680 lines
16 KiB
C
680 lines
16 KiB
C
/*
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* Copyright (c) 2005, Swedish Institute of Computer Science
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This file is part of the Contiki operating system.
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*
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* @(#)$Id: cc2420.c,v 1.1 2006/06/17 22:41:16 adamdunkels Exp $
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*/
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/*
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* This code is almost device independent and should be possible to
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* port to the AVR.
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*/
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#include <stdio.h>
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#include <string.h>
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#include <io.h>
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#include <signal.h>
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#include "contiki.h"
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#include "sys/clock.h"
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#include "net/uip.h"
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#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
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#include "dev/leds.h"
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#include "dev/spi.h"
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#include "dev/cc2420.h"
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#include "dev/cc2420_const.h"
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PROCESS(cc2420_process, "CC2420 driver");
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PROCESS(cc2420_retransmit_process, "CC2420 retransmit process");
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int cc2420_resend(void); /* Not yet exported. */
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static void neigbour_update(u16_t mac, int retransmissions);
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signed char cc2420_last_rssi;
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u8_t cc2420_last_correlation;
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static u8_t receive_on;
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volatile u8_t cc2420_ack_received; /* Naive ACK management. */
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static u8_t last_used_seq;
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static u16_t last_correspondent;
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/* Radio stuff in network byte order. */
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static u16_t pan_id;
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unsigned
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cc2420_getreg(enum cc2420_register regname)
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{
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unsigned reg;
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int s = splhigh();
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FASTSPI_GETREG(regname, reg);
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splx(s);
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return reg;
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}
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void
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cc2420_setreg(enum cc2420_register regname, unsigned value)
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{
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int s = splhigh();
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FASTSPI_SETREG(regname, value);
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splx(s);
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}
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void
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cc2420_strobe(enum cc2420_register regname)
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{
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int s = splhigh();
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FASTSPI_STROBE(regname);
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splx(s);
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}
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unsigned
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cc2420_status(void)
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{
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u8_t status;
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int s = splhigh();
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FASTSPI_UPD_STATUS(status);
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splx(s);
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return status;
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}
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#define PA_LEVEL 0x1F
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unsigned
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cc2420_pa_level(u16_t p)
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{
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u16_t reg;
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/*
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* All PA settings can be used, the ones given in the datasheet
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* correspond to 0, -1, -3, -5, -7, -10, -15, -25 dBm in the
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* reference design.
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*/
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if (p > PA_LEVEL)
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p = PA_LEVEL;
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reg = cc2420_getreg(CC2420_TXCTRL);
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p |= reg & ~PA_LEVEL;
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cc2420_setreg(CC2420_TXCTRL, p);
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return reg & PA_LEVEL;
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}
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unsigned
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cc2420_get_pa_level(void)
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{
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u16_t reg;
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reg = cc2420_getreg(CC2420_TXCTRL);
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return reg & PA_LEVEL;
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}
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int
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cc2420_get_current_rssi(void)
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{
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u16_t reg;
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reg = cc2420_getreg(CC2420_RSSI);
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return (signed char) (reg & 0xff);
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}
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#define AUTOACK (1 << 4)
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#define RXFIFO_PROTECTION (1 << 9)
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#define CORR_THR(n) (((n) & 0x1f) << 6)
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#define FIFOP_THR(n) ((n) & 0x7f)
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void
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cc2420_init(void)
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{
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u16_t reg;
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{
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int s = splhigh();
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__cc2420_arch_init(); /* Initalize ports and SPI. */
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DISABLE_FIFOP_INT();
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FIFOP_INT_INIT();
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splx(s);
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}
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/* Turn on voltage regulator and reset. */
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SET_VREG_ACTIVE();
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//clock_delay(250); OK
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SET_RESET_ACTIVE();
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clock_delay(127);
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SET_RESET_INACTIVE();
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//clock_delay(125); OK
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/* Turn on the crystal oscillator. */
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cc2420_strobe(CC2420_SXOSCON);
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/* Turn on automatic packet acknowledgment. */
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reg = cc2420_getreg(CC2420_MDMCTRL0);
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reg |= AUTOACK;
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cc2420_setreg(CC2420_MDMCTRL0, reg);
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/* Set the correlation threshold = 20. */
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cc2420_setreg(CC2420_MDMCTRL1, CORR_THR(20));
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/* Set the FIFOP threshold to maximum. */
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cc2420_setreg(CC2420_IOCFG0, FIFOP_THR(127));
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/* Turn off "Security enable" (page 32). */
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reg = cc2420_getreg(CC2420_SECCTRL0);
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reg &= ~RXFIFO_PROTECTION;
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cc2420_setreg(CC2420_SECCTRL0, reg);
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cc2420_set_chan_pan_addr(11, 0xffff, 0x0000, NULL);
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}
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int
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cc2420_send_data_ack(u16_t mac)
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{
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struct hdr_802_15 h;
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h.len = MAC_HDR_LEN + 2; /* Including footer[2]. */
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h.fc0 = FC0_TYPE_DATA | FC0_INTRA_PAN;
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h.fc1 = FC1_DST_16 | FC1_SRC_16;
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h.src = uip_hostaddr[1];
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h.dst = mac;
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cc2420_send(&h, 10, NULL, 0);
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return 0;
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}
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int
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cc2420_send(struct hdr_802_15 *hdr, u8_t hdr_len,
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const u8_t *payload, u8_t payload_len)
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{
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u8_t spiStatusByte;
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int s;
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/* struct hdr_802_15::len shall *not* be counted, thus the -1.
