Commit Graph

182 Commits

Author SHA1 Message Date
Boris BREZILLON 6e9411923b mtd: nand: return consistent error codes in ecc.correct() implementations
The error code returned by the ecc.correct() are not consistent over the
all implementations.

Document the expected behavior in include/linux/mtd/nand.h and fix
offending implementations.

[Brian: this looks like a bugfix for the ECC reporting in the bf5xx_nand
driver, but we haven't seen any testing results for it]

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Franklin S Cooper Jr. <fcooper@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2016-01-06 18:45:46 -08:00
Boris BREZILLON 8142b47ef3 mtd: nand: remove unused and buggy get_platform_nandchip() helper function
Nobody uses the get_platform_nandchip() helper function which is supposed
to return a pointer to a platform_nand_chip struct from an mtd_info
pointer.
Moreover, this function is buggy since the introduction of the plat_nand
layer (chip->priv is now storing a pointer to an intermediate
plat_nand_data structure allocated in plat_nand_probe(), and we have no
way to retrieve a pointer to the provided platform_nand_chip struct from
this plat_nand_data pointer).

While we are at it, remove the useless (and buggy, since it's pointing to
something stored on the stack) data->chip.priv assignment.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: 711fdf627c ("[MTD] [NAND] platform NAND driver: add driver")
Cc: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-12-18 14:24:36 -08:00
Boris BREZILLON 29574ede09 mtd: nand: kill the chip->flash_node field
Now that the nand_chip struct directly embeds an mtd_info struct we can
get rid of the ->flash_node field and forward set/get_flash_node requests
to the MTD layer.

As a side effect, we no longer need the mtd_set_of_node() call done in
nand_dt_init().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-12-18 13:22:53 -08:00
Boris BREZILLON 2d3b77bac3 mtd: nand: update mtd_to_nand()
Now that all drivers are using the mtd instance embedded in the nand_chip
struct we can safely update the mtd_to_nand() implementation to use
the container_of macro instead of returning the content of mtd->priv.
This will allow us to remove mtd->priv = chip assignments done in all
NAND controller drivers.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-12-18 13:19:10 -08:00
Boris BREZILLON ffd014f43f mtd: nand: add nand_to_mtd() helper
Add a new helper to retrieve the MTD device attached to a NAND chip.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-12-08 12:25:20 -08:00
Boris BREZILLON ed4f85c03c mtd: nand: embed an mtd_info structure into nand_chip
Currently all NAND controller drivers are providing both the mtd_info and
nand_chip struct and then let the NAND subsystem to initialize a few
things before registering the mtd instance to the MTD layer.
Embed an mtd_info field into nand_chip to add some consistency to all NAND
controller drivers.
This change will also help factorizing boilerplate code copied in all NAND
drivers.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-12-08 12:25:20 -08:00
Brian Norris 74e98be45f mtd: nand: fix typo (t_ald -> t_adl)
It's "ADL" ("ALE to data loading" time) not "ALD".

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
2015-12-01 11:17:18 -08:00
Boris BREZILLON de64aa9ec1 mtd: nand: fix ONFI parameter page layout
src_ssync_features field is only 1 byte large, and the 4th reserved area
is actually 8 bytes large.

Fixes: d1e1f4e42b ("mtd: nand: add support for reading ONFI parameters from NAND device")
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-12-01 11:03:42 -08:00
Brian Norris c291b3c352 mtd: merge in mtd_to_nand() branch
In case other subsystems want to merge in this helper for use in their
drivers, let's bring in that development separately from the rest of
MTD -next development.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-11-19 11:12:28 -08:00
Boris BREZILLON 9eba47ddd8 mtd: nand: add an mtd_to_nand() helper
Some drivers are retrieving the nand_chip pointer using the container_of
macro on a struct wrapping both the nand_chip and the mtd_info struct while
the standard way of retrieving this pointer is through mtd->priv.
Provide an helper to do that.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-11-19 11:09:10 -08:00
Brian Norris 28b8b26b30 mtd: add get/set of_node/flash_node helpers
We are going to begin using the mtd->dev.of_node field for MTD device
nodes, so let's add helpers for it. Also, we'll be making some
conversions on spi_nor (and nand_chip eventually) too, so get that ready
with their own helpers.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
2015-11-11 13:45:05 -08:00
Boris BREZILLON 45aaeff947 mtd: nand: pass page number to ecc->write_xxx() methods
The ->read_xxx() methods are all passed the page number the NAND controller
is supposed to read, but ->write_xxx() do not have such a parameter.

