On 11/29/07, Ulf Samuelsson ulf@atmel.com wrote:
tor 2007-11-29 klockan 19:51 +0100 skrev Guennadi Liakhovetski:
Hi,
- Does it make sense at all to define CONFIG_RMII without defining
CONFIG_MII? The question is meant not really theoretical as in what meaning RMII has, rather how the macro CONFIG_RMII is supposed to be
used?
For example, tests like
I think that if you use an Ethernet and need to differentiate between MII and RMII they should be mutually exclusive. You either define CONFIG_RMII OR CONFIG_MII but not both. If you have a PHY on the chip, then you do not define any of the two. MII uses more pins and maybe different pins, so a port for a CPU should differentiate.
I'm a little late to this, but I feel I should make sure people are aware that CONFIG_MII and CONFIG_RMII are not, in this case, two different options for the same concept. CONFIG_MII is the option you enable to allow MII Management operations to be done. It should *probably* be called CONFIG_MDIO. You'll see this problem all over the place. MII is the name for the data interface between a PHY and a 10/100 ethernet controller. MDIO is the management interface for MII-compliant PHYs. But it's frequently called the MII Management interface.
RMII is a different data interface for PHYs, but it uses the same MDIO interface.
So I believe if you see: #if defined(CONFIG_MII) && defined(CONFIG_RMII), what you are seeing is a check for global mii management capability as well as board-specific reduced interface selection.
As to whether one or more of these definitions is poorly named, I leave that as an exercise for the reader. ;)
Andy