RFC Support for PHY test modes

Hi all,

This patch series adds support for specifying PHY test modes through ethtool and paves the ground for adding support for more complex test modes that might require data to be exchanged between user and kernel space.

As an example, patches are included to add support for the IEEE electrical test modes for 100BaseT2 and 1000BaseT. Those do not require data to be passed back and forth.

I believe the infrastructure to be usable enough to add support for other things like:

- cable diagnostics
- pattern generator/waveform generator with specific pattern being indicated for instance

Questions for Andrew, and others:

- there could be room for adding additional ETH_TEST_FL_* values in order to help determine how the test should be running
- some of these tests can be disruptive to connectivity, the minimum we could do is stop the PHY state machine and restart it when "normal" is used to exit those test modes

Comments welcome!

Example:

# ethtool --get-phy-tests gphy
PHY tests gphy:
     normal (Test data: No)
     100baseT2-tx-waveform (Test data: No)
     100baseT2-tx-jitter (Test data: No)
     100baseT2-tx-idle (Test data: No)
     1000baseT-tx-waveform (Test data: No)
     1000baseT-tx-jitter-master (Test data: No)
     1000baseT-tx-jitter-slave (Test data: No)
     1000BaseT-tx-distorsion (Test data: No)
# ethtool --set-phy-test gphy 100baseT2-tx-waveform
# [   65.262513] brcm-sf2 f0b00000.ethernet_switch gphy: Link is Down

Florian Fainelli (5):
net: phy: Pass stringset argument to ethtool operations
net: ethtool: Add UAPI for PHY test modes
net: ethtool: Add plumbing to get/set PHY test modes
net: phy: Add support for IEEE standard test modes
net: phy: broadcom: Add support for PHY test modes

 drivers/net/dsa/b53/b53_common.c |   4 +-
 drivers/net/phy/Kconfig          |   6 ++
 drivers/net/phy/Makefile         |   4 +-
 drivers/net/phy/bcm-phy-lib.c    |  21 ++++--
 drivers/net/phy/bcm-phy-lib.h    |   4 +-
 drivers/net/phy/bcm7xxx.c        |   9 ++-
 drivers/net/phy/broadcom.c       |   6 +-
 drivers/net/phy/marvell.c        |  11 ++-
 drivers/net/phy/micrel.c         |  11 ++-
 drivers/net/phy/phy-tests.c      | 159 +++++++++++++++++++++++++++++++++++++++
 drivers/net/phy/smsc.c           |  10 ++-
 include/linux/phy.h              |  99 +++++++++++++++++++++---
 include/net/dsa.h                |   4 +-
 include/uapi/linux/ethtool.h     |  23 ++++++
 net/core/ethtool.c               |  86 +++++++++++++++++++--
 net/dsa/master.c                 |   9 ++-
 net/dsa/port.c                   |   8 +-
 17 files changed, 427 insertions(+), 47 deletions(-)
 create mode 100644 drivers/net/phy/phy-tests.c

2.14.1