Merge branch 'origin/x300/bug469' into maint

Fixing empty GPS NMEA strings on X300

3 files changed, 121 insertions, 25 deletions

diff --git a/firmware/x300/x300/x300_main.c b/firmware/x300/x300/x300_main.c
index d7fd32ac3..d865e1d09 100644
--- a/firmware/x300/x300/x300_main.c
+++ b/firmware/x300/x300/x300_main.c
@@ -1,4 +1,4 @@
-// Copyright 2013 Ettus Research LLC
+// Copyright 2013-2014 Ettus Research LLC
 
 #include "x300_init.h"
 #include "x300_defs.h"
@@ -345,12 +345,12 @@ static void handle_uarts(void)
     static uint32_t rxoffset = 0;
     for (int rxch = wb_uart_getc(UART0_BASE); rxch != -1; rxch = wb_uart_getc(UART0_BASE))
     {
-        rxoffset = (rxoffset+1) % (NUM_POOL_WORDS32*4);
+        rxoffset++;
         const int shift = ((rxoffset%4) * 8);
         static uint32_t rxword32 = 0;
         if (shift == 0) rxword32 = 0;
-        rxword32 |= ((uint32_t) rxch) << ((rxoffset%4) * 8);
-        rxpool[rxoffset/4] = rxword32;
+        rxword32 |= ((uint32_t) rxch & 0xFF) << shift;
+        rxpool[(rxoffset/4) % NUM_POOL_WORDS32] = rxword32;
         shmem[X300_FW_SHMEM_UART_RX_INDEX] = rxoffset;
     }
 
diff --git a/host/lib/usrp/gps_ctrl.cpp b/host/lib/usrp/gps_ctrl.cpp
index d327a84f9..f4d5cd8e8 100644
--- a/host/lib/usrp/gps_ctrl.cpp
+++ b/host/lib/usrp/gps_ctrl.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright 2010-2011 Ettus Research LLC
+// Copyright 2010-2011,2014 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -17,6 +17,7 @@
 
 #include <uhd/usrp/gps_ctrl.hpp>
 #include <uhd/utils/msg.hpp>
+#include <uhd/utils/log.hpp>
 #include <uhd/exception.hpp>
 #include <uhd/types/sensors.hpp>
 #include <boost/algorithm/string.hpp>
@@ -62,6 +63,27 @@ private:
     return std::string();
   }
 
+    static bool is_nmea_checksum_ok(std::string nmea)
+    {
+        if (nmea.length() < 5 || nmea[0] != '$' || nmea[nmea.length()-3] != '*')
+            return false;
+
+        std::stringstream ss;
+        boost::uint32_t string_crc;
+        boost::uint32_t calculated_crc = 0;
+
+        // get crc from string
+        ss << std::hex << nmea.substr(nmea.length()-2, 2);
+        ss >> string_crc;
+
+        // calculate crc
+        for (size_t i = 1; i < nmea.length()-3; i++)
+            calculated_crc ^= nmea[i];
+
+        // return comparison
+        return (string_crc == calculated_crc);
+    }
+
   std::string update_cached_sensors(const std::string sensor) {
     if(not gps_detected() || (gps_type != GPS_TYPE_INTERNAL_GPSDO)) {
         UHD_MSG(error) << "get_stat(): unsupported GPS or no GPS detected";
@@ -70,24 +92,36 @@ private:
 
     const std::list<std::string> list = boost::assign::list_of("GPGGA")("GPRMC")("SERVO");
     static const boost::regex status_regex("\\d\\d-\\d\\d-\\d\\d");
+    static const boost::regex gp_msg_regex("^\\$GP.*,\\*[0-9A-F]{2}$");
     std::map<std::string,std::string> msgs;
 
     // Get all GPSDO messages available
     // Creating a map here because we only want the latest of each message type
     for (std::string msg = _recv(); msg.length(); msg = _recv())
     {
-        if (msg.length() < 6)
-            continue;
-
         // Strip any end of line characters
         erase_all(msg, "\r");
         erase_all(msg, "\n");
 
+        if (msg.length() < 6)
+        {
+            UHD_LOGV(regularly) << __FUNCTION__ << ": Short NMEA string: " << msg << std::endl;
+            continue;
+        }
+
         // Look for SERVO message
         if (boost::regex_search(msg, status_regex, boost::regex_constants::match_continuous))
+        {
             msgs["SERVO"] = msg;
-        else
+        }
+        else if (boost::regex_match(msg, gp_msg_regex) and is_nmea_checksum_ok(msg))
+        {
             msgs[msg.substr(1,5)] = msg;
+        }
+        else
+        {
+            UHD_LOGV(regularly) << __FUNCTION__ << ": Malformed NMEA string: " << msg << std::endl;
+        }
     }
 
     boost::system_time time = boost::get_system_time();
@@ -131,7 +165,6 @@ public:
       }
       else if(reply.substr(0, 3) == "$GP") i_heard_some_nmea = true; //but keep looking for that "Command Error" response
       else if(reply.length() != 0) i_heard_something_weird = true; //probably wrong baud rate
-      sleep(milliseconds(GPS_TIMEOUT_DELAY_MS));
     }
 
