1.. SPDX-License-Identifier: GPL-2.0 2 3.. _GPIOHANDLE_GET_LINE_VALUES_IOCTL: 4 5******************************** 6GPIOHANDLE_GET_LINE_VALUES_IOCTL 7******************************** 8.. warning:: 9 This ioctl is part of chardev_v1.rst and is obsoleted by 10 gpio-v2-line-get-values-ioctl.rst. 11 12Name 13==== 14 15GPIOHANDLE_GET_LINE_VALUES_IOCTL - Get the values of all requested lines. 16 17Synopsis 18======== 19 20.. c:macro:: GPIOHANDLE_GET_LINE_VALUES_IOCTL 21 22``int ioctl(int handle_fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, struct gpiohandle_data *values)`` 23 24Arguments 25========= 26 27``handle_fd`` 28 The file descriptor of the GPIO character device, as returned in the 29 :c:type:`request.fd<gpiohandle_request>` by gpio-get-linehandle-ioctl.rst. 30 31``values`` 32 The :c:type:`line_values<gpiohandle_data>` to be populated. 33 34Description 35=========== 36 37Get the values of all requested lines. 38 39The values of both input and output lines may be read. 40 41For output lines, the value returned is driver and configuration dependent and 42may be either the output buffer (the last requested value set) or the input 43buffer (the actual level of the line), and depending on the hardware and 44configuration these may differ. 45 46This ioctl can also be used to read the line value for line events, 47substituting the ``event_fd`` for the ``handle_fd``. As there is only 48one line requested in that case, only the one value is returned in ``values``. 49 50Return Value 51============ 52 53On success 0 and ``values`` populated with the values read. 54 55On error -1 and the ``errno`` variable is set appropriately. 56Common error codes are described in error-codes.rst. 57