patch-2.4.3 linux/arch/arm/mach-integrator/pci.c

• Lines: 120
• Date: Fri Mar 2 18:38:39 2001
• Orig file: v2.4.2/linux/arch/arm/mach-integrator/pci.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.2/linux/arch/arm/mach-integrator/pci.c linux/arch/arm/mach-integrator/pci.c
@@ -0,0 +1,119 @@
+/*
+ *  linux/arch/arm/mach-integrator/pci-integrator.c
+ *
+ *  Copyright (C) 1999 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *
+ *  PCI functions for Integrator
+ */
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/ptrace.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+
+#include <asm/irq.h>
+#include <asm/system.h>
+#include <asm/mach/pci.h>
+
+/* 
+ * A small note about bridges and interrupts.  The DECchip 21050 (and
+ * later) adheres to the PCI-PCI bridge specification.  This says that
+ * the interrupts on the other side of a bridge are swizzled in the
+ * following manner:
+ *
+ * Dev    Interrupt   Interrupt 
+ *        Pin on      Pin on 
+ *        Device      Connector
+ *
+ *   4    A           A
+ *        B           B
+ *        C           C
+ *        D           D
+ * 
+ *   5    A           B
+ *        B           C
+ *        C           D
+ *        D           A
+ *
+ *   6    A           C
+ *        B           D
+ *        C           A
+ *        D           B
+ *
+ *   7    A           D
+ *        B           A
+ *        C           B
+ *        D           C
+ *
+ * Where A = pin 1, B = pin 2 and so on and pin=0 = default = A.
+ * Thus, each swizzle is ((pin-1) + (device#-4)) % 4
+ *
+ * The following code swizzles for exactly one bridge.  
+ */
+static inline int bridge_swizzle(int pin, unsigned int slot) 
+{
+	return (pin + slot) & 3;
+}
+
+/*
+ * This routine handles multiple bridges.
+ */
+static u8 __init integrator_swizzle(struct pci_dev *dev, u8 *pinp)
+{
+	int pin = *pinp;
+
+	if (pin == 0)
+		pin = 1;
+
+	pin -= 1;
+	while (dev->bus->self) {
+		pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
+		/*
+		 * move up the chain of bridges, swizzling as we go.
+		 */
+		dev = dev->bus->self;
+	}
+	*pinp = pin + 1;
+
+	return PCI_SLOT(dev->devfn);
+}
+
+static int irq_tab[4] __initdata = {
+	IRQ_PCIINT0,	IRQ_PCIINT1,	IRQ_PCIINT2,	IRQ_PCIINT3
+};
+
+/*
+ * map the specified device/slot/pin to an IRQ.  This works out such
+ * that slot 9 pin 1 is INT0, pin 2 is INT1, and slot 10 pin 1 is INT1.
+ */
+static int __init integrator_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
+{
+	int intnr = ((slot - 9) + (pin - 1)) & 3;
+
+	return irq_tab[intnr];
+}
+
+extern void pci_v3_init(struct arm_pci_sysdata *);
+
+struct hw_pci integrator_pci __initdata = {
+	init:		pci_v3_init,
+	swizzle:	integrator_swizzle,
+	map_irq:	integrator_map_irq,
+};