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

[Mark Jonas]

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