xref: /openbmc/linux/arch/parisc/kernel/drivers.c (revision 944d79559d154c12becde0dab327016cf438f46c)
1 /*
2  * drivers.c
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  *
9  * Copyright (c) 1999 The Puffin Group
10  * Copyright (c) 2001 Matthew Wilcox for Hewlett Packard
11  * Copyright (c) 2001 Helge Deller <deller@gmx.de>
12  * Copyright (c) 2001,2002 Ryan Bradetich
13  * Copyright (c) 2004-2005 Thibaut VARENE <varenet@parisc-linux.org>
14  *
15  * The file handles registering devices and drivers, then matching them.
16  * It's the closest we get to a dating agency.
17  *
18  * If you're thinking about modifying this file, here are some gotchas to
19  * bear in mind:
20  *  - 715/Mirage device paths have a dummy device between Lasi and its children
21  *  - The EISA adapter may show up as a sibling or child of Wax
22  *  - Dino has an optionally functional serial port.  If firmware enables it,
23  *    it shows up as a child of Dino.  If firmware disables it, the buswalk
24  *    finds it and it shows up as a child of Cujo
25  *  - Dino has both parisc and pci devices as children
26  *  - parisc devices are discovered in a random order, including children
27  *    before parents in some cases.
28  */
29 
30 #include <linux/slab.h>
31 #include <linux/types.h>
32 #include <linux/kernel.h>
33 #include <linux/pci.h>
34 #include <linux/spinlock.h>
35 #include <linux/string.h>
36 #include <asm/hardware.h>
37 #include <asm/io.h>
38 #include <asm/pdc.h>
39 #include <asm/parisc-device.h>
40 
41 /* See comments in include/asm-parisc/pci.h */
42 struct hppa_dma_ops *hppa_dma_ops __read_mostly;
43 EXPORT_SYMBOL(hppa_dma_ops);
44 
45 static struct device root = {
46 	.bus_id = "parisc",
47 };
48 
49 static inline int check_dev(struct device *dev)
50 {
51 	if (dev->bus == &parisc_bus_type) {
52 		struct parisc_device *pdev;
53 		pdev = to_parisc_device(dev);
54 		return pdev->id.hw_type != HPHW_FAULTY;
55 	}
56 	return 1;
57 }
58 
59 static struct device *
60 parse_tree_node(struct device *parent, int index, struct hardware_path *modpath);
61 
62 struct recurse_struct {
63 	void * obj;
64 	int (*fn)(struct device *, void *);
65 };
66 
67 static int descend_children(struct device * dev, void * data)
68 {
69 	struct recurse_struct * recurse_data = (struct recurse_struct *)data;
70 
71 	if (recurse_data->fn(dev, recurse_data->obj))
72 		return 1;
73 	else
74 		return device_for_each_child(dev, recurse_data, descend_children);
75 }
76 
77 /**
78  *	for_each_padev - Iterate over all devices in the tree
79  *	@fn:	Function to call for each device.
80  *	@data:	Data to pass to the called function.
81  *
82  *	This performs a depth-first traversal of the tree, calling the
83  *	function passed for each node.  It calls the function for parents
84  *	before children.
