mtd: rawnand: Use the new ECC engine type enumeration

Mechanical switch from the legacy "mode" enumeration to the new
"engine type" enumeration in drivers and board files.

The device tree parsing is also updated to return the new enumeration
from the old strings.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-11-miquel.raynal@bootlin.com

mtd: rawnand: Separate the ECC engine type and the ECC byte placement

The use of "syndrome" placement should not be encoded in the ECC
engine mode/type.

Create a "placement" field in NAND chip and change all occurrences of
the NAND_ECC_HW_SYNDROME enumeration to be just NAND_ECC_HW and
possibly a placement entry like NAND_ECC_PLACEMENT_INTERLEAVED.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200827085208.16276-10-miquel.raynal@bootlin.com

mtd: rawnand: s/data_interface/interface_config/

The name/suffix data_interface is a bit misleading in that the field
or functions actually represent a configuration that can be applied by
the controller/chip. Let's rename all fields/functions/hooks that are
worth renaming.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: Stop using nand_release()

This helper is not very useful and very often people get confused:
they use nand_release() instead of nand_cleanup().

Let's stop using nand_release() by calling mtd_device_unregister() and
nand_cleanup() directly.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/linux-mtd/20200519130035.1883-12-miquel.raynal@bootlin.com

mtd: rawnand: denali: Delete items from the list in the _remove() path

Denali driver keeps track of devices with a list. Delete items of this
list as long as they are not in use anymore.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lore.kernel.org/linux-mtd/20200519130035.1883-11-miquel.raynal@bootlin.com

mtd: rawnand: Rename a NAND chip option

NAND controller drivers can set the NAND_USE_BOUNCE_BUFFER flag to a
chip 'option' field. With this flag, the core is responsible of
providing DMA-able buffers.

The current behavior is to not force the use of a bounce buffer when
the core thinks this is not needed. So in the end the name is a bit
misleading, because in theory we will always have a DMA buffer but in
practice it will not always be a bounce buffer.

Rename this flag NAND_USES_DMA to be more accurate.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20200507105241.14299-4-miquel.raynal@bootlin.com

mtd: rawnand: denali: add more delays before latching incoming data

The Denali IP have several registers to specify how many clock cycles
should be waited between falling/rising signals. You can improve the
NAND access performance by programming these registers with optimized
values.

Because struct nand_sdr_timings represents the device requirement
in pico seconds, denali_setup_data_interface() computes the register
values by dividing the device timings with the clock period.

Marek Vasut reported this driver in the latest kernel does not work
on his SOCFPGA board. (The on-board NAND chip is mode 5)

The suspicious parameter is acc_clks, so this commit relaxes it.

The Denali NAND Flash Memory Controller User's Guide describes this
register as follows:

acc_clks
signifies the number of bus interface clk_x clock cycles,
controller should wait from read enable going low to sending
out a strobe of clk_x for capturing of incoming data.

Currently, acc_clks is calculated only based on tREA, the delay on the
chip side. This does not include additional delays that come from the
data path on the PCB and in the SoC, load capacity of the pins, etc.

This relatively becomes a big factor on faster timing modes like mode 5.

Before supporting the ->setup_data_interface() hook (e.g. Linux 4.12),
the Denali driver hacks acc_clks in a couple of ways [1] [2] to support
the timing mode 5.

We would not go back to the hard-coded acc_clks, but we need to include
this factor into the delay somehow. Let's say the amount of the additional
delay is 10000 pico sec.

In the new calculation, acc_clks is determined by timings->tREA_max +
data_setup_on_host.

Also, prolong the RE# low period to make sure the data hold is met.

Finally, re-center the data latch timing for extra safety.

[1] https://github.com/torvalds/linux/blob/v4.12/drivers/mtd/nand/denali.c#L276
[2] https://github.com/torvalds/linux/blob/v4.12/drivers/mtd/nand/denali.c#L282

Reported-by: Marek Vasut <marex@denx.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200317071821.9916-1-yamada.masahiro@socionext.com

mtd: rawnand: denali: deassert write protect pin

If the write protect signal from this IP is connected to the NAND
device, this IP can handle the WP# pin via the WRITE_PROTECT
register.

The Denali NAND Flash Memory Controller User's Guide describes
this register like follows:

When the controller is in reset, the WP# pin is always asserted
to the device. Once the reset is removed, the WP# is de-asserted.
The software will then have to come and program this bit to
assert/de-assert the same.

1 - Write protect de-assert
0 - Write protect assert

The default value is 1, so the write protect is de-asserted after
the reset is removed. The driver can write to the device unless
someone has explicitly cleared register before booting the kernel.