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* 2 == sizeof(footer).
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*/
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if (((hdr_len - 1) + payload_len + 2) > MAX_PACKET_LEN)
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return -1;
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/* This code uses the CC2420 CCA (Clear Channel Assessment) to
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* implement Carrier Sense Multiple Access with Collision Avoidance
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* (CSMA-CA) and requires the receiver to be enabled and ready.
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*/
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if (!receive_on)
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return -2;
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/* Wait for previous transmission to finish and RSSI. */
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do {
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spiStatusByte = cc2420_status();
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if (!(spiStatusByte & BV(CC2420_RSSI_VALID))) /* RSSI needed by CCA */
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continue;
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} while (spiStatusByte & BV(CC2420_TX_ACTIVE));
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hdr->dst_pan = pan_id; /* Not at fixed position! xxx/bg */
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last_correspondent = hdr->dst; /* Not dst either. */
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last_used_seq++;
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hdr->seq = last_used_seq;
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cc2420_ack_received = 0;
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/* Write packet to TX FIFO, appending FCS if AUTOCRC is enabled. */
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cc2420_strobe(CC2420_SFLUSHTX); /* Cancel send that never started. */
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s = splhigh();
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FASTSPI_WRITE_FIFO(hdr, hdr_len);
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FASTSPI_WRITE_FIFO(payload, payload_len);
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splx(s);
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if (hdr->dst != 0xffff)
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process_post(&cc2420_retransmit_process,
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PROCESS_EVENT_MSG,
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(void *)(unsigned)last_used_seq);
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return cc2420_resend(); /* Send stuff from FIFO. */
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}
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int
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cc2420_resend(void)
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{
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int i;
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/* Request packet to be sent using CSMA-CA. */
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cc2420_strobe(CC2420_STXONCCA);
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/* The RX FIFO can only hold one packet! Make sure to not overrun
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* FIFO by waiting for transmission to start here and synchronizing
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* with the CC2420_TX_ACTIVE check in cc2420_send.
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*
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* If RX FIFO is full or CSMA-CA never says ok we will have to
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* terminate the loop below before SFD_IS_1!
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*/
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for (i = 0; i < 1000; i++)
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if (SFD_IS_1)
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return 0; /* Transmission has started. */
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/*
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* In the exceptional case that transmission never occurred we try
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* again but never verify if the transmission ever starts. If a new
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* call to cc2420_send() happens in a near future this transmission
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* will be permanently canceled.
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*/
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cc2420_strobe(CC2420_STXONCCA);
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return 0;
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}
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void
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cc2420_off(void)
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{
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u8_t spiStatusByte;
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if (receive_on == 0)
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return;
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receive_on = 0;
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/* Wait for transmission to end before turning radio off. */
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do {
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spiStatusByte = cc2420_status();
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} while (spiStatusByte & BV(CC2420_TX_ACTIVE));
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cc2420_strobe(CC2420_SRFOFF);
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DISABLE_FIFOP_INT();
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}
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void
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cc2420_on(void)
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{
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if (receive_on)
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return;
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receive_on = 1;
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cc2420_strobe(CC2420_SRXON);
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cc2420_strobe(CC2420_SFLUSHRX);
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ENABLE_FIFOP_INT();
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}
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void
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cc2420_set_chan_pan_addr(unsigned channel, unsigned pan,
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unsigned addr, const u8_t *ieee_addr)
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{
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/*
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* Subtract the base channel (11), multiply by 5, which is the
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* channel spacing. 357 is 2405-2048 and 0x4000 is LOCK_THR = 1.
