GETC.cpp

00001 /*
00002     Copyright (c) 2010 Andy Kirkham
00003  
00004     Permission is hereby granted, free of charge, to any person obtaining a copy
00005     of this software and associated documentation files (the "Software"), to deal
00006     in the Software without restriction, including without limitation the rights
00007     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008     copies of the Software, and to permit persons to whom the Software is
00009     furnished to do so, subject to the following conditions:
00010  
00011     The above copyright notice and this permission notice shall be included in
00012     all copies or substantial portions of the Software.
00013  
00014     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020     THE SOFTWARE.
00021 */
00022 
00023 #include "MODSERIAL.h"
00024 #include "MACROS.h"
00025 
00026 namespace AjK {
00027 
00028 int 
00029 MODSERIAL::__getc(bool block)
00030 {
00031     // If no buffer is in use fall back to standard RX FIFO usage.
00032     // Note, we must block in this case and ignore bool "block" 
00033     // so as to maintain compat with Mbed Serial.
00034     if (buffer_size[RxIrq] == 0 || buffer[RxIrq] == (char *)NULL) {
00035         while(! MODSERIAL_READABLE ) ;
00036         return (int)(MODSERIAL_READ_REG & 0xFF);
00037     }
00038 
00039     if (block) { while ( MODSERIAL_RX_BUFFER_EMPTY ) ; } // Blocks.
00040     else if ( MODSERIAL_RX_BUFFER_EMPTY ) return -1;
00041     
00042     int c = buffer[RxIrq][buffer_out[RxIrq]];
00043     buffer_out[RxIrq]++;
00044     if (buffer_out[RxIrq] >= buffer_size[RxIrq]) {
00045         buffer_out[RxIrq] = 0;
00046     }
00047     
00048     // If we have made space in the RX Buffer then copy over
00049     // any characters in the RX FIFO that my reside there.
00050     // Temporarily disable the RX IRQ so that we do not re-enter 
00051     // it under interrupts.
00052     if ( ! MODSERIAL_RX_BUFFER_FULL ) {
00053         uint32_t irq_reg = MODSERIAL_IRQ_REG;
00054         DISABLE_RX_IRQ;
00055         isr_rx();    
00056         MODSERIAL_IRQ_REG = irq_reg;
00057     }
00058     
00059     __disable_irq();
00060     buffer_count[RxIrq]--;   
00061     __enable_irq();
00062     return c;
00063 }
00064 
00065 }; // namespace AjK ends
00066