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twsi: Rework how we handle the i2c messages

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We use to handle each message separately in i2c_transfer but that cannot
work with message with NOSTOP as it confuses the controller that we disable
the interrupts and start a new message.
Handle every message in the interrupt handler and fire a new start condition
if the previous message have NOSTOP, the controller understand this as a
repeated start.
This fixes booting on Allwinner A10/A20 platform where before the i2c controller
used to write 0 to the PMIC register that control the regulators as it though that
this was the continuation of the write message.

Tested on:   A20 BananaPi, Cubieboard 1 (kevans)
Reported by:	kevans
MFC after:	1 month
This commit is contained in:
Emmanuel Vadot 2020-01-10 18:52:14 +00:00
parent 1171c633fb
commit b74b94d2a1
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=356609
2 changed files with 118 additions and 120 deletions
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234
sys/dev/iicbus/twsi/twsi.c
View File

@ -481,7 +481,6 @@ static int
twsi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
{
struct twsi_softc *sc;
int i;
sc = device_get_softc(dev);
@ -495,28 +494,25 @@ twsi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
debugf(dev, "transmitting %d messages\n", nmsgs);
debugf(sc->dev, "status=%x\n", TWSI_READ(sc, sc->reg_status));
for (i = 0; i < nmsgs && sc->error == 0; i++) {
sc->transfer = 1;
sc->msg = &msgs[i];
debugf(dev, "msg[%d] flags: %x\n", i, msgs[i].flags);
debugf(dev, "msg[%d] len: %d\n", i, msgs[i].len);
sc->nmsgs = nmsgs;
sc->msgs = msgs;
sc->msg_idx = 0;
sc->transfer = 1;
/* Send start and re-enable interrupts */
sc->control_val = TWSI_CONTROL_TWSIEN |
TWSI_CONTROL_INTEN | TWSI_CONTROL_ACK;
if (sc->msg->len == 1)
sc->control_val &= ~TWSI_CONTROL_ACK;
TWSI_WRITE(sc, sc->reg_control, sc->control_val | TWSI_CONTROL_START);
while (sc->error == 0 && sc->transfer != 0) {
pause_sbt("twsi", SBT_1MS * 30, SBT_1MS, 0);
}
/* Send start and re-enable interrupts */
sc->control_val = TWSI_CONTROL_TWSIEN |
TWSI_CONTROL_INTEN | TWSI_CONTROL_ACK;
if (sc->msgs[0].len == 1)
sc->control_val &= ~TWSI_CONTROL_ACK;
TWSI_WRITE(sc, sc->reg_control, sc->control_val | TWSI_CONTROL_START);
while (sc->error == 0 && sc->transfer != 0) {
pause_sbt("twsi", SBT_1MS * 30, SBT_1MS, 0);
}
debugf(sc->dev, "pause finish\n");
debugf(dev, "Done with msg[%d]\n", i);
if (sc->error) {
debugf(sc->dev, "Error, aborting (%d)\n", sc->error);
TWSI_WRITE(sc, sc->reg_control, 0);
goto out;
}
if (sc->error) {
debugf(sc->dev, "Error, aborting (%d)\n", sc->error);
TWSI_WRITE(sc, sc->reg_control, 0);
}
/* Disable module and interrupts */
@ -524,7 +520,6 @@ twsi_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
TWSI_WRITE(sc, sc->reg_control, 0);
debugf(sc->dev, "status=%x\n", TWSI_READ(sc, sc->reg_status));
out:
return (sc->error);
}
@ -537,122 +532,123 @@ twsi_intr(void *arg)
sc = arg;
debugf(sc->dev, "Got interrupt\n");
debugf(sc->dev, "Got interrupt Current msg=%x\n", sc->msg_idx);
while (TWSI_READ(sc, sc->reg_control) & TWSI_CONTROL_IFLG) {
