int
pcf_read(device_t dev, char *buf, int len, int *read, int last,
int delay /* us */)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int bytes, error = 0;
#ifdef PCFDEBUG
char *obuf = buf;
device_printf(dev, " << reading %d bytes\n", len);
#endif
PCF_LOCK(sc);
/* trig the bus to get the first data byte in S0 */
if (len) {
if (len == 1 && last)
/* just one byte to read */
pcf_set_S1(sc, ESO); /* no ack */
dummy_read(sc);
}
bytes = 0;
while (len) {
/* XXX delay needed here */
/* wait for trigged byte */
if ((error = pcf_wait_byte(sc))) {
pcf_stop_locked(sc);
goto error;
}
if (len == 1 && last)
/* ok, last data byte already in S0, no I2C activity
* on next pcf_get_S0() */
pcf_stop_locked(sc);
else if (len == 2 && last)
/* next trigged byte with no ack */
pcf_set_S1(sc, ESO);
/* receive byte, trig next byte */
*buf++ = pcf_get_S0(sc);
len --;
bytes ++;
};
error:
*read = bytes;
PCF_UNLOCK(sc);
#ifdef PCFDEBUG
device_printf(dev, " << %d bytes read (%d): %#x%s\n", bytes, error,
(unsigned)obuf[0], bytes > 1? "...": "");
#endif
return (error);
}
static int
pcf_start(device_t pcfdev, u_char slave, int timeout)
{
struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
int error = 0;
if ((PCF_GET_S1(pcf) & nBB) == 0)
return (IIC_EBUSBSY);
/* set slave address to PCF. Last bit (LSB) must be set correctly
* according to transfer direction */
PCF_SET_S0(pcf, slave);
/* START only */
PCF_SET_S1(pcf, PIN|ES0|STA|ACK);
pcf->pcf_started = 1;
/* wait for address sent, polling */
if ((error = pcf_wait_byte(pcf)))
goto error;
/* check for ACK */
if (pcf_noack(pcf, timeout)) {
error = IIC_ENOACK;
goto error;
}
return (0);
error:
pcf_stop(pcfdev);
return (error);
}
static int
pcf_repeated_start(device_t pcfdev, u_char slave, int timeout)
{
struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
int error = 0;
/* repeated start */
PCF_SET_S1(pcf, ES0|STA|STO|ACK);
/* set slave address to PCF. Last bit (LSB) must be set correctly
* according to transfer direction */
PCF_SET_S0(pcf, slave);
/* wait for address sent, polling */
if ((error = pcf_wait_byte(pcf)))
goto error;
/* check for ack */
if (pcf_noack(pcf, timeout)) {
error = IIC_ENOACK;
goto error;
}
return (0);
error:
pcf_stop(pcfdev);
return (error);
}
static int
pcf_read(device_t pcfdev, char *buf, int len, int *read, int last,
int delay /* us */)
{
struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
int bytes, error = 0;
#ifdef PCFDEBUG
kprintf("pcf%d: << reading %d bytes\n", device_get_unit(pcfdev), len);
#endif
/* trig the bus to get the first data byte in S0 */
if (len) {
if (len == 1 && last)
/* just one byte to read */
PCF_SET_S1(pcf, ES0); /* no ack */
dummy_read(pcf);
}
bytes = 0;
while (len) {
/* XXX delay needed here */
/* wait for trigged byte */
if ((error = pcf_wait_byte(pcf))) {
pcf_stop(pcfdev);
goto error;
}
if (len == 1 && last)
/* ok, last data byte already in S0, no I2C activity
* on next PCF_GET_S0() */
pcf_stop(pcfdev);
else if (len == 2 && last)
/* next trigged byte with no ack */
PCF_SET_S1(pcf, ES0);
/* receive byte, trig next byte */
*buf++ = PCF_GET_S0(pcf);
len --;
