slcand: add flow control option

Add option '-t' to specify flow control type. Two types are
supported: 'hw' - RTS/CTS and 'sw' - XON/XOFF.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/slcand.c b/slcand.c
index 30f5127f8cd8b293643acea9af584c1ed58fcf9c..24af9717482d2412f6c3885a772867375e011643 100644 (file)
--- a/slcand.c
+++ b/slcand.c
@@ -69,6 +69,11 @@
 #define EXIT_SUCCESS 0
 #define EXIT_FAILURE 1
 
+/* UART flow control types */
+#define FLOW_NONE 0
+#define FLOW_HW 1
+#define FLOW_SW 2
+
 void print_usage(char *prg)
 {
        fprintf(stderr, "\nUsage: %s [options] <tty> [canif-name]\n\n", prg);
@@ -77,6 +82,7 @@ void print_usage(char *prg)
        fprintf(stderr, "         -f         (read status flags with 'F\\r' to reset error states)\n");
        fprintf(stderr, "         -s <speed> (set CAN speed 0..8)\n");
        fprintf(stderr, "         -S <speed> (set UART speed in baud)\n");
+       fprintf(stderr, "         -t <type>  (set UART flow control type 'hw' or 'sw')\n");
        fprintf(stderr, "         -b <btr>   (set bit time register value)\n");
        fprintf(stderr, "         -F         (stay in foreground; no daemonize)\n");
        fprintf(stderr, "         -h         (show this help page)\n");
@@ -300,6 +306,7 @@ int main(int argc, char *argv[])
        char *speed = NULL;
        char *uart_speed_str = NULL;
        long int uart_speed = 0;
+       int flow_type = FLOW_NONE;
        char *btr = NULL;
        int run_as_daemon = 1;
        pid_t parent_pid = 0;
@@ -309,7 +316,7 @@ int main(int argc, char *argv[])
 
        ttypath[0] = '\0';
 
-       while ((opt = getopt(argc, argv, "ocfs:S:b:?hF")) != -1) {
+       while ((opt = getopt(argc, argv, "ocfs:S:t:b:?hF")) != -1) {
                switch (opt) {
                case 'o':
                        send_open = 1;
@@ -336,6 +343,16 @@ int main(int argc, char *argv[])
                                exit(EXIT_FAILURE);
                        }
                        break;
+               case 't':
+                       if (!strcmp(optarg, "hw")) {
+                               flow_type = FLOW_HW;
+                       } else if (!strcmp(optarg, "sw")) {
+                               flow_type = FLOW_SW;
+                       } else {
+                               fprintf(stderr, "Unsupported flow type (%s)\n", optarg);
+                               exit(EXIT_FAILURE);
+                       }
+                       break;
                case 'b':
                        btr = optarg;
                        if (strlen(btr) > 6)
@@ -401,10 +418,21 @@ int main(int argc, char *argv[])
        old_ispeed = cfgetispeed(&tios);
        old_ospeed = cfgetospeed(&tios);
 
+       /* Reset UART settings */
+       cfmakeraw(&tios);
+       tios.c_iflag &= ~IXOFF;
+       tios.c_cflag &= ~CRTSCTS;
+
        /* Baud Rate */
        cfsetispeed(&tios, look_up_uart_speed(uart_speed));
        cfsetospeed(&tios, look_up_uart_speed(uart_speed));
 
+       /* Flow control */
+       if (flow_type == FLOW_HW)
+               tios.c_cflag |= CRTSCTS;
+       else if (flow_type == FLOW_SW)
+               tios.c_iflag |= (IXON | IXOFF);
+
        /* apply changes */
        if (tcsetattr(fd, TCSADRAIN, &tios) < 0)
                syslog(LOG_NOTICE, "Cannot set attributes for device \"%s\": %s!\n", ttypath, strerror(errno));