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Diffstat (limited to 'tools/termios_linux.h')
| -rw-r--r-- | tools/termios_linux.h | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/tools/termios_linux.h b/tools/termios_linux.h new file mode 100644 index 0000000..d73989b --- /dev/null +++ b/tools/termios_linux.h @@ -0,0 +1,189 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * termios fuctions to support arbitrary baudrates (on Linux) + * + * Copyright (c) 2021 Pali Rohár <pali@kernel.org> + * Copyright (c) 2021 Marek Behún <marek.behun@nic.cz> + */ + +#ifndef _TERMIOS_LINUX_H_ +#define _TERMIOS_LINUX_H_ + +/* + * We need to use raw TCGETS2/TCSETS2 or TCGETS/TCSETS ioctls with the BOTHER + * flag in struct termios2/termios, defined in Linux headers <asm/ioctls.h> + * (included by <sys/ioctl.h>) and <asm/termbits.h>. Since these headers + * conflict with glibc's header file <termios.h>, it is not possible to use + * libc's termios functions and we need to reimplement them via ioctl() calls. + * + * An arbitrary baudrate is supported when the macro BOTHER is defined. The + * baudrate value itself is then stored into the c_ospeed and c_ispeed members. + * If ioctls TCGETS2/TCSETS2 are defined and supported then these fields are + * present in struct termios2, otherwise these fields are present in struct + * termios. + * + * Note that the Bnnn constants from <termios.h> need not be compatible with Bnnn + * constants from <asm/termbits.h>. + */ + +#include <errno.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <asm/termbits.h> + +#if defined(BOTHER) && defined(TCGETS2) +#define termios termios2 +#endif + +static inline int tcgetattr(int fd, struct termios *t) +{ +#if defined(BOTHER) && defined(TCGETS2) + return ioctl(fd, TCGETS2, t); +#else + return ioctl(fd, TCGETS, t); +#endif +} + +static inline int tcsetattr(int fd, int a, const struct termios *t) +{ + int cmd; + + switch (a) { +#if defined(BOTHER) && defined(TCGETS2) + case TCSANOW: + cmd = TCSETS2; + break; + case TCSADRAIN: + cmd = TCSETSW2; + break; + case TCSAFLUSH: + cmd = TCSETSF2; + break; +#else + case TCSANOW: + cmd = TCSETS; + break; + case TCSADRAIN: + cmd = TCSETSW; + break; + case TCSAFLUSH: + cmd = TCSETSF; + break; +#endif + default: + errno = EINVAL; + return -1; + } + + return ioctl(fd, cmd, t); +} + +static inline int tcdrain(int fd) +{ + return ioctl(fd, TCSBRK, 1); +} + +static inline int tcflush(int fd, int q) +{ + return ioctl(fd, TCFLSH, q); +} + +static inline int tcsendbreak(int fd, int d) +{ + return ioctl(fd, TCSBRK, d); +} + +static inline int tcflow(int fd, int a) +{ + return ioctl(fd, TCXONC, a); +} + +static inline pid_t tcgetsid(int fd) +{ + pid_t sid; + + if (ioctl(fd, TIOCGSID, &sid) < 0) + return (pid_t)-1; + + return sid; +} + +static inline speed_t cfgetospeed(const struct termios *t) +{ + return t->c_cflag & CBAUD; +} + +static inline int cfsetospeed(struct termios *t, speed_t s) +{ + if (s & ~CBAUD) { + errno = EINVAL; + return -1; + } + + t->c_cflag &= ~CBAUD; + t->c_cflag |= s; + + return 0; +} + +#ifdef IBSHIFT +static inline speed_t cfgetispeed(const struct termios *t) +{ + speed_t s = (t->c_cflag >> IBSHIFT) & CBAUD; + + if (s == B0) + return cfgetospeed(t); + else + return s; +} + +static inline int cfsetispeed(struct termios *t, speed_t s) +{ + if (s == 0) + s = B0; + + if (s & ~CBAUD) { + errno = EINVAL; + return -1; + } + + t->c_cflag &= ~(CBAUD << IBSHIFT); + t->c_cflag |= s << IBSHIFT; + + return 0; +} +#else /* !IBSHIFT */ +static inline speed_t cfgetispeed(const struct termios *t) +{ + return cfgetospeed(t); +} + +static inline int cfsetispeed(struct termios *t, speed_t s) +{ + return cfsetospeed(t, s); +} +#endif /* !IBSHIFT */ + +static inline int cfsetspeed(struct termios *t, speed_t s) +{ + if (cfsetospeed(t, s)) + return -1; +#ifdef IBSHIFT + if (cfsetispeed(t, s)) + return -1; +#endif + + return 0; +} + +static void cfmakeraw(struct termios *t) +{ + t->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | + ICRNL | IXON); + t->c_oflag &= ~OPOST; + t->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN); + t->c_cflag &= ~(CSIZE | PARENB); + t->c_cflag |= CS8; +} + +#endif /* _TERMIOS_LINUX_H_ */ |