Commit Graph

108 Commits

Author SHA1 Message Date
Randy Dunlap
d3af0f048c [MTD] [NAND] remove excess kernel-doc notation
Delete extra kernel-doc notation for struct fields and function
parameters that don't exist:

Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'wq' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'datbuf' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'oobbuf' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'oobdirty' description in 'nand_chip'
Warning(include/linux/mtd/nand.h:428): Excess struct/union/enum/typedef member 'data_poi' description in 'nand_chip'
Warning(drivers/mtd/nand/nand_base.c:2527): Excess function parameter 'maxchips' description in 'nand_scan_tail'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-12-10 16:10:40 +00:00
Adrian Hunter
69423d99fc [MTD] update internal API to support 64-bit device size
MTD internal API presently uses 32-bit values to represent
device size.  This patch updates them to 64-bits but leaves
the external API unchanged.  Extending the external API
is a separate issue for several reasons.  First, no one
needs it at the moment.  Secondly, whether the implementation
is done with IOCTLs, sysfs or both is still debated.  Thirdly
external API changes require the internal API to be accepted
first.

Note that although the MTD API will be able to support 64-bit
device sizes, existing drivers do not and are not required
to do so, although NAND base has been updated.

In general, changing from 32-bit to 64-bit values cause little
or no changes to the majority of the code with the following
exceptions:
    	- printk message formats
    	- division and modulus of 64-bit values
    	- NAND base support
	- 32-bit local variables used by mtdpart and mtdconcat
	- naughtily assuming one structure maps to another
	in MEMERASE ioctl

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-12-10 13:37:21 +00:00
Karl Beldan
ef89a88013 [MTD] [NAND] nand_base.c: reset chip first
Some chips require a RESET after power-up (e.g. Micron MT29FxGxxxxx).
The first command sent is NAND_CMD_READID.
Issue a NAND_CMD_RESET in nand_scan_ident before reading the device id.
Tested with an MT29F4G08AAC.

Signed-off-by: Karl Beldan <karl.beldan@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-09-16 08:18:12 -07:00
Alexey Korolev
17c1d2be28 [MTD] [NAND] Fix missing kernel-doc
[Reported by Randy Dunlap]

Signed-off-by: Alexey Korolev <akorolev@infradead.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-08-20 22:35:40 +01:00
Adrian Hunter
bb0eb217c9 [MTD] Define and use MTD_FAIL_ADDR_UNKNOWN instead of 0xffffffff
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-08-12 11:02:15 +01:00
Alexey Korolev
3d45955962 [MTD] [NAND] subpage read feature as a way to increase performance.
This patch enables NAND subpage read functionality.
If upper layer drivers are requesting to read non page aligned data NAND
subpage-read functionality reads the only whose ECC regions which include
requested data when original code reads whole page.
This significantly improves performance in many cases.

Here are some digits :

UBI volume mount time
No subpage reads: 5.75 seconds
Subpage read patch: 2.42 seconds

Open/stat time for files on JFFS2 volume:
No subpage read  0m 5.36s
Subpage read     0m 2.88s

Signed-off-by Alexey Korolev <akorolev@infradead.org>
Acked-by: Artem Bityutskiy <dedekind@infradead.org>
Acked-by: Jörn Engel <joern@logfs.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-07-25 10:49:50 -04:00
Ben Dooks
ed8165c75e [MTD] [NAND] Verify probe by retrying to checking the results match
With modern systems using bus-hold instead of bus pull-up, it can
often lead to erroneous reporting of NAND devices where there are
none. Do a double probe to ensure that the result we got the first
time is repeatable, and if it is not then return that there is no
chip there.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2008-04-22 21:43:06 +01:00
Linus Torvalds
a8e98d6d51 Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6: (120 commits)
  [MTD] Fix mtdoops.c compilation
  [MTD] [NOR] fix startup lock when using multiple nor flash chips
  [MTD] [DOC200x] eccbuf is statically defined and always evaluate to true
  [MTD] Fix maps/physmap.c compilation with CONFIG_PM
  [MTD] onenand: Add panic_write function to the onenand driver
  [MTD] mtdoops: Use the panic_write function when present
  [MTD] Add mtd panic_write function pointer
  [MTD] [NAND] Freescale enhanced Local Bus Controller FCM NAND support.
  [MTD] physmap.c: Add support for multiple resources
  [MTD] [NAND] Fix misparenthesization introduced by commit 78b65179...
  [MTD] [NAND] Fix Blackfin NFC ECC calculating bug with page size 512 bytes
  [MTD] [NAND] Remove wrong operation in PM function of the BF54x NFC driver
  [MTD] [NAND] Remove unused variable in plat_nand_remove
  [MTD] Unlocking all Intel flash that is locked on power up.
  [MTD] [NAND] at91_nand: Make mtdparts option can override board info
  [MTD] mtdoops: Various minor cleanups
  [MTD] mtdoops: Ensure sequential write to the buffer
  [MTD] mtdoops: Perform write operations in a workqueue
  [MTD] mtdoops: Add further error return code checking
  [MTD] [NOR] Test devtype, not definition in flash_probe(), drivers/mtd/devices/lart.c
  ...
2008-02-07 10:20:31 -08:00
Joe Perches
8e87d7820a drivers/mtd/: Spelling fixes
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2008-02-03 17:22:34 +02:00
Scott Wood
1c45f60406 [MTD] [NAND] Fix misparenthesization introduced by commit 78b65179...
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2008-02-03 22:14:12 +11:00
Scott Wood
78b65179d0 [MTD] [NAND] Don't panic if a controller driver does ecc its own way.
Some hardware, such as the enhanced local bus controller used on some
mpc83xx chips, does ecc transparently when reading and writing data, rather
than providing a generic calculate/correct mechanism that can be exported to
the nand subsystem.

