Initial import

1 files changed, 911 insertions, 0 deletions

diff --git a/arch/parisc/kernel/drivers.c b/arch/parisc/kernel/drivers.c
new file mode 100644
index 000000000..dba508fe1
--- /dev/null
+++ b/arch/parisc/kernel/drivers.c
@@ -0,0 +1,911 @@
+/*
+ * drivers.c
+ *
+ * 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.
+ *
+ * Copyright (c) 1999 The Puffin Group
+ * Copyright (c) 2001 Matthew Wilcox for Hewlett Packard
+ * Copyright (c) 2001 Helge Deller <deller@gmx.de>
+ * Copyright (c) 2001,2002 Ryan Bradetich 
+ * Copyright (c) 2004-2005 Thibaut VARENE <varenet@parisc-linux.org>
+ * 
+ * The file handles registering devices and drivers, then matching them.
+ * It's the closest we get to a dating agency.
+ *
+ * If you're thinking about modifying this file, here are some gotchas to
+ * bear in mind:
+ *  - 715/Mirage device paths have a dummy device between Lasi and its children
+ *  - The EISA adapter may show up as a sibling or child of Wax
+ *  - Dino has an optionally functional serial port.  If firmware enables it,
+ *    it shows up as a child of Dino.  If firmware disables it, the buswalk
+ *    finds it and it shows up as a child of Cujo
+ *  - Dino has both parisc and pci devices as children
+ *  - parisc devices are discovered in a random order, including children
+ *    before parents in some cases.
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/pdc.h>
+#include <asm/parisc-device.h>
+
+/* See comments in include/asm-parisc/pci.h */
+struct hppa_dma_ops *hppa_dma_ops __read_mostly;
+EXPORT_SYMBOL(hppa_dma_ops);
+
+static struct device root = {
+	.init_name = "parisc",
+};
+
+static inline int check_dev(struct device *dev)
+{
+	if (dev->bus == &parisc_bus_type) {
+		struct parisc_device *pdev;
+		pdev = to_parisc_device(dev);
+		return pdev->id.hw_type != HPHW_FAULTY;
+	}
+	return 1;
+}
+
+static struct device *
+parse_tree_node(struct device *parent, int index, struct hardware_path *modpath);
+
+struct recurse_struct {
+	void * obj;
+	int (*fn)(struct device *, void *);
+};
+
+static int descend_children(struct device * dev, void * data)
+{
+	struct recurse_struct * recurse_data = (struct recurse_struct *)data;
+
+	if (recurse_data->fn(dev, recurse_data->obj))
+		return 1;
+	else
+		return device_for_each_child(dev, recurse_data, descend_children);
+}
+
+/**
+ *	for_each_padev - Iterate over all devices in the tree
+ *	@fn:	Function to call for each device.
+ *	@data:	Data to pass to the called function.
+ *
+ *	This performs a depth-first traversal of the tree, calling the
+ *	function passed for each node.  It calls the function for parents
+ *	before children.
+ */
+
+static int for_each_padev(int (*fn)(struct device *, void *), void * data)
+{
+	struct recurse_struct recurse_data = {
+		.obj	= data,
+		.fn	= fn,
+	};
+	return device_for_each_child(&root, &recurse_data, descend_children);
+}
+
+/**
+ * match_device - Report whether this driver can handle this device
+ * @driver: the PA-RISC driver to try
+ * @dev: the PA-RISC device to try
+ */
+static int match_device(struct parisc_driver *driver, struct parisc_device *dev)
+{
+	const struct parisc_device_id *ids;
+
+	for (ids = driver->id_table; ids->sversion; ids++) {
+		if ((ids->sversion != SVERSION_ANY_ID) &&
+		    (ids->sversion != dev->id.sversion))
+			continue;
+
+		if ((ids->hw_type != HWTYPE_ANY_ID) &&
+		    (ids->hw_type != dev->id.hw_type))
+			continue;
+
+		if ((ids->hversion != HVERSION_ANY_ID) &&
+		    (ids->hversion != dev->id.hversion))
+			continue;
+
+		return 1;
+	}
+	return 0;
+}
+
+static int parisc_driver_probe(struct device *dev)
+{
+	int rc;
+	struct parisc_device *pa_dev = to_parisc_device(dev);
