From 88f3052d99f3a599adeff4430f752fde4320ff64 Mon Sep 17 00:00:00 2001
From: Jon Trulson <jtrulson@ics.com>
Date: Thu, 30 Apr 2015 14:12:45 -0600
Subject: [PATCH] uart: use an unsigned int for baud rate rather than speed_t

uart.c contains a static conversion function that will translate known
baud rates into their speed_t counter parts.  If an unsupported baud
rate is selected, a diagnostic will be emitted via syslog and a
default of B9600 will be chosen.

Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
---
 api/mraa/uart.h   |  2 +-
 api/mraa/uart.hpp |  2 +-
 src/uart/uart.c   | 50 ++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/api/mraa/uart.h b/api/mraa/uart.h
index 468778a..298329c 100644
--- a/api/mraa/uart.h
+++ b/api/mraa/uart.h
@@ -83,7 +83,7 @@ char* mraa_uart_get_dev_path(mraa_uart_context dev);
  * @param baud desired baud rate
  * @return mraa_result_t
  */
-mraa_result_t mraa_uart_open_dev(mraa_uart_context dev, speed_t baud);
+mraa_result_t mraa_uart_open_dev(mraa_uart_context dev, unsigned int baud);
 
 /**
  * Close a device previously opened with mraa_uart_open_dev().
diff --git a/api/mraa/uart.hpp b/api/mraa/uart.hpp
index 82296b8..5642190 100644
--- a/api/mraa/uart.hpp
+++ b/api/mraa/uart.hpp
@@ -85,7 +85,7 @@ class Uart
      * @return mraa_result_t
      */
     mraa_result_t
-    openDevice(speed_t baud)
+    openDevice(unsigned int baud)
     {
         return mraa_uart_open_dev(m_uart, baud);
     }
diff --git a/src/uart/uart.c b/src/uart/uart.c
index b8d8ec5..bc04ef8 100644
--- a/src/uart/uart.c
+++ b/src/uart/uart.c
@@ -31,6 +31,49 @@
 #include "uart.h"
 #include "mraa_internal.h"
 
+// This function takes an unsigned int and converts it to a B* speed_t
+// that can be used with linux termios.
+static speed_t uint2speed(unsigned int speed)
+{
+    switch (speed) {
+    case 0:         return B0; // hangup, not too useful otherwise
+    case 50:        return B50;
+    case 75:        return B75;
+    case 110:       return B110;
+    case 150:       return B150;
+    case 200:       return B200;
+    case 300:       return B300;
+    case 600:       return B600;
+    case 1200:      return B1200;
+    case 1800:      return B1800;
+    case 2400:      return B2400;
+    case 4800:      return B4800;
+    case 9600:      return B9600;
+    case 19200:     return B19200;
+    case 38400:     return B38400;
+    case 57600:     return B57600;
+    case 115200:    return B115200;
+    case 230400:    return B230400;
+    case 460800:    return B460800;
+    case 500000:    return B500000;
+    case 576000:    return B576000;
+    case 921600:    return B921600;
+    case 1000000:   return B1000000;
+    case 1152000:   return B1152000;
+    case 1500000:   return B1500000;
+    case 2000000:   return B2000000;
+    case 2500000:   return B2500000;
+    case 3000000:   return B3000000;
+    case 3500000:   return B3500000;
+    case 4000000:   return B4000000;
+    }
+
+    // if we are here, then an unsupported baudrate was selected.
+    // Report it via syslog and return B9600, a common default.
+    syslog(LOG_ERR, "uart: unsupported baud rate, defaulting to 9600.");
+    return B9600;
+}
+
 mraa_uart_context
 mraa_uart_init(int index)
 {
@@ -112,7 +155,7 @@ mraa_uart_get_dev_path(mraa_uart_context dev)
 }
 
 mraa_result_t
-mraa_uart_open_dev(mraa_uart_context dev, speed_t baud)
+mraa_uart_open_dev(mraa_uart_context dev, unsigned int baud)
 {
     if (!dev) {
         syslog(LOG_ERR, "uart: open: context is NULL");
@@ -144,8 +187,9 @@ mraa_uart_open_dev(mraa_uart_context dev, speed_t baud)
     cfmakeraw(&termio);
 
     // set our baud rates
-    cfsetispeed(&termio, baud);
-    cfsetospeed(&termio, baud);
+    speed_t speed = uint2speed(baud);
+    cfsetispeed(&termio, speed);
+    cfsetospeed(&termio, speed);
 
     // make it so
     if (tcsetattr(dev->fd, TCSAFLUSH, &termio) < 0) {