LXR busybox/libbb/speed

   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 tarball for details.
   8 */
   9
  10#include <termios.h>
  11#include "libbb.h"
  12
  13struct speed_map {
  14        unsigned short speed;
  15        unsigned short value;
  16};
  17
  18static const struct speed_map speeds[] = {
  19        {B0, 0},
  20        {B50, 50},
  21        {B75, 75},
  22        {B110, 110},
  23        {B134, 134},
  24        {B150, 150},
  25        {B200, 200},
  26        {B300, 300},
  27        {B600, 600},
  28        {B1200, 1200},
  29        {B1800, 1800},
  30        {B2400, 2400},
  31        {B4800, 4800},
  32        {B9600, 9600},
  33#ifdef  B19200
  34        {B19200, 19200},
  35#elif defined(EXTA)
  36        {EXTA, 19200},
  37#endif
  38#ifdef  B38400
  39        {B38400, 38400/256 + 0x8000U},
  40#elif defined(EXTB)
  41        {EXTB, 38400/256 + 0x8000U},
  42#endif
  43#ifdef B57600
  44        {B57600, 57600/256 + 0x8000U},
  45#endif
  46#ifdef B115200
  47        {B115200, 115200/256 + 0x8000U},
  48#endif
  49#ifdef B230400
  50        {B230400, 230400/256 + 0x8000U},
  51#endif
  52#ifdef B460800
  53        {B460800, 460800/256 + 0x8000U},
  54#endif
  55};
  56
  57enum { NUM_SPEEDS = ARRAY_SIZE(speeds) };
  58
  59unsigned FAST_FUNC tty_baud_to_value(speed_t speed)
  60{
  61        int i = 0;
  62
  63        do {
  64                if (speed == speeds[i].speed) {
  65                        if (speeds[i].value & 0x8000U) {
  66                                return ((unsigned long) (speeds[i].value) & 0x7fffU) * 256;
  67                        }
  68                        return speeds[i].value;
  69                }
  70        } while (++i < NUM_SPEEDS);
  71
  72        return 0;
  73}
  74
  75speed_t FAST_FUNC tty_value_to_baud(unsigned int value)
  76{
  77        int i = 0;
  78
  79        do {
  80                if (value == tty_baud_to_value(speeds[i].speed)) {
  81                        return speeds[i].speed;
  82                }
  83        } while (++i < NUM_SPEEDS);
  84
  85        return (speed_t) - 1;
  86}
  87
  88#if 0
  89/* testing code */
  90#include <stdio.h>
  91
  92int main(void)
  93{
  94        unsigned long v;
  95        speed_t s;
  96
  97        for (v = 0 ; v < 500000; v++) {
  98                s = tty_value_to_baud(v);
  99                if (s == (speed_t) -1) {
 100                        continue;
 101                }
 102                printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
 103        }
 104
 105        printf("-------------------------------\n");
 106
 107        for (s = 0 ; s < 010017+1; s++) {
 108                v = tty_baud_to_value(s);
 109                if (!v) {
 110                        continue;
 111                }
 112                printf("v = %lu -- s = %0lo\n", v, (unsigned long) s);
 113        }
 114
 115        return 0;
 116}
 117#endif
 118