Add support for the National Semiconductor DP83815 fast ethernet

controller chip. This chip is currently being used on the NetGear
FA312-TX adapter, which I guess is a replacement for the FA310-TX
(PNIC-based).

I added support for this chip by modifying the sis driver since
the SiS 900 and the NS DP83815 have almost the same programming
interface (the RX filter programming and PHY access methods are
different, but the general configuration, DMA scheme and register
layout are identical).

I would have had this done a lot sooner, but getting the damn MAC
address out of the EEPROM proved to be more complicated than expected.

2 files changed, 229 insertions, 21 deletions

diff --git a/sys/pci/if_sis.c b/sys/pci/if_sis.c
index b954433..8410a7f 100644
--- a/sys/pci/if_sis.c
+++ b/sys/pci/if_sis.c
@@ -106,6 +106,7 @@ static const char rcsid[] =
 static struct sis_type sis_devs[] = {
 	{ SIS_VENDORID, SIS_DEVICEID_900, "SiS 900 10/100BaseTX" },
 	{ SIS_VENDORID, SIS_DEVICEID_7016, "SiS 7016 10/100BaseTX" },
+	{ NS_VENDORID, NS_DEVICEID_DP83815, "NatSemi DP83815 10/100BaseTX" },
 	{ 0, 0, NULL }
 };
 
@@ -132,6 +133,7 @@ static void sis_shutdown		__P((device_t));
 static int sis_ifmedia_upd	__P((struct ifnet *));
 static void sis_ifmedia_sts	__P((struct ifnet *, struct ifmediareq *));
 
+static u_int16_t sis_reverse	__P((u_int16_t));
 static void sis_delay		__P((struct sis_softc *));
 static void sis_eeprom_idle	__P((struct sis_softc *));
 static void sis_eeprom_putbyte	__P((struct sis_softc *, int));
@@ -142,8 +144,9 @@ static int sis_miibus_readreg	__P((device_t, int, int));
 static int sis_miibus_writereg	__P((device_t, int, int, int));
 static void sis_miibus_statchg	__P((device_t));
 
-static void sis_setmulti	__P((struct sis_softc *));
-static u_int32_t sis_calchash	__P((caddr_t));
+static void sis_setmulti_sis	__P((struct sis_softc *));
+static void sis_setmulti_ns	__P((struct sis_softc *));
+static u_int32_t sis_crc	__P((struct sis_softc *, caddr_t));
 static void sis_reset		__P((struct sis_softc *));
 static int sis_list_rx_init	__P((struct sis_softc *));
 static int sis_list_tx_init	__P((struct sis_softc *));
@@ -200,6 +203,21 @@ DRIVER_MODULE(miibus, sis, miibus_driver, miibus_devclass, 0, 0);
 #define SIO_CLR(x)					\
 	CSR_WRITE_4(sc, SIS_EECTL, CSR_READ_4(sc, SIS_EECTL) & ~x)
 
+/*
+ * Routine to reverse the bits in a word. Stolen almost
+ * verbatim from /usr/games/fortune.
+ */
+static u_int16_t sis_reverse(n)
+	u_int16_t		n;
+{
+	n = ((n >>  1) & 0x5555) | ((n <<  1) & 0xaaaa);
+	n = ((n >>  2) & 0x3333) | ((n <<  2) & 0xcccc);
+	n = ((n >>  4) & 0x0f0f) | ((n <<  4) & 0xf0f0);
+	n = ((n >>  8) & 0x00ff) | ((n <<  8) & 0xff00);
+
+	return(n);
+}
+
 static void sis_delay(sc)
 	struct sis_softc	*sc;
 {
@@ -283,9 +301,9 @@ static void sis_eeprom_getword(sc, addr, dest)
 
