can: gs_usb: gs_cmd_reset(): use cpu_to_le32() to assign mode

The structure gs_device_mode dm::mode is a __le32, use cpu_to_le32()
to assign GS_CAN_MODE_RESET.

As GS_CAN_MODE_RESET is 0x0, this is basically a no-op.

Link: https://lore.kernel.org/all/20240304074540.3584842-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: convert to NAPI/rx-offload to avoid OoO reception

The driver used to pass received CAN frames/skbs to the network stack
with netif_rx(). In netif_rx() the skbs are queued to the local CPU.
If IRQs are handled in round robin, OoO packets may occur.

To avoid out-of-order reception convert the driver from netif_rx() to
NAPI.

For USB devices with timestamping support use the rx-offload helper
can_rx_offload_queue_timestamp() for the RX, and
can_rx_offload_get_echo_skb_queue_timestamp() for the TX path. Devices
without timestamping support use can_rx_offload_queue_tail() for RX,
and can_rx_offload_get_echo_skb_queue_tail() for the TX path.

Link: https://lore.kernel.org/all/559D628C.5020100@hartkopp.net
Link: https://github.com/candle-usb/candleLight_fw/issues/166
Link: https://lore.kernel.org/all/20230718-gs_usb-rx-offload-v2-3-716e542d14d5@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_disconnect(): remove not needed usb_kill_anchored_urbs()

In gs_usb_disconnect(), all channels are destroyed first, then all
anchored RX URBs (parent->rx_submitted) are disposed with
usb_kill_anchored_urbs().

The call to usb_kill_anchored_urbs() is not needed, as
gs_destroy_candev() of the last active channel already disposes the RX
URBS.

Remove not needed call to usb_kill_anchored_urbs() from
gs_usb_disconnect().

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-11-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_destroy_candev(): remove not needed usb_kill_anchored_urbs()

In gs_destroy_candev(), the netdev is unregistered first, then all
anchored TX URBs (dev->tx_submitted) are disposed with
usb_kill_anchored_urbs().

The call to usb_kill_anchored_urbs() is not needed, as
unregister_candev() calls gs_can_close(), which already disposes the
TX URBS.

Remove not needed call to usb_kill_anchored_urbs() from
gs_destroy_candev().

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-10-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_close(): don't complain about failed device reset during ndo_stop

When the USB device is unplugged, gs_can_close() (which implements the
struct net_device_ops::ndo_stop callback) is called. In this function
an attempt is made to shut down the USB device with a USB control
message. For disconnected devices this will fail and a warning message
is printed.

Silence the driver by removing the printout of the error message if
the reset command fails.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-9-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_start_xmit(), gs_can_open(): clean up printouts in error path

Remove unnecessary "out of memory" message from the error path of
gs_can_start_xmit() and gs_can_open().

Convert the printout in case of a failing usb_submit_urb() in
gs_can_open() from numbers to human readable error codes.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-8-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_receive_bulk_callback(): count RX overflow errors also in case of OOM

In case of an RX overflow error from the CAN controller and an OOM
where no skb can be allocated, the error counters are not incremented.

Fix this by first incrementing the error counters and then allocate
the skb.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-7-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_receive_bulk_callback(): make use of stats

Make use the previously assigned variable stats instead of using
netdev->stats.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-6-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_receive_bulk_callback(): make use of netdev

Make use the previously assigned variable netdev instead of using
dev->netdev.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-5-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: uniformly use "parent" as variable name for struct gs_usb

To ease readability and maintainability uniformly use the variable
name "parent" for the struct gs_usb in the gs_usb driver.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-4-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_set_timestamp(): remove return statements form void function

Remove the return statements from void gs_usb_set_timestamp()
function, as it's not generally useful.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-3-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_probe(): align block comment

Indent block comment so that it aligns the * on each line.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-2-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: remove leading space from goto labels

Remove leading spaces from goto labels in accordance with the kernel
encoding style.

Link: https://lore.kernel.org/all/20230718-gs_usb-cleanups-v1-1-c3b9154ec605@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_close(): add missing set of CAN state to CAN_STATE_STOPPED

After an initial link up the CAN device is in ERROR-ACTIVE mode. Due
to a missing CAN_STATE_STOPPED in gs_can_close() it doesn't change to
STOPPED after a link down:

| ip link set dev can0 up
| ip link set dev can0 down
| ip --details link show can0
| 13: can0: <NOARP,ECHO> mtu 16 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 10
| link/can promiscuity 0 allmulti 0 minmtu 0 maxmtu 0
| can state ERROR-ACTIVE restart-ms 1000

Add missing assignment of CAN_STATE_STOPPED in gs_can_close().

Cc: stable@vger.kernel.org
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20230718-gs_usb-fix-can-state-v1-1-f19738ae2c23@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix time stamp counter initialization

If the gs_usb device driver is unloaded (or unbound) before the
interface is shut down, the USB stack first calls the struct
usb_driver::disconnect and then the struct net_device_ops::ndo_stop
callback.

In gs_usb_disconnect() all pending bulk URBs are killed, i.e. no more
RX'ed CAN frames are send from the USB device to the host. Later in
gs_can_close() a reset control message is send to each CAN channel to
remove the controller from the CAN bus. In this race window the USB
device can still receive CAN frames from the bus and internally queue
them to be send to the host.

