Commit e8e3edb95c ("mtd: create per-device and module-scope debugfs
entries") tried to make MTD related debugfs stuff consistent across the
MTD framework by creating a root <debugfs>/mtd/ directory containing
one directory per MTD device.
The problem is that, by default, the MTD layer only registers the
master device if no partitions are defined for this master. This
behavior breaks all drivers that expect mtd->dbg.dfs_dir to be filled
correctly after calling mtd_device_register() in order to add their own
debugfs entries.
The only way we can force all MTD masters to be registered no matter if
they expose partitions or not is by enabling the
CONFIG_MTD_PARTITIONED_MASTER option.
In such situations, there's no other solution but to accept skipping
debugfs initialization when dbg.dfs_dir is invalid, and when this
happens, inform the user that he should consider enabling
CONFIG_MTD_PARTITIONED_MASTER.
Fixes: e8e3edb95c ("mtd: create per-device and module-scope debugfs entries")
Cc: <stable@vger.kernel.org>
Cc: Mario J. Rugiero <mrugiero@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Several MTD devices are using debugfs entries created in the root.
This commit provides the means for a standardized subtree, creating
one "mtd" entry at root, and one entry per device inside it, named
after the device.
The tree is registered in add_mtd_device, and released in
del_mtd_device.
Devices docg3, mtdswap and nandsim were updated to use this subtree
instead of custom ones, and their entries were prefixed with the
drivers' names.
Signed-off-by: Mario J. Rugiero <mrugiero@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Replace the nand_ecclayout definition by the equivalent mtd_ooblayout_ops
definition.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Use the mtd_set_ecclayout() helper instead of directly assigning the
mtd->ecclayout field.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
ecclayout->oobavail is just redundant with the mtd->oobavail field.
Moreover, it prevents static const definition of ecc layouts since the
NAND framework is calculating this value based on the ecclayout->oobfree
field.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Smatch found a bug in the error handling:
drivers/mtd/devices/docg3.c:1634 doc_register_sysfs()
error: buffer overflow 'doc_sys_attrs' 4 <= 4
The problem is that if the very last device_create_file() fails, then we
are beyond the end of the array. Actually, any time i == 3 then there
is a problem. We can fix this an simplify the code at the same time by
moving the !ret conditions out of the for loops and using a goto
instead.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Fix a bug where mtd parent device symlinks aren't shown in sysfs.
While at it, make use of the default owner value set by mtdcore.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
kasprintf() does a dynamic memory allocation and can fail.
We have to handle that case.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
The .remove callback may be used when detaching a device via sysfs, so
we can't expect to free up this memory.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
If no devices were found, we would already have skipped over this code.
Detected by Coverity, CID #744270
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
* Add device tree support for DoC3
* SPI NOR:
Refactoring, for better layering between spi-nor.c and its driver users
(e.g., m25p80.c)
New flash device support
Support 6-byte ID strings
* NAND
New NAND driver for Allwinner SoC's (sunxi)
GPMI NAND: add support for raw (no ECC) access, for testing purposes
Add ATO manufacturer ID
A few odd driver fixes
* MTD tests:
Allow testers to compensate for OOB bitflips in oobtest
Fix a torturetest regression
* nandsim: Support longer ID byte strings
And more.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQIcBAABAgAGBQJUj6PbAAoJEFySrpd9RFgtahcP/RGvknk9lnitaZI7+aZPP8Zs
AopfiuisLNv3v87EEBAWGYjRYm6vuuhO1z3K55iOIlemBVzoMIP0jf68XGy9uXnL
Ox6AHqxm55wwmc+CHry5/GssaqE6GzdPm8TBP+AGGNhHrhc+raJL55R0QJaoYVwX
pUxkhWaa4lZ6CrOIMQ3n+MEnduilHZoFIcXSc1UtI0y9IXsf1m0Qs8M5jGN8BQ16
HOVNJN9wOXF89swoi7bKsyAn+QFUYgdksAisncb6b9r5Ks5KHmcOuS1LM5X9YoUr
KfeogHfDM68fcaHsSvMU1xmxjXGtE+HFJE52eYNPB1fNbT3JAC13FFj92GeSsZtE
ekpCQh4OPLazT/2wCUHTQwC7T1dCilwyW7VJB9MSl7fSBo9P7jIiUHxVUdM43kez
Di02/XWi4IULTwrgzZiTT8yplFrVdvkmKHAAFEIoaVWiF/l4DeSodLGUw7owmNYn
rJPBPQulpPHRwKZY7gThJuOUXpgbT715GSbvmPYXimHBqmViiPkrhqQ/b/v4PRRs
Nlfhwbswr7WBq6vmPkd6eOyfdFANmWcZQMp/++BCdI/7mhfaik72GWMTBSuJ7hN5
PB+z95soHaKBWlbiDGGGPvuqJmPkOVq1R8itQdIYBWEh7eNSHecwVxyUJJ+V3oPv
QkD7mEP2ZozZe3Ys2EJQ
=gDW8
-----END PGP SIGNATURE-----
Merge tag 'for-linus-20141215' of git://git.infradead.org/linux-mtd
Pull MTD updates from Brian Norris:
"Summary:
- Add device tree support for DoC3
- SPI NOR:
Refactoring, for better layering between spi-nor.c and its
