void unregister_c_can_dev(struct net_device *dev)
{
struct c_can_priv *priv = netdev_priv(dev);
/* disable all interrupts */
c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
unregister_candev(dev);
}
static void c_can_stop(struct net_device *dev)
{
struct c_can_priv *priv = netdev_priv(dev);
/* disable all interrupts */
c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
/* set the state as STOPPED */
priv->can.state = CAN_STATE_STOPPED;
}
static void c_can_start(struct net_device *dev)
{
struct c_can_priv *priv = netdev_priv(dev);
/* basic c_can configuration */
c_can_chip_config(dev);
priv->can.state = CAN_STATE_ERROR_ACTIVE;
/* reset tx helper pointers */
priv->tx_next = priv->tx_echo = 0;
/* enable status change, error and module interrupts */
c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);
}
static irqreturn_t c_can_isr(int irq, void *dev_id)
{
struct net_device *dev = (struct net_device *)dev_id;
struct c_can_priv *priv = netdev_priv(dev);
priv->irqstatus = priv->read_reg(priv, C_CAN_INT_REG);
if (!priv->irqstatus)
return IRQ_NONE;
/* disable all interrupts and schedule the NAPI */
c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
napi_schedule(&priv->napi);
return IRQ_HANDLED;
}
static int c_can_handle_state_change(struct net_device *dev,
enum c_can_bus_error_types error_type)
{
unsigned int reg_err_counter;
unsigned int rx_err_passive;
struct c_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
struct can_berr_counter bec;
/* propagate the error condition to the CAN stack */
skb = alloc_can_err_skb(dev, &cf);
if (unlikely(!skb))
return 0;
c_can_get_berr_counter(dev, &bec);
reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
rx_err_passive = (reg_err_counter & ERR_CNT_RP_MASK) >>
ERR_CNT_RP_SHIFT;
switch (error_type) {
case C_CAN_ERROR_WARNING:
/* error warning state */
priv->can.can_stats.error_warning++;
priv->can.state = CAN_STATE_ERROR_WARNING;
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = (bec.txerr > bec.rxerr) ?
CAN_ERR_CRTL_TX_WARNING :
CAN_ERR_CRTL_RX_WARNING;
cf->data[6] = bec.txerr;
cf->data[7] = bec.rxerr;
break;
case C_CAN_ERROR_PASSIVE:
/* error passive state */
priv->can.can_stats.error_passive++;
priv->can.state = CAN_STATE_ERROR_PASSIVE;
cf->can_id |= CAN_ERR_CRTL;
if (rx_err_passive)
cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
if (bec.txerr > 127)
cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
cf->data[6] = bec.txerr;
cf->data[7] = bec.rxerr;
break;
case C_CAN_BUS_OFF:
/* bus-off state */
priv->can.state = CAN_STATE_BUS_OFF;
cf->can_id |= CAN_ERR_BUSOFF;
/*
* disable all interrupts in bus-off mode to ensure that
* the CPU is not hogged down
*/
c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
can_bus_off(dev);
break;
default:
break;
}
netif_receive_skb(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
return 1;
}
static int c_can_poll(struct napi_struct *napi, int quota)
{
u16 irqstatus;
int lec_type = 0;
int work_done = 0;
struct net_device *dev = napi->dev;
struct c_can_priv *priv = netdev_priv(dev);
irqstatus = priv->irqstatus;
if (!irqstatus)
goto end;
/* status events have the highest priority */
if (irqstatus == STATUS_INTERRUPT) {
priv->current_status = priv->read_reg(priv,
C_CAN_STS_REG);
/* handle Tx/Rx events */
if (priv->current_status & STATUS_TXOK)
priv->write_reg(priv, C_CAN_STS_REG,
priv->current_status & ~STATUS_TXOK);
if (priv->current_status & STATUS_RXOK)
priv->write_reg(priv, C_CAN_STS_REG,
priv->current_status & ~STATUS_RXOK);
/* handle state changes */
if ((priv->current_status & STATUS_EWARN) &&
(!(priv->last_status & STATUS_EWARN))) {
netdev_dbg(dev, "entered error warning state\n");
work_done += c_can_handle_state_change(dev,
C_CAN_ERROR_WARNING);
}
if ((priv->current_status & STATUS_EPASS) &&
(!(priv->last_status & STATUS_EPASS))) {
netdev_dbg(dev, "entered error passive state\n");
work_done += c_can_handle_state_change(dev,
C_CAN_ERROR_PASSIVE);
}
if ((priv->current_status & STATUS_BOFF) &&
(!(priv->last_status & STATUS_BOFF))) {
netdev_dbg(dev, "entered bus off state\n");
work_done += c_can_handle_state_change(dev,
C_CAN_BUS_OFF);
}
/* handle bus recovery events */
if ((!(priv->current_status & STATUS_BOFF)) &&
(priv->last_status & STATUS_BOFF)) {
netdev_dbg(dev, "left bus off state\n");
priv->can.state = CAN_STATE_ERROR_ACTIVE;
}
if ((!(priv->current_status & STATUS_EPASS)) &&
(priv->last_status & STATUS_EPASS)) {
netdev_dbg(dev, "left error passive state\n");
priv->can.state = CAN_STATE_ERROR_ACTIVE;
}
priv->last_status = priv->current_status;
/* handle lec errors on the bus */
lec_type = c_can_has_and_handle_berr(priv);
if (lec_type)
work_done += c_can_handle_bus_err(dev, lec_type);
} else if ((irqstatus >= C_CAN_MSG_OBJ_RX_FIRST) &&
(irqstatus <= C_CAN_MSG_OBJ_RX_LAST)) {
/* handle events corresponding to receive message objects */
work_done += c_can_do_rx_poll(dev, (quota - work_done));
} else if ((irqstatus >= C_CAN_MSG_OBJ_TX_FIRST) &&
(irqstatus <= C_CAN_MSG_OBJ_TX_LAST)) {
/* handle events corresponding to transmit message objects */
c_can_do_tx(dev);
}
end:
if (work_done < quota) {
napi_complete(napi);
/* enable all IRQs */
c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);
}
return work_done;
}
