Pali Rohár | fd935e9 | 2021-09-24 23:07:06 +0200 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
| 2 | /* |
| 3 | * termios fuctions to support arbitrary baudrates (on Linux) |
| 4 | * |
| 5 | * Copyright (c) 2021 Pali Rohár <pali@kernel.org> |
Marek Behún | d63726e | 2022-06-01 17:17:06 +0200 | [diff] [blame] | 6 | * Copyright (c) 2021 Marek Behún <kabel@kernel.org> |
Pali Rohár | fd935e9 | 2021-09-24 23:07:06 +0200 | [diff] [blame] | 7 | */ |
| 8 | |
| 9 | #ifndef _TERMIOS_LINUX_H_ |
| 10 | #define _TERMIOS_LINUX_H_ |
| 11 | |
| 12 | /* |
| 13 | * We need to use raw TCGETS2/TCSETS2 or TCGETS/TCSETS ioctls with the BOTHER |
| 14 | * flag in struct termios2/termios, defined in Linux headers <asm/ioctls.h> |
| 15 | * (included by <sys/ioctl.h>) and <asm/termbits.h>. Since these headers |
| 16 | * conflict with glibc's header file <termios.h>, it is not possible to use |
| 17 | * libc's termios functions and we need to reimplement them via ioctl() calls. |
| 18 | * |
| 19 | * An arbitrary baudrate is supported when the macro BOTHER is defined. The |
| 20 | * baudrate value itself is then stored into the c_ospeed and c_ispeed members. |
| 21 | * If ioctls TCGETS2/TCSETS2 are defined and supported then these fields are |
| 22 | * present in struct termios2, otherwise these fields are present in struct |
| 23 | * termios. |
| 24 | * |
| 25 | * Note that the Bnnn constants from <termios.h> need not be compatible with Bnnn |
| 26 | * constants from <asm/termbits.h>. |
| 27 | */ |
| 28 | |
| 29 | #include <errno.h> |
| 30 | #include <sys/ioctl.h> |
| 31 | #include <sys/types.h> |
| 32 | #include <asm/termbits.h> |
| 33 | |
| 34 | #if defined(BOTHER) && defined(TCGETS2) |
| 35 | #define termios termios2 |
| 36 | #endif |
| 37 | |
| 38 | static inline int tcgetattr(int fd, struct termios *t) |
| 39 | { |
| 40 | #if defined(BOTHER) && defined(TCGETS2) |
| 41 | return ioctl(fd, TCGETS2, t); |
| 42 | #else |
| 43 | return ioctl(fd, TCGETS, t); |
| 44 | #endif |
| 45 | } |
| 46 | |
| 47 | static inline int tcsetattr(int fd, int a, const struct termios *t) |
| 48 | { |
| 49 | int cmd; |
| 50 | |
| 51 | switch (a) { |
| 52 | #if defined(BOTHER) && defined(TCGETS2) |
| 53 | case TCSANOW: |
| 54 | cmd = TCSETS2; |
| 55 | break; |
| 56 | case TCSADRAIN: |
| 57 | cmd = TCSETSW2; |
| 58 | break; |
| 59 | case TCSAFLUSH: |
| 60 | cmd = TCSETSF2; |
| 61 | break; |
| 62 | #else |
| 63 | case TCSANOW: |
| 64 | cmd = TCSETS; |
| 65 | break; |
| 66 | case TCSADRAIN: |
| 67 | cmd = TCSETSW; |
| 68 | break; |
| 69 | case TCSAFLUSH: |
| 70 | cmd = TCSETSF; |
| 71 | break; |
| 72 | #endif |
| 73 | default: |
| 74 | errno = EINVAL; |
| 75 | return -1; |
| 76 | } |
| 77 | |
| 78 | return ioctl(fd, cmd, t); |
| 79 | } |
| 80 | |
| 81 | static inline int tcdrain(int fd) |
| 82 | { |
| 83 | return ioctl(fd, TCSBRK, 1); |
| 84 | } |
| 85 | |
