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can: dev: add can_state_get_by_berr_counter() to return the CAN state based on the current error counters

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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@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde 2023-09-28 09:24:28 +02:00
parent 2f0382a759
commit 9beebc2b5d
2 changed files with 26 additions and 0 deletions
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22
drivers/net/can/dev/dev.c
View File

@ -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)
{

4
include/linux/can/dev.h
View File

@ -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);