packet_parser.cpp

00001 #include "packet_parser.h"
00002 
00003 
00004 Thread* global_thread_ = NULL;
00005 
00006 void dma_complete_signal(MODSERIAL_IRQ_INFO *q) {
00007   if (global_thread_ != NULL) {
00008     global_thread_->signal_set(DMA_COMPLETE_FLAG);
00009   }
00010 }
00011 
00012 PacketParser::PacketParser(
00013   uint32_t baudrate, PinName tx_pin, PinName rx_pin, PinName tx_led, PinName rx_led) :
00014   pc_(tx_pin, rx_pin), /*dma_(),*/
00015   tx_led_(tx_led), send_thread_(&PacketParser::thread_starter, this),
00016   rx_led_(rx_led) {
00017   
00018   pc_.baud(baudrate);
00019   //pc_.MODDMA(&dma_);
00020   //pc_.attach_dmaSendComplete(this, &PacketParser::send_complete);
00021   //pc_.attach_dmaSendComplete(&dma_complete_signal);
00022   global_thread_ = &send_thread_;
00023 
00024   out_pkt_ = NULL;
00025   tx_sequence_ = 0;
00026 
00027   pc_.attach(this, &PacketParser::receive_callback, MODSERIAL::RxIrq);
00028   in_pkt_ = (packet_union_t*)in_box_.alloc();
00029   in_pkt_idx_ = 0;
00030   in_pkt_len_ = MAX_PACKET_LENGTH;
00031   in_pkt_crc_ = 0;
00032   
00033   send_thread_.signal_set(START_THREAD_FLAG);
00034 }
00035 
00036 packet_union_t* PacketParser::get_received_packet(void) {
00037   osEvent evt = in_box_.get(0);
00038   if (evt.status == osEventMail) {
00039     return (packet_union_t*)evt.value.p;
00040   } else {
00041     return NULL;
00042   }
00043 }
00044 
00045 void PacketParser::free_received_packet(packet_union_t* packet) {
00046   in_box_.free(packet);
00047 }
00048 
00049 packet_union_t* PacketParser::get_send_packet(void) {
00050   return (packet_union_t*)out_box_.alloc();
00051 }
00052 
00053 void PacketParser::send_packet(packet_union_t* packet) {
00054   out_box_.put(packet);
00055 }
00056 
00057 void PacketParser::thread_starter(void const *p) {
00058   PacketParser* instance = (PacketParser*)p;
00059   instance->send_worker();
00060 }
00061 
00062 void PacketParser::send_worker(void) {
00063   send_thread_.signal_wait(START_THREAD_FLAG);
00064   while(true) {
00065     osEvent evt = out_box_.get();
00066     if (evt.status == osEventMail) {
00067       tx_led_ = 1;
00068       out_pkt_ = (packet_union_t*)evt.value.p;
00069       out_pkt_->packet.header.start = 0;
00070       out_pkt_->packet.header.sequence = tx_sequence_++;
00071       uint8_t crc_value = calculate_crc8(out_pkt_->raw, out_pkt_->packet.header.length-1);
00072       out_pkt_->raw[out_pkt_->packet.header.length-1] = crc_value;
00073       //pc_.dmaSend(out_pkt_->raw, out_pkt_->packet.header.length);
00074       for (int i = 0; i < out_pkt_->packet.header.length; i++) {
00075         pc_.putc(out_pkt_->raw[i]);
00076       }
00077       tx_led_ = 0;
00078       send_thread_.signal_wait(DMA_COMPLETE_FLAG);
00079       tx_led_ = 1;
00080       send_thread_.signal_clr(DMA_COMPLETE_FLAG);
00081       out_box_.free(out_pkt_);
00082       out_pkt_ = NULL;
00083       tx_led_ = 0;
00084     }
00085     Thread::yield();
00086   }
00087 }
00088 
00089 void PacketParser::send_complete(MODSERIAL_IRQ_INFO *q) {
00090   tx_led_ = 1;
00091   if (out_pkt_ != NULL) {
00092     out_box_.free(out_pkt_);
00093     out_pkt_ = NULL;
00094   }
00095   tx_led_ = 0;
00096 }
00097 
00098 void PacketParser::receive_callback(MODSERIAL_IRQ_INFO *q) {
00099   rx_led_ = 1;
00100   MODSERIAL* serial = q->serial;
00101 
00102   if (in_pkt_ != NULL) {
00103     while(serial->readable()) {
00104       char c = serial->getc();
00105 
00106       // If we just received the second character, set packet length
00107       if (in_pkt_idx_ == 1) {
00108         in_pkt_len_ = c;
00109       }
00110 
00111       // If there has been a parse error, reset packet buffer
00112       if ((in_pkt_idx_ == 0 && c != 0) || in_pkt_len_ < sizeof(header_t)+1 ) {
00113         in_pkt_idx_ = 0;
00114         in_pkt_len_ = MAX_PACKET_LENGTH;
00115         in_pkt_crc_ = 0;
00116 
00117       // Store byte in packet buffer and update CRC
00118       } else {
00119         in_pkt_->raw[in_pkt_idx_++] = c;
00120         in_pkt_crc_ = update_crc8(in_pkt_crc_, c);
00121       }
00122 
00123       // If we just received the last character, put valid packets in mailbox
00124       // and reset packet buffer
00125       if (in_pkt_idx_ == in_pkt_len_) {
00126         if (in_pkt_crc_ == 0) {
00127           in_box_.put(in_pkt_);
00128           in_pkt_ = (packet_union_t*)in_box_.alloc();
00129         }
00130         in_pkt_idx_ = 0;
00131         in_pkt_len_ = MAX_PACKET_LENGTH;
00132         in_pkt_crc_ = 0;
00133       }
00134     }
00135   } else {
00136     in_pkt_ = (packet_union_t*)in_box_.alloc();
00137   }
00138 
00139   rx_led_ = 0;
00140 }