At least in the current version of the candlelight firmware, the queue
of received CAN frames is not emptied during the reset command. After
loading (or binding) the gs_usb driver, new URBs are submitted during
the struct net_device_ops::ndo_open callback and the candlelight
firmware starts sending its already queued CAN frames to the host.

However, this scenario was not considered when implementing the
hardware timestamp function. The cycle counter/time counter
infrastructure is set up (gs_usb_timestamp_init()) after the USBs are
submitted, resulting in a NULL pointer dereference if
timecounter_cyc2time() (via the call chain:
gs_usb_receive_bulk_callback() -> gs_usb_set_timestamp() ->
gs_usb_skb_set_timestamp()) is called too early.

Move the gs_usb_timestamp_init() function before the URBs are
submitted to fix this problem.

For a comprehensive solution, we need to consider gs_usb devices with
more than 1 channel. The cycle counter/time counter infrastructure is
setup per channel, but the RX URBs are per device. Once gs_can_open()
of _a_ channel has been called, and URBs have been submitted, the
gs_usb_receive_bulk_callback() can be called for _all_ available
channels, even for channels that are not running, yet. As cycle
counter/time counter has not set up, this will again lead to a NULL
pointer dereference.

Convert the cycle counter/time counter from a "per channel" to a "per
device" functionality. Also set it up, before submitting any URBs to
the device.

Further in gs_usb_receive_bulk_callback(), don't process any URBs for
not started CAN channels, only resubmit the URB.

Fixes: 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support")
Closes: https://github.com/candle-usb/candleLight_fw/issues/137#issuecomment-1623532076
Cc: stable@vger.kernel.org
Cc: John Whittington <git@jbrengineering.co.uk>
Link: https://lore.kernel.org/all/20230716-gs_usb-fix-time-stamp-counter-v1-2-9017cefcd9d5@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): improve error handling

The gs_usb driver handles USB devices with more than 1 CAN channel.
The RX path for all channels share the same bulk endpoint (the
transmitted bulk data encodes the channel number). These per-device
resources are allocated and submitted by the first opened channel.

During this allocation, the resources are either released immediately
in case of a failure or the URBs are anchored. All anchored URBs are
finally killed with gs_usb_disconnect().

Currently, gs_can_open() returns with an error if the allocation of a
URB or a buffer fails. However, if usb_submit_urb() fails, the driver
continues with the URBs submitted so far, even if no URBs were
successfully submitted.

Treat every error as fatal and free all allocated resources
immediately.

Switch to goto-style error handling, to prepare the driver for more
per-device resource allocation.

Cc: stable@vger.kernel.org
Cc: John Whittington <git@jbrengineering.co.uk>
Link: https://lore.kernel.org/all/20230716-gs_usb-fix-time-stamp-counter-v1-1-9017cefcd9d5@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: remove gs_can::iface

The iface field of struct gs_can is only used to retrieve the
usb_device which is already available in gs_can::udev.

Replace each occurrence of interface_to_usbdev(dev->iface) with
dev->udev. This done, remove gs_can::iface.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221208081142.16936-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add support for reading error counters

Add support for reading the device state and CAN error counters, using
the GS_USB_BREQ_GET_STATE control message, if supported by the device,
indicated by the GS_CAN_FEATURE_GET_STATE feature flag.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Link: https://lore.kernel.org/all/20221019221016.1659260-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: document GS_CAN_FEATURE_GET_STATE

Document the new feature ("GS_CAN_FEATURE_GET_STATE") that indicates
that the state of the CAN controller can be queried with the new
GS_USB_BREQ_GET_STATE control message.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Link: https://lore.kernel.org/all/20221019221016.1659260-7-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add ability to enable / disable berr reporting

The open source firmware candleLight report bus errors
unconditionally. This adds support to enable / disable bus error
reporting with the standard netlink property.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Link: https://lore.kernel.org/all/20221019221016.1659260-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: document GS_CAN_FEATURE_BERR_REPORTING

Document the new feature ("GS_CAN_FEATURE_BERR_REPORTING") that
indicates that the bus error reporting in the CAN controller can
switched on and off with the GS_CAN_MODE_BERR_REPORTING mode bit in
the GS_USB_BREQ_MODE control message.

Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Link: https://lore.kernel.org/all/20221019221016.1659260-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): merge setting of timestamp flags and init

Merge the bodies of 2 consecutive "if (dev->feature &
GS_CAN_FEATURE_HW_TIMESTAMP)" statements.

Link: https://lore.kernel.org/all/20221019221016.1659260-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): sort checks for ctrlmode

Sort the checks for dev->can.ctrlmode by values of CAN_CTRLMODE_*, so
that it's clear where to add new checks.

While there, remove the comment that the Atmel UC3C hardware doesn't
support One Shot Mode. The One Shot mode is only available and to be
activated by the user, if the device specifies the feature bit
GS_CAN_FEATURE_ONE_SHOT.

Link: https://lore.kernel.org/all/20221019221016.1659260-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): allow loopback and listen only at the same time

There's no reason why loopback and listen only should not be allowed
at the same time. Replace the "else if" by "if" to reflect this in the
code.

Link: https://lore.kernel.org/all/20221019221016.1659260-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_make_candev(): set netdev->dev_id

The gs_usb driver supports USB devices with more than 1 CAN channel.
Set the "netdev->dev_id" to distinguish between channels in user
space.

