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Fix LPC17 CAN driver; TX must be interrupt driven

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4290 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2012-01-10 22:29:39 +00:00
parent 727334a181
commit 6bcadeb699
1 changed files with 90 additions and 28 deletions
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118
arch/arm/src/lpc17xx/lpc17_can.c
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@ -203,6 +203,7 @@ static void can_txint(FAR struct can_dev_s *dev, bool enable);
static int can_ioctl(FAR struct can_dev_s *dev, int cmd, unsigned long arg); static int can_ioctl(FAR struct can_dev_s *dev, int cmd, unsigned long arg);
static int can_remoterequest(FAR struct can_dev_s *dev, uint16_t id); static int can_remoterequest(FAR struct can_dev_s *dev, uint16_t id);
static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg); static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg);
static bool can_txready(FAR struct can_dev_s *dev);
static bool can_txempty(FAR struct can_dev_s *dev); static bool can_txempty(FAR struct can_dev_s *dev);
/* CAN interrupts */ /* CAN interrupts */
@ -228,6 +229,7 @@ static const struct can_ops_s g_canops =
.co_ioctl = can_ioctl, .co_ioctl = can_ioctl,
.co_remoterequest = can_remoterequest, .co_remoterequest = can_remoterequest,
.co_send = can_send, .co_send = can_send,
.co_txready = can_txready,
.co_txempty = can_txempty, .co_txempty = can_txempty,
}; };
@ -739,6 +741,19 @@ static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
regval = can_getreg(priv, LPC17_CAN_SR_OFFSET); regval = can_getreg(priv, LPC17_CAN_SR_OFFSET);
if ((regval & CAN_SR_TBS1) != 0) if ((regval & CAN_SR_TBS1) != 0)
{ {
/* Make sure that buffer 1 TX interrupts are enabled BEFORE sending the
* message. The TX interrupt is generated when the TBSn bit in CANxSR
* goes from 0 to 1 when the TIEn bit in CANxIER is 1. If we don't
* enable it now, we may miss the TIE1 interrupt.
*
* NOTE: The IER is also modified from the interrupt handler, but the
* following is safe because interrupts are disabled here.
*/
regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
regval |= CAN_IER_TIE1;
can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
/* Set up the transfer */ /* Set up the transfer */
can_putreg(priv, LPC17_CAN_TFI1_OFFSET, tfi); can_putreg(priv, LPC17_CAN_TFI1_OFFSET, tfi);
@ -753,16 +768,23 @@ static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
#else #else
can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB1 | CAN_CMR_TR); can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB1 | CAN_CMR_TR);
#endif #endif
/* Tell the caller that the transfer is done. It isn't, but we have
* more transmit buffers and this can speed things up.
*/
can_txdone(dev);
} }
else if ((regval & CAN_SR_TBS2) != 0) else if ((regval & CAN_SR_TBS2) != 0)
{ {
/* Set up the transfer */ /* Make sure that buffer 2 TX interrupts are enabled BEFORE sending the
* message. The TX interrupt is generated when the TBSn bit in CANxSR
* goes from 0 to 1 when the TIEn bit in CANxIER is 1. If we don't
* enable it now, we may miss the TIE2 interrupt.
*
* NOTE: The IER is also modified from the interrupt handler, but the
* following is safe because interrupts are disabled here.
*/
regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
regval |= CAN_IER_TIE2;
can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
/* Set up the transfer */
can_putreg(priv, LPC17_CAN_TFI2_OFFSET, tfi); can_putreg(priv, LPC17_CAN_TFI2_OFFSET, tfi);
can_putreg(priv, LPC17_CAN_TID2_OFFSET, tid); can_putreg(priv, LPC17_CAN_TID2_OFFSET, tid);
@ -776,29 +798,20 @@ static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
#else #else
can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB2 | CAN_CMR_TR); can_putreg(priv, LPC17_CAN_CMR_OFFSET, CAN_CMR_STB2 | CAN_CMR_TR);
#endif #endif
/* Tell the caller that the transfer is done. It isn't, but we have
* more transmit buffers and this can speed things up.
