/*ARGSUSED*/
int
i2c_bitbang_send_stop(void *v, int flags, i2c_bitbang_ops_t ops)
{
BB_DIR(OUTPUT);
BB_SET( SCL);
delay(4); /* stop setup time (4.0 uS) */
BB_SET(SDA | SCL);
return (0);
}
/*ARGSUSED*/
int
i2c_bitbang_send_start(void *v, int flags, i2c_bitbang_ops_t ops)
{
BB_DIR(OUTPUT);
BB_SET(SDA | SCL);
delay(5); /* bus free time (4.7 uS) */
BB_SET( SCL);
delay(4); /* start hold time (4.0 uS) */
BB_SET( 0);
delay(5); /* clock low time (4.7 uS) */
return (0);
}
int
i2c_bitbang_write_byte(void *v, uint8_t val, int flags,
i2c_bitbang_ops_t ops)
{
uint32_t bit;
uint8_t mask;
int error;
BB_DIR(OUTPUT);
for (mask = 0x80; mask != 0; mask >>= 1) {
bit = (val & mask) ? SDA : 0;
BB_SET(bit );
delay(1); /* data setup time (250 nS) */
BB_SET(bit | SCL);
delay(4); /* clock high time (4.0 uS) */
BB_SET(bit );
delay(5); /* clock low time (4.7 uS) */
}
BB_DIR(INPUT);
BB_SET(SDA );
delay(5);
BB_SET(SDA | SCL);
delay(4);
error = (BB_READ & SDA) ? EIO : 0;
BB_SET(SDA );
delay(5);
if (flags & I2C_F_STOP)
(void) i2c_bitbang_send_stop(v, flags, ops);
return (error);
}
/*---------------------------------------------------------------------------*/
const struct mac_driver *
xmac_init(const struct radio_driver *d)
{
#if WITH_TIMETABLE
timetable_clear(&xmac_timetable);
#endif
radio_is_on = 0;
waiting_for_packet = 0;
PT_INIT(&pt);
rtimer_set(&rt, RTIMER_NOW() + xmac_config.off_time, 1,
TC(powercycle), NULL);
xmac_is_on = 1;
radio = d;
radio->set_receive_function(input_packet);
BB_SET("xmac.state_addr", (int) &waiting_for_packet);
BB_SET(XMAC_RECEIVER, 0);
BB_SET(XMAC_STROBES, 0);
BB_SET(XMAC_SEND_WITH_ACK, 0);
BB_SET(XMAC_SEND_WITH_NOACK, 0);
return &xmac_driver;
}
int
i2c_bitbang_read_byte(void *v, uint8_t *valp, int flags,
i2c_bitbang_ops_t ops)
{
int i;
uint8_t val = 0;
uint32_t bit;
BB_DIR(INPUT);
BB_SET(SDA );
for (i = 0; i < 8; i++) {
val <<= 1;
BB_SET(SDA | SCL);
if (i2c_wait_for_scl(v, ops) != 0)
return (EIO);
delay(4); /* clock high time (4.0 uS) */
if (BB_READ & SDA)
val |= 1;
BB_SET(SDA );
delay(5); /* clock low time (4.7 uS) */
}
bit = (flags & I2C_F_LAST) ? SDA : 0;
BB_DIR(OUTPUT);
BB_SET(bit );
delay(1); /* data setup time (250 nS) */
BB_SET(bit | SCL);
if (i2c_wait_for_scl(v, ops) != 0)
return (EIO);
delay(4); /* clock high time (4.0 uS) */
BB_SET(bit );
delay(5); /* clock low time (4.7 uS) */
BB_DIR(INPUT);
BB_SET(SDA );
delay(5);
if ((flags & (I2C_F_STOP | I2C_F_LAST)) == (I2C_F_STOP | I2C_F_LAST))
(void) i2c_bitbang_send_stop(v, flags, ops);
*valp = val;
return (0);
}
/*---------------------------------------------------------------------------*/
static int
send_packet(void)
{
rtimer_clock_t t0;
rtimer_clock_t t;
int strobes;
struct xmac_hdr *hdr;
int got_ack = 0;
struct xmac_hdr msg;
int len;
int is_broadcast = 0;
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send");
#endif
#if WITH_CHANNEL_CHECK
/* Check if there are other strobes in the air. */
waiting_for_packet = 1;
on();
t0 = RTIMER_NOW();
while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + xmac_config.strobe_wait_time * 2)) {
len = radio->read(&msg, sizeof(msg));
if(len > 0) {
someone_is_sending = 1;
}
}
waiting_for_packet = 0;
while(someone_is_sending); /* {printf("z");}*/
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send 2");