+	struct parisc_driver *pa_drv = to_parisc_driver(dev->driver);
+
+	rc = pa_drv->probe(pa_dev);
+
+	if (!rc)
+		pa_dev->driver = pa_drv;
+
+	return rc;
+}
+
+static int parisc_driver_remove(struct device *dev)
+{
+	struct parisc_device *pa_dev = to_parisc_device(dev);
+	struct parisc_driver *pa_drv = to_parisc_driver(dev->driver);
+	if (pa_drv->remove)
+		pa_drv->remove(pa_dev);
+
+	return 0;
+}
+	
+
+/**
+ * register_parisc_driver - Register this driver if it can handle a device
+ * @driver: the PA-RISC driver to try
+ */
+int register_parisc_driver(struct parisc_driver *driver)
+{
+	/* FIXME: we need this because apparently the sti
+	 * driver can be registered twice */
+	if(driver->drv.name) {
+		printk(KERN_WARNING 
+		       "BUG: skipping previously registered driver %s\n",
+		       driver->name);
+		return 1;
+	}
+
+	if (!driver->probe) {
+		printk(KERN_WARNING 
+		       "BUG: driver %s has no probe routine\n",
+		       driver->name);
+		return 1;
+	}
+
+	driver->drv.bus = &parisc_bus_type;
+
+	/* We install our own probe and remove routines */
+	WARN_ON(driver->drv.probe != NULL);
+	WARN_ON(driver->drv.remove != NULL);
+
+	driver->drv.name = driver->name;
+
+	return driver_register(&driver->drv);
+}
+EXPORT_SYMBOL(register_parisc_driver);
+
+
+struct match_count {
+	struct parisc_driver * driver;
+	int count;
+};
+
+static int match_and_count(struct device * dev, void * data)
+{
+	struct match_count * m = data;
+	struct parisc_device * pdev = to_parisc_device(dev);
+
+	if (check_dev(dev)) {
+		if (match_device(m->driver, pdev))
+			m->count++;
+	}
+	return 0;
+}
+
+/**
+ * count_parisc_driver - count # of devices this driver would match
+ * @driver: the PA-RISC driver to try
+ *
+ * Use by IOMMU support to "guess" the right size IOPdir.
+ * Formula is something like memsize/(num_iommu * entry_size).
+ */
+int count_parisc_driver(struct parisc_driver *driver)
+{
+	struct match_count m = {
+		.driver	= driver,
+		.count	= 0,
+	};
+
+	for_each_padev(match_and_count, &m);
+
+	return m.count;
+}
+
+
+
+/**
+ * unregister_parisc_driver - Unregister this driver from the list of drivers
+ * @driver: the PA-RISC driver to unregister
+ */
+int unregister_parisc_driver(struct parisc_driver *driver)
+{
+	driver_unregister(&driver->drv);
+	return 0;
+}
+EXPORT_SYMBOL(unregister_parisc_driver);
+
+struct find_data {
+	unsigned long hpa;
+	struct parisc_device * dev;
+};
+
+static int find_device(struct device * dev, void * data)
+{
+	struct parisc_device * pdev = to_parisc_device(dev);
+	struct find_data * d = (struct find_data*)data;
+
+	if (check_dev(dev)) {
+		if (pdev->hpa.start == d->hpa) {
+			d->dev = pdev;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static struct parisc_device *find_device_by_addr(unsigned long hpa)
+{
+	struct find_data d = {
+		.hpa	= hpa,
+	};
+	int ret;
+
+	ret = for_each_padev(find_device, &d);
+	return ret ? d.dev : NULL;
+}
+
+/**
+ * find_pa_parent_type - Find a parent of a specific type
+ * @dev: The device to start searching from
+ * @type: The device type to search for.
+ *
+ * Walks up the device tree looking for a device of the specified type.
+ * If it finds it, it returns it.  If not, it returns NULL.
+ */
+const struct parisc_device *
+find_pa_parent_type(const struct parisc_device *padev, int type)
+{
+	const struct device *dev = &padev->dev;
+	while (dev != &root) {
+		struct parisc_device *candidate = to_parisc_device(dev);
+		if (candidate->id.hw_type == type)
+			return candidate;
+		dev = dev->parent;
+	}
+
+	return NULL;
+}
+
+/*
+ * get_node_path fills in @path with the firmware path to the device.
+ * Note that if @node is a parisc device, we don't fill in the 'mod' field.