driver users (e.g., m25p80.c)
New flash device support
Support 6-byte ID strings
- NAND:
New NAND driver for Allwinner SoC's (sunxi)
GPMI NAND: add support for raw (no ECC) access, for testing
purposes
Add ATO manufacturer ID
A few odd driver fixes
- MTD tests:
Allow testers to compensate for OOB bitflips in oobtest
Fix a torturetest regression
- nandsim: Support longer ID byte strings
And more"
* tag 'for-linus-20141215' of git://git.infradead.org/linux-mtd: (63 commits)
mtd: tests: abort torturetest on erase errors
mtd: physmap_of: fix potential NULL dereference
mtd: spi-nor: allow NULL as chip name and try to auto detect it
mtd: nand: gpmi: add raw oob access functions
mtd: nand: gpmi: add proper raw access support
mtd: nand: gpmi: add gpmi_copy_bits function
mtd: spi-nor: factor out write_enable() for erase commands
mtd: spi-nor: add support for s25fl128s
mtd: spi-nor: remove the jedec_id/ext_id
mtd: spi-nor: add id/id_len for flash_info{}
mtd: nand: correct the comment of function nand_block_isreserved()
jffs2: Drop bogus if in comment
mtd: atmel_nand: replace memcpy32_toio/memcpy32_fromio with memcpy
mtd: cafe_nand: drop duplicate .write_page implementation
mtd: m25p80: Add support for serial flash Spansion S25FL132K
MTD: m25p80: fix inconsistency in m25p_ids compared to spi_nor_ids
mtd: spi-nor: improve wait-till-ready timeout loop
mtd: delete unnecessary checks before two function calls
mtd: nand: omap: Fix NAND enumeration on 3430 LDP
mtd: nand: add ATO manufacturer info
...
With CONFIG_OF=n, we can see the following warning:
drivers/mtd/devices/docg3.c:2122:28: warning: 'docg3_dt_ids' defined but not used [-Wunused-variable]
static struct of_device_id docg3_dt_ids[] = {
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Add device-tree support. This is straightforward as docg3 only uses the
standard IOMEM resources.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: devicetree@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
seq_printf doesn't return a useful value, so remove
these misuses.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Fixed checkpatch warnings: "WARNING: Prefer seq_puts to seq_printf"
This patch is created with reference to the ongoing lkml thread
https://lkml.org/lkml/2014/7/15/646
where Andrew Morton wrote:
"
- puts is presumably faster
- puts doesn't go rogue if you accidentally pass it a "%".
- this patch would actually make compiled object files few bytes smaller.
Perhaps because seq_printf() is a varargs function, forcing the
caller to pass args on the stack instead of in registers.
"
Signed-off-by: Samarth Parikh <samarthp@ymail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
In line with practice for module parameters, we're adding a build-time
check that sysfs files aren't world-writable.
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Use devm_*() functions to make cleanup paths simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Use free_bch() instead of kfree() to free init_bch()
allocated data.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This patch uses module_platform_driver_probe() macro which makes
the code smaller and simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Be a bit stricter and add few more 'const' qualifiers.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If we set oobdelta to zero then we will either return -EINVAL or hit
a divide (modulus) by zero on the next line when we check
"(ooblen % oobdelta)". It's better to just return -EINVAL here instead.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
There is new format specified that helps to dump small buffers. It makes the
code simpler and nicer.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
- Updates to mxc_nand and gpmi drivers to support new boards and device tree
- Improve consistency of information about ECC strength in NAND devices
- Clean up partition handling of plat_nand
- Support NAND drivers without dedicated access to OOB area
- BCH hardware ECC support for OMAP
- Other fixes and cleanups, and a few new device IDs
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
iEYEABECAAYFAk/JG1wACgkQdwG7hYl686M80wCglN4kutx20j+KJWuZofkr9Hog
weEAoI4jrqEWEdW9EcT2CIWQw7eG+1v+
=7tdo
-----END PGP SIGNATURE-----
Merge tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd
Pull mtd update from David Woodhouse:
- More robust parsing especially of xattr data in JFFS2
- Updates to mxc_nand and gpmi drivers to support new boards and device tree
- Improve consistency of information about ECC strength in NAND devices
- Clean up partition handling of plat_nand
- Support NAND drivers without dedicated access to OOB area
- BCH hardware ECC support for OMAP
- Other fixes and cleanups, and a few new device IDs
Fixed trivial conflict in drivers/mtd/nand/gpmi-nand/gpmi-nand.c due to
added include files next to each other.
* tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd: (75 commits)
mtd: mxc_nand: move ecc strengh setup before nand_scan_tail
mtd: block2mtd: fix recursive call of mtd_writev
mtd: gpmi-nand: define ecc.strength
mtd: of_parts: fix breakage in Kconfig
mtd: nand: fix scan_read_raw_oob
mtd: docg3 fix in-middle of blocks reads
mtd: cfi_cmdset_0002: Slight cleanup of fixup messages
mtd: add fixup for S29NS512P NOR flash.
jffs2: allow to complete xattr integrity check on first GC scan
jffs2: allow to discriminate between recoverable and non-recoverable errors
mtd: nand: omap: add support for hardware BCH ecc
ARM: OMAP3: gpmc: add BCH ecc api and modes
mtd: nand: check the return code of 'read_oob/read_oob_raw'
mtd: nand: remove 'sndcmd' parameter of 'read_oob/read_oob_raw'
mtd: m25p80: Add support for Winbond W25Q80BW
jffs2: get rid of jffs2_sync_super
jffs2: remove unnecessary GC pass on sync
jffs2: remove unnecessary GC pass on umount
jffs2: remove lock_super
mtd: gpmi: add gpmi support for mx6q
...
Corner case reads do not work, and return false data and
ECC. This case is typically seen in a ubifs usage, with a
read of type:
- docg3 docg3: doc_read_oob(from=14882415, mode=1,
data=(c30eca40:12), oob=( (null):0))
This results in the following reads:
- docg3 docg3: doc_read_data_area(buf= (null), len=111)
- docg3 docg3: doc_read_data_area(buf=c30eca40, len=12)
- docg3 docg3: doc_read_data_area(buf= (null), len=389)
- docg3 docg3: doc_read_data_area(buf= (null), len=0)
- docg3 docg3: doc_read_data_area(buf= (null), len=16)
If we suppose that the pages content is :
- bytes 0 .. 111 : 0x0a
- bytes 112 .. 255 : 0x0f
Then the returned bytes will be :
- 111 times 0x0a (correct)
- 0x0a 2 times and 0x0f 10 times (incorrect, should be
0x0a,0x0f)
- 0x0f 389 times (correct)
- nothing
- correct OOB
The reason seams that the first 111 bytes read ends between
the 2 docg3 planes, and that the first following read (in
the 12 bytes sequence, read of 16 bit word) returns the byte
of the rightmost plane duplicated in high and lower byte of
the word.
Fix this behaviour by ensuring that if the previous read
ended up in-between the 2 planes, there will be a first 1
byte read to get back to the beginning of leftmost plane.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
The drivers' _read() method, absent an error, returns a non-negative integer
indicating the maximum number of bit errors that were corrected in any one
region comprising an ecc step. MTD returns -EUCLEAN if this is >=
bitflip_threshold, 0 otherwise. If bitflip_threshold is zero, the comparison is
not made since these devices lack ECC and always return zero in the non-error
case (thanks Brian)¹. Note that this is a subtle change to the driver
interface.
This and the preceding patches in this set were tested with ubi on top of the
nandsim and docg4 devices, running the ubi test io_basic from mtd-utils.
¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040468.html
Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Merge with latest Linus' tree, as I have incoming patches
that fix code that is newer than current HEAD of for-next.
Conflicts:
drivers/net/ethernet/realtek/r8169.c
As docg3 is intolerant against reentrancy, especially
because of its weird register access (ie. a register read is
performed by a first register write), each access to the
docg3 IO space must be locked.
Lock the IO space with a mutex, shared by all chips on the
same cascade, as they all share the same IO space.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Group floors into a common cascade structure. This will provide a common
structure to store common data to all cascaded docg3 chips, like IO
addressing, locking protection.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
After several tries with ubifs, it appears empirically that constructor
provided figures for erase/write timeouts are underestimated. A timeout
of 100ms seems to work with a 5 years worn chip, and no timeouts occur
anymore.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The last erase block was not accessible, as the out of bound
check was incorrectly rejecting the last block.