This is a problem if we want to properly implement data
scrambling/randomization in order to mitigate MLC sensibility to repeated
pattern: to prevent bitflips in adjacent pages in the same block we need
to avoid repeating the same pattern at the same offset in those pages,
hence the randomizer/scrambler engine need to be passed the page value
in order to adapt its seed accordingly.

Moreover, adding the page parameter to the ->write_xxx() methods add some
consistency to the current API.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
CC: Josh Wu <josh.wu@atmel.com>
CC: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Huang Shijie <shijie.huang@arm.com>
CC: Stefan Agner <stefan@agner.ch>
CC: devel@driverdev.osuosl.org
CC: linux-arm-kernel@lists.infradead.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-10-13 12:56:49 -07:00
Boris BREZILLON a7f5ba40c7 mtd: nand: remove unused ->init_size() hook
The ->init_size() hook was introduced to let NAND controller drivers
support NAND devices that could not be described in the nand_ids table.
Since then, the core has added support for extended-id parsing and
full-id description, thus allowing to describe pretty much all existing
NANDs.
Moreover, this hook is not used by any mainline driver, and should not be
used by new drivers, because detecting the NAND chip is not something
controller specific.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-10-01 10:20:15 -07:00
Boris BREZILLON 730a43fbc1 mtd: nand: add nand_check_erased helper functions
Add two helper functions to help NAND controller drivers test whether a
specific NAND region is erased or not.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-09-21 15:35:04 -07:00
Marek Vasut 61528d888a mtd: nand: Rename nand_chip .dn to .flash_node
Use a more descriptive name for the device_node element in struct nand_chip .
This name matches the element name used for device_node property of a flash
in the spi-nor framework.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-09-11 15:48:43 -07:00
Scott Wood 5f867db634 mtd: nand: Fix NAND_USE_BOUNCE_BUFFER flag conflict
Commit 66507c7bc8 ("mtd: nand: Add support to use nand_base
poi databuf as bounce buffer") added a flag NAND_USE_BOUNCE_BUFFER
using the same bit value as the existing NAND_BUSWIDTH_AUTO.

Cc: Kamal Dasu <kdasu.kdev@gmail.com>
Fixes: 66507c7bc8 ("mtd: nand: Add support to use nand_base
	poi databuf as bounce buffer")
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-07-07 13:03:25 -07:00
Brian Norris 5844feeaa4 mtd: nand: add common DT init code
These are already-documented common bindings for NAND chips. Let's
handle them in nand_base.

If NAND controller drivers need to act on this data before bringing up
the NAND chip (e.g., fill out ECC callback functions, change HW modes,
etc.), then they can do so between calling nand_scan_ident() and
nand_scan_tail().

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-05-11 16:22:29 -07:00
Brian Norris 17799359e7 mtd: nand_bbt: make nand_scan_bbt() static
This implementation detail is no longer needed outside of nand_bbt.c.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2015-05-06 20:02:35 -07:00
Brian Norris 641519cb61 mtd: nand: add ATO manufacturer info
Tested with ATO AFND1G08U3, 128MiB NAND.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-11-25 20:11:12 -08:00
Boris BREZILLON 62d956dc3e mtd: nand: provide detailed description for raw read/write page methods
read_page_raw and write_page_raw method description is not clear enough.
It clearly specifies that ECC correction should not be involved but does
not talk about specific layout (by layout I mean where in-band and
out-of-band data are stored on the NAND media) used by NAND/ECC
controllers.

Those specific layouts might impact MTD users and thus should be hidden (as
already done in the standard NAND_ECC_HW_SYNDROME implementation).