The subsystem should not BUG() when calculate, correct, or hwctl are
missing, if the methods that call them have been overridden.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2008-01-08 07:51:57 +00:00
Matt Reimer
c32b8dcc45 [MTD] [NAND] treat any negative return value from correct() as an error
Treat any negative return value from a NAND driver's correct() function
as a failure, rather than just -1.

Signed-off-by: Matt Reimer <mreimer@vpop.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-10-20 22:27:22 +01:00
David Woodhouse
49defc015f [MTD] [NAND] Avoid deadlock in erase callback; release chip lock first.
When the erase callback performs some other action on the flash, it's
highly likely to deadlock unless we actually release the chip lock
before calling it.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-10-06 15:01:59 -04:00
maximilian attems
8b2b403ce0 [MTD] [NAND] nand_base.c fix broken link
replace with working link from nand Kconfig help text
fixes bugzilla 7815

Signed-off-by: maximilian attems <max@stro.at>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-08-01 11:12:21 +01:00
Artem Bityutskiy
c0b8ba7bfe [MTD] [NAND] fix race in nand_base.c
When we mark block bad we have to get chip because this involves
writing to the page's OOB. We hit this bug in UBI - we observed
random obscure crashes when it marks block bad from the background
thread and there is some parallel task which utilizes flash.

This patch also adds a TODO note about BBT table protection which
it seems does not exist.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-07-23 13:09:52 +01:00
Ben Dooks
8b099a390d [MTD] [NAND] nand_base.c: fix type of eccpos pointer
The nand_base.c driver implicitly casts the uint32_t
eccpos array to 'int *', which is not only not guaranteed
to be the same sign as the source, but is not guaranteed
to be the same size.

Fix by changing nand_base.c to use uint32_t
referencing the eccpos fields.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-06-28 20:23:40 +01:00
Thomas Knobloch
1a12f46af1 [MTD] [NAND] Tidy up handling of page number in nand_block_bad()
Further to the previous patch fixing the calculation of page number,
both branches are using the same result. Clean up the function 
accordingly, calculating it (and also masking with pagemask) only in one 
place.

Signed-off-by: Thomas Knobloch <knobloch@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-05-03 07:39:37 +01:00
Knobloch, Thomas
78ab67da10 [MTD] [NAND] Wrong calculation of page number in nand_block_bad()
In case that there is no memory based bad block table available the
function nand_block_checkbad() in drivers/mtd/nand/nand_base.c will call
nand_block_bad() directly. When parameter 'getchip' is set to zero,
nand_block_bad() will not right shift the offset to calculate the
correct page number.

Signed-off-by: Thomas Knobloch <knobloch@siemens.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-04-27 15:13:53 +01:00
Andre Renaud
4226b51037 [MTD] [NAND] Casting bug in nand_default_block_markbad
There is a slight bug in nand_default_block_markbad, where the offset is
cast to an integer, prior to being shifted. This means that on large
offsets, it is incorrectly doing a signed shift & losing bits. Fixed
this by doing the cast after the shift (as is done elsewhere in the code).

Signed-off-by: Andre Renaud <andre@bluewatersys.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-04-17 13:50:59 -04:00
Thomas Gleixner
90424de8d0 [MTD] [NAND] Use ecc.read/write_page_raw consequently
Use the functions in the ecc structure instead of the default ones,
so the override by the board driver is effective also for software ecc
code paths.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-04-17 18:28:17 +01:00
Vitaly Wool
1f92267c51 [MTD] [NAND] make oobavail public
During the MTD rework the oobavail parameter of mtd_info structure has become
private. This is not quite correct in terms of integrity and logic. If we have
means to write to OOB area, then we'd like to know upfront how many bytes out
of OOB are spare per page to be able to adapt to specific cases.
The patch inlined adds the public oobavail parameter.

