Lines Matching +full:gpio +full:- +full:line

1 .. SPDX-License-Identifier: GPL-2.0
4 GPIO Character Device Userspace API
8 ``include/uapi/linux/gpio.h.``
18    Read Documentation/driver-api/gpio/drivers-on-gpio.rst to avoid reinventing
21    Similarly, for multi-function lines there may be other subsystems, such as
23    Documentation/driver-api/pwm.rst, Documentation/w1/index.rst etc, that
26 Basic examples using the character device API can be found in ``tools/gpio/*``.
28 The API is based around two major objects, the :ref:`gpio-v2-chip` and the
29 :ref:`gpio-v2-line-request`.
31 .. _gpio-v2-chip:
36 The Chip represents a single GPIO chip and is exposed to userspace using device
39 Each chip supports a number of GPIO lines,
41 ``offset`` in the range from 0 to ``chip.lines - 1``, i.e. `[0,chip.lines)`.
43 Lines are requested from the chip using gpio-v2-get-line-ioctl.rst
44 and the resulting line request is used to access the GPIO chip's lines or
48 on the GPIO device file is referred to as ``chip_fd``.
51 ----------
58    Get Line <gpio-v2-get-line-ioctl>
59    Get Chip Info <gpio-get-chipinfo-ioctl>
60    Get Line Info <gpio-v2-get-lineinfo-ioctl>
61    Watch Line Info <gpio-v2-get-lineinfo-watch-ioctl>
62    Unwatch Line Info <gpio-get-lineinfo-unwatch-ioctl>
63    Read Line Info Changed Events <gpio-v2-lineinfo-changed-read>
65 .. _gpio-v2-line-request:
67 Line Request
70 Line requests are created by gpio-v2-get-line-ioctl.rst and provide
71 access to a set of requested lines.  The line request is exposed to userspace
73 :c:type:`request.fd<gpio_v2_line_request>` by gpio-v2-get-line-ioctl.rst.
75 Within this documentation, the line request file descriptor is referred to
79 ----------
81 The following operations may be performed on the line request:
86    Get Line Values <gpio-v2-line-get-values-ioctl>
87    Set Line Values <gpio-v2-line-set-values-ioctl>
88    Read Line Edge Events <gpio-v2-line-event-read>
89    Reconfigure Lines <gpio-v2-line-set-config-ioctl>
95 as defined in ``include/uapi/linux/gpio.h``.
97 .. kernel-doc:: include/uapi/linux/gpio.h
116    error-codes