 	/* Enter EEPROM access mode. */
 	sis_delay(sc);
-	SIO_SET(SIS_EECTL_CSEL);
+	SIO_CLR(SIS_EECTL_CLK);
 	sis_delay(sc);
-	SIO_SET(SIS_EECTL_CLK);
+	SIO_SET(SIS_EECTL_CSEL);
 	sis_delay(sc);
 
 	/*
@@ -344,10 +362,29 @@ static int sis_miibus_readreg(dev, phy, reg)
 	int			phy, reg;
 {
 	struct sis_softc	*sc;
-	int			i, val;
+	int			i, val = 0;
 
 	sc = device_get_softc(dev);
 
+	if (sc->sis_type == SIS_TYPE_83815) {
+		if (phy != 0)
+			return(0);
+		/*
+		 * The NatSemi chip can take a while after
+		 * a reset to come ready, during which the BMSR
+		 * returns a value of 0. This is *never* supposed
+		 * to happen: some of the BMSR bits are meant to
+		 * be hardwired in the on position, and this can
+		 * confuse the miibus code a bit during the probe
+		 * and attach phase. So we make an effort to check
+		 * for this condition and wait for it to clear.
+		 */
+		if (!CSR_READ_4(sc, NS_BMSR))
+			DELAY(1000);
+		val = CSR_READ_4(sc, NS_BMCR + (reg * 4));
+		return(val);
+	}
+
 	if (sc->sis_type == SIS_TYPE_900 && phy != 0)
 		return(0);
 
@@ -381,6 +418,16 @@ static int sis_miibus_writereg(dev, phy, reg, data)
 
 	sc = device_get_softc(dev);
 
+	if (sc->sis_type == SIS_TYPE_83815) {
+		if (phy != 0)
+			return(0);
+		CSR_WRITE_4(sc, NS_BMCR + (reg * 4), data);
+		return(0);
+	}
+
+	if (sc->sis_type == SIS_TYPE_900 && phy != 0)
+		return(0);
+
 	if (sc->sis_type == SIS_TYPE_900 && phy != 0)
 		return(0);
 
@@ -421,7 +468,8 @@ static void sis_miibus_statchg(dev)
 	return;
 }
 
-static u_int32_t sis_calchash(addr)
+static u_int32_t sis_crc(sc, addr)
+	struct sis_softc	*sc;
 	caddr_t			addr;
 {
 	u_int32_t		crc, carry; 
@@ -442,11 +490,68 @@ static u_int32_t sis_calchash(addr)
 		}
 	}
 
-	/* return the filter bit position */
+	/*
+	 * return the filter bit position
+	 *
+	 * The NatSemi chip has a 512-bit filter, which is
+	 * different than the SiS, so we special-case it.
+	 */
+	if (sc->sis_type == SIS_TYPE_83815)
+		return((crc >> 23) & 0x1FF);
+
 	return((crc >> 25) & 0x0000007F);
 }
 