+ * This is because both callers pass the parent and fill in the mod
+ * themselves.  If @node is a PCI device, we do fill it in, even though this
+ * is inconsistent.
+ */
+static void get_node_path(struct device *dev, struct hardware_path *path)
+{
+	int i = 5;
+	memset(&path->bc, -1, 6);
+
+	if (dev_is_pci(dev)) {
+		unsigned int devfn = to_pci_dev(dev)->devfn;
+		path->mod = PCI_FUNC(devfn);
+		path->bc[i--] = PCI_SLOT(devfn);
+		dev = dev->parent;
+	}
+
+	while (dev != &root) {
+		if (dev_is_pci(dev)) {
+			unsigned int devfn = to_pci_dev(dev)->devfn;
+			path->bc[i--] = PCI_SLOT(devfn) | (PCI_FUNC(devfn)<< 5);
+		} else if (dev->bus == &parisc_bus_type) {
+			path->bc[i--] = to_parisc_device(dev)->hw_path;
+		}
+		dev = dev->parent;
+	}
+}
+
+static char *print_hwpath(struct hardware_path *path, char *output)
+{
+	int i;
+	for (i = 0; i < 6; i++) {
+		if (path->bc[i] == -1)
+			continue;
+		output += sprintf(output, "%u/", (unsigned char) path->bc[i]);
+	}
+	output += sprintf(output, "%u", (unsigned char) path->mod);
+	return output;
+}
+
+/**
+ * print_pa_hwpath - Returns hardware path for PA devices
+ * dev: The device to return the path for
+ * output: Pointer to a previously-allocated array to place the path in.
+ *
+ * This function fills in the output array with a human-readable path
+ * to a PA device.  This string is compatible with that used by PDC, and
+ * may be printed on the outside of the box.
+ */
+char *print_pa_hwpath(struct parisc_device *dev, char *output)
+{
+	struct hardware_path path;
+
+	get_node_path(dev->dev.parent, &path);
+	path.mod = dev->hw_path;
+	return print_hwpath(&path, output);
+}
+EXPORT_SYMBOL(print_pa_hwpath);
+
+#if defined(CONFIG_PCI) || defined(CONFIG_ISA)
+/**
+ * get_pci_node_path - Determines the hardware path for a PCI device
+ * @pdev: The device to return the path for
+ * @path: Pointer to a previously-allocated array to place the path in.
+ *
+ * This function fills in the hardware_path structure with the route to
+ * the specified PCI device.  This structure is suitable for passing to
+ * PDC calls.
+ */
+void get_pci_node_path(struct pci_dev *pdev, struct hardware_path *path)
+{
+	get_node_path(&pdev->dev, path);
+}
+EXPORT_SYMBOL(get_pci_node_path);
+
+/**
+ * print_pci_hwpath - Returns hardware path for PCI devices
+ * dev: The device to return the path for
+ * output: Pointer to a previously-allocated array to place the path in.
+ *
+ * This function fills in the output array with a human-readable path
+ * to a PCI device.  This string is compatible with that used by PDC, and
+ * may be printed on the outside of the box.
+ */
+char *print_pci_hwpath(struct pci_dev *dev, char *output)
+{
+	struct hardware_path path;
+
+	get_pci_node_path(dev, &path);
+	return print_hwpath(&path, output);
+}
+EXPORT_SYMBOL(print_pci_hwpath);
+
+#endif /* defined(CONFIG_PCI) || defined(CONFIG_ISA) */
+
+static void setup_bus_id(struct parisc_device *padev)
+{
+	struct hardware_path path;
+	char name[28];
+	char *output = name;
+	int i;
+
+	get_node_path(padev->dev.parent, &path);
+
+	for (i = 0; i < 6; i++) {
+		if (path.bc[i] == -1)
+			continue;
+		output += sprintf(output, "%u:", (unsigned char) path.bc[i]);
+	}
+	sprintf(output, "%u", (unsigned char) padev->hw_path);
+	dev_set_name(&padev->dev, name);
+}
+
+struct parisc_device * create_tree_node(char id, struct device *parent)
+{
+	struct parisc_device *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	dev->hw_path = id;
+	dev->id.hw_type = HPHW_FAULTY;
+
+	dev->dev.parent = parent;
+	setup_bus_id(dev);
+
+	dev->dev.bus = &parisc_bus_type;
+	dev->dma_mask = 0xffffffffUL;	/* PARISC devices are 32-bit */
+
+	/* make the generic dma mask a pointer to the parisc one */
+	dev->dev.dma_mask = &dev->dma_mask;
+	dev->dev.coherent_dma_mask = dev->dma_mask;
+	if (device_register(&dev->dev)) {
+		kfree(dev);
+		return NULL;
+	}
+
+	return dev;
+}
+
+struct match_id_data {
+	char id;
+	struct parisc_device * dev;
+};
+
+static int match_by_id(struct device * dev, void * data)
+{
+	struct parisc_device * pdev = to_parisc_device(dev);
+	struct match_id_data * d = data;
+
+	if (pdev->hw_path == d->id) {
+		d->dev = pdev;
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ * alloc_tree_node - returns a device entry in the iotree
+ * @parent: the parent node in the tree
+ * @id: the element of the module path for this entry
+ *
+ * Checks all the children of @parent for a matching @id.  If none
+ * found, it allocates a new device and returns it.
