doc/README.fec_mxc: add documentation
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
diff --git a/doc/README.fec_mxc b/doc/README.fec_mxc
new file mode 100644
index 0000000..72a1d59
--- /dev/null
+++ b/doc/README.fec_mxc
@@ -0,0 +1,27 @@
+U-boot config options used in fec_mxc.c
+
+CONFIG_FEC_MXC
+ Selects fec_mxc.c to be compiled into u-boot.
+
+CONFIG_MII
+ Must be defined if CONFIG_FEC_MXC is defined.
+
+CONFIG_FEC_XCV_TYPE
+ Defaults to MII100 for 100 Base-tx.
+ RGMII selects 1000 Base-tx reduced pin count interface.
+ RMII selects 100 Base-tx reduced pin count interface.
+
+CONFIG_FEC_MXC_SWAP_PACKET
+ Forced on iff MX28.
+ Swaps the bytes order of all words(4 byte units) in the packet.
+ This should not be specified by a board file. It is cpu specific.
+
+CONFIG_PHYLIB
+ fec_mxc supports PHYLIB and should be used for new boards.
+
+CONFIG_FEC_MXC_NO_ANEG
+ Relevant only if PHYLIB not used. Skips auto-negotiation restart.
+
+CONFIG_FEC_MXC_PHYADDR
+ Optional, selects the exact phy address that should be connected
+ and function fecmxc_initialize will try to initialize it.