felix: Use internal MDIO regs for PHY communication

Previously we would use an external MDIO device found on the PCI bus.
Switch to using MDIO mapped in a separate BAR of the switch device.
It is much easier this way since we don't have to depend on another
driver anymore.

Obtained from: Semihalf
Sponsored by: Alstom Group

sys/dev/etherswitch/felix/felix.c

@@ -44,6 +44,8 @@ __FBSDID("$FreeBSD$");
 #include <net/if_media.h>
 #include <net/if_types.h>
 
+#include <dev/enetc/enetc_mdio.h>
+
 #include <dev/etherswitch/etherswitch.h>
 #include <dev/mii/mii.h>
 #include <dev/mii/miivar.h>
@@ -124,6 +126,10 @@ static device_method_t felix_methods[] = {
 	DEVMETHOD(etherswitch_setvgroup,	felix_setvgroup),
 	DEVMETHOD(etherswitch_getvgroup,	felix_getvgroup),
 
+	/* miibus interface */
+	DEVMETHOD(miibus_readreg,		felix_readphy),
+	DEVMETHOD(miibus_writereg,		felix_writephy),
+
 	DEVMETHOD_END
 };
 
@@ -131,15 +137,16 @@ static devclass_t felix_devclass;
 DEFINE_CLASS_0(felix, felix_driver, felix_methods,
     sizeof(struct felix_softc));
 
-DRIVER_MODULE(felix, pci, felix_driver, felix_devclass, NULL, NULL);
+DRIVER_MODULE_ORDERED(felix, pci, felix_driver, felix_devclass,
+    NULL, NULL, SI_ORDER_ANY);
+DRIVER_MODULE(miibus, felix, miibus_driver, miibus_devclass,
+    NULL, NULL);
 DRIVER_MODULE(etherswitch, felix, etherswitch_driver, etherswitch_devclass,
     NULL, NULL);
 MODULE_VERSION(felix, 1);
 MODULE_PNP_INFO("U16:vendor;U16:device;D:#", pci, felix,
     felix_pci_ids, nitems(felix_pci_ids) - 1);
 
-MODULE_DEPEND(felix, enetc_mdio, 1, 1, 1);
-
 static int
 felix_probe(device_t dev)
 {
@@ -324,7 +331,6 @@ felix_attach(device_t dev)
 	phandle_t child, ports, node;
 	int error, port, rid;
 	felix_softc_t sc;
-	device_t mdio_dev;
 	uint32_t phy_addr;
 	ssize_t size;
 
@@ -333,12 +339,21 @@ felix_attach(device_t dev)
 	sc->info.es_vlan_caps = ETHERSWITCH_VLAN_DOT1Q;
 	strlcpy(sc->info.es_name, "Felix TSN Switch", sizeof(sc->info.es_name));
 
+	rid = PCIR_BAR(FELIX_BAR_MDIO);
+	sc->mdio = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
+	    RF_ACTIVE);
+	if (sc->mdio == NULL) {
+		device_printf(dev, "Failed to allocate MDIO registers.\n");
+		return (ENXIO);
+	}
+
 	rid = PCIR_BAR(FELIX_BAR_REGS);
 	sc->regs = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
 	    RF_ACTIVE);
 	if (sc->regs == NULL) {
 		device_printf(dev, "Failed to allocate registers BAR.\n");
-		return (ENXIO);
+		error = ENXIO;
+		goto out_fail;
 	}
 
 	mtx_init(&sc->mtx, "felix lock",  NULL, MTX_DEF);
@@ -396,25 +411,9 @@ felix_attach(device_t dev)
 			goto out_fail;
 		}
 
-		node = OF_parent(node);
-		if (node <= 0) {
-			device_printf(sc->dev,
-			    "Failed to obtain MDIO node.\n");
-			error = ENXIO;
-			goto out_fail;
-		}
-
-		mdio_dev = OF_device_from_xref(node);
-		if (mdio_dev == NULL) {
-			device_printf(sc->dev,
-			    "Failed to obtain MDIO driver handle.\n");
-			error = ENXIO;
-			goto out_fail;
-		}
-
 		sc->ports[port].phyaddr = phy_addr;
 		sc->ports[port].miibus = NULL;
-		error = mii_attach(mdio_dev, &sc->ports[port].miibus, sc->ports[port].ifp,
+		error = mii_attach(dev, &sc->ports[port].miibus, sc->ports[port].ifp,
 		    felix_ifmedia_upd, felix_ifmedia_sts, BMSR_DEFCAPMASK,
 		    phy_addr, MII_OFFSET_ANY, 0);
 		if (error != 0)
@@ -447,7 +446,6 @@ static int
 felix_detach(device_t dev)
 {
 	felix_softc_t sc;
-	device_t mdio_dev;
 	int error;
 	int i;
 