Link: https://lore.kernel.org/all/20221007075418.213403-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: dev: fix skb drop check

In commit a6d190f8c767 ("can: skb: drop tx skb if in listen only
mode") the priv->ctrlmode element is read even on virtual CAN
interfaces that do not create the struct can_priv at startup. This
out-of-bounds read may lead to CAN frame drops for virtual CAN
interfaces like vcan and vxcan.

This patch mainly reverts the original commit and adds a new helper
for CAN interface drivers that provide the required information in
struct can_priv.

Fixes: a6d190f8c767 ("can: skb: drop tx skb if in listen only mode")
Reported-by: Dariusz Stojaczyk <Dariusz.Stojaczyk@opensynergy.com>
Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Cc: Max Staudt <max@enpas.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221102095431.36831-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org # 6.0.x
[mkl: patch pch_can, too]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: remove dma allocations

DMA allocated buffers are a precious resource. If there is no need for
DMA allocations, then it might be worth to use non-dma allocated
buffers.

After testing the gs_usb driver with and without DMA allocation, there
does not seem to be a significant change in latency or CPU utilization
either way. Therefore, DMA allocation is not necessary and removed.

Internal buffers used within urbs were managed and freed manually.
These buffers are no longer needed to be managed by the driver. The
URB_FREE_BUFFER flag, allows for the buffers in question to be
automatically freed.

Co-developed-by: Rhett Aultman <rhett.aultman@samsara.com>
Signed-off-by: Rhett Aultman <rhett.aultman@samsara.com>
Signed-off-by: Vasanth Sadhasivan <vasanth.sadhasivan@samsara.com>
Link: https://lore.kernel.org/all/20220920154724.861093-2-rhett.aultman@samsara.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add switchable termination support

The candleLight community is working on switchable termination support
for the candleLight firmware. As the the Linux CAN framework supports
switchable termination add this feature to the gs_usb driver.

Devices supporting the feature should set the
GS_CAN_FEATURE_TERMINATION and implement the
GS_USB_BREQ_SET_TERMINATION and GS_USB_BREQ_GET_TERMINATION control
messages.

For now the driver assumes for activated termination the standard
termination value of 120Ω.

Link: https://lore.kernel.org/all/20220923074114.662045-1-mkl@pengutronix.de
Link: https://github.com/candle-usb/candleLight_fw/issues/92
Link: https://github.com/candle-usb/candleLight_fw/pull/109
Link: https://github.com/candle-usb/candleLight_fw/pull/108
Cc: Daniel Trevitz <daniel.trevitz@wika.com>
Cc: Ryan Edwards <ryan.edwards@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_make_candev(): clean up error handling

Introduce a label to free the allocated candev in case of an error and
make use of if. Fix a memory leak if the extended bit timing cannot be
read. Extend the error messages to print the number of the failing
channel and the symbolic error name.

Link: https://lore.kernel.org/all/20220921193902.575416-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: convert from usb_control_msg() to usb_control_msg_{send,recv}()

Convert the driver to use usb_control_msg_{send,recv}() instead of
usb_control_msg(). These functions allow the data to be placed on the
stack. This makes the driver a lot easier as we don't have to deal
with dynamically allocated memory.

Link: https://lore.kernel.org/all/20220921193902.575416-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_cmd_reset(): rename variable holding struct gs_can pointer to dev

Most of the driver uses the variable "dev" to point to the struct
gs_can. Use the same name in gs_cmd_reset(), too. Rename gsdev to dev.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20220921193902.575416-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): initialize time counter before starting device

On busy networks the CAN controller might receive CAN frames directly
after starting it but before the timecounter is setup. This will lead
to NULL pointer deref while converting the converting the CAN frame's
timestamp with the timecounter.

Close the race window by setting up the timecounter before starting
the CAN controller.

Fixes: 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support")
Link: https://lore.kernel.org/all/20220921081329.385509-1-mkl@pengutronix.de
Cc: John Whittington <git@jbrengineering.co.uk
Tested-by: John Whittington <git@jbrengineering.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add missing lock to protect struct timecounter::cycle_last

The struct timecounter::cycle_last is a 64 bit variable, read by
timecounter_cyc2time(), and written by timecounter_read(). On 32 bit
architectures this is not atomic.

Add a spinlock to protect access to struct timecounter::cycle_last. In
the gs_usb_timestamp_read() callback the lock is dropped to execute a
sleeping synchronous USB transfer. This is safe, as the variable we
want to protect is accessed during this call.

Fixes: 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support")
Link: https://lore.kernel.org/all/20220920100416.959226-3-mkl@pengutronix.de
Cc: John Whittington <git@jbrengineering.co.uk>
Tested-by: John Whittington <git@jbrengineering.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_get_timestamp(): fix endpoint parameter for usb_control_msg_recv()

The 2nd argument of usb_control_msg_recv() is the "endpoint",
usb_control_msg_recv() will internally convert the endpoint into a
pipe with usb_rcvctrlpipe().

In gs_usb_get_timestamp() not the endpoint "0" is passed, but the
pipe. This worked by accident as endpoint is a __u8 and the lowest 8
bits of the pipe are 0. Fix this copy/paste error by using the correct
endpoint of "0".