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*/
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u8_t spiStatusByte;
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u16_t f = channel;
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int s;
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f = 5*(f - 11) + 357 + 0x4000;
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/*
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* Writing RAM requires crystal oscillator to be stable.
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*/
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do {
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spiStatusByte = cc2420_status();
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} while (!(spiStatusByte & (BV(CC2420_XOSC16M_STABLE))));
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pan_id = pan;
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cc2420_setreg(CC2420_FSCTRL, f);
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s = splhigh();
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FASTSPI_WRITE_RAM_LE(&pan, CC2420RAM_PANID, 2, f);
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FASTSPI_WRITE_RAM_LE(&addr, CC2420RAM_SHORTADDR, 2, f);
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if (ieee_addr != NULL)
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FASTSPI_WRITE_RAM_LE(ieee_addr, CC2420RAM_IEEEADDR, 8, f);
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splx(s);
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}
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static volatile u8_t rx_fifo_remaining_bytes;
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static struct hdr_802_15 h;
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/*
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* Interrupt either leaves frame intact in FIFO or reads *only* the
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* MAC header and sets rx_fifo_remaining_bytes.
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*
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* In order to quickly empty the FIFO ack processing is done at
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* interrupt priority rather than poll priority.
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*/
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int
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__cc2420_intr(void)
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{
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u8_t length;
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const u8_t *const ack_footer = (u8_t *)&h.dst_pan;
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CLEAR_FIFOP_INT();
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if (spi_busy || rx_fifo_remaining_bytes > 0) {
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/* SPI bus hardware is currently used elsewhere (UART0 or I2C bus)
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* or we already have a packet in the works and will have to defer
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* interrupt processing of this packet in a fake interrupt.
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*/
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process_poll(&cc2420_process);
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return 1;
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}
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FASTSPI_READ_FIFO_BYTE(length);
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if (length > MAX_PACKET_LEN) {
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/* Oops, we must be out of sync. */
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//printf("__cc2420_intr out of sync\n");
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FASTSPI_STROBE(CC2420_SFLUSHRX);
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FASTSPI_STROBE(CC2420_SFLUSHRX);
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return 0;
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}
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h.len = length;
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if (length < ACK_PACKET_LEN) {
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FASTSPI_READ_FIFO_GARBAGE(length); /* Rubbish */
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return 0;
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}
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FASTSPI_READ_FIFO_NO_WAIT(&h.fc0, 5); /* fc0, fc1, seq, dst_pan */
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/* Is this an ACK packet? */
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if (length == ACK_PACKET_LEN && (h.fc0 & FC0_TYPE_MASK) == FC0_TYPE_ACK) {
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if (ack_footer[1] & FOOTER1_CRC_OK) {
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if (h.seq == last_used_seq) { /* Matching ACK number? */
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cc2420_ack_received = 1;
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process_poll(&cc2420_retransmit_process);
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#if 0
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cc2420_last_rssi = ack_footer[0];
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cc2420_last_correlation = ack_footer[1] & FOOTER1_CORRELATION;
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#endif
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}
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}
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return 1;
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}
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if (length < (MAC_HDR_LEN + 2)) {
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FASTSPI_READ_FIFO_GARBAGE(length - 5);
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return 0;
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}
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FASTSPI_READ_FIFO_NO_WAIT(&h.dst, 4); /* dst and src */
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/* The payload and footer is now left in the RX FIFO and will be
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* picked up asynchronously at poll priority in the cc2420_process
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* below.
