Implement read of OOB area only. When using column and sector size
properties, only parts of the page can be read. However, this works
only when hardware ECC is disabled, otherwise the ECC engine would
ruin the data in the buffer. To allow OOB only reads, three points
had to be addressed:
- Set ECC mode per command.
- Handle NAND_CMD_READOOB seperate. Make sure column and sector
size is correctly set up, while disabling ECC.
- Now, the OOB data end up at the beginning of the buffer. Remove
the special handling of OOB (spareonly).
Especially bad block scans benefit from this change. On a 512MiB
SLC NAND device, the bad block scan took 1.5s less than before.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Since we do not support sub-page writes anyway, reading the page
back to the controller on SEQIN command is not required. Remove
the page read on SEQIN.
However, the column/page values relevant to the SEQIN command, hence
set the column/row address on SEQIN command.
Signed-off-by: Stefan Agner <stefan@agner.ch>
To improve performance we remember the current page in the buffer
and avoid reading it twice. This implicit page cache increases
complexity while does not increase performance in real world cases.
This patch removes that feature.
Acked-by: Bill Pringlemeir <bpringlemeir@nbsps.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Testing showed, that commands like STATUS made the buffer dirty
when executed with NFC_SECSZ set to the page size. It looks
like the controller transfers bogus data when this register
is configured. When setting it to 0, the buffer does not get
altered while the status command still seems to work flawless.
Signed-off-by: Stefan Agner <stefan@agner.ch>
The driver tries to re-use the page buffer by storing the page
number of the current page in the buffer. The page is only read
if the requested page number is not currently in the buffer. When
a block is erased, the page number is marked as invalid if the
erased page equals the one currently in the cache. However, since
a erase block consists of multiple pages, also other page numbers
could be affected.
The commands to reproduce this issue (on a written page):
> nand dump 0x800
> nand erase 0x0 0x20000
> nand dump 0x800
The second nand dump command returns the data from the buffer,
while in fact the page is erased (0xff).
Avoid the hassle to calculate whether the page is affected or not,
but set the page buffer unconditionally to invalid instead.
Signed-off-by: Stefan Agner <stefan@agner.ch>
This patch disables subpage writes for vf610_nfc nand
driver. This is required, as without this fix, writing
unaligned u-boot images with DFU results in a hang.
Trying to write unalgined binary images also results
in a hang, without disabling subpage writes.
Patch has been tested on a Colibri VF61 module.
Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
This adds initial support for Freescale NFC (NAND Flash Controller)
found in ARM Vybrid SoC's, Power Architecture MPC5125 and others.
The driver is called vf610_nfc since this is the first supported
and tested hardware platform supported by the driver.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Bill Pringlemeir <bpringlemeir@nbsps.com>
