mtd: rawnand: gpmi: Add large oob bch setting support

The code change proposes a new way to set bch geometry for large oob
NAND (oobsize > 1KB). In this case, previous implementation can NOT
guarantee the bad block mark always locates in data chunk, so we need a
new way to do it. The general idea is,

1.Try all ECC strength from the maximum ecc that controller can support
to minimum value required by NAND chip, any ECC strength makes the
BBM locate in data chunk can be eligible.

2.If none of them works, using separate ECC for meta, which will add
one extra ecc with the same ECC strength as other data chunks. This
extra ECC can guarantee BBM located in data chunk, also we need to
check if oob can afford it.

Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220412025246.24269-6-han.xu@nxp.com

mtd: rawnand: gpmi: Rename the variable ecc_chunk_size

There is only one variable ecc_chunk_size in bch_geometry data
structure but two different field in BCH registers. The data0_size in
BCH_FLASH0LAYOUT0 and datan_size in BCH_FLASH0LAYOUT1 should have
dedicate variable since they might set to different values in some
cases. For instance, if need dedicate ecc for meta area, the data0_size
should be 0 rather than datan_size, but for all other cases, data0_size
still equals to datan_size and it won't bring any function change.

Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220412025246.24269-5-han.xu@nxp.com

mtd: rawnand: Use more recent ONFI specification wording

In particular, first ONFI specifications referred to SDR modes as
asynchronous modes, which is not the term we usually have in mind. The
spec has then been updated, so do the same here in the NAND subsystem to
avoid any possible confusion.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210505213750.257417-7-miquel.raynal@bootlin.com

mtd: rawnand: gpmi: Implement exec_op

The gpmi driver performance suffers from NAND operations being split
in multiple small DMA transfers. This has been forced by the NAND layer
in the former days, but now with exec_op we can use the controller as
intended.

With this patch gpmi_nfc_exec_op becomes the main entry point to NAND
operations. Here all instructions are collected and chained as separate
DMA transfers. In the end whole chain is fired and waited to be
finished. gpmi_nfc_exec_op only does the hardware operations, bad block
marker swapping and buffer scrambling is done by the callers. It's worth
noting that the nand_*_op functions always take the buffer lengths for
the data that the NAND chip actually transfers. When doing BCH we have
to calculate the net data size from the raw data size in some places.

This patch has been tested with 2048/64 and 2048/128 byte NAND on
i.MX6q. mtd_oobtest, mtd_subpagetest and mtd_speedtest run without
errors. nandbiterrs, nandpagetest and nandsubpagetest userspace tests
from mtdutils run without errors and UBIFS can successfully be mounted.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: gpmi: Remove unnecessary variables

this->page_buffer_virt and this->payload_virt are always set to the same
value, so drop the former and just use the latter. Same for
this->page_buffer_virt and this->payload_virt.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: gpmi: remove unused variable

The "private" member of struct gpmi_nand_data isn't used anywhere.
Remove it.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: gpmi: move all driver code into single file

This moves the whole driver into a single C file. The filename gpmi-lib
implies that it implements library functions, but in fact there are
several cases where functions in gpmi-lib.c call back into functions in
gpmi-nand.c. With this one has to constantly jump between those two
files, so moving it into a single file improves readability, even when
the file gets quite large.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: gpmi: Introduce GPMI_IS_MXS() macro

Introduce a GPMI_IS_MXS() macro to take into account the cases
when mx23 or mx28 are used, which helps readability.

Signed-off-by: Fabio Estevam <festevam@gmail.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: gpmi: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: rawnand: gpmi: remove direct_dma_map_ok from driver data struct

Instead of putting direct_dma_map_ok into driver struct pass it around
between functions to make the code more readable.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: rawnand: gpmi: pass buffer and len around

Instead of putting the buffer and len passed in from the mtd core
into the private data struct, just pass it around in the GPMI
drivers functions. This makes the lifetime of the variables more
clear and the code easier to follow.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: rawnand: gpmi: drop dma_ops_type

The GPMI nand driver puts dma_ops_type in its private data struct. Based
on the ops type the DMA callback handler unmaps previously mapped
buffers. Instead of unmapping the buffers in the DMA callback handler,
do this in the caller directly which waits for the DMA transfer to
finish. This makes the whole dma_ops_type mechanism unnecessary.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

mtd: rawnand: gpmi: use core timings instead of an empirical derivation

GPMI driver timings derivation looks very empirical and does not use
the known timings that the core wants to use with the NAND chip, by
using local defined constants that have no special meaning from the
outside world.

Simplify the way all of this is computed and use the NAND core's SDR
timings.

Integrity of the reads/writes has been checked with nandbiterrs, speed
improvements with flash_speed on a Freescale i.MX6 DualLite/Solo SABRE
Automotive Board. Measures are below, variations of less than 150kiB/s
between tests are common and then not significant. Speeds using mode 5
are the same, while speeds using mode 0 are quite improved (+40/50%
from non-optimal computation).

Forcing timings mode 0:

=======================

Before this patch:
------------------
eraseblock write speed is 2298 KiB/s
eraseblock read speed is 3636 KiB/s
page write speed is 2136 KiB/s
page read speed is 3316 KiB/s
2 page write speed is 2199 KiB/s
2 page read speed is 3468 KiB/s

After this patch:
-----------------
eraseblock write speed is 3232 KiB/s
eraseblock read speed is 5663 KiB/s
page write speed is 2915 KiB/s
page read speed is 4904 KiB/s
2 page write speed is 3084 KiB/s
2 page read speed is 5267 KiB/s

Forcing timings mode 5:
=======================

Before this patch:
------------------
eraseblock write speed is 4338 KiB/s
eraseblock read speed is 14883 KiB/s
page write speed is 3786 KiB/s
page read speed is 12800 KiB/s
2 page write speed is 4076 KiB/s
2 page read speed is 14065 KiB/s

After this patch:
-----------------
eraseblock write speed is 4309 KiB/s
eraseblock read speed is 14712 KiB/s
page write speed is 3764 KiB/s
page read speed is 12673 KiB/s
2 page write speed is 4076 KiB/s
2 page read speed is 14065 KiB/s

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

mtd: rawnand: gpmi: support ->setup_data_interface()

Until now the GPMI driver had its own timings logic while the core
already handles that and request the NAND controller drivers to support
the ->setup_data_interface() hook. Implement that hook by reusing the
already existing function. No real glue is necessary between core timing
delays and GPMI registers because the driver already translates the
ONFI timing modes into register values.

Make use of the core's tREA, tRLOH and tRHOH values that allow computing
more precise timings for mode [0-3] and get significantly better values
(+20% with an i.MX6 Sabre Auto board). Otherwise use the existing logic.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Han Xu <han.xu@nxp.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>