bytes ++;
}
error:
*read = bytes;
#ifdef PCFDEBUG
kprintf("pcf%d: << %d bytes read (%d)\n",
device_get_unit(pcfdev), bytes, error);
#endif
return (error);
}
int
pcf_start(device_t dev, u_char slave, int timeout)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int error = 0;
PCF_LOCK(sc);
#ifdef PCFDEBUG
device_printf(dev, " >> start for slave %#x\n", (unsigned)slave);
#endif
if ((pcf_get_S1(sc) & nBB) == 0) {
#ifdef PCFDEBUG
printf("pcf: busy!\n");
#endif
PCF_UNLOCK(sc);
return (IIC_EBUSBSY);
}
/* set slave address to PCF. Last bit (LSB) must be set correctly
* according to transfer direction */
pcf_set_S0(sc, slave);
/* START only */
pcf_set_S1(sc, PIN|ESO|STA|ACK);
sc->pcf_started = 1;
/* wait for address sent, polling */
if ((error = pcf_wait_byte(sc)))
goto error;
/* check for ACK */
if (pcf_noack(sc, timeout)) {
error = IIC_ENOACK;
#ifdef PCFDEBUG
printf("pcf: no ack on start!\n");
#endif
goto error;
}
PCF_UNLOCK(sc);
return (0);
error:
pcf_stop_locked(sc);
PCF_UNLOCK(sc);
return (error);
}
int
pcf_write(device_t dev, const char *buf, int len, int *sent, int timeout /* us */)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int bytes, error = 0;
#ifdef PCFDEBUG
device_printf(dev, " >> writing %d bytes: %#x%s\n", len,
(unsigned)buf[0], len > 1? "...": "");
#endif
bytes = 0;
PCF_LOCK(sc);
while (len) {
pcf_set_S0(sc, *buf++);
/* wait for the byte to be send */
if ((error = pcf_wait_byte(sc)))
goto error;
/* check if ack received */
if (pcf_noack(sc, timeout)) {
error = IIC_ENOACK;
goto error;
}
len --;
bytes ++;
}
error:
*sent = bytes;
PCF_UNLOCK(sc);
#ifdef PCFDEBUG
device_printf(dev, " >> %d bytes written (%d)\n", bytes, error);
#endif
return (error);
}
static int
pcf_write(device_t pcfdev, const char *buf, int len, int *sent,
int timeout /* us */)
{
struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
int bytes, error = 0;
#ifdef PCFDEBUG
kprintf("pcf%d: >> writing %d bytes\n", device_get_unit(pcfdev), len);
#endif
bytes = 0;
while (len) {
PCF_SET_S0(pcf, *buf++);
/* wait for the byte to be send */
if ((error = pcf_wait_byte(pcf)))
goto error;
/* check if ack received */
if (pcf_noack(pcf, timeout)) {
error = IIC_ENOACK;
goto error;
}
len --;
bytes ++;
}
error:
*sent = bytes;
#ifdef PCFDEBUG
kprintf("pcf%d: >> %d bytes written (%d)\n",
device_get_unit(pcfdev), bytes, error);
#endif
return (error);
}
int
pcf_repeated_start(device_t dev, u_char slave, int timeout)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int error = 0;
PCF_LOCK(sc);
#ifdef PCFDEBUG
device_printf(dev, " >> repeated start for slave %#x\n",
(unsigned)slave);
#endif
/* repeated start */
pcf_set_S1(sc, ESO|STA|STO|ACK);
/* set slave address to PCF. Last bit (LSB) must be set correctly
* according to transfer direction */
pcf_set_S0(sc, slave);
/* wait for address sent, polling */
if ((error = pcf_wait_byte(sc)))
goto error;
/* check for ack */
if (pcf_noack(sc, timeout)) {
error = IIC_ENOACK;
#ifdef PCFDEBUG
printf("pcf: no ack on repeated_start!\n");
#endif
goto error;
}
PCF_UNLOCK(sc);
return (0);
error:
pcf_stop_locked(sc);
PCF_UNLOCK(sc);
return (error);
}
