MFp4: Make it work :-)
o Don't delay when checking the done bits. There's no gain other than a small performance hit. o calculate the clock divisors better (things are still way slow, so maybe there's more here?) o don't always fail reset. Always succeed instead. o fix inverted logic around at91_twi_wait() return value o remove debug code o remove unneeded, unworking junk
This commit is contained in:
imp
parent
a272d3414e
commit
ceddc20728
@ -227,133 +227,15 @@ static int
|
||||
at91_twi_wait(struct at91_twi_softc *sc, uint32_t bit)
|
||||
{
|
||||
int err = 0;
|
||||
int counter = 10000;
|
||||
int counter = 100000;
|
||||
|
||||
while (!(RD4(sc, TWI_SR) & bit) && counter-- >= 0)
|
||||
DELAY(10);
|
||||
continue;
|
||||
if (counter <= 0)
|
||||
err = EIO;
|
||||
return (err);
|
||||
}
|
||||
|
||||
/*
|
||||
* Stop the transfer by entering a STOP state on the iic bus. For read
|
||||
* operations, we've already entered the STOP state, since we need to do
|
||||
* that to read the last character. For write operations, we need to
|
||||
* wait for the TXCOMP bit to turn on before returning.
|
||||
*/
|
||||
static int
|
||||
at91_twi_stop(device_t dev)
|
||||
{
|
||||
struct at91_twi_softc *sc;
|
||||
int err = 0;
|
||||
|
||||
sc = device_get_softc(dev);
|
||||
if (sc->sc_started) {
|
||||
WR4(sc, TWI_CR, TWI_CR_STOP);
|
||||
err = at91_twi_wait(sc, TWI_SR_TXCOMP);
|
||||
}
|
||||
return (err);
|
||||
}
|
||||
|
||||
/*
|
||||
* enter a START condition without requiring the device to be in a STOP
|
||||
* state.
|
||||
*/
|
||||
static int
|
||||
at91_twi_repeated_start(device_t dev, u_char slave, int timeout)
|
||||
{
|
||||
struct at91_twi_softc *sc;
|
||||
|
||||
sc = device_get_softc(dev);
|
||||
WR4(sc, TWI_MMR, TWI_MMR_DADR(slave));
|
||||
return (0);
|
||||
}
|
||||
|
||||
/*
|
||||
* enter a START condition from an idle state.
|
||||
*/
|
||||
static int
|
||||
at91_twi_start(device_t dev, u_char slave, int timeout)
|
||||
{
|
||||
struct at91_twi_softc *sc;
|
||||
|
||||
sc = device_get_softc(dev);
|
||||
WR4(sc, TWI_MMR, TWI_MMR_DADR(slave));
|
||||
sc->sc_started = 1;
|
||||
return (0);
|
||||
}
|
||||
|
||||
static int
|
||||
at91_twi_write(device_t dev, char *buf, int len, int *sent, int timeout /* us */)
|
||||
{
|
||||
struct at91_twi_softc *sc;
|
||||
uint8_t *walker;
|
||||
int err = 0;
|
||||
|
||||
walker = buf;
|
||||
sc = device_get_softc(dev);
|
||||
AT91_TWI_LOCK(sc);
|
||||
WR4(sc, TWI_MMR, ~TWI_MMR_MREAD & RD4(sc, TWI_MMR));
|
||||
WR4(sc, TWI_CR, TWI_CR_START);
|
||||
sc->sc_started = 1;
|
||||
// WR4(sc, TWI_IER, TWI_SR_TXRDY);
|
||||
while (len--) {
|
||||
WR4(sc, TWI_THR, *walker++);
|
||||
while (!(sc->flags & TXRDY)) {
|
||||
err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH, "twiwr",
|
||||
0);
|
||||
if (err)
|
||||
goto errout;
|
||||
}
|
||||
}
|
||||
errout:;
|
||||
WR4(sc, TWI_IDR, TWI_SR_TXRDY);
|
||||
AT91_TWI_UNLOCK(sc);
|
||||
return (err);
|
||||
}
|
||||
|
||||
static int
|
||||
at91_twi_read(device_t dev, char *buf, int len, int *read, int last,
|
||||
int delay /* us */)
|
||||
{
|
||||
struct at91_twi_softc *sc;
|
||||
char *walker;
|
||||
int err = 0;
|
||||
|
||||
walker = buf;
|
||||
sc = device_get_softc(dev);
|
||||
AT91_TWI_LOCK(sc);
|
||||
WR4(sc, TWI_MMR, TWI_MMR_MREAD | RD4(sc, TWI_MMR));
|
||||
WR4(sc, TWI_CR, TWI_CR_START);
|
||||
sc->sc_started = 1;
|
||||
// WR4(sc, TWI_IER, TWI_SR_RXRDY);
|
||||
while (len-- > 0) {
|
||||
err = 0;
|
||||
while (!(sc->flags & RXRDY)) {
|
||||
err = msleep(sc, &sc->sc_mtx, PZERO | PCATCH, "twird",
|
||||
0);
|
||||
if (err)
|
||||
goto errout;
|
||||
}
|
||||
sc->flags &= ~RXRDY;
|
||||
*walker++ = RD4(sc, TWI_RHR) & 0xff;
|
||||
if (len == 1 && last)
|
||||
break;
|
||||
}
|
||||
if (!last)
|
||||
goto errout;
|
||||
WR4(sc, TWI_CR, TWI_CR_STOP);
|
||||
err = at91_twi_wait(sc, TWI_SR_TXCOMP);
|
||||
*walker = RD4(sc, TWI_RHR) & 0xff;
|
||||
if (read)
|
||||
*read = walker - buf;
|
||||
errout:;
|
||||
WR4(sc, TWI_IDR, TWI_SR_RXRDY);
|
||||
AT91_TWI_UNLOCK(sc);
|
||||
return (err);
|
||||
}
|
||||
|
||||
static int
|
||||
at91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
|
||||
{
|
||||
@ -371,22 +253,21 @@ at91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
|
||||
rate = 1;
|
||||
|
||||
/*
|
||||
* 8 * is because "rate == 1" -> 4 clocks down, 4 clocks up. The
|
||||
* speeds are for 1.5kb/s, 45kb/s and 90kb/s.