+ */
+static struct parisc_device * alloc_tree_node(struct device *parent, char id)
+{
+	struct match_id_data d = {
+		.id = id,
+	};
+	if (device_for_each_child(parent, &d, match_by_id))
+		return d.dev;
+	else
+		return create_tree_node(id, parent);
+}
+
+static struct parisc_device *create_parisc_device(struct hardware_path *modpath)
+{
+	int i;
+	struct device *parent = &root;
+	for (i = 0; i < 6; i++) {
+		if (modpath->bc[i] == -1)
+			continue;
+		parent = &alloc_tree_node(parent, modpath->bc[i])->dev;
+	}
+	return alloc_tree_node(parent, modpath->mod);
+}
+
+struct parisc_device *
+alloc_pa_dev(unsigned long hpa, struct hardware_path *mod_path)
+{
+	int status;
+	unsigned long bytecnt;
+	u8 iodc_data[32];
+	struct parisc_device *dev;
+	const char *name;
+
+	/* Check to make sure this device has not already been added - Ryan */
+	if (find_device_by_addr(hpa) != NULL)
+		return NULL;
+
+	status = pdc_iodc_read(&bytecnt, hpa, 0, &iodc_data, 32);
+	if (status != PDC_OK)
+		return NULL;
+
+	dev = create_parisc_device(mod_path);
+	if (dev->id.hw_type != HPHW_FAULTY) {
+		printk(KERN_ERR "Two devices have hardware path [%s].  "
+				"IODC data for second device: "
+				"%02x%02x%02x%02x%02x%02x\n"
+				"Rearranging GSC cards sometimes helps\n",
+			parisc_pathname(dev), iodc_data[0], iodc_data[1],
+			iodc_data[3], iodc_data[4], iodc_data[5], iodc_data[6]);
+		return NULL;
+	}
+
+	dev->id.hw_type = iodc_data[3] & 0x1f;
+	dev->id.hversion = (iodc_data[0] << 4) | ((iodc_data[1] & 0xf0) >> 4);
+	dev->id.hversion_rev = iodc_data[1] & 0x0f;
+	dev->id.sversion = ((iodc_data[4] & 0x0f) << 16) |
+			(iodc_data[5] << 8) | iodc_data[6];
+	dev->hpa.name = parisc_pathname(dev);
+	dev->hpa.start = hpa;
+	/* This is awkward.  The STI spec says that gfx devices may occupy
+	 * 32MB or 64MB.  Unfortunately, we don't know how to tell whether
+	 * it's the former or the latter.  Assumptions either way can hurt us.