Fixes: 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support")
Link: https://lore.kernel.org/all/20220920100416.959226-2-mkl@pengutronix.de
Cc: John Whittington <git@jbrengineering.co.uk>
Tested-by: John Whittington <git@jbrengineering.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add RX and TX hardware timestamp support

Add support for hardware timestamps, if the firmware includes it as a
feature via the GS_CAN_FEATURE_HW_TIMESTAMP flag. Check for this
feature during probe, extend the RX expected length if it is and
enable it during open.

The struct classic_can_ts and struct canfd_ts are extended to include
the µs timestamp following data as defined in the firmware. The
timestamp is then captured and set using skb_hwtstamps() on each RX
and TX.

The frame µs timestamp is provided from a 32 bit 1 MHz timer which
rolls over every 4294 seconds, so a cyclecounter, timecounter, and
delayed worker are used to convert the timer into a proper ns
timestamp - same implementation as commit efd8d98dfb900 ("can:
mcp251xfd: add HW timestamp infrastructure").

Hardware timestamps are added to capabilities as commit
b1f6b93e678f ("can: mcp251xfd: advertise timestamping capabilities and
add ioctl support").

Signed-off-by: John Whittington <git@jbrengineering.co.uk>
Link: https://github.com/candle-usb/candleLight_fw/issues/100
Link: https://lore.kernel.org/all/20220827221548.3291393-3-mkl@pengutronix.de
Co-developed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: use common spelling of GS_USB in macros

There are a few macros in the driver which use GSUSB in the name of
the macro, while the majority uses GS_USB. Convert all macros to
GS_USB.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Fixes: b00ca070e022 ("can: gs_usb: activate quirks for CANtact Pro unconditionally")
Link: https://lore.kernel.org/all/20220827221548.3291393-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_set_phys_id(): return with error if identify is not supported

Until commit 409c188c57cd ("can: tree-wide: advertise software
timestamping capabilities") the ethtool_ops was only assigned for
devices which support the GS_CAN_FEATURE_IDENTIFY feature. That commit
assigns ethtool_ops unconditionally.

This results on controllers without GS_CAN_FEATURE_IDENTIFY support
for the following ethtool error:

| $ ethtool -p can0 1
| Cannot identify NIC: Broken pipe

Restore the correct error value by checking for
GS_CAN_FEATURE_IDENTIFY in the gs_usb_set_phys_id() function.

| $ ethtool -p can0 1
| Cannot identify NIC: Operation not supported

While there use the variable "netdev" for the "struct net_device"
pointer and "dev" for the "struct gs_can" pointer as in the rest of
the driver.

Fixes: 409c188c57cd ("can: tree-wide: advertise software timestamping capabilities")
Link: http://lore.kernel.org/all/20220818143853.2671854-1-mkl@pengutronix.de
Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): fix race dev->can.state condition

The dev->can.state is set to CAN_STATE_ERROR_ACTIVE, after the device
has been started. On busy networks the CAN controller might receive
CAN frame between and go into an error state before the dev->can.state
is assigned.

Assign dev->can.state before starting the controller to close the race
window.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20220920195216.232481-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: tree-wide: advertise software timestamping capabilities

Currently, some CAN drivers support hardware timestamping, some do
not. But userland has no method to query which features are supported
(aside maybe of getting RX messages and observe whether or not
hardware timestamps stay at zero).

The canonical way for a network driver to advertised what kind of
timestamping it supports is to implement ethtool_ops::get_ts_info().

This patch only targets the CAN drivers which *do not* support
hardware timestamping. For each of those CAN drivers, implement the
get_ts_info() using the generic ethtool_op_get_ts_info().

This way, userland can do:

| $ ethtool --show-time-stamping canX

to confirm the device timestamping capacities.

N.B. the drivers which support hardware timestamping will be migrated
in separate patches.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-6-mailhol.vincent@wanadoo.fr
[mkl: mscan: add missing mscan_ethtool_ops]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_ubs: use KBUILD_MODNAME instead of hard coded names

The driver uses the string "gs_usb" to populate usb_driver::name,
can_bittiming_const::name and
can_data_bittiming_const::name. KBUILD_MODNAME evaluates to
"gs_ubs". Use KBUILD_MODNAME and get rid on the hardcoded string
names.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220726082707.58758-7-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_open/close(): fix memory leak

The gs_usb driver appears to suffer from a malady common to many USB
CAN adapter drivers in that it performs usb_alloc_coherent() to
allocate a number of USB request blocks (URBs) for RX, and then later
relies on usb_kill_anchored_urbs() to free them, but this doesn't
actually free them. As a result, this may be leaking DMA memory that's
been used by the driver.

This commit is an adaptation of the techniques found in the esd_usb2
driver where a similar design pattern led to a memory leak. It
explicitly frees the RX URBs and their DMA memory via a call to
usb_free_coherent(). Since the RX URBs were allocated in the
gs_can_open(), we remove them in gs_can_close() rather than in the
disconnect function as was done in esd_usb2.

For more information, see the 928150fad41b ("can: esd_usb2: fix memory
leak").

Link: https://lore.kernel.org/all/alpine.DEB.2.22.394.2206031547001.1630869@thelappy
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: stable@vger.kernel.org
Signed-off-by: Rhett Aultman <rhett.aultman@samsara.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_make_candev(): fix memory leak for devices with extended bit timing configuration

Some CAN-FD capable devices offer extended bit timing information for
the data bit timing. The information must be read with an USB control
message. The memory for this message is allocated but not free()ed (in
the non error case). This patch adds the missing free.

