git.gag.com Git - fw/altos/blob - src/drivers/ao_packet.c

   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                 return 0;
  86
  87         /* Accept packets with matching call signs, or any packet if
  88          * our callsign hasn't been configured
  89          */
  90         if (ao_xmemcmp(ao_rx_packet.packet.callsign,
  91                        ao_config.callsign,
  92                        AO_MAX_CALLSIGN) != 0 &&
  93             ao_xmemcmp(ao_config.callsign, CODE_TO_XDATA("N0CALL"), 7) != 0)
  94                 return 0;
  95
  96         /* SYN packets carry no data */
  97         if (ao_rx_packet.packet.len == AO_PACKET_SYN) {
  98                 rx_seq = ao_rx_packet.packet.seq;
  99                 ao_tx_packet.seq = ao_rx_packet.packet.ack;
 100                 ao_tx_packet.ack = rx_seq;
 101         } else if (ao_rx_packet.packet.len) {
 102
 103                 /* Check for incoming data at the next sequence and
 104                  * for an empty data buffer
 105                  */
 106                 if ((ao_rx_packet.packet.seq == (uint8_t) (rx_seq + (uint8_t) 1) ||
 107                      ao_packet_restart) &&
 108                     ao_packet_rx_used == ao_packet_rx_len) {
 109
 110                         /* Copy data to the receive data buffer and set up the
 111                          * offsets
 112                          */
 113                         ao_xmemcpy(rx_data, ao_rx_packet.packet.d, ao_rx_packet.packet.len);
 114                         ao_packet_rx_used = 0;
 115                         ao_packet_rx_len = ao_rx_packet.packet.len;
 116
 117                         /* Mark the sequence that we've received to
 118                          * let the sender know when we return a packet
 119                          */
 120                         rx_seq = ao_rx_packet.packet.seq;
 121                         ao_tx_packet.ack = rx_seq;
 122
 123                         /* Poke anyone looking for received data */
 124                         ao_wakeup(&ao_stdin_ready);
 125                 }
 126         }
 127         ao_packet_restart = 0;
 128
 129         /* If the other side has seen the latest data we queued,
 130          * wake up any task waiting to send data and let them go again
 131          */
 132         if (ao_rx_packet.packet.ack == ao_tx_packet.seq) {
 133                 ao_tx_packet.len = 0;
 134                 ao_wakeup(&ao_tx_packet);
 135         }
 136         return 1;
 137 }
 138
 139 #if PACKET_HAS_MASTER
 140 void
 141 ao_packet_flush(void)
 142 {
 143         /* If there is data to send, and this is the master,
 144          * then poke the master to send all queued data
 145          */
 146         if (ao_packet_tx_used && ao_packet_master_sleeping)
 147                 ao_wakeup(&ao_packet_master_sleeping);
 148 }
 149 #endif /* PACKET_HAS_MASTER */
 150
 151 void
 152 ao_packet_putchar(char c) __reentrant
 153 {
 154         /* No need to block interrupts, all variables here
 155          * are only manipulated in task context
 156          */
 157         while (ao_packet_tx_used == AO_PACKET_MAX && ao_packet_enable) {
 158 #if PACKET_HAS_MASTER
 159                 ao_packet_flush();
 160 #endif
 161                 ao_sleep(&tx_data);
 162         }
 163
 164         if (ao_packet_enable)
 165                 tx_data[ao_packet_tx_used++] = c;
 166 }
 167
 168 /* May be called with interrupts blocked */
 169 int
 170 _ao_packet_pollchar(void)
 171 {
 172         if (!ao_packet_enable)
 173                 return AO_READ_AGAIN;
 174
 175         if (ao_packet_rx_used == ao_packet_rx_len)
 176                 return AO_READ_AGAIN;
 177
 178         return rx_data[ao_packet_rx_used++];
 179 }