Some CAN controllers do not have a register that contains the current
CAN state, but only a register that contains the error counters.
Introduce a new function can_state_get_by_berr_counter() that returns
the current TX and RX state depending on the provided CAN bit error
counters.
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
drivers/net/can/dev/dev.c | 22 ++++++++++++++++++++++
include/linux/can/dev.h | 4 ++++
2 files changed, 26 insertions(+)
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 7f9334a8af50..a0db1f78d61d 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -90,6 +90,28 @@ const char *can_get_state_str(const enum can_state state)
}
EXPORT_SYMBOL_GPL(can_get_state_str);
+static enum can_state can_state_err_to_state(u16 err)
+{
+ if (err < CAN_ERROR_WARNING_THRESHOLD)
+ return CAN_STATE_ERROR_ACTIVE;
+ if (err < CAN_ERROR_PASSIVE_THRESHOLD)
+ return CAN_STATE_ERROR_WARNING;
+ if (err < CAN_BUS_OFF_THRESHOLD)
+ return CAN_STATE_ERROR_PASSIVE;
+
+ return CAN_STATE_BUS_OFF;
+}
+
+void can_state_get_by_berr_counter(const struct net_device *dev,
+ const struct can_berr_counter *bec,
+ enum can_state *tx_state,
+ enum can_state *rx_state)
+{
+ *tx_state = can_state_err_to_state(bec->txerr);
+ *rx_state = can_state_err_to_state(bec->rxerr);
+}
+EXPORT_SYMBOL_GPL(can_state_get_by_berr_counter);
+
void can_change_state(struct net_device *dev, struct can_frame *cf,
enum can_state tx_state, enum can_state rx_state)
{
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 982ba245eb41..1b92aed49363 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -195,6 +195,10 @@ int can_restart_now(struct net_device *dev);
void can_bus_off(struct net_device *dev);
const char *can_get_state_str(const enum can_state state);
+void can_state_get_by_berr_counter(const struct net_device *dev,
+ const struct can_berr_counter *bec,
+ enum can_state *tx_state,
+ enum can_state *rx_state);
void can_change_state(struct net_device *dev, struct can_frame *cf,
enum can_state tx_state, enum can_state rx_state);
--
2.40.1
