i386: add support for picopower irq router

Add support for PicoPower PT86C523 IRQ router to be used with the in-kernel
yenta driver for CardBus.  With this patch cardbus works on e.g.  Dell
Latitude XPi P150CD.

Initial patch for kernel 2.4 series by Sune Mølgaard
http://molgaard.org/code/linux-2.4.31-picopower.patch

Ported to 2.6.20 by Chmouel Boudjnah (http://www.chmouel.com)

Testing and confirmation that it works by Austin Acton

Cleaned up a little for inclusion in a 2.6.21-rc7 based kernel.

Added some more cleanups according to CodingStyle, as noted by
Randy Dunlap on LKML.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Thomas Backlund <tmb@mandriva.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/pci/irq.c

@@ -492,6 +492,26 @@ static int pirq_amd756_set(struct pci_dev *router, struct pci_dev *dev, int pirq
 	return 1;
 }
 
+/*
+ * PicoPower PT86C523
+ */
+static int pirq_pico_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
+{
+	outb(0x10 + ((pirq - 1) >> 1), 0x24);
+	return ((pirq - 1) & 1) ? (inb(0x26) >> 4) : (inb(0x26) & 0xf);
+}
+
+static int pirq_pico_set(struct pci_dev *router, struct pci_dev *dev, int pirq,
+			int irq)
+{
+	unsigned int x;
+	outb(0x10 + ((pirq - 1) >> 1), 0x24);
+	x = inb(0x26);
+	x = ((pirq - 1) & 1) ? ((x & 0x0f) | (irq << 4)) : ((x & 0xf0) | (irq));
+	outb(x, 0x26);
+	return 1;
+}
+
 #ifdef CONFIG_PCI_BIOS
 
 static int pirq_bios_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
@@ -721,6 +741,24 @@ static __init int amd_router_probe(struct irq_router *r, struct pci_dev *router,
 	return 1;
 }
 
+static __init int pico_router_probe(struct irq_router *r, struct pci_dev *router, u16 device)
+{
+	switch (device) {
+	case PCI_DEVICE_ID_PICOPOWER_PT86C523:
+		r->name = "PicoPower PT86C523";
+		r->get = pirq_pico_get;
+		r->set = pirq_pico_set;
+		return 1;
+
+	case PCI_DEVICE_ID_PICOPOWER_PT86C523BBP:
+		r->name = "PicoPower PT86C523 rev. BB+";
+		r->get = pirq_pico_get;
+		r->set = pirq_pico_set;
+		return 1;
+	}
+	return 0;
+}
+
 static __initdata struct irq_router_handler pirq_routers[] = {
 	{ PCI_VENDOR_ID_INTEL, intel_router_probe },
 	{ PCI_VENDOR_ID_AL, ali_router_probe },
@@ -732,6 +770,7 @@ static __initdata struct irq_router_handler pirq_routers[] = {
 	{ PCI_VENDOR_ID_VLSI, vlsi_router_probe },
 	{ PCI_VENDOR_ID_SERVERWORKS, serverworks_router_probe },
 	{ PCI_VENDOR_ID_AMD, amd_router_probe },
+	{ PCI_VENDOR_ID_PICOPOWER, pico_router_probe },
 	/* Someone with docs needs to add the ATI Radeon IGP */
 	{ 0, NULL }
 };

include/linux/pci_ids.h

@@ -829,6 +829,9 @@
 #define PCI_DEVICE_ID_UMC_UM8886BF	0x673a
 #define PCI_DEVICE_ID_UMC_UM8886A	0x886a
 
+#define PCI_VENDOR_ID_PICOPOWER		0x1066
+#define PCI_DEVICE_ID_PICOPOWER_PT86C523	0x0002
+#define PCI_DEVICE_ID_PICOPOWER_PT86C523BBP	0x8002
 
 #define PCI_VENDOR_ID_MYLEX		0x1069
 #define PCI_DEVICE_ID_MYLEX_DAC960_P	0x0001