kernel/drivers/tty/serial/serial_mctrl_gpio.h, branch linux-4.1.y Hosts the 0x221E linux distro kernel. https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-4.1.y 2014-05-28T19:49:14Z tty/serial: Add GPIOLIB helpers for controlling modem lines 2014-05-28T19:49:14Z Richard Genoud richard.genoud@gmail.com 2014-05-13T18:20:43Z urn:sha1:84130aace83989c1dba073ed98dad721d2060258 This patch add some helpers to control modem lines (CTS/RTS/DSR...) via GPIO. This will be useful for many boards which have a serial controller that only handle CTS/RTS pins (or even just RX/TX). Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tested-by: Yegor Yefremov <yegorslists@googlemail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>