| /* `struct termios' speed frobnication functions. Linux version. |
| Copyright (C) 1991-2018 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <stddef.h> |
| #include <errno.h> |
| #include <termios.h> |
| |
| |
| /* This is a gross hack around a kernel bug. If the cfsetispeed functions |
| is called with the SPEED argument set to zero this means use the same |
| speed as for output. But we don't have independent input and output |
| speeds and therefore cannot record this. |
| |
| We use an unused bit in the `c_iflag' field to keep track of this |
| use of `cfsetispeed'. The value here must correspond to the one used |
| in `tcsetattr.c'. */ |
| #define IBAUD0 020000000000 |
| |
| |
| /* Return the output baud rate stored in *TERMIOS_P. */ |
| speed_t |
| cfgetospeed (const struct termios *termios_p) |
| { |
| return termios_p->c_cflag & (CBAUD | CBAUDEX); |
| } |
| |
| /* Return the input baud rate stored in *TERMIOS_P. |
| Although for Linux there is no difference between input and output |
| speed, the numerical 0 is a special case for the input baud rate. It |
| should set the input baud rate to the output baud rate. */ |
| speed_t |
| cfgetispeed (const struct termios *termios_p) |
| { |
| return ((termios_p->c_iflag & IBAUD0) |
| ? 0 : termios_p->c_cflag & (CBAUD | CBAUDEX)); |
| } |
| |
| /* Set the output baud rate stored in *TERMIOS_P to SPEED. */ |
| int |
| cfsetospeed (struct termios *termios_p, speed_t speed) |
| { |
| if ((speed & ~CBAUD) != 0 |
| && (speed < B57600 || speed > __MAX_BAUD)) |
| return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); |
| |
| #ifdef _HAVE_STRUCT_TERMIOS_C_OSPEED |
| termios_p->c_ospeed = speed; |
| #endif |
| termios_p->c_cflag &= ~(CBAUD | CBAUDEX); |
| termios_p->c_cflag |= speed; |
| |
| return 0; |
| } |
| libc_hidden_def (cfsetospeed) |
| |
| |
| /* Set the input baud rate stored in *TERMIOS_P to SPEED. |
| Although for Linux there is no difference between input and output |
| speed, the numerical 0 is a special case for the input baud rate. It |
| should set the input baud rate to the output baud rate. */ |
| int |
| cfsetispeed (struct termios *termios_p, speed_t speed) |
| { |
| if ((speed & ~CBAUD) != 0 |
| && (speed < B57600 || speed > __MAX_BAUD)) |
| return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); |
| |
| #ifdef _HAVE_STRUCT_TERMIOS_C_ISPEED |
| termios_p->c_ispeed = speed; |
| #endif |
| if (speed == 0) |
| termios_p->c_iflag |= IBAUD0; |
| else |
| { |
| termios_p->c_iflag &= ~IBAUD0; |
| termios_p->c_cflag &= ~(CBAUD | CBAUDEX); |
| termios_p->c_cflag |= speed; |
| } |
| |
| return 0; |
| } |
| libc_hidden_def (cfsetispeed) |