git.zerfleddert.de Git - hmcfgusb/blob - culfw.c

   1 /* culfw driver
   2  *
   3  * Copyright (c) 2013 Michael Gernoth <michael@gernoth.net>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to
   7  * deal in the Software without restriction, including without limitation the
   8  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   9  * sell copies of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <inttypes.h>
  27 #include <poll.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30 #include <string.h>
  31 #include <strings.h>
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34 #include <termios.h>
  35 #include <unistd.h>
  36
  37 #include "culfw.h"
  38
  39 struct culfw_dev *culfw_init(char *device, uint32_t speed, culfw_cb_fn cb, void *data)
  40 {
  41         struct culfw_dev *dev = NULL;
  42         struct termios oldtio, tio;
  43         uint32_t brate;
  44
  45         switch(speed) {
  46                 case 115200:
  47                         brate = B115200;
  48                         break;
  49                 case 57600:
  50                         brate = B57600;
  51                         break;
  52                 case 38400:
  53                         brate = B38400;
  54                         break;
  55                 case 19200:
  56                         brate = B19200;
  57                         break;
  58                 case 9600:
  59                         brate = B9600;
  60                         break;
  61                 default:
  62                         fprintf(stderr, "Unsupported baud-rate: %u\n", speed);
  63                         return NULL;
  64                         break;
  65         }
  66
  67         dev = malloc(sizeof(struct culfw_dev));
  68         if (dev == NULL) {
  69                 perror("malloc(struct culfw_dev)");
  70                 return NULL;
  71         }
  72
  73         memset(dev, 0, sizeof(struct culfw_dev));
  74
  75         dev->fd = open(device, O_RDWR | O_NOCTTY);
  76         if (dev->fd < 0) {
  77                 perror("open(culfw)");
  78                 goto out;
  79         }
  80
  81         if (tcgetattr(dev->fd, &oldtio) == -1) {
  82                 perror("tcgetattr");
  83                 goto out2;
  84         }
  85
  86         memset(&tio, 0, sizeof(tio));
  87
  88         tio.c_cflag = brate | CS8 | CLOCAL | CREAD;
  89         tio.c_iflag = IGNPAR | ICRNL;
  90         tio.c_oflag = 0;
  91         tio.c_lflag = ICANON;
  92         tio.c_cc[VTIME] = 0;
  93         tio.c_cc[VMIN] = 1;
  94
  95         tcflush(dev->fd, TCIFLUSH);
  96         if (tcsetattr(dev->fd, TCSANOW, &tio) == -1) {
  97                 perror("tcsetattr");
  98                 goto out2;
  99         }
 100
 101         dev->cb = cb;
 102         dev->cb_data = data;
 103
 104         return dev;
 105
 106 out2:
 107         close(dev->fd);
 108 out:
 109         free(dev);
 110         return NULL;
 111 }
 112
 113 int culfw_send(struct culfw_dev *dev, char *cmd, int cmdlen)
 114 {
 115         int w = 0;
 116         int ret;
 117
 118         do {
 119                 ret = write(dev->fd, cmd + w, cmdlen - w);
 120                 if (ret < 0) {
 121                         perror("write");
 122                         return 0;
 123                 }
 124                 w += ret;
 125         } while (w < cmdlen);
 126
 127         return 1;
 128 }
 129
 130 int culfw_poll(struct culfw_dev *dev, int timeout)
 131 {
 132         struct pollfd pfds[1];
 133         int ret;
 134         int r = 0;
 135         uint8_t buf[1024];
 136
 137         errno = 0;
 138
 139         memset(pfds, 0, sizeof(struct pollfd) * 1);
 140
 141         pfds[0].fd = dev->fd;
 142         pfds[0].events = POLLIN;
 143
 144         ret = poll(pfds, 1, timeout * 1000);
 145         if (ret == -1)
 146                 return -1;
 147
 148         if (ret == 0) {
 149                 errno = ETIMEDOUT;
 150                 return -1;
 151         }
 152
 153         if (!(pfds[0].revents & POLLIN)) {
 154                 errno = EIO;
 155                 return -1;
 156         }
 157
 158         memset(buf, 0, sizeof(buf));
 159         r = read(dev->fd, buf, sizeof(buf));
 160         if (r < 0)
 161                 return -1;
 162
 163         if (r == 0) {
 164                 errno = EOF;
 165                 return -1;
 166         }
 167
 168         dev->cb(buf, r, dev->cb_data);
 169
 170         errno = 0;
 171         return -1;
 172 }
 173
 174 void culfw_close(struct culfw_dev *dev)
 175 {
 176         close(dev->fd);
 177 }