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@xxxxxx/ *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@xxxxxxxxxx/ 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@xxxxxxxxx/ 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