status = TWSI_READ(sc, sc->reg_status);
debugf(sc->dev, "status=%x\n", status);
status = TWSI_READ(sc, sc->reg_status);
debugf(sc->dev, "initial status=%x\n", status);
switch (status) {
case TWSI_STATUS_START:
case TWSI_STATUS_RPTD_START:
/* Transmit the address */
debugf(sc->dev, "Send the address\n");
switch (status) {
case TWSI_STATUS_START:
case TWSI_STATUS_RPTD_START:
/* Transmit the address */
debugf(sc->dev, "Send the address\n");
if (sc->msg->flags & IIC_M_RD)
TWSI_WRITE(sc, sc->reg_data,
sc->msg->slave | LSB);
else
TWSI_WRITE(sc, sc->reg_data,
sc->msg->slave & ~LSB);
if (sc->msgs[sc->msg_idx].flags & IIC_M_RD)
TWSI_WRITE(sc, sc->reg_data,
sc->msgs[sc->msg_idx].slave | LSB);
else
TWSI_WRITE(sc, sc->reg_data,
sc->msgs[sc->msg_idx].slave & ~LSB);
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
case TWSI_STATUS_ADDR_W_ACK:
debugf(sc->dev, "Ack received after transmitting the address (write)\n");
/* Directly send the first byte */
sc->sent_bytes = 0;
debugf(sc->dev, "Sending byte 0 = %x\n", sc->msgs[sc->msg_idx].buf[0]);
TWSI_WRITE(sc, sc->reg_data, sc->msgs[sc->msg_idx].buf[0]);
case TWSI_STATUS_ADDR_W_ACK:
debugf(sc->dev, "Ack received after transmitting the address\n");
/* Directly send the first byte */
sc->sent_bytes = 0;
debugf(sc->dev, "Sending byte 0 = %x\n", sc->msg->buf[0]);
TWSI_WRITE(sc, sc->reg_data, sc->msg->buf[0]);
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
case TWSI_STATUS_ADDR_R_ACK:
debugf(sc->dev, "Ack received after transmitting the address (read)\n");
sc->recv_bytes = 0;
case TWSI_STATUS_ADDR_R_ACK:
debugf(sc->dev, "Ack received after transmitting the address\n");
sc->recv_bytes = 0;
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
case TWSI_STATUS_ADDR_W_NACK:
case TWSI_STATUS_ADDR_R_NACK:
debugf(sc->dev, "No ack received after transmitting the address\n");
sc->transfer = 0;
sc->error = ETIMEDOUT;
sc->control_val = 0;
wakeup(sc);
break;
case TWSI_STATUS_ADDR_W_NACK:
case TWSI_STATUS_ADDR_R_NACK:
debugf(sc->dev, "No ack received after transmitting the address\n");
sc->transfer = 0;
sc->error = ETIMEDOUT;
sc->control_val = 0;
wakeup(sc);
break;
case TWSI_STATUS_DATA_WR_ACK:
debugf(sc->dev, "Ack received after transmitting data\n");
if (sc->sent_bytes++ == (sc->msg->len - 1)) {
debugf(sc->dev, "Done sending all the bytes\n");
/* Send stop, no interrupts on stop */
if (!(sc->msg->flags & IIC_M_NOSTOP)) {
debugf(sc->dev, "Done TX data, send stop\n");
TWSI_WRITE(sc, sc->reg_control,
sc->control_val | TWSI_CONTROL_STOP);
} else {
sc->control_val &= ~TWSI_CONTROL_INTEN;
TWSI_WRITE(sc, sc->reg_control,
sc->control_val);
}
transfer_done = 1;
} else {
debugf(sc->dev, "Sending byte %d = %x\n",
sc->sent_bytes,
sc->msg->buf[sc->sent_bytes]);
TWSI_WRITE(sc, sc->reg_data,
sc->msg->buf[sc->sent_bytes]);
case TWSI_STATUS_DATA_WR_ACK:
debugf(sc->dev, "Ack received after transmitting data\n");
if (sc->sent_bytes++ == (sc->msgs[sc->msg_idx].len - 1)) {
debugf(sc->dev, "Done sending all the bytes for msg %d\n", sc->msg_idx);
/* Send stop, no interrupts on stop */
if (!(sc->msgs[sc->msg_idx].flags & IIC_M_NOSTOP)) {
debugf(sc->dev, "Done TX data, send stop\n");