85  */
86 
87 static int for_each_padev(int (*fn)(struct device *, void *), void * data)
88 {
89 	struct recurse_struct recurse_data = {
90 		.obj	= data,
91 		.fn	= fn,
92 	};
93 	return device_for_each_child(&root, &recurse_data, descend_children);
94 }
95 
96 /**
97  * match_device - Report whether this driver can handle this device
98  * @driver: the PA-RISC driver to try
99  * @dev: the PA-RISC device to try
100  */
101 static int match_device(struct parisc_driver *driver, struct parisc_device *dev)
102 {
103 	const struct parisc_device_id *ids;
104 
105 	for (ids = driver->id_table; ids->sversion; ids++) {
106 		if ((ids->sversion != SVERSION_ANY_ID) &&
107 		    (ids->sversion != dev->id.sversion))
108 			continue;
109 
110 		if ((ids->hw_type != HWTYPE_ANY_ID) &&
111 		    (ids->hw_type != dev->id.hw_type))
112 			continue;
113 
114 		if ((ids->hversion != HVERSION_ANY_ID) &&
115 		    (ids->hversion != dev->id.hversion))
116 			continue;
117 
118 		return 1;
119 	}
120 	return 0;
121 }
122 
123 static int parisc_driver_probe(struct device *dev)
124 {
125 	int rc;
126 	struct parisc_device *pa_dev = to_parisc_device(dev);
127 	struct parisc_driver *pa_drv = to_parisc_driver(dev->driver);
128 
129 	rc = pa_drv->probe(pa_dev);
130 
131 	if (!rc)
132 		pa_dev->driver = pa_drv;
133 
134 	return rc;
135 }
136 
137 static int parisc_driver_remove(struct device *dev)
138 {
139 	struct parisc_device *pa_dev = to_parisc_device(dev);
140 	struct parisc_driver *pa_drv = to_parisc_driver(dev->driver);
141 	if (pa_drv->remove)
142 		pa_drv->remove(pa_dev);
143 
144 	return 0;
145 }
146 
147 
148 /**
149  * register_parisc_driver - Register this driver if it can handle a device
150  * @driver: the PA-RISC driver to try
151  */
152 int register_parisc_driver(struct parisc_driver *driver)
153 {
154 	/* FIXME: we need this because apparently the sti
155 	 * driver can be registered twice */
156 	if(driver->drv.name) {
157 		printk(KERN_WARNING
158 		       "BUG: skipping previously registered driver %s\n",
159 		       driver->name);
160 		return 1;
161 	}
162 
163 	if (!driver->probe) {
164 		printk(KERN_WARNING
165 		       "BUG: driver %s has no probe routine\n",
166 		       driver->name);
167 		return 1;
168 	}
169 
170 	driver->drv.bus = &parisc_bus_type;
171 
172 	/* We install our own probe and remove routines */
173 	WARN_ON(driver->drv.probe != NULL);
174 	WARN_ON(driver->drv.remove != NULL);
175 
176 	driver->drv.name = driver->name;
177 
178 	return driver_register(&driver->drv);
179 }
180 EXPORT_SYMBOL(register_parisc_driver);
181 
182 
183 struct match_count {
184 	struct parisc_driver * driver;
185 	int count;
186 };
187 
188 static int match_and_count(struct device * dev, void * data)
189 {
190 	struct match_count * m = data;
191 	struct parisc_device * pdev = to_parisc_device(dev);
192 
193 	if (check_dev(dev)) {
194 		if (match_device(m->driver, pdev))
195 			m->count++;
196 	}
197 	return 0;
198 }
199 
200 /**
201  * count_parisc_driver - count # of devices this driver would match
202  * @driver: the PA-RISC driver to try
203  *
204  * Use by IOMMU support to "guess" the right size IOPdir.
205  * Formula is something like memsize/(num_iommu * entry_size).
206  */
207 int count_parisc_driver(struct parisc_driver *driver)
208 {
209 	struct match_count m = {
210 		.driver	= driver,
211 		.count	= 0,
212 	};
213 
214 	for_each_padev(match_and_count, &m);
215 
216 	return m.count;
217 }
218 
219 
220 
221 /**
222  * unregister_parisc_driver - Unregister this driver from the list of drivers
223  * @driver: the PA-RISC driver to unregister
224  */
225 int unregister_parisc_driver(struct parisc_driver *driver)
226 {
227 	driver_unregister(&driver->drv);
228 	return 0;
229 }
230 EXPORT_SYMBOL(unregister_parisc_driver);
231 
232 struct find_data {
233 	unsigned long hpa;
234 	struct parisc_device * dev;
235 };
236 
237 static int find_device(struct device * dev, void * data)
238 {
239 	struct parisc_device * pdev = to_parisc_device(dev);
240 	struct find_data * d = (struct find_data*)data;
241 
242 	if (check_dev(dev)) {
243 		if (pdev->hpa.start == d->hpa) {
244 			d->dev = pdev;
245 			return 1;
246 		}
247 	}
248 	return 0;
249 }
250 
251 static struct parisc_device *find_device_by_addr(unsigned long hpa)
252 {
253 	struct find_data d = {
254 		.hpa	= hpa,
255 	};
256 	int ret;
257 
258 	ret = for_each_padev(find_device, &d);
259 	return ret ? d.dev : NULL;
260 }
261 
262 /**
263  * find_pa_parent_type - Find a parent of a specific type
264  * @dev: The device to start searching from
265  * @type: The device type to search for.
