PERFORCE change 110355 for review
Warner Losh
imp at FreeBSD.org
Wed Nov 22 02:12:31 UTC 2006
http://perforce.freebsd.org/chv.cgi?CH=110355
Change 110355 by imp at imp_lighthouse on 2006/11/22 02:12:22
Remove useless junk that doesn't work.
calculate clock divisors correctly.
remove debugging
busy wait faster.
Affected files ...
.. //depot/projects/arm/src/sys/arm/at91/at91_twi.c#28 edit
Differences ...
==== //depot/projects/arm/src/sys/arm/at91/at91_twi.c#28 (text+ko) ====
@@ -227,133 +227,15 @@
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 @@
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;
}
@@ -435,8 +316,6 @@
* See http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2004-September/024411.html
* for details.
*/
- printf("%d: flags %#x len %d buf %p\n", i, msgs[i].flags,
- msgs[i].len, msgs[i].buf);
rdwr = (msgs[i].flags & IIC_M_RD) ? TWI_MMR_MREAD : 0;
WR4(sc, TWI_MMR, TWI_MMR_DADR(msgs[i].slave) | rdwr);
len = msgs[i].len;
@@ -448,10 +327,8 @@
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 {
@@ -459,16 +336,12 @@
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);
}
@@ -481,11 +354,6 @@
/* 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 }
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