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-03-08 09:17:43 +00:00
Artem Bityutskiy
64f6071056 [MTD] remove unused ecctype,eccsize fields from struct mtd_info
Remove unused and broken mtd->ecctype and mtd->eccsize fields
from struct mtd_info. Do not remove them from userspace API
data structures (don't want to breake userspace) but mark them
as obsolete by a comment. Any userspace program which uses them
should be half-broken anyway, so this is more about saving
data structure size.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-02-09 15:27:12 +00:00
Adrian Hunter
0373615579 [MTD] [NAND] Correctly validate out-of-band offset and length
Add checks to ensure that out-of-band reads and writes are
not attempted with an invalid offset or length.  Specifically,
the offset must be less than the size of oob for a page
and the length must not go beyond the size of the device.
Additionally the checks must adjust for auto-placement
(MTD_OOB_AUTO) of oob data.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2007-02-09 15:02:40 +00:00
David Woodhouse
bd3c97a7c7 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2006-12-01 09:56:43 +00:00
Thomas Gleixner
29072b9607 [MTD] NAND: add subpage write support
Many SLC NANDs support up to 4 writes at one NAND page. Add support
of this feature.

Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
2006-11-29 17:03:52 +02:00
Vitaly Wool
7014568bad [MTD] [NAND] remove len/ooblen confusion.
As was discussed between Ricard Wanderlöf, David Woodhouse, Artem 
Bityutskiy and me, the current API for reading/writing OOB is confusing. 

The thing that introduces confusion is the need to specify ops.len 
together with ops.ooblen for reads/writes that concern only OOB not data 
area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to 
specify the length of the data read, and when ops.datbuf == NULL, it 
serves to specify the full OOB read length.

The patch inlined below is the slightly updated version of the previous 
patch serving the same purpose, but with the new Artem's comments taken 
into account.

Artem, BTW, thanks a lot for your valuable input!

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-11-28 22:39:03 +00:00
Jesper Juhl
efbfe96c5d [PATCH] silence 'make xmldocs' warning by adding missing description of 'raw' in nand_base.c:1485
Add description of 'raw' in comments for
drivers/mtd/nand/nand_base.c::nand_write_page_syndrome() so 'make xmldocs'
will not spew a warning at us.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-27 15:34:51 -07:00
Ricard Wanderlöf
ff0dab64b4 [MTD] NAND: Fix nand_default_mark_blockbad() when flash-based BBT disabled
When a flash-based BBT is not used, nand_default_mark_blockbad() is supposed
to mark the block bad in the oob. However, it sets the wrong length variable
so that no bad block marker is in fact written. This patch attempts to
rectify that.

(As note, it seems to be that logically, it shouldn't be necessary to set
both length variables, as one appears to be for the main buffer, and
one for the oob buffer, but this is how it is done in several places,
including the code for the mtd character device MEMWRITEOOB and MEMREADOOB
ioctls. I'm not sure if this is a temporary solution during some rework of
the mtd infrastructure, or whether there is a deeper thought here.)

Signed-off-by: Ricard Wanderlöf <ricardw@axis.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-26 13:17:49 +03:00
David Woodhouse
784f4d5e66 [MTD] NAND: Correct setting of chip->oob_poi OOB buffer
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-22 01:47:45 +01:00
David Woodhouse
7dcdcbef5d [MTD] NAND: Combined oob buffer so it's contiguous with data
Ditch the separate oobrbuf and oobwbuf fields from the chip buffers,
and use only a single buffer immediately after the data. This accommodates
NAND controllers such as the OLPC CAFÉ chip, which can't do scatter/gather
DMA so needs the OOB buffer to be contiguous with the data, for both read
and write.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-21 17:48:58 +01:00
Artem Bityutskiy
d29ebdbee4 [MTD] core: trivial comments fix
Signed-off-by: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-10-21 16:42:53 +01:00
David Woodhouse
956e944c76 [MTD NAND] Allow override of page read and write functions.
- allow high-level nand_write_page() function to be overridden
- likewise low-level write_page_raw() and read_page_raw() functions
- Clean up the abuse of chip->ecc.{write,read}_page() with MTD_OOB_RAW

