[PATCH net-next-2.6 v9 08/20] pch_can: Reduce register access

Tomoya MORINAGA
2010-12-13T06:25:27Z

For improve tx/rx speed, reduce register access.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
---
drivers/net/can/pch_can.c | 55 +++++++++++++++++---------------------------
1 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index c6c0842..0acc877 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -372,9 +372,6 @@ static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
pch_can_bit_set(&priv->regs->ifregs[0].mcont,
PCH_IF_MCONT_UMASK);

- /* Set FIFO mode set to 0 except last Rx Obj*/
- pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
- PCH_IF_MCONT_EOB);
/* In case FIFO mode, Last EoB of Rx Obj must be 1 */
if (i == PCH_RX_OBJ_END)
pch_can_bit_set(&priv->regs->ifregs[0].mcont,
@@ -402,14 +399,11 @@ static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)

/* Resetting DIR bit for reception */
iowrite32(0x0, &priv->regs->ifregs[1].id1);
- iowrite32(0x0, &priv->regs->ifregs[1].id2);
- pch_can_bit_set(&priv->regs->ifregs[1].id2, PCH_ID2_DIR);
+ iowrite32(PCH_ID2_DIR, &priv->regs->ifregs[1].id2);

/* Setting EOB bit for transmitter */
- iowrite32(PCH_IF_MCONT_EOB, &priv->regs->ifregs[1].mcont);
-
- pch_can_bit_set(&priv->regs->ifregs[1].mcont,
- PCH_IF_MCONT_UMASK);
+ iowrite32(PCH_IF_MCONT_EOB | PCH_IF_MCONT_UMASK,
+ &priv->regs->ifregs[1].mcont);

iowrite32(0, &priv->regs->ifregs[1].mask1);
pch_can_bit_clear(&priv->regs->ifregs[1].mask2, 0x1fff);
@@ -524,12 +518,12 @@ static void pch_can_error(struct net_device *ndev, u32 status)
dev_err(&ndev->dev, "%s -> Bus Off occurres.\n", __func__);
}

+ errc = ioread32(&priv->regs->errc);
/* Warning interrupt. */
if (status & PCH_EWARN) {
state = CAN_STATE_ERROR_WARNING;
priv->can.can_stats.error_warning++;
cf->can_id |= CAN_ERR_CRTL;
- errc = ioread32(&priv->regs->errc);
if (((errc & PCH_REC) >> 8) > 96)
cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
if ((errc & PCH_TEC) > 96)
@@ -542,7 +536,6 @@ static void pch_can_error(struct net_device *ndev, u32 status)
priv->can.can_stats.error_passive++;
state = CAN_STATE_ERROR_PASSIVE;
cf->can_id |= CAN_ERR_CRTL;
- errc = ioread32(&priv->regs->errc);
if (((errc & PCH_REC) >> 8) > 127)
cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
if ((errc & PCH_TEC) > 127)
@@ -927,6 +920,7 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
struct can_frame *cf = (struct can_frame *)skb->data;
int tx_obj_no;
int i;
+ u32 id2;

if (can_dropped_invalid_skb(ndev, skb))
return NETDEV_TX_OK;
@@ -950,22 +944,23 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
pch_can_bit_set(&priv->regs->ifregs[1].cmask, PCH_CMASK_ALL);

/* If ID extended is set. */
- pch_can_bit_clear(&priv->regs->ifregs[1].id1, 0xffff);
- pch_can_bit_clear(&priv->regs->ifregs[1].id2, 0x1fff | PCH_ID2_XTD);
if (cf->can_id & CAN_EFF_FLAG) {
- pch_can_bit_set(&priv->regs->ifregs[1].id1,
- cf->can_id & 0xffff);
- pch_can_bit_set(&priv->regs->ifregs[1].id2,
- ((cf->can_id >> 16) & 0x1fff) | PCH_ID2_XTD);
+ iowrite32(cf->can_id & 0xffff, &priv->regs->ifregs[1].id1);
+ id2 = ((cf->can_id >> 16) & 0x1fff) | PCH_ID2_XTD;
} else {
- pch_can_bit_set(&priv->regs->ifregs[1].id1, 0);
- pch_can_bit_set(&priv->regs->ifregs[1].id2,
- (cf->can_id & CAN_SFF_MASK) << 2);
+ iowrite32(0, &priv->regs->ifregs[1].id1);
+ id2 = (cf->can_id & CAN_SFF_MASK) << 2;
}

+ id2 |= PCH_ID_MSGVAL;
+
/* If remote frame has to be transmitted.. */
if (cf->can_id & CAN_RTR_FLAG)
- pch_can_bit_clear(&priv->regs->ifregs[1].id2, PCH_ID2_DIR);
+ id2 &= ~PCH_ID2_DIR;
+ else
+ id2 |= PCH_ID2_DIR;
+
+ iowrite32(id2, &priv->regs->ifregs[1].id2);

/* Copy data to register */
for (i = 0; i < cf->can_dlc; i += 2) {
@@ -976,17 +971,8 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
can_put_echo_skb(skb, ndev, tx_obj_no - PCH_RX_OBJ_END - 1);

/* Updating the size of the data. */
- pch_can_bit_clear(&priv->regs->ifregs[1].mcont, 0x0f);
- pch_can_bit_set(&priv->regs->ifregs[1].mcont, cf->can_dlc);
-
- /* Clearing IntPend, NewDat & TxRqst */
- pch_can_bit_clear(&priv->regs->ifregs[1].mcont,
- PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND |
- PCH_IF_MCONT_TXRQXT);
-
- /* Setting NewDat, TxRqst bits */
- pch_can_bit_set(&priv->regs->ifregs[1].mcont,
- PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_TXRQXT);
+ iowrite32(cf->can_dlc | PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_TXRQXT |
+ PCH_IF_MCONT_TXIE, &priv->regs->ifregs[1].mcont);

pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);

@@ -1211,9 +1197,10 @@ static int pch_can_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct pch_can_priv *priv = netdev_priv(dev);
+ u32 errc = ioread32(&priv->regs->errc);

- bec->txerr = ioread32(&priv->regs->errc) & PCH_TEC;
- bec->rxerr = (ioread32(&priv->regs->errc) & PCH_REC) >> 8;
+ bec->txerr = errc & PCH_TEC;
+ bec->rxerr = (errc & PCH_REC) >> 8;

return 0;
}
--
1.6.0.6