Drivers setting NAND_ECC_CUSTOM_PAGE_ACCESS are supposed to handle the
full read/write page sequence, and waiting for a page to actually be
programmed is part of this write-page sequence.
This is also what is done in ->write_oob_xxx() hooks, so let's do that in
->write_page_xxx() as well to make it consistent.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Now that the core NAND subsystem has support for on-die ECC, this commit
brings the necessary code to support on-die ECC on Micron NANDs.
In micron_nand_init(), we detect if the Micron NAND chip supports on-die
ECC mode, by checking a number of conditions:
- It must be an ONFI NAND
- It must be a SLC NAND
- Enabling *and* disabling on-die ECC must work
- The on-die ECC must be correcting 4 bits per 512 bytes of data. Some
Micron NAND chips have an on-die ECC able to correct 8 bits per 512
bytes of data, but they work slightly differently and therefore we
don't support them in this patch.
Then, if the on-die ECC cannot be disabled (some Micron NAND have on-die
ECC forcefully enabled), we bail out, as we don't support such
NANDs. Indeed, the implementation of raw_read()/raw_write() make the
assumption that on-die ECC can be disabled. Support for Micron NANDs
with on-die ECC forcefully enabled can easily be added, but in the
absence of such HW for testing, we preferred to simply bail out.
If the on-die ECC is supported, and requested in the Device Tree, then
it is indeed enabled, by using custom implementations of the
->read_page(), ->read_page_raw(), ->write_page() and ->write_page_raw()
operation to properly handle the on-die ECC.
In the non-raw functions, we need to enable the internal ECC engine
before issuing the NAND_CMD_READ0 or NAND_CMD_SEQIN commands, which is
why we set the NAND_ECC_CUSTOM_PAGE_ACCESS option at initialization
time (it asks the NAND core to let the NAND driver issue those
commands).
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Move Micron specific initialization logic into nand_micron.c. This is
part of the "separate vendor specific code from core" cleanup process.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Richard Weinberger <richard@nod.at>
Boris Brezillon