Fixes: 6679f4c5e5a6 ("can: gs_usb: add extended bt_const feature")
Link: https://lore.kernel.org/all/20220329193450.659726-1-mkl@pengutronix.de
Reported-by: syzbot+4d0ae90a195b269f102d@syzkaller.appspotmail.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add VID/PID for ABE CAN Debugger devices

Add support for ABE CAN Debugger devices using the gs_usb driver.

Link: https://lore.kernel.org/all/20220309124132.291861-22-mkl@pengutronix.de
Signed-off-by: Ben Evans <benny.j.evans92@gmail.com>
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add VID/PID for CES CANext FD devices

Add support for Christ Electronic Systems GmbH
CANext FD devices using the gs_usb driver.

Link: https://lore.kernel.org/all/20220309124132.291861-21-mkl@pengutronix.de
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add extended bt_const feature

For example CANext FD needs to distinguish between bittiming constants
valid for arbitration phase and data phase to reach maximum
performance at higher speeds.

Link: https://lore.kernel.org/all/20220309124132.291861-20-mkl@pengutronix.de
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Christoph Möhring <cmoehring@christ-es.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: activate quirks for CANtact Pro unconditionally

The CANtact Pro from LinkLayer Labs is based on the LPC54616 µC, which
is affected by the NXP LPC USB transfer erratum. However, the current
firmware (version 2) doesn't set the
GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit.

This patch sets the feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to
workaround this issue.

For the GS_USB_BREQ_DATA_BITTIMING USB control message the CANtact Pro
firmware uses a request value, which is already used by the
candleLight firmware for a different purpose
(GS_USB_BREQ_GET_USER_ID).

This patch set the feature GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to
workaround this issue.

Link: https://lore.kernel.org/all/20220309124132.291861-19-mkl@pengutronix.de
Cc: Ryan Edwards <ryan.edwards@gmail.com>
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Christoph Möhring <cmoehring@christ-es.de>
[mkl: improve check for CANtact Pro and add GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO quirk]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add quirk for CANtact Pro overlapping GS_USB_BREQ value

For the GS_USB_BREQ_DATA_BITTIMING USB control message the CANtact Pro
firmware uses a request value, which is already used by the
candleLight firmware for a different
purpose (GS_USB_BREQ_GET_USER_ID).

This patch adds a quirk to use the CANtact Pro's value for the
GS_USB_BREQ_DATA_BITTIMING USB control message instead of the official
one.

Link: https://lore.kernel.org/all/20220309124132.291861-18-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add usb quirk for NXP LPC546xx controllers

Introduce a workaround for a NXP chip errata on LPC546xx
controllers (Errata sheet LPC546xx / USB.15).

According to the document corruption can occur when the following
conditions are met:
* A TX (IN) transfer happens after a RX (OUT) transfer.
* The RX (OUT) transfer length is 4 + N * 16 (N >= 0) bytes.

Even though the struct gs_host_frame has a size of 76 bytes for a FD
frame, which does not apply to the above rule, corruption could be
seen.

Adding a dummy byte to break the second condition also on transfer
lengths with 4 + N * 8 bytes reliably circumvents USB transfer data
corruption.

The firmware can now request this quirk by setting
GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX.

Link: https://lore.kernel.org/all/20220309124132.291861-17-mkl@pengutronix.de
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Christoph Möhring <cmoehring@christ-es.de>
Signed-off-by: Alexander Schartner <aschartner@christ-es.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add CAN-FD support

CANtact Pro from Linklayer is the first gs_usb compatible device
supporting CAN-FD with a different HW and re-written candlelight FW.

Support for CAN-FD is indicated by the device setting the
GS_CAN_FEATURE_FD flag. CAN-FD support is requested by the driver with
the GS_CAN_MODE_FD flag. The CAN-FD specific data bit timing
parameters are set with the GS_USB_BREQ_DATA_BITTIMING control
message.

This patch is based on the Eric Evenchick's gs_usb_fd driver (which
itself is a fork of gs_usb). The gs_usb_fd code base was reintegrated
into the gs_usb driver, and reworked to not break the existing
classical-CAN only hardware.

Link: https://lore.kernel.org/all/20220309124132.291861-16-mkl@pengutronix.de
Link: https://github.com/linklayer/gs_usb_fd/issues/2
Co-developed-by: Eric Evenchick <eric@evenchick.com>
Signed-off-by: Eric Evenchick <eric@evenchick.com>
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: use union and FLEX_ARRAY for data in struct gs_host_frame

Modify struct gs_host_frame to make use of a union and
DECLARE_FLEX_ARRAY to be able to store different data (lengths), which
will be added in later commits.

Store the gs_host_frame length in TX direction (host -> device) in
struct gs_can::hf_size_tx and RX direction (device -> host) in struct
gs_usb::hf_size_rx so it must be calculated only once.

Link: https://lore.kernel.org/all/20220309124132.291861-15-mkl@pengutronix.de
Signed-off-by: Peter Fink <pfink@christ-es.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: support up to 3 channels per device

Some STM32G3 chips support up to 3 CAN-FD channels, increase number of
supported channels in this driver to 3 accordingly.

Link: https://lore.kernel.org/all/20220309124132.291861-14-mkl@pengutronix.de
Suggested-by: Ryan Edwards <ryan.edwards@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_probe(): introduce udev and make use of it

Introduce the variable udev in the gs_usb_probe() function to hold a
pointer to the struct usb_device. This avoids recalculating the value
several times in this function.

