// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/termios.h> #include <linux/tty.h> #include <linux/export.h> #include "tty.h" /* * Routine which returns the baud rate of the tty * * Note that the baud_table needs to be kept in sync with the * include/asm/termbits.h file. */ static const speed_t baud_table[] = …; static const tcflag_t baud_bits[] = …; static int n_baud_table = …; /** * tty_termios_baud_rate * @termios: termios structure * * Convert termios baud rate data into a speed. This should be called * with the termios lock held if this termios is a terminal termios * structure. Device drivers can call this function but should use * ->c_[io]speed directly as they are updated. * * Locking: none */ speed_t tty_termios_baud_rate(const struct ktermios *termios) { … } EXPORT_SYMBOL(…); /** * tty_termios_input_baud_rate * @termios: termios structure * * Convert termios baud rate data into a speed. This should be called * with the termios lock held if this termios is a terminal termios * structure. Device drivers can call this function but should use * ->c_[io]speed directly as they are updated. * * Locking: none */ speed_t tty_termios_input_baud_rate(const struct ktermios *termios) { … } EXPORT_SYMBOL(…); /** * tty_termios_encode_baud_rate * @termios: ktermios structure holding user requested state * @ibaud: input speed * @obaud: output speed * * Encode the speeds set into the passed termios structure. This is * used as a library helper for drivers so that they can report back * the actual speed selected when it differs from the speed requested * * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour * we need to carefully set the bits when the user does not get the * desired speed. We allow small margins and preserve as much of possible * of the input intent to keep compatibility. * * Locking: Caller should hold termios lock. This is already held * when calling this function from the driver termios handler. * * The ifdefs deal with platforms whose owners have yet to update them * and will all go away once this is done. */ void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud) { … } EXPORT_SYMBOL_GPL(…); /** * tty_encode_baud_rate - set baud rate of the tty * @tty: terminal device * @ibaud: input baud rate * @obaud: output baud rate * * Update the current termios data for the tty with the new speed * settings. The caller must hold the termios_rwsem for the tty in * question. */ void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud) { … } EXPORT_SYMBOL_GPL(…);
Codebase Browser
linux