The CAN FD data bittiming constants are provided via netlink only when there
are valid CAN FD constants available in priv->data_bittiming_const.

Due to the indirection of pointer assignments in the peak_usb driver the
priv->data_bittiming_const never becomes NULL - not even for non-FD adapters.

The data_bittiming_const points to zero'ed data which leads to this result
when running 'ip -details link show can0':

35: can0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
    link/can  promiscuity 0
    can state STOPPED restart-ms 0
	  pcan_usb: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
	  : dtseg1 0..0 dtseg2 0..0 dsjw 1..0 dbrp 0..0 dbrp-inc 0  <== BROKEN!
	  clock 8000000

This patch changes the struct peak_usb_adapter::bittiming_const and struct
peak_usb_adapter::data_bittiming_const to pointers to fix the assignemnt
problems.

Cc: linux-stable <stable@vger.kernel.org> # >= 4.0
Reported-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

There is no guarantee that the skb is in the same state after calling
net_receive_skb() or netif_rx(). It might be freed or reused. Not really
harmful as its a read access, except you turn on the proper debugging options
which catch a use after free.

Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Export the ctrlmode_supported value from the core file to each adapter specific
file. This has been mandatory for supporting the new CANFD extension.
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

A "struct peak_usb_adapter" describes a certain USB adapter, as this doesn't
change during runtime, this patch marks all USB adapter definitions as const.
Acked-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

In order to be able to move the stats increment from can_bus_off() into
can_change_state(), the increment had to be moved back into code that was using
can_bus_off() but not can_change_state().

As a side-effect, this patch fixes the following bugs:
 * Redundant call to can_bus_off() in c_can.
 * Bus-off counted twice in xilinx_can.
Signed-off-by: NAndri Yngvason <andri.yngvason@marel.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch fixes the endianess definition as well as the usage of the
multi-byte fields in the data structures exchanged with the PEAK-System USB
adapters.

By fixing the endianess, this patch also fixes the wrong usage of a 32-bits
local variable for handling the error status 16-bits field, in function
pcan_usb_pro_handle_error().
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Fix possibly wrong memcpy() bytes length since some CAN records received from
PCAN-USB could define a DLC field in range [9..15].
In that case, the real DLC value MUST be used to move forward the record pointer
but, only 8 bytes max. MUST be copied into the data field of the struct
can_frame object of the skb given to the network core.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The skb->tstamp is set to the hardware timestamp when available in the USB
urb message. This leads to user visible timestamps which contain the 'uptime'
of the USB adapter - and not the usual system generated timestamp.

Fix this wrong assignment by applying the available hardware timestamp to the
skb_shared_hwtstamps data structure - which is intended for this purpose.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

That patch fixes some bad usage of two little-endian variables, which lead to
some warning/error when building the peak_usb driver.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch adds the specific part which handles the PCAN-USB adapter from
PEAK-System Technik (http://www.peak-system.com). The PCAN-USB adapter is
a sja1000 based, mono-channel USB 1.1 adapter compliant with CAN
specifications 2.0A (11-bit ID) and 2.0B (29-bit ID).
Tested-by: NOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: NWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>