patch-2.4.10 linux/arch/mips/ddb5xxx/common/pci.c

• Lines: 180
• Date: Sun Sep 9 10:43:01 2001
• Orig file: v2.4.9/linux/arch/mips/ddb5xxx/common/pci.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.9/linux/arch/mips/ddb5xxx/common/pci.c linux/arch/mips/ddb5xxx/common/pci.c
@@ -0,0 +1,179 @@
+/***********************************************************************
+ * Copyright 2001 MontaVista Software Inc.
+ * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ *
+ * arch/mips/ddb5xxx/common/pci.c
+ *     Common PCI routines for DDB5xxx - as a matter of fact, meant for all 
+ *	MIPS machines.
+ *
+ * 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 file contains common PCI routines meant to be shared for
+ * all MIPS machines.
+ *
+ * Strategies:
+ *
+ * . We rely on pci_auto.c file to assign PCI resources (MEM and IO)
+ *   TODO: this shold be optional for some machines where they do have
+ *   a real "pcibios" that does resource assignment.
+ *
+ * . We then use pci_scan_bus() to "discover" all the resources for
+ *   later use by Linux.
+ *
+ * . We finally reply on a board supplied function, pcibios_fixup_irq(), to 
+ *   to assign the interrupts.  We may use setup-irq.c under drivers/pci
+ *   later.
+ *
+ * . Specifically, we will *NOT* use pci_assign_unassigned_resources(),
+ *   because we assume all PCI devices should have the resources correctly
+ *   assigned and recorded.
+ *
+ * Limitations:
+ *
+ * . We "collapse" all IO and MEM spaces in sub-buses under a top-level bus 
+ *   into a contiguous range.  
+ * 
+ * . In the case of Memory space, the rnage is 1:1 mapping with CPU physical
+ *   address space.
+ *
+ * . In the case of IO space, it starts from 0, and the beginning address
+ *   is mapped to KSEG0ADDR(mips_io_port) in the CPU physical address.
+ *
+ * . These are the current MIPS limitations (by ioremap, etc).  In the
+ *   future, we may remove them.
+ *
+ * Credits:
+ *	Most of the code are derived from the pci routines from PPC and Alpha,
+ *	which were mostly writtne by
+ *		Cort Dougan, cort@fsmlabs.com
+ *		Matt Porter, mporter@mvista.com
+ *		Dave Rusling david.rusling@reo.mts.dec.com
+ *		David Mosberger davidm@cs.arizona.edu
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+
+#include <asm/ddb5xxx/pci.h>
+#include <asm/ddb5xxx/debug.h>
+
+
+struct pci_fixup pcibios_fixups[] = { {0} };
+
+
+extern int pciauto_assign_resources(int busno, struct pci_channel * hose);
+void __init pcibios_init(void)
+{
+	struct pci_channel *p;
+	struct pci_bus *bus;
+	int busno;
+
+	/* assign resources */
+	busno=0;
+	for (p= mips_pci_channels; p->pci_ops != NULL; p++) {
+		busno = pciauto_assign_resources(busno, p) + 1;
+	}
+
+	/* scan the buses */
+	busno = 0;
+	for (p= mips_pci_channels; p->pci_ops != NULL; p++) {
+		bus = pci_scan_bus(busno, p->pci_ops, p);
+		busno = bus->subordinate+1;
+	}
+
+	/* fixup irqs (board specific routines) */
+	pcibios_fixup_irqs();
+
+	/* 
+	 * should we do a fixup of ioport_resource and iomem_resource
+	 * based on mips_pci_channels?  
+	 * Let us wait and see if this is a common need and whether there
+	 * are exceptions.  Until then, each board should adjust them
+	 * perhaps in their setup() function.
+	 */
+}
+
+int pcibios_enable_device(struct pci_dev *dev)
+{
+	/* pciauto_assign_resources() will enable all devices found */
+	return 0;
+}
+
+unsigned long __init
+pci_bridge_check_io(struct pci_dev *bridge)
+{
+        u16 io;
+
+        pci_read_config_word(bridge, PCI_IO_BASE, &io);
+        if (!io) {
+                pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0);
+                pci_read_config_word(bridge, PCI_IO_BASE, &io);
+                pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
+        }
+        if (io)
+                return IORESOURCE_IO;
+        printk(KERN_WARNING "PCI: bridge %s does not support I/O forwarding!\n",
+                                bridge->name);
+        return 0;
+}
+
+void __init pcibios_fixup_bus(struct pci_bus *bus)
+{
+        /* Propogate hose info into the subordinate devices.  */
+
+        struct pci_channel *hose = bus->sysdata;
+        struct pci_dev *dev = bus->self;
+
+        if (!dev) {
+                /* Root bus */
+                bus->resource[0] = hose->io_resource;
+                bus->resource[1] = hose->mem_resource;
+        } else {
+                /* This is a bridge. Do not care how it's initialized,
+                   just link its resources to the bus ones */
+                int i;
+
+                for(i=0; i<3; i++) {
+                        bus->resource[i] =
+                                &dev->resource[PCI_BRIDGE_RESOURCES+i];
+                        bus->resource[i]->name = bus->name;
+                }
+                bus->resource[0]->flags |= pci_bridge_check_io(dev);
+                bus->resource[1]->flags |= IORESOURCE_MEM;
+                /* For now, propogate hose limits to the bus;
+                   we'll adjust them later. */
+                bus->resource[0]->end = hose->io_resource->end;
+                bus->resource[1]->end = hose->mem_resource->end;
+                /* Turn off downstream PF memory address range by default */
+                bus->resource[2]->start = 1024*1024;
+                bus->resource[2]->end = bus->resource[2]->start - 1;
+        }
+}
+
+char *pcibios_setup(char *str)
+{
+	return str;
+}
+
+void
+pcibios_align_resource(void *data, struct resource *res, unsigned long size)
+{
+	/* this should not be called */
+	MIPS_ASSERT(1 == 0);
+}
+
+void
+pcibios_update_resource(struct pci_dev *dev, struct resource *root,
+                             struct resource *res, int resource)
+{
+	/* this should not be called */
+	MIPS_ASSERT(1 == 0);
+}