sh_eth: add support for RMIIMODE register

This register is prsent on the r8a7790 SoC.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index a753928..87af49f 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -189,6 +189,7 @@
 	[RMCR]		= 0x0258,
 	[TFUCR]		= 0x0264,
 	[RFOCR]		= 0x0268,
+	[RMIIMODE]      = 0x026c,
 	[FCFTR]		= 0x0270,
 	[TRIMD]		= 0x027c,
 };
@@ -1124,6 +1125,9 @@
 	if (ret)
 		goto out;
 
+	if (mdp->cd->rmiimode)
+		sh_eth_write(ndev, 0x1, RMIIMODE);
+
 	/* Descriptor format */
 	sh_eth_ring_format(ndev);
 	if (mdp->cd->rpadir)
diff --git a/drivers/net/ethernet/renesas/sh_eth.h b/drivers/net/ethernet/renesas/sh_eth.h
index 99995bf..da93f5c 100644
--- a/drivers/net/ethernet/renesas/sh_eth.h
+++ b/drivers/net/ethernet/renesas/sh_eth.h
@@ -60,6 +60,7 @@
 	EDOCR,
 	TFUCR,
 	RFOCR,
+	RMIIMODE,
 	FCFTR,
 	RPADIR,
 	TRIMD,
@@ -482,6 +483,7 @@
 	unsigned hw_crc:1;	/* E-DMAC have CSMR */
 	unsigned select_mii:1;	/* EtherC have RMII_MII (MII select register) */
 	unsigned shift_rd0:1;	/* shift Rx descriptor word 0 right by 16 */
+	unsigned rmiimode:1;	/* EtherC has RMIIMODE register */
 };
 
 struct sh_eth_private {