can: etas_es58x: add missing a blank line after declaration

Fix below checkpatch warning:

WARNING: Missing a blank line after declarations
#2233: FILE: drivers/net/can/usb/etas_es58x/es58x_core.c:2233:
+ int ret = es58x_init_netdev(es58x_dev, ch_idx);
+ if (ret) {

Fixes: d8f26fd689dd ("can: etas_es58x: remove es58x_get_product_info()")
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20230924110914.183898-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: remove es58x_get_product_info()

Now that the product information are available under devlink, no more
need to print them in the kernel log. Remove es58x_get_product_info().

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/all/20221130174658.29282-7-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: export product information through devlink_ops::info_get()

ES58x devices report below product information through a custom usb
string:

* the firmware version
* the bootloader version
* the hardware revision

Parse this string, store the results in struct es58x_dev, export:

* the firmware version through devlink's "fw" name
* the bootloader version through devlink's "fw.bootloader" name
* the hardware revisionthrough devlink's "board.rev" name

Those devlink entries are not critical to use the device, if parsing
fails, print an informative log message and continue to probe the
device.

In addition to that, use usb_device::serial to report the device
serial number.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/all/20221130174658.29282-6-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: add devlink port support

Add support for devlink port which extends the devlink support to the
network interface level. For now, the etas_es58x driver will only rely
on the default features that devlink port has to offer and not
implement additional feature ones.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221130174658.29282-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: add devlink support

Add basic support for devlink at the device level. The callbacks of
struct devlink_ops will be implemented next.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221130174658.29282-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: sort the includes by alphabetic order

Follow the best practices, reorder the includes.

While doing so, bump up copyright year of each modified files.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221126160525.87036-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: es58x_init_netdev(): free netdev when register_candev()

In case of register_candev() fails, clear
es58x_dev->netdev[channel_idx] and add free_candev(). Otherwise
es58x_free_netdevs() will unregister the netdev that has never been
registered.

Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Arunachalam Santhanam <Arunachalam.Santhanam@in.bosch.com>
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/1668413685-23354-1-git-send-email-zhangchangzhong@huawei.com
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: etas_es58x: remove useless calls to usb_fill_bulk_urb()

Aside of urb->transfer_buffer_length and urb->context which might
change in the TX path, all the other URB parameters remains constant
during runtime. So, there is no reasons to call usb_fill_bulk_urb()
each time before submitting an URB.

Make sure to initialize all the fields of the URB at allocation
time. For the TX branch, replace the call usb_fill_bulk_urb() by an
assignment of urb->context. urb->urb->transfer_buffer_length is
already set by the caller functions, no need to set it again. For the
RX branch, because all parameters are unchanged, simply remove the
call to usb_fill_bulk_urb().

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220729080902.25839-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: advertise timestamping capabilities and add ioctl support

Currently, userland has no method to query which timestamping features
are supported by the etas_es58x driver (aside maybe of getting RX
messages and observe whether or not hardware timestamps stay at zero).

The canonical way for a network driver to advertise what kind of
timestamping is supports is to implement
ethtool_ops::get_ts_info(). Here, we use the CAN specific
can_ethtool_op_get_ts_info_hwts() function to achieve this.

In addition, the driver currently does not support the hardware
timestamps ioctls. According to [1], SIOCSHWTSTAMP is "must" and
SIOCGHWTSTAMP is "should". This patch fills up that gap by
implementing net_device_ops::ndo_eth_ioctl() using the CAN specific
function can_eth_ioctl_hwts().

[1] kernel doc Timestamping, section 3.1: "Hardware Timestamping
Implementation: Device Drivers"
Link: https://docs.kernel.org/networking/timestamping.html#hardware-timestamping-implementation-device-drivers

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-11-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: remove DRV_VERSION

DRV_VERSION is a leftover from when the driver was an out of tree
module. The driver version was never incremented despite of the
numerous changes made since it was mainstreamed. Keeping an
unmaintained driver version number makes no sense. Remove it and rely
on the kernel version instead.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220726082707.58758-11-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: replace ES58X_MODULE_NAME with KBUILD_MODNAME

ES58X_MODULE_NAME is set to "etas_es58x". KBUILD_MODNAME also
evaluates to "etas_es58x". Get rid of ES58X_MODULE_NAME and rely on
KBUILD_MODNAME instead.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220726082707.58758-10-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: replace es58x_device::rx_max_packet_size by usb_maxpacket()

The field rx_max_packet_size of struct es58x_device in nothing else
than usb_endpoint_descriptor::wMaxPacketSize and can be easily
retrieved using usb_maxpacket(). Also, rx_max_packet_size being used a
single time, there is no merit to cache it locally.