Clearly state this constraint in the nand_ecc_ctrl struct documentation.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-11-20 00:02:46 -08:00
Boris BREZILLON 57a94e24bc mtd: nand: support ONFI timing mode retrieval for non-ONFI NANDs
Add an onfi_timing_mode_default field to nand_chip and nand_flash_dev in
order to support NAND timings definition for non-ONFI NAND.

NAND that support better timings mode than the default one have to define
a new entry in the nand_ids table.

The default timing mode should be deduced from timings description from
the datasheet and the ONFI specification
(www.onfi.org/~/media/ONFI/specs/onfi_3_1_spec.pdf, chapter 4.15
"Timing Parameters").
You should choose the closest mode that fit the timings requirements of
your NAND chip.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-09-22 11:29:57 -07:00
Brian Norris 5b49ab3e03 Merge l2-mtd/next into l2-mtd/master 2014-08-19 11:57:23 -07:00
Boris BREZILLON b25046b1e5 mtd: nand: fix DocBook warnings on nand_sdr_timings doc
Change the comment type (from /** to /*) to prevent DocBook from
complaining about missing description for nand_sdr_timings fields.

There is currently no need in documenting those fields because they are
fully described in the ONFI specification (which is pointed out in the
comment).

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-08-19 11:55:38 -07:00
Randy Dunlap 7b7d8982f0 mtd: fix linux/mtd/nand.h kernel-doc warning
Fix kernel-doc warning in <linux/mtd/nand.h>:

Warning(..//include/linux/mtd/nand.h:795): No description found for parameter 'ecc'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc:	David Woodhouse <dwmw2@infradead.org>
Cc:	Brian Norris <computersforpeace@gmail.com>
Cc:	linux-mtd@lists.infradead.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-08-19 11:53:06 -07:00
Boris BREZILLON 974647ea8a mtd: nand: add ONFI timing mode to nand_timings converter
Add a converter to retrieve NAND timings from an ONFI NAND timing mode.
At the moment, only SDR NAND timings are supported.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-07-21 19:39:55 -07:00
Boris BREZILLON bb5fd0b6da mtd: nand: define struct nand_timings
Define a struct containing the standard NAND timings as described in NAND
datasheets.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-07-21 19:26:11 -07:00
Ezequiel Garcia 8471bb73ba mtd: Introduce mtd_block_isreserved()
In addition to mtd_block_isbad(), which checks if a block is bad or
reserved, it's needed to check if a block is reserved only (but not
bad). This commit adds an MTD interface for it, in a similar fashion to
mtd_block_isbad().

While here, fix mtd_block_isbad() so the out-of-bounds checking is done
before the callback check.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-07-08 18:38:16 -07:00
Kamal Dasu 66507c7bc8 mtd: nand: Add support to use nand_base poi databuf as bounce buffer
nand_base can be passed a kmap()'d buffers from highmem by
filesystems like jffs2. This results in failure to map the
physical address of the DMA buffer on various contoller
driver on different platforms. This change adds a chip option
to use preallocated databuf as bounce buffers used in
nand_do_read_ops() and nand_do_write_ops().
This allows for specific nand controller driver to set this
option as needed.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-05-20 16:35:32 -07:00
Brian Norris 49c50b97b5 mtd: nand: refactor erase_cmd() to return chip status
The nand_chip::erase_cmd callback previously served a dual purpose; for
one, it allowed a per-flash-chip override, so that AG-AND devices could
use a different erase command than other NAND. These AND devices were
dropped in commit 14c6578683 (mtd: nand:
remove AG-AND support). On the other hand, some drivers (denali and
doc-g4) need to use this sort of callback to implement
controller-specific erase operations.

To make the latter operation easier for some drivers (e.g., ST's new BCH
NAND driver), it helps if the command dispatch and wait functions can be
lumped together, rather than called separately.

This patch does two things:
 1. Pull the call to chip->waitfunc() into chip->erase_cmd(), and return
    the status from this callback
 2. Rename erase_cmd() to just erase(), since this callback does a
    little more than just send a command

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Lee Jones <lee.jones@linaro.org>
2014-05-09 13:19:42 -07:00
David Mosberger e34fcb07a6 mtd: nand: fix GET/SET_FEATURES address on 16-bit devices
GET_FEATURES and SET_FEATURES also need byte-addressing on 16-bit devices.

Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-25 23:31:26 -07:00
Huang Shijie e004debdad mtd: nand: add "page" argument for read_subpage hook
Add the "page" argument for the read_subpage hook. With this argument,
the implementation of this hook could prints out more accurate information
for debugging.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:30 -07:00
Huang Shijie 913618185e mtd: nand: parse out the JEDEC compliant NAND
This patch adds the parsing code for the JEDEC compliant NAND.

Since we need the 0x40 as the column address, this patch also
makes the NAND_CMD_PARAM to use the 8-bit address only.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:27 -07:00
Huang Shijie 7852f8962f mtd: nand: add a helper to get the supported features for JEDEC
Add a helper to get the supported features for JEDEC compliant NAND.
Also add a macro JEDEC_FEATURE_16_BIT_BUS.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:26 -07:00
Huang Shijie d94abba760 mtd: nand: add fields for JEDEC in nand_chip
Add the jedec_version field, and add an anonymous union which
contains the nand_onfi_params and nand_jedec_params.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:26 -07:00
Huang Shijie afbfff03d6 mtd: nand: add the data structures for JEDEC parameter page
Create the nand_jedec_params{} and jedec_ecc_info{} according to
the JESD230A (Revision of JESD230, October 2012).

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:26 -07:00
Brian Norris 3dad2344e9 mtd: nand: force NAND_CMD_READID onto 8-bit bus
The NAND command helpers tend to automatically shift the column address
for x16 bus devices, since most commands expect a word address, not a
byte address. The Read ID command, however, expects an 8-bit address
(i.e., 0x00, 0x20, or 0x40 should not be translated to 0x00, 0x10, or
0x20).

This fixes the column address for a few drivers which imitate the
nand_base defaults. Note that I don't touch sh_flctl.c, since it already
handles this problem slightly differently (note its comment "READID is
always performed using an 8-bit bus").

I have not tested this patch, as I only have x8 parts up for testing at
this point. Hopefully that can change soon...

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-By: Pekon Gupta <pekon@ti.com>
2014-03-10 22:42:22 -07:00
Huang Shijie 3f172cbdfb mtd: nand: remove the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE
There is no reference to these two macros now.
Just remove them.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:22 -07:00
Huang Shijie f02ea4e6a4 mtd: nand: kill the the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE for nand_buffers{}
The patch converts the arrays to buffer pointers for nand_buffers{}.

The cafe_nand.c is the only NAND_OWN_BUFFERS user which allocates
nand_buffers{} itself.

This patch disables the DMA for nand_scan_ident, and restores the DMA
status after we finish the nand_scan_ident. This way, we can get page
size and OOB size and use them to allocate cafe->dmabuf.

Since the cafe_nand.c uses the NAND_ECC_HW_SYNDROME ECC mode, we do not
allocate the buffers for @ecccalc and @ecccode.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-03-10 22:42:22 -07:00
Huang Shijie 4968a4124c mtd: nand: add Intel manufacturer ID
Add the Intel manufacturer Id.
Tested with Intel JS29F32G08ACMD1(4096 + 224) which is ONFI 2.0 compliant
nand.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-20 11:30:52 -08:00
Huang Shijie 3f97c6ff6d mtd: nand: add SanDisk manufacturer ID
Add the manufactor ID for SanDisk.
Make preparation for SanDisk SDTNRGAMA-008G.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-20 11:23:28 -08:00
Uwe Kleine-König 05f7835975 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>
2014-01-14 17:22:37 -08:00
Brian Norris e2e6b7b7d6 mtd: nand: use __packed shorthand
To be consistent with the rest of include/linux/mtd/nand.h, we should
use the __packed shorthand instead of __attribute__((packed)).

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:13:31 -08:00
Brian Norris 8429bb3975 mtd: nand: support Micron READ RETRY
Micron provides READ RETRY support via the ONFI vendor-specific
parameter block (to indicate how many read-retry modes are available)
and the ONFI {GET,SET}_FEATURES commands with a vendor-specific feature
address (to support reading/switching the current read-retry mode).

