1
2
3
4
5
6#include <linux/types.h>
7#include <linux/kernel.h>
8#include <linux/termios.h>
9#include <linux/tty.h>
10#include <linux/export.h>
11
12
13
14
15
16
17
18
19static const speed_t baud_table[] = {
20 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
21 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800,
22#ifdef __sparc__
23 76800, 153600, 307200, 614400, 921600, 500000, 576000,
24 1000000, 1152000, 1500000, 2000000
25#else
26 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
27 2500000, 3000000, 3500000, 4000000
28#endif
29};
30
31static const tcflag_t baud_bits[] = {
32 B0, B50, B75, B110, B134, B150, B200, B300, B600, B1200, B1800, B2400,
33 B4800, B9600, B19200, B38400, B57600, B115200, B230400, B460800,
34#ifdef __sparc__
35 B76800, B153600, B307200, B614400, B921600, B500000, B576000,
36 B1000000, B1152000, B1500000, B2000000
37#else
38 B500000, B576000, B921600, B1000000, B1152000, B1500000, B2000000,
39 B2500000, B3000000, B3500000, B4000000
40#endif
41};
42
43static int n_baud_table = ARRAY_SIZE(baud_table);
44
45
46
47
48
49
50
51
52
53
54
55
56
57speed_t tty_termios_baud_rate(struct ktermios *termios)
58{
59 unsigned int cbaud;
60
61 cbaud = termios->c_cflag & CBAUD;
62
63#ifdef BOTHER
64
65 if (cbaud == BOTHER)
66 return termios->c_ospeed;
67#endif
68 if (cbaud & CBAUDEX) {
69 cbaud &= ~CBAUDEX;
70
71 if (cbaud < 1 || cbaud + 15 > n_baud_table)
72 termios->c_cflag &= ~CBAUDEX;
73 else
74 cbaud += 15;
75 }
76 return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
77}
78EXPORT_SYMBOL(tty_termios_baud_rate);
79
80
81
82
83
84
85
86
87
88
89
90
91
92speed_t tty_termios_input_baud_rate(struct ktermios *termios)
93{
94#ifdef IBSHIFT
95 unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
96
97 if (cbaud == B0)
98 return tty_termios_baud_rate(termios);
99#ifdef BOTHER
100
101 if (cbaud == BOTHER)
102 return termios->c_ispeed;
103#endif
104 if (cbaud & CBAUDEX) {
105 cbaud &= ~CBAUDEX;
106
107 if (cbaud < 1 || cbaud + 15 > n_baud_table)
108 termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
109 else
110 cbaud += 15;
111 }
112 return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
113#else
114 return tty_termios_baud_rate(termios);
115#endif
116}
117EXPORT_SYMBOL(tty_termios_input_baud_rate);
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141void tty_termios_encode_baud_rate(struct ktermios *termios,
142 speed_t ibaud, speed_t obaud)
143{
144 int i = 0;
145 int ifound = -1, ofound = -1;
146 int iclose = ibaud/50, oclose = obaud/50;
147 int ibinput = 0;
148
149 if (obaud == 0)
150 ibaud = 0;
151
152 termios->c_ispeed = ibaud;
153 termios->c_ospeed = obaud;
154
155#ifdef IBSHIFT
156 if ((termios->c_cflag >> IBSHIFT) & CBAUD)
157 ibinput = 1;
158#endif
159#ifdef BOTHER
160
161
162
163
164 if ((termios->c_cflag & CBAUD) == BOTHER) {
165 oclose = 0;
166 if (!ibinput)
167 iclose = 0;
168 }
169 if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
170 iclose = 0;
171#endif
172 termios->c_cflag &= ~CBAUD;
173#ifdef IBSHIFT
174 termios->c_cflag &= ~(CBAUD << IBSHIFT);
175#endif
176
177
178
179
180
181
182
183
184 do {
185 if (obaud - oclose <= baud_table[i] &&
186 obaud + oclose >= baud_table[i]) {
187 termios->c_cflag |= baud_bits[i];
188 ofound = i;
189 }
190 if (ibaud - iclose <= baud_table[i] &&
191 ibaud + iclose >= baud_table[i]) {
192
193
194 if (ofound == i && !ibinput)
195 ifound = i;
196#ifdef IBSHIFT
197 else {
198 ifound = i;
199 termios->c_cflag |= (baud_bits[i] << IBSHIFT);
200 }
201#endif
202 }
203 } while (++i < n_baud_table);
204
205
206
207
208
209#ifdef BOTHER
210 if (ofound == -1)
211 termios->c_cflag |= BOTHER;
212
213
214 if (ifound == -1 && (ibaud != obaud || ibinput))
215 termios->c_cflag |= (BOTHER << IBSHIFT);
216#else
217 if (ifound == -1 || ofound == -1)
218 pr_warn_once("tty: Unable to return correct speed data as your architecture needs updating.\n");
219#endif
220}
221EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
222
223
224
225
226
227
228
229
230
231
232
233void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
234{
235 tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
236}
237EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
238