Remove es58x_device::rx_max_packet_size and rely on usb_maxpacket()
instead.

Link: https://lore.kernel.org/all/20220611162037.1507-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: change opened_channel_cnt's type from atomic_t to u8

The driver uses an atomic_t variable: struct
es58x_device::opened_channel_cnt 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.

While the intent was to prevent race conditions, the choice of an
atomic_t turns out to be a bad idea for several reasons:

- implementation is incorrect and fails to decrement
opened_channel_cnt when the URB allocation fails as reported in
[1].

- even if opened_channel_cnt were to be correctly decremented,
atomic_t is insufficient to cover edge cases: there can be a race
condition in which 1/ a first process fails to allocate URBs
memory 2/ a second process enters es58x_open() before the first
process does its cleanup and decrements opened_channed_cnt. In
which case, the second process would successfully return despite
the URBs memory not being allocated.

- actually, any kind of locking mechanism was useless here because
it is redundant with the network stack big kernel lock
(a.k.a. rtnl_lock) which is being hold by all the callers of
net_device_ops:ndo_open() and net_device_ops:ndo_close(). c.f. the
ASSERST_RTNL() calls in __dev_open() [2] and __dev_close_many()
[3].

The atmomic_t is thus replaced by a simple u8 type and the logic to
increment and decrement es58x_device:opened_channel_cnt is simplified
accordingly fixing the bug reported in [1]. We do not check again for
ASSERST_RTNL() as this is already done by the callers.

[1] https://lore.kernel.org/linux-can/20220201140351.GA2548@kili/T/#u
[2] https://elixir.bootlin.com/linux/v5.16/source/net/core/dev.c#L1463
[3] https://elixir.bootlin.com/linux/v5.16/source/net/core/dev.c#L1541

Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Link: https://lore.kernel.org/all/20220212112713.577957-1-mailhol.vincent@wanadoo.fr
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: do not increase rx statistics when generating a CAN rx error message frame

The CAN error message frames (i.e. error skb) are an interface
specific to socket CAN. The payload of the CAN error message frames
does not correspond to any actual data sent on the wire. Only an error
flag and a delimiter are transmitted when an error occurs (c.f. ISO
11898-1 section 10.4.4.2 "Error flag").

For this reason, it makes no sense to increment the rx_packets and
rx_bytes fields of struct net_device_stats because no actual payload
were transmitted on the wire.

This patch fixes all the CAN drivers.

Link: https://lore.kernel.org/all/20211207121531.42941-2-mailhol.vincent@wanadoo.fr
CC: Marc Kleine-Budde <mkl@pengutronix.de>
CC: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Alexandre Belloni <alexandre.belloni@bootlin.com>
CC: Ludovic Desroches <ludovic.desroches@microchip.com>
CC: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
CC: Maxime Ripard <mripard@kernel.org>
CC: Chen-Yu Tsai <wens@csie.org>
CC: Jernej Skrabec <jernej.skrabec@gmail.com>
CC: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
CC: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
CC: Michal Simek <michal.simek@xilinx.com>
CC: Stephane Grosjean <s.grosjean@peak-system.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
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: es58x_init_netdev: populate net_device::dev_port

The field dev_port of struct net_device indicates the port number of a
network device [1]. This patch populates this field.

This field can be helpful to distinguish between the two network
interfaces of a dual channel device (i.e. ES581.4 or ES582.1). Indeed,
at the moment, all the network interfaces of a same device share the
same static udev attributes c.f. output of:

| udevadm info --attribute-walk /sys/class/net/canX

The dev_port attribute can then be used to write some udev rules to,
for example, assign a permanent name to each network interface based
on the serial/dev_port pair (which is convenient when you have a test
bench with several CAN devices connected simultaneously and wish to
keep consistent interface names upon reboot).

