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can: rcar_canfd: Add back-to-error-active support

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As per Wolfgang G, all new drivers should support decreasing state
transition(back-to-error-active). This patch adds this support.

This driver configures the controller to halt on bus-off entry. Hence,
when in error states less than bus off state, the TEC/REC counters
are checked for lower state transition eligibility and action.

Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Ramesh Shanmugasundaram 2016-06-22 13:31:47 +01:00 committed by Marc Kleine-Budde
parent 6f4c2eea35
commit 926f10359a
1 changed files with 56 additions and 20 deletions
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76
drivers/net/can/rcar/rcar_canfd.c
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@ -917,16 +917,17 @@ static void rcar_canfd_global_error(struct net_device *ndev)
rcar_canfd_write(priv->base, RCANFD_GERFL, 0);
}
static void rcar_canfd_error(struct net_device *ndev)
static void rcar_canfd_error(struct net_device *ndev, u32 cerfl,
u16 txerr, u16 rxerr)
{
struct rcar_canfd_channel *priv = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
struct can_frame *cf;
struct sk_buff *skb;
u32 cerfl, csts;
u32 txerr = 0, rxerr = 0;
u32 ch = priv->channel;
netdev_dbg(ndev, "ch erfl %x txerr %u rxerr %u\n", cerfl, txerr, rxerr);
/* Propagate the error condition to the CAN stack */
skb = alloc_can_err_skb(ndev, &cf);
if (!skb) {
@ -934,15 +935,7 @@ static void rcar_canfd_error(struct net_device *ndev)
return;
}
/* Channel error interrupt */
cerfl = rcar_canfd_read(priv->base, RCANFD_CERFL(ch));
csts = rcar_canfd_read(priv->base, RCANFD_CSTS(ch));
txerr = RCANFD_CSTS_TECCNT(csts);
rxerr = RCANFD_CSTS_RECCNT(csts);
netdev_dbg(ndev, "ch erfl %x sts %x txerr %u rxerr %u\n",
cerfl, csts, txerr, rxerr);
/* Channel error interrupts */
if (cerfl & RCANFD_CERFL_BEF) {
netdev_dbg(ndev, "Bus error\n");
cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
@ -1032,8 +1025,9 @@ static void rcar_canfd_error(struct net_device *ndev)
cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
}
/* Clear all channel error interrupts */
rcar_canfd_write(priv->base, RCANFD_CERFL(ch), 0);
/* Clear channel error interrupts that are handled */
rcar_canfd_write(priv->base, RCANFD_CERFL(ch),
RCANFD_CERFL_ERR(~cerfl));
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_rx(skb);
@ -1098,12 +1092,12 @@ static irqreturn_t rcar_canfd_global_interrupt(int irq, void *dev_id)
/* Global error interrupts */
gerfl = rcar_canfd_read(priv->base, RCANFD_GERFL);
if (RCANFD_GERFL_ERR(gpriv, gerfl))
if (unlikely(RCANFD_GERFL_ERR(gpriv, gerfl)))
rcar_canfd_global_error(ndev);
/* Handle Rx interrupts */
sts = rcar_canfd_read(priv->base, RCANFD_RFSTS(ridx));
if (sts & RCANFD_RFSTS_RFIF) {
if (likely(sts & RCANFD_RFSTS_RFIF)) {
if (napi_schedule_prep(&priv->napi)) {
/* Disable Rx FIFO interrupts */
rcar_canfd_clear_bit(priv->base,
@ -1116,12 +1110,46 @@ static irqreturn_t rcar_canfd_global_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
static void rcar_canfd_state_change(struct net_device *ndev,
u16 txerr, u16 rxerr)
{
struct rcar_canfd_channel *priv = netdev_priv(ndev);
struct net_device_stats *stats = &ndev->stats;
enum can_state rx_state, tx_state, state = priv->can.state;
struct can_frame *cf;
struct sk_buff *skb;
/* Handle transition from error to normal states */
if (txerr < 96 && rxerr < 96)
state = CAN_STATE_ERROR_ACTIVE;
else if (txerr < 128 && rxerr < 128)
state = CAN_STATE_ERROR_WARNING;
if (state != priv->can.state) {
netdev_dbg(ndev, "state: new %d, old %d: txerr %u, rxerr %u\n",
state, priv->can.state, txerr, rxerr);
skb = alloc_can_err_skb(ndev, &cf);
if (!skb) {
stats->rx_dropped++;
return;
}
tx_state = txerr >= rxerr ? state : 0;
rx_state = txerr <= rxerr ? state : 0;
can_change_state(ndev, cf, tx_state, rx_state);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
netif_rx(skb);
}
}
static irqreturn_t rcar_canfd_channel_interrupt(int irq, void *dev_id)
{
struct rcar_canfd_global *gpriv = dev_id;
struct net_device *ndev;
struct rcar_canfd_channel *priv;
u32 sts, cerfl, ch;
u32 sts, ch, cerfl;
u16 txerr, rxerr;
/* Common FIFO is a per channel resource */
for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
@ -1130,13 +1158,21 @@ static irqreturn_t rcar_canfd_channel_interrupt(int irq, void *dev_id)
/* Channel error interrupts */
cerfl = rcar_canfd_read(priv->base, RCANFD_CERFL(ch));
if (RCANFD_CERFL_ERR(cerfl))
rcar_canfd_error(ndev);
sts = rcar_canfd_read(priv->base, RCANFD_CSTS(ch));
txerr = RCANFD_CSTS_TECCNT(sts);
rxerr = RCANFD_CSTS_RECCNT(sts);
if (unlikely(RCANFD_CERFL_ERR(cerfl)))
rcar_canfd_error(ndev, cerfl, txerr, rxerr);
/* Handle state change to lower states */
if (unlikely((priv->can.state != CAN_STATE_ERROR_ACTIVE) &&
(priv->can.state != CAN_STATE_BUS_OFF)))
rcar_canfd_state_change(ndev, txerr, rxerr);
/* Handle Tx interrupts */
sts = rcar_canfd_read(priv->base,
RCANFD_CFSTS(ch, RCANFD_CFFIFO_IDX));
if (sts & RCANFD_CFSTS_CFTXIF)
if (likely(sts & RCANFD_CFSTS_CFTXIF))
rcar_canfd_tx_done(ndev);
}
return IRQ_HANDLED;