The boot ROM of some UniPhier SoCs (LD4, Pro4, sLD8, Pro5) is the
case; the boot ROM clears the WRITE_PROTECT register when the system
is booting from the NAND device, so the NAND device becomes read-only.

Set it to 1 in the driver in order to allow the write access to the
device.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200127123934.11847-1-yamada.masahiro@socionext.com

mtd: rawnand: denali: remove hard-coded DENALI_DEFAULT_OOB_SKIP_BYTES

As commit 0d55c668b218 (mtd: rawnand: denali: set SPARE_AREA_SKIP_BYTES
register to 8 if unset") says, there were three solutions discussed:

[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

At that time, [3] was chosen because I did not have enough information
about the other platforms than UniPhier.

That commit also says "The preferred value may vary by platform. If so,
please trade up to a different solution." My intention was to replace
[3] with [2], not keep both [2] and [3].

Now that we have switched to [2] for SOCFPGA's SPARE_AREA_SKIP_BYTES=2,
[3] should be removed. This should be OK because denali_pci.c just
gets back to the original behavior.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali_dt: Add support for configuring SPARE_AREA_SKIP_BYTES

The SPARE_AREA_SKIP_BYTES register is reset when the controller reset
signal is toggled. Yet, this register must be configured to match the
content of the NAND OOB area. The current default value is always set
to 8 and is programmed into the hardware in case the hardware was not
programmed before (e.g. in a bootloader) with a different value. This
however does not work when the block is reset properly by Linux.

On Altera SoCFPGA CycloneV, ArriaV and Arria10, which are the SoCFPGA
platforms which support booting from NAND, the SPARE_AREA_SKIP_BYTES
value must be set to 2. On Socionext Uniphier, the value is 8. This
patch adds support for preconfiguring the default value and handles
the special SoCFPGA case by setting the default to 2 on all SoCFPGA
platforms, while retaining the original behavior and default value of
8 on all the other platforms.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
To: linux-mtd@lists.infradead.org
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: clean up coding style

Eliminate the following reports from 'scripts/checkpatch.pl --strict'.

CHECK: Prefer kernel type 'u8' over 'uint8_t'
CHECK: Prefer kernel type 'u32' over 'uint32_t'
CHECK: Alignment should match open parenthesis

I slightly changed denali_check_erased_page() to shorten it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove DENALI_NR_BANKS macro

Use the runtime-detected denali->nbanks instead of hard-coded
DENALI_NR_BANKS (=4).

The actual number of banks depends on the IP configuration, and
can be less than DENALI_NR_BANKS. It is pointless to touch
registers of unsupported banks.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: decouple controller and NAND chips

Currently, this driver sticks to the legacy NAND model because it was
upstreamed before commit 2d472aba15ff ("mtd: nand: document the NAND
controller/NAND chip DT representation"). However, relying on the
dummy_controller is already deprecated.

Switch over to the new controller/chip representation.

The struct denali_nand_info has been split into denali_controller
and denali_chip, to contain the controller data, per-chip data,
respectively.

One problem is, this commit changes the DT binding. So, as always,
the backward compatibility must be taken into consideration.

In the new binding, the controller node expects

#address-cells = <1>;
#size-cells = <0>;

... since the child nodes represent NAND chips.

In the old binding, the controller node may have subnodes, but they
are MTD partitions.

The denali_dt_is_legacy_binding() exploits it to distinguish old/new
platforms.

Going forward, the old binding is only allowed for existing DT files.
I updated the binding document.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: use bool type instead of int where appropriate

Use 'bool' type for the following boolean parameters.

- write (write or read?)
- dma_avail (DMA engine available or not?)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: switch over to ->exec_op() from legacy hooks

Implement ->exec_op(), and remove the deprecated hooks.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove unneeded casts in denali_{read, write}_pio

Since (u32 *) can accept an opaque pointer, the explicit casting
from (void *) to (u32 *) is redundant. Change the function argument type
to remove the casts.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: refactor raw page accessors

The Denali IP adopts the syndrome page layout (payload and ECC are
interleaved). The *_page_raw() and *_oob() callbacks are complicated
because they must hide the underlying layout used by the hardware,
and always return contiguous in-band and out-of-band data.

The Denali IP cannot reuse nand_{read,write}_page_raw_syndrome()
in nand_base.c because its hardware ECC engine skips some of first
bytes in OOB. That is why this driver implements specially-crafted
*_page_raw() and *_oob() hooks.

Currently, similar code is duplicated to reorganize the data layout.
For example, denali_read_page_raw() and denali_write_page_raw() look
almost the same. The complexity is partly due to the DMA transfer
used for better performance of *_page_raw() accessors.