[1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-net

Link: https://lore.kernel.org/all/20211026180553.1953189-1-mailhol.vincent@wanadoo.fr
Suggested-by: Lukas Magel <lukas.magel@escrypt.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: es58x_rx_err_msg(): fix memory leak in error path

In es58x_rx_err_msg(), if can->do_set_mode() fails, the function
directly returns without calling netif_rx(skb). This means that the
skb previously allocated by alloc_can_err_skb() is not freed. In other
terms, this is a memory leak.

This patch simply removes the return statement in the error branch and
let the function continue.

Issue was found with GCC -fanalyzer, please follow the link below for
details.

Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Link: https://lore.kernel.org/all/20211026180740.1953265-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: use sizeof and sizeof_field macros instead of constant values

Replace two constant values by a call to sizeof{,_field} on the
relevant field to make the logic easier to understand.

Link: https://lore.kernel.org/r/20210628155420.1176217-6-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: add es58x_free_netdevs() to factorize code

Both es58x_probe() and es58x_disconnect() use a similar code snippet
to release the netdev resources. Factorize it in an helper function
named es58x_free_netdevs().

Link: https://lore.kernel.org/r/20210628155420.1176217-5-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: use devm_kzalloc() to allocate device resources

Replace kzalloc() with devm_kzalloc(). By doing this, we do not need
to care anymore about having to call kfree(). This result in a
simpler and more easy to read code.

Link: https://lore.kernel.org/r/20210628155420.1176217-4-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: use error pointer during device probing

Make es58x_init_es58x_dev return a pointer to the allocated structure
instead of returning an integer. Errors are handled through the helper
function ERR_PTR and IS_ERR.

This slightly simplifies the code.

Link: https://lore.kernel.org/r/20210628155420.1176217-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: fix three typos in author name and documentation

Change the author name from "lastname firstname" to "firstname
lastname".

Fix a typo in a variable name in the documentation of struct
es58x_parameters::fifo_mask.

Fix a typo in the title of the datasheet (E701 -> E70) and re-indent
the comments.

Link: https://lore.kernel.org/r/20210628155420.1176217-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: Fix a couple of spelling mistakes

There are spelling mistakes in netdev_dbg and netdev_dbg messages,
fix these.

Link: https://lore.kernel.org/r/20210415113050.1942333-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: fix null pointer dereference when handling error frames

During the handling of CAN bus errors, a CAN error SKB is allocated
using alloc_can_err_skb(). Even if the allocation of the SKB fails,
the function continues in order to do the stats handling.

All access to the can_frame pointer (cf) should be guarded by an if
statement:
if (cf)

However, the increment of the rx_bytes stats:
netdev->stats.rx_bytes += cf->can_dlc;
dereferences the cf pointer and was not guarded by an if condition
leading to a NULL pointer dereference if the can_err_skb() function
failed.

Replacing the cf->can_dlc by the macro CAN_ERR_DLC (which is the
length of any CAN error frames) solves this NULL pointer dereference.

Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Link: https://lore.kernel.org/r/20210413114242.2760-1-mailhol.vincent@wanadoo.fr
Reported-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: add support for the ETAS ES58X_FD CAN USB interfaces

This patch add support for the ES582.1 and ES584.1 interfaces from
ETAS GmbH (https://www.etas.com/en/products/es58x.php).

Link: https://lore.kernel.org/r/20210410095948.233305-4-mailhol.vincent@wanadoo.fr
Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: add support for ETAS ES581.4 CAN USB interface

This patch adds support for the ES581.4 interface from ETAS
GmbH (https://www.etas.com/en/products/es58x.php).

Link: https://lore.kernel.org/r/20210410095948.233305-3-mailhol.vincent@wanadoo.fr
Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces

This patch adds the core support for various USB CAN interfaces from
ETAS GmbH (https://www.etas.com/en/products/es58x.php). The next
patches add the glue code drivers for the individual interfaces.

Link: https://lore.kernel.org/r/20210410095948.233305-2-mailhol.vincent@wanadoo.fr
Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>