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 #include "libbb.h"
10
11 struct speed_map {
12 #if defined __FreeBSD__ \
13 || (defined B115200 && B115200 > 0xffff) \
14 || (defined B230400 && B230400 > 0xffff) \
15 || (defined B460800 && B460800 > 0xffff) \
16 || (defined B921600 && B921600 > 0xffff) \
17 || (defined B1152000 && B1152000 > 0xffff) \
18 || (defined B1000000 && B1000000 > 0xffff) \
19 || (defined B2000000 && B2000000 > 0xffff) \
20 || (defined B3000000 && B3000000 > 0xffff) \
21 || (defined B4000000 && B4000000 > 0xffff)
22 /* On FreeBSD, B<num> constants don't fit into a short */
23 unsigned speed;
24 #else
25 unsigned short speed;
26 #endif
27 unsigned short value;
28 };
29
30 /* On Linux, Bxx constants are 0..15 (up to B38400) and 0x1001..0x100f */
31 static const struct speed_map speeds[] ALIGN4 = {
32 {B0, 0},
33 {B50, 50},
34 {B75, 75},
35 {B110, 110},
36 {B134, 134},
37 {B150, 150},
38 {B200, 200},
39 {B300, 300},
40 {B600, 600},
41 {B1200, 1200},
42 {B1800, 1800},
43 {B2400, 2400},
44 {B4800, 4800},
45 {B9600, 9600},
46 #ifdef B19200
47 {B19200, 19200},
48 #elif defined(EXTA)
49 {EXTA, 19200},
50 #endif
51 /* 19200 = 0x4b00 */
52 /* 38400 = 0x9600, this value would use bit#15 if not "/200" encoded: */
53 #ifdef B38400
54 {B38400, 38400/200 + 0x8000u},
55 #elif defined(EXTB)
56 {EXTB, 38400/200 + 0x8000u},
57 #endif
58 #ifdef B57600
59 {B57600, 57600/200 + 0x8000u},
60 #endif
61 #ifdef B115200
62 {B115200, 115200/200 + 0x8000u},
63 #endif
64 #ifdef B230400
65 {B230400, 230400/200 + 0x8000u},
66 #endif
67 #ifdef B460800
68 {B460800, 460800/200 + 0x8000u},
69 #endif
70 #ifdef B576000
71 {B576000, 576000/200 + 0x8000u},
72 #endif
73 #ifdef B921600
74 {B921600, 921600/200 + 0x8000u},
75 #endif
76 #ifdef B1152000
77 {B1152000, 1152000/200 + 0x8000u},
78 #endif
79
80 #ifdef B500000
81 {B500000, 500000/200 + 0x8000u},
82 #endif
83 #ifdef B1000000
84 {B1000000, 1000000/200 + 0x8000u},
85 #endif
86 #ifdef B1500000
87 {B1500000, 1500000/200 + 0x8000u},
88 #endif
89 #ifdef B2000000
90 {B2000000, 2000000/200 + 0x8000u},
91 #endif
92 #ifdef B2500000
93 {B2500000, 2500000/200 + 0x8000u},
94 #endif
95 #ifdef B3000000
96 {B3000000, 3000000/200 + 0x8000u},
97 #endif
98 #ifdef B3500000
99 {B3500000, 3500000/200 + 0x8000u},
100 #endif
101 #ifdef B4000000
102 {B4000000, 4000000/200 + 0x8000u},
103 #endif
104 /* 4000000/200 = 0x4e20, bit#15 still does not interfere with the value */
105 /* (can use /800 if higher speeds would appear, /1600 won't work for B500000) */
106 };
107
108 /*
109 * TODO: maybe we can just bite the bullet, ditch the table and use termios2
110 * Linux API (supports arbitrary baud rates, no Bxxxx mess needed)? Example:
111 *
112 * #include <asm/termios.h>
113 * #include <asm/ioctls.h>
114 * struct termios2 t;
115 * ioctl(fd, TCGETS2, &t);
116 * t.c_ospeed = t.c_ispeed = 543210;
117 * t.c_cflag &= ~CBAUD;
118 * t.c_cflag |= BOTHER;
119 * ioctl(fd, TCSETS2, &t);
120 */
121
122 enum { NUM_SPEEDS = ARRAY_SIZE(speeds) };
123
tty_baud_to_value(speed_t speed)124 unsigned FAST_FUNC tty_baud_to_value(speed_t speed)
125 {
126 int i = 0;
127
128 do {
129 if (speed == speeds[i].speed) {
130 if (speeds[i].value & 0x8000u) {
131 return ((unsigned)(speeds[i].value) & 0x7fffU) * 200;
132 }
133 return speeds[i].value;
134 }
135 } while (++i < NUM_SPEEDS);
136
137 return 0;
138 }
139
tty_value_to_baud(unsigned int value)140 speed_t FAST_FUNC tty_value_to_baud(unsigned int value)
141 {
142 int i = 0;
143
144 do {
145 if (value == tty_baud_to_value(speeds[i].speed)) {
146 return speeds[i].speed;
147 }
148 } while (++i < NUM_SPEEDS);
149
150 return (speed_t) - 1;
151 }
152
153 #if 0
154 /* testing code */
155 #include <stdio.h>
156
157 int main(void)
158 {
159 unsigned long v;
160 speed_t s;
161
162 for (v = 0 ; v < 1000000; v++) {
163 s = tty_value_to_baud(v);
164 if (s == (speed_t) -1) {
165 continue;
166 }
167 printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
168 }
169
170 printf("-------------------------------\n");
171
172 for (s = 0 ; s < 010017+1; s++) {
173 v = tty_baud_to_value(s);
174 if (!v) {
175 continue;
176 }
177 printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
178 }
179
180 return 0;
181 }
182 #endif
183