From bbac3265b2fde5613863ab1a60d20faf433dd9e9 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Tue, 1 Oct 2013 12:49:58 +1000
Subject: [PATCH] HAL_Linux: default to hal.console on stdout

---
 libraries/AP_HAL_Linux/HAL_Linux_Class.cpp |  6 +--
 libraries/AP_HAL_Linux/UARTDriver.cpp      | 45 ++++++++++++++--------
 libraries/AP_HAL_Linux/UARTDriver.h        |  6 ++-
 3 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp b/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp
index f5f7d00300..1cad64a97e 100644
--- a/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp
+++ b/libraries/AP_HAL_Linux/HAL_Linux_Class.cpp
@@ -12,9 +12,9 @@
 using namespace Linux;
 
 // 3 serial ports on Linux for now
-static LinuxUARTDriver uartADriver;
-static LinuxUARTDriver uartBDriver;
-static LinuxUARTDriver uartCDriver;
+static LinuxUARTDriver uartADriver(true);
+static LinuxUARTDriver uartBDriver(false);
+static LinuxUARTDriver uartCDriver(false);
 
 static LinuxSemaphore  i2cSemaphore;
 static LinuxI2CDriver  i2cDriver(&i2cSemaphore, "/dev/i2c-1");
diff --git a/libraries/AP_HAL_Linux/UARTDriver.cpp b/libraries/AP_HAL_Linux/UARTDriver.cpp
index 02c4a716e3..1582fce09c 100644
--- a/libraries/AP_HAL_Linux/UARTDriver.cpp
+++ b/libraries/AP_HAL_Linux/UARTDriver.cpp
@@ -20,10 +20,16 @@ extern const AP_HAL::HAL& hal;
 
 using namespace Linux;
 
-LinuxUARTDriver::LinuxUARTDriver() :
+LinuxUARTDriver::LinuxUARTDriver(bool default_console) :
     device_path(NULL),
-    _fd(-1)
+    _rd_fd(-1),
+    _wr_fd(-1)
 {
+    if (default_console) {
+        _rd_fd = 0;
+        _wr_fd = 1;
+        _console = true;
+    }
 }
 
 /*
@@ -44,14 +50,19 @@ void LinuxUARTDriver::begin(uint32_t b)
 
 void LinuxUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS) 
 {
-    if (!_initialised) {
+    if (device_path == NULL && _console) {
+        _rd_fd = 0;
+        _wr_fd = 1;
+        rxS = 512;
+        txS = 512;
+    } else if (!_initialised) {
         if (device_path == NULL) {
             return;
         }
         uint8_t retries = 0;
         while (retries < 5) {
-            _fd = open(device_path, O_RDWR);
-            if (_fd != -1) {
+            _rd_fd = open(device_path, O_RDWR);
+            if (_rd_fd != -1) {
                 break;
             }
             // sleep a bit and retry. There seems to be a NuttX bug
@@ -60,7 +71,8 @@ void LinuxUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
             hal.scheduler->delay(100);
             retries++;
         }
-        if (_fd == -1) {
+        _wr_fd = _rd_fd;
+        if (_rd_fd == -1) {
             fprintf(stdout, "Failed to open UART device %s - %s\n",
                     device_path, strerror(errno));
             return;
@@ -73,7 +85,7 @@ void LinuxUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
 
         // always run the file descriptor non-blocking, and deal with
         // blocking IO in the higher level calls
-        fcntl(_fd, F_SETFL, fcntl(_fd, F_GETFL, 0) | O_NONBLOCK);
+        fcntl(_rd_fd, F_SETFL, fcntl(_rd_fd, F_GETFL, 0) | O_NONBLOCK);
         
         if (rxS == 0) {
             rxS = 128;
@@ -90,14 +102,14 @@ void LinuxUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
     _initialised = false;
     while (_in_timer) hal.scheduler->delay(1);
 
-    if (b != 0) {
+    if (b != 0 && _rd_fd == _wr_fd) {
         // set the baud rate
         struct termios t;
-        tcgetattr(_fd, &t);
+        tcgetattr(_rd_fd, &t);
         cfsetspeed(&t, b);
         // disable LF -> CR/LF
         t.c_oflag &= ~ONLCR;
-        tcsetattr(_fd, TCSANOW, &t);
+        tcsetattr(_rd_fd, TCSANOW, &t);
     }
 
     /*
@@ -138,10 +150,11 @@ void LinuxUARTDriver::end()
 {
     _initialised = false;
     while (_in_timer) hal.scheduler->delay(1);
-    if (_fd != -1) {
-        close(_fd);
-        _fd = -1;
+    if (_rd_fd == _wr_fd && _rd_fd != -1) {
+        close(_rd_fd);
     }
+    _rd_fd = -1;
+    _wr_fd = -1;
     if (_readbuf) {
         free(_readbuf);
         _readbuf = NULL;
@@ -325,12 +338,12 @@ int LinuxUARTDriver::_write_fd(const uint8_t *buf, uint16_t n)
     int ret = 0;
 
     struct pollfd fds;
-    fds.fd = _fd;
+    fds.fd = _wr_fd;
     fds.events = POLLOUT;
     fds.revents = 0;
 
     if (poll(&fds, 1, 0) == 1) {
-        ret = ::write(_fd, buf, n);
+        ret = ::write(_wr_fd, buf, n);
     }
 
     if (ret > 0) {
@@ -347,7 +360,7 @@ int LinuxUARTDriver::_write_fd(const uint8_t *buf, uint16_t n)
 int LinuxUARTDriver::_read_fd(uint8_t *buf, uint16_t n)
 {
     int ret;
-    ret = ::read(_fd, buf, n);
+    ret = ::read(_rd_fd, buf, n);
     if (ret > 0) {
         BUF_ADVANCETAIL(_readbuf, ret);
     }
diff --git a/libraries/AP_HAL_Linux/UARTDriver.h b/libraries/AP_HAL_Linux/UARTDriver.h
index 495190e97c..00326d64e6 100644
--- a/libraries/AP_HAL_Linux/UARTDriver.h
+++ b/libraries/AP_HAL_Linux/UARTDriver.h
@@ -6,7 +6,7 @@
 
 class Linux::LinuxUARTDriver : public AP_HAL::UARTDriver {
 public:
-    LinuxUARTDriver();
+    LinuxUARTDriver(bool default_console);
     /* Linux implementations of UARTDriver virtual methods */
     void begin(uint32_t b);
     void begin(uint32_t b, uint16_t rxS, uint16_t txS);
@@ -31,8 +31,10 @@ public:
 
 private:
     const char *device_path;
-    int _fd;
+    int _rd_fd;
+    int _wr_fd;
     bool _nonblocking_writes;
+    bool _console;
     volatile bool _initialised;
     volatile bool _in_timer;