-static void sis_setmulti(sc)
+static void sis_setmulti_ns(sc)
+	struct sis_softc	*sc;
+{
+	struct ifnet		*ifp;
+	struct ifmultiaddr	*ifma;
+	u_int32_t		h = 0, i, filtsave;
+	int			bit, index;
+
+	ifp = &sc->arpcom.ac_if;
+
+	if (ifp->if_flags & IFF_ALLMULTI || ifp->if_flags & IFF_PROMISC) {
+		SIS_CLRBIT(sc, SIS_RXFILT_CTL, NS_RXFILTCTL_MCHASH);
+		SIS_SETBIT(sc, SIS_RXFILT_CTL, SIS_RXFILTCTL_ALLMULTI);
+		return;
+	}
+
+	/*
+	 * We have to explicitly enable the multicast hash table
+	 * on the NatSemi chip if we want to use it, which we do.
+	 */
+	SIS_SETBIT(sc, SIS_RXFILT_CTL, NS_RXFILTCTL_MCHASH);
+	SIS_CLRBIT(sc, SIS_RXFILT_CTL, SIS_RXFILTCTL_ALLMULTI);
+
+	filtsave = CSR_READ_4(sc, SIS_RXFILT_CTL);
+
+	/* first, zot all the existing hash bits */
+	for (i = 0; i < 32; i++) {
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, NS_FILTADDR_FMEM_LO + (i*2));
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA, 0);
+	}
+
+	for (ifma = ifp->if_multiaddrs.lh_first; ifma != NULL;
+	    ifma = ifma->ifma_link.le_next) {
+		if (ifma->ifma_addr->sa_family != AF_LINK)
+			continue;
+		h = sis_crc(sc, LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
+		index = h >> 3;
+		bit = h & 0x1F;
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, NS_FILTADDR_FMEM_LO + index);
+		if (bit > 0xF)
+			bit -= 0x10;
+		SIS_SETBIT(sc, SIS_RXFILT_DATA, (1 << bit));
+	}
+
+	CSR_WRITE_4(sc, SIS_RXFILT_CTL, filtsave);
+
+	return;
+}
+
+static void sis_setmulti_sis(sc)
 	struct sis_softc	*sc;
 {
 	struct ifnet		*ifp;
@@ -475,7 +580,7 @@ static void sis_setmulti(sc)
 	    ifma = ifma->ifma_link.le_next) {
 		if (ifma->ifma_addr->sa_family != AF_LINK)
 			continue;
-		h = sis_calchash(LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
+		h = sis_crc(sc, LLADDR((struct sockaddr_dl *)ifma->ifma_addr));
 		CSR_WRITE_4(sc, SIS_RXFILT_CTL, (4 + (h >> 4)) << 16);
 		SIS_SETBIT(sc, SIS_RXFILT_DATA, (1 << (h & 0xF)));
 	}
@@ -552,6 +657,8 @@ static int sis_attach(dev)
 		sc->sis_type = SIS_TYPE_900;
 	if (pci_get_device(dev) == SIS_DEVICEID_7016)
 		sc->sis_type = SIS_TYPE_7016;
+	if (pci_get_vendor(dev) == NS_VENDORID)
+		sc->sis_type = SIS_TYPE_83815;
 
 	/*
 	 * Handle power management nonsense.
@@ -645,7 +752,47 @@ static int sis_attach(dev)
 	/*
 	 * Get station address from the EEPROM.
 	 */
-	sis_read_eeprom(sc, (caddr_t)&eaddr, SIS_EE_NODEADDR, 3, 0);
+	switch (pci_get_vendor(dev)) {
+	case NS_VENDORID:
+		/*
+		 * Reading the MAC address out of the EEPROM on
+		 * the NatSemi chip takes a bit more work than
+		 * you'd expect. The address spans 4 16-bit words,
+		 * with the first word containing only a single bit.
+		 * You have to shift everything over one bit to
+		 * get it aligned properly. Also, the bits are
+		 * stored backwards (the LSB is really the MSB,
+		 * and so on) so you have to reverse them in order
+		 * to get the MAC address into the form we want.
+		 * Why? Who the hell knows.
+		 */
+		{
+			u_int16_t		tmp[4];
+
+			sis_read_eeprom(sc, (caddr_t)&tmp,
+			    NS_EE_NODEADDR, 4, 0);
+
+			/* Shift everything over one bit. */
+			tmp[3] = tmp[3] >> 1;
+			tmp[3] |= tmp[2] >> 15;
+			tmp[2] = tmp[2] >> 1;
+			tmp[2] |= tmp[1] >> 15;
+			tmp[1] = tmp[1] >> 1;
+			tmp[1] |= tmp[0] >> 15;
+
+			/* Now reverse all the bits. */
+			tmp[3] = sis_reverse(tmp[3]);
+			tmp[2] = sis_reverse(tmp[2]);
+			tmp[1] = sis_reverse(tmp[1]);
+
+			bcopy((char *)&tmp[1], eaddr, ETHER_ADDR_LEN);
+		}
+		break;
+	case SIS_VENDORID:
+	default:
+		sis_read_eeprom(sc, (caddr_t)&eaddr, SIS_EE_NODEADDR, 3, 0);
+		break;
+	}
 
