[PATCH net-next v4 00/12] Add support for OPEN Alliance 10BASE-T1x MACPHY Serial Interface

[Parthiban Veerasooran]

This patch series contain the below updates,
- Adds support for OPEN Alliance 10BASE-T1x MACPHY Serial Interface in the
  net/ethernet/oa_tc6.c.
  Link to the spec:
  -----------------
  https://opensig.org/download/document/OPEN_Alliance_10BASET1x_MAC-PHY_Serial_Interface_V1.1.pdf

- Adds driver support for Microchip LAN8650/1 Rev.B1 10BASE-T1S MACPHY
  Ethernet driver in the net/ethernet/microchip/lan865x/lan865x.c.
  Link to the product:
  --------------------
  https://www.microchip.com/en-us/product/lan8650

Testing Details:
----------------
The driver performance was tested using iperf3 in the below two setups
separately.

Setup 1:
--------
Node 0 - Raspberry Pi 4 with LAN8650 MAC-PHY 
Node 1 - Raspberry Pi 4 with EVB-LAN8670-USB USB Stick

Setup 2:
--------
Node 0 - SAMA7G54-EK with LAN8650 MAC-PHY 
Node 1 - Raspberry Pi 4 with EVB-LAN8670-USB USB Stick

Achieved maximum of 9.4 Mbps.

Some systems like Raspberry Pi 4 need performance mode enabled to get the
proper clock speed for SPI. Refer below link for more details.

https://github.com/raspberrypi/linux/issues/3381#issuecomment-1144723750

Changes:
v2:
- Removed RFC tag.
- OA TC6 framework configured in the Kconfig and Makefile to compile as a
  module.
- Kerneldoc headers added for all the API methods exposed to MAC driver.
- Odd parity calculation logic updated from the below link,
  https://elixir.bootlin.com/linux/latest/source/lib/bch.c#L348
- Control buffer memory allocation moved to the initial function.
- struct oa_tc6 implemented as an obaque structure.
- Removed kthread for handling mac-phy interrupt instead threaded irq is
  used.
- Removed interrupt implementation for soft reset handling instead of
  that polling has been implemented.
- Registers name in the defines changed according to the specification
  document.
- Registers defines are arranged in the order of offset and followed by
  register fields.
- oa_tc6_write_register() implemented for writing a single register and
  oa_tc6_write_registers() implemented for writing multiple registers.
- oa_tc6_read_register() implemented for reading a single register and
  oa_tc6_read_registers() implemented for reading multiple registers.
- Removed DRV_VERSION macro as git hash provided by ethtool.
- Moved MDIO bus registration and PHY initialization to the OA TC6 lib.
- Replaced lan865x_set/get_link_ksettings() functions with
  phy_ethtool_ksettings_set/get() functions.
- MAC-PHY's standard capability register values checked against the
  user configured values.
- Removed unnecessary parameters validity check in various places.
- Removed MAC address configuration in the lan865x_net_open() function as
  it is done in the lan865x_probe() function already.
- Moved standard registers and proprietary vendor registers to the
  respective files.
- Added proper subject prefixes for the DT bindings.
- Moved OA specific properties to a separate DT bindings and corrected the
  types & mistakes in the DT bindings.
- Inherited OA specific DT bindings to the LAN865x specific DT bindings.
- Removed sparse warnings in all the places.
- Used net_err_ratelimited() for printing the error messages.
- oa_tc6_process_rx_chunks() function and the content of oa_tc6_handler()
  function are split into small functions.
- Used proper macros provided by network layer for calculating the
  MAX_ETH_LEN.
- Return value of netif_rx() function handled properly.
- Removed unnecessary NULL initialization of skb in the
  oa_tc6_rx_eth_ready() function removed.
- Local variables declaration ordered in reverse xmas tree notation.