Link: https://lore.kernel.org/all/20220309124132.291861-13-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: document the PAD_PKTS_TO_MAX_PKT_SIZE feature

The widely used open source firmware candleLight supports padding the
USB packets to max packet size to improve performance on Windows
systems.

This patch documents the bit.

Link: https://lore.kernel.org/all/20220309124132.291861-12-mkl@pengutronix.de
Link: https://github.com/candle-usb/candleLight_fw/pull/7
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: document the USER_ID feature

The widely used open source firmware candleLight has optional support
for reading/writing of an user defined value into the device's flash.

This is indicated by the GS_CAN_FEATURE_USER_ID feature. The
corresponding request are GS_USB_BREQ_GET_USER_ID and
GS_USB_BREQ_SET_USER_ID.

This patch documents these values.

Link: https://lore.kernel.org/all/20220309124132.291861-11-mkl@pengutronix.de
Link: https://github.com/candle-usb/candleLight_fw/commit/1453d70dc9a9d98ac254893ba5114b8e826e0e39
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: update GS_CAN_FEATURE_IDENTIFY documentation

In the binary interface a feature bit might have a corresponding mode
bit (of the same value).

The GS_CAN_FEATURE_IDENTIFY feature doesn't come with a mode. Document
this, to avoid gaps when adding more features/modes later.

Link: https://lore.kernel.org/all/20220309124132.291861-10-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add HW timestamp mode bit

Newer versions of the widely used open source firmware candleLight
support hardware timestamps. The support is activated by setting the
GS_CAN_MODE_HW_TIMESTAMP in the GS_USB_BREQ_MODE request.

Although timestamp support is not yet supported by this driver, add
the missing bit for documentation purpose.

Link: https://lore.kernel.org/all/20220309124132.291861-9-mkl@pengutronix.de
Link: https://github.com/candle-usb/candleLight_fw/commit/44431f4a4354a878fbd15b273bf04fce1dcdff7e
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_make_candev(): call SET_NETDEV_DEV() after handling all bt_const->feature

This patch moves the call to SET_NETDEV_DEV() after all handling
(including cleanup) of the bt_const->feature is done. This looks more
consistent.

Link: https://lore.kernel.org/all/20220309124132.291861-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: rewrap usb_control_msg() and usb_fill_bulk_urb()

This patch rewraps the arguments of usb_control_msg() and
usb_fill_bulk_urb() to make full use of the standard line length of 80
characters.

Link: https://lore.kernel.org/all/20220309124132.291861-7-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: rewrap error messages

This patch rewraps the arguments of netdev_err() to make full use of
the standard line length of 80 characters.

Link: https://lore.kernel.org/all/20220309124132.291861-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: GS_CAN_FLAG_OVERFLOW: make use of BIT()

This patch converts the driver to use BIT() to define flags.

Link: https://lore.kernel.org/all/20220309124132.291861-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: sort include files alphabetically

This patch sorts the include files alphabetically.

Link: https://lore.kernel.org/all/20220309124132.291861-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix checkpatch warning

This patch fixes a checkpatch warning by converting a "unsigned" into
an "unsigned int".

Link: https://lore.kernel.org/all/20220309124132.291861-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: use consistent one space indention

With this patch a consistent one space indention throughout the whole
driver is used.

Link: https://lore.kernel.org/all/20220309124132.291861-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: change active_channels's type from atomic_t to u8

The driver uses an atomic_t variable: gs_usb:active_channels to keep
track of the number of opened channels in order to only allocate
memory for the URBs when this count changes from zero to one.

However, the driver does not decrement the counter when an error
occurs in gs_can_open(). This issue is fixed by changing the type from
atomic_t to u8 and by simplifying the logic accordingly.

It is safe to use an u8 here because the network stack big kernel lock
(a.k.a. rtnl_mutex) is being hold. For details, please refer to [1].

[1] https://lore.kernel.org/linux-can/CAMZ6Rq+sHpiw34ijPsmp7vbUpDtJwvVtdV7CvRZJsLixjAFfrg@mail.gmail.com/T/#t

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20220214234814.1321599-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_start_xmit(): zero-initialize hf->{flags,reserved}

No information is deliberately sent in hf->flags in host -> device
communications, but the open-source candleLight firmware echoes it
back, which can result in the GS_CAN_FLAG_OVERFLOW flag being set and
generating spurious ERRORFRAMEs.

While there also initialize the reserved member with 0.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20220106002952.25883-1-brian.silverman@bluerivertech.com
Link: https://github.com/candle-usb/candleLight_fw/issues/87
Cc: stable@vger.kernel.org
Signed-off-by: Brian Silverman <brian.silverman@bluerivertech.com>
[mkl: initialize the reserved member, too]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix use of uninitialized variable, detach device on reception of invalid USB data

The received data contains the channel the received data is associated
with. If the channel number is bigger than the actual number of
channels assume broken or malicious USB device and shut it down.

This fixes the error found by clang:

| drivers/net/can/usb/gs_usb.c:386:6: error: variable 'dev' is used
| uninitialized whenever 'if' condition is true
| if (hf->channel >= GS_MAX_INTF)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
| drivers/net/can/usb/gs_usb.c:474:10: note: uninitialized use occurs here
| hf, dev->gs_hf_size, gs_usb_receive_bulk_callback,
| ^~~

Link: https://lore.kernel.org/all/20211210091158.408326-1-mkl@pengutronix.de
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: do not increase tx_bytes statistics for RTR frames

The actual payload length of the CAN Remote Transmission Request (RTR)
frames is always 0, i.e. no payload is transmitted on the wire.
However, those RTR frames still use the DLC to indicate the length of
the requested frame.

