1 files changed, 56 insertions, 0 deletions
diff --git a/Documentation/userspace-api/gpio/gpio-handle-get-line-values-ioctl.rst b/Documentation/userspace-api/gpio/gpio-handle-get-line-values-ioctl.rst
new file mode 100644
index 0000000000000..25263b8f05888
--- /dev/null
+++ b/Documentation/userspace-api/gpio/gpio-handle-get-line-values-ioctl.rst
@@ -0,0 +1,56 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _GPIOHANDLE_GET_LINE_VALUES_IOCTL:
+
+********************************
+GPIOHANDLE_GET_LINE_VALUES_IOCTL
+********************************
+.. warning::
+    This ioctl is part of chardev_v1.rst and is obsoleted by
+    gpio-v2-line-get-values-ioctl.rst.
+
+Name
+====
+
+GPIOHANDLE_GET_LINE_VALUES_IOCTL - Get the values of all requested lines.
+
+Synopsis
+========
+
+.. c:macro:: GPIOHANDLE_GET_LINE_VALUES_IOCTL
+
+``int ioctl(int handle_fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, struct gpiohandle_data *values)``
+
+Arguments
+=========
+
+``handle_fd``
+    The file descriptor of the GPIO character device, as returned in the
+    :c:type:`request.fd<gpiohandle_request>` by gpio-get-linehandle-ioctl.rst.
+
+``values``
+    The :c:type:`line_values<gpiohandle_data>` to be populated.
+
+Description
+===========
+
+Get the values of all requested lines.
+
+The values of both input and output lines may be read.
+
+For output lines, the value returned is driver and configuration dependent and
+may be either the output buffer (the last requested value set) or the input
+buffer (the actual level of the line), and depending on the hardware and
+configuration these may differ.
+
+This ioctl can also be used to read the line value for line events,
+substituting the ``event_fd`` for the ``handle_fd``.  As there is only
+one line requested in that case, only the one value is returned in ``values``.
+
+Return Value
+============
+
+On success 0 and ``values`` populated with the values read.
+
+On error -1 and the ``errno`` variable is set appropriately.
+Common error codes are described in error-codes.rst.