
the NAND driver grown over time and the big chunk of work to fix up the
existing users. The problem was not the holiness of the existing MTD
interfaces. The problems was the lack of time to go for the big overhaul. It's
easy to add more mess to the existing one, but it takes alot of effort to go
for a real solution.

Improvements and bugfixes are welcome!
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The nand_oobinfo structure is not fitting the newer error correction
demands anymore. Replace it by struct nand_ecclayout and fixup the users
all over the place. Keep the nand_oobinfo based ioctl for user space
compability reasons.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The info structure for out of band data was copied into
the mtd structure. Make it a pointer and remove the ability
to set it from userspace. The position of ecc bytes is
defined by the hardware and should not be changed by software.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We have a type pointer. Make use of it instead of the error prone nand_ids[i]
reference.

The NAND driver used to set default name settings from the chip ID
string for the device. The feature got lost during the rework. Add it back.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

nCE setting can be done when the first command is issued to the device.
We keep the deselect functionality as it makes sense to deassert nCE
when the device becomes idle.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Modularize the write function and reorganaize the internal buffer
management. Remove obsolete chip options and fixup all affected
users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Bad tglx. No biscuit.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Split the core of the read function out and implement
seperate handling functions for software and hardware
ECC.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Cleanup the code in the oob related functions and
make use of the new NO_READRDY flag.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The lock simplifying patch did not move the lock and waitqueue
initialization into the controller allocation patch.
This reinitializes waitqueue and spinlocks also for driver
supplied controller stuctures. Move it into the allocation path.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The cmd_ctrl rework lacks some state transition flags.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Cleanup the functions which are not going to change in the
next steps.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Move the define out of the middle of the code and add an
appropriate comment.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The previous change of the command / hardware control allows to
remove the write_byte/word functions completely, as their only
user were nand_command and nand_command_lp.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The hwcontrol function enforced a step by step state machine
for any kind of hardware chip access. Let the hardware driver
know which control bits are set and inform it about a change
of the control lines. Let the hardware driver write out the
command and address bytes directly. This gives a peformance
advantage for address bus controlled chips and simplifies the
quirks in the hardware drivers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The previous _ecc removal / cleanup broke (i)nftl module usage.
Export the missing symbol.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

MTD clients are agnostic of FLASH which needs ECC suppport.
Remove the functions and fixup the callers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

These functions were never implemented and added only bloat to
partition and concat code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

NAND writev(_ecc) support is not longer necessary. Remove it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

First step of modularizing ECC support.
- Move ECC related functionality into a seperate embedded data structure
- Get rid of the hardware dependend constants to simplify new ECC models
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Seperate functionality out of nand_scan so the code is more
readable. No functional change. First step of simplifying
the nand driver.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The NAND driver used a mix of unsigned char, u_char amd uint8_t
data types. Consolidate to uint8_t usage
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Replace the chip lock by a the controller lock. For simple drivers a
dummy controller structure is created by the scan code.
This simplifies the locking algorithm in nand_get/release_chip().
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

o Add a flag MTD_BIT_WRITEABLE for devices that allow single bits to be
  cleared.
o Replace MTD_PROGRAM_REGIONS with a cleared MTD_BIT_WRITEABLE flag for
  STMicro and Intel Sibley flashes with internal ECC.  Those flashes
  disallow clearing of single bits, unlike regular NOR flashes, so the
  new flag models their behaviour better.
o Remove MTD_ECC.  After the STMicro/Sibley merge, this flag is only set
  and never checked.
Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>

At least two flashes exists that have the concept of a minimum write unit,
similar to NAND pages, but no other NAND characteristics.  Therefore, rename
the minimum write unit to "writesize" for all flashes, including NAND.
Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>

Make it work even with compilers which lack the wit to notice that
THIS_MODULE is always non-NULL. Use #ifdef MODULE instead. It's only
a temporary debugging check anyway.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

The _board_ driver needs to be mtd->owner, and it in turn pins the
nand.ko module. Fix them all to actually do that, and fix nand.ko not to
overwrite it -- and also to check that the caller sets it, if the caller
is a module.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

It was just too painful to deal with.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is the drivers/mtd part of the big kfree cleanup patch.

Remove pointless checks for NULL prior to calling kfree() in drivers/mtd/.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: NJoern Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Nathan Roberts noticed the nand_write_ecc index into oobbuf goes out of
bounds when crossing an erase block boundary, causing incorrect OOB data
to be written and corrupting memory.  Reset the index to zero after
re-preparing oobbuf for a new erase block.
Signed-off-by: NTodd Poynor <tpoynor@mvista.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

In case of an odd offset, the result was shifted by 1 instead of 8
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The changes introduced allow to suspend/resume NAND flash.
A new state (FL_PM_SUSPENDED) is introduced, as well as
routines for mtd->suspend and mtd->resume to put the flash in
suspended state from software pov.
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The bit mask used for oob size calculation was using 2 bits instead
of one. Fortunately the next bit has been 0 all the time.

Thanks to Nathan H. for pointing this out
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP.

When enabled then per-CPU watchdog threads are started, which try to run
once per second.  If they get delayed for more than 10 seconds then a
callback from the timer interrupt detects this condition and prints out a
warning message and a stack dump (once per lockup incident).  The feature
is otherwise non-intrusive, it doesnt try to unlock the box in any way, it
only gets the debug info out, automatically, and on all CPUs affected by
the lockup.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-Off-By: NMatthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>