[PATCH v2 0/5] can: enable multi-queue for SocketCAN devices

From: Mark Jonas
Date: Wed Jun 13 2018 - 10:38:18 EST


Changes in v2:
- use GPIO descriptor API
- make error handling pattern consistent
- use more kernel helper macros and functions
- fix coding style issues
- remove superfluous subsystem name from filename

---

Upon request by Marc Kleine-Budde this patch series does not only
contain our patch to enable enable multi-queue for SocketCAN devices
but also a driver (Companion driver suite) which makes active use of
this feature.

The driver suite implements
- two CAN interfaces
- one generic command interfaces
and offers a SocketCAN as well as a char device interface. The
SocketCAN interface supports multi-queue.

The functionality bases on an external peripheral chip named Companion.
It offers two CAN interfaces, each has 8 prioritized transmit FIFOs as
well as one receive FIFO. Besides CAN, undisclosed additional functions
can be accessed through the char device.

A standard SPI interface with two additional lines for flow control is
used. The Companion chip is the SPI slave.

The driver suite consists of three separate drivers. The following
diagram illustrates the dependencies in layers.

/dev/companion SocketCAN User Space
-------------------------------------------------------------------
+----------------+ +---------------+
| companion-char | | companion-can |
+----------------+ +---------------+
+----------------------------------+
| companion-spi |
+----------------------------------+
+----------------------------------+
| standard SPI subsystem |
+----------------------------------+ Linux Kernel
-------------------------------------------------------------------
| | | | | | Hardware
CS-+ | | | | +-BUSY
CLK--+ | | +---REQUEST
MOSI---+ |
MISO-----+

companion-spi
core.c: handles SPI, sysfs entry and interface to upper layer
protocol-manager.c: handles protocol with the SPI HW
queue-manager.c: handles buffering and packets scheduling

companion-can
makes use of multi-queue support and allows to use tc to configure
the queuing discipline (e.g. mqprio). Together with the SO_PRIORITY
socket option this allows to specify the FIFO a CAN frame shall be
sent to.

companion-char
handles messages to other undisclosed functionality beyond CAN.

Zhu Yi (5):
can: enable multi-queue for SocketCAN devices
spi: implement companion-spi driver
char: implement companion-char driver
can: implement companion-can driver
spi,can,char: add companion DT binding documentation

.../devicetree/bindings/spi/bosch,companion.txt | 82 ++
drivers/char/Kconfig | 7 +
drivers/char/Makefile | 3 +
drivers/char/companion.c | 360 ++++++
drivers/net/can/Kconfig | 8 +
drivers/net/can/Makefile | 2 +
drivers/net/can/companion.c | 693 ++++++++++++
drivers/net/can/dev.c | 8 +-
drivers/spi/Kconfig | 2 +
drivers/spi/Makefile | 2 +
drivers/spi/companion/Kconfig | 5 +
drivers/spi/companion/Makefile | 2 +
drivers/spi/companion/core.c | 1185 ++++++++++++++++++++
drivers/spi/companion/protocol-manager.c | 1032 +++++++++++++++++
drivers/spi/companion/protocol-manager.h | 341 ++++++
drivers/spi/companion/protocol.h | 273 +++++
drivers/spi/companion/queue-manager.c | 144 +++
drivers/spi/companion/queue-manager.h | 245 ++++
include/linux/can/dev.h | 7 +-
include/linux/companion.h | 259 +++++
20 files changed, 4656 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/bosch,companion.txt
create mode 100644 drivers/char/companion.c
create mode 100644 drivers/net/can/companion.c
create mode 100644 drivers/spi/companion/Kconfig
create mode 100644 drivers/spi/companion/Makefile
create mode 100644 drivers/spi/companion/core.c
create mode 100644 drivers/spi/companion/protocol-manager.c
create mode 100644 drivers/spi/companion/protocol-manager.h
create mode 100644 drivers/spi/companion/protocol.h
create mode 100644 drivers/spi/companion/queue-manager.c
create mode 100644 drivers/spi/companion/queue-manager.h
create mode 100644 include/linux/companion.h

--
2.7.4