Any feedback on the driver besides the sign-off by Rob Herring on the DT-portion? Thanks, Martin > On 26.03.2018, at 18:06, kernel@xxxxxxxxxxxxxxxx wrote: > > From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx> > > This patchset adds a driver for the mcp25xxfd CanFD controller. > > Most of the features of the controller are supported by this driver release. > > The controller includes a few features that the current core Can(FD) > implementation does not support: > * Transmit Bandwidth Sharing bits > - this waits for a configurable number of syncronization bits before > atempting to transmit the next frame - for the moment controllable > via a module parameter > * SID11 with CanFD frames > - at this moment not supported by driver > * 3 transmit attempts in addition to ONE_SHOT > * transmitter delay compensation configurations > * micro second exact transmission and reception timestamps > - used internally by driver > * variable number of tx-fifos > - exposed via module parameter at this moment > > The driver has been heavily optimized so that it can handle > a 100% utilized 1MHz Can-bus (with 11 bit can frames with DLC=0) > even on less powerfull SOCs like the raspberry pi 1 without > dropping frames due to driver/spi latencies (still dropps > are observed in the can/network stack). > > To achive this the driver includes several code optimization > Two of which prefers continuous long spi transfers over multiple > small individual spi transfers of variable length. > This is an optimization that would favour spi dma transfers instead > of more expensive PIO in typical SPI controllers. > Both of them can get explicitly enabled by the use of a module parameter. > One of those is automatically used in the case of Can2.0 only bus > configurations. > > Finer details of the implementation and rational is included with > the driver code it self for future reference. > > The driver has also been tested for basic CanFD transfers with > BRS up to 5.7Mhz data bitrates - the available transceiver did > not allow for faster rates... > > The driver itself exposes lots of internal data/statistics via > debugfs. > > The driver implements a lock-less design for transmissions > making use instead of prepared spi messages submitted via spi_async > for transmission in the start_xmit_start code without requireing > an extra workqueue and the corresponding latencies. > > Note that there is an extra patch in the pipeline to implement pinctrl > but this still shows some issues, so it is not included in this patchset. > > Changelog: > V1 -> V2: new more generic name based on feedback from microchip > cleanup of code (checkpatch) > address all feedback on code > handle (HW) systemerrors in a much better/reliable way > cleanup of dt custom properties removing (most) gpio related properties > implemented GPIOLIB support as per feedback > V2 -> V3: added vendor-prefix for gpio-opendrain to dt-binding > added gpio-controller to dt-binding > added feedback by Rob Herring > waited for other feedback regarding the code > > Martin Sperl (3): > dt-binding: can: mcp25xxfd: document device tree bindings > can: mcp25xxfd: Add Microchip mcp25xxfd CAN FD driver > can: mcp25xxfd: add gpiolib support for GPIO0/1 (aka. INT0/INT1) > > .../bindings/net/can/microchip,mcp25xxfd.txt | 32 + > drivers/net/can/spi/Kconfig | 6 + > drivers/net/can/spi/Makefile | 1 + > drivers/net/can/spi/mcp25xxfd.c | 4509 ++++++++++++++++++++ > 4 files changed, 4548 insertions(+) > create mode 100644 Documentation/devicetree/bindings/net/can/microchip,mcp25xxfd.txt > create mode 100644 drivers/net/can/spi/mcp25xxfd.c > > -- > 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