+	 */
+	if (hpa == 0xf4000000 || hpa == 0xf8000000) {
+		dev->hpa.end = hpa + 0x03ffffff;
+	} else if (hpa == 0xf6000000 || hpa == 0xfa000000) {
+		dev->hpa.end = hpa + 0x01ffffff;
+	} else {
+		dev->hpa.end = hpa + 0xfff;
+	}
+	dev->hpa.flags = IORESOURCE_MEM;
+	name = parisc_hardware_description(&dev->id);
+	if (name) {
+		strlcpy(dev->name, name, sizeof(dev->name));
+	}
+
+	/* Silently fail things like mouse ports which are subsumed within
+	 * the keyboard controller
+	 */
+	if ((hpa & 0xfff) == 0 && insert_resource(&iomem_resource, &dev->hpa))
+		printk("Unable to claim HPA %lx for device %s\n",
+				hpa, name);
+
+	return dev;
+}
+
+static int parisc_generic_match(struct device *dev, struct device_driver *drv)
+{
+	return match_device(to_parisc_driver(drv), to_parisc_device(dev));
+}
+
+static ssize_t make_modalias(struct device *dev, char *buf)
+{
+	const struct parisc_device *padev = to_parisc_device(dev);
+	const struct parisc_device_id *id = &padev->id;
+
+	return sprintf(buf, "parisc:t%02Xhv%04Xrev%02Xsv%08X\n",
+		(u8)id->hw_type, (u16)id->hversion, (u8)id->hversion_rev,
+		(u32)id->sversion);
+}
+
+static int parisc_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct parisc_device *padev;
+	char modalias[40];
+
+	if (!dev)
+		return -ENODEV;
+
+	padev = to_parisc_device(dev);
+	if (!padev)
+		return -ENODEV;
+
+	if (add_uevent_var(env, "PARISC_NAME=%s", padev->name))
+		return -ENOMEM;
+
+	make_modalias(dev, modalias);
+	if (add_uevent_var(env, "MODALIAS=%s", modalias))
+		return -ENOMEM;
+
+	return 0;
+}
+
+#define pa_dev_attr(name, field, format_string)				\
+static ssize_t name##_show(struct device *dev, struct device_attribute *attr, char *buf)		\
+{									\
+	struct parisc_device *padev = to_parisc_device(dev);		\
+	return sprintf(buf, format_string, padev->field);		\
+}
+
+#define pa_dev_attr_id(field, format) pa_dev_attr(field, id.field, format)
+
+pa_dev_attr(irq, irq, "%u\n");
+pa_dev_attr_id(hw_type, "0x%02x\n");
+pa_dev_attr(rev, id.hversion_rev, "0x%x\n");
+pa_dev_attr_id(hversion, "0x%03x\n");
+pa_dev_attr_id(sversion, "0x%05x\n");
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return make_modalias(dev, buf);
+}
+
+static struct device_attribute parisc_device_attrs[] = {
+	__ATTR_RO(irq),
+	__ATTR_RO(hw_type),
+	__ATTR_RO(rev),
+	__ATTR_RO(hversion),
+	__ATTR_RO(sversion),
+	__ATTR_RO(modalias),
+	__ATTR_NULL,
+};
+
+struct bus_type parisc_bus_type = {
+	.name = "parisc",
+	.match = parisc_generic_match,
+	.uevent = parisc_uevent,
+	.dev_attrs = parisc_device_attrs,
+	.probe = parisc_driver_probe,
+	.remove = parisc_driver_remove,
+};
+
+/**
+ * register_parisc_device - Locate a driver to manage this device.
+ * @dev: The parisc device.
+ *
+ * Search the driver list for a driver that is willing to manage
+ * this device.
+ */
+int register_parisc_device(struct parisc_device *dev)
+{
+	if (!dev)
+		return 0;
+
+	if (dev->driver)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * match_pci_device - Matches a pci device against a given hardware path
+ * entry.
+ * @dev: the generic device (known to be contained by a pci_dev).
+ * @index: the current BC index
+ * @modpath: the hardware path.
+ * @return: true if the device matches the hardware path.
+ */
+static int match_pci_device(struct device *dev, int index,
+		struct hardware_path *modpath)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int id;
+
+	if (index == 5) {
+		/* we are at the end of the path, and on the actual device */
+		unsigned int devfn = pdev->devfn;
+		return ((modpath->bc[5] == PCI_SLOT(devfn)) &&
+					(modpath->mod == PCI_FUNC(devfn)));
+	}
+
+	id = PCI_SLOT(pdev->devfn) | (PCI_FUNC(pdev->devfn) << 5);
+	return (modpath->bc[index] == id);
+}
+
+/**
+ * match_parisc_device - Matches a parisc device against a given hardware
+ * path entry.
+ * @dev: the generic device (known to be contained by a parisc_device).
+ * @index: the current BC index
+ * @modpath: the hardware path.
+ * @return: true if the device matches the hardware path.
