After sending a RTR frame the TX mailbox becomes a RX_EMPTY mailbox. To avoid
side effects when the RX-FIFO is full, this patch puts the TX mailbox into
TX_INACTIVE mode in the transmission complete interrupt handler. This, of
course, leaves a race window between the actual completion of the transmission
and the handling of tx-complete interrupt. However this is the best we can do
without busy polling the tx complete interrupt.

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

This patch implements the workaround mentioned in ERR005829:

    ERR005829: FlexCAN: FlexCAN does not transmit a message that is enabled to
    be transmitted in a specific moment during the arbitration process.

Workaround: The workaround consists of two extra steps after setting up a
message for transmission:

Step 8: Reserve the first valid mailbox as an inactive mailbox (CODE=0b1000).
If RX FIFO is disabled, this mailbox must be message buffer 0. Otherwise, the
first valid mailbox can be found using the "RX FIFO filters" table in the
FlexCAN chapter of the chip reference manual.

Step 9: Write twice INACTIVE code (0b1000) into the first valid mailbox.
Signed-off-by: NDavid Jander <david@protonic.nl>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Apparently mailboxes may contain random data at startup, causing some of them
being prepared for message reception. This causes overruns being missed or even
confusing the IRQ check for trasmitted messages, increasing the transmit
counter instead of the error counter.

This patch initializes all mailboxes after the FIFO as RX_INACTIVE.
Signed-off-by: NDavid Jander <david@protonic.nl>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch fixes the initialization of the TX mailbox. It is now correctly
initialized as TX_INACTIVE not RX_EMPTY.

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

Apparently can_restart() runs from a (timer-) interrupt and can call
flexcan_chip_[en|dis]able(), so avoid using usleep_range()
Signed-off-by: NDavid Jander <david@protonic.nl>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Once the CAN-bus is open and a packet is sent, the controller switches
into the PASSIVE state. Once the BUS is closed again it goes the back
err-warning. The TX error counter goes 0 -> 0x80 -> 0x7f.
This patch makes sure that the user learns about this state chang
(CAN_STATE_ERROR_WARNING => CAN_STATE_ERROR_PASSIVE)
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NMatthias Klein <matthias.klein@optimeas.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

In case we don't have FLEXCAN_HAS_BROKEN_ERR_STATE and the user set
CAN_CTRLMODE_BERR_REPORTING once it can not be unset again until reboot.
So in case neither hardware nor user wants the error interrupt disable
the bit.
Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD).
Setting the MTU to other values is pointless but it does not really hurt.
With the introduction of the CAN FD support in drivers/net/can a new
function to switch the MTU for CAN FD has been introduced.

This patch makes use of this can_change_mtu() function to check for correct
MTU settings also in legacy CAN (2.0) devices.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch replaces an open coded pdev->id_entry by platform_get_device_id().
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch removes #ifdef CONFIG_PM_SLEEP to improve compile coverage.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch moves the soft reset into a seperate function.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch adds the missing netif_napi_del() to the flexcan_remove() function.

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

This patch factors out freeze and unfreeze of the CAN core into seperate
functions. Experiments have shown that the transition from and to freeze mode
may take several microseconds, especially the time entering the freeze mode
depends on the current bitrate.

This patch adds a while loop which polls the Freeze Mode ACK bit (FRZ_ACK) that
indicates a successfull mode change. If the function runs into a timeout a
error value is returned.

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

This patch moves the transceiver enable and disable into seperate functions,
where the NULL pointer check is hidden.

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

In flexcan_chip_enable() and flexcan_chip_disable() fixed delays are used.
Experiments have shown that the transition from and to low power mode may take
several microseconds.

This patch adds a while loop which polls the Low Power Mode ACK bit (LPM_ACK)
that indicates a successfull mode change. If the function runs into a timeout a
error value is returned.

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

If flexcan_chip_start() in flexcan_open() fails, the interrupt is not freed,
this patch adds the missing cleanup.

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

When shutting down the CAN interface (ifconfig canX down) during high CAN bus
loads, the CAN core might hang and freeze the whole CPU.

This patch fixes the shutdown sequence by first disabling the CAN core then
disabling all interrupts.

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

There is no reason to disallow building the driver on big-endian ARM kernels.
Furthermore, the current behavior is actually broken on little-endian PowerPC
as well.

The choice of register accessor functions must purely depend on the CPU
architecture, not which endianess the CPU is running on. Note that we nowadays
allow both big-endian ARM and little-endian PowerPC kernels.

With this patch applied, we will do the right thing in all four combinations.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The flexcan IP core uses the peripheral clock ("per") as basic clock for the
bit timing calculation. However the driver uses the the wrong clock ("ipg").
This leads to wrong bit rates if the rates on both clock are different.

This patch fixes the problem by using the correct clock for the bit rate
calculation.

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

The current implemetation of of_match_device() relies that the of_device_id
table in the driver is sorted from most specific to least specific compatible.

Without this patch the mx28 is detected as the less specific p1010. This leads
to a p1010 specific workaround is activated on the mx28, which is not needed.

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

In patch

    0d1862ea can: flexcan: fix flexcan_chip_start() on imx6

the loop in flexcan_chip_start() that iterates over all mailboxes after the
soft reset of the CAN core was removed. This loop put all mailboxes (even the
ones marked as reserved 1...7) into EMPTY/INACTIVE mode. On mailboxes 8...63,
this aborts any pending TX messages.

