contiki-maca.c

/*
 * Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
 * to the MC1322x project (http://mc1322x.devl.org) and Contiki.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This file is part of the Contiki OS.
 *
 *
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>

/* contiki */
#include "radio.h"
#include "sys/process.h"
#include "net/packetbuf.h"
#include "net/netstack.h"

#include "mc1322x.h"
#include "contiki-conf.h"

#define CONTIKI_MACA_DEBUG 0
#if CONTIKI_MACA_DEBUG
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif

#ifndef CONTIKI_MACA_PREPEND_BYTE
#define CONTIKI_MACA_PREPEND_BYTE 0xff
#endif

#ifndef BLOCKING_TX
#define BLOCKING_TX 1
#endif

static volatile uint8_t tx_complete;
static volatile uint8_t tx_status;

/* contiki mac driver */

int contiki_maca_init(void);
int contiki_maca_on_request(void);
int contiki_maca_off_request(void);
int contiki_maca_read(void *buf, unsigned short bufsize);
int contiki_maca_prepare(const void *payload, unsigned short payload_len);
int contiki_maca_transmit(unsigned short transmit_len);
int contiki_maca_send(const void *payload, unsigned short payload_len);
int contiki_maca_channel_clear(void);
int contiki_maca_receiving_packet(void);
int contiki_maca_pending_packet(void);

const struct radio_driver contiki_maca_driver =
{
        .init = contiki_maca_init,
        .prepare = contiki_maca_prepare,
        .transmit = contiki_maca_transmit,
        .send = contiki_maca_send,
        .read = contiki_maca_read,
        .receiving_packet = contiki_maca_receiving_packet,
        .pending_packet = contiki_maca_pending_packet,
        .channel_clear = contiki_maca_channel_clear,
        .on = contiki_maca_on_request,
        .off = contiki_maca_off_request,
};

static volatile uint8_t contiki_maca_request_on = 0;
static volatile uint8_t contiki_maca_request_off = 0;

static process_event_t event_data_ready;

static volatile packet_t prepped_p;

int contiki_maca_init(void) {
//      trim_xtal();
//      vreg_init();
//      contiki_maca_init();
//      set_channel(0); /* channel 11 */
//      set_power(0x12); /* 0x12 is the highest, not documented */
        return 1;
}

/* CCA not implemented */
int contiki_maca_channel_clear(void) {
        return 1;
}

/* not sure how to check if a reception is in progress */
int contiki_maca_receiving_packet(void) {
        return 0;
}

int contiki_maca_pending_packet(void) {
        if (rx_head != NULL) {
                return 1;
        } else {
                return 0;
        }
}

int contiki_maca_on_request(void) {
        contiki_maca_request_on = 1;
        contiki_maca_request_off = 0;
        return 1;
}

int contiki_maca_off_request(void) {
        contiki_maca_request_on = 0;
        contiki_maca_request_off = 1;
        return 1;
}

/* it appears that the mc1332x radio cannot */
/* receive packets where the last three bits of the first byte */
/* is equal to 2 --- even in promiscuous mode */
int contiki_maca_read(void *buf, unsigned short bufsize) {
        volatile uint32_t i;
        volatile packet_t *p;
        
        if((p = rx_packet())) {
                PRINTF("maca read");
#if CONTIKI_MACA_RAW_MODE
                /* offset + 1 and size - 1 to strip the raw mode prepended byte */
                /* work around since maca can't receive acks bigger than five bytes */
                PRINTF(" raw mode");
                p->length -= 1;
                p->offset += 1;
#endif
                PRINTF(": p->length 0x%0x bufsize 0x%0x \n\r", p->length, bufsize);
                if((p->length) < bufsize) bufsize = (p->length);
                memcpy(buf, (uint8_t *)(p->data + p->offset), bufsize);
                packetbuf_set_attr(PACKETBUF_ATTR_LINK_QUALITY,p->lqi);
                packetbuf_set_attr(PACKETBUF_ATTR_TIMESTAMP,p->rx_time);
#if CONTIKI_MACA_DEBUG
                for( i = p->offset ; i < (bufsize + p->offset) ; i++) {
                        PRINTF(" %02x",p->data[i]);
                }
#endif 
                PRINTF("\n\r");
                free_packet(p);
                return bufsize;
        } else {
                return 0;
        }
}