266  *
267  * Walks up the device tree looking for a device of the specified type.
268  * If it finds it, it returns it.  If not, it returns NULL.
269  */
270 const struct parisc_device *
271 find_pa_parent_type(const struct parisc_device *padev, int type)
272 {
273 	const struct device *dev = &padev->dev;
274 	while (dev != &root) {
275 		struct parisc_device *candidate = to_parisc_device(dev);
276 		if (candidate->id.hw_type == type)
277 			return candidate;
278 		dev = dev->parent;
279 	}
280 
281 	return NULL;
282 }
283 
284 #ifdef CONFIG_PCI
285 static inline int is_pci_dev(struct device *dev)
286 {
287 	return dev->bus == &pci_bus_type;
288 }
289 #else
290 static inline int is_pci_dev(struct device *dev)
291 {
292 	return 0;
293 }
294 #endif
295 
296 /*
297  * get_node_path fills in @path with the firmware path to the device.
298  * Note that if @node is a parisc device, we don't fill in the 'mod' field.
299  * This is because both callers pass the parent and fill in the mod
300  * themselves.  If @node is a PCI device, we do fill it in, even though this
301  * is inconsistent.
302  */
303 static void get_node_path(struct device *dev, struct hardware_path *path)
304 {
305 	int i = 5;
306 	memset(&path->bc, -1, 6);
307 
308 	if (is_pci_dev(dev)) {
309 		unsigned int devfn = to_pci_dev(dev)->devfn;
310 		path->mod = PCI_FUNC(devfn);
311 		path->bc[i--] = PCI_SLOT(devfn);
312 		dev = dev->parent;
313 	}
314 
315 	while (dev != &root) {
316 		if (is_pci_dev(dev)) {
317 			unsigned int devfn = to_pci_dev(dev)->devfn;
318 			path->bc[i--] = PCI_SLOT(devfn) | (PCI_FUNC(devfn)<< 5);
319 		} else if (dev->bus == &parisc_bus_type) {
320 			path->bc[i--] = to_parisc_device(dev)->hw_path;
321 		}
322 		dev = dev->parent;
323 	}
324 }
325 
326 static char *print_hwpath(struct hardware_path *path, char *output)
327 {
328 	int i;
329 	for (i = 0; i < 6; i++) {
330 		if (path->bc[i] == -1)
331 			continue;
332 		output += sprintf(output, "%u/", (unsigned char) path->bc[i]);
333 	}
334 	output += sprintf(output, "%u", (unsigned char) path->mod);
335 	return output;
336 }
337 
338 /**
339  * print_pa_hwpath - Returns hardware path for PA devices
340  * dev: The device to return the path for
341  * output: Pointer to a previously-allocated array to place the path in.
342  *
343  * This function fills in the output array with a human-readable path
344  * to a PA device.  This string is compatible with that used by PDC, and
345  * may be printed on the outside of the box.
346  */
347 char *print_pa_hwpath(struct parisc_device *dev, char *output)
348 {
349 	struct hardware_path path;
350 
351 	get_node_path(dev->dev.parent, &path);
352 	path.mod = dev->hw_path;
353 	return print_hwpath(&path, output);
354 }
355 EXPORT_SYMBOL(print_pa_hwpath);
356 
357 #if defined(CONFIG_PCI) || defined(CONFIG_ISA)
358 /**
359  * get_pci_node_path - Determines the hardware path for a PCI device
360  * @pdev: The device to return the path for
361  * @path: Pointer to a previously-allocated array to place the path in.
