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1.. SPDX-License-Identifier: GPL-2.02 3.. _GPIO_V2_LINE_SET_CONFIG_IOCTL:4 5*****************************6GPIO_V2_LINE_SET_CONFIG_IOCTL7*****************************8 9Name10====11 12GPIO_V2_LINE_SET_CONFIG_IOCTL - Update the configuration of previously requested lines.13 14Synopsis15========16 17.. c:macro:: GPIO_V2_LINE_SET_CONFIG_IOCTL18 19``int ioctl(int req_fd, GPIO_V2_LINE_SET_CONFIG_IOCTL, struct gpio_v2_line_config *config)``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``config``29 The new :c:type:`configuration<gpio_v2_line_config>` to apply to the30 requested lines.31 32Description33===========34 35Update the configuration of previously requested lines, without releasing the36line or introducing potential glitches.37 38The new configuration must specify a configuration for all requested lines.39 40The same :ref:`gpio-v2-get-line-config-rules` and41:ref:`gpio-v2-get-line-config-support` that apply when requesting the lines42also apply when updating the line configuration, with the additional43restriction that a direction flag must be set to enable reconfiguration.44If no direction flag is set in the configuration for a given line then the45configuration for that line is left unchanged.46 47The motivating use case for this command is changing direction of48bi-directional lines between input and output, but it may also be used to49dynamically control edge detection, or more generally move lines seamlessly50from one configuration state to another.51 52To only change the value of output lines, use53gpio-v2-line-set-values-ioctl.rst.54 55Return Value56============57 58On success 0.59 60On error -1 and the ``errno`` variable is set appropriately.61Common error codes are described in error-codes.rst.62