On second thought, we do not need to care about their performance
because MTD_OPS_RAW is rarely used.

Let's focus on code cleanups rather than the performance. This commit
removes the internal buffer for DMA, and factors out as much code as
possible.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: use more nand_chip pointers for internal functions

With the recent refactoring, the NAND driver hooks now take a pointer
to nand_chip. Add to_denali() in order to convert (struct nand_chip *)
to (struct denali_nand_info *) directly. It is more useful than the
current mtd_to_denali().

I changed some helper functions to take (struct nand_chip *). This will
avoid pointer conversion back and forth, and ease further development.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Get rid of chip->chipsize

The target size can now be returned by nanddev_get_targetsize(). Get
rid of the chip->chipsize field and use this helper instead.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Fill memorg during detection

If we want to use the generic NAND layer, we need to have the memorg
struct appropriately filled. Patch the detection code to fill this
struct.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove unused function argument 'raw'

This argument is not used at all.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove unneeded denali_reset_irq() call

This code was added by commit 26d266e10e5e ("mtd: nand: denali: fix
raw and oob accessors for syndrome page layout"), but I do not see
sensible reason.

The IRQ flags are correctly reset by denali_cmd_ctrl(), so this code
is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove ->erase hook

Commit f9ebd1bb4103 ("mtd: rawnand: Deprecate ->erase()") discouraged
the use of this hook, so I am happy to follow the suggestion.

Although the Denali IP provides a special MAP10 command for erasing,
using it would not buy us much. The Denali IP actually works with the
generic erasing by single_erase() + ->cmdfunc hook (nand_command_lp)
+ ->cmd_ctrl hook (denali_cmd_ctrl).

This method is also deprecated, but denali_erase() can go away
irrespective of ->exec_op conversion.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: get ->setup_data_interface() working again

Commit 7a08dbaedd36 ("mtd: rawnand: Move ->setup_data_interface() to
nand_controller_ops") missed to invert the if-conditonal for denali.
Since then, the Denali NAND driver cannnot invoke setup_data_interface.

Fixes: 7a08dbaedd36 ("mtd: rawnand: Move ->setup_data_interface() to nand_controller_ops")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>

mtd: rawnand: Deprecate the dummy_controller field

We try to force NAND controller drivers to properly separate the NAND
controller object from the NAND chip one, so let's deprecate the dummy
controller object embedded in nand_chip to encourage them to create
their own instance.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove denali_reset_banks()

In nand_scan_ident(), the controller driver resets every NAND chip.
This is done by sending NAND_CMD_RESET. The Denali IP provides
another way to do the equivalent thing; if a bit is set in the
DEVICE_RESET register, the controller sends the RESET command to
the corresponding device. denali_reset_banks() uses it to reset
all devices beforehand.

This redundant reset sequence was needed to know the actual number
of chips before calling nand_scan_ident(); if DEVICE_RESET fails,
there is no chip in that chip select. Then, denali_reset_banks()
sets denali->max_banks to the number of detected chips.

As commit f486287d2372 ("mtd: nand: denali: fix bank reset function
to detect the number of chips") explained, nand_scan_ident() issued
Set Features (0xEF) command to all CS lines, some of which may not be
connected with a chip. Then, the driver would wait for R/B# response,
which never happens.

This problem was solved by commit 107b7d6a7ad4 ("mtd: rawnand: avoid
setting again the timings to mode 0 after a reset"). In the current
code, nand_setup_data_interface() is called from nand_scan_tail(),
which is invoked after the chip detection.

Now, we can really remove the redundant denali_nand_banks() by simply
passing the maximum number of chip selects supported by this IP
(typically 4 or 8) to nand_scan(). Let's leave all the chip detection
process to nand_scan_ident().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: remove ->dev_ready() hook

The Denali NAND IP has no way to read out the current signal level
of the R/B# pin. Instead, denali_dev_ready() checks if the R/B#
transition has already happened. (The INTR__INT_ACT interrupt is
asserted at the rising edge of the R/B# pin.) It is not a correct
way to implement the ->dev_ready() hook.

In fact, it has a drawback; in the nand_scan_ident phase, the chip
detection iterates over maxchips until it fails to find a homogeneous
chip. For the last loop, nand_reset() fails if no chip is there.

If ->dev_ready hook exists, nand_command(_lp) calls nand_wait_ready()
after NAND_CMD_RESET. However, we know denali_dev_ready() never
returns 1 unless there exists a chip that toggles R/B# in that chip
select. Then, nand_wait_ready() just ends up with wasting 400 msec,
in the end, shows the "timeout while waiting for chip to become ready"
warning.

