can: rockchip_canfd: add support for CAN_CTRLMODE_LOOPBACK

Add support for loopback mode.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://p

can: rockchip_canfd: add support for CAN_CTRLMODE_LOOPBACK

Add support for loopback mode.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-19-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: add hardware timestamping support

Add support for hardware based timestamping.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link:

can: rockchip_canfd: add hardware timestamping support

Add support for hardware based timestamping.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-18-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: prepare to use full TX-FIFO depth

So far the TX-FIFO is only used with a depth of 1, although the
hardware offers a depth of 2.

The workaround for the chips that are affected b

can: rockchip_canfd: prepare to use full TX-FIFO depth

So far the TX-FIFO is only used with a depth of 1, although the
hardware offers a depth of 2.

The workaround for the chips that are affected by erratum 6, i.e. EFF
frames may be send as standard frames, is to re-send the EFF frame.
This means the driver cannot queue the next frame for sending, as long
ad the EFF frame has not been successfully send out.

Introduce rkcanfd_get_effective_tx_free() that returns "0" space in
the TX-FIFO if an EFF frame is pending and the actual free space in
the TX-FIFO otherwise. Then replace rkcanfd_get_tx_free() with
rkcanfd_get_effective_tx_free() everywhere.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-16-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: add stats support for errata workarounds

The driver contains workarounds for some of the rk3568v2 errata. Add
ethtool-based statistics ("ethtool -S") to track how often an errat

can: rockchip_canfd: add stats support for errata workarounds

The driver contains workarounds for some of the rk3568v2 errata. Add
ethtool-based statistics ("ethtool -S") to track how often an erratum
workaround was needed.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-15-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: rkcanfd_get_berr_counter_corrected(): work around broken {RX,TX}ERRORCNT register

Tests show that sometimes both CAN bus error counters read 0x0, even
if the controller is in wa

can: rockchip_canfd: rkcanfd_get_berr_counter_corrected(): work around broken {RX,TX}ERRORCNT register

Tests show that sometimes both CAN bus error counters read 0x0, even
if the controller is in warning mode
(RKCANFD_REG_STATE_ERROR_WARNING_STATE in RKCANFD_REG_STATE
set).

To work around this issue, if both error counters read from hardware
are 0x0, use the structure priv->bec, otherwise save the read value in
priv->bec.

In rkcanfd_handle_rx_int_one() decrement the priv->bec.rxerr for
successfully RX'ed CAN frames.

In rkcanfd_handle_tx_done_one() decrement the priv->bec.txerr for
successfully TX'ed CAN frames.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-14-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: implement workaround for erratum 6

The rk3568 CAN-FD errata sheet as of Tue 07 Nov 2023 11:25:31 +08:00
says:

| The CAN controller's transmission of extended frames may
| inter

can: rockchip_canfd: implement workaround for erratum 6

The rk3568 CAN-FD errata sheet as of Tue 07 Nov 2023 11:25:31 +08:00
says:

| The CAN controller's transmission of extended frames may
| intermittently change into standard frames.
|
| When using the CAN controller to send extended frames, if the
| 'tx_req' is configured as 1 and coincides with the internal
| transmission point, the extended frame will be transmitted onto the
| bus in the format of a standard frame.

To work around Erratum 6, the driver is in self-receiving mode (RXSTX)
and all received CAN frames are passed through rkcanfd_rxstx_filter().

Add a check in rkcanfd_rxstx_filter() whether the received frame
corresponds to the current outgoing frame, but the extended CAN ID has
been mangled to a standard ID. In this case re-send the original CAN
frame.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-12-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: add TX PATH

The IP core has a TX event FIFO. In other IP cores, this type of FIFO
usually contains the events that a CAN frame has been successfully
sent. However, the IP core o

can: rockchip_canfd: add TX PATH

The IP core has a TX event FIFO. In other IP cores, this type of FIFO
usually contains the events that a CAN frame has been successfully
sent. However, the IP core on the rk3568v2 the FIFO also holds events
of unsuccessful transmission attempts.

It turned out that the best way to work around this problem is to set
the IP core to self-receive mode (RXSTX), filter out the self-received
frames and insert them into the complete TX path.

Add a pair new functions to check if 2 struct canfd_frame are equal.
The 1st checks if the header of the CAN frames are equal, the 2nd
checks if the data portion are equal:

- rkcanfd_can_frame_header_equal()
- rkcanfd_can_frame_data_equal()

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-11-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: rkcanfd_handle_rx_int_one(): implement workaround for erratum 5: check for empty FIFO

The rk3568 CAN-FD errata sheet as of Tue 07 Nov 2023 11:25:31 +08:00
says:

| Erratum 5: Co

can: rockchip_canfd: rkcanfd_handle_rx_int_one(): implement workaround for erratum 5: check for empty FIFO

The rk3568 CAN-FD errata sheet as of Tue 07 Nov 2023 11:25:31 +08:00
says:

| Erratum 5: Counters related to the TXFIFO and RXFIFO exhibit
| abnormal counting behavior.
|
| Due to a bug in the cross-asynchronous logic of the enable signals
| for rx_fifo_cnt and txe_fifo_frame_cnt counters, the counts of these
| two counters become inaccurate. This issue has resulted in the
| inability to use the TXFIFO and RXFIFO functions.

The errata sheet mentioned above states that only the rk3568v2 is
affected by this erratum, but tests with the rk3568v2 and rk3568v3
show that the RX_FIFO_CNT is sometimes too high. This leads to CAN
frames being read from the FIFO, which is then already empty.

Further tests on the rk3568v2 and rk3568v3 show that in this
situation (i.e. empty FIFO) all elements of the FIFO
header (frameinfo, id, ts) contain the same data.

On the rk3568v2 and rk3568v3, this problem only occurs extremely
rarely with the standard clock of 300 MHz, but almost immediately at
80 MHz.

To workaround this problem, check for empty FIFO with
rkcanfd_fifo_header_empty() in rkcanfd_handle_rx_int_one() and exit
early.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-9-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...

can: rockchip_canfd: add driver for Rockchip CAN-FD controller

Add driver for the Rockchip CAN-FD controller.

The IP core on the rk3568v2 SoC has 12 documented errata. Corrections
for these errata

can: rockchip_canfd: add driver for Rockchip CAN-FD controller

Add driver for the Rockchip CAN-FD controller.

The IP core on the rk3568v2 SoC has 12 documented errata. Corrections
for these errata will be added in the upcoming patches.

Since several workarounds are required for the TX path, only add the
base driver that only implements the RX path.

Although the RX path implements CAN-FD support, it's not activated in
ctrlmode_supported, as the IP core in the rk3568v2 has problems with
receiving or sending certain CAN-FD frames.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-4-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

show more ...