Merge tag 'mtd/spi-mem-cont-read-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux into spi-7.2

Miquel Raynal <miquel.raynal@bootlin.com> says:

Aside from preparation changes in the SPI NAND core, the changes carried
here focus on the shared spi-mem layer which is enhanced in order to
bring two new features:

- The possibility to fill a primary and a secondary operation template
  in the direct mapping structure in order to support continuous reads
  in SPI NAND, which may require two different read operations.

- SPI controllers may indicate possible CS instabilities over long
  transfers by setting a boolean. This capability is related to the
  previous one, the need for it has arised while testing SPI NAND
  continuous reads with the Cadence QSPI controller which cannot, under
  certain conditions, keep the CS asserted for the length of
  an eraseblock-large transfer.

As of now, we only use a single operation template when creating SPI
memory direct mappings. With the idea to extend this possibility to 2,
rename the template to reflect that we are currently setting the
"primary" operation, and create a pointer in the same structure to point
to it.

From a user point of view, the op_tmpl name remains but becomes a
pointer, leading to minor changes in both the SPI NAND and SPI NOR
cores.

There is no functional change.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Direct mappings are very static concepts, which allow us to reuse a
template to perform reads or writes in a very efficient manner after a
single initialization. With the introduction of pipelined ECC engines
for SPI controllers, the need to differentiate between an operation with
and without correction has arised. The chosen solution at that time has
been to create new direct mappings for these operations, jumping from 2
to 4 dirmaps per target. Enabling ECC was done by choosing the correct
dirmap.

Today, we need to further parametrize dirmaps. With the goal to enable
continuous reads on a wider range of devices, we will need more
flexibility regarding the read from cache operation template to pick at
run time, for instance to use shorter "continuous read from cache"
variants.

We could create other direct mappings, but it would increase the matrix
by a power of two, bringing the theoretical number of dirmaps to
8 (read/write, ecc, shorter read variants) per target. This grow is not
sustainable, so let's change how dirmaps work - a little bit.

Operations already carry an ECC parameter, use it to indicate whether
error correction is required or not. In practice this change happens
only at the core level, SPI controller drivers do not care about the
direct mapping structure in this case, they just pick whatever is in the
template as a base. As a result, we allow the core to dynamically change
the content of the templates.

He who can do more can do less, so during the checking steps, make sure
to enable the ECC requirement just for the time of the checks.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

This helper is going to be needed in a vendor driver, so expose it.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Since continuous reads may sometimes not be able to go past an erase
block boundary, it has been decided not to attempt longer reads and if
the user request is bigger, it will be split across eraseblocks.

As these request will anyway be handled correctly, there is no reason to
filter out cases where we would go over a target or a die, so drop this
limitation which had a side effect: any request to read more than the
content of an eraseblock would simply not benefit from the continuous
read feature.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

In most scenarios this variant is actually unused (VCR is written in
SSDR mode), but we need to provide an octal variant. The address is 24
bits but is sent over 4 bytes MSB first. This means we need to shift the
register address by one extra byte for the address to be correct.

I didn't catch this initially because the volatile register region is
256 bytes wide, so the write-then-read procedure did work with the small
register addresses I was using at that time: 0 and 1.

Fixes: 44a2f49b9bdc ("mtd: spinand: winbond: W35N octal DTR support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Both W35N02JW and W35N04JW diverge from W35N01JW when it comes to the
"data read" operation in ODTR mode. In order to stuff more address
bits (up to 18), the second command byte is replaced by the most
significant address bits, keeping the number of address bytes to 2.

Fixes: 44a2f49b9bdc ("mtd: spinand: winbond: W35N octal DTR support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Some devices stuff address bits in the double byte opcode (in place of
the repeated byte) in order to be able to increase the size of the
devices, without adding extra address bytes.

Create a flag to identify those devices. When the flag is set, use the
"packed" variant for the read data operation.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Pull MTD updates from Miquel Raynal:
 "MTD changes:

   - mtdconcat finally makes it in, after several years of being merged
     and reverted

   - Baikal SoC support is being removed, so MTD bits are being removed
     as well

   - misc cleanups

  NAND changes:

   - SunXi driver support for new versions of the Allwinner NAND
     controller.

   - DT-binding improvements and cleanups.

   - A few fixes (Realtek ECC and Winbond SPI NAND), aside with the
     usual load of misc changes.

  SPI NOR fixes:

   - Enable die erase on MT35XU02GCBA. We knew this flash needed this
     fixup since 7f77c561e227 ("mtd: spi-nor: micron-st: add TODO for
     fixing mt35xu02gcba") but did not add it due to lack of hardware to
     test on.

   - Fix locking on some Winbond w25q series flashes.

   - Fix Auto Address Increment (AAI) writes on SST that flashes that
     start on odd address. The write enable latch needs to be set again
     after the single byte program"

* tag 'mtd/for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (44 commits)
  mtd: spinand: winbond: Declare the QE bit on W25NxxJW
  mtd: spi-nor: micron-st: Enable die erase support for MT35XU02GCBA
  mtd: spi-nor: winbond: Fix locking support for w25q256jw
  mtd: spi-nor: sst: Fix write enable before AAI sequence
  mtd: spi-nor: winbond: Fix locking support for w25q64jvm
  mtd: spi-nor: winbond: Fix locking support for w25q256jwm
  dt-bindings: mtd: mxc-nand: add missing compatible string and ref to nand-controller-legacy.yaml
  dt-bindings: mtd: gpmi-nand: ref to nand-controller-legacy.yaml
  dt-bindings: mtd: refactor NAND bindings and add nand-controller-legacy.yaml
  mtd: spinand: winbond: Clarify when to enable the HS bit
  mtd: rawnand: sunxi: introduce maximize variable user data length
  mtd: rawnand: sunxi: fix typos in comments
  mtd: rawnand: sunxi: change error prone variable name
  mtd: rawnand: sunxi: remove dead code
  mtd: rawnand: sunxi: make the code more self-explanatory
  mtd: rawnand: sunxi: replace hard coded value by a define - take2
  mtd: rawnand: sunxi: do not count BBM bytes twice
  mtd: rawnand: sunxi: fix sunxi_nfc_hw_ecc_read_extra_oob
  mtd: rawnand: sunxi: sunxi_nand_ooblayout_free code clarification
  mtd: cmdlinepart: use a flexible array member
  ...

The callbacks into the MIPS RB532 platform to read the GPIO pin
indicating that the NAND chip is ready are oldschool and does
not assign GPIOs as properties to the NAND device.

Add a capability to the generic platform NAND chip driver to use
a GPIO line to detect if a NAND chip is ready and override the
platform-local drv_ready() callback with this check if the GPIO
is present.

This makes it possible to drop the legacy include header
<linux/gpio.h> from the RB532 devices.

Signed-off-by: Linus Walleij <linusw@kernel.org>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>