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:12:39 +01:00
David Woodhouse
4bf63fcb83 [MTD NAND] Allocate chip->buffers separately to allow it to be overridden
In particular, the board driver might need it to be DMAable.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:08:04 +01:00
David Woodhouse
3b85c3211e [MTD NAND] Split nand_scan() into two parts; allow board driver to intervene
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:06:53 +01:00
David Woodhouse
4b648b0253 [MTD NAND] Export nand_wait_ready() for use by board drivers
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-09-25 17:05:24 +01:00
David Woodhouse
0a7d5f8ce9 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2006-08-30 23:30:38 +01:00
Richard Purdie
7fd5aecc5d [PATCH] mtd corruption fix
Read the return value before we release the nand device otherwise the
value can become corrupted by another user of chip->ops, ultimately
resulting in filesystem corruption.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:29 -07:00
David Woodhouse
9a909867d2 [MTD NAND] Fix lookup error in nand_get_flash_type()
Spotted by liyu <liyu@ccoss.com.cn>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-07-15 13:26:18 +01:00
Vitaly Wool
8b0036eefd [MTD] NAND: OOB buffer offset fixups
In the case of data-pad-ecc-pad-data... layout the oob start position
has to be sizeof(data) in nand_write_oob_syndrom().

In nand_fill_oob() we need to copy to buf + buffer offset instead of
buf + write offset.

From: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-07-11 09:11:25 +02:00
Randy Dunlap
844d3b427e MTD: fix all kernel-doc warnings
Fix all kernel-doc warnings in MTD headers and source files:
- add some missing struct fields;
- correct some function parameter names;
- use kernel-doc format for function doc. headers;
- nand_ecc.c contains only exported interfaces, no internal ones;

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-06-29 08:55:00 +01:00
Thomas Gleixner
6a93096195 [MTD] NAND: Select chip before checking write protect status
The other way round works not really well with boards which have a
static NAND chipselect.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-06-27 23:24:09 +01:00
Savin Zlobec
0d420f9d61 [MTD] NAND: Missing fixups
The oob fixups broke a return value and missed one patch from
the Mailing List.

Signed-off-by: Savin Zlobec <savin@epico.si>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-06-21 13:11:56 +01:00
Thomas Gleixner
7bc3312bef [MTD] NAND: Fix breakage all over the place
Following problems are addressed:

- wrong status caused early break out of nand_wait()
- removed the bogus status check in nand_wait() which
  is a relict of the abandoned support for interrupted
  erase.
- status check moved to the correct place in read_oob
- oob support for syndrom based ecc with strange layouts
- use given offset in the AUTOOOB based oob operations

Partially based on a patch from Vitaly Vool <vwool@ru.mvista.com>
Thanks to Savin Zlobec <savin@epico.si> for tracking down the
status problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-06-20 20:31:24 +01:00
Vitaly Wool
7e4178f90e [PATCH] NAND: fix remaining OOB length calculation
In nand_read_page_syndrome/nand_write_page_syndrome the calculation of
the remaining oob length which is not used by the prepad/ecc/postpad
areas is wrong.

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-06-20 20:31:23 +01:00
Andrew Morton
7e9a0bb00c [MTD] Fix build warnings (and debug build error) in nand_base.c
drivers/mtd/nand/nand_base.c: In function 'nand_transfer_oob':
drivers/mtd/nand/nand_base.c:909: warning: comparison of distinct pointer types lacks a cast
drivers/mtd/nand/nand_base.c: In function 'nand_do_read_oob':
drivers/mtd/nand/nand_base.c:1097: error: 'len' undeclared (first use in this function)
drivers/mtd/nand/nand_base.c:1097: error: (Each undeclared identifier is reported only once
drivers/mtd/nand/nand_base.c:1097: error: for each function it appears in.)
drivers/mtd/nand/nand_base.c: In function 'nand_fill_oob':
drivers/mtd/nand/nand_base.c:1411: warning: comparison of distinct pointer types lacks a cast

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-30 09:06:41 +01:00
Thomas Gleixner
f1a28c0284 [MTD] NAND Expose the new raw mode function and status info to userspace
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: Thomas Gleixner <tglx@linutronix.de>
2006-05-30 00:37:34 +02:00
Thomas Gleixner
9a1fcdfd4b [MTD] NAND Signal that a bitflip was corrected by ECC
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: Thomas Gleixner <tglx@linutronix.de>
2006-05-29 15:06:51 +02:00
Thomas Gleixner
8593fbc68b [MTD] Rework the out of band handling completely
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: Thomas Gleixner <tglx@linutronix.de>
2006-05-29 15:06:51 +02:00
Thomas Gleixner
5bd34c091a [MTD] NAND Replace oobinfo by ecclayout
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: Thomas Gleixner <tglx@linutronix.de>
2006-05-29 15:06:50 +02:00
Thomas Gleixner
ff268fb879 [MTD] NAND Consolidate oobinfo handling
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: Thomas Gleixner <tglx@linutronix.de>
2006-05-29 15:06:49 +02:00