1 /* vi: set sw=4 ts=4: */
2 /*
3 * compact speed_t <-> speed functions for busybox
4 *
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9
10 #include "libbb.h"
11
12 struct speed_map {
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 */
24 unsigned speed;
25 #else
26 unsigned short speed;
27 #endif
28 unsigned short value;
29 };
30
31 /* On Linux, Bxx constants are 0..15 (up to B38400) and 0x1001..0x100f */
32 static const struct speed_map speeds[] = {
33 {B0, 0},
34 {B50, 50},
35 {B75, 75},
36 {B110, 110},
37 {B134, 134},
38 {B150, 150},
39 {B200, 200},
40 {B300, 300},
41 {B600, 600},
42 {B1200, 1200},
43 {B1800, 1800},
44 {B2400, 2400},
45 {B4800, 4800},
46 {B9600, 9600},
47 #ifdef B19200
48 {B19200, 19200},
49 #elif defined(EXTA)
50 {EXTA, 19200},
51 #endif
52 /* 19200 = 0x4b00 */
53 /* 38400 = 0x9600, this value would use bit#15 if not "/200" encoded: */
54 #ifdef B38400
55 {B38400, 38400/200 + 0x8000u},
56 #elif defined(EXTB)
57 {EXTB, 38400/200 + 0x8000u},
58 #endif
59 #ifdef B57600
60 {B57600, 57600/200 + 0x8000u},
61 #endif
62 #ifdef B115200
63 {B115200, 115200/200 + 0x8000u},
64 #endif
65 #ifdef B230400
66 {B230400, 230400/200 + 0x8000u},
67 #endif
68 #ifdef B460800
69 {B460800, 460800/200 + 0x8000u},
70 #endif
71 #ifdef B576000
72 {B576000, 576000/200 + 0x8000u},
73 #endif
74 #ifdef B921600
75 {B921600, 921600/200 + 0x8000u},
76 #endif
77 #ifdef B1152000
78 {B1152000, 1152000/200 + 0x8000u},
79 #endif
80
81 #ifdef B500000
82 {B500000, 500000/200 + 0x8000u},
83 #endif
84 #ifdef B1000000
85 {B1000000, 1000000/200 + 0x8000u},
86 #endif
87 #ifdef B1500000
88 {B1500000, 1500000/200 + 0x8000u},
89 #endif
90 #ifdef B2000000
91 {B2000000, 2000000/200 + 0x8000u},
92 #endif
93 #ifdef B2500000
94 {B2500000, 2500000/200 + 0x8000u},
95 #endif
96 #ifdef B3000000
97 {B3000000, 3000000/200 + 0x8000u},
98 #endif
99 #ifdef B3500000
100 {B3500000, 3500000/200 + 0x8000u},
101 #endif
102 #ifdef B4000000
103 {B4000000, 4000000/200 + 0x8000u},
104 #endif
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) */
107 };
108
109 /*
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:
112 *
113 * #include <asm/termios.h>
114 * #include <asm/ioctls.h>
115 * struct termios2 t;
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);
121 */
122
123 enum { NUM_SPEEDS = ARRAY_SIZE(speeds) };
124
tty_baud_to_value(speed_t speed)125 unsigned FAST_FUNC tty_baud_to_value(speed_t speed)
126 {
127 int i = 0;
128
129 do {
130 if (speed == speeds[i].speed) {
131 if (speeds[i].value & 0x8000u) {
132 return ((unsigned)(speeds[i].value) & 0x7fffU) * 200;
133 }
134 return speeds[i].value;
135 }
136 } while (++i < NUM_SPEEDS);
137
138 return 0;
139 }
140
tty_value_to_baud(unsigned int value)141 speed_t FAST_FUNC tty_value_to_baud(unsigned int value)
142 {
143 int i = 0;
144
145 do {
146 if (value == tty_baud_to_value(speeds[i].speed)) {
147 return speeds[i].speed;
148 }
149 } while (++i < NUM_SPEEDS);
150
151 return (speed_t) - 1;
152 }
153
154 #if 0
155 /* testing code */
156 #include <stdio.h>
157
158 int main(void)
159 {
160 unsigned long v;
161 speed_t s;
162
163 for (v = 0 ; v < 1000000; v++) {
164 s = tty_value_to_baud(v);
165 if (s == (speed_t) -1) {
166 continue;
167 }
168 printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
169 }
170
171 printf("-------------------------------\n");
172
173 for (s = 0 ; s < 010017+1; s++) {
174 v = tty_baud_to_value(s);
175 if (!v) {
176 continue;
177 }
178 printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
179 }
180
181 return 0;
182 }
183 #endif
184