The helper functions can_len2dlc and can_dlc2len are only relevant for
CAN FD data length code (DLC) conversion.

To fit the introduced can_cc_dlc2len for Classical CAN we rename:

can_dlc2len -> can_fd_dlc2len to get the payload length from the DLC
can_len2dlc -> can_fd_len2dlc to get the DLC from the payload length
Suggested-by: NVincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-6-socketcan@hartkopp.netSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

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: NOliver 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: NMarc Kleine-Budde <mkl@pengutronix.de>

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

Avoid processing bogus interrupt statuses when the HW is runtime suspended and
the M_CAN_IR register read may get all bits 1's. Handler can be called if the
interrupt request is shared with other peripherals or at the end of free_irq().

Therefore check the runtime suspended status before processing.

Fixes: cdf8259d ("can: m_can: Add PM Support")
Signed-off-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20200915134715.696303-1-jarkko.nikula@linux.intel.comSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

There might be some requests pending in the buffer when the interface close
sequence occurs. In some devices, these pending requests might lead to the
module not shutting down properly when m_can_clk_stop() is called.

Therefore, move the device to init state before potentially powering it down.

Fixes: e0d1f481 ("can: m_can: add Bosch M_CAN controller support")
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Acked-by: NDan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200825055442.16994-1-faiz_abbas@ti.comSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Fix leaking netdev device from peripherial devices. The call to allocate the
netdev device is made from and managed by the peripherial.

Fixes: f524f829 ("can: m_can: Create a m_can platform framework")
Reported-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDan Murphy <dmurphy@ti.com>
Link: http://lore.kernel.org/r/20200227183829.21854-2-dmurphy@ti.comSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch creates a common function that peripherials can call to free the
netdev device when failures occur.

Fixes: f524f829 ("can: m_can: Create a m_can platform framework")
Reported-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NDan Murphy <dmurphy@ti.com>
Link: http://lore.kernel.org/r/20200227183829.21854-2-dmurphy@ti.comSigned-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

m_can_handle_state_change() is called with the new_state as an argument.

In the switch statements for CAN_STATE_ERROR_ACTIVE, the comment and the
following code indicate that a CAN_STATE_ERROR_WARNING is handled.

This patch fixes this problem by changing the case to CAN_STATE_ERROR_WARNING.
Signed-off-by: NWu Bo <wubo.oduw@gmail.com>
Link: http://lore.kernel.org/r/20200129022330.21248-2-wubo.oduw@gmail.com
Cc: Dan Murphy <dmurphy@ti.com>
Fixes: e0d1f481 ("can: m_can: add Bosch M_CAN controller support")
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The Bosch MCAN hardware (3.1.0 and above) supports interrupt flag to
detect Protocol error in arbitration phase.

Transmit error statistics is currently not updated from the MCAN driver.
Protocol error in arbitration phase is a TX error and the network
statistics should be updated accordingly.

The member "tx_error" of "struct net_device_stats" should be incremented
as arbitration is a transmit protocol error. Also "arbitration_lost" of
"struct can_device_stats" should be incremented to report arbitration
lost.
Signed-off-by: NPankaj Sharma <pankj.sharma@samsung.com>
Signed-off-by: NSriram Dash <sriram.dash@samsung.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

According to the CAN Specification (see ISO 11898-1:2015, 8.3.4
Recovery Management), the M_CAN provides means for automatic
retransmission of frames that have lost arbitration or that
have been disturbed by errors during transmission. By default
automatic retransmission is enabled.

The Bosch MCAN controller has support for disabling automatic
retransmission.

To support time-triggered communication as described in ISO
11898-1:2015, chapter 9.2, the automatic retransmission may be
disabled via CCCR.DAR.