/* copies a payload into the prepped packet */
/* transmit sends the prepped packet everytime it is called */
/* Contiki may call prepare once and then transmit several times to send */
/* the same packet repeatedly */
int contiki_maca_prepare(const void *payload, unsigned short payload_len) {
        volatile int i;
                
        PRINTF("contiki maca prepare");
#if CONTIKI_MACA_RAW_MODE
        prepped_p.offset = 1;
        prepped_p.length = payload_len + 1;
#else 
        prepped_p.offset = 0;
        prepped_p.length = payload_len;
#endif
        if(payload_len > MAX_PACKET_SIZE)  return RADIO_TX_ERR;
        memcpy((uint8_t *)(prepped_p.data + prepped_p.offset), payload, payload_len);
#if CONTIKI_MACA_RAW_MODE
        prepped_p.offset = 0;
        prepped_p.data[0] = CONTIKI_MACA_PREPEND_BYTE;
        PRINTF(" raw mode");
#endif
#if CONTIKI_MACA_DEBUG
        PRINTF(": sending %d bytes\n\r", payload_len);
        for(i = prepped_p.offset ; i < (prepped_p.length + prepped_p.offset); i++) {
                PRINTF(" %02x",prepped_p.data[i]);
        }
        PRINTF("\n\r");
#endif
        
        return RADIO_TX_OK;

}

/* gets a packet from the radio (if available), */
/* copies the prepared packet prepped_p */
/* and transmits it */
int contiki_maca_transmit(unsigned short transmit_len) {
        volatile packet_t *p;

        PRINTF("contiki maca transmit\n\r");
#if BLOCKING_TX
        tx_complete = 0;
#endif
        if(p = get_free_packet()) {
                p->offset = prepped_p.offset; 
                p->length = prepped_p.length; 
                memcpy((uint8_t *)(p->data + p->offset), 
                       (const uint8_t *)(prepped_p.data + prepped_p.offset), 
                       prepped_p.length);
                tx_packet(p);
        } else {
                PRINTF("couldn't get free packet for transmit\n\r");
                return RADIO_TX_ERR;
        }

#if BLOCKING_TX
        /* block until tx_complete, set by contiki_maca_tx_callback */
        while(!tx_complete && (tx_head != 0));
#endif  
}

int contiki_maca_send(const void *payload, unsigned short payload_len) {
        contiki_maca_prepare(payload, payload_len);
        contiki_maca_transmit(payload_len);
        switch(tx_status) {
        case SUCCESS:
        case CRC_FAILED: /* CRC_FAILED is usually an ack */
                PRINTF("TXOK\n\r");
                return RADIO_TX_OK;
        case NO_ACK:
                PRINTF("NOACK\n\r");
                return RADIO_TX_NOACK;
        default:
                PRINTF("TXERR\n\r");
                return RADIO_TX_ERR;
        }
}

PROCESS(contiki_maca_process, "maca process");
PROCESS_THREAD(contiki_maca_process, ev, data)
{
        volatile uint32_t i;
        int len;
        
        PROCESS_BEGIN();

        while (1) {
                PROCESS_YIELD();

                /* check if there is a request to turn the radio on or off */
                if(contiki_maca_request_on == 1) {
                        contiki_maca_request_on = 0;
//                      maca_on();
                }

                if(contiki_maca_request_off == 1) {
                        contiki_maca_request_off = 0;
//                      maca_off();
                }

                if (rx_head != NULL) {
                        packetbuf_clear();
                        len = contiki_maca_read(packetbuf_dataptr(), PACKETBUF_SIZE);
                        if(len > 0) {
                                packetbuf_set_datalen(len);                             
                                NETSTACK_RDC.input();
                        }
                }
                /* Call ourself again to handle remaining packets in the queue */
                if (rx_head != NULL) {
                        process_poll(&contiki_maca_process);
                }
                
        };
        
        PROCESS_END();
}

void maca_rx_callback(volatile packet_t *p __attribute((unused))) {
        process_poll(&contiki_maca_process);
}


#if BLOCKING_TX
void maca_tx_callback(volatile packet_t *p __attribute((unused))) {
        tx_complete = 1;
        tx_status = p->status;
}
#endif