+ */
+static int match_parisc_device(struct device *dev, int index,
+		struct hardware_path *modpath)
+{
+	struct parisc_device *curr = to_parisc_device(dev);
+	char id = (index == 6) ? modpath->mod : modpath->bc[index];
+
+	return (curr->hw_path == id);
+}
+
+struct parse_tree_data {
+	int index;
+	struct hardware_path * modpath;
+	struct device * dev;
+};
+
+static int check_parent(struct device * dev, void * data)
+{
+	struct parse_tree_data * d = data;
+
+	if (check_dev(dev)) {
+		if (dev->bus == &parisc_bus_type) {
+			if (match_parisc_device(dev, d->index, d->modpath))
+				d->dev = dev;
+		} else if (dev_is_pci(dev)) {
+			if (match_pci_device(dev, d->index, d->modpath))
+				d->dev = dev;
+		} else if (dev->bus == NULL) {
+			/* we are on a bus bridge */
+			struct device *new = parse_tree_node(dev, d->index, d->modpath);
+			if (new)
+				d->dev = new;
+		}
+	}
+	return d->dev != NULL;
+}
+
+/**
+ * parse_tree_node - returns a device entry in the iotree
+ * @parent: the parent node in the tree
+ * @index: the current BC index
+ * @modpath: the hardware_path struct to match a device against
+ * @return: The corresponding device if found, NULL otherwise.
+ *
+ * Checks all the children of @parent for a matching @id.  If none
+ * found, it returns NULL.
+ */
+static struct device *
+parse_tree_node(struct device *parent, int index, struct hardware_path *modpath)
+{
+	struct parse_tree_data d = {
+		.index          = index,
+		.modpath        = modpath,
+	};
+
+	struct recurse_struct recurse_data = {
+		.obj	= &d,
+		.fn	= check_parent,
+	};
+
+	if (device_for_each_child(parent, &recurse_data, descend_children))
+		/* nothing */;
+
+	return d.dev;
+}
+
+/**
+ * hwpath_to_device - Finds the generic device corresponding to a given hardware path.
+ * @modpath: the hardware path.
+ * @return: The target device, NULL if not found.
+ */
+struct device *hwpath_to_device(struct hardware_path *modpath)
+{
+	int i;
+	struct device *parent = &root;
+	for (i = 0; i < 6; i++) {
+		if (modpath->bc[i] == -1)
+			continue;
+		parent = parse_tree_node(parent, i, modpath);
+		if (!parent)
+			return NULL;
+	}
+	if (dev_is_pci(parent)) /* pci devices already parse MOD */
+		return parent;
+	else
+		return parse_tree_node(parent, 6, modpath);
+}
+EXPORT_SYMBOL(hwpath_to_device);
+
+/**
+ * device_to_hwpath - Populates the hwpath corresponding to the given device.
+ * @param dev the target device
+ * @param path pointer to a previously allocated hwpath struct to be filled in
+ */
+void device_to_hwpath(struct device *dev, struct hardware_path *path)
+{
+	struct parisc_device *padev;
+	if (dev->bus == &parisc_bus_type) {
+		padev = to_parisc_device(dev);
+		get_node_path(dev->parent, path);
+		path->mod = padev->hw_path;
+	} else if (dev_is_pci(dev)) {
+		get_node_path(dev, path);
+	}
+}
+EXPORT_SYMBOL(device_to_hwpath);
+
+#define BC_PORT_MASK 0x8
+#define BC_LOWER_PORT 0x8
+
+#define BUS_CONVERTER(dev) \
+        ((dev->id.hw_type == HPHW_IOA) || (dev->id.hw_type == HPHW_BCPORT))
+
+#define IS_LOWER_PORT(dev) \
+        ((gsc_readl(dev->hpa.start + offsetof(struct bc_module, io_status)) \
+                & BC_PORT_MASK) == BC_LOWER_PORT)
+
+#define MAX_NATIVE_DEVICES 64
+#define NATIVE_DEVICE_OFFSET 0x1000
+
+#define FLEX_MASK 	F_EXTEND(0xfffc0000)
+#define IO_IO_LOW	offsetof(struct bc_module, io_io_low)
+#define IO_IO_HIGH	offsetof(struct bc_module, io_io_high)
+#define READ_IO_IO_LOW(dev)  (unsigned long)(signed int)gsc_readl(dev->hpa.start + IO_IO_LOW)
+#define READ_IO_IO_HIGH(dev) (unsigned long)(signed int)gsc_readl(dev->hpa.start + IO_IO_HIGH)
+
+static void walk_native_bus(unsigned long io_io_low, unsigned long io_io_high,
+                            struct device *parent);
+
+void walk_lower_bus(struct parisc_device *dev)
+{
+	unsigned long io_io_low, io_io_high;
+
+	if (!BUS_CONVERTER(dev) || IS_LOWER_PORT(dev))
+		return;
+
+	if (dev->id.hw_type == HPHW_IOA) {
+		io_io_low = (unsigned long)(signed int)(READ_IO_IO_LOW(dev) << 16);
+		io_io_high = io_io_low + MAX_NATIVE_DEVICES * NATIVE_DEVICE_OFFSET;
+	} else {
+		io_io_low = (READ_IO_IO_LOW(dev) + ~FLEX_MASK) & FLEX_MASK;
+		io_io_high = (READ_IO_IO_HIGH(dev)+ ~FLEX_MASK) & FLEX_MASK;
+	}
+
+	walk_native_bus(io_io_low, io_io_high, &dev->dev);
+}
+
+/**
+ * walk_native_bus -- Probe a bus for devices
+ * @io_io_low: Base address of this bus.
