On Wed. 4 Oct. 2023, 18:24, Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> wrote:
> 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..6242424fadbc 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 < 96)
> + return CAN_STATE_ERROR_ACTIVE;
> + if (err < 128)
> + return CAN_STATE_ERROR_WARNING;
> + if (err < 256)
> + return CAN_STATE_ERROR_PASSIVE;
Please use the macros from include/uapi/linux/can/error.h.
https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/can/error.h#L130
> + 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);
