intpm: add support for smbus controller found in AMD SB700

According to the specifications AMD/ATI SMBus controller is very
similar to SMBus controller found in PIIX4.
Some notable differences:
 o different bit for enabling/signalling regular interrupt mode
 o in practice seems to support only polling mode
Thus, intpm driver is modified to support polling-only mode
and to recognize SB700 PCI ID and differences.

Tested on:	SB700 and PIIX4E platforms
Reviewed by:	jhb
MFC after:	2 weeks
X-Perhaps-ToDo:	rename the driver to reflect its function
		and supported hardware

2 files changed, 43 insertions, 13 deletions

diff --git a/sys/pci/intpm.c b/sys/pci/intpm.c
index 63eb4c4..13404c8 100644
--- a/sys/pci/intpm.c
+++ b/sys/pci/intpm.c
@@ -53,6 +53,8 @@ struct intsmb_softc {
 	void			*irq_hand;
 	device_t		smbus;
 	int			isbusy;
+	int			cfg_irq9;
+	int			poll;
 	struct mtx		lock;
 };
 
@@ -96,6 +98,10 @@ intsmb_probe(device_t dev)
 #endif
 		device_set_desc(dev, "Intel PIIX4 SMBUS Interface");
 		break;
+	case 0x43851002:
+		device_set_desc(dev, "AMD SB600/700/710/750 SMBus Controller");
+		/* XXX Maybe force polling right here? */
+		break;
 	default:
 		return (ENXIO);
 	}
@@ -108,12 +114,24 @@ intsmb_attach(device_t dev)
 {
 	struct intsmb_softc *sc = device_get_softc(dev);
 	int error, rid, value;
+	int intr;
 	char *str;
 
 	sc->dev = dev;
 
 	mtx_init(&sc->lock, device_get_nameunit(dev), "intsmb", MTX_DEF);
 
+	sc->cfg_irq9 = 0;
+#ifndef NO_CHANGE_PCICONF
+	switch (pci_get_devid(dev)) {
+	case 0x71138086:	/* Intel 82371AB */
+	case 0x719b8086:	/* Intel 82443MX */
+		/* Changing configuration is allowed. */
+		sc->cfg_irq9 = 1;
+		break;
+	}
+#endif
+
 	rid = PCI_BASE_ADDR_SMB;
 	sc->io_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
 	    RF_ACTIVE);
@@ -123,27 +141,36 @@ intsmb_attach(device_t dev)
 		goto fail;
 	}
 
-#ifndef NO_CHANGE_PCICONF
-	pci_write_config(dev, PCIR_INTLINE, 0x9, 1);
-	pci_write_config(dev, PCI_HST_CFG_SMB,
-	    PCI_INTR_SMB_IRQ9 | PCI_INTR_SMB_ENABLE, 1);
-#endif
+	if (sc->cfg_irq9) {
+		pci_write_config(dev, PCIR_INTLINE, 0x9, 1);
+		pci_write_config(dev, PCI_HST_CFG_SMB,
+		    PCI_INTR_SMB_IRQ9 | PCI_INTR_SMB_ENABLE, 1);
+	}
 	value = pci_read_config(dev, PCI_HST_CFG_SMB, 1);
-	switch (value & 0xe) {
+	sc->poll = (value & PCI_INTR_SMB_ENABLE) == 0;
+	intr = value & PCI_INTR_SMB_MASK;
+	switch (intr) {
 	case PCI_INTR_SMB_SMI:
 		str = "SMI";
 		break;
 	case PCI_INTR_SMB_IRQ9:
 		str = "IRQ 9";
 		break;
+	case PCI_INTR_SMB_IRQ_PCI:
+		str = "PCI IRQ";
+		break;
 	default:
 		str = "BOGUS";
 	}
+
 	device_printf(dev, "intr %s %s ", str,
-	    (value & 1) ? "enabled" : "disabled");
+	    sc->poll == 0 ? "enabled" : "disabled");
 	printf("revision %d\n", pci_read_config(dev, PCI_REVID_SMB, 1));
 
-	if ((value & 0xe) != PCI_INTR_SMB_IRQ9) {
+	if (sc->poll)
+	    goto no_intr;
+
+	if (intr != PCI_INTR_SMB_IRQ9 && intr != PCI_INTR_SMB_IRQ_PCI) {
 		device_printf(dev, "Unsupported interrupt mode\n");
 		error = ENXIO;
 		goto fail;
@@ -151,7 +178,9 @@ intsmb_attach(device_t dev)
 
 	/* Force IRQ 9. */
 	rid = 0;
-	bus_set_resource(dev, SYS_RES_IRQ, rid, 9, 1);
+	if (sc->cfg_irq9)
+		bus_set_resource(dev, SYS_RES_IRQ, rid, 9, 1);
+
 	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
 	    RF_SHAREABLE | RF_ACTIVE);
 	if (sc->irq_res == NULL) {
@@ -167,6 +196,7 @@ intsmb_attach(device_t dev)
 		goto fail;
 	}
 
+no_intr:
 	sc->isbusy = 0;
 	sc->smbus = device_add_child(dev, "smbus", -1);
 	if (sc->smbus == NULL) {
@@ -361,7 +391,7 @@ intsmb_start(struct intsmb_softc *sc, unsigned char cmd, int nointr)
 	tmp |= PIIX4_SMBHSTCNT_START;
 
 	/* While not in autoconfiguration enable interrupts. */
-	if (!cold && !nointr)
+	if (!sc->poll && !cold && !nointr)
 		tmp |= PIIX4_SMBHSTCNT_INTREN;
 	bus_write_1(sc->io_res, PIIX4_SMBHSTCNT, tmp);
 }
@@ -411,8 +441,6 @@ intsmb_stop_poll(struct intsmb_softc *sc)
 		if (!(status & PIIX4_SMBHSTSTAT_BUSY)) {
 			sc->isbusy = 0;
 			error = intsmb_error(sc->dev, status);
-			if (error == 0 && !(status & PIIX4_SMBHSTSTAT_INTR))
-				device_printf(sc->dev, "unknown cause why?\n");
 			return (error);
 		}
 	}
@@ -434,7 +462,7 @@ intsmb_stop(struct intsmb_softc *sc)
 
 	INTSMB_LOCK_ASSERT(sc);
 
-	if (cold)
+	if (sc->poll || cold)
 		/* So that it can use device during device probe on SMBus. */
 		return (intsmb_stop_poll(sc));
 
diff --git a/sys/pci/intpmreg.h b/sys/pci/intpmreg.h
index 236c737..eaebcdd 100644
--- a/sys/pci/intpmreg.h
+++ b/sys/pci/intpmreg.h
@@ -35,7 +35,9 @@
 #define	PCI_BASE_ADDR_SMB	0x90	/* IO BAR. */
 #define	PCI_BASE_ADDR_PM	0x40
 #define	PCI_HST_CFG_SMB		0xd2	/* Host Configuration */
+#define	PCI_INTR_SMB_MASK	0xe
 #define	PCI_INTR_SMB_SMI	0
+#define	PCI_INTR_SMB_IRQ_PCI	2
 #define	PCI_INTR_SMB_IRQ9	8
 #define	PCI_INTR_SMB_ENABLE	1
 #define	PCI_SLV_CMD_SMB		0xd3 /*SLAVE COMMAND*/