Let's remove the mis-implemented dev_ready hook, and fallback to
sending the NAND_CMD_STATUS and nand_wait_status_ready(), which
bails out more quickly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Move ->setup_data_interface() to nand_controller_ops

->setup_data_interface() is a controller specific method and should
thus be placed in nand_controller_ops.

In order to make that work with controllers that support keeping
pre-configured timings we need to add a new NAND_KEEP_TIMINGS flag to
inform the core it should skip the timings selection step.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Deprecate the ->select_chip() hook

Now that the CS line to be selected is passed to ->exec_op() and
stored in chip->cur_cs and after patching all drivers implementing
->exec_op() to stop implementing this method, we can deprecate it by
moving it to the nand_legacy structure.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: set SPARE_AREA_SKIP_BYTES register to 8 if unset

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>

mtd: rawnand: Deprecate ->erase()

The ->erase() hook have been overloaded by some drivers for bad reasons:
either the driver was not fitting in the NAND framework and should have
been an MTD driver (docg4), or the driver uses a specific path for the
ERASE operation (denali), instead of implementing it generically.
In any case, we should discourage people from overloading this method
and encourage them to implement ->exec_op() instead.

Move the ->erase() hook to the nand_legacy struct to make it clear.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Deprecate ->dev_ready() and ->waitfunc()

Those hooks have been replaced by ->exec_op(). Move them to the
nand_legacy struct.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Deprecate ->cmd_ctrl() and ->cmdfunc()

Those hooks have been replaced by ->exec_op(). Move them to the
nand_legacy struct.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Deprecate ->{read, write}_{byte, buf}() hooks

All those hooks have been replaced by ->exec_op(). Move them to the
nand_legacy struct.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->setup_data_interface()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the chip->setup_data_interface() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->erase()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the chip->erase() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->waitfunc()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the chip->waitfunc() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->dev_ready()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the chip->dev_ready() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->cmd_ctrl()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the chip->cmd_ctrl() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->select_chip()

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle the chip->select_chip() hook.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->write_xxx() hooks

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle all chip->write_xxx() hooks at once.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to chip->read_xxx() hooks

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle all chip->read_xxx() hooks at once.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to ecc->write_xxx() hooks

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle all ecc->write_xxx() hooks at once.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to ecc->read_xxx() hooks

Let's make the raw NAND API consistent by patching all helpers and
hooks to take a nand_chip object instead of an mtd_info one or
remove the mtd_info object when both are passed.

Let's tackle all ecc->read_xxx() hooks at once.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to nand_release()

Let's make the raw NAND API consistent by patching all helpers to
take a nand_chip object instead of an mtd_info one.

Now is nand_release()'s turn.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Pass a nand_chip object to nand_scan()

Let's make the raw NAND API consistent by patching all helpers to take
a nand_chip object instead of an mtd_info one.

We start with nand_scan().

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: fix a race condition when DMA is kicked

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
586a2c52909d ("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: 586a2c52909d ("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>

mtd: rawnand: denali: use SPDX-License-Identifier and fix license mismatch

Use SPDX-License-Identifier instead of the license boilerplates.

This conversion makes it easier for us to scan the license, then
I notice license mismatch problems.

The license blocks in denali* indicate GPL-2.0 "only", while the
MODULE_LICENSE in denali.c and denali_dt.c is GPL-2.0 "or later"
as explained in include/linux/module.h as follows:

"GPL" [GNU Public License v2 or later]
"GPL v2" [GNU Public License v2]

I fixed the MODULE_LICENSE tags, assuming the license blocks are
the authors' intention.

Also, add missing MODULE_DESCRIPTION/AUTHOR to denali.c

While I am touching the license things, I added my credit to denali.c
because this driver was largely re-written by me in 2017.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: Get rid of the ->read_word() hook

Commit c120e75e0e7d ("mtd: nand: use read_oob() instead of cmdfunc()
for bad block check") removed this only user of the ->read_word()
method but kept the hook in place. Remove it now.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: do not pass zero maxchips to nand_scan()

Commit 49aa76b16676 ("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: 49aa76b16676 ("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>

mtd: rawnand: denali: convert to nand_scan()

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>

mtd: rawnand: denali: optimize timing parameters for data interface

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>

mtd: rawnand: denali: use helper function for ecc setup

Use the NAND core helper function nand_ecc_choose_conf to tune
the ECC parameters instead of the function locally defined.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: denali: fix probe function error path

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>

mtd: nand: move raw NAND related code to the raw/ subdir

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>