#endif /* WITH_TIMETABLE */
#endif /* WITH_CHANNEL_CHECK */
/* By setting we_are_sending to one, we ensure that the rtimer
powercycle interrupt do not interfere with us sending the packet. */
we_are_sending = 1;
off();
rimebuf_hdralloc(sizeof(struct xmac_hdr));
hdr = rimebuf_hdrptr();
rimeaddr_copy(&hdr->sender, &rimeaddr_node_addr);
rimeaddr_copy(&hdr->receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER));
if(rimeaddr_cmp(&hdr->receiver, &rimeaddr_null)) {
is_broadcast = 1;
}
rimebuf_compact();
t0 = RTIMER_NOW();
strobes = 0;
BB_SET(XMAC_RECEIVER, hdr->receiver.u16[0]);
LEDS_ON(LEDS_BLUE);
/* Send a train of strobes until the receiver answers with an ACK. */
/* Turn on the radio to listen for the strobe ACK. */
if(!is_broadcast) {
on();
}
watchdog_stop();
got_ack = 0;
for(strobes = 0;
got_ack == 0 &&
RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + xmac_config.strobe_time);
strobes++) {
t = RTIMER_NOW();
rimeaddr_copy(&msg.sender, &rimeaddr_node_addr);
rimeaddr_copy(&msg.receiver, rimebuf_addr(RIMEBUF_ADDR_RECEIVER));
#if WITH_TIMETABLE
if(rimeaddr_cmp(&msg.receiver, &rimeaddr_null)) {
TIMETABLE_TIMESTAMP(xmac_timetable, "send broadcast strobe");
} else {
TIMETABLE_TIMESTAMP(xmac_timetable, "send strobe");
}
#endif
if(is_broadcast) {
/* If we are sending a broadcast, we don't send strobes, we
simply send the data packet repetedly */
radio->send(rimebuf_hdrptr(), rimebuf_totlen());
} else {
/* Send the strobe packet. */
radio->send((const uint8_t *)&msg, sizeof(struct xmac_hdr));
}
CPRINTF("+");
while(got_ack == 0 &&
RTIMER_CLOCK_LT(RTIMER_NOW(), t + xmac_config.strobe_wait_time)) {
/* See if we got an ACK */
len = radio->read((uint8_t *)&msg, sizeof(struct xmac_hdr));
if(len > 0) {
CPRINTF("_");
if(rimeaddr_cmp(&msg.sender, &rimeaddr_node_addr) &&
rimeaddr_cmp(&msg.receiver, &rimeaddr_node_addr)) {
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send ack received");
#endif
CPRINTF("@");
/* We got an ACK from the receiver, so we can immediately send
the packet. */
got_ack = 1;
}
}
}
/* XXX: turn off radio if we haven't heard an ACK within a
specified time interval. */
/* if(got_ack == 0) {
off();
while(RTIMER_CLOCK_LT(RTIMER_NOW(), t + xmac_config.strobe_wait_time));
on();
}*/
}
if(got_ack /* XXX && needs_ack */) {
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send got ack");
#endif
on(); /* Wait for possible ACK packet */
} else if(!is_broadcast) {
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send no ack received");
#endif
on(); /* shell ping don't seem to work with off() here, so we'll
keep it on() for a while. */
}
/* Send the data packet. */
if(is_broadcast || got_ack) {
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send packet");
#endif
radio->send(rimebuf_hdrptr(), rimebuf_totlen());
CPRINTF("#");
}
watchdog_start();
PRINTF("xmac: send (strobes=%u,len=%u,%s), done\n", strobes,
rimebuf_totlen(), got_ack ? "ack" : "no ack");
BB_SET(XMAC_STROBES, strobes);
if(got_ack) {
BB_INC(XMAC_SEND_WITH_ACK, 1);
} else {
BB_INC(XMAC_SEND_WITH_NOACK, 1);
}
/* printf("Strobe %d got_ack %d\n", strobes, got_ack);*/
we_are_sending = 0;
#if WITH_TIMETABLE
TIMETABLE_TIMESTAMP(xmac_timetable, "send we_are_sending = 0");
#endif
LEDS_OFF(LEDS_BLUE);
return 1;
}