TWSI_WRITE(sc, sc->reg_control,
sc->control_val);
}
break;
case TWSI_STATUS_DATA_RD_ACK:
debugf(sc->dev, "Ack received after receiving data\n");
debugf(sc->dev, "msg_len=%d recv_bytes=%d\n", sc->msg->len, sc->recv_bytes);
sc->msg->buf[sc->recv_bytes++] = TWSI_READ(sc, sc->reg_data);
/* If we only have one byte left, disable ACK */
if (sc->msg->len - sc->recv_bytes == 1)
sc->control_val &= ~TWSI_CONTROL_ACK;
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
case TWSI_STATUS_DATA_RD_NOACK:
if (sc->msg->len - sc->recv_bytes == 1) {
sc->msg->buf[sc->recv_bytes++] = TWSI_READ(sc, sc->reg_data);
debugf(sc->dev, "Done RX data, send stop (2)\n");
if (!(sc->msg->flags & IIC_M_NOSTOP))
TWSI_WRITE(sc, sc->reg_control,
sc->control_val | TWSI_CONTROL_STOP);
sc->control_val | TWSI_CONTROL_STOP);
} else {
debugf(sc->dev, "No ack when receiving data\n");
sc->error = ENXIO;
sc->control_val = 0;
debugf(sc->dev, "Done TX data with NO_STOP\n");
TWSI_WRITE(sc, sc->reg_control, sc->control_val | TWSI_CONTROL_START);
}
sc->transfer = 0;
transfer_done = 1;
break;
sc->msg_idx++;
if (sc->msg_idx == sc->nmsgs) {
debugf(sc->dev, "transfer_done=1\n");
transfer_done = 1;
}
} else {
debugf(sc->dev, "Sending byte %d = %x\n",
sc->sent_bytes,
sc->msgs[sc->msg_idx].buf[sc->sent_bytes]);
TWSI_WRITE(sc, sc->reg_data,
sc->msgs[sc->msg_idx].buf[sc->sent_bytes]);
TWSI_WRITE(sc, sc->reg_control,
sc->control_val);
}
break;
default:
debugf(sc->dev, "status=%x hot handled\n", status);
sc->transfer = 0;
case TWSI_STATUS_DATA_RD_ACK:
debugf(sc->dev, "Ack received after receiving data\n");
debugf(sc->dev, "msg_len=%d recv_bytes=%d\n", sc->msgs[sc->msg_idx].len, sc->recv_bytes);
sc->msgs[sc->msg_idx].buf[sc->recv_bytes++] = TWSI_READ(sc, sc->reg_data);
/* If we only have one byte left, disable ACK */
if (sc->msgs[sc->msg_idx].len - sc->recv_bytes == 1)
sc->control_val &= ~TWSI_CONTROL_ACK;
if (sc->msgs[sc->msg_idx].len - sc->recv_bytes) {
sc->msg_idx++;
if (sc->msg_idx == sc->nmsgs - 1)
transfer_done = 1;
}
TWSI_WRITE(sc, sc->reg_control, sc->control_val);
break;
case TWSI_STATUS_DATA_RD_NOACK:
if (sc->msgs[sc->msg_idx].len - sc->recv_bytes == 1) {
sc->msgs[sc->msg_idx].buf[sc->recv_bytes++] = TWSI_READ(sc, sc->reg_data);
debugf(sc->dev, "Done RX data, send stop (2)\n");
if (!(sc->msgs[sc->msg_idx].flags & IIC_M_NOSTOP))
TWSI_WRITE(sc, sc->reg_control,
sc->control_val | TWSI_CONTROL_STOP);
} else {
debugf(sc->dev, "No ack when receiving data\n");
sc->error = ENXIO;
sc->control_val = 0;
wakeup(sc);
break;
}
sc->transfer = 0;
transfer_done = 1;
break;
if (sc->need_ack)
TWSI_WRITE(sc, sc->reg_control,
sc->control_val | TWSI_CONTROL_IFLG);
default:
debugf(sc->dev, "status=%x hot handled\n", status);
sc->transfer = 0;
sc->error = ENXIO;
sc->control_val = 0;
wakeup(sc);
break;
}
debugf(sc->dev, "Done with interrupts\n");
debugf(sc->dev, "Done with interrupts\n\n");
if (transfer_done == 1) {
sc->transfer = 0;
wakeup(sc);

4
sys/dev/iicbus/twsi/twsi.h
View File

@ -57,7 +57,9 @@ struct twsi_softc {
void * intrhand;
bool have_intr;
struct iic_msg *msg;
struct iic_msg *msgs;
uint32_t nmsgs;
uint32_t msg_idx;
uint16_t sent_bytes;
uint16_t recv_bytes;
int transfer;