CAN_CTRLMODE_ONE_SHOT is used for disabling automatic retransmission.
Signed-off-by: NPankaj Sharma <pankj.sharma@samsung.com>
Signed-off-by: NSriram Dash <sriram.dash@samsung.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Rename the common m_can_priv class structure to m_can_classdev as this
is more descriptive.
Acked-by: NWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NDan Murphy <dmurphy@ti.com>
Acked-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Create a m_can platform framework that peripheral
devices can register to and use common code and register sets.
The peripheral devices may provide read/write and configuration
support of the IP.
Acked-by: NWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NDan Murphy <dmurphy@ti.com>
Acked-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Fix checkpatch issues found during the m_can framework creation, before
framework creation in the following patches.

Fix these 4 check issues:
CHECK: Unnecessary parentheses around 'cdev->can.state != CAN_STATE_ERROR_WARNING'
	if (psr & PSR_EW &&
	    (cdev->can.state != CAN_STATE_ERROR_WARNING)) {

CHECK: Unnecessary parentheses around 'cdev->can.state != CAN_STATE_ERROR_PASSIVE'
	if ((psr & PSR_EP) &&
	    (cdev->can.state != CAN_STATE_ERROR_PASSIVE)) {

CHECK: Unnecessary parentheses around 'cdev->can.state != CAN_STATE_BUS_OFF'
	if ((psr & PSR_BO) &&
	    (cdev->can.state != CAN_STATE_BUS_OFF)) {

CHECK: Unnecessary parentheses around 'priv->version <= 31'
	if ((priv->version <= 31) && (irqstatus & IR_MRAF) &&
	    (m_can_read(priv, M_CAN_ECR) & ECR_RP)) {
Signed-off-by: NDan Murphy <dmurphy@ti.com>
Acked-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

During frame reception while the MCAN is in Error Passive state and the
Receive Error Counter has thevalue MCAN_ECR.REC = 127, it may happen
that MCAN_IR.MRAF is set although there was no Message RAM access
failure. If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is
generated.

Work around:
The Message RAM Access Failure interrupt routine needs to check whether

    MCAN_ECR.RP = '1' and MCAN_ECR.REC = '127'.

In this case, reset MCAN_IR.MRAF. No further action is required.
This affects versions older than 3.2.0

Errata explained on Sama5d2 SoC which includes this hardware block:
http://ww1.microchip.com/downloads/en/DeviceDoc/SAMA5D2-Family-Silicon-Errata-and-Data-Sheet-Clarification-DS80000803B.pdf
chapter 6.2

Reproducibility: If 2 devices with m_can are connected back to back,
configuring different bitrate on them will lead to interrupt storm on
the receiving side, with error "Message RAM access failure occurred".
Another way is to have a bad hardware connection. Bad wire connection
can lead to this issue as well.

This patch fixes the issue according to provided workaround.
Signed-off-by: NEugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: NLudovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

MCAN message ram should only be accessed once clocks are enabled.
Therefore, move the call to parse/init the message ram to after
clocks are enabled.
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

pm_runtime_get_sync() returns a 1 if the state of the device is already
'active'. This is not a failure case and should return a success.

Therefore fix error handling for pm_runtime_get_sync() call such that
it returns success when the value is 1.

Also cleanup the TODO for using runtime PM for sleep mode as that is
implemented.
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Cc: <stable@vger.kernel.org
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Inside m_can_chip_config(), when setting up the new value of the CCCR,
the CCCR_NISO bit is not cleared like the others, CCCR_TEST, CCCR_MON,
CCCR_BRSE and CCCR_FDOE, before checking the can.ctrlmode bits for
CAN_CTRLMODE_FD_NON_ISO.

This way once the controller was configured for CAN_CTRLMODE_FD_NON_ISO,
this mode could never be cleared again.