*/
can_txdone(dev);
} }
else if ((regval & CAN_SR_TBS3) != 0) else if ((regval & CAN_SR_TBS3) != 0)
{ {
/* We have no more buffers. We will make the caller wait. First, make /* Make sure that buffer 3 TX interrupts are enabled BEFORE sending the
* sure that all buffer 3 interrupts are enabled BEFORE sending the * message. The TX interrupt is generated when the TBSn bit in CANxSR
* message. The TX interrupt is generated TBSn bit in CANxSR goes from 0 * goes from 0 to 1 when the TIEn bit in CANxIER is 1. If we don't
* to 1 when the TIEn bit in CANxIER is 1. If we don't enable it now, * enable it now, we may miss the TIE3 interrupt.
* we will miss the TIE3 interrupt. We enable ALL TIE interrupts here
* because we don't care which one finishes: When first one finishes it
* means that a transmit buffer is again available.
* *
* NOTE: The IER is also modified from the interrupt handler, but the * NOTE: The IER is also modified from the interrupt handler, but the
* following is safe because interrupts are disabled here. * following is safe because interrupts are disabled here.
*/ */
regval = can_getreg(priv, LPC17_CAN_IER_OFFSET); regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
regval |= (CAN_IER_TIE1 | CAN_IER_TIE2 | CAN_IER_TIE3); regval |= CAN_IER_TIE3;
can_putreg(priv, LPC17_CAN_IER_OFFSET, regval); can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
/* Set up the transfer */ /* Set up the transfer */
@ -826,6 +839,27 @@ static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
return ret; return ret;
} }
/****************************************************************************
* Name: can_txready
*
* Description:
* Return true if the CAN hardware can accept another TX message.
*
* Input Parameters:
* dev - An instance of the "upper half" can driver state structure.
*
* Returned Value:
* True is the CAN hardware is ready to accept another TX message.
*
****************************************************************************/
static bool can_txready(FAR struct can_dev_s *dev)
{
FAR struct up_dev_s *priv = (FAR struct up_dev_s *)dev->cd_priv;
uint32_t regval = can_getreg(priv, LPC17_CAN_SR_OFFSET);
return ((regval & (CAN_SR_TBS1 | CAN_SR_TBS2 | CAN_SR_TBS3)) != 0);
}
/**************************************************************************** /****************************************************************************
* Name: can_txempty * Name: can_txempty
* *
@ -840,7 +874,7 @@ static int can_send(FAR struct can_dev_s *dev, FAR struct can_msg_s *msg)
* dev - An instance of the "upper half" can driver state structure. * dev - An instance of the "upper half" can driver state structure.
* *
* Returned Value: * Returned Value:
* Zero on success; a negated errno on failure * True is there are no pending TX transfers in the CAN hardware.
* *
****************************************************************************/ ****************************************************************************/
@ -907,16 +941,44 @@ static void can_interrupt(FAR struct can_dev_s *dev)
can_receive(dev, hdr, (uint8_t *)data); can_receive(dev, hdr, (uint8_t *)data);
} }
/* Check for a transmit interrupt from buffer 1, 2, or 3 meaning that at /* Check for TX buffer 1 complete */
* least one TX is complete and that at least one TX buffer is available.
*/
if ((regval & (CAN_ICR_TI1 | CAN_ICR_TI2 |CAN_ICR_TI3)) != 0) if ((regval & CAN_ICR_TI1) != 0)
{ {
/* Disable all further TX interrupts */ /* Disable all further TX buffer 1 interrupts */
regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
regval &= ~CAN_IER_TIE1;
can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
/* Indicate that the TX is done and a new TX buffer is available */
can_txdone(dev);
}
/* Check for TX buffer 2 complete */
if ((regval & CAN_ICR_TI2) != 0)
{
/* Disable all further TX buffer 2 interrupts */
regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
regval &= ~CAN_IER_TIE2;
can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
/* Indicate that the TX is done and a new TX buffer is available */
can_txdone(dev);
}
/* Check for TX buffer 3 complete */
if ((regval & CAN_ICR_TI3) != 0)
{
/* Disable all further TX buffer 3 interrupts */
regval = can_getreg(priv, LPC17_CAN_IER_OFFSET); regval = can_getreg(priv, LPC17_CAN_IER_OFFSET);
regval &= ~(CAN_IER_TIE1 | CAN_IER_TIE2 | CAN_IER_TIE3); regval &= ~CAN_IER_TIE3;
can_putreg(priv, LPC17_CAN_IER_OFFSET, regval); can_putreg(priv, LPC17_CAN_IER_OFFSET, regval);
/* Indicate that the TX is done and a new TX buffer is available */ /* Indicate that the TX is done and a new TX buffer is available */