362  *
363  * This function fills in the hardware_path structure with the route to
364  * the specified PCI device.  This structure is suitable for passing to
365  * PDC calls.
366  */
367 void get_pci_node_path(struct pci_dev *pdev, struct hardware_path *path)
368 {
369 	get_node_path(&pdev->dev, path);
370 }
371 EXPORT_SYMBOL(get_pci_node_path);
372 
373 /**
374  * print_pci_hwpath - Returns hardware path for PCI devices
375  * dev: The device to return the path for
376  * output: Pointer to a previously-allocated array to place the path in.
377  *
378  * This function fills in the output array with a human-readable path
379  * to a PCI device.  This string is compatible with that used by PDC, and
380  * may be printed on the outside of the box.
381  */
382 char *print_pci_hwpath(struct pci_dev *dev, char *output)
383 {
384 	struct hardware_path path;
385 
386 	get_pci_node_path(dev, &path);
387 	return print_hwpath(&path, output);
388 }
389 EXPORT_SYMBOL(print_pci_hwpath);
390 
391 #endif /* defined(CONFIG_PCI) || defined(CONFIG_ISA) */
392 
393 static void setup_bus_id(struct parisc_device *padev)
394 {
395 	struct hardware_path path;
396 	char *output = padev->dev.bus_id;
397 	int i;
398 
399 	get_node_path(padev->dev.parent, &path);
400 
401 	for (i = 0; i < 6; i++) {
402 		if (path.bc[i] == -1)
403 			continue;
404 		output += sprintf(output, "%u:", (unsigned char) path.bc[i]);
405 	}
406 	sprintf(output, "%u", (unsigned char) padev->hw_path);
407 }
408 
409 struct parisc_device * create_tree_node(char id, struct device *parent)
410 {
411 	struct parisc_device *dev = kmalloc(sizeof(*dev), GFP_KERNEL);
412 	if (!dev)
413 		return NULL;
414 
415 	memset(dev, 0, sizeof(*dev));
416 	dev->hw_path = id;
417 	dev->id.hw_type = HPHW_FAULTY;
418 
419 	dev->dev.parent = parent;
420 	setup_bus_id(dev);
421 
422 	dev->dev.bus = &parisc_bus_type;
423 	dev->dma_mask = 0xffffffffUL;	/* PARISC devices are 32-bit */
424 
425 	/* make the generic dma mask a pointer to the parisc one */
426 	dev->dev.dma_mask = &dev->dma_mask;
427 	dev->dev.coherent_dma_mask = dev->dma_mask;
428 	device_register(&dev->dev);
429 
430 	return dev;
431 }
432 
433 struct match_id_data {
434 	char id;
435 	struct parisc_device * dev;
436 };
437 
438 static int match_by_id(struct device * dev, void * data)
439 {
440 	struct parisc_device * pdev = to_parisc_device(dev);
441 	struct match_id_data * d = data;
442 
443 	if (pdev->hw_path == d->id) {
444 		d->dev = pdev;
445 		return 1;
446 	}
447 	return 0;
448 }
449 
450 /**
451  * alloc_tree_node - returns a device entry in the iotree
452  * @parent: the parent node in the tree
453  * @id: the element of the module path for this entry
454  *
455  * Checks all the children of @parent for a matching @id.  If none
456  * found, it allocates a new device and returns it.
