Add documentation of ti,sgmii-ref-clock-output-enable
which can be used to select SGMII mode type (4 or 6-wire).
Signed-off-by: Vitaly Gaiduk <vitaly.gaiduk@cloudbear.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
for applicable values. The CLK_OUT pin can also
be disabled by this property. When omitted, the
PHY's default will be left as is.
+ - ti,sgmii-ref-clock-output-enable - This denotes which
+ SGMII configuration is used (4 or 6-wire modes).
+ Some MACs work with differential SGMII clock.
+ See data manual for details.
Note: ti,min-output-impedance and ti,max-output-impedance are mutually
exclusive. When both properties are present ti,max-output-impedance