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*/
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rx_fifo_remaining_bytes = length - MAC_HDR_LEN;
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process_poll(&cc2420_process);
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return 1;
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}
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PROCESS_THREAD(cc2420_process, ev, data)
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{
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PROCESS_BEGIN();
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process_start(&cc2420_retransmit_process, NULL);
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while (1) {
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unsigned len;
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int s;
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PROCESS_YIELD();
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len = rx_fifo_remaining_bytes;
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if (len > 0) {
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/* Read payload and two bytes of footer */
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if ((len - 2) > (UIP_BUFSIZE - UIP_LLH_LEN) || len < 2) {
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printf("cc2420_process too big len=%d\n", len);
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s = splhigh();
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FASTSPI_READ_FIFO_GARBAGE(len);
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rx_fifo_remaining_bytes = 0; /* RX FIFO emptied! */
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splx(s);
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len = 0;
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} else {
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u8_t footer[2];
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uip_len = 0;
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s = splhigh();
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FASTSPI_READ_FIFO_NO_WAIT(&uip_buf[UIP_LLH_LEN], len - 2);
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FASTSPI_READ_FIFO_NO_WAIT(footer, 2);
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rx_fifo_remaining_bytes = 0; /* RX FIFO emptied! */
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splx(s);
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if (footer[1] & FOOTER1_CRC_OK) {
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cc2420_last_rssi = footer[0];
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cc2420_last_correlation = footer[1] & FOOTER1_CORRELATION;
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if ((h.fc0 & FC0_TYPE_MASK) == FC0_TYPE_DATA)
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uip_len = len - 2;
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}
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}
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}
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/* Clean up in case of FIFO overflow! This happens for every full
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* length frame and is signaled by FIFOP = 1 and FIFO = 0.
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*/
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if (FIFOP_IS_1 && !FIFO_IS_1) {
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cc2420_strobe(CC2420_SFLUSHRX);
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cc2420_strobe(CC2420_SFLUSHRX);
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}
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if (FIFOP_IS_1) {
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s = splhigh();
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__cc2420_intr(); /* Fake interrupt! */
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splx(s);
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}
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if (len == 2) { /* A DATA ACK packet. */
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if (last_correspondent == h.src)
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cc2420_ack_received = 1;
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neigbour_update(h.src, 0);
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} else if (len > 2 && uip_len > 0
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&& uip_len == (((u16_t)(BUF->len[0]) << 8) + BUF->len[1])) {
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/*
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* If we are the unique receiver send DATA ACK.
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*/
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if (h.dst == 0xffff
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&& BUF->destipaddr[0] == uip_hostaddr[0]
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&& BUF->destipaddr[1] == uip_hostaddr[1])
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cc2420_send_data_ack(h.src);
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leds_toggle(LEDS_GREEN);
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tcpip_input();
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leds_toggle(LEDS_GREEN);
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}
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}
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PROCESS_END();
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}
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unsigned neigbour_find(u16_t mac);
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/* Must be atleast 2 ticks and larger than 4ms. */
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#define RETRANSMIT_TIMEOUT 2 /* 31.25ms @ 64Hz */
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#define MAX_RETRANSMISSIONS 3
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PROCESS_THREAD(cc2420_retransmit_process, ev, data)
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{
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static u8_t seq, n;
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static struct etimer etimer;
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PROCESS_BEGIN();
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while (1) {
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PROCESS_WAIT_UNTIL(ev == PROCESS_EVENT_MSG);
|
|
seq = (unsigned)data;
|
|
|
|
n = 0;
|
|
do {
|
|
etimer_set(&etimer, RETRANSMIT_TIMEOUT);
|
|
PROCESS_WAIT_UNTIL(etimer_expired(&etimer) || ev == PROCESS_EVENT_POLL);
|
|
if (ev == PROCESS_EVENT_POLL) {
|
|
etimer_stop(&etimer);
|
|
break;
|
|
} else if (seq != last_used_seq)
|
|
break; /* Transmitting different packet. */
|
|
else if (n < MAX_RETRANSMISSIONS) {
|
|
cc2420_resend();
|
|
n++;
|
|
} else {
|
|
break;
|
|
}
|
|
} while (1);
|
|
neigbour_update(last_correspondent, n);
|
|
#if 0
|
|
#define CORRELATION_2_X(c) (((c) < 48) ? 0 : ((c) - 48))
|
|
printf("%04x %2d %2d %2u %u\n",
|
|
last_correspondent, n,
|
|
RSSI_2_ED(cc2420_last_rssi),
|
|
CORRELATION_2_X(cc2420_last_correlation),
|
|
clock_time());
|
|
#endif
|
|
}
|
|
|
|
PROCESS_END();
|
|
}
|
|
|
|
/*
|
|
* Retransmissions are negexp(alfa=0.5) weighted and stored as 4-bit
|
|
* fixnums with 2 binals (binary decimals).
|
|
*/
|
|
#define SCALE_RETRANS 4
|
|
#define SCALE_RETRANS_THRESHOLD (3*4)
|
|
#define MAX_SCALE_RETRANS 15
|
|
|
|
/*
|
|
* Expiration timestamps are 4-bits wide, in units of 4 seconds, and
|
|
* relative to cc2420_check_remote::toff.
