dbd86e47fd
Stefan Mätje <stefan.maetje@esd.eu> says: 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 The patch is based on the linux-can-next main branch. Changed in v11: No functional, only editorial changes due to feedback on v10. - Make lifetime of macros used for hardware timestamp calculation very short by #undef-ing them after use. - Fixed insertion order of new entry in MAINTAINERS file. Changed in v10: Most changes due to feedback by Vincent Mailhol https://lore.kernel.org/linux-can/CAMZ6RqLOAC930GNOU+pWuoi6FgYwFOuFrSyAzVjvE2fuVgy8oA@mail.gmail.com - Add support for ethtool operations by using default operations provided by the can_dev module for drivers with hardware time stamp support. - Factor out core unregistration into pci402_unregister_core(). - Factor out getting next TX fifo index into acc_tx_fifo_next(). - Stop counting alloc_can_err_skb() failures in rx_dropped statistic. - Add CAN_ERR_CNT flag in CAN error frames as needed. - Rework function acc_reset_fpga(). To clear I^2C bus enable bit is not necessary after FPGA reset. - Simplify struct acc_bmmsg_rxtxdone layout. - Additional non functional changes due to feedback by Vincent - Some spelling corrections: ESDACC -> esdACC Changes in v9: - Fix returning success error code in case of allocation failure in pci402_probe(). Changes in v8: - Rebased to 6.6-rc2 on linux-can-next branch main Changes in v7: - Numerous changes. Find the quoted with inline comments about changes below after the changes list. Stuff that I don't understand and where I have questions is marked with ????. Unfortunately I will be AFK till 28th of November. 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. previous versions: v1 - https://lore.kernel.org/linux-can/20210728203647.15240-1-Stefan.Maetje@esd.eu v2 - https://lore.kernel.org/linux-can/20210730173805.3926-1-Stefan.Maetje@esd.eu v3 - https://lore.kernel.org/linux-can/20210908164640.23243-1-stefan.maetje@esd.eu v4 - https://lore.kernel.org/linux-can/20210916172152.5127-1-stefan.maetje@esd.eu v5 - https://lore.kernel.org/linux-can/20211109155326.2608822-1-stefan.maetje@esd.eu v6 - https://lore.kernel.org/linux-can/20211201220328.3079270-1-stefan.maetje@esd.eu v7 - https://lore.kernel.org/linux-can/20221106224156.3619334-1-stefan.maetje@esd.eu v8 - https://lore.kernel.org/linux-can/20231025141635.1459606-1-stefan.maetje@esd.eu v9 - https://lore.kernel.org/linux-can/20231107184103.2802678-1-stefan.maetje@esd.eu v10 - https://lore.kernel.org/linux-can/20231120175657.4070921-1-stefan.maetje@esd.eu Link: https://lore.kernel.org/all/20231122160211.2110448-1-stefan.maetje@esd.eu Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.