+ * @io_io_high: Last address of this bus.
+ * @parent: The parent bus device.
+ * 
+ * A native bus (eg Runway or GSC) may have up to 64 devices on it,
+ * spaced at intervals of 0x1000 bytes.  PDC may not inform us of these
+ * devices, so we have to probe for them.  Unfortunately, we may find
+ * devices which are not physically connected (such as extra serial &
+ * keyboard ports).  This problem is not yet solved.
+ */
+static void walk_native_bus(unsigned long io_io_low, unsigned long io_io_high,
+                            struct device *parent)
+{
+	int i, devices_found = 0;
+	unsigned long hpa = io_io_low;
+	struct hardware_path path;
+
+	get_node_path(parent, &path);
+	do {
+		for(i = 0; i < MAX_NATIVE_DEVICES; i++, hpa += NATIVE_DEVICE_OFFSET) {
+			struct parisc_device *dev;
+
+			/* Was the device already added by Firmware? */
+			dev = find_device_by_addr(hpa);
+			if (!dev) {
+				path.mod = i;
+				dev = alloc_pa_dev(hpa, &path);
+				if (!dev)
+					continue;
+
+				register_parisc_device(dev);
+				devices_found++;
+			}
+			walk_lower_bus(dev);
+		}
+	} while(!devices_found && hpa < io_io_high);
+}
+
+#define CENTRAL_BUS_ADDR F_EXTEND(0xfff80000)
+
+/**
+ * walk_central_bus - Find devices attached to the central bus
+ *
+ * PDC doesn't tell us about all devices in the system.  This routine
+ * finds devices connected to the central bus.
+ */
+void walk_central_bus(void)
+{
+	walk_native_bus(CENTRAL_BUS_ADDR,
+			CENTRAL_BUS_ADDR + (MAX_NATIVE_DEVICES * NATIVE_DEVICE_OFFSET),
+			&root);
+}
+
+static void print_parisc_device(struct parisc_device *dev)
+{
+	char hw_path[64];
+	static int count;
+
+	print_pa_hwpath(dev, hw_path);
+	printk(KERN_INFO "%d. %s at 0x%p [%s] { %d, 0x%x, 0x%.3x, 0x%.5x }",
+		++count, dev->name, (void*) dev->hpa.start, hw_path, dev->id.hw_type,
+		dev->id.hversion_rev, dev->id.hversion, dev->id.sversion);
+
+	if (dev->num_addrs) {
+		int k;
+		printk(", additional addresses: ");
+		for (k = 0; k < dev->num_addrs; k++)
+			printk("0x%lx ", dev->addr[k]);
+	}
+	printk("\n");
+}
+
+/**
+ * init_parisc_bus - Some preparation to be done before inventory
+ */
+void init_parisc_bus(void)
+{
+	if (bus_register(&parisc_bus_type))
+		panic("Could not register PA-RISC bus type\n");
+	if (device_register(&root))
+		panic("Could not register PA-RISC root device\n");
+	get_device(&root);
+}
+
+
+static int print_one_device(struct device * dev, void * data)
+{
+	struct parisc_device * pdev = to_parisc_device(dev);
+
+	if (check_dev(dev))
+		print_parisc_device(pdev);
+	return 0;
+}
+
+/**
+ * print_parisc_devices - Print out a list of devices found in this system
+ */
+void print_parisc_devices(void)
+{
+	for_each_padev(print_one_device, NULL);
+}