457  */
458 static struct parisc_device * alloc_tree_node(struct device *parent, char id)
459 {
460 	struct match_id_data d = {
461 		.id = id,
462 	};
463 	if (device_for_each_child(parent, &d, match_by_id))
464 		return d.dev;
465 	else
466 		return create_tree_node(id, parent);
467 }
468 
469 static struct parisc_device *create_parisc_device(struct hardware_path *modpath)
470 {
471 	int i;
472 	struct device *parent = &root;
473 	for (i = 0; i < 6; i++) {
474 		if (modpath->bc[i] == -1)
475 			continue;
476 		parent = &alloc_tree_node(parent, modpath->bc[i])->dev;
477 	}
478 	return alloc_tree_node(parent, modpath->mod);
479 }
480 
481 struct parisc_device *
482 alloc_pa_dev(unsigned long hpa, struct hardware_path *mod_path)
483 {
484 	int status;
485 	unsigned long bytecnt;
486 	u8 iodc_data[32];
487 	struct parisc_device *dev;
488 	const char *name;
489 
490 	/* Check to make sure this device has not already been added - Ryan */
491 	if (find_device_by_addr(hpa) != NULL)
492 		return NULL;
493 
494 	status = pdc_iodc_read(&bytecnt, hpa, 0, &iodc_data, 32);
495 	if (status != PDC_OK)
496 		return NULL;
497 
498 	dev = create_parisc_device(mod_path);
499 	if (dev->id.hw_type != HPHW_FAULTY) {
500 		printk(KERN_ERR "Two devices have hardware path [%s].  "
501 				"IODC data for second device: "
502 				"%02x%02x%02x%02x%02x%02x\n"
503 				"Rearranging GSC cards sometimes helps\n",
504 			parisc_pathname(dev), iodc_data[0], iodc_data[1],
505 			iodc_data[3], iodc_data[4], iodc_data[5], iodc_data[6]);
506 		return NULL;
507 	}
508 
509 	dev->id.hw_type = iodc_data[3] & 0x1f;
510 	dev->id.hversion = (iodc_data[0] << 4) | ((iodc_data[1] & 0xf0) >> 4);
511 	dev->id.hversion_rev = iodc_data[1] & 0x0f;
512 	dev->id.sversion = ((iodc_data[4] & 0x0f) << 16) |
513 			(iodc_data[5] << 8) | iodc_data[6];
514 	dev->hpa.name = parisc_pathname(dev);
515 	dev->hpa.start = hpa;
516 	/* This is awkward.  The STI spec says that gfx devices may occupy
517 	 * 32MB or 64MB.  Unfortunately, we don't know how to tell whether
518 	 * it's the former or the latter.  Assumptions either way can hurt us.
519 	 */
520 	if (hpa == 0xf4000000 || hpa == 0xf8000000) {
521 		dev->hpa.end = hpa + 0x03ffffff;
522 	} else if (hpa == 0xf6000000 || hpa == 0xfa000000) {
523 		dev->hpa.end = hpa + 0x01ffffff;
524 	} else {
525 		dev->hpa.end = hpa + 0xfff;
526 	}
527 	dev->hpa.flags = IORESOURCE_MEM;
528 	name = parisc_hardware_description(&dev->id);
529 	if (name) {
530 		strlcpy(dev->name, name, sizeof(dev->name));
531 	}
532 
533 	/* Silently fail things like mouse ports which are subsumed within
534 	 * the keyboard controller
535 	 */
536 	if ((hpa & 0xfff) == 0 && insert_resource(&iomem_resource, &dev->hpa))
537 		printk("Unable to claim HPA %lx for device %s\n",
538 				hpa, name);
539 
540 	return dev;
541 }
542 
543 static int parisc_generic_match(struct device *dev, struct device_driver *drv)
544 {
545 	return match_device(to_parisc_driver(drv), to_parisc_device(dev));
546 }
547 
548 #define pa_dev_attr(name, field, format_string)				\
549 static ssize_t name##_show(struct device *dev, struct device_attribute *attr, char *buf)		\
550 {									\
551 	struct parisc_device *padev = to_parisc_device(dev);		\
552 	return sprintf(buf, format_string, padev->field);		\
553 }
554 
555 #define pa_dev_attr_id(field, format) pa_dev_attr(field, id.field, format)
556 
557 pa_dev_attr(irq, irq, "%u\n");
558 pa_dev_attr_id(hw_type, "0x%02x\n");
559 pa_dev_attr(rev, id.hversion_rev, "0x%x\n");
560 pa_dev_attr_id(hversion, "0x%03x\n");
561 pa_dev_attr_id(sversion, "0x%05x\n");
562 
563 static struct device_attribute parisc_device_attrs[] = {
564 	__ATTR_RO(irq),
565 	__ATTR_RO(hw_type),
566 	__ATTR_RO(rev),
567 	__ATTR_RO(hversion),
568 	__ATTR_RO(sversion),
569 	__ATTR_NULL,
570 };
571 
572 struct bus_type parisc_bus_type = {
573 	.name = "parisc",
574 	.match = parisc_generic_match,
575 	.dev_attrs = parisc_device_attrs,
576 	.probe = parisc_driver_probe,
577 	.remove = parisc_driver_remove,
578 };
579 
580 /**
581  * register_parisc_device - Locate a driver to manage this device.
