lkml.org 
[lkml]   [2021]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH 0/4] can: esd: add support for esd GmbH PCIe/402 CAN interface
Date
The purpose of this patch is to introduce a new CAN driver to support
the esd GmbH 402 family of CAN interface boards. The hardware design
is based on a CAN controller implemented in a FPGA attached to a
PCIe link.

More information on these boards can be found following the links
included in the commit message.

This patch supports all boards but will operate the CAN-FD capable
boards only in Classic-CAN mode. The CAN-FD support will be added
when the initial patch has stabilized.

The patch is reuses the previous work of my former colleague:
Link: https://lore.kernel.org/linux-can/1426592308-23817-1-git-send-email-thomas.koerper@esd.eu/

*Note*: scripts/checkpatch.pl still emits the following warnings:
- esd_402_pci-core.c:270: Possible unnecessary 'out of memory' message
This error message is there to tell the user that the DMA allocation
failed and not an allocation for normal kernel memory.
- esdacc.h:255: The irq_cnt pointer is still declared volatile and
this has a reason and is explained in detail in the header
referencing the exception noted in volatile-considered-harmful.rst.

The patch is based on the linux-can-next testing branch.

Changes in v6:
- Fixed the statistic handling of RX overrun errors and increase
net_device_stats::rx_errors instead of net_device_stats::rx_dropped.
- Added a patch to not increase rx statistics when generating a CAN
rx error message frame as suggested on the linux-can list.
- Added a patch to not not increase rx_bytes statistics for RTR frames
as suggested on the linux-can list.

The last two patches change the statistics handling from the previous
style used in other drivers to the newly suggested one.

Changes in v5:
- Added the initialization for netdev::dev_port as it is implemented
for another CAN driver. See
https://lore.kernel.org/linux-can/20211026180553.1953189-1-mailhol.vincent@wanadoo.fr/

Changes in v4:
- Fixed the build failure on ARCH=arm64 that was found by the Intel
kernel test robot. See
https://lore.kernel.org/linux-can/202109120608.7ZbQXkRh-lkp@intel.com/

Removed error monitoring code that used GCC's built-in compiler
functions for atomic access (__sync_* functions). GCC versions
after 9 (tested with "gcc-10 (Ubuntu 10.3.0-1ubuntu1~20.04)")
don't implement the intrinsic atomic as in-line code but call
"__aarch64_ldadd4_acq_rel" on arm64. This GCC support function
is not exported by the kernel and therefore the module build
post-processing fails.

Removed that code because the error monitoring never showed a
problem during the development this year.


Changes in v3:
- Rework the bus-off restart logic in acc_set_mode() and
handle_core_msg_errstatechange() to call netif_wake_queue() from the
error active event.
- Changed pci402_init_card() to allocate a variable sized array of
struct acc_core using devm_kcalloc() instead of using a fixed size
array in struct pci402_card.
- Changed handle_core_msg_txabort() to release aborted TX frames in
TX FIFO order.
- Fixed the acc_close() function to abort all pending TX request in
esdACC controller.
- Fixed counting of transmit aborts in handle_core_msg_txabort().
It is now done like in can_flush_echo_skb().
- Fixed handle_core_msg_buserr() to create error frames including the
CAN RX and TX error counters that were missing.
- Fixed acc_set_bittiming() neither to touch LOM mode setting of
esdACC controller nor to enter or leave RESET mode.
The esdACC controller is going active on the CAN bus in acc_open()
and is going inactive (RESET mode) again in acc_close().
- Rely on the automatic release of memory fetched by devm_kzalloc().
But still use devm_irq_free() explicitely to make sure that the
interrupt handler is disconnected at that point.
This avoids a possible crash in non-MSI mode due to the IRQ
triggered by another device on the same PCI IRQ line.
- Changed to use DMA map API instead of pci_*_consistent compatibility
wrappers.
- Fixed stale email references and updated copyright information.
- Removed any traces of future CAN-FD support.


Changes in v2:
- Avoid warning triggered by -Wshift-count-overflow on architectures
with 32-bit dma_addr_t.
- Fixed Makefile not to build the kernel module always. Doing this
renamed esd402_pci.c to esd_402_pci-core.c as recommended by Marc.

Stefan Mätje (4):
MAINTAINERS: add Stefan Mätje as maintainer for the esd electronics
GmbH CAN drivers
can: esd: add support for esd GmbH PCIe/402 CAN interface family
can: esd_402_pci: do not increase rx statistics when generating a CAN
rx error message frame
can: esd_402_pci: do not increase rx_bytes statistics for RTR frames

MAINTAINERS | 8 +
drivers/net/can/Kconfig | 1 +
drivers/net/can/Makefile | 1 +
drivers/net/can/esd/Kconfig | 12 +
drivers/net/can/esd/Makefile | 7 +
drivers/net/can/esd/esd_402_pci-core.c | 502 ++++++++++++++++
drivers/net/can/esd/esdacc.c | 772 +++++++++++++++++++++++++
drivers/net/can/esd/esdacc.h | 380 ++++++++++++
8 files changed, 1683 insertions(+)
create mode 100644 drivers/net/can/esd/Kconfig
create mode 100644 drivers/net/can/esd/Makefile
create mode 100644 drivers/net/can/esd/esd_402_pci-core.c
create mode 100644 drivers/net/can/esd/esdacc.c
create mode 100644 drivers/net/can/esd/esdacc.h


base-commit: f659c5c7de7982018bb961cf1f9960e60f526bdf
--
2.25.1

\
 
 \ /
  Last update: 2021-12-01 23:05    [W:0.167 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site