|
||||
*/
|
||||
switch (speed) {
|
||||
case IIC_SLOW:
|
||||
ckdiv = 8 * AT91C_MASTER_CLOCK / 1500;
|
||||
ckdiv = AT91C_MASTER_CLOCK / (1500 * 4) - 2;
|
||||
break;
|
||||
|
||||
case IIC_FAST:
|
||||
ckdiv = 8 * AT91C_MASTER_CLOCK / 45000;
|
||||
ckdiv = AT91C_MASTER_CLOCK / (45000 * 4) - 2;
|
||||
break;
|
||||
|
||||
case IIC_UNKNOWN:
|
||||
case IIC_FASTEST:
|
||||
default:
|
||||
ckdiv = 8 * AT91C_MASTER_CLOCK / 90000;
|
||||
ckdiv = AT91C_MASTER_CLOCK / (90000 * 4) - 2;
|
||||
break;
|
||||
}
|
||||
|
||||
@ -396,7 +277,7 @@ at91_twi_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
|
||||
WR4(sc, TWI_CR, TWI_CR_MSEN | TWI_CR_SVDIS);
|
||||
WR4(sc, TWI_CWGR, sc->cwgr);
|
||||
|
||||
return EIO;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
@ -446,10 +327,8 @@ at91_twi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
|
||||
while (len--) {
|
||||
if (len == 0)
|
||||
WR4(sc, TWI_CR, TWI_CR_STOP);
|
||||
if (!at91_twi_wait(sc, TWI_SR_RXRDY)) {
|
||||
printf("1\n");
|
||||
if (at91_twi_wait(sc, TWI_SR_RXRDY))
|
||||
return (EIO);
|
||||
}
|
||||
*buf++ = RD4(sc, TWI_RHR) & 0xff;
|
||||
}
|
||||
} else {
|
||||
@ -457,16 +336,12 @@ at91_twi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
|
||||
WR4(sc, TWI_THR, *buf++);
|
||||
if (len == 0)
|
||||
WR4(sc, TWI_CR, TWI_CR_STOP);
|
||||
if (!at91_twi_wait(sc, TWI_SR_TXRDY)) {
|
||||
printf("3\n");
|
||||
if (at91_twi_wait(sc, TWI_SR_TXRDY))
|
||||
return (EIO);
|
||||
}
|
||||
}
|
||||
}
|
||||
if (!at91_twi_wait(sc, TWI_SR_TXCOMP)) {
|
||||
printf("2\n");
|
||||
if (at91_twi_wait(sc, TWI_SR_TXCOMP))
|
||||
return (EIO);
|
||||
}
|
||||
}
|
||||
return (0);
|
||||
}
|
||||
@ -479,11 +354,6 @@ static device_method_t at91_twi_methods[] = {
|
||||
|
||||
/* iicbus interface */
|
||||
DEVMETHOD(iicbus_callback, at91_twi_callback),
|
||||
DEVMETHOD(iicbus_repeated_start, at91_twi_repeated_start),
|
||||
DEVMETHOD(iicbus_start, at91_twi_start),
|
||||
DEVMETHOD(iicbus_stop, at91_twi_stop),
|
||||
DEVMETHOD(iicbus_write, at91_twi_write),
|
||||
DEVMETHOD(iicbus_read, at91_twi_read),
|
||||
DEVMETHOD(iicbus_reset, at91_twi_rst_card),
|
||||
DEVMETHOD(iicbus_transfer, at91_twi_transfer),
|
||||
{ 0, 0 }
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user