mirror of
https://sourceware.org/git/glibc.git
synced 2025-08-08 17:42:12 +03:00
5f138519eb
Add an explicitly numeric interface for baudrate setting. For glibc, this only announces what is a fair accompli, but this is a plausible way forward for standardization, and may be possible to infill on non-compliant systems. The POSIX committee has stated: [https://www.austingroupbugs.net/view.php?id=1916#c7135] A future version of this standard is expected to add at least the following symbolic constants for use as values of objects of type speed_t: B57600, B115200, B230400, B460800, and B921600. Implementations are encouraged to propose additional interfaces which will make it possible to set and query a wider range of speeds than just those enumerated by the constants beginning with B. If a set of common interfaces emerges between several implementations, a future version of this standard will likely add those interfaces. This is exactly that interface. The use of the term "baud" is due to the need to have a term contrasting "speed", and it is already well established as a legacy term -- including in the names of the legacy Bxxx constants. Futhermore, it *is* valid from the point of view that the termios interface fundamentally emulates an RS-232 serial port as far as the application software is concerned. The documentation states that for the current version of glibc, speed_t == baud_t, but explicitly declares that this may not be the case in the future. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
72 lines
2.0 KiB
C
72 lines
2.0 KiB
C
/* `struct termios' speed frobnication functions. 4.4 BSD/generic GNU version.
|
|
Copyright (C) 1991-2025 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <stddef.h>
|
|
#include <errno.h>
|
|
#include <termios.h>
|
|
|
|
/* Return the output baud rate stored in *TERMIOS_P. */
|
|
speed_t
|
|
__cfgetospeed (const struct termios *termios_p)
|
|
{
|
|
return termios_p->__ospeed;
|
|
}
|
|
libc_hidden_def (__cfgetospeed)
|
|
weak_alias (__cfgetospeed, cfgetospeed)
|
|
|
|
/* Return the input baud rate stored in *TERMIOS_P. */
|
|
speed_t
|
|
__cfgetispeed (const struct termios *termios_p)
|
|
{
|
|
return termios_p->__ispeed;
|
|
}
|
|
libc_hidden_def (__cfgetispeed)
|
|
weak_alias (__cfgetispeed, cfgetispeed)
|
|
|
|
/* Set the output baud rate stored in *TERMIOS_P to SPEED. */
|
|
int
|
|
__cfsetospeed (struct termios *termios_p, speed_t speed)
|
|
{
|
|
if (termios_p == NULL)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
termios_p->__ospeed = speed;
|
|
return 0;
|
|
}
|
|
libc_hidden_def (__cfsetospeed)
|
|
weak_alias (__cfsetospeed, cfsetospeed)
|
|
|
|
/* Set the input baud rate stored in *TERMIOS_P to SPEED. */
|
|
int
|
|
__cfsetispeed (struct termios *termios_p, speed_t speed)
|
|
{
|
|
if (termios_p == NULL)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
termios_p->__ispeed = speed;
|
|
return 0;
|
|
}
|
|
libc_hidden_def (__cfsetispeed)
|
|
weak_alias (__cfsetispeed, cfsetispeed)
|