This fix is only relevant for controllers with version 3.1.x or 3.2.x.
Older versions do not support NISO.
Signed-off-by: NRoman Fietze <roman.fietze@telemotive.de>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Make sure to apply the correct pin state in suspend/resume callbacks.
Putting pins in sleep state saves power.
Signed-off-by: NBich Hemon <bich.hemon@st.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Due to a typo, the mask was destroyed by a comparison instead of a bit
shift.
Reported-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Building without CONFIG_PM results in a harmless warning:

drivers/net/can/m_can/m_can.c:1763:12: error: 'm_can_runtime_resume' defined but not used [-Werror=unused-function]
drivers/net/can/m_can/m_can.c:1752:12: error: 'm_can_runtime_suspend' defined but not used [-Werror=unused-function]

Marking the functions as __maybe_unused lets the compiler
silently drop them instead.

Fixes: cdf8259d ("can: m_can: Add PM Support")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Add call to new generic functions that provides support via a binding
to limit the arbitration rate and/or data rate imposed by the physical
transceiver connected to the MCAN peripheral.
Signed-off-by: NFranklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Add support for CONFIG_PM which is the new way to handle managing clocks.

Move the clock management to pm_runtime_resume() and pm_runtime_suspend()
callbacks for the driver.

CONFIG_PM is required by OMAP based devices to handle clock management.
Therefore, this allows future Texas Instruments SoCs that have the MCAN IP
to work with this driver.
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

As the previous patch removed alloc_m_can_dev(), let's get rid of the
corresponding free_m_can_dev() and call free_candev() directly.
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

With the version no longer required to allocate the net device, it can
be moved to probe and the alloc_m_can_dev() function can be simplified.

Therefore, move the allocation of net device to probe and change
alloc_m_can_dev() to setup_m_can_dev().
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

Currently the m_can version is used to set the tx_fifo_count to 1 when
allocating the net device. However, this is redundant as a value of 1
for the tx_fifo_count needs to be provided in the bosch,mram-cfg
property of the device tree node anyway.

Therefore, remove check for version when allocating the net device.
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

During test transmitting using CAN-FD at high bitrates (> 2 Mbps)
would fail. Scoping the signals I noticed that only a single bit
was being transmitted and with a bit more investigation realized the
actual MCAN IP would go back to initialization mode automatically.

It appears this issue is due to the MCAN needing to use the Transmitter
Delay Compensation Mode with the correct value for the transmitter delay
compensation offset (tdco). What impacts the tdco value isn't 100% clear
but to calculate it you use an equation defined in the MCAN User's Guide.

The user guide mentions that this register needs to be set based on clock
values, secondary sample point and the data bitrate. One of the key
variables that can't automatically be determined is the secondary
sample point (ssp). This ssp is similar to the sp but is specific to this
transmitter delay compensation mode. The guidelines for configuring
ssp is rather vague but via some CAN test it appears for DRA76x that
putting the value same as data sampling point works.

The CAN-CIA's "Bit Time Requirements for CAN FD" paper presented at
the International CAN Conference 2013 indicates that this TDC mode is
only needed for data bit rates above 2.5 Mbps. Therefore, only enable
this mode when the data bit rate is above 2.5 Mbps.
Signed-off-by: NFranklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NFaiz Abbas <faiz_abbas@ti.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This adds Power Management deep Suspend/Resume support for Bosch M_CAN
chip.

When entering deep sleep, the clocks are gated, the interrupts are
disabled. When resuming from deep sleep, the chip needs to be
reinitialized, the clocks ungated and the interrupts enabled.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This creates a function to ungate M_CAN clocks and another to gate the
same clocks, then swaps all gating/ungating code with their respective
function.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This moves clocks gating outside of the m_can_stop function as the
m_can_start function does not (and cannot, at least in current
implementation) ungate clocks. This way, both functions can now be used
symmetrically.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

To avoid possible ECC/parity checksum errors when reading an
uninitialized buffer, the entire Message RAM is initialized when probing
the driver. This initialization is done in the same function reading the
Device Tree properties.

