diff options
Diffstat (limited to 'src-avr/ao_packet.c')
| -rw-r--r-- | src-avr/ao_packet.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src-avr/ao_packet.c b/src-avr/ao_packet.c new file mode 100644 index 00000000..f627e02b --- /dev/null +++ b/src-avr/ao_packet.c @@ -0,0 +1,148 @@ +/* + * 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) +{ + ao_led_on(AO_LED_RED); + /* If any tx data is pending then copy it into the tx packet */ + if (ao_packet_tx_used && ao_tx_packet.len == 0) { + memcpy(&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)); + ao_led_off(AO_LED_RED); +} + +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; + if (!(ao_rx_packet.status & PKT_APPEND_STATUS_1_CRC_OK)) + 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 + */ + memcpy(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++]; +} |