Add RS485 mode

picocom.c

@@ -218,6 +218,7 @@ struct {
     int lower_dtr;
     int raise_rts;
     int raise_dtr;
+    int rs485;
     int quiet;
 } opts = {
     .port = NULL,
@@ -248,6 +249,7 @@ struct {
     .lower_dtr = 0,
     .raise_rts = 0,
     .raise_dtr = 0,
+    .rs485 = 0,
     .quiet = 0
 };
 
@@ -1657,6 +1659,7 @@ show_usage(char *name)
     printf("  --raise-rts\n");
     printf("  --lower-dtr\n");
     printf("  --raise-dtr\n");
+    printf("  --rs485\n");
     printf("  --<q>uiet\n");
     printf("  --<h>elp\n");
     printf("<map> is a comma-separated list of one or more of:\n");
@@ -1716,6 +1719,7 @@ parse_args(int argc, char *argv[])
         {"lower-dtr", no_argument, 0, 2},
         {"raise-rts", no_argument, 0, 3},
         {"raise-dtr", no_argument, 0, 4},
+        {"rs485", no_argument, 0, '4'},
         {"quiet", no_argument, 0, 'q'},
         {"help", no_argument, 0, 'h'},
         {0, 0, 0, 0}
@@ -1909,6 +1913,9 @@ parse_args(int argc, char *argv[])
         case 'q':
             opts.quiet = 1;
             break;
+        case '4':
+            opts.rs485 = 1;
+            break;
         case 'h':
             show_usage(argv[0]);
             exit(EXIT_SUCCESS);
@@ -1954,6 +1961,7 @@ parse_args(int argc, char *argv[])
     printf("picocom v%s\n", VERSION_STR);
     printf("\n");
     printf("port is        : %s\n", opts.port);
+    printf("rs485 mode     : %s\n", opts.rs485 ? "enabled" : "disabled");
     printf("flowcontrol    : %s\n", flow_str[opts.flow]);
     printf("baudrate is    : %d\n", opts.baud);
     printf("parity is      : %s\n", parity_str[opts.parity]);
@@ -2098,6 +2106,15 @@ main (int argc, char *argv[])
     /* Set DTR and RTS status, as quickly as possible after opening
        the serial port (i.e. before configuring it) */
     set_dtr_rts();
+
+    if ( opts.rs485 )
+        r = term_set_rs485(tty_fd, 1);
+    else
+        r = term_set_rs485(tty_fd, 0);
+
+    if ( r < 0 )
+        pinfo("!! failed to set rs485 mode !!");
+
     r = term_apply(tty_fd, 0);
     if ( r < 0 )
         fatal("failed to config port: %s",

term.c

@@ -43,10 +43,14 @@
  * CMSPAR, so we use the value from the generic bits/termios.h
  */
 #ifdef __linux__
+#define USE_RS485
 #ifndef CMSPAR
 #define CMSPAR 010000000000
 #endif
 #endif
+#ifdef USE_RS485
+#include <linux/serial.h>
+#endif
 
 /* Some BSDs (and possibly other systems too) have no mark / space
  * parity support, and they don't define CMSPAR. Use a zero CMSPAR in
@@ -759,6 +763,56 @@ term_apply (int fd, int now)
 
 /***************************************************************************/
 
+int
+term_set_rs485 (int fd, int status)
+{
+    int rval, i;
+
+    rval = 0;
+
+    do { /* dummy */
+
+        i = term_find(fd);
+        if ( i < 0 ) {
+            rval = -1;
+            break;
+        }
+
+#ifdef USE_RS485
+#ifdef USE_IOCTL
+        {
+            int r;
+
+            struct serial_rs485 rs485conf;
+            memset(&rs485conf, 0x0, sizeof(struct serial_rs485));
+
+            if ( status == 1 ) {
+                rs485conf.flags |= SER_RS485_ENABLED;
+                rs485conf.flags |= SER_RS485_RTS_ON_SEND;
+                rs485conf.flags &= ~(SER_RS485_RTS_AFTER_SEND);
+            }
+
+            r = ioctl(fd, TIOCSRS485, &rs485conf);
+            if ( r < 0 ) {
+                rval = -1;
+                break;
+            }
+        }
+#else
+        rval = -1;
+#endif /* of USE_IOCTL */
+#else
+        /* If 485 not available return error only if trying to set 485 mode */
+        if ( status == 1 )
+            rval = -1
+#endif
+    } while (0);
+
+    return rval;
+}
+
+/***************************************************************************/
+
 int
 term_set_raw (int fd)
 {

term.h

@@ -44,6 +44,7 @@
  * F term_apply - configure a device to the settings in "nexttermios"
  * F term_revert - discard "nexttermios" by copying-over "currtermios"
  * F term_refresh - update "currtermios" from the device
+ * F term_set_rs485 - set the rs485 mode of a device
  * F term_set_raw - set "nexttermios" to raw mode
  * F term_set_baudrate - set the baudrate in "nexttermios"
  * F term_set_parity - set the parity mode in "nexttermios"
@@ -383,6 +384,14 @@ int term_reset (int fd);
  */
 int term_refresh (int fd);
 
+/* F term_set_rs485
+ *
+ * Sets the managed filedes "fd" to rs485 mode.
+ *
+ * Returns negative on failure, non-negative on success.
+ */
+int term_set_rs485 (int fd, int status);
+
 /* F term_set_raw
  *
  * Sets the "nexttermios" structure associated with the managed