i2c: rcar: init new messages in irq
Setting up new messages was done in process context while handling a message was in interrupt context. Because of the HW design, this IP core is sensitive to timing, so the context switches were too expensive. Move this setup to interrupt context as well. In my test setup, this fixed the occasional 'data byte sent twice' issue which a number of people have seen. It also fixes to send REP_START after a read message which was wrongly send as a STOP + START sequence before. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
parent
344beeb23b
commit
2bc3c5a863
|
@ -266,6 +266,13 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
|
|||
rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
|
||||
}
|
||||
|
||||
static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
|
||||
{
|
||||
priv->msg++;
|
||||
priv->msgs_left--;
|
||||
rcar_i2c_prepare_msg(priv);
|
||||
}
|
||||
|
||||
/*
|
||||
* interrupt functions
|
||||
*/
|
||||
|
@ -308,21 +315,17 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
|
|||
* [ICRXTX] -> [SHIFT] -> [I2C bus]
|
||||
*/
|
||||
|
||||
if (priv->flags & ID_LAST_MSG)
|
||||
if (priv->flags & ID_LAST_MSG) {
|
||||
/*
|
||||
* If current msg is the _LAST_ msg,
|
||||
* prepare stop condition here.
|
||||
* ID_DONE will be set on STOP irq.
|
||||
*/
|
||||
rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
|
||||
else
|
||||
/*
|
||||
* If current msg is _NOT_ last msg,
|
||||
* it doesn't call stop phase.
|
||||
* thus, there is no STOP irq.
|
||||
* return ID_DONE here.
|
||||
*/
|
||||
return ID_DONE;
|
||||
} else {
|
||||
rcar_i2c_next_msg(priv);
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
|
||||
|
@ -366,7 +369,10 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
|
|||
else
|
||||
rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
|
||||
|
||||
rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
|
||||
if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG))
|
||||
rcar_i2c_next_msg(priv);
|
||||
else
|
||||
rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
@ -461,6 +467,7 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
|
|||
|
||||
/* Stop */
|
||||
if (msr & MST) {
|
||||
priv->msgs_left--; /* The last message also made it */
|
||||
rcar_i2c_flags_set(priv, ID_DONE);
|
||||
goto out;
|
||||
}
|
||||
|
@ -500,35 +507,28 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
|
|||
/* This HW can't send STOP after address phase */
|
||||
if (msgs[i].len == 0) {
|
||||
ret = -EOPNOTSUPP;
|
||||
break;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
|
||||
/* init each data */
|
||||
priv->msg = &msgs[i];
|
||||
priv->msgs_left = num - i;
|
||||
/* init data */
|
||||
priv->msg = msgs;
|
||||
priv->msgs_left = num;
|
||||
|
||||
rcar_i2c_prepare_msg(priv);
|
||||
rcar_i2c_prepare_msg(priv);
|
||||
|
||||
time_left = wait_event_timeout(priv->wait,
|
||||
rcar_i2c_flags_has(priv, ID_DONE),
|
||||
adap->timeout);
|
||||
if (!time_left) {
|
||||
rcar_i2c_init(priv);
|
||||
ret = -ETIMEDOUT;
|
||||
break;
|
||||
}
|
||||
|
||||
if (rcar_i2c_flags_has(priv, ID_NACK)) {
|
||||
ret = -ENXIO;
|
||||
break;
|
||||
}
|
||||
|
||||
if (rcar_i2c_flags_has(priv, ID_ARBLOST)) {
|
||||
ret = -EAGAIN;
|
||||
break;
|
||||
}
|
||||
|
||||
ret = i + 1; /* The number of transfer */
|
||||
time_left = wait_event_timeout(priv->wait,
|
||||
rcar_i2c_flags_has(priv, ID_DONE),
|
||||
num * adap->timeout);
|
||||
if (!time_left) {
|
||||
rcar_i2c_init(priv);
|
||||
ret = -ETIMEDOUT;
|
||||
} else if (rcar_i2c_flags_has(priv, ID_NACK)) {
|
||||
ret = -ENXIO;
|
||||
} else if (rcar_i2c_flags_has(priv, ID_ARBLOST)) {
|
||||
ret = -EAGAIN;
|
||||
} else {
|
||||
ret = num - priv->msgs_left; /* The number of transfer */
|
||||
}
|
||||
out:
|
||||
pm_runtime_put(dev);
|
||||
|
|
Loading…
Reference in New Issue