582  * @dev: The parisc device.
583  *
584  * Search the driver list for a driver that is willing to manage
585  * this device.
586  */
587 int register_parisc_device(struct parisc_device *dev)
588 {
589 	if (!dev)
590 		return 0;
591 
592 	if (dev->driver)
593 		return 1;
594 
595 	return 0;
596 }
597 
598 /**
599  * match_pci_device - Matches a pci device against a given hardware path
600  * entry.
601  * @dev: the generic device (known to be contained by a pci_dev).
602  * @index: the current BC index
603  * @modpath: the hardware path.
604  * @return: true if the device matches the hardware path.
605  */
606 static int match_pci_device(struct device *dev, int index,
607 		struct hardware_path *modpath)
608 {
609 	struct pci_dev *pdev = to_pci_dev(dev);
610 	int id;
611 
612 	if (index == 5) {
613 		/* we are at the end of the path, and on the actual device */
614 		unsigned int devfn = pdev->devfn;
615 		return ((modpath->bc[5] == PCI_SLOT(devfn)) &&
616 					(modpath->mod == PCI_FUNC(devfn)));
617 	}
618 
619 	id = PCI_SLOT(pdev->devfn) | (PCI_FUNC(pdev->devfn) << 5);
620 	return (modpath->bc[index] == id);
621 }
622 
623 /**
624  * match_parisc_device - Matches a parisc device against a given hardware
625  * path entry.
626  * @dev: the generic device (known to be contained by a parisc_device).
627  * @index: the current BC index
628  * @modpath: the hardware path.
629  * @return: true if the device matches the hardware path.
630  */
631 static int match_parisc_device(struct device *dev, int index,
632 		struct hardware_path *modpath)
633 {
634 	struct parisc_device *curr = to_parisc_device(dev);
635 	char id = (index == 6) ? modpath->mod : modpath->bc[index];
636 
637 	return (curr->hw_path == id);
638 }
639 
640 struct parse_tree_data {
641 	int index;
642 	struct hardware_path * modpath;
643 	struct device * dev;
644 };
645 
646 static int check_parent(struct device * dev, void * data)
647 {
648 	struct parse_tree_data * d = data;
649 
650 	if (check_dev(dev)) {
651 		if (dev->bus == &parisc_bus_type) {
652 			if (match_parisc_device(dev, d->index, d->modpath))
653 				d->dev = dev;
654 		} else if (is_pci_dev(dev)) {
655 			if (match_pci_device(dev, d->index, d->modpath))
656 				d->dev = dev;
657 		} else if (dev->bus == NULL) {
658 			/* we are on a bus bridge */
659 			struct device *new = parse_tree_node(dev, d->index, d->modpath);
660 			if (new)
661 				d->dev = new;
662 		}
663 	}
664 	return d->dev != NULL;
665 }
666 
667 /**
668  * parse_tree_node - returns a device entry in the iotree
669  * @parent: the parent node in the tree
670  * @index: the current BC index
671  * @modpath: the hardware_path struct to match a device against
672  * @return: The corresponding device if found, NULL otherwise.