As such, net_device_stats::tx_bytes should not be increased when
sending RTR frames.

The function can_get_echo_skb() already returns the correct length,
even for RTR frames (c.f. [1]). However, for historical reasons, the
drivers do not use can_get_echo_skb()'s return value and instead, most
of them store a temporary length (or dlc) in some local structure or
array. Using the return value of can_get_echo_skb() solves the
issue. After doing this, such length/dlc fields become unused and so
this patch does the adequate cleaning when needed.

This patch fixes all the CAN drivers.

Finally, can_get_echo_skb() is decorated with the __must_check
attribute in order to force future drivers to correctly use its return
value (else the compiler would emit a warning).

[1] commit ed3320cec279 ("can: dev: __can_get_echo_skb():
fix real payload length return value for RTR frames")

Link: https://lore.kernel.org/all/20211207121531.42941-6-mailhol.vincent@wanadoo.fr
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Yasushi SHOJI <yashi@spacecubics.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2
[mkl: add conversion for grcan]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: use %u to print unsigned values

This patch changes printf modifier to an unsigned int, as the printed
variables are unsigned.

Link: https://lore.kernel.org/all/20210914101005.84394-1-mkl@pengutronix.de
Cc: Roman Valls <brainstorm@nopcode.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: dev: can_free_echo_skb(): extend to return can frame length

In order to implement byte queue limits (bql) in CAN drivers, the
length of the CAN frame needs to be passed into the networking stack
even if the transmission failed for some reason.

To avoid to calculate this length twice, extend can_free_echo_skb() to
return that value. Convert all users of this function, too.

This patch is the natural extension of commit:

| 9420e1d495e2 ("can: dev: can_get_echo_skb(): extend to return can
| frame length")

Link: https://lore.kernel.org/r/20210319142700.305648-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: dev: can_get_echo_skb(): extend to return can frame length

In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.

To avoid to calculate this length twice, extend can_get_echo_skb() to return
that value. Convert all users of this function, too.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: dev: can_put_echo_skb(): extend to handle frame_len

Add a frame_len argument to can_put_echo_skb() which is used to save length of
the CAN frame into field frame_len of struct can_skb_priv so that it can be
later used after transmission completion. Convert all users of this function,
too.

Drivers which implement BQL call can_put_echo_skb() with the output of
can_skb_get_frame_len(skb) and drivers which do not simply pass zero as an
input (in the same way that NULL would be given to can_get_echo_skb()). This
way, we have a nice symmetry between the two echo functions.

Link: https://lore.kernel.org/r/20210111061335.39983-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-13-mkl@pengutronix.de
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

can: gs_usb: fix endianess problem with candleLight firmware

The firmware on the original USB2CAN by Geschwister Schneider Technologie
Entwicklungs- und Vertriebs UG exchanges all data between the host and the
device in host byte order. This is done with the struct
gs_host_config::byte_order member, which is sent first to indicate the desired
byte order.

The widely used open source firmware candleLight doesn't support this feature
and exchanges the data in little endian byte order. This breaks if a device
with candleLight firmware is used on big endianess systems.

To fix this problem, all u32 (but not the struct gs_host_frame::echo_id, which
is a transparent cookie) are converted to __le32.

Cc: Maximilian Schneider <max@schneidersoft.net>
Cc: Hubert Denkmair <hubert@denkmair.de>
Reported-by: Michael Rausch <mr@netadair.de>
Link: https://lore.kernel.org/r/b58aace7-61f3-6df7-c6df-69fee2c66906@netadair.de
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/r/20201120103818.3386964-1-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: don't include ethtool.h from netdevice.h

linux/netdevice.h is included in very many places, touching any
of its dependecies causes large incremental builds.

Drop the linux/ethtool.h include, linux/netdevice.h just needs
a forward declaration of struct ethtool_ops.

Fix all the places which made use of this implicit include.

Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Shannon Nelson <snelson@pensando.io>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Link: https://lore.kernel.org/r/20201120225052.1427503-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

can: drivers: add len8_dlc support for various CAN adapters

Support the Classical CAN raw DLC functionality to send and receive DLC values
from 9 .. 15 on various Classical CAN capable CAN network drivers:

- sja1000
- gs_usb
- pcan_usb
- pcan_usb_fd
- usb_8dev

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201111095923.2535-1-socketcan@hartkopp.net
[mkl: usb_8dev: changed indention]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: replace can_dlc as variable/element for payload length

The naming of can_dlc as element of struct can_frame and also as variable
name is misleading as it claims to be a 'data length CODE' but in reality
it always was a plain data length.

With the indroduction of a new 'len' element in struct can_frame we can now
remove can_dlc as name and make clear which of the former uses was a plain
length (-> 'len') or a data length code (-> 'dlc') value.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201120100444.3199-1-socketcan@hartkopp.net
[mkl: gs_usb: keep struct gs_host_frame::can_dlc as is]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: rename get_can_dlc() macro with can_cc_dlc2len()

The get_can_dlc() macro is used to ensure the payload length information of
the Classical CAN frame to be max 8 bytes (the CAN_MAX_DLEN).