 	/*
 	 * A SiS chip was detected. Inform the world.
@@ -1183,15 +1330,27 @@ static void sis_init(xsc)
 	mii = device_get_softc(sc->sis_miibus);
 
 	/* Set MAC address */
-	CSR_WRITE_4(sc, SIS_RXFILT_CTL, SIS_FILTADDR_PAR0);
-	CSR_WRITE_4(sc, SIS_RXFILT_DATA,
-	    ((u_int16_t *)sc->arpcom.ac_enaddr)[0]);
-	CSR_WRITE_4(sc, SIS_RXFILT_CTL, SIS_FILTADDR_PAR1);
-	CSR_WRITE_4(sc, SIS_RXFILT_DATA,
-	    ((u_int16_t *)sc->arpcom.ac_enaddr)[1]);
-	CSR_WRITE_4(sc, SIS_RXFILT_CTL, SIS_FILTADDR_PAR2);
-	CSR_WRITE_4(sc, SIS_RXFILT_DATA,
-	    ((u_int16_t *)sc->arpcom.ac_enaddr)[2]);
+	if (sc->sis_type == SIS_TYPE_83815) {
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, NS_FILTADDR_PAR0);
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA,
+		    ((u_int16_t *)sc->arpcom.ac_enaddr)[0]);
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, NS_FILTADDR_PAR1);
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA,
+		    ((u_int16_t *)sc->arpcom.ac_enaddr)[1]);
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, NS_FILTADDR_PAR2);
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA,
+		    ((u_int16_t *)sc->arpcom.ac_enaddr)[2]);
+	} else {
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, SIS_FILTADDR_PAR0);
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA,
+		    ((u_int16_t *)sc->arpcom.ac_enaddr)[0]);
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, SIS_FILTADDR_PAR1);
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA,
+		    ((u_int16_t *)sc->arpcom.ac_enaddr)[1]);
+		CSR_WRITE_4(sc, SIS_RXFILT_CTL, SIS_FILTADDR_PAR2);
+		CSR_WRITE_4(sc, SIS_RXFILT_DATA,
+		    ((u_int16_t *)sc->arpcom.ac_enaddr)[2]);
+	}
 
 	/* Init circular RX list. */
 	if (sis_list_rx_init(sc) == ENOBUFS) {
@@ -1207,6 +1366,17 @@ static void sis_init(xsc)
 	 */
 	sis_list_tx_init(sc);
 
+	/*
+	 * For the NatSemi chip, we have to explicitly enable the
+	 * reception of ARP frames, as well as turn on the 'perfect
+	 * match' filter where we store the station address, otherwise
+	 * we won't receive unicasts meant for this host.
+	 */
+	if (sc->sis_type == SIS_TYPE_83815) {
+		SIS_SETBIT(sc, SIS_RXFILT_CTL, NS_RXFILTCTL_ARP);
+		SIS_SETBIT(sc, SIS_RXFILT_CTL, NS_RXFILTCTL_PERFECT);
+	}
+
 	 /* If we want promiscuous mode, set the allframes bit. */
 	if (ifp->if_flags & IFF_PROMISC) {
 		SIS_SETBIT(sc, SIS_RXFILT_CTL, SIS_RXFILTCTL_ALLPHYS);
@@ -1226,7 +1396,10 @@ static void sis_init(xsc)
 	/*
 	 * Load the multicast filter.
 	 */
-	sis_setmulti(sc);
+	if (sc->sis_type == SIS_TYPE_83815)
+		sis_setmulti_ns(sc);
+	else
+		sis_setmulti_sis(sc);
 