673  *
674  * Checks all the children of @parent for a matching @id.  If none
675  * found, it returns NULL.
676  */
677 static struct device *
678 parse_tree_node(struct device *parent, int index, struct hardware_path *modpath)
679 {
680 	struct parse_tree_data d = {
681 		.index          = index,
682 		.modpath        = modpath,
683 	};
684 
685 	struct recurse_struct recurse_data = {
686 		.obj	= &d,
687 		.fn	= check_parent,
688 	};
689 
690 	device_for_each_child(parent, &recurse_data, descend_children);
691 	return d.dev;
692 }
693 
694 /**
695  * hwpath_to_device - Finds the generic device corresponding to a given hardware path.
696  * @modpath: the hardware path.
697  * @return: The target device, NULL if not found.
698  */
699 struct device *hwpath_to_device(struct hardware_path *modpath)
700 {
701 	int i;
702 	struct device *parent = &root;
703 	for (i = 0; i < 6; i++) {
704 		if (modpath->bc[i] == -1)
705 			continue;
706 		parent = parse_tree_node(parent, i, modpath);
707 		if (!parent)
708 			return NULL;
709 	}
710 	if (is_pci_dev(parent)) /* pci devices already parse MOD */
711 		return parent;
712 	else
713 		return parse_tree_node(parent, 6, modpath);
714 }
715 EXPORT_SYMBOL(hwpath_to_device);
716 
717 /**
718  * device_to_hwpath - Populates the hwpath corresponding to the given device.
719  * @param dev the target device
720  * @param path pointer to a previously allocated hwpath struct to be filled in
721  */
722 void device_to_hwpath(struct device *dev, struct hardware_path *path)
723 {
724 	struct parisc_device *padev;
725 	if (dev->bus == &parisc_bus_type) {
726 		padev = to_parisc_device(dev);
727 		get_node_path(dev->parent, path);
728 		path->mod = padev->hw_path;
729 	} else if (is_pci_dev(dev)) {
730 		get_node_path(dev, path);
731 	}
732 }
733 EXPORT_SYMBOL(device_to_hwpath);
734 
735 #define BC_PORT_MASK 0x8
736 #define BC_LOWER_PORT 0x8
737 
738 #define BUS_CONVERTER(dev) \
739         ((dev->id.hw_type == HPHW_IOA) || (dev->id.hw_type == HPHW_BCPORT))
740 
741 #define IS_LOWER_PORT(dev) \
742         ((gsc_readl(dev->hpa.start + offsetof(struct bc_module, io_status)) \
743                 & BC_PORT_MASK) == BC_LOWER_PORT)
744 
745 #define MAX_NATIVE_DEVICES 64
746 #define NATIVE_DEVICE_OFFSET 0x1000
747 
748 #define FLEX_MASK 	F_EXTEND(0xfffc0000)
749 #define IO_IO_LOW	offsetof(struct bc_module, io_io_low)
750 #define IO_IO_HIGH	offsetof(struct bc_module, io_io_high)
751 #define READ_IO_IO_LOW(dev)  (unsigned long)(signed int)gsc_readl(dev->hpa.start + IO_IO_LOW)
752 #define READ_IO_IO_HIGH(dev) (unsigned long)(signed int)gsc_readl(dev->hpa.start + IO_IO_HIGH)
753 
754 static void walk_native_bus(unsigned long io_io_low, unsigned long io_io_high,
755                             struct device *parent);
756 
757 void walk_lower_bus(struct parisc_device *dev)
758 {
759 	unsigned long io_io_low, io_io_high;
760 
761 	if (!BUS_CONVERTER(dev) || IS_LOWER_PORT(dev))
762 		return;
763 
764 	if (dev->id.hw_type == HPHW_IOA) {
765 		io_io_low = (unsigned long)(signed int)(READ_IO_IO_LOW(dev) << 16);
766 		io_io_high = io_io_low + MAX_NATIVE_DEVICES * NATIVE_DEVICE_OFFSET;
767 	} else {
768 		io_io_low = (READ_IO_IO_LOW(dev) + ~FLEX_MASK) & FLEX_MASK;
769 		io_io_high = (READ_IO_IO_HIGH(dev)+ ~FLEX_MASK) & FLEX_MASK;
770 	}
771 
772 	walk_native_bus(io_io_low, io_io_high, &dev->dev);
773 }
774 
775 /**
776  * walk_native_bus -- Probe a bus for devices
777  * @io_io_low: Base address of this bus.