Rename the macro and use the correct constant in preparation of the len/dlc
cleanup for Classical CAN frames.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-3-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: drivers: fix spelling mistakes

This patch fixes spelling erros found by "codespell" in the
drivers/net/can subtree.

Link: https://lore.kernel.org/r/20200915223527.1417033-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_usb_probe(): use descriptors of current altsetting

Make sure to always use the descriptors of the current alternate setting
to avoid future issues when accessing fields that may differ between
settings.

Signed-off-by: Johan Hovold <johan@kernel.org>
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_can_open(): prevent memory leak

In gs_can_open() if usb_submit_urb() fails the allocated urb should be
released.

Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 285

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license this program
is distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 100 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.918357685@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

can: gs_usb: gs_cmd_reset(): remove unused parameter "struct gs_usb *gsusb"

The 2nd parameter of gs_cmd_reset() "struct gs_usb *gsusb" is unused, so
remove it.

Suggested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix return value of the "set_bittiming" callback

The "set_bittiming" callback treats a positive return value as error!
For that reason "can_changelink()" will quit silently after setting
the bittiming values without processing ctrlmode, restart-ms, etc.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix busy loop if no more TX context is available

If sending messages with no cable connected, it quickly happens that
there is no more TX context available. Then "gs_can_start_xmit()"
returns with "NETDEV_TX_BUSY" and the upper layer does retry
immediately keeping the CPU busy. To fix that issue, I moved
"atomic_dec(&dev->active_tx_urbs)" from "gs_usb_xmit_callback()" to
the TX done handling in "gs_usb_receive_bulk_callback()". Renaming
"active_tx_urbs" to "active_tx_contexts" and moving it into
"gs_[alloc|free]_tx_context()" would also make sense.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix memory leak in gs_cmd_reset()

This patch adds the missing kfree() in gs_cmd_reset() to free the
memory that is not used anymore after usb_control_msg().

Cc: linux-stable <stable@vger.kernel.org>
Cc: Maximilian Schneider <max@schneidersoft.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: can: usb: gs_usb: Fix buffer on stack

Allocate buffers on HEAP instead of STACK for local structures
that are to be sent using usb_control_msg().

Signed-off-by: Maksim Salau <maksim.salau@gmail.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v4.8
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fix coding style

This patch fixes five minor style issues, spaces are between bitwise OR
operators.

Signed-off-by: Ethan Zonca <e@ethanzonca.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: Don't use stack memory for USB transfers

Fixes: 05ca5270005c can: gs_usb: add ethtool set_phys_id callback to locate physical device

The gs_usb driver is performing USB transfers using buffers allocated on
the stack. This causes the driver to not function with vmapped stacks.
Instead, allocate memory for the transfer buffers.

Signed-off-by: Ethan Zonca <e@ethanzonca.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v4.8
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: can: usb: gs_usb: don't print error when allocating urb fails

kmalloc will print enough information in case of failure.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: gs_usb: Add Basic support for the bytewerk.org candleLight interface

This patchs adds basic support for the bytewerk.org candleLight interface,
a open hardware (CERN OHL) USB CAN adapter.

Signed-off-by: Hubert Denkmair <hubert@denkmair.de>
Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add ethtool set_phys_id callback to locate physical device

This patch Implements the ethtool set_phys_id callback to ease the
locating of specific physical devices. Currently only supported on
candleLight interfaces.

Signed-off-by: Hubert Denkmair <hubert@denkmair.de>
Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
[mkl: split codingstyle change sinto separate patch]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: codingstyle: introduce use of BIT() + fix indention

This patch converts "1 << n" by BIT(n) and fixes the indention. No
functional change.

Signed-off-by: Hubert Denkmair <hubert@denkmair.de>
Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
[mkl: split codingstyle changes into separate patch]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: modify the usb device table to use only the first usb interface

Modified the USB device table to use only the first USB interface, as is
the case with GS USB devices. This allows other GS USB compatible
devices to be more flexible with their remaining interfaces.

Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: fixed disconnect bug by removing erroneous use of kfree()

gs_destroy_candev() erroneously calls kfree() on a struct gs_can *, which is
allocated through alloc_candev() and should instead be freed using
free_candev() alone.

The inappropriate use of kfree() causes the kernel to hang when
gs_destroy_candev() is called.

Only the struct gs_usb * which is allocated through kzalloc() should be freed
using kfree() when the device is disconnected.

Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: Fix typo in function name

This fixes typos in gs_usb.c where 'receive' is misspelled
as 'recieve'.

Signed-off-by: Nik Nyby <nikolas@gnu.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: check for kzalloc allocation failure

smatch detected the following issue:
drivers/net/can/usb/gs_usb.c:904 gs_usb_probe() error:
potential null dereference 'dev'. (kzalloc returns null)

Add a check for null return from kzalloc and return -ENOMEM

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: add .ndo_change_mtu function

Use common can_change_mtu function.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: gs_destroy_candev(): fix use after free

This patch fixes a use after free of "dev" in gs_destroy_candev().

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: gs_usb: Added support for the GS_USB CAN devices

The Geschwister Schneider Family of devices are galvanically isolated USB2.0 to
CAN2.0A/B adapters. Currently two form factors are available, a tethered dongle
in a rugged enclosure, and mini-pci-e card.

Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>