mtd: spi-nor: eon: sort flash_info database

The flash ID is the new primary key into our database. Sort the entry by
it. Keep the most specific ones first, because there might be ID
collisions between shorter and longer ones.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-32-e60548861b10@kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: eon: convert flash_info to new format

The INFOx() macros are going away. Convert the flash_info database to
the new format.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-18-e60548861b10@kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: remove or move flash_info comments

Most of the comments are a relict of the past when the flash_info was
just one table. Most of them are useless. Remove them.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-16-e60548861b10@kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: drop .parse_sfdp

Drop the size parameter to indicate we need to do SFDP, we can do that
because it is guaranteed that the size will be set by SFDP and because
PARSE_SFDP forced the SFDP parsing it must be overwritten.

There is a (very tiny) chance that this might break block protection
support: we now rely on the SFDP reported size of the flash for the
BP calculation. OTOH, if the flash reports its size wrong, we are
in bigger trouble than just having the BP calculation wrong.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-11-e60548861b10@kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: support eon en25qh256a variant

This patch allows accessing the upper 16m on the A variant (EN25QH256A) of
the EN25QH256 that shares same JEDEC ID.

Without this patch, addr_with is detected to be '4' but the read_opcode is
a plain READ (supporting only 3 byte addresses).
Setting PARSE_SFDP is enough to detect the read_opcode READ_4B on the A
variant. READ_4B is not available on the no-A variant.

Both variants support 4-byte address mode (spi_nor_set_4byte_addr_mode)
but that is prone to breaking on unexpected reboots if the reset pin isn't
connected (broken-flash-reset).

The no-A variant supports a 'high bank latch mode' that affects read,
program, and erase commands - similar to the extended address register
(EAR).
The HBL bit is manipulated using the ENHBL (0x67) and EXHBL (0x98)
opcodes.

Should it become necessary to distinguish the two variants in the future,
the A variant sets the SNOR_HWCAPS_READ_1_1_4 SFDP param - the no-A
variant doesn't.

Tested with and without fast read on the A variant only.

Signed-off-by: Leon M. George <leon@georgemail.eu>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220502233310.791565-2-leon@georgemail.eu

mtd: spi-nor: eon: unify function names

To avoid name clashes unify all the function and static object names and
use one of the following prefixes which should be sufficiently unique:
- <vendor>_nor_
- <flash_family>_nor_
- <flash_part>_

There are no functional changes.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20220223134358.1914798-4-michael@walle.cc

mtd: spi-nor: Rework the flash_info flags

Clarify for what the flash_info flags are used for. Split them in
four categories and a bool:
1/ FLAGS: flags that indicate support that is not defined by the JESD216
standard in its SFDP tables.
2/ NO_SFDP_FLAGS: these flags are used when the flash does not define the
SFDP tables. These flags indicate support that can be discovered via
SFDP. Used together with SPI_NOR_SKIP_SFDP flag.
3/ FIXUP_FLAGS: flags that indicate support that can be discovered
via SFDP ideally, but can not be discovered for this particular flash
because the SFDP table that indicates this support is not defined by
the flash. In case the table for this support is defined but has wrong
values, one should instead use a post_sfdp() hook to set the SNOR_F
equivalent flag.
4/ MFR_FLAGS: manufacturer private flags. Used in the manufacturer
fixup hooks to differentiate support between flashes of the same
manufacturer.
5/ PARSE_SFDP: sets info->parse_sfdp to true. All flash_info entries
that support SFDP should be converted to set info->parse_sfdp to true.

SPI NOR flashes that statically declare one of the
SPI_NOR_{DUAL, QUAD, OCTAL, OCTAL_DTR}_READ flags and do not support
the RDSFDP command are gratuiously receiving the RDSFDP command
in the attempt of parsing the SFDP tables. It is not desirable to issue
commands that are not supported, so introduce PARSE_SFDP to help on this
situation.

New flash additions/updates should be declared/updated to use either
PARSE_SFDP or SPI_NOR_SKIP_SFDP. Once all the flash_info entries are
converted to use SPI_NOR_SKIP_SFDP or PARSE_SFDP, we can get rid of the
SPI_NOR_SKIP_SFDP flag and use just the bool nor->info->parse_sfdp to
determine whether to parse SFDP or not. SPI_NOR_SKIP_SFDP flag is kept
just as a way to differentiate whether a flash is converted to the new
flags logic or not.
Support that can be discovered when parsing SFDP should not be duplicated
by explicit flags at flash declaration. All the flash parameters will be
discovered when parsing SFDP. Sometimes manufacturers wrongly define some
fields in the SFDP tables. If that's the case, SFDP data can be amended
with the fixups() hooks. It is not common, but if the SFDP tables are
entirely wrong, and it does not worth the hassle to tweak the SFDP
parameters by using the fixups hooks, or if the flash does not define the
SFDP tables at all, then statically init the flash with the
SPI_NOR_SKIP_SFDP flag and specify the rest of flash capabilities with
the flash info flags.

With time, we want to convert all flashes to use PARSE_SFDP and
stop triggering the SFDP parsing with the
SPI_NOR_{DUAL, QUAD, OCTAL*}_READ flags. Getting rid of the
SPI_NOR_{OCTAL, OCTAL_DTR}_READ trigger is easily achievable,
the rest are a long term goal.

Manufacturer specific flags like USE_CLSR, USE_FSR, SPI_NOR_XSR_RDY,
will be removed in a future series.

No functional changes intended in this patch.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20211207140254.87681-7-tudor.ambarus@microchip.com

mtd: spi-nor: Move Eon bits out of core.c

Create a SPI NOR manufacturer driver for Eon chips, and move the
Eon definitions outside of core.c.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>