void
at91spi_done(struct at91spi_softc *sc, int err)
{
struct spi_transfer *st;
/* called from interrupt handler */
if ((st = sc->sc_transfer) != NULL) {
sc->sc_transfer = NULL;
DPRINTFN(2, ("%s: st %p finished with error code %d\n", __FUNCTION__, st, err));
spi_done(st, err);
}
/* make sure we clear these bits out */
sc->sc_wchunk = sc->sc_rchunk = NULL;
at91spi_sched(sc);
}
/* Generic function to send and receive a byte */
uint8_t spi_rw_byte(uint8_t data_out) {
uint8_t data_in ;
spi_set_sck(8) ;
spi_data_len(8) ;
SPI->TX_DATAbits.DATA = data_out ;
spi_start() ;
while(!spi_done()) { /* Wait */ }
data_in = SPI->RX_DATAbits.DATA ;
spi_int_clear() ;
return data_in ;
}
void
at91spi_sched(struct at91spi_softc *sc)
{
struct spi_transfer *st;
int err;
while ((st = spi_transq_first(&sc->sc_q)) != NULL) {
DPRINTFN(2, ("%s: st=%p\n", __FUNCTION__, st));
/* remove the item */
spi_transq_dequeue(&sc->sc_q);
/* note that we are working on it */
sc->sc_transfer = st;
if ((err = at91spi_select(sc, st->st_slave)) != 0) {
spi_done(st, err);
continue;
}
/* setup chunks */
sc->sc_rchunk = sc->sc_wchunk = st->st_chunks;
/* now kick the master start to get the chip running */
at91spi_xfer(sc, TRUE);
/* enable error interrupts too: */
PUTREG(sc, SPI_IER, SPI_SR_MODF | SPI_SR_OVRES);
sc->sc_running = TRUE;
return;
}
DPRINTFN(2, ("%s: nothing to do anymore\n", __FUNCTION__));
PUTREG(sc, SPI_IDR, -1); /* disable interrupts */
at91spi_select(sc, -1);
sc->sc_running = FALSE;
}