|
|
*/
|
|
#define SCALE_DIV_EXPIRE 4
|
|
#define MAX_EXPIRE 15
|
|
#define AGE_INTERVAL 5 /* 20 seconds */
|
|
|
|
struct cc2420_neigbour {
|
|
unsigned mac:16, nretrans:4, expire:4; /* expiration time */
|
|
#if 0
|
|
unsigned rssi:6, correlation:6;
|
|
#endif
|
|
};
|
|
|
|
#define NNEIGBOURS 16
|
|
static struct cc2420_neigbour neigbours[NNEIGBOURS];
|
|
|
|
/*
|
|
* Double hash into 3 different positions using a constand step. If we
|
|
* don't find a match, return a pointer to the oldest entry and use
|
|
* this position for insertion.
|
|
*/
|
|
static struct cc2420_neigbour *
|
|
lookup(unsigned mac)
|
|
{
|
|
unsigned h = (mac + (mac>>8)) % NNEIGBOURS;
|
|
#define next(h) (h += step, (h >= NNEIGBOURS) ? (h - NNEIGBOURS) : h)
|
|
|
|
if (neigbours[h].mac == mac) /* FOUND1 */
|
|
return &neigbours[h];
|
|
else {
|
|
unsigned minexp = h;
|
|
const unsigned step = ((mac>>9)&0x3) + 1;
|
|
|
|
h = next(h);
|
|
if (neigbours[h].mac == mac) /* FOUND2 */
|
|
return &neigbours[h];
|
|
else {
|
|
if (neigbours[h].expire < neigbours[minexp].expire) minexp = h;
|
|
h = next(h);
|
|
if (neigbours[h].mac == mac) /* FOUND3 */
|
|
return &neigbours[h];
|
|
else {
|
|
if (neigbours[h].expire < neigbours[minexp].expire) minexp = h;
|
|
return &neigbours[minexp];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
neigbour_update(u16_t mac, int nretrans)
|
|
{
|
|
struct cc2420_neigbour *t;
|
|
|
|
/* Always scale nretrans by constant factor. */
|
|
if (nretrans == MAX_RETRANSMISSIONS)
|
|
nretrans = MAX_SCALE_RETRANS;
|
|
else
|
|
nretrans *= SCALE_RETRANS; /* xxx/bg overflow! */
|
|
|
|
t = lookup(mac);
|
|
if (t->mac != mac) {
|
|
t->mac = mac;
|
|
t->nretrans = nretrans;
|
|
} else {
|
|
if ((t->nretrans + nretrans)/2 > MAX_SCALE_RETRANS)
|
|
t->nretrans = MAX_SCALE_RETRANS;
|
|
else
|
|
t->nretrans = (t->nretrans + nretrans)/2;
|
|
}
|
|
t->expire = MAX_EXPIRE;
|
|
//printf("+ %04x %d/4 %d\n", t->mac, t->nretrans, t->expire);
|
|
return;
|
|
}
|
|
|
|
void
|
|
cc2420_recv_ok(uip_ipaddr_t *from)
|
|
{
|
|
neigbour_update((*from)[1], 0);
|
|
}
|
|
|
|
/*
|
|
* +1: remote
|
|
* 0: local
|
|
* -1: unknown
|
|
*/
|
|
int
|
|
cc2420_check_remote(u16_t mac)
|
|
{
|
|
struct cc2420_neigbour *t;
|
|
|
|
/*
|
|
* Age neigbour table every 5*SCALE_DIV_EXPIRE=20 seconds.
|
|
*/
|
|
static clock_time_t toff;
|
|
unsigned now = ((clock_time() - toff)/CLOCK_SECOND)/SCALE_DIV_EXPIRE;
|
|
if (now >= AGE_INTERVAL) {
|
|
unsigned i;
|
|
|
|
//printf("aging\n");
|
|
for (i = 0; i < NNEIGBOURS; i++)
|
|
if (neigbours[i].expire >= now)
|
|
neigbours[i].expire -= now;
|
|
else
|
|
neigbours[i].mac = 0xffff; /* expired! */
|
|
toff = clock_time();
|
|
}
|
|
|
|
t = lookup(mac);
|
|
//printf(" %04x %d/4 %d\n", t->mac, t->nretrans, t->expire);
|
|
if (t->mac != mac)
|
|
return -1; /* unknown */
|
|
else if (t->nretrans >= SCALE_RETRANS_THRESHOLD)
|
|
return +1; /* remote */
|
|
else
|
|
return 0; /* local */
|
|
}
|