b44: use fixed PHY device if we do not find any

The ADM6996L switch and some Broadcom switches with two MII interfaces
like the BCM5325F connected to two MACs on the SoC, used on some
routers do not return a valid value when reading the PHY id register
and Linux thinks there is no PHY at all, but that is wrong.
This patch registers a fixed phy in the arch code and then searches it
when there is no other phy in the Ethernet driver code.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/mips/bcm47xx/setup.c b/arch/mips/bcm47xx/setup.c
index 1f30571..9057728 100644
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -28,6 +28,9 @@
 
 #include <linux/export.h>
 #include <linux/types.h>
+#include <linux/ethtool.h>
+#include <linux/phy.h>
+#include <linux/phy_fixed.h>
 #include <linux/ssb/ssb.h>
 #include <linux/ssb/ssb_embedded.h>
 #include <linux/bcma/bcma_soc.h>
@@ -225,6 +228,12 @@
 	bcm47xx_board_detect();
 }
 
+static struct fixed_phy_status bcm47xx_fixed_phy_status __initdata = {
+	.link	= 1,
+	.speed	= SPEED_100,
+	.duplex	= DUPLEX_FULL,
+};
+
 static int __init bcm47xx_register_bus_complete(void)
 {
 	switch (bcm47xx_bus_type) {
@@ -239,6 +248,7 @@
 		break;
 #endif
 	}
+	fixed_phy_add(PHY_POLL, 0, &bcm47xx_fixed_phy_status);
 	return 0;
 }
 device_initcall(bcm47xx_register_bus_complete);
diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c
index 839dd90..1f7b5aa 100644
--- a/drivers/net/ethernet/broadcom/b44.c
+++ b/drivers/net/ethernet/broadcom/b44.c
@@ -2233,6 +2233,7 @@
 	struct ssb_device *sdev = bp->sdev;
 	struct phy_device *phydev;
 	char bus_id[MII_BUS_ID_SIZE + 3];
+	struct ssb_sprom *sprom = &sdev->bus->sprom;
 	int err;
 
 	mii_bus = mdiobus_alloc();
@@ -2266,7 +2267,20 @@
 		goto err_out_mdiobus_irq;
 	}
 
-	snprintf(bus_id, sizeof(bus_id), PHY_ID_FMT, mii_bus->id, bp->phy_addr);
+	if (!bp->mii_bus->phy_map[bp->phy_addr] &&
+	    (sprom->boardflags_lo & (B44_BOARDFLAG_ROBO | B44_BOARDFLAG_ADM))) {
+
+		dev_info(sdev->dev,
+			 "could not find PHY at %i, use fixed one\n",
+			 bp->phy_addr);
+
+		bp->phy_addr = 0;
+		snprintf(bus_id, sizeof(bus_id), PHY_ID_FMT, "fixed-0",
+			 bp->phy_addr);
+	} else {
+		snprintf(bus_id, sizeof(bus_id), PHY_ID_FMT, mii_bus->id,
+			 bp->phy_addr);
+	}
 
 	phydev = phy_connect(bp->dev, bus_id, &b44_adjust_link,
 			     PHY_INTERFACE_MODE_MII);
diff --git a/drivers/net/ethernet/broadcom/b44.h b/drivers/net/ethernet/broadcom/b44.h
index de81639..3e9c3fc 100644
--- a/drivers/net/ethernet/broadcom/b44.h
+++ b/drivers/net/ethernet/broadcom/b44.h
@@ -345,6 +345,9 @@
 	struct u64_stats_sync	syncp;
 };
 
+#define	B44_BOARDFLAG_ROBO		0x0010  /* Board has robo switch */
+#define	B44_BOARDFLAG_ADM		0x0080  /* Board has ADMtek switch */
+
 struct ssb_device;
 
 struct b44 {