When the TMS is switched on, the node uses PWM (Pulse Width
Modulation) during the data phase instead of the classic NRZ (Non
Return to Zero) encoding.
PWM is configured by three parameters:
- PWMS: Pulse Width Modulation Short phase
- PWML: Pulse Width Modulation Long phase
- PWMO: Pulse Width Modulation Offset time
For each of these parameters, define three IFLA symbols:
- IFLA_CAN_PWM_PWM*_MIN: the minimum allowed value.
- IFLA_CAN_PWM_PWM*_MAX: the maximum allowed value.
- IFLA_CAN_PWM_PWM*: the runtime value.
This results in a total of nine IFLA symbols which are all nested in a
parent IFLA_CAN_XL_PWM symbol.
IFLA_CAN_PWM_PWM*_MIN and IFLA_CAN_PWM_PWM*_MAX define the range of
allowed values and will match the value statically configured by the
device in struct can_pwm_const.
IFLA_CAN_PWM_PWM* match the runtime values stored in struct can_pwm.
Those parameters may only be configured when the tms mode is on. If
the PWMS, PWML and PWMO parameters are provided, check that all the
needed parameters are present using can_validate_pwm(), then check
their value using can_validate_pwm_bittiming(). PWMO defaults to zero
if omitted. Otherwise, if CAN_CTRLMODE_XL_TMS is true but none of the
PWM parameters are provided, calculate them using can_calc_pwm().
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-11-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The Transceiver Mode Switching (TMS) indicates whether the CAN XL
controller shall use the PWM or NRZ encoding during the data phase.
The term "transceiver mode switching" is used in both ISO 11898-1 and
CiA 612-2 (although only the latter one uses the abbreviation TMS). We
adopt the same naming convention here for consistency.
Add the CAN_CTRLMODE_XL_TMS flag to the list of the CAN control modes.
Add can_validate_xl_flags() to check the coherency of the TMS flag.
That function will be reused in upcoming changes to validate the other
CAN XL flags.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-6-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
CAN XL uses bittiming parameters different from Classical CAN and CAN
FD. Thus, all the data bittiming parameters, including TDC, need to be
duplicated for CAN XL.
Add the CAN XL netlink interface for all the features which are common
with CAN FD. Any new CAN XL specific features are added later on.
The first time CAN XL is activated, the MTU is set by default to
CANXL_MAX_MTU. The user may then configure a custom MTU within the
CANXL_MIN_MTU to CANXL_MAX_MTU range, in which case, the custom MTU
value will be kept as long as CAN XL remains active.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-5-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
ISO 11898-1:2024 adds a new restricted operation mode. This mode is
added as a mandatory feature for nodes which support CAN XL and is
retrofitted as optional for legacy nodes (i.e. the ones which only
support Classical CAN and CAN FD).
The restricted operation mode is nearly the same as the listen only
mode: the node can not send data frames or remote frames and can not
send dominant bits if an error occurs. The only exception is that the
node shall still send the acknowledgment bit. A second niche exception
is that the node may still send a data frame containing a time
reference message if the node is a primary time provider, but because
the time provider feature is not yet implemented in the kernel, this
second exception is not relevant to us at the moment.
Add the CAN_CTRLMODE_RESTRICTED control mode flag and update the
can_dev_dropped_skb() helper function accordingly.
Finally, bail out if both CAN_CTRLMODE_LISTENONLY and
CAN_CTRLMODE_RESTRICTED are provided.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-4-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The CAN XL netlink interface will also have data bitrate and TDC
parameters. The current FD parameters do not have a prefix in their
names to differentiate them.
Because the netlink interface is part of the UAPI, it is unfortunately
not feasible to rename the existing symbols to add an FD_ prefix. The
best alternative is to add a comment for each of the symbols to notify
the reader of which parts are CAN FD specific.
While at it, fix a typo: transiver -> transceiver.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-3-e720d28f66fe@kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Currently, the CAN netlink interface provides no easy ways to check
the capabilities of a given controller. The only method from the
command line is to try each CAN_CTRLMODE_* individually to check
whether the netlink interface returns an -EOPNOTSUPP error or not
(alternatively, one may find it easier to directly check the source
code of the driver instead...)
