[ Upstream commit 0d55c668b2 ]
NAND devices need additional data area (OOB) for error correction,
but it is also used for Bad Block Marker (BBM). In many cases, the
first byte in OOB is used for BBM, but the location actually depends
on chip vendors. The NAND controller should preserve the precious
BBM to keep track of bad blocks.
In Denali IP, the SPARE_AREA_SKIP_BYTES register is used to specify
the number of bytes to skip from the start of OOB. The ECC engine
will automatically skip the specified number of bytes when it gets
access to OOB area.
The same value for SPARE_AREA_SKIP_BYTES should be used between
firmware and the operating system if you intend to use the NAND
device across the control hand-off.
In fact, the current denali.c code expects firmware to have already
set the SPARE_AREA_SKIP_BYTES register, then reads the value out.
If no firmware (or bootloader) has initialized the controller, the
register value is zero, which is the default after power-on-reset.
In other words, the Linux driver cannot initialize the controller
by itself.
Some possible solutions are:
[1] Add a DT property to specify the skipped bytes in OOB
[2] Associate the preferred value with compatible
[3] Hard-code the default value in the driver
My first attempt was [1], but in the review process, [3] was suggested
as a counter-implementation.
(https://lore.kernel.org/patchwork/patch/983055/)
The default value 8 was chosen to match to the boot ROM of the UniPhier
platform. The preferred value may vary by platform. If so, please
trade up to a different solution.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I thought the read-back of the DMA_ENABLE register was unnecessary
(at least it is working on my boards), then deleted it in commit
586a2c5290 ("mtd: nand: denali: squash denali_enable_dma() helper
into caller"). Sorry, I was wrong - it caused a timing issue on
Cyclone5 SoCFPGAs.
Revive the register read-back, commenting why this is necessary.
Fixes: 586a2c5290 ("mtd: nand: denali: squash denali_enable_dma() helper into caller")
Cc: <stable@vger.kernel.org>
Reported-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Commit 49aa76b166 ("mtd: rawnand: do not execute nand_scan_ident()
if maxchips is zero") gave a new meaning for calling nand_scan_ident()
with maxchips=0.
It is a special usage for some drivers such as docg4, but actually
the Denali driver may pass maxchips=0 to nand_scan() when the driver
is enabled but no NAND chip is found on the board for some reasons.
If nand_scan_with_ids() is called with maxchips=0, nand_scan_ident()
is skipped, then nand_set_defaults() is skipped as well. Thus, the
driver must set chip->controller beforehand. Otherwise, nand_attach()
causes NULL pointer dereference.
In fact, the Denali controller knows the number of connected chips
before calling nand_scan_ident(); if DEVICE_RESET fails, there is no
chip in that chip select. Then, denali_reset_banks() sets the maxchips
to the number of detected chips. If no chip is found, maxchips is zero.
In this case, there is no point for calling nand_scan() because we know
it will fail for sure. Let's make the probe function fail immediately.
Fixes: 49aa76b166 ("mtd: rawnand: do not execute nand_scan_ident() if maxchips is zero")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Two helpers have been added to the core to do all kind of controller
side configuration/initialization between the detection phase and the
final NAND scan. Implement these hooks so that we can convert the driver
to just use nand_scan() instead of the nand_scan_ident() +
nand_scan_tail() pair.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit improves the ->setup_data_interface() hook.
The denali_setup_data_interface() needs the frequency of clk_x
and the ratio of clk_x / clk.
The latter is currently hardcoded in the driver, like this:
#define DENALI_CLK_X_MULT 6
The IP datasheet requires that clk_x / clk be 4, 5, or 6. I just
chose 6 because it is the most defensive value, but it is not optimal.
By getting the clock rate of both "clk" and "clk_x", the driver can
compute the timing values more precisely.
To not break the existing platforms, the fallback value, 50 MHz is
provided. It is true for all upstreamed platforms.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
An error after nand_scan_tail() should trigger a nand_cleanup().
The helper mtd_device_register() returns an error code that should
be checked and nand_cleanup() called accordingly.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
As part of the process of sharing more code between different NAND
based devices, we need to move all raw NAND related code to the raw/
subdirectory.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