 	/* Turn the receive filter on */
 	SIS_SETBIT(sc, SIS_RXFILT_CTL, SIS_RXFILTCTL_ENABLE);
@@ -1331,7 +1504,10 @@ static int sis_ioctl(ifp, command, data)
 		break;
 	case SIOCADDMULTI:
 	case SIOCDELMULTI:
-		sis_setmulti(sc);
+		if (sc->sis_type == SIS_TYPE_83815)
+			sis_setmulti_ns(sc);
+		else
+			sis_setmulti_sis(sc);
 		error = 0;
 		break;
 	case SIOCGIFMEDIA:
diff --git a/sys/pci/if_sisreg.h b/sys/pci/if_sisreg.h
index cef3a52..a74dc3b 100644
--- a/sys/pci/if_sisreg.h
+++ b/sys/pci/if_sisreg.h
@@ -74,6 +74,16 @@
 #define SIS_TIMEUNIT		0xA4
 #define SIS_GPIO		0xB8
 
+/* NS DP83815 registers */
+#define NS_BMCR			0x80
+#define NS_BMSR			0x84
+#define NS_PHYIDR1		0x88
+#define NS_PHYIDR2		0x8C
+#define NS_ANAR			0x90
+#define NS_ANLPAR		0x94
+#define NS_ANER			0x98
+#define NS_ANNPTR		0x9C
+
 #define SIS_CSR_TX_ENABLE	0x00000001
 #define SIS_CSR_TX_DISABLE	0x00000002
 #define SIS_CSR_RX_ENABLE	0x00000004
@@ -100,6 +110,7 @@
 #define SIS_EECMD_ERASE		0x1c0
 
 #define SIS_EE_NODEADDR		0x8
+#define NS_EE_NODEADDR		0x6
 
 #define SIS_PCICTL_SRAMADDR	0x0000001F
 #define SIS_PCICTL_RAMTSTENB	0x00000020
@@ -220,6 +231,9 @@
 	(SIS_RXCFG_DRAIN(64)|SIS_RXDMA_256BYTES)
 
 #define SIS_RXFILTCTL_ADDR	0x000F0000
+#define NS_RXFILTCTL_MCHASH	0x00200000
+#define NS_RXFILTCTL_ARP	0x00400000
+#define NS_RXFILTCTL_PERFECT	0x08000000
 #define SIS_RXFILTCTL_ALLPHYS	0x10000000
 #define SIS_RXFILTCTL_ALLMULTI	0x20000000
 #define SIS_RXFILTCTL_BROAD	0x40000000
@@ -237,6 +251,13 @@
 #define SIS_FILTADDR_MAR6	0x000A0000
 #define SIS_FILTADDR_MAR7	0x000B0000
 
+#define NS_FILTADDR_PAR0	0x00000000
+#define NS_FILTADDR_PAR1	0x00000002
+#define NS_FILTADDR_PAR2	0x00000004
+
+#define NS_FILTADDR_FMEM_LO	0x00000200
+#define NS_FILTADDR_FMEM_HI	0x000003FE
+
 /*
  * DMA descriptor structures. The first part of the descriptor
  * is the hardware descriptor format, which is just three longwords.
@@ -322,6 +343,16 @@ struct sis_ring_data {
 #define SIS_DEVICEID_900	0x0900
 #define SIS_DEVICEID_7016	0x7016
 
+/*
+ * NatSemi vendor ID
+ */
+#define NS_VENDORID		0x100B
+
+/*
+ * DP83815 device ID
+ */
+#define NS_DEVICEID_DP83815	0x0020
+
 struct sis_type {
 	u_int16_t		sis_vid;
 	u_int16_t		sis_did;
@@ -330,6 +361,7 @@ struct sis_type {
 
 #define SIS_TYPE_900	1
 #define SIS_TYPE_7016	2
+#define SIS_TYPE_83815	3
 
 struct sis_softc {
 	struct arpcom		arpcom;		/* interface info */