v3:
- Completely redesigned all the patches.
- Control and data interface patches are divided into multiple small
  patches.
- Device driver APIs added in the oa-tc6-framework.rst file.
- Code readability improved in all the patches.
- Defined macros wherever is possible.
- Changed RESETC to STATUS0_RESETC for improving the readability.
- Removed OA specific DT bindings.
- Used default configurations defined in the OA spec.
- All variables are named properly as per OA spec for more redability.
- Bigger functions are split into multiple smaller functions.
- DT binding check is done.
- Phy mask is removed in phy scanning.
- Used NET_RX_DROP to compare the rx packet submission status.
- Indentation in the Kconfig file corrected.
- Removed CONFIG_OF and CONFIG_ACPI ifdefs.
- Removed MODULE_ALIAS().

v4:
- Fixed indentation in oa-tc6-framework.rst file.
- Replaced ENODEV error code with EPROTO in the
  oa_tc6_check_ctrl_write_reply and oa_tc6_check_ctrl_read_reply()
  functions.
- Renamed oa_tc6_read_sw_reset_status() function as
  oa_tc6_read_status0().
- Changed software reset polling delay as 1ms and polling timeout as 1s.
- Implemented clause 45 registers direct access.
- Replaced ENODEV error code with ENOMEM in the
  oa_tc6_mdiobus_register() function.
- Changed transmit skbs queue size as 2.
- Added skb_linearize() function to convert contiguous packet data.
- Checked kthread_should_stop() in the oa_tc6_spi_thread_handler()
  function before proceeding for the oa_tc6_try_spi_transfer().
- Removed netdev_err() print in the oa_tc6_allocate_rx_skb() function.
- Added spi-peripheral-props reference in the dt-bindings.
- Changed the fallback order in the dt-bindings.
- Replaced netif_start_queue() with netif_wake_queue().
- Empty data transfer performed in the oa_tc6_init() function to clear
  the reset complete interrupt.
- ZARFE bit in the CONFIG0 register is set to 1 to avoid lan865x halt
  based on the recommendation in the lan865x errata.

Parthiban Veerasooran (12):
  Documentation: networking: add OPEN Alliance 10BASE-T1x MAC-PHY serial
    interface
  net: ethernet: oa_tc6: implement register write operation
  net: ethernet: oa_tc6: implement register read operation
  net: ethernet: oa_tc6: implement software reset
  net: ethernet: oa_tc6: implement error interrupts unmasking
  net: ethernet: oa_tc6: implement internal PHY initialization
  net: ethernet: oa_tc6: enable open alliance tc6 data communication
  net: ethernet: oa_tc6: implement transmit path to transfer tx ethernet
    frames
  net: ethernet: oa_tc6: implement receive path to receive rx ethernet
    frames
  net: ethernet: oa_tc6: implement mac-phy interrupt
  microchip: lan865x: add driver support for Microchip's LAN865X MAC-PHY
  dt-bindings: net: add Microchip's LAN865X 10BASE-T1S MACPHY

 .../bindings/net/microchip,lan865x.yaml       |   80 +
 Documentation/networking/oa-tc6-framework.rst |  491 ++++++
 MAINTAINERS                                   |   15 +
 drivers/net/ethernet/Kconfig                  |   11 +
 drivers/net/ethernet/Makefile                 |    1 +
 drivers/net/ethernet/microchip/Kconfig        |    1 +
 drivers/net/ethernet/microchip/Makefile       |    1 +
 .../net/ethernet/microchip/lan865x/Kconfig    |   19 +
 .../net/ethernet/microchip/lan865x/Makefile   |    6 +
 .../net/ethernet/microchip/lan865x/lan865x.c  |  384 +++++
 drivers/net/ethernet/oa_tc6.c                 | 1321 +++++++++++++++++
 drivers/net/phy/microchip_t1s.c               |   30 +
 include/linux/oa_tc6.h                        |   23 +
 include/uapi/linux/mdio.h                     |    1 +
 14 files changed, 2384 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/microchip,lan865x.yaml
 create mode 100644 Documentation/networking/oa-tc6-framework.rst
 create mode 100644 drivers/net/ethernet/microchip/lan865x/Kconfig
 create mode 100644 drivers/net/ethernet/microchip/lan865x/Makefile
 create mode 100644 drivers/net/ethernet/microchip/lan865x/lan865x.c
 create mode 100644 drivers/net/ethernet/oa_tc6.c
 create mode 100644 include/linux/oa_tc6.h

-- 
2.34.1