1 /* vi: set sw=4 ts=4: */
3 * compact speed_t <-> speed functions for busybox
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
13 #if defined __FreeBSD__ \
14 || (defined B115200 && B115200 > 0xffff) \
15 || (defined B230400 && B230400 > 0xffff) \
16 || (defined B460800 && B460800 > 0xffff) \
17 || (defined B921600 && B921600 > 0xffff) \
18 || (defined B1152000 && B1152000 > 0xffff) \
19 || (defined B1000000 && B1000000 > 0xffff) \
20 || (defined B2000000 && B2000000 > 0xffff) \
21 || (defined B3000000 && B3000000 > 0xffff) \
22 || (defined B4000000 && B4000000 > 0xffff)
23 /* On FreeBSD, B<num> constants don't fit into a short */
31 /* On Linux, Bxx constants are 0..15 (up to B38400) and 0x1001..0x100f */
32 static const struct speed_map speeds[] = {
53 /* 38400 = 0x9600, this value would use bit#15 if not "/200" encoded: */
55 {B38400, 38400/200 + 0x8000u},
57 {EXTB, 38400/200 + 0x8000u},
60 {B57600, 57600/200 + 0x8000u},
63 {B115200, 115200/200 + 0x8000u},
66 {B230400, 230400/200 + 0x8000u},
69 {B460800, 460800/200 + 0x8000u},
72 {B576000, 576000/200 + 0x8000u},
75 {B921600, 921600/200 + 0x8000u},
78 {B1152000, 1152000/200 + 0x8000u},
82 {B500000, 500000/200 + 0x8000u},
85 {B1000000, 1000000/200 + 0x8000u},
88 {B1500000, 1500000/200 + 0x8000u},
91 {B2000000, 2000000/200 + 0x8000u},
94 {B2500000, 2500000/200 + 0x8000u},
97 {B3000000, 3000000/200 + 0x8000u},
100 {B3500000, 3500000/200 + 0x8000u},
103 {B4000000, 4000000/200 + 0x8000u},
105 /* 4000000/200 = 0x4e20, bit#15 still does not interfere with the value */
106 /* (can use /800 if higher speeds would appear, /1600 won't work for B500000) */
110 * TODO: maybe we can just bite the bullet, ditch the table and use termios2
111 * Linux API (supports arbitrary baud rates, no Bxxxx mess needed)? Example:
113 * #include <asm/termios.h>
114 * #include <asm/ioctls.h>
116 * ioctl(fd, TCGETS2, &t);
117 * t.c_ospeed = t.c_ispeed = 543210;
118 * t.c_cflag &= ~CBAUD;
119 * t.c_cflag |= BOTHER;
120 * ioctl(fd, TCSETS2, &t);
123 enum { NUM_SPEEDS = ARRAY_SIZE(speeds) };
125 unsigned FAST_FUNC tty_baud_to_value(speed_t speed)
130 if (speed == speeds[i].speed) {
131 if (speeds[i].value & 0x8000u) {
132 return ((unsigned)(speeds[i].value) & 0x7fffU) * 200;
134 return speeds[i].value;
136 } while (++i < NUM_SPEEDS);
141 speed_t FAST_FUNC tty_value_to_baud(unsigned int value)
146 if (value == tty_baud_to_value(speeds[i].speed)) {
147 return speeds[i].speed;
149 } while (++i < NUM_SPEEDS);
151 return (speed_t) - 1;
163 for (v = 0 ; v < 1000000; v++) {
164 s = tty_value_to_baud(v);
165 if (s == (speed_t) -1) {
168 printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
171 printf("-------------------------------\n");
173 for (s = 0 ; s < 010017+1; s++) {
174 v = tty_baud_to_value(s);
178 printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);