altos: Starting to write cc1120 driver

[fw/altos] / src / drivers / ao_packet.c

diff --git a/src/drivers/ao_packet.c b/src/drivers/ao_packet.c
new file mode 100644 (file)
index 0000000..19fe055
--- /dev/null
+++ b/src/drivers/ao_packet.c
@@ -0,0 +1,163 @@
+/*
+ * 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++];
+}