bus: ts-nbus: Improve error reporting

Using dev_err_probe() brings several improvements:

- emits the symbolic error code
- properly handles EPROBE_DEFER
- combines error message generation and return value handling

While at it add error messages to two error paths that were silent
before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

bus: ts-nbus: Convert to atomic pwm API

With this change the PWM hardware is only configured once (instead of
three times).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

bus: ts-nbus: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/r/20231109202830.4124591-13-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 2)

Based on the normalized pattern:

this file is licensed under the terms of the gnu general public
license version 2 this program is licensed as is without any warranty
of any kind whether express or implied

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpiolib: Pass array info to get/set array functions

In order to make use of array info obtained from gpiod_get_array() and
speed up processing of arrays matching single GPIO chip layout, that
information must be passed to get/set array functions. Extend the
functions' API with that additional parameter and update all users.
Pass NULL if a user builds an array itself from single GPIOs.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rojhalat Ibrahim <imr@rtschenk.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Pass bitmaps, not integer arrays, to get/set array

Most users of get/set array functions iterate consecutive bits of data,
usually a single integer, while processing array of results obtained
from, or building an array of values to be passed to those functions.
Save time wasted on those iterations by changing the functions' API to
accept bitmaps.

All current users are updated as well.

More benefits from the change are expected as soon as planned support
for accepting/passing those bitmaps directly from/to respective GPIO
chip callbacks if applicable is implemented.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Cc: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rojhalat Ibrahim <imr@rtschenk.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

bus: add driver for the Technologic Systems NBUS

This driver implements a GPIOs bit-banged bus, called the NBUS by
Technologic Systems. It is used to communicate with the peripherals in
the FPGA on the TS-4600 SoM.

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>