summaryrefslogtreecommitdiffstats
path: root/arch/parisc/kernel/drivers.c
blob: fa78419100c84b46a3f7ad9183ffd7748eb5b96b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
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 */
const struct dma_map_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;
		pr_cont(", additional addresses: ");
		for (k = 0; k < dev->num_addrs; k++)
			pr_cont("0x%lx ", dev->addr[k]);
	}
	pr_cont("\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);
}