Merge patch series "can: netlink: add CAN XL support"

Marc Kleine-Budde <mkl@pengutronix.de> says:

Similarly to how CAN FD reuses the bittiming logic of Classical CAN, CAN XL
also reuses the entirety of CAN FD features, and, on top of that, adds new
features which are specific to CAN XL.

A so-called 'mixed-mode' is intended to have (XL-tolerant) CAN FD nodes and
CAN XL nodes on one CAN segment, where the FD-controllers can talk CC/FD
and the XL-controllers can talk CC/FD/XL. This mixed-mode utilizes the
known error-signalling (ES) for sending CC/FD/XL frames. For CAN FD and CAN
XL the tranceiver delay compensation (TDC) is supported to use common CAN
and CAN-SIG transceivers.

The CANXL-only mode disables the error-signalling in the CAN XL controller.
This mode does not allow CC/FD frames to be sent but additionally offers a
CAN XL transceiver mode switching (TMS) to send CAN XL frames with up to
20Mbit/s data rate. The TMS utilizes a PWM configuration which is added to
the netlink interface.

Configured with CAN_CTRLMODE_FD and CAN_CTRLMODE_XL this leads to:

FD=0 XL=0 CC-only mode         (ES=1)
FD=1 XL=0 FD/CC mixed-mode     (ES=1)
FD=1 XL=1 XL/FD/CC mixed-mode  (ES=1)
FD=0 XL=1 XL-only mode         (ES=0, TMS optional)

Patch #1 print defined ctrlmode strings capitalized to increase the
readability and to be in line with the 'ip' tool (iproute2).

Patch #2 is a small clean-up which makes can_calc_bittiming() use
NL_SET_ERR_MSG() instead of netdev_err().

Patch #3 adds a check in can_dev_dropped_skb() to drop CAN FD frames
when CAN FD is turned off.

Patch #4 adds CAN_CTRLMODE_RESTRICTED. Note that contrary to the other
CAN_CTRL_MODE_XL_* that are introduced in the later patches, this control
mode is not specific to CAN XL. The nuance is that because this restricted
mode was only added in ISO 11898-1:2024, it is made mandatory for CAN XL
devices but optional for other protocols. This is why this patch is added
as a preparation before introducing the core CAN XL logic.

Patch #5 adds all the CAN XL features which are inherited from CAN FD: the
nominal bittiming, the data bittiming and the TDC.

Patch #6 add a new CAN_CTRLMODE_XL_TMS control mode which is specific to
CAN XL to enable the transceiver mode switching (TMS) in XL-only mode.

Patch #7 adds a check in can_dev_dropped_skb() to drop CAN CC/FD frames
when the CAN XL controller is in CAN XL-only mode. The introduced
can_dev_in_xl_only_mode() function also determines the error-signalling
configuration for the CAN XL controllers.

Patch #8 to #11 add the PWM logic for the CAN XL TMS mode.

Patch #12 to #14 add different default sample-points for standard CAN and
CAN SIG transceivers (with TDC) and CAN XL transceivers using PWM in the
CAN XL TMS mode.

Patch #15 add a dummy_can driver for netlink testing and debugging.

Patch #16 check CAN frame type (CC/FD/XL) when writing those frames to the
CAN_RAW socket and reject them if it's not supported by the CAN interface.

Patch #17 increase the resolution when printing the bitrate error and
round-up the value to 0.01% in the case the resolution would still provide
values which would lead to 0.00%.

Link: https://patch.msgid.link/20251126-canxl-v8-0-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 34 insertions, 0 deletions

diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index ef62f56eaaef..c30d16746159 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -5,6 +5,7 @@
  * Definitions for the CAN netlink interface
  *
  * Copyright (c) 2009 Wolfgang Grandegger <wg@grandegger.com>
+ * Copyright (c) 2021-2025 Vincent Mailhol <mailhol@kernel.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the version 2 of the GNU General Public License
@@ -103,6 +104,11 @@ struct can_ctrlmode {
 #define CAN_CTRLMODE_CC_LEN8_DLC	0x100	/* Classic CAN DLC option */
 #define CAN_CTRLMODE_TDC_AUTO		0x200	/* FD transceiver automatically calculates TDCV */
 #define CAN_CTRLMODE_TDC_MANUAL		0x400	/* FD TDCV is manually set up by user */
+#define CAN_CTRLMODE_RESTRICTED		0x800	/* Restricted operation mode */
+#define CAN_CTRLMODE_XL			0x1000	/* CAN XL mode */
+#define CAN_CTRLMODE_XL_TDC_AUTO	0x2000	/* XL transceiver automatically calculates TDCV */
+#define CAN_CTRLMODE_XL_TDC_MANUAL	0x4000	/* XL TDCV is manually set up by user */
+#define CAN_CTRLMODE_XL_TMS		0x8000	/* Transceiver Mode Switching */
 
 /*
  * CAN device statistics
@@ -138,6 +144,11 @@ enum {
 	IFLA_CAN_BITRATE_MAX,
 	IFLA_CAN_TDC, /* FD */
 	IFLA_CAN_CTRLMODE_EXT,
+	IFLA_CAN_XL_DATA_BITTIMING,
+	IFLA_CAN_XL_DATA_BITTIMING_CONST,
+	IFLA_CAN_XL_DATA_BITRATE_CONST,
+	IFLA_CAN_XL_TDC,
+	IFLA_CAN_XL_PWM,
 
 	/* add new constants above here */
 	__IFLA_CAN_MAX,
@@ -179,6 +190,29 @@ enum {
 	IFLA_CAN_CTRLMODE_MAX = __IFLA_CAN_CTRLMODE - 1
 };
 
+/*
+ * CAN FD/XL Pulse-Width Modulation (PWM)
+ *
+ * Please refer to struct can_pwm_const and can_pwm in
+ * include/linux/can/bittiming.h for further details.
+ */
+enum {
+	IFLA_CAN_PWM_UNSPEC,
+	IFLA_CAN_PWM_PWMS_MIN,	/* u32 */
+	IFLA_CAN_PWM_PWMS_MAX,	/* u32 */
+	IFLA_CAN_PWM_PWML_MIN,	/* u32 */
+	IFLA_CAN_PWM_PWML_MAX,	/* u32 */
+	IFLA_CAN_PWM_PWMO_MIN,	/* u32 */
+	IFLA_CAN_PWM_PWMO_MAX,	/* u32 */
+	IFLA_CAN_PWM_PWMS,	/* u32 */
+	IFLA_CAN_PWM_PWML,	/* u32 */
+	IFLA_CAN_PWM_PWMO,	/* u32 */
+
+	/* add new constants above here */
+	__IFLA_CAN_PWM,
+	IFLA_CAN_PWM_MAX = __IFLA_CAN_PWM - 1
+};
+
 /* u16 termination range: 1..65535 Ohms */
 #define CAN_TERMINATION_DISABLED 0