Diff: MODSERIAL/PUTC.cpp

Revision:

0:afb2650fb49a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MODSERIAL/PUTC.cpp	Mon Feb 13 02:11:20 2012 +0000
@@ -0,0 +1,79 @@
+/*
+    Copyright (c) 2010 Andy Kirkham
+ 
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+ 
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+ 
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+*/
+
+#include "MODSERIAL.h"
+#include "MACROS.h"
+
+namespace AjK {
+
+int
+MODSERIAL::__putc(int c, bool block) {
+    
+    // If no buffer is in use fall back to standard TX FIFO usage.
+    // Note, we must block in this case and ignore bool "block" 
+    // so as to maintain compat with Mbed Serial.
+    if (buffer[TxIrq] == (char *)NULL || buffer_size[TxIrq] == 0) {
+        while (! MODSERIAL_THR_HAS_SPACE) ; // Wait for space in the TX FIFO.
+        _THR = (uint32_t)c;
+        return 0;
+    }
+    
+    if ( MODSERIAL_THR_HAS_SPACE && MODSERIAL_TX_BUFFER_EMPTY && dmaSendChannel == -1 ) {
+        _THR = (uint32_t)c;
+    }
+    else {
+        if (block) {
+            uint32_t ier = _IER; _IER = 1;
+            while ( MODSERIAL_TX_BUFFER_FULL ) {  // Blocks!
+                // If putc() is called from an ISR then we are stuffed
+                // because in an ISR no bytes from the TX buffer will 
+                // get transferred to teh TX FIFOs while we block here.
+                // So, to work around this, instead of sitting in a 
+                // loop waiting for space in the TX buffer (which will
+                // never happen in IRQ context), check to see if the
+                // TX FIFO has space available to move bytes from the
+                // TX buffer to TX FIFO to make space. The easiest way
+                // to do this is to poll the isr_tx() function while we
+                // are blocking.
+                isr_tx(false);
+            }
+            _IER = ier;
+        }
+        else if( MODSERIAL_TX_BUFFER_FULL ) {
+            buffer_overflow[TxIrq] = c; // Oh dear, no room in buffer.
+            _isr[TxOvIrq].call(&this->callbackInfo);
+            return -1;
+        }
+        _IER &= ~2;
+        buffer[TxIrq][buffer_in[TxIrq]] = c;
+        buffer_count[TxIrq]++;
+        buffer_in[TxIrq]++;
+        if (buffer_in[TxIrq] >= buffer_size[TxIrq]) {
+            buffer_in[TxIrq] = 0;
+        }            
+        _IER |= 2;        
+    }
+      
+    return 0;
+}
+
+}; // namespace AjK ends