// uint16_t onewire_crc16(const uint8_t* input, uint16_t len, uint16_t crc);
// Lua: r = ow.crc16( buf, crc )
static int ow_crc16( lua_State *L )
{
size_t datalen;
const uint8_t *pdata = luaL_checklstring( L, 1, &datalen );
if(datalen > 65535)
return luaL_error( L, "wrong arg range" );
int crc = 0;
if(lua_isnumber(L, 2))
crc = lua_tointeger(L, 2);
if(crc > 65535)
return luaL_error( L, "wrong arg range" );
lua_pushinteger( L, onewire_crc16(pdata, (uint16_t)datalen, (uint16_t)crc) );
return 1;
}
void
owctr_update_counter(void *arg, int bank)
{
struct owctr_softc *sc = arg;
u_int32_t counter;
u_int16_t crc;
u_int8_t *buf;
rw_enter_write(&sc->sc_lock);
onewire_lock(sc->sc_onewire, 0);
if (onewire_reset(sc->sc_onewire) != 0)
goto done;
buf = malloc(DS2423_COUNTER_BUFSZ, M_DEVBUF, M_NOWAIT);
if (buf == NULL) {
printf("%s: malloc() failed\n", sc->sc_dev.dv_xname);
goto done;
}
onewire_matchrom(sc->sc_onewire, sc->sc_rom);
buf[0] = DSCTR_CMD_READ_MEMCOUNTER;
buf[1] = bank;
buf[2] = bank >> 8;
onewire_write_byte(sc->sc_onewire, buf[0]);
onewire_write_byte(sc->sc_onewire, buf[1]);
onewire_write_byte(sc->sc_onewire, buf[2]);
onewire_read_block(sc->sc_onewire, &buf[3], DS2423_COUNTER_BUFSZ-3);
crc = onewire_crc16(buf, DS2423_COUNTER_BUFSZ-2);
crc ^= buf[DS2423_COUNTER_BUF_CRC]
| (buf[DS2423_COUNTER_BUF_CRC+1] << 8);
if ( crc != 0xffff) {
printf("%s: invalid CRC\n", sc->sc_dev.dv_xname);
if (bank == DS2423_COUNTER_BANK_A) {
sc->sc_counterA.value = 0;
sc->sc_counterA.status = SENSOR_S_UNKNOWN;
sc->sc_counterA.flags |= SENSOR_FUNKNOWN;
} else {
sc->sc_counterB.value = 0;
sc->sc_counterB.status = SENSOR_S_UNKNOWN;
sc->sc_counterB.flags |= SENSOR_FUNKNOWN;
}
} else {
counter = buf[DS2423_COUNTER_BUF_COUNTER]
| (buf[DS2423_COUNTER_BUF_COUNTER+1] << 8)
| (buf[DS2423_COUNTER_BUF_COUNTER+2] << 16)
| (buf[DS2423_COUNTER_BUF_COUNTER+3] << 24);
if (bank == DS2423_COUNTER_BANK_A) {
sc->sc_counterA.value = counter;
sc->sc_counterA.status = SENSOR_S_UNSPEC;
sc->sc_counterA.flags &= ~SENSOR_FUNKNOWN;
} else {
sc->sc_counterB.value = counter;
sc->sc_counterB.status = SENSOR_S_UNSPEC;
sc->sc_counterB.flags &= ~SENSOR_FUNKNOWN;
}
}
onewire_reset(sc->sc_onewire);
free(buf, M_DEVBUF);
done:
onewire_unlock(sc->sc_onewire);
rw_exit_write(&sc->sc_lock);
}