This patch introduces a method for the user to check both the
supported and the static capabilities. The proposed method introduces
a new IFLA nest: IFLA_CAN_CTRLMODE_EXT which extends the current
IFLA_CAN_CTRLMODE. This is done to guaranty a full forward and
backward compatibility between the kernel and the user land
applications.
The IFLA_CAN_CTRLMODE_EXT nest contains one single entry:
IFLA_CAN_CTRLMODE_SUPPORTED. Because this entry is only used in one
direction: kernel to userland, no new struct nla_policy are
introduced.
Below table explains how IFLA_CAN_CTRLMODE_SUPPORTED (hereafter:
"supported") and can_ctrlmode::flags (hereafter: "flags") allow us to
identify both the supported and the static capabilities, when masked
with any of the CAN_CTRLMODE_* bit flags:
supported & flags & Controller capabilities
CAN_CTRLMODE_* CAN_CTRLMODE_*
-----------------------------------------------------------------------
false false Feature not supported (always disabled)
false true Static feature (always enabled)
true false Feature supported but disabled
true true Feature supported and enabled
Link: https://lore.kernel.org/all/20211213160226.56219-5-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add the netlink interface for TDC parameters of struct can_tdc_const
and can_tdc.
Contrary to the can_bittiming(_const) structures for which there is
just a single IFLA_CAN(_DATA)_BITTMING(_CONST) entry per structure,
here, we create a nested entry IFLA_CAN_TDC. Within this nested entry,
additional IFLA_CAN_TDC_TDC* entries are added for each of the TDC
parameters of the newly introduced struct can_tdc_const and struct
can_tdc.
For struct can_tdc_const, these are:
IFLA_CAN_TDC_TDCV_MIN
IFLA_CAN_TDC_TDCV_MAX
IFLA_CAN_TDC_TDCO_MIN
IFLA_CAN_TDC_TDCO_MAX
IFLA_CAN_TDC_TDCF_MIN
IFLA_CAN_TDC_TDCF_MAX
For struct can_tdc, these are:
IFLA_CAN_TDC_TDCV
IFLA_CAN_TDC_TDCO
IFLA_CAN_TDC_TDCF
This is done so that changes can be applied in the future to the
structures without breaking the netlink interface.
The TDC netlink logic works as follow:
* CAN_CTRLMODE_FD is not provided:
- if any TDC parameters are provided: error.
- TDC parameters not provided: TDC parameters unchanged.
* CAN_CTRLMODE_FD is provided and is false:
- TDC is deactivated: both the structure and the
CAN_CTRLMODE_TDC_{AUTO,MANUAL} flags are flushed.
* CAN_CTRLMODE_FD provided and is true:
- CAN_CTRLMODE_TDC_{AUTO,MANUAL} and tdc{v,o,f} not provided: call
can_calc_tdco() to automatically decide whether TDC should be
activated and, if so, set CAN_CTRLMODE_TDC_AUTO and uses the
calculated tdco value.
- CAN_CTRLMODE_TDC_AUTO and tdco provided: set
CAN_CTRLMODE_TDC_AUTO and use the provided tdco value. Here,
tdcv is illegal and tdcf is optional.
- CAN_CTRLMODE_TDC_MANUAL and both of tdcv and tdco provided: set
CAN_CTRLMODE_TDC_MANUAL and use the provided tdcv and tdco
value. Here, tdcf is optional.
- CAN_CTRLMODE_TDC_{AUTO,MANUAL} are mutually exclusive. Whenever
one flag is turned on, the other will automatically be turned
off. Providing both returns an error.
- Combination other than the one listed above are illegal and will
return an error.
N.B. above rules mean that whenever CAN_CTRLMODE_FD is provided, the
previous TDC values will be overwritten. The only option to reuse
previous TDC value is to not provide CAN_CTRLMODE_FD.
