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1.. SPDX-License-Identifier: GPL-2.02 3.. _GPIO_V2_LINE_GET_VALUES_IOCTL:4 5*****************************6GPIO_V2_LINE_GET_VALUES_IOCTL7*****************************8 9Name10====11 12GPIO_V2_LINE_GET_VALUES_IOCTL - Get the values of requested lines.13 14Synopsis15========16 17.. c:macro:: GPIO_V2_LINE_GET_VALUES_IOCTL18 19``int ioctl(int req_fd, GPIO_V2_LINE_GET_VALUES_IOCTL, struct gpio_v2_line_values *values)``20 21Arguments22=========23 24``req_fd``25 The file descriptor of the GPIO character device, as returned in the26 :c:type:`request.fd<gpio_v2_line_request>` by gpio-v2-get-line-ioctl.rst.27 28``values``29 The :c:type:`line_values<gpio_v2_line_values>` to get with the ``mask`` set30 to indicate the subset of requested lines to get.31 32Description33===========34 35Get the values of requested lines.36 37The values returned are logical, indicating if the line is active or inactive.38The ``GPIO_V2_LINE_FLAG_ACTIVE_LOW`` flag controls the mapping between physical39values (high/low) and logical values (active/inactive).40If ``GPIO_V2_LINE_FLAG_ACTIVE_LOW`` is not set then high is active and low is41inactive. If ``GPIO_V2_LINE_FLAG_ACTIVE_LOW`` is set then low is active and42high is inactive.43 44The values of both input and output lines may be read.45 46For output lines, the value returned is driver and configuration dependent and47may be either the output buffer (the last requested value set) or the input48buffer (the actual level of the line), and depending on the hardware and49configuration these may differ.50 51Return Value52============53 54On success 0 and the corresponding :c:type:`values.bits<gpio_v2_line_values>`55contain the value read.56 57On error -1 and the ``errno`` variable is set appropriately.58Common error codes are described in error-codes.rst.59