[RFC PATCH 0/2] net: macb: Add mdio driver for accessing multiple phy devices

[Punnaiah Choudary Kalluri <punnaiah.choudary.kalluri@xilinx.com>]

This patch is to add support for the design that has multiple ethernet
mac controllers and single mdio bus connected to multiple phy devices.
i.e mdio lines are connected to any of the ethernet mac controller and
all the phy devices will be accessed using the phy maintenance interface
in that mac controller.

 ______                   _____
|      |                 |PHY0 |
| MAC0 |-----------------|     |
|______|       |         |_____|
               |           
 ______        |          _____
|      |       |         |     |
| MAC1 |       |_________|PHY1 | 
|______|                 |____ |

So, i come up with two implementations for addressing the above configuration.

Implementation 1:
 Have separate driver for mdio bus
 Create a DT node for all the PHY devices connected to the mdio bus
 This driver will share the register space of the mac controller that has
 mdio bus connected.  

Implementation 2:
 Add new property "has-mdio" and it should be 1 for the mac that has mdio bus
 connected.
 Create the mdio bus only when the has-mdio property is 1

Please review the two implementations and suggest which one is better to proceed
further. In my opinion implementation 1 will be the ideal one.

Currently i have tested the patches with single mac and single phy
configuration. I need to take care of few more cases before releasing the final patch
but before that i would like to have your opinion on the above implementations
and finalize one implementation. so that i can enhance it further.

Punnaiah Choudary Kalluri (1):
  net: macb: Add mdio driver for accessing multiple phy devices
  net: macb: Add support for single mac managing more than one phy


 drivers/net/ethernet/cadence/Makefile    |    2 +-
 drivers/net/ethernet/cadence/macb.c      |   93 +-------------
 drivers/net/ethernet/cadence/macb.h      |    3 +-
 drivers/net/ethernet/cadence/macb_mdio.c |  204 ++++++++++++++++++++++++++++++
 4 files changed, 211 insertions(+), 91 deletions(-)
 create mode 100644 drivers/net/ethernet/cadence/macb_mdio.c

-- 
1.7.4