All the new parameters are defined as u32. This arbitrary choice is
done to mimic the other bittiming values with are also all of type
u32. An u16 would have been sufficient to hold the TDC values.
This patch completes below series (c.f. [1]):
- commit 289ea9e4ae ("can: add new CAN FD bittiming parameters:
Transmitter Delay Compensation (TDC)")
- commit c25cc79932 ("can: bittiming: add calculation for CAN FD
Transmitter Delay Compensation (TDC)")
[1] https://lore.kernel.org/linux-can/20210224002008.4158-1-mailhol.vincent@wanadoo.fr/T/#t
Link: https://lore.kernel.org/all/20210918095637.20108-5-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
ISO 11898-1 specifies in section 11.3.3 "Transmitter delay
compensation" that "the configuration range for [the] SSP position
shall be at least 0 to 63 minimum time quanta."
Because SSP = TDCV + TDCO, it means that we should allow both TDCV and
TDCO to hold zero value in order to honor SSP's minimum possible
value.
However, current implementation assigned special meaning to TDCV and
TDCO's zero values:
* TDCV = 0 -> TDCV is automatically measured by the transceiver.
* TDCO = 0 -> TDC is off.
In order to allow for those values to really be zero and to maintain
current features, we introduce two new flags:
* CAN_CTRLMODE_TDC_AUTO indicates that the controller support
automatic measurement of TDCV.
* CAN_CTRLMODE_TDC_MANUAL indicates that the controller support
manual configuration of TDCV. N.B.: current implementation failed
to provide an option for the driver to indicate that only manual
mode was supported.
TDC is disabled if both CAN_CTRLMODE_TDC_AUTO and
CAN_CTRLMODE_TDC_MANUAL flags are off, c.f. the helper function
can_tdc_is_enabled() which is also introduced in this patch.
Also, this patch adds three fields: tdcv_min, tdco_min and tdcf_min to
struct can_tdc_const. While we are not convinced that those three
fields could be anything else than zero, we can imagine that some
controllers might specify a lower bound on these. Thus, those minimums
are really added "just in case".
Comments of struct can_tdc and can_tdc_const are updated accordingly.
Finally, the changes are applied to the etas_es58x driver.
Link: https://lore.kernel.org/all/20210918095637.20108-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
ISO 11898-1 Chapter 8.4.2.3 defines a 4 bit data length code (DLC) table which
maps the DLC to the payload length of the CAN frame in bytes:
DLC -> payload length
0 .. 8 -> 0 .. 8
9 .. 15 -> 8
Although the DLC values 8 .. 15 in Classical CAN always result in a payload
length of 8 bytes these DLC values are transparently transmitted on the CAN
bus. As the struct can_frame only provides a 'len' element (formerly 'can_dlc')
which contains the plain payload length ( 0 .. 8 ) of the CAN frame, the raw
DLC is not visible to the application programmer, e.g. for testing use-cases.
To access the raw DLC values 9 .. 15 the len8_dlc element is introduced, which
is only valid when the payload length 'len' is 8 and the DLC is greater than 8.
The len8_dlc element is filled by the CAN interface driver and used for CAN
frame creation by the CAN driver when the CAN_CTRLMODE_CC_LEN8_DLC flag is
supported by the driver and enabled via netlink configuration interface.
Reported-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The "GPL-2.0" license identifier changed to "GPL-2.0-only" in SPDX v3.0.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch fixes some documentation typos in struct can_bittiming_const.
Signed-off-by: Andre Hartmann <aha_1980@gmx.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Various CAN or CAN-FD IP may be able to run at a faster rate than
what the transceiver the CAN node is connected to. This can lead to
unexpected errors. However, CAN transceivers typically have fixed
limitations and provide no means to discover these limitations at
runtime. Therefore, add support for a can-transceiver node that
can be reused by other CAN peripheral drivers to determine for both
CAN and CAN-FD what the max bitrate that can be used. If the user
tries to configure CAN to pass these maximum bitrates it will throw
an error.