The read/write/erase offset checks were forbidding the usage of the
last block, because of the calculation which was considering the
byte after the last instead of the last byte.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
doc_probe_device() is only called from docg3_probe() which is in .init.text,
so it must be in the same section to avoid a section mismatch warning.
Signed-off-by: Ryosuke Saito <raitosyo@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Flash device drivers initialize 'ecc_strength' in struct mtd_info, which is the
maximum number of bit errors that can be corrected in one writesize region.
Drivers using the nand interface intitialize 'strength' in struct nand_ecc_ctrl,
which is the maximum number of bit errors that can be corrected in one ecc step.
Nand infrastructure code translates this to 'ecc_strength'.
Also for nand drivers, the nand infrastructure code sets ecc.strength for ecc
modes NAND_ECC_SOFT, NAND_ECC_SOFT_BCH, and NAND_ECC_NONE. It is set in the
driver for all other modes.
Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The read function was so far requiring the reads to be aligned on page
boundaries, and be page length multiples in size. Relieve these
constraints to ease the userspace ubifs programs runs, which read ubifs
headers of 64 bytes.
Artem: squashed a later fix from Robert Jarzmik into this patch.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Change the name of the mtd so that it is simpler, and is easier to
cope with by mtdparts.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The writebufsize concept was introduce by commit
"0e4ca7e mtd: add writebufsize field to mtd_info struct" and it represents
the maximum amount of data the device writes to the media at a time. This is
an important parameter for UBIFS which is used during recovery and which
basically defines how big a corruption caused by a power cut can be.
Set it to be equivalent to mtd->writesize because this is the maximum amount
of data the driver writes at a time.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: stable@kernel.org [3.2+]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch renames all MTD functions by adding a "_" prefix:
mtd->erase -> mtd->_erase
mtd->read_oob -> mtd->_read_oob
...
The reason is that we are re-working the MTD API and from now on it is
an error to use MTD function pointers directly - we have a corresponding
API call for every pointer. By adding a leading "_" we achieve the following:
1. Make sure we convert every direct pointer users
2. A leading "_" suggests that this interface is internal and it becomes
less likely that people will use them directly
3. Make sure all the out-of-tree modules stop compiling and the owners
spot the big API change and amend them.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The 'struct mtd_info' object is allocated with 'kzalloc()', so it
contains only zeroes - no need to initialize various fields to 0 or
NULL.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
As the MTD api has no use for the number of erase cycles
each block has endured, remove the function which calculated
that value.
If one day MTD api finds it usefull for wear levelling
algorithms to have this information, the function should be
put back in place.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch takes into account checkpatch, sparse and ECC
comments.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If doc_probe_device() returned an ERR_PTR, then we accidentally saved
that to docg3_floors[floor] = mtd; which gets derefenced in the error
handling when we call doc_release_device().
I've reworked the error handling to take care of that and hopefully
make it a little simpler.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
As each docg3 chip has 2 protection areas (DPS0 and DPS1),
and because theses areas can prevent user access to the chip
data, add for each floor the sysfs entries which insert the
protection key into the right DPS.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Docg3 chips can work in 3 modes : normal MLC mode, fast
mode and reliable mode. Normally, as docg3 is a MLC chip, it
should be configured to work in normal mode.
In both normal mode, each page is distinct. This
means that writing to page 12 of blocks 14,15 writes only to
that page, and reading from page 12 of blocks 14,15 reads
only from that page.
In reliable and fast modes, pages are coupled by pairs, and
are clones one of each other. This means that the available
capacity of the chip is halved. Pages are coupled in each
block, and page of index 2*n contains the same data as page
2*n+1 of the same block.
In fast mode, the reads occur a bit faster, but are a bit
less reliable that in normal mode.
When reading from page 2*n, the chip reads bytes from both
page 2*n and page 2*n+1, makes a logical and for each byte,
and returns the result. As programming a page means
"clearing bits", even if a bit was not cleared on one page
because the flash is worn out, the other page has the bit
cleared, and the result of the "AND" gives a correct result.
When writing to page 2*n, the chip writes data to both page
2*n and page 2*n+1.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Add functions to powerdown and powerup from suspend, in
order to save power.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Credit for discovering the BCH algorith parameters, and bit
reversing algorithm is to be give to Mike Dunn and Ivan
Djelic.
The BCH correction code relied upon the BCH library, where
all data and ECC is bit-reversed. The BCH library works
correctly when each input byte is bit-reversed, and
accordingly ECC output is also bit-reversed.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Map the developped write and erase functions into the mtd
structure.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Add erase capability to the docg3 driver. The erase block is
made of 2 physical blocks, as both share all 64 pages. That
makes an erase block of at least 64 kBytes.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
