tools: gpio-utils: fix various kernel-doc warnings

Fix several problems in kernel-doc notation in gpio-utils.c.

gpio-utils.c:37: warning: Incorrect use of kernel-doc format: * gpiotools_request_line() - request gpio lines in a gpiochip
gpio-utils.c:61: warning: expecting prototype for doc(). Prototype was for gpiotools_request_line() instead
gpio-utils.c:265: warning: Excess function parameter 'value' description in 'gpiotools_sets'
gpio-utils.c:1: warning: 'gpiotools_request_lines' not found

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

tools: gpio: remove uAPI v1 code no longer used by selftests

gpio-mockup-chardev helper has been obsoleted and removed, so also remove
the tools/gpio code that it, and nothing else, was using.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

tools: gpio: port gpio-hammer to v2 uAPI

Port the gpio-hammer tool to the latest GPIO uAPI.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

tools: gpio: rename nlines to num_lines

Rename nlines to num_lines to be consistent with other usage for fields
describing the number of entries in an array.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

tools: gpio: fix spurious close warning in gpio-utils

Fix bogus close warning that occurs when opening the character device
fails.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

tools: gpio: Fix typo in gpio-utils

Replace COMSUMER with proper CONSUMER

Signed-off-by: Mykyta Poturai <mykyta.poturai@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools: gpio: Print error string on IOCTL failures

Add to error messages the error description by concatenating
output of strerror() function to error messages print out by
gpio-utils.c on IOCTL failures.
Rationalize error messages, while at there, making all of them
look the same.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

tools/gpio: add gpio basic opereations

Add basic gpio operations. User could get/set gpio value for specific
line of gpiochip.

Reference "tools/gpio/gpio-hammer.c" or
"tools/testing/selftest/gpio/gpio-mockup-chardev.c" for how to use it.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Reviewed-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

tools/gpio: create GPIO tools

This creates GPIO tools under tools/gpio/* and adds a single
example program to list the GPIOs on a system. When proper
devices are created it provides this minimal output:

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>