Also add support for reading bitrate_max via the netlink interface.
Reviewed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
[nsekhar@ti.com: fix build error with !CONFIG_OF]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.
Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.
GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.
Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some CAN interfaces only support fixed fixed bitrates. This patch adds a
netlink interface to get the list of the CAN interface's fixed bitrates and
data bitrates.
Inside the driver arrays of supported data- bitrate values are defined.
const u32 drvname_bitrate[] = { 20000, 50000, 100000 };
const u32 drvname_data_bitrate[] = { 200000, 500000, 1000000 };
struct drvname_priv *priv;
priv = netdev_priv(dev);
priv->bitrate_const = drvname_bitrate;
priv->bitrate_const_cnt = ARRAY_SIZE(drvname_bitrate);
priv->data_bitrate_const = drvname_data_bitrate;
priv->data_bitrate_const_cnt = ARRAY_SIZE(drvname_data_bitrate);
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch adds a netlink interface to configure the CAN bus termination of
CAN interfaces.
Inside the driver an array of supported termination values is defined:
const u16 drvname_termination[] = { 60, 120, CAN_TERMINATION_DISABLED };
struct drvname_priv *priv;
priv = netdev_priv(dev);
priv->termination_const = drvname_termination;
priv->termination_const_cnt = ARRAY_SIZE(drvname_termination);
priv->termination = CAN_TERMINATION_DISABLED;
And the funtion to set the value has to be defined:
priv->do_set_termination = drvname_set_termination;
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: Ramesh Shanmugasundaram <Ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
During the CAN FD standardization process within the ISO it turned out that
the failure detection capability has to be improved.
The CAN in Automation organization (CiA) defined the already implemented CAN
FD controllers as 'non-ISO' and the upcoming improved CAN FD controllers as
'ISO' compliant. See at http://www.can-cia.com/index.php?id=1937
Finally there will be three types of CAN FD controllers in the future:
1. ISO compliant (fixed)
2. non-ISO compliant (fixed, like the M_CAN IP v3.0.1 in m_can.c)
3. ISO/non-ISO CAN FD controllers (switchable, like the PEAK USB FD)
So the current M_CAN driver for the M_CAN IP v3.0.1 has to expose its non-ISO
implementation by setting the CAN_CTRLMODE_FD_NON_ISO ctrlmode at startup.
As this bit cannot be switched at configuration time CAN_CTRLMODE_FD_NON_ISO
must not be set in ctrlmode_supported of the current M_CAN driver.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Most CAN controllers have a support for ignoring ACK absence. Some of
them refer to this feature as a self test mode (e. g. SJA1000) and some
include it as a part of a loopback mode (e. g. MCP2510).
Setting the introduced flag via netlink should make CAN controller
perform a successful transmission, even if there is no acknowledgement
(dominant ACK bit) received.
Signed-off-by: Nikita Edward Baruzdin <nebaruzdin@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Fixes the corresponing checkpatch.pl warning.
Signed-off-by: Nikita Edward Baruzdin <nebaruzdin@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Armin pointed me to the fact that the identifier which is used to ensure the
unique include processing in lunux/include/uapi/linux/can.h is CAN_H.
This clashed with his own source as includes from libraries and APIs should
use an underscore '_' at the identifier start.
This patch fixes the protection identifiers in all CAN relavant includes.
Reported-by: Armin Burchardt <armin@uni-bremen.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The configuration for CAN FD depends on CAN_CTRLMODE_FD enabled in the driver
specific ctrlmode_supported capabilities.
The configuration can be done either with the 'fd { on | off }' option in the
'ip' tool from iproute2 or by setting the CAN netdevice MTU to CAN_MTU (16) or
to CANFD_MTU (72).
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
As CAN FD offers a second bitrate for the data section of the CAN frame the
infrastructure for storing and configuring this second bitrate is introduced.
Improved the readability of the if-statement by inserting some newlines.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This file is copied to the source code of user space applications (in
this case can-utils) and so it makes sense to mention explicitly their
copyright.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Vincent Mailhol