@@ -468,10 +466,8 @@ felix_detach(device_t dev)
 		felix_setup(sc);
 
 	for (i = 0; i < sc->info.es_nports; i++) {
-		if (sc->ports[i].miibus != NULL) {
-			mdio_dev = device_get_parent(sc->ports[i].miibus);
-			device_delete_child(mdio_dev, sc->ports[i].miibus);
-		}
+		if (sc->ports[i].miibus != NULL)
+			device_delete_child(dev, sc->ports[i].miibus);
 		if (sc->ports[i].ifp != NULL)
 			if_free(sc->ports[i].ifp);
 		if (sc->ports[i].ifname != NULL)
@@ -482,6 +478,10 @@ felix_detach(device_t dev)
 		error = bus_release_resource(sc->dev, SYS_RES_MEMORY,
 		    rman_get_rid(sc->regs), sc->regs);
 
+	if (sc->mdio != NULL)
+		error = bus_release_resource(sc->dev, SYS_RES_MEMORY,
+		    rman_get_rid(sc->mdio), sc->mdio);
+
 	return (error);
 }
 
@@ -759,32 +759,20 @@ static int
 felix_readphy(device_t dev, int phy, int reg)
 {
 	felix_softc_t sc;
-	device_t mdio_dev;
-	int port;
 
 	sc = device_get_softc(dev);
-	port = felix_phyforport(sc, phy);
-	if (port < 0)
-		return (UINT32_MAX);	/* Can't return errors here. */
 
-	mdio_dev = device_get_parent(sc->ports[port].miibus);
-	return (MIIBUS_READREG(mdio_dev, phy, reg));
+	return (enetc_mdio_read(sc->mdio, FELIX_MDIO_BASE, phy, reg));
 }
 
 static int
 felix_writephy(device_t dev, int phy, int reg, int data)
 {
 	felix_softc_t sc;
-	device_t mdio_dev;
-	int port;
 
 	sc = device_get_softc(dev);
-	port = felix_phyforport(sc, phy);
-	if (port < 0)
-		return (ENXIO);
 
-	mdio_dev = device_get_parent(sc->ports[port].miibus);
-	return (MIIBUS_WRITEREG(mdio_dev, phy, reg, data));
+	return (enetc_mdio_write(sc->mdio, FELIX_MDIO_BASE, phy, reg, data));
 }
 
 static int

sys/dev/etherswitch/felix/felix_reg.h

@@ -31,6 +31,8 @@
 
 #define	BIT(x)						(1UL << (x))
 
+#define FELIX_MDIO_BASE					0x1C00
+
 #define	FELIX_DEVCPU_GCB_RST				0x70004
 #define	FELIX_DEVCPU_GCB_RST_EN				BIT(0)
 

sys/dev/etherswitch/felix/felix_var.h

@@ -38,6 +38,7 @@
 #define	PCI_VENDOR_FREESCALE	0x1957
 #define	FELIX_DEV_ID		0xEEF0
 
+#define	FELIX_BAR_MDIO		0
 #define	FELIX_BAR_REGS		4
 
 #define	FELIX_LOCK(_sc)			mtx_lock(&(_sc)->mtx)
@@ -92,6 +93,7 @@ struct felix_port {
 typedef struct felix_softc {
 	device_t		dev;
 	struct resource		*regs;
+	struct resource		*mdio;
 
 	etherswitch_info_t	info;
 	struct callout		tick_callout;

sys/modules/felix/Makefile

@@ -27,9 +27,10 @@
 #
 
 .PATH:	${SRCTOP}/sys/dev/etherswitch/felix
+.PATH:	${SRCTOP}/sys/dev/enetc
 
 KMOD	= felix
-SRCS	= felix.c
+SRCS	= felix.c enetc_mdio.c
 SRCS	+= bus_if.h device_if.h etherswitch_if.h miibus_if.h ofw_bus_if.h pci_if.h
 
 .include <bsd.kmod.mk>