The assignment 'cf->data[2] |= CAN_ERR_PROT_UNSPEC' used at CAN error message
creation time is obsolete as CAN_ERR_PROT_UNSPEC is zero and cf->data[2] is
initialized with zero in alloc_can_err_skb() anyway.

So we could either assign 'cf->data[2] = CAN_ERR_PROT_UNSPEC' correctly or we
can remove the obsolete OR operation entirely.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

As Dan Carpenter reported in http://marc.info/?l=linux-can&m=144793696016187
the assignment of the error location in CAN error messages had some bit wise
overlaps. Indeed the value to be assigned in data[3] is no bitfield but defines
a single value which points to a location inside the CAN frame on the wire.

This patch fixes the assignments for the error locations in error messages.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch removes the return from the void function m_can_fifo_write().
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>

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

Bosch M_CAN is CAN FD capable device. This patch implements the CAN
FD features include up to 64 bytes payload and bitrate switch function.
1) Change the Rx FIFO and Tx Buffer to 64 bytes for support CAN FD
   up to 64 bytes payload. It's backward compatible with old 8 bytes
   normal CAN frame.
2) Allocate can frame or canfd frame based on EDL bit
3) Bitrate Switch function is disabled by default and will be enabled
   according to CANFD_BRS bit in cf->flags.
Acked-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Fix a few error messages.
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The spec mentions there may be a delay until the value written to INIT can be
read back due to the synchronization mechanism between the two clock domains.
But it does not indicate the exact clock cycles needed. The 5us delay is a
test value and seems ok.

Without the delay, CCCR.CCE bit may fail to be set and then the initialization
fail sometimes when do repeatly up and down.
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The original code missed to set the cf->can_dlc in the RTR case, so add it.
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The m_can_get_berr_counter function can sleep and it may be called in napi poll
function. Rework it to fix the following warning.

root@imx6qdlsolo:~# cangen can0 -f -L 12 -D 112233445566778899001122
[ 1846.017565] m_can 20e8000.can can0: entered error warning state
[ 1846.023551] ------------[ cut here ]------------
[ 1846.028216] WARNING: CPU: 0 PID: 560 at kernel/locking/mutex.c:867 mutex_trylock+0x218/0x23c()
[ 1846.036889] DEBUG_LOCKS_WARN_ON(in_interrupt())
[ 1846.041263] Modules linked in:
[ 1846.044594] CPU: 0 PID: 560 Comm: cangen Not tainted 3.17.0-rc4-next-20140915-00010-g032d018-dirty #477
[ 1846.054033] Backtrace:
[ 1846.056557] [<80012448>] (dump_backtrace) from [<80012728>] (show_stack+0x18/0x1c)
[ 1846.064180]  r6:809a07ec r5:809a07ec r4:00000000 r3:00000000
[ 1846.069966] [<80012710>] (show_stack) from [<806c9ee0>] (dump_stack+0x8c/0xa4)
[ 1846.077264] [<806c9e54>] (dump_stack) from [<8002aa78>] (warn_slowpath_common+0x70/0x94)
[ 1846.085403]  r6:806cd1b0 r5:00000009 r4:be1d5c20 r3:be07b0c0
[ 1846.091204] [<8002aa08>] (warn_slowpath_common) from [<8002aad4>] (warn_slowpath_fmt+0x38/0x40)
[ 1846.099951]  r8:8119106c r7:80515aa4 r6:be027000 r5:00000001 r4:809d1df4
[ 1846.106830] [<8002aaa0>] (warn_slowpath_fmt) from [<806cd1b0>] (mutex_trylock+0x218/0x23c)
[ 1846.115141]  r3:80851c88 r2:8084fb74
[ 1846.118804] [<806ccf98>] (mutex_trylock) from [<80515aa4>] (clk_prepare_lock+0x14/0xf4)
[ 1846.126859]  r8:00000040 r7:be1d5cec r6:be027000 r5:be255800 r4:be027000
[ 1846.133737] [<80515a90>] (clk_prepare_lock) from [<80517660>] (clk_prepare+0x14/0x2c)
[ 1846.141583]  r5:be255800 r4:be027000
[ 1846.145272] [<8051764c>] (clk_prepare) from [<8041ff14>] (m_can_get_berr_counter+0x20/0xd4)
[ 1846.153672]  r4:be255800 r3:be07b0c0
[ 1846.157325] [<8041fef4>] (m_can_get_berr_counter) from [<80420428>] (m_can_poll+0x310/0x8fc)
[ 1846.165809]  r7:bd4dc540 r6:00000744 r5:11300000 r4:be255800
[ 1846.171590] [<80420118>] (m_can_poll) from [<8056a468>] (net_rx_action+0xcc/0x1b4)
[ 1846.179204]  r10:00000101 r9:be255ebc r8:00000040 r7:be7c3208 r6:8097c100 r5:be7c3200
[ 1846.187192]  r4:0000012c
[ 1846.189779] [<8056a39c>] (net_rx_action) from [<8002deec>] (__do_softirq+0xfc/0x2c4)
[ 1846.197568]  r10:00000101 r9:8097c088 r8:00000003 r7:8097c080 r6:40000001 r5:8097c08c
[ 1846.205559]  r4:00000020
[ 1846.208144] [<8002ddf0>] (__do_softirq) from [<8002e194>] (do_softirq+0x7c/0x88)
[ 1846.215588]  r10:00000000 r9:bd516a60 r8:be18ce00 r7:00000000 r6:be255800 r5:8056c0ec
[ 1846.223578]  r4:60000093
[ 1846.226163] [<8002e118>] (do_softirq) from [<8002e288>] (__local_bh_enable_ip+0xe8/0x10c)
[ 1846.234386]  r4:00000200 r3:be1d4000
[ 1846.238036] [<8002e1a0>] (__local_bh_enable_ip) from [<8056c108>] (__dev_queue_xmit+0x314/0x6b0)
[ 1846.246868]  r6:be255800 r5:bd516a00 r4:00000000 r3:be07b0c0
[ 1846.252645] [<8056bdf4>] (__dev_queue_xmit) from [<8056c4b8>] (dev_queue_xmit+0x14/0x18)
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The M_CAN message RAM is usually equipped with a parity or ECC functionality.
But RAM cells suffer a hardware reset and can therefore hold arbitrary content
at startup - including parity and/or ECC bits.

To prevent the M_CAN controller detecting checksum errors when reading
potentially uninitialized TX message RAM content to transmit CAN frames the TX
message RAM has to be written with (any kind of) initial data.
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Use common can_change_mtu function.
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The patch adds the basic CAN TX/RX function support for Bosch M_CAN controller.
For TX, only one dedicated tx buffer is used for sending data.
For RX, RXFIFO 0 is used for receiving data to avoid overflow.
Rx FIFO 1 and Rx Buffers are not used currently, as well as Tx Event FIFO.

Due to the message ram can be shared by multi m_can instances
and the fifo element is configurable which is SoC dependant,
the design is to parse the message ram related configuration data from device
tree rather than hardcode define it in driver which can make the message
ram sharing fully transparent to M_CAN controller driver,
then we can gain better driver maintainability and future features upgrade.

M_CAN also supports CANFD protocol features like data payload up to 64 bytes
and bitrate switch at runtime, however, this patch still does not add the
support for these features.

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Varka Bhadram <varkabhadram@gmail.com>
Signed-off-by: NDong Aisheng <b29396@freescale.com>
Reviewed-by: NVarka Bhadram <varkabhadram@gmail.com>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
[mkl: Squahed semicolon cleanup by Fengguang Wu]
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>