| 86 | static inline int tcflush(int fd, int q) |
| 87 | { |
| 88 | return ioctl(fd, TCFLSH, q); |
| 89 | } |
| 90 | |
| 91 | static inline int tcsendbreak(int fd, int d) |
| 92 | { |
Pali Rohár | b74a201 | 2021-10-06 14:30:25 +0200 | [diff] [blame] | 93 | #ifdef TCSBRKP |
| 94 | return ioctl(fd, TCSBRKP, d); |
| 95 | #else |
| 96 | return ioctl(fd, TCSBRK, 0); |
| 97 | #endif |
Pali Rohár | fd935e9 | 2021-09-24 23:07:06 +0200 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | static inline int tcflow(int fd, int a) |
| 101 | { |
| 102 | return ioctl(fd, TCXONC, a); |
| 103 | } |
| 104 | |
| 105 | static inline pid_t tcgetsid(int fd) |
| 106 | { |
| 107 | pid_t sid; |
| 108 | |
| 109 | if (ioctl(fd, TIOCGSID, &sid) < 0) |
| 110 | return (pid_t)-1; |
| 111 | |
| 112 | return sid; |
| 113 | } |
| 114 | |
| 115 | static inline speed_t cfgetospeed(const struct termios *t) |
| 116 | { |
| 117 | return t->c_cflag & CBAUD; |
| 118 | } |
| 119 | |
| 120 | static inline int cfsetospeed(struct termios *t, speed_t s) |
| 121 | { |
| 122 | if (s & ~CBAUD) { |
| 123 | errno = EINVAL; |
| 124 | return -1; |
| 125 | } |
| 126 | |
| 127 | t->c_cflag &= ~CBAUD; |
| 128 | t->c_cflag |= s; |
| 129 | |
| 130 | return 0; |
| 131 | } |
| 132 | |
| 133 | #ifdef IBSHIFT |
| 134 | static inline speed_t cfgetispeed(const struct termios *t) |
| 135 | { |
| 136 | speed_t s = (t->c_cflag >> IBSHIFT) & CBAUD; |
| 137 | |
| 138 | if (s == B0) |
| 139 | return cfgetospeed(t); |
| 140 | else |
| 141 | return s; |
| 142 | } |
| 143 | |
| 144 | static inline int cfsetispeed(struct termios *t, speed_t s) |
| 145 | { |
| 146 | if (s == 0) |
| 147 | s = B0; |
| 148 | |
| 149 | if (s & ~CBAUD) { |
| 150 | errno = EINVAL; |
| 151 | return -1; |
| 152 | } |
| 153 | |
| 154 | t->c_cflag &= ~(CBAUD << IBSHIFT); |
| 155 | t->c_cflag |= s << IBSHIFT; |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | #else /* !IBSHIFT */ |
| 160 | static inline speed_t cfgetispeed(const struct termios *t) |
| 161 | { |
| 162 | return cfgetospeed(t); |
| 163 | } |
| 164 | |
| 165 | static inline int cfsetispeed(struct termios *t, speed_t s) |
| 166 | { |
| 167 | return cfsetospeed(t, s); |
| 168 | } |
| 169 | #endif /* !IBSHIFT */ |
| 170 | |
| 171 | static inline int cfsetspeed(struct termios *t, speed_t s) |
| 172 | { |
| 173 | if (cfsetospeed(t, s)) |
| 174 | return -1; |
| 175 | #ifdef IBSHIFT |
| 176 | if (cfsetispeed(t, s)) |
| 177 | return -1; |
| 178 | #endif |
| 179 | |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | static void cfmakeraw(struct termios *t) |
| 184 | { |
| 185 | t->c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | |
| 186 | ICRNL | IXON); |
| 187 | t->c_oflag &= ~OPOST; |
| 188 | t->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN); |
| 189 | t->c_cflag &= ~(CSIZE | PARENB); |
| 190 | t->c_cflag |= CS8; |
| 191 | } |
| 192 | |
| 193 | #endif /* _TERMIOS_LINUX_H_ */ |