can: netlink support for bus-error reporting and counters

This patch makes the bus-error reporting configurable and allows to
retrieve the CAN TX and RX bus error counters via netlink interface.
I have added support for the SJA1000. The TX and RX bus error counters
are also copied to the data fields 6..7 of error messages when state
changes are reported.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 28 insertions, 3 deletions

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index f08f1202ff00..904aa369f80e 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -574,6 +574,7 @@ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
         [IFLA_CAN_BITTIMING_CONST]
                                 = { .len = sizeof(struct can_bittiming_const) },
         [IFLA_CAN_CLOCK]        = { .len = sizeof(struct can_clock) },
+        [IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
 };
 
 static int can_changelink(struct net_device *dev,
@@ -649,6 +650,8 @@ static size_t can_get_size(const struct net_device *dev)
         size += nla_total_size(sizeof(u32));  /* IFLA_CAN_RESTART_MS */
         size += sizeof(struct can_bittiming); /* IFLA_CAN_BITTIMING */
         size += sizeof(struct can_clock);     /* IFLA_CAN_CLOCK */
+        if (priv->do_get_berr_counter)        /* IFLA_CAN_BERR_COUNTER */
+                size += sizeof(struct can_berr_counter);
         if (priv->bittiming_const)            /* IFLA_CAN_BITTIMING_CONST */
                 size += sizeof(struct can_bittiming_const);
 
@@ -659,6 +662,7 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
         struct can_priv *priv = netdev_priv(dev);
         struct can_ctrlmode cm = {.flags = priv->ctrlmode};
+        struct can_berr_counter bec;
         enum can_state state = priv->state;
 
         if (priv->do_get_state)
@@ -669,6 +673,8 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
         NLA_PUT(skb, IFLA_CAN_BITTIMING,
                 sizeof(priv->bittiming), &priv->bittiming);
         NLA_PUT(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock);
+        if (priv->do_get_berr_counter && !priv->do_get_berr_counter(dev, &bec))
+                NLA_PUT(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec);
         if (priv->bittiming_const)
                 NLA_PUT(skb, IFLA_CAN_BITTIMING_CONST,
                         sizeof(*priv->bittiming_const), priv->bittiming_const);
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index ace103a44833..145b1a731a53 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -130,8 +130,12 @@ static void set_normal_mode(struct net_device *dev)
                 /* check reset bit */
                 if ((status & MOD_RM) == 0) {
                         priv->can.state = CAN_STATE_ERROR_ACTIVE;
-                        /* enable all interrupts */
-                        priv->write_reg(priv, REG_IER, IRQ_ALL);
+                        /* enable interrupts */
+                        if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+                                priv->write_reg(priv, REG_IER, IRQ_ALL);
+                        else
+                                priv->write_reg(priv, REG_IER,
+                                                IRQ_ALL & ~IRQ_BEI);
                         return;
                 }
 
@@ -203,6 +207,17 @@ static int sja1000_set_bittiming(struct net_device *dev)
         return 0;
 }
 
+static int sja1000_get_berr_counter(const struct net_device *dev,
+                                    struct can_berr_counter *bec)
+{
+        struct sja1000_priv *priv = netdev_priv(dev);
+
+        bec->txerr = priv->read_reg(priv, REG_TXERR);
+        bec->rxerr = priv->read_reg(priv, REG_RXERR);
+
+        return 0;
+}
+
 /*
  * initialize SJA1000 chip:
  *   - reset chip
@@ -437,6 +452,8 @@ static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
                                 CAN_ERR_CRTL_TX_PASSIVE :
                                 CAN_ERR_CRTL_RX_PASSIVE;
                 }
+                cf->data[6] = txerr;
+                cf->data[7] = rxerr;
         }
 
         priv->can.state = state;
@@ -567,7 +584,9 @@ struct net_device *alloc_sja1000dev(int sizeof_priv)
         priv->can.bittiming_const = &sja1000_bittiming_const;
         priv->can.do_set_bittiming = sja1000_set_bittiming;
         priv->can.do_set_mode = sja1000_set_mode;
-        priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
+        priv->can.do_get_berr_counter = sja1000_get_berr_counter;
+        priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
+                CAN_CTRLMODE_BERR_REPORTING;
 
         if (sizeof_priv)
                 priv->priv = (void *)priv + sizeof(struct sja1000_priv);