From e54def4ad8144ab15f826416e2e0f290ef1901b4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 19 Jun 2024 23:00:30 +0200 Subject: Adding upstream version 6.9.2. Signed-off-by: Daniel Baumann --- .../gpio/gpio-handle-get-line-values-ioctl.rst | 56 ++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 Documentation/userspace-api/gpio/gpio-handle-get-line-values-ioctl.rst (limited to 'Documentation/userspace-api/gpio/gpio-handle-get-line-values-ioctl.rst') 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 0000000000..25263b8f05 --- /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` by gpio-get-linehandle-ioctl.rst. + +``values`` + The :c:type:`line_values` 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. -- cgit v1.2.3