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/*
* Copyright © 2009 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "ao.h"
__xdata struct ao_packet_recv ao_rx_packet;
__xdata struct ao_packet ao_tx_packet;
__pdata uint8_t ao_packet_rx_len, ao_packet_rx_used, ao_packet_tx_used;
static __xdata char tx_data[AO_PACKET_MAX];
static __xdata char rx_data[AO_PACKET_MAX];
static __pdata uint8_t rx_seq;
__xdata struct ao_task ao_packet_task;
__xdata uint8_t ao_packet_enable;
__xdata uint8_t ao_packet_master_sleeping;
void
ao_packet_send(void)
{
#ifdef AO_LED_RED
ao_led_on(AO_LED_RED);
#endif
/* If any tx data is pending then copy it into the tx packet */
if (ao_packet_tx_used && ao_tx_packet.len == 0) {
ao_xmemcpy(&ao_tx_packet.d, tx_data, ao_packet_tx_used);
ao_tx_packet.len = ao_packet_tx_used;
ao_tx_packet.seq++;
ao_packet_tx_used = 0;
ao_wakeup(&tx_data);
}
ao_radio_send(&ao_tx_packet, sizeof (ao_tx_packet));
#ifdef AO_LED_RED
ao_led_off(AO_LED_RED);
#endif
}
uint8_t
ao_packet_recv(void)
{
uint8_t dma_done;
#ifdef AO_LED_GREEN
ao_led_on(AO_LED_GREEN);
#endif
dma_done = ao_radio_recv(&ao_rx_packet, sizeof (struct ao_packet_recv));
#ifdef AO_LED_GREEN
ao_led_off(AO_LED_GREEN);
#endif
/* Check to see if we got a valid packet */
if (!dma_done)
return 0;
#ifdef PKT_APPEND_STATUS_1_CRC_OK
if (!(ao_rx_packet.status & PKT_APPEND_STATUS_1_CRC_OK))
return 0;
#endif
/* Accept packets with matching call signs, or any packet if
* our callsign hasn't been configured
*/
if (ao_xmemcmp(ao_rx_packet.packet.callsign,
ao_config.callsign,
AO_MAX_CALLSIGN) != 0 &&
ao_xmemcmp(ao_config.callsign, CODE_TO_XDATA("N0CALL"), 7) != 0)
return 0;
/* SYN packets carry no data */
if (ao_rx_packet.packet.len == AO_PACKET_SYN) {
rx_seq = ao_rx_packet.packet.seq;
ao_tx_packet.seq = ao_rx_packet.packet.ack;
ao_tx_packet.ack = rx_seq;
} else if (ao_rx_packet.packet.len) {
/* Check for incoming data at the next sequence and
* for an empty data buffer
*/
if (ao_rx_packet.packet.seq == (uint8_t) (rx_seq + (uint8_t) 1) &&
ao_packet_rx_used == ao_packet_rx_len) {
/* Copy data to the receive data buffer and set up the
* offsets
*/
ao_xmemcpy(rx_data, ao_rx_packet.packet.d, ao_rx_packet.packet.len);
ao_packet_rx_used = 0;
ao_packet_rx_len = ao_rx_packet.packet.len;
/* Mark the sequence that we've received to
* let the sender know when we return a packet
*/
rx_seq = ao_rx_packet.packet.seq;
ao_tx_packet.ack = rx_seq;
/* Poke anyone looking for received data */
ao_wakeup(&ao_stdin_ready);
}
}
/* If the other side has seen the latest data we queued,
* wake up any task waiting to send data and let them go again
*/
if (ao_rx_packet.packet.ack == ao_tx_packet.seq) {
ao_tx_packet.len = 0;
ao_wakeup(&ao_tx_packet);
}
return 1;
}
#ifndef PACKET_HAS_MASTER
#define PACKET_HAS_MASTER 1
#endif
#if PACKET_HAS_MASTER
void
ao_packet_flush(void)
{
/* If there is data to send, and this is the master,
* then poke the master to send all queued data
*/
if (ao_packet_tx_used && ao_packet_master_sleeping)
ao_wakeup(&ao_packet_master_sleeping);
}
#endif /* PACKET_HAS_MASTER */
void
ao_packet_putchar(char c) __reentrant
{
while (ao_packet_tx_used == AO_PACKET_MAX && ao_packet_enable) {
#if PACKET_HAS_MASTER
ao_packet_flush();
#endif
ao_sleep(&tx_data);
}
if (ao_packet_enable)
tx_data[ao_packet_tx_used++] = c;
}
char
ao_packet_pollchar(void) __critical
{
if (!ao_packet_enable)
return AO_READ_AGAIN;
if (ao_packet_rx_used == ao_packet_rx_len)
return AO_READ_AGAIN;
return rx_data[ao_packet_rx_used++];
}
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