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. Link: https://lore.kernel.org/all/20231005-at91_can-rx_offload-v2-1-9987d53600e0@xxxxxxxxxxxxxx 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 82b12902fc35..3a3be5cdfc1f 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
