treewide, serdev: change receive_buf() return type to size_t

receive_buf() is called from ttyport_receive_buf() that expects values
">= 0" from serdev_controller_receive_buf(), change its return type from
ssize_t to size_t.

The need for this clean-up was noticed while fixing a warning, see
commit 94d053942544 ("Bluetooth: btnxpuart: fix recv_buf() return value").
Changing the callback prototype to return an unsigned seems the best way
to document the API and ensure that is properly used.

GNSS drivers implementation of serdev receive_buf() callback return
directly the return value of gnss_insert_raw(). gnss_insert_raw()
returns a signed int, however this is not an issue since the value
returned is always positive, because of the kfifo_in() implementation.
gnss_insert_raw() could be changed to return also an unsigned, however
this is not implemented here as request by the GNSS maintainer Johan
Hovold.

Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio
Reviewed-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Acked-by: Maximilian Luz <luzmaximilian@gmail.com> # for platform/surface
Acked-by: Lee Jones <lee@kernel.org>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240122180551.34429-1-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mfd: rave-sp: Avoid unnecessary use of comma operator

Although it does not seem to have any untoward side-effects,
the use of ';' to separate to assignments seems more appropriate than ','.

Flagged by clang-17 -Wcomma

No functional change intended. Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240123-rave-sp-comma-v1-1-84e9b15ba205@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

tty: serdev: convert to u8 and size_t

Switch character types to u8 and sizes to size_t. To conform to
characters/sizes in the rest of the tty layer.

This patch converts struct serdev_device_ops hooks and its
instantiations.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20231206073712.17776-24-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lib: crc_ccitt_false() is identical to crc_itu_t()

crc_ccitt_false() was introduced in commit 0d85adb5fbd33 ("lib/crc-ccitt:
Add CCITT-FALSE CRC16 variant"), but it is redundant with crc_itu_t().
Since the latter is more used, it is the one being kept.

Link: https://lkml.kernel.org/r/20231219131154.748577-1-Mathis.Marion@silabs.com
Signed-off-by: Mathis Marion <mathis.marion@silabs.com>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>
Cc: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mfd: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174731.4059811-1-robh@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

mfd: rave-sp: Fix mistake in 'struct rave_sp_deframer's kerneldoc

Argument 'received' was incorrectly named by its struct type 'completion'
instead of its name.

Fixes the following W=1 warning:

drivers/mfd/rave-sp.c:107: warning: Function parameter or member 'received' not described in 'rave_sp_reply'

Cc: Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>
Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Fix typo in rave_sp_checksum comment

Caculated -> Calculated

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Emulate CMD_GET_STATUS on device that don't support it

CMD_GET_STATUS is not supported by some devices implementing
RDU2-compatible ICD as well as "legacy" devices. To account for that
fact, add code that obtains the same information (app/bootloader FW
version) using several different commands.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Add legacy watchdog ping command translation

This is needed to make rave-sp-wdt driver to properly ping the
watchdog on "legacy" firmware.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Add legacy EEPROM access command translation

This is needed to make rave-sp-eeprom driver work on "legacy"
firmware.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Initialize flow control and parity of the port

Relying on serial port defaults for flow control and parity can result
in complete breakdown of communication with RAVE SP on some platforms
where defaults are not what we need them to be. One such case is
VF610-base ZII SPU3 board (not supported upstream). To avoid this
problem in the future, add code to explicitly configure both.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Fix incorrectly specified checksum type

RAVE SP firmware covered by "legacy" variant uses 16-bit CCITT
checksum algorithm. Change the code to correctly reflect that.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Remove unused defines

Remove unusded defines that are a leftover from earlier iterations of
the driver.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Remove VLA

As part of the effort to remove VLAs from the kernel[1], this creates
constants for the checksum lengths of CCITT and 8B2C and changes
crc_calculated to be the maximum size of a checksum.

https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Kyle Spiers <ksspiers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Check received frame length before accepting next byte

Check received frame length _before_ accepting next byte in order to
avoid incorrectly rejecting payloads that are RAVE_SP_RX_BUFFER_SIZE
long.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Convert print_hex_dump() to print_hex_dump_debug()

Convert print_hex_dump() to print_hex_dump_debug() to be able to
leverage CONFIG_DYNAMIC_DEBUG.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: rave-sp: Add code to print firmware versions

Add code that would query and print out bootloader and application
firmware version info.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

mfd: Add driver for RAVE Supervisory Processor

Add a driver for RAVE Supervisory Processor, an MCU implementing
various bits of housekeeping functionality (watchdoging, backlight
control, LED control, etc) on RAVE family of products by Zodiac
Inflight Innovations.

This driver implementes core MFD/serdev device as well as
communication subroutines necessary for commanding the device.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>