aboutsummaryrefslogtreecommitdiff
path: root/drivers/of/irq.c
blob: 598454fbdd1ee1ef234693685e75b83a6fe54edc (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
/*
 *  Derived from arch/i386/kernel/irq.c
 *    Copyright (C) 1992 Linus Torvalds
 *  Adapted from arch/i386 by Gary Thomas
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
 *    Copyright (C) 1996-2001 Cort Dougan
 *  Adapted for Power Macintosh by Paul Mackerras
 *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
 *
 * 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 the code used to make IRQ descriptions in the
 * device tree to actual irq numbers on an interrupt controller
 * driver.
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/string.h>

/**
 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
 * @device: Device node of the device whose interrupt is to be mapped
 * @index: Index of the interrupt to map
 *
 * This function is a wrapper that chains of_irq_map_one() and
 * irq_create_of_mapping() to make things easier to callers
 */
unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
{
	struct of_irq oirq;

	if (of_irq_map_one(dev, index, &oirq))
		return NO_IRQ;

	return irq_create_of_mapping(oirq.controller, oirq.specifier,
				     oirq.size);
}
EXPORT_SYMBOL_GPL(irq_of_parse_and_map);

/**
 * of_irq_find_parent - Given a device node, find its interrupt parent node
 * @child: pointer to device node
 *
 * Returns a pointer to the interrupt parent node, or NULL if the interrupt
 * parent could not be determined.
 */
static struct device_node *of_irq_find_parent(struct device_node *child)
{
	struct device_node *p;
	const phandle *parp;

	if (!of_node_get(child))
		return NULL;

	do {
		parp = of_get_property(child, "interrupt-parent", NULL);
		if (parp == NULL)
			p = of_get_parent(child);
		else {
			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
				p = of_node_get(of_irq_dflt_pic);
			else
				p = of_find_node_by_phandle(*parp);