This patch moves the RAM initialization to a separate function so it can
be called separately from device initialization from Device Tree.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

* Added defines for TX Event FIFO Element
* Adapted ndo_start_xmit function.
  For versions >= v3.1.x it uses the TX FIFO to optimize the data
  throughput. It stores the echo skb at the same index as in the
  M_CAN's TX FIFO. The frame's message marker is set to this index.
  This message marker is received in the TX Event FIFO after
  the message was successfully transmitted. It is used to echo the
  correct echo skb back to the network stack.
* Added m_can_echo_tx_event function. It reads all received
  message markers in the TX Event FIFO and loops back the
  corresponding echo skbs.
* ISR checks for new TX Event Entry interrupt for version >= 3.1.x.
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Reviewed-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

* TX/TX Event FIFO sizes are configured for version >= v3.1.x
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

This patch adapts the initialization of the M_CAN. So it can be used
with all versions >= 3.0.x.

Changes:
* Added version element to m_can_priv structure to hold M_CAN version.
* Renamed bittiming structs for version 3.0.x
* Added new bittiming structs for version >= 3.1.x
* Function alloc_m_can_dev takes 2 new arguments. The TX FIFO size and the
  base address of the module.
* Chip configuration for CAN_CTRLMODE_LOOPBACK is changed: Enabled
  CCCR_MON bit. In combination with TEST_LBCK it activates the internal
  loopback mode. Leaving CCCR_MON '0' results in external loopback mode.
* Clocks are temporarily enabled by platform_propbe function in order to
  allow read access to the Core Release register and the Control Register.
  Registers are used to detect M_CAN version and optional Non-ISO Feature.

Initialization of M_CAN for version >= 3.1.x:
* TX FIFO of M_CAN is used to transmit frames. The driver does not need to
  stop the tx queue after each frame sent.
* Initialization of TX Event FIFO is added.
* NON-ISO is fixed for all M_CAN versions < 3.2.x. Version 3.2.x _can_ have
  the NISO (Non-ISO) bit which can switch the mode of the M_CAN to Non-ISO
  mode. This bit does not have to be writeable. Therefore it is checked.
  If it is writable Non-ISO support is added to the controllers supported
  CAN modes.

New Functions:
* Function to check the Core Release version. The read value determines the
  behaviour of the driver.
* Function to check if the NISO bit for version >= 3.2.x is implemented.
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Reviewed-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

* Updated register defines to newest M_CAN version (v3.2.1).
* Changed defines in the whole code.
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Reviewed-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

The virtual address of the device was printed. I removed it because it
leaks internal information.
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

FIFO water marks disabled because the driver doesn't handle water mark
events.
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Reviewed-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

* Disabled interrupt line 1. The driver didn't use it.
Signed-off-by: NMario Huettel <mario.huettel@gmx.net>
Tested-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

napi_complete_done() allows to opt-in for gro_flush_timeout,
added back in linux-3.19, commit 3b47d303
("net: gro: add a per device gro flush timer")

This allows for more efficient GRO aggregation without
sacrifying latencies.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As described in 'can: m_can: tag current CAN FD controllers as non-ISO'
(6cfda7fb) it is possible to define fixed configuration options by
setting the according bit in 'ctrlmode' and clear it in 'ctrlmode_supported'.
This leads to the incovenience that the fixed configuration bits can not be
passed by netlink even when they have the correct values (e.g. non-ISO, FD).

This patch fixes that issue and not only allows fixed set bit values to be set
again but now requires(!) to provide these fixed values at configuration time.
A valid CAN FD configuration consists of a nominal/arbitration bittiming, a
data bittiming and a control mode with CAN_CTRLMODE_FD set - which is now
enforced by a new can_validate() function. This fix additionally removed the
inconsistency that was prohibiting the support of 'CANFD-only' controller
drivers, like the RCar CAN FD.

For this reason a new helper can_set_static_ctrlmode() has been introduced to
provide a proper interface to handle static enabled CAN controller options.
Reported-by: NRamesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Reviewed-by: NRamesh Shanmugasundaram  <ramesh.shanmugasundaram@bp.renesas.com>
Cc: <stable@vger.kernel.org> # >= 3.18
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

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>