tools: gpio: fix debounce_period_us output of lsgpio

Fix incorrect output that could occur when more attributes are used and
GPIO_V2_LINE_ATTR_ID_DEBOUNCE is not the first one.

Signed-off-by: Milo Spadacini <milo.spadacini@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

tools: gpio: add support for reporting realtime event clock to lsgpio

Add support for reporting if a line is configured to report realtime
timestamps in events.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20201014231158.34117-3-warthog618@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

tools: gpio: port lsgpio to v2 uAPI

Port the lsgpio 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: fix spurious close warning in lsgpio

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: add bias flags to lsgpio

Add display of the bias flags.

Signed-off-by: Kent Gibson <warthog618@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: Add missing initialization of device_name

lsgpio.c: In function ‘main’:
lsgpio.c:166:7: warning: ‘device_name’ may be used uninitialized in this functio
n [-Wmaybe-uninitialized]
ret = list_device(device_name);
^

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: present the consumer of a line to userspace

I named the field representing the current user of GPIO line as
"label" but this is too vague and ambiguous. Before anyone gets
confused, rename it to "consumer" and indicate clearly in the
documentation that this is a string set by the user of the line.

Also clean up leftovers in the documentation.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

tools: gpio: Small updates for output format

Use %2d for the GPIO line number. This should align the results
horziontally for most gpio chips.

The GPIO label uses quotes for real values. For GPIO names this is
currently missing. The patch adds the missing quote.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: add userspace ABI for GPIO line information

This adds a GPIO line ABI for getting name, label and a few select
flags from the kernel.

This hides the kernel internals and only tells userspace what it
may need to know: the different in-kernel consumers are masked
behind the flag "kernel" and that is all userspace needs to know.

However electric characteristics like active low, open drain etc
are reflected to userspace, as this is important information.

We provide information on all lines on all chips, later on we will
likely add a flag for the chardev consumer so we can filter and
display only the lines userspace actually uses in e.g. lsgpio,
but then we first need an ABI for userspace to grab and use
(get/set/select direction) a GPIO line.

Sample output from "lsgpio" on ux500:

GPIO chip: gpiochip7, "8011e000.gpio", 32 GPIO lines
line 0: unnamed unlabeled
line 1: unnamed unlabeled
(...)
line 25: unnamed "SFH7741 Proximity Sensor" [kernel output open-drain]
line 26: unnamed unlabeled
(...)

Tested-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: store reflect the label to userspace

The gpio_chip label is useful for userspace to understand what
kind of GPIO chip it is dealing with. Let's store a copy of this
label in the gpio_device, add it to the struct passed to userspace
for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it.

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>