/*
* Routines for tracking a legacy ISA bridge
*
* Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
*
* Some bits and pieces moved over from pci_64.c
*
* Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp.
*
* 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.
*/
#define DEBUG
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/notifier.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>
unsigned long isa_io_base; /* NULL if no ISA bus */
EXPORT_SYMBOL(isa_io_base);
/* Cached ISA bridge dev. */
static struct device_node *isa_bridge_devnode;
struct pci_dev *isa_bridge_pcidev;
EXPORT_SYMBOL_GPL(isa_bridge_pcidev);
#define ISA_SPACE_MASK 0x1
#define ISA_SPACE_IO 0x1
static void pci_process_ISA_OF_ranges(struct device_node *isa_node,
unsigned long phb_io_base_phys)
{
/* We should get some saner parsing here and remove these structs */
struct pci_address {
u32 a_hi;
u32 a_mid;
u32 a_lo;
};
struct isa_address {
u32 a_hi;
u32 a_lo;
};
struct isa_range {
struct isa_address isa_addr;
struct pci_address pci_addr;
unsigned int size;
};
const struct isa_range *range;
unsigned long pci_addr;
unsigned int isa_addr;
unsigned int size;
int rlen = 0;
range = of_get_property(isa_node, "ranges", &rlen);
if (range == NULL || (rlen < sizeof(struct isa_range)))
goto inval_range;
/* From "ISA Binding to 1275"
* The ranges property is laid out as an array of elements,
* each of which comprises:
* cells 0 - 1: an ISA address
* cells 2 - 4: a PCI address
* (size depending on dev->n_addr_cells)
* cell 5: the size of the range
*/
if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO) {
range++;
rlen -= sizeof(struct isa_range);
if (rlen < sizeof(struct isa_range))
goto inval_range;
}
if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO)
goto inval_range;
isa_addr = range->isa_addr.a_lo;
pci_addr = (unsigned long) range->pci_addr.a_mid << 32 |
range->pci_addr.a_lo;
/* Assume these are both zero. Note: We could fix that and
* do a proper parsing instead ... oh well, that will do for
* now as nobody uses fancy mappings for ISA bridges
*/
if ((pci_addr != 0) || (isa_addr != 0)) {
printk(KERN_ERR "unexpected isa to pci mapping: %s\n",
__func__);
return;
}
/* Align size and make sure it's cropped to 64K */
size = PAGE_ALIGN(range->size);
if (size > 0x10000)
size = 0x10000;
__ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,
size, _PAGE_NO_CACHE|_PAGE_GUARDED);
return;
inval_range:
printk(KERN_ERR "no ISA IO ranges or unexpected isa range, "
"mapping 64k\n");
__ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,
0x10000, _PAGE_NO_CACHE|_PAGE_GUARDED);
}
/**
* isa_bridge_find_early - Find and map the ISA IO space early before
* main PCI discovery. This is optionally called by
* the arch code when adding PCI PHBs to get early
* access to ISA IO ports
*/
void __init isa_bridge_find_early(struct pci_controller *hose)
{
struct device_node *np, *parent = NULL, *tmp;
/* If we already have an ISA bridge, bail off */
if (isa_bridge_devnode != NULL)
return;
/* For each "isa" node in the system. Note : we do a search by
* type and not by name. It might be better to do by name but that's
* what the code used to do and I don't want to break too much at
* once. We can look into changing that separately
*/
for_each_node_by_type(np, "isa") {
/* Look for our hose being a parent */
for (parent = of_get_parent(np); parent;) {
if (parent == hose->dn) {
of_node_put(parent);
break;
}
tmp = parent;
parent = of_get_parent(parent);
of_node_put(tmp);
}
if (parent != NULL)
break;
}
if (np == NULL)
return;
isa_bridge_devnode = np;
/* Now parse the "ranges" property and setup the ISA mapping */
pci_process_ISA_OF_ranges(np, hose->io_base_phys);
/* Set the global ISA io base to indicate we have an ISA bridge */
isa_io_base = ISA_IO_BASE;
pr_debug("ISA bridge (early) is %s\n", np->full_name);
}
/**
* isa_bridge_find_late - Find and map the ISA IO space upon discovery of
* a new ISA bridge
*/
static void isa_bridge_find_late(struct pci_dev *pdev,
struct device_node *devnode)
{
struct pci_controller *hose = pci_bus_to_host(pdev->bus);
/* Store ISA device node and PCI device */
isa_bridge_devnode = of_node_get(devnode);
isa_bridge_pcidev = pdev;
/* Now parse the "ranges" property and setup the ISA mapping */
pci_process_ISA_OF_ranges(devnode, hose->io_base_phys);
/* Set the global ISA io base to indicate we have an ISA bridge */
isa_io_base = ISA_IO_BASE;
pr_debug("ISA bridge (late) is %s on %s\n",
devnode->full_name, pci_name(pdev));
}
/**
* isa_bridge_remove - Remove/unmap an ISA bridge
*/
static void isa_bridge_remove(void)
{
pr_debug("ISA bridge removed !\n");
/* Clear the global ISA io base to indicate that we have no more
* ISA bridge. Note that drivers don't quite handle that, though
* we should probably do something about it. But do we ever really
* have ISA bridges being removed on machines using legacy devices ?
*/
isa_io_base = ISA_IO_BASE;
/* Clear references to the bridge */
of_node_put(isa_bridge_devnode);
isa_bridge_devnode = NULL;
isa_bridge_pcidev = NULL;
/* Unmap the ISA area */
__iounmap_at((void *)ISA_IO_BASE, 0x10000);
}
/**
* isa_bridge_notify - Get notified of PCI devices addition/removal
*/
static int isa_bridge_notify(struct notifier_block *nb, unsigned long action,
void *data)
{
struct device *dev = data;
struct pci_dev *pdev = to_pci_dev(dev);
struct device_node *devnode = pci_device_to_OF_node(pdev);
switch(action) {
case BUS_NOTIFY_ADD_DEVICE:
/* Check if we have an early ISA device, without PCI dev */
if (isa_bridge_devnode && isa_bridge_devnode == devnode &&
!isa_bridge_pcidev) {
pr_debug("ISA bridge PCI attached: %s\n",
pci_name(pdev));
isa_bridge_pcidev = pdev;
}
/* Check if we have no ISA device, and this happens to be one,
* register it as such if it has an OF device
*/
if (!isa_bridge_devnode && devnode && devnode->type &&
!strcmp(devnode->type, "isa"))
isa_bridge_find_late(pdev, devnode);
return 0;
case BUS_NOTIFY_DEL_DEVICE:
/* Check if this our existing ISA device */
if (pdev == isa_bridge_pcidev ||
(devnode && devnode == isa_bridge_devnode))
isa_bridge_remove();
return 0;
}
return 0;
}
static struct notifier_block isa_bridge_notifier = {
.notifier_call = isa_bridge_notify
};
/**
* isa_bridge_init - register to be notified of ISA bridge addition/removal
*
*/
static int __init isa_bridge_init(void)
{
bus_register_notifier(&pci_bus_type, &isa_bridge_notifier);
return 0;
}
arch_initcall(isa_bridge_init);