     if((i_heard_some_nmea) && (gps_type != GPS_TYPE_INTERNAL_GPSDO)) gps_type = GPS_TYPE_GENERIC_NMEA;
diff --git a/host/lib/usrp/x300/x300_fw_uart.cpp b/host/lib/usrp/x300/x300_fw_uart.cpp
index 943b2d9fa..b0fae124d 100644
--- a/host/lib/usrp/x300/x300_fw_uart.cpp
+++ b/host/lib/usrp/x300/x300_fw_uart.cpp
@@ -38,6 +38,8 @@ struct x300_uart_iface : uart_iface
         rxpool = _iface->peek32(SR_ADDR(X300_FW_SHMEM_BASE, X300_FW_SHMEM_UART_RX_ADDR));
         txpool = _iface->peek32(SR_ADDR(X300_FW_SHMEM_BASE, X300_FW_SHMEM_UART_TX_ADDR));
         poolsize = _iface->peek32(SR_ADDR(X300_FW_SHMEM_BASE, X300_FW_SHMEM_UART_WORDS32));
+        _rxcache.resize(poolsize);
+        _last_device_rxoffset = rxoffset;
         //this->write_uart("HELLO UART\n");
         //this->read_uart(0.1);
     }
@@ -54,6 +56,7 @@ struct x300_uart_iface : uart_iface
 
     void write_uart(const std::string &buff)
     {
+        boost::mutex::scoped_lock(_write_mutex);
         BOOST_FOREACH(const char ch, buff)
         {
             if (ch == '\n') this->putchar('\r');
@@ -63,39 +66,99 @@ struct x300_uart_iface : uart_iface
 
     int getchar(void)
     {
-        if (_iface->peek32(SR_ADDR(X300_FW_SHMEM_BASE, X300_FW_SHMEM_UART_RX_INDEX)) != rxoffset)
+        if (rxoffset == _last_device_rxoffset)
+            return -1;
+
+        rxoffset++;
+        return static_cast<int>(_rxcache[(rxoffset/4) % poolsize] >> ((rxoffset%4)*8) & 0xFF);
+    }
+
+    void update_cache(void)
+    {
+        boost::uint32_t device_rxoffset = _iface->peek32(SR_ADDR(X300_FW_SHMEM_BASE, X300_FW_SHMEM_UART_RX_INDEX));
+        boost::uint32_t delta = device_rxoffset - rxoffset;
+
+        while (delta)
         {
-            const int shift = ((rxoffset%4) * 8);
-            const char ch = _iface->peek32(SR_ADDR(rxpool, rxoffset/4)) >> shift;
-            rxoffset = (rxoffset + 1) % (poolsize*4);
-            return ch;
+            if (delta >= poolsize*4)
+            {
+                // all the data is new - reload the entire cache
+                for (boost::uint32_t i = 0; i < poolsize; i++)
+                    _rxcache[i] = _iface->peek32(SR_ADDR(rxpool, i));
+
+                // set rxoffset to the end of the first string
+                rxoffset = device_rxoffset - (poolsize*4) + 1;
+                while (static_cast<char>((_rxcache[(rxoffset/4) % poolsize] >> ((rxoffset%4)*8) & 0xFF)) != '\n')
+                    ++rxoffset;
+
+                // clear the partial string in the buffer;
+                _rxbuff.clear();
+            }
+            else if (rxoffset == _last_device_rxoffset)
+            {
+                // new data was added - refresh the portion of the cache that was updated
+                for (boost::uint32_t i = ((_last_device_rxoffset+1)/4) % poolsize; i != (((device_rxoffset)/4)+1) % poolsize; i = (i+1) % poolsize)
+                {
+                    _rxcache[i] = _iface->peek32(SR_ADDR(rxpool, i));
+                }
+            } else {
+                // there is new data, but we aren't done with what we have - check back later
+                break;
+            }
+
+            _last_device_rxoffset = device_rxoffset;
+
+            // check again to see if anything changed while we were updating the cache
+            device_rxoffset = _iface->peek32(SR_ADDR(X300_FW_SHMEM_BASE, X300_FW_SHMEM_UART_RX_INDEX));
+            delta = device_rxoffset - rxoffset;
         }
-        return -1;
     }
 
     std::string read_uart(double timeout)
     {
+        boost::mutex::scoped_lock(_read_mutex);
         const boost::system_time exit_time = boost::get_system_time() + boost::posix_time::microseconds(long(timeout*1e6));
         std::string buff;
+
         while (true)
         {
-            const int ch = this->getchar();
-            if (ch == -1)
+            // Update cache
+            this->update_cache();
+
+            // Get available characters
+            for (int ch = this->getchar(); ch != -1; ch = this->getchar())
             {
-                if (boost::get_system_time() > exit_time) break;
-                boost::this_thread::sleep(boost::posix_time::milliseconds(1));
-                continue;
+                // skip carriage returns
+                if (ch == '\r')
+                    continue;
+
+                // store character to buffer
+                _rxbuff += std::string(1, (char)ch);
+
+                // newline found - return string
+                if (ch == '\n')
+                {
+                    buff = _rxbuff;
+                    _rxbuff.clear();
+                    return buff;
+                }
             }
-            if (ch == '\r') continue;
-            buff += std::string(1, (char)ch);
-            if (ch == '\n') break;
+
+            // no more characters - check time
+            if (boost::get_system_time() > exit_time)
+                break;
         }
-        //UHD_VAR(buff);
+
         return buff;
     }
 
     wb_iface::sptr _iface;
     boost::uint32_t rxoffset, txoffset, txword32, rxpool, txpool, poolsize;
+    boost::uint32_t _last_device_rxoffset;
+    std::vector<boost::uint32_t> _rxcache;
+    std::string _rxbuff;
+    boost::mutex _read_mutex;
+    boost::mutex _write_mutex;
 };
 
 uart_iface::sptr x300_make_uart_iface(wb_iface::sptr iface)