/*
* theory of operation:
*
* priv->tx_echo holds the number of the oldest can_frame put for
* transmission into the hardware, but not yet ACKed by the CAN tx
* complete IRQ.
*
* We iterate from priv->tx_echo to priv->tx_next and check if the
* packet has been transmitted, echo it back to the CAN framework.
* If we discover a not yet transmitted packet, stop looking for more.
*/
static void c_can_do_tx(struct net_device *dev)
{
u32 val;
u32 msg_obj_no;
struct c_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
msg_obj_no = get_tx_echo_msg_obj(priv);
val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG);
if (!(val & (1 << (msg_obj_no - 1)))) {
can_get_echo_skb(dev,
msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
stats->tx_bytes += priv->read_reg(priv,
C_CAN_IFACE(MSGCTRL_REG, 0))
& IF_MCONT_DLC_MASK;
stats->tx_packets++;
can_led_event(dev, CAN_LED_EVENT_TX);
c_can_inval_msg_object(dev, 0, msg_obj_no);
} else {
break;
}
}
/* restart queue if wrap-up or if queue stalled on last pkt */
if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) ||
((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0))
netif_wake_queue(dev);
}
/*
* theory of operation:
*
* priv->tx_echo holds the number of the oldest can_frame put for
* transmission into the hardware, but not yet ACKed by the CAN tx
* complete IRQ.
*
* We iterate from priv->tx_echo to priv->tx_next and check if the
* packet has been transmitted, echo it back to the CAN framework.
* If we discover a not yet transmitted package, stop looking for more.
*/
static void c_can_do_tx(struct net_device *dev)
{
u32 val;
u32 msg_obj_no;
struct c_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
msg_obj_no = get_tx_echo_msg_obj(priv);
val = c_can_read_reg32(priv, &priv->regs->txrqst1);
if (!(val & (1 << msg_obj_no))) {
can_get_echo_skb(dev,
msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
stats->tx_bytes += priv->read_reg(priv,
&priv->regs->ifregs[0].msg_cntrl)
& IF_MCONT_DLC_MASK;
stats->tx_packets++;
c_can_inval_msg_object(dev, 0, msg_obj_no);
}
}
/* restart queue if wrap-up or if queue stalled on last pkt */
if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) ||
((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0))
netif_wake_queue(dev);
}
static void c_can_setup_tx_object(struct net_device *dev, int iface,
struct can_frame *frame, int idx)
{
struct c_can_priv *priv = netdev_priv(dev);
u16 ctrl = IF_MCONT_TX | frame->can_dlc;
bool rtr = frame->can_id & CAN_RTR_FLAG;
u32 arb = IF_ARB_MSGVAL;
int i;
if (frame->can_id & CAN_EFF_FLAG) {
arb |= frame->can_id & CAN_EFF_MASK;
arb |= IF_ARB_MSGXTD;
} else {
arb |= (frame->can_id & CAN_SFF_MASK) << 18;
}
if (!rtr)
arb |= IF_ARB_TRANSMIT;
/*
* If we change the DIR bit, we need to invalidate the buffer
* first, i.e. clear the MSGVAL flag in the arbiter.
*/
if (rtr != (bool)test_bit(idx, &priv->tx_dir)) {
u32 obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
c_can_inval_msg_object(dev, iface, obj);
change_bit(idx, &priv->tx_dir);
}
priv->write_reg32(priv, C_CAN_IFACE(ARB1_REG, iface), arb);
priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl);
if (priv->type == BOSCH_D_CAN) {
u32 data = 0, dreg = C_CAN_IFACE(DATA1_REG, iface);
for (i = 0; i < frame->can_dlc; i += 4, dreg += 2) {
data = (u32)frame->data[i];
data |= (u32)frame->data[i + 1] << 8;
data |= (u32)frame->data[i + 2] << 16;
data |= (u32)frame->data[i + 3] << 24;
priv->write_reg32(priv, dreg, data);
}
} else {
for (i = 0; i < frame->can_dlc; i += 2) {
priv->write_reg(priv,
C_CAN_IFACE(DATA1_REG, iface) + i / 2,
frame->data[i] |
(frame->data[i + 1] << 8));
}
}
}
/*
* Configure C_CAN message objects for Tx and Rx purposes:
* C_CAN provides a total of 32 message objects that can be configured
* either for Tx or Rx purposes. Here the first 16 message objects are used as
* a reception FIFO. The end of reception FIFO is signified by the EoB bit
* being SET. The remaining 16 message objects are kept aside for Tx purposes.
* See user guide document for further details on configuring message
* objects.
*/
static void c_can_configure_msg_objects(struct net_device *dev)
{
int i;
/* first invalidate all message objects */
for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_NO_OF_OBJECTS; i++)
c_can_inval_msg_object(dev, IF_RX, i);
/* setup receive message objects */
for (i = C_CAN_MSG_OBJ_RX_FIRST; i < C_CAN_MSG_OBJ_RX_LAST; i++)
c_can_setup_receive_object(dev, IF_RX, i, 0, 0, IF_MCONT_RCV);
c_can_setup_receive_object(dev, IF_RX, C_CAN_MSG_OBJ_RX_LAST, 0, 0,
IF_MCONT_RCV_EOB);
}