The recommended sequence is as follows:

  1. Perform PAGE_READ operation
  2. If no ECC error, we are done
  3. Run SET_FEATURES with feature address 89h, mode 1
  4. Retry PAGE_READ operation
  5. If ECC error and there are remaining supported modes, increment the
     mode and return to step 3. Otherwise, this is a true ECC error.
  6. Run SET_FEATURES with feature address 89h, mode 0, to return to the
     default state.

This patch implements the chip->setup_read_retry() callback for
Micron and fills in the chip->read_retries.

Tested on Micron MT29F32G08CBADA, which supports 8 read-retry modes.

The Micron vendor-specific table was checked against the datasheets for
the following Micron NAND:

Needs retry   Cell-type    Part number          Vendor revision    Byte 180
-----------   ---------    ----------------     ---------------    ------------
No            SLC          MT29F16G08ABABA      1                  Reserved (0)
No            MLC          MT29F32G08CBABA      1                  Reserved (0)
No            SLC          MT29F1G08AACWP       1                  0
Yes           MLC          MT29F32G08CBADA      1                  08h
Yes           MLC          MT29F64G08CBABA      2                  08h

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:13:05 -08:00
Brian Norris ba84fb5952 mtd: nand: add generic READ RETRY support
Modern MLC (and even SLC?) NAND can experience a large number of
bitflips (beyond the recommended correctability capacity) due to drifts
in the voltage threshold (Vt). These bitflips can cause ECC errors to
occur well within the expected lifetime of the flash. To account for
this, some manufacturers provide a mechanism for shifting the Vt
threshold after a corrupted read.

The generic pattern seems to be that a particular flash has N read retry
modes (where N = 0, traditionally), and after an ECC failure, the host
should reconfigure the flash to use the next available mode, then retry
the read operation. This process repeats until all bitfips can be
corrected or until the host has tried all available retry modes.

This patch adds the infrastructure support for a
vendor-specific/flash-specific callback, used for setting the read-retry
mode (i.e., voltage threshold).

For now, this patch always returns the flash to mode 0 (the default
mode) after a successful read-retry, according to the flowchart found in
Micron's datasheets. This may need to change in the future if it is
determined that eventually, mode 0 is insufficient for the majority of
the flash cells (and so for performance reasons, we should leave the
flash in mode 1, 2, etc.).

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:12:58 -08:00
Brian Norris 6f0065b012 mtd: nand: add ONFI vendor block for Micron
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
2014-01-13 23:12:53 -08:00
Brian Norris a55e85ce9b mtd: nand: fix misspelling in ONFI parameter field name
s/strenght/strength/

This field isn't used anywhere, so this rename is safe.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2014-01-03 11:22:20 -08:00
Huang Shijie 7db906b79f mtd: nand: rename the cellinfo to bits_per_cell
The @cellinfo fields contains unused information, such as write caching,
internal chip numbering, etc. But we only use it to check the SLC or MLC.

This patch tries to make it more clear and simple, renames the @cellinfo
to @bits_per_cell.

In order to avoiding the bisect issue, this patch also does the following
changes:
  (0) add a macro NAND_CI_CELLTYPE_SHIFT to avoid the hardcode.

  (1) add a helper to parse out the cell type : nand_get_bits_per_cell()

  (2) parse out the cell type for extended-ID chips and the full-id nand chips.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2013-10-27 16:27:04 -07:00
Huang Shijie 1d0ed69ddd mtd: nand: add a helper to check the SLC/MLC nand chip
Add a helper to check if a nand chip is SLC or MLC.
This helper makes the code more readable.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2013-10-27 16:27:04 -07:00
Brian Norris aaadd9819a mtd: nand: remove obsolete 'ecclayout' field
This field is never used, except to print it out.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2013-10-27 16:27:03 -07:00
Huang Shijie 2dc0bdd91b mtd: add ECC info for nand_flash_dev{}
Add an instance of an anonymous struct to store the ECC info for full id
nand chips.
	@ecc.strength_ds: ECC correctability from the datasheet.
	@ecc.step_ds: ECC size required by the @ecc.strength_ds,

These two fields are all from the datasheet.

Also add the necessary macros to make the code simple and clean.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2013-08-30 21:34:45 +01:00