mtd: spi-nor: use kernel sized types instead of c99 types

The kernel offers and prefers the kernel sized types instead of the c99
types when not in the uapi directory, use them.

Link: https://lore.kernel.org/r/20231101145853.524045-2-tudor.ambarus@linaro.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: make sector_size optional

Most of the (old, non-SFDP) flashes use a sector size of 64k. Make that
a default value so it can be optional in the flash_info database.

As a preparation for conversion to the new database format, set the
sector size to zero if the default value is used. This way, the actual
change is happening with this patch ant not with a later conversion
patch.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-10-e60548861b10@kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: convert .n_sectors to .size

.n_sectors is rarely used. In fact it is only used in swp.c and to
calculate the flash size in the core. The use in swp.c might be
converted to use the (largest) flash erase size. For now, we just
locally calculate the sector size.

Simplify the flash_info database and set the size of the flash directly.
This also let us use the SZ_x macros.

Verified that there's no flash that specifies BP and sector size of zero
to make sure we avoid a division by zero in
spi_nor_get_min_prot_length_sr(). We'll protect from a possible division
by zero in a further patch by introducing a default value for
sector_size.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-5-e60548861b10@kernel.org
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: Avoid setting SRWD bit in SR if WP# signal not connected

Setting the status register write disable (SRWD) bit in the status
register (SR) with WP# signal of the flash left floating or wrongly tied to
GND (that includes internal pull-downs), will configure the SR permanently
as read-only. If WP# signal is left floating or wrongly tied to GND, avoid
setting SRWD bit while writing the SR during flash protection.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20230630142233.63585-3-amit.kumar-mahapatra@amd.com
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: Reorder the preparation vs. locking steps

The ->prepare()/->unprepare() hooks are now legacy, we no longer accept
new drivers supporting them. The only remaining controllers using them
acquires a per-chip mutex, which should not interfere with the rest of
the operation done in the core. As a result, we should be safe to
reorganize these helpers to first perform the preparation, before
acquiring the core locks. This is necessary in order to be able to
improve the locking mechanism in the core (coming next). No side effects
are expected.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230328154105.448540-4-miquel.raynal@bootlin.com
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

mtd: spi-nor: Introduce spi_nor_set_mtd_info()

Used to init all the mtd_info fields. Move the mtd_info init
the last thing in the spi_nor_scan(), so that we avoid superfluous
initialization of the mtd_info fields in case of errors.

While here use common naming scheme for functions that are setting
mtd_info fields:
s/spi_nor_register_locking_ops/spi_nor_set_mtd_locking_ops
s/spi_nor_otp_init/spi_nor_set_mtd_otp_ops
The functions names are self explanatory, get rid of the comment
for the OTP function.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20211207140254.87681-4-tudor.ambarus@microchip.com

mtd: spi-nor: swp: Improve code around spi_nor_check_lock_status_sr()

- bool return value for spi_nor_check_lock_status_sr(), gets rid of
the return 1,
- introduce temporary variables for better readability.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210322075131.45093-3-tudor.ambarus@microchip.com

mtd: spi-nor: Move Software Write Protection logic out of the core

It makes the core file a bit smaller and provides better separation
between the Software Write Protection features and the core logic.
All the next generic software write protection features (e.g. Individual
Block Protection) will reside in swp.c.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20210322075131.45093-2-tudor.ambarus@microchip.com