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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 __xdata uint8_t ao_packet_last_rssi;
  35 #endif
  36
  37 void
  38 ao_packet_send(void)
  39 {
  40 #ifdef AO_LED_RED
  41         ao_led_on(AO_LED_RED);
  42 #endif
  43         /* If any tx data is pending then copy it into the tx packet */
  44         if (ao_packet_tx_used && ao_tx_packet.len == 0) {
  45                 ao_xmemcpy(&ao_tx_packet.d, tx_data, ao_packet_tx_used);
  46                 ao_tx_packet.len = ao_packet_tx_used;
  47                 ao_tx_packet.seq++;
  48                 ao_packet_tx_used = 0;
  49                 ao_wakeup(&tx_data);
  50         }
  51         ao_radio_send(&ao_tx_packet, sizeof (ao_tx_packet));
  52 #ifdef AO_LED_RED
  53         ao_led_off(AO_LED_RED);
  54 #endif
  55 }
  56
  57 uint8_t
  58 ao_packet_recv(void)
  59 {
  60         uint8_t dma_done;
  61
  62 #ifdef AO_LED_GREEN
  63         ao_led_on(AO_LED_GREEN);
  64 #endif
  65         dma_done = ao_radio_recv(&ao_rx_packet, sizeof (struct ao_packet_recv));
  66 #ifdef AO_LED_GREEN
  67         ao_led_off(AO_LED_GREEN);
  68 #endif
  69 #if AO_PROFILE
  70                 {
  71                         extern uint32_t ao_rx_start_tick, ao_rx_packet_tick, ao_rx_done_tick, ao_rx_last_done_tick;
  72                         extern uint32_t ao_fec_decode_start, ao_fec_decode_end;
  73
  74                         printf ("between packet: %d\n", ao_rx_start_tick - ao_rx_last_done_tick);
  75                         printf ("receive start delay: %d\n", ao_rx_packet_tick - ao_rx_start_tick);
  76                         printf ("decode time: %d\n", ao_fec_decode_end - ao_fec_decode_start);
  77                         printf ("rx cleanup: %d\n\n", ao_rx_done_tick - ao_fec_decode_end);
  78                         flush();
  79                 }
  80 #endif
  81
  82         /* Check to see if we got a valid packet */
  83         if (!dma_done)
  84                 return 0;
  85         if (!(ao_rx_packet.status & AO_RADIO_STATUS_CRC_OK))
  86                 return 0;
  87
  88 #if PACKET_HAS_MASTER
  89         ao_packet_last_rssi = ao_rx_packet.rssi;
  90 #endif
  91         /* Accept packets with matching call signs, or any packet if
  92          * our callsign hasn't been configured
  93          */
  94         if (ao_xmemcmp(ao_rx_packet.packet.callsign,
  95                        ao_config.callsign,
  96                        AO_MAX_CALLSIGN) != 0 &&
  97             ao_xmemcmp(ao_config.callsign, CODE_TO_XDATA("N0CALL"), 7) != 0)
  98                 return 0;
  99
 100         /* SYN packets carry no data */
 101         if (ao_rx_packet.packet.len == AO_PACKET_SYN) {
 102                 rx_seq = ao_rx_packet.packet.seq;
 103                 ao_tx_packet.seq = ao_rx_packet.packet.ack;
 104                 ao_tx_packet.ack = rx_seq;
 105         } else if (ao_rx_packet.packet.len) {
 106
 107                 /* Check for incoming data at the next sequence and
 108                  * for an empty data buffer
 109                  */
 110                 if ((ao_rx_packet.packet.seq == (uint8_t) (rx_seq + (uint8_t) 1) ||
 111                      ao_packet_restart) &&
 112                     ao_packet_rx_used == ao_packet_rx_len) {
 113
 114                         /* Copy data to the receive data buffer and set up the
 115                          * offsets
 116                          */
 117                         ao_xmemcpy(rx_data, ao_rx_packet.packet.d, ao_rx_packet.packet.len);
 118                         ao_packet_rx_used = 0;
 119                         ao_packet_rx_len = ao_rx_packet.packet.len;
 120
 121                         /* Mark the sequence that we've received to
 122                          * let the sender know when we return a packet
 123                          */
 124                         rx_seq = ao_rx_packet.packet.seq;
 125                         ao_tx_packet.ack = rx_seq;
 126
 127                         /* Poke anyone looking for received data */
 128                         ao_wakeup(&ao_stdin_ready);
 129                 }
 130         }
 131         ao_packet_restart = 0;
 132
 133         /* If the other side has seen the latest data we queued,
 134          * wake up any task waiting to send data and let them go again
 135          */
 136         if (ao_rx_packet.packet.ack == ao_tx_packet.seq) {
 137                 ao_tx_packet.len = 0;
 138                 ao_wakeup(&ao_tx_packet);
 139         }
 140         return 1;
 141 }
 142
 143 #if PACKET_HAS_MASTER
 144 void
 145 ao_packet_flush(void)
 146 {
 147         /* If there is data to send, and this is the master,
 148          * then poke the master to send all queued data
 149          */
 150         if (ao_packet_tx_used && ao_packet_master_sleeping)
 151                 ao_wakeup(&ao_packet_master_sleeping);
 152 }
 153 #endif /* PACKET_HAS_MASTER */
 154
 155 void
 156 ao_packet_putchar(char c) __reentrant
 157 {
 158         /* No need to block interrupts, all variables here
 159          * are only manipulated in task context
 160          */
 161         while (ao_packet_tx_used == AO_PACKET_MAX && ao_packet_enable) {
 162 #if PACKET_HAS_MASTER
 163                 ao_packet_flush();
 164 #endif
 165                 ao_sleep(&tx_data);
 166         }
 167
 168         if (ao_packet_enable)
 169                 tx_data[ao_packet_tx_used++] = c;
 170 }
 171
 172 int
 173 ao_packet_pollchar(void)
 174 {
 175         /* No need to block interrupts, all variables here
 176          * are only manipulated in task context
 177          */
 178         if (!ao_packet_enable)
 179                 return AO_READ_AGAIN;
 180
 181         if (ao_packet_rx_used == ao_packet_rx_len)
 182                 return AO_READ_AGAIN;
 183
 184         return rx_data[ao_packet_rx_used++];
 185 }