778  * @io_io_high: Last address of this bus.
779  * @parent: The parent bus device.
780  *
781  * A native bus (eg Runway or GSC) may have up to 64 devices on it,
782  * spaced at intervals of 0x1000 bytes.  PDC may not inform us of these
783  * devices, so we have to probe for them.  Unfortunately, we may find
784  * devices which are not physically connected (such as extra serial &
785  * keyboard ports).  This problem is not yet solved.
786  */
787 static void walk_native_bus(unsigned long io_io_low, unsigned long io_io_high,
788                             struct device *parent)
789 {
790 	int i, devices_found = 0;
791 	unsigned long hpa = io_io_low;
792 	struct hardware_path path;
793 
794 	get_node_path(parent, &path);
795 	do {
796 		for(i = 0; i < MAX_NATIVE_DEVICES; i++, hpa += NATIVE_DEVICE_OFFSET) {
797 			struct parisc_device *dev;
798 
799 			/* Was the device already added by Firmware? */
800 			dev = find_device_by_addr(hpa);
801 			if (!dev) {
802 				path.mod = i;
803 				dev = alloc_pa_dev(hpa, &path);
804 				if (!dev)
805 					continue;
806 
807 				register_parisc_device(dev);
808 				devices_found++;
809 			}
810 			walk_lower_bus(dev);
811 		}
812 	} while(!devices_found && hpa < io_io_high);
813 }
814 
815 #define CENTRAL_BUS_ADDR F_EXTEND(0xfff80000)
816 
817 /**
818  * walk_central_bus - Find devices attached to the central bus
819  *
820  * PDC doesn't tell us about all devices in the system.  This routine
821  * finds devices connected to the central bus.
822  */
823 void walk_central_bus(void)
824 {
825 	walk_native_bus(CENTRAL_BUS_ADDR,
826 			CENTRAL_BUS_ADDR + (MAX_NATIVE_DEVICES * NATIVE_DEVICE_OFFSET),
827 			&root);
828 }
829 
830 static void print_parisc_device(struct parisc_device *dev)
831 {
832 	char hw_path[64];
833 	static int count;
834 
835 	print_pa_hwpath(dev, hw_path);
836 	printk(KERN_INFO "%d. %s at 0x%lx [%s] { %d, 0x%x, 0x%.3x, 0x%.5x }",
837 		++count, dev->name, dev->hpa.start, hw_path, dev->id.hw_type,
838 		dev->id.hversion_rev, dev->id.hversion, dev->id.sversion);
839 
840 	if (dev->num_addrs) {
841 		int k;
842 		printk(", additional addresses: ");
843 		for (k = 0; k < dev->num_addrs; k++)
844 			printk("0x%lx ", dev->addr[k]);
845 	}
846 	printk("\n");
847 }
848 
849 /**
850  * init_parisc_bus - Some preparation to be done before inventory
851  */
852 void init_parisc_bus(void)
853 {
854 	bus_register(&parisc_bus_type);
855 	device_register(&root);
856 	get_device(&root);
857 }
858 
859 
860 static int print_one_device(struct device * dev, void * data)
861 {
862 	struct parisc_device * pdev = to_parisc_device(dev);
863 
864 	if (check_dev(dev))
865 		print_parisc_device(pdev);
866 	return 0;
867 }
868 
869 /**
870  * print_parisc_devices - Print out a list of devices found in this system
871  */
872 void print_parisc_devices(void)
873 {
874 	for_each_padev(print_one_device, NULL);
875 }
876