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   1 /*
   2  * Copyright © 2009 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include "ao.h"
  19
  20 __xdata struct ao_packet_recv ao_rx_packet;
  21 __xdata struct ao_packet ao_tx_packet;
  22 __pdata uint8_t ao_packet_rx_len, ao_packet_rx_used, ao_packet_tx_used;
  23
  24 static __xdata uint8_t tx_data[AO_PACKET_MAX];
  25 static __xdata uint8_t rx_data[AO_PACKET_MAX];
  26 static __pdata uint8_t rx_seq;
  27
  28 __xdata struct ao_task  ao_packet_task;
  29 __xdata uint8_t ao_packet_enable;
  30 __xdata uint8_t ao_packet_restart;
  31
  32 #if PACKET_HAS_MASTER
  33 __xdata uint8_t ao_packet_master_sleeping;
  34 #endif
  35
  36 void
  37 ao_packet_send(void)
  38 {
  39 #ifdef AO_LED_RED
  40         ao_led_on(AO_LED_RED);
  41 #endif
  42         /* If any tx data is pending then copy it into the tx packet */
  43         if (ao_packet_tx_used && ao_tx_packet.len == 0) {
  44                 ao_xmemcpy(&ao_tx_packet.d, tx_data, ao_packet_tx_used);
  45                 ao_tx_packet.len = ao_packet_tx_used;
  46                 ao_tx_packet.seq++;
  47                 ao_packet_tx_used = 0;
  48                 ao_wakeup(&tx_data);
  49         }
  50         ao_radio_send(&ao_tx_packet, sizeof (ao_tx_packet));
  51 #ifdef AO_LED_RED
  52         ao_led_off(AO_LED_RED);
  53 #endif
  54 }
  55
  56 uint8_t
  57 ao_packet_recv(uint16_t timeout)
  58 {
  59         uint8_t dma_done;
  60
  61 #ifdef AO_LED_GREEN
  62         ao_led_on(AO_LED_GREEN);
  63 #endif
  64         dma_done = ao_radio_recv(&ao_rx_packet, sizeof (struct ao_packet_recv), timeout);
  65 #ifdef AO_LED_GREEN
  66         ao_led_off(AO_LED_GREEN);
  67 #endif
  68 #if AO_PROFILE
  69                 {
  70                         extern uint32_t ao_rx_start_tick, ao_rx_packet_tick, ao_rx_done_tick, ao_rx_last_done_tick;
  71                         extern uint32_t ao_fec_decode_start, ao_fec_decode_end;
  72
  73                         printf ("between packet: %d\n", ao_rx_start_tick - ao_rx_last_done_tick);
  74                         printf ("receive start delay: %d\n", ao_rx_packet_tick - ao_rx_start_tick);
  75                         printf ("decode time: %d\n", ao_fec_decode_end - ao_fec_decode_start);
  76                         printf ("rx cleanup: %d\n\n", ao_rx_done_tick - ao_fec_decode_end);
  77                         flush();
  78                 }
  79 #endif
  80
  81         /* Check to see if we got a valid packet */
  82         if (!dma_done)
  83                 return 0;
  84         if (!(ao_rx_packet.status & AO_RADIO_STATUS_CRC_OK)) {
  85                 printf("bad crc addr %d len %d seq %d ack %d callsign %8.8s\n",
  86                         ao_rx_packet.packet.addr,
  87                         ao_rx_packet.packet.len,
  88                         ao_rx_packet.packet.seq,
  89                         ao_rx_packet.packet.ack,
  90                         ao_rx_packet.packet.callsign);
  91                 flush();
  92                 return 0;
  93         }
  94
  95         /* Accept packets with matching call signs, or any packet if
  96          * our callsign hasn't been configured
  97          */
  98         if (ao_xmemcmp(ao_rx_packet.packet.callsign,
  99                        ao_config.callsign,
 100                        AO_MAX_CALLSIGN) != 0 &&
 101             ao_xmemcmp(ao_config.callsign, CODE_TO_XDATA("N0CALL"), 7) != 0) {
 102                 printf ("bad call\n"); flush();
 103                 return 0;
 104         }
 105
 106         /* SYN packets carry no data */
 107         if (ao_rx_packet.packet.len == AO_PACKET_SYN) {
 108                 rx_seq = ao_rx_packet.packet.seq;
 109                 ao_tx_packet.seq = ao_rx_packet.packet.ack;
 110                 ao_tx_packet.ack = rx_seq;
 111         } else if (ao_rx_packet.packet.len) {
 112
 113                 /* Check for incoming data at the next sequence and
 114                  * for an empty data buffer
 115                  */
 116                 if ((ao_rx_packet.packet.seq == (uint8_t) (rx_seq + (uint8_t) 1) ||
 117                      ao_packet_restart) &&
 118                     ao_packet_rx_used == ao_packet_rx_len) {
 119
 120                         /* Copy data to the receive data buffer and set up the
 121                          * offsets
 122                          */
 123                         ao_xmemcpy(rx_data, ao_rx_packet.packet.d, ao_rx_packet.packet.len);
 124                         ao_packet_rx_used = 0;
 125                         ao_packet_rx_len = ao_rx_packet.packet.len;
 126
 127                         /* Mark the sequence that we've received to
 128                          * let the sender know when we return a packet
 129                          */
 130                         rx_seq = ao_rx_packet.packet.seq;
 131                         ao_tx_packet.ack = rx_seq;
 132
 133                         /* Poke anyone looking for received data */
 134                         ao_wakeup(&ao_stdin_ready);
 135                 }
 136         }
 137         ao_packet_restart = 0;
 138
 139         /* If the other side has seen the latest data we queued,
 140          * wake up any task waiting to send data and let them go again
 141          */
 142         if (ao_rx_packet.packet.ack == ao_tx_packet.seq) {
 143                 ao_tx_packet.len = 0;
 144                 ao_wakeup(&ao_tx_packet);
 145         }
 146         return 1;
 147 }
 148
 149 #if PACKET_HAS_MASTER
 150 void
 151 ao_packet_flush(void)
 152 {
 153         /* If there is data to send, and this is the master,
 154          * then poke the master to send all queued data
 155          */
 156         if (ao_packet_tx_used && ao_packet_master_sleeping)
 157                 ao_wakeup(&ao_packet_master_sleeping);
 158 }
 159 #endif /* PACKET_HAS_MASTER */
 160
 161 void
 162 ao_packet_putchar(char c) __reentrant
 163 {
 164         /* No need to block interrupts, all variables here
 165          * are only manipulated in task context
 166          */
 167         while (ao_packet_tx_used == AO_PACKET_MAX && ao_packet_enable) {
 168 #if PACKET_HAS_MASTER
 169                 ao_packet_flush();
 170 #endif
 171                 ao_sleep(&tx_data);
 172         }
 173
 174         if (ao_packet_enable)
 175                 tx_data[ao_packet_tx_used++] = c;
 176 }
 177
 178 /* May be called with interrupts blocked */
 179 int
 180 _ao_packet_pollchar(void)
 181 {
 182         if (!ao_packet_enable)
 183                 return AO_READ_AGAIN;
 184
 185         if (ao_packet_rx_used == ao_packet_rx_len)
 186                 return AO_READ_AGAIN;
 187
 188         return rx_data[ao_packet_rx_used++];
 189 }