enic: feature add: add ethtool -c/C support

Only rx_usec and tx_usec options for ethtool -C are settable as those
are the only settings that make sense to HW.  Adds driver reporting of
intr coalescing timer value in usec units rather than HW units.

Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/enic/vnic_intr.c b/drivers/net/enic/vnic_intr.c
index 1f8786d..3934309 100644
--- a/drivers/net/enic/vnic_intr.c
+++ b/drivers/net/enic/vnic_intr.c
@@ -50,12 +50,18 @@
 void vnic_intr_init(struct vnic_intr *intr, unsigned int coalescing_timer,
 	unsigned int coalescing_type, unsigned int mask_on_assertion)
 {
-	iowrite32(coalescing_timer, &intr->ctrl->coalescing_timer);
+	vnic_intr_coalescing_timer_set(intr, coalescing_timer);
 	iowrite32(coalescing_type, &intr->ctrl->coalescing_type);
 	iowrite32(mask_on_assertion, &intr->ctrl->mask_on_assertion);
 	iowrite32(0, &intr->ctrl->int_credits);
 }
 
+void vnic_intr_coalescing_timer_set(struct vnic_intr *intr,
+	unsigned int coalescing_timer)
+{
+	iowrite32(coalescing_timer, &intr->ctrl->coalescing_timer);
+}
+
 void vnic_intr_clean(struct vnic_intr *intr)
 {
 	iowrite32(0, &intr->ctrl->int_credits);