After a cold boot there is random garbage in the mailboxes, which leads to
spontaneous transmit of CAN frames during first activation. Further if the
interface was disabled with a pending message (usually due to an error
condition on the CAN bus), this message is retransmitted after enabling the
interface again.

This patch fixes the regression by:
1) Limiting the maximum number of used mailboxes to 8, 0...7 are used by the RX
FIFO, 8 is used by TX.
2) Marking the TX mailbox as EMPTY/INACTIVE, so that any pending TX of that
mailbox is aborted.

Cc: linux-stable <stable@vger.kernel.org>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

In the flexcan_chip_start() function first the flexcan core is going through
the soft reset sequence, then the RX FIFO is enabled.

With the hardware is put into FIFO mode, message buffers 1...7 are reserved by
the FIFO engine. The remaining message buffers are in reset default values.
This patch removes the bogus initialization of the message buffers, as it
causes an imprecise external abort on imx6.

Cc: linux-stable <stable@vger.kernel.org>
Reported-by: NLothar Waßmann <LW@KARO-electronics.de>
Tested-by: NLothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly. This is a cosmetic change
to make the code simpler and enhance the readability.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_set_drvdata() with &pdev->dev,
so we can directly pass a struct platform_device.
Signed-off-by: NLibo Chen <libo.chen@huawei.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Using devm_ioremap_resource() can make the code simpler and smaller.

Also, place alloc_candev() after of_match_device() to make error handling
easier.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Instead of using a GPIO to turn on/off the CAN transceiver, it is better to
use a regulator as some systems may use a PMIC to power the CAN transceiver.
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Using SIMPLE_DEV_PM_OPS can make the code smaller and simpler.

Also change CONFIG_PM to CONFIG_PM_SLEEP.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Since commit ab78029e (drivers/pinctrl: grab default handles from device core)
we can rely on device core for handling pinctrl, so remove
devm_pinctrl_get_select_default() from the driver.

Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: <linux-can@vger.kernel.org>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d063
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Add support for canbus activity led indicators on flexcan devices by
calling appropriate can_led_* functions.

These are only enabled when CONFIG_CAN_LEDS is Y, becomes no-op
otherwise.

Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NFabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds a MODULE_DEVICE_TABLE for the of and platform bindings, so that
the module can be loaded automatically by udev.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch adds some Flexcan version info and removes the feature flag
FLEXCAN_HAS_BROKEN_ERR_STATE for the i.MX6Q. It also has the line [TR]WRN_INT
properly connected.

Cc: Hui Wang <jason77.wang@gmail.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NWolfgang Grandegger <wg@grandegger.com>
[mkl: convert to incremental patch]
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Due to a bug in most Flexcan cores, the bus error interrupt needs
to be enabled. Otherwise we don't get any error warning or passive
interrupts. This is _not_ necessary for the i.MX28 and this patch
disables bus error interrupts if "berr-reporting" is not requested.
This avoids bus error flooding, which might harm, especially on
low-end systems.

To handle such quirks of the Flexcan cores, a hardware feature flag
has been introduced, also replacing the "hw_ver" variable. So far
nobody could tell what Flexcan core version is available on what
Freescale SOC, apart from the i.MX6Q and P1010, and which bugs or
features are present on the various "hw_rev".

CC: Hui Wang <jason77.wang@gmail.com>
CC: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for a second clock to the flexcan driver. On
modern freescale ARM cores like the imx53 and imx6q two clocks ("ipg"
and "per") must be enabled in order to access the CAN core.

In the original driver, the clock was requested without specifying the
connection id, further all mainline ARM archs with flexcan support
(imx28, imx25, imx35) register their flexcan clock without a
connection id, too.

This patch first renames the existing clk variable to clk_ipg and
converts it to devm for easier error handling. The connection id "ipg"
is added to the devm_clk_get() call. Then a second clock "per" is
requested. As all archs don't specify a connection id, both clk_get
return the same clock. This ensures compatibility to existing flexcan
support and adds support for imx53 at the same time.

After this patch hits mainline, the archs may give their existing
flexcan clock the "ipg" connection id and implement a dummy "per"
clock.

This patch has been tested on imx28 (unmodified clk tree) and on imx53
with a seperate "ipg" and "per" clock.

Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Acked-by: NHui Wang <jason77.wang@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch marks the bittiming_const pointer as in the struct can_pric as
"const". This allows us to mark the struct can_bittiming_const in the CAN
drivers as "const", too.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

At least in the i.MX series, the flexcan contrller divides into ver_3
and ver_10, current driver is for ver_3 controller.

i.MX6 has ver_10 controller, it has more reigsters than ver_3 has.
The rxfgmask (Rx FIFO Global Mask) register is one of the new added.
Its reset value is 0xffffffff, this means ID Filter Table must be
checked when receive a packet, but the driver is designed to accept
everything during the chip start, we need to clear this register to
follow this design.

Use the data entry of the struct of_device_id to point chip specific
info, we can set hardware version for each platform.

Cc: linux-can@vger.kernel.org
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NHui Wang <jason77.wang@gmail.com>
[mkl: add id_table support]
Tested-by: NHui Wang <jason77.wang@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

of_property_read_u32() can auto handle endian problems, use this
function can make code clean and simple.

No need to check return value here since the following got value
check will handle this.

Cc: linux-can@vger.kernel.org
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NHui Wang <jason77.wang@gmail.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>