From deec83a4eeddd5c3b2d4df041aede2bceb8867da Mon Sep 17 00:00:00 2001
From: Martin Lund <martin.lund@keep-it-simple.com>
Date: Sat, 28 May 2016 16:02:21 +0200
Subject: [PATCH] Added support for non-standard baud rates

Only enabled when possible, that is, when the BOTHER definition is
available.

It is untested but it should work as described here:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=683826

Some Cypress USB<->serial devices supposedly supports arbitrary speeds.
---
 configure.ac |  3 +++
 src/tty.c    | 28 +++++++++++++++++++++++++---
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index b8a0e17..e80cb75 100644
--- a/configure.ac
+++ b/configure.ac
@@ -87,6 +87,9 @@ TIO_CHECK_BAUDRATES(
 
 AC_DEFINE_UNQUOTED([AUTOCONF_BAUDRATE_CASES],[$BAUDRATE_CASES],[Switch cases for detected baud rates])
 
+# Check that it is possible to set arbitrary baud rates using BOTHER
+AC_CHECK_DECLS([BOTHER], [], [], [[#include <asm/termios.h>]])
+
 AC_CONFIG_FILES([Makefile])
 AC_CONFIG_FILES([src/Makefile])
 AC_CONFIG_FILES([src/bash-completion/tio])
diff --git a/src/tty.c b/src/tty.c
index f60d8da..fccd5ff 100644
--- a/src/tty.c
+++ b/src/tty.c
@@ -45,8 +45,13 @@ static struct termios tio, new_stdout, old_stdout, old_tio;
 static unsigned long rx_total = 0, tx_total = 0;
 static bool connected = false;
 static bool tainted = false;
+static bool standard_baudrate = true;
 static int fd;
 
+#ifndef BOTHER
+#define BOTHER 0010000
+#endif
+
 #define tio_printf(format, args...) \
 { \
     if (tainted) putchar('\n'); \
@@ -156,7 +161,7 @@ void stdout_restore(void)
 
 void tty_configure(void)
 {
-    speed_t baudrate;
+    speed_t baudrate = 0;
 
     memset(&tio, 0, sizeof(tio));
 
@@ -177,12 +182,25 @@ void tty_configure(void)
         AUTOCONF_BAUDRATE_CASES
 
         default:
+#if !HAVE_DECL_BOTHER
             error_printf("Invalid baud rate");
             exit(EXIT_FAILURE);
+#else
+            standard_baudrate = false;
+            break;
+#endif
     }
 
-    cfsetispeed(&tio, baudrate);
-    cfsetospeed(&tio, baudrate);
+    if (standard_baudrate)
+    {
+        cfsetispeed(&tio, baudrate);
+        cfsetospeed(&tio, baudrate);
+    } else
+    {
+        tio.c_ispeed = tio.c_ospeed = baudrate;
+        tio.c_cflag &= ~CBAUD;
+        tio.c_cflag |= BOTHER;
+    }
 
     /* Set databits */
     tio.c_cflag &= ~CSIZE;
@@ -374,6 +392,10 @@ int tty_connect(void)
     /* Flush stale I/O data (if any) */
     tcflush(fd, TCIOFLUSH);
 
+    /* Warn if non standard baud rate is used */
+    if (!standard_baudrate)
+        tio_printf("Warning: Using a non standard baud rate");
+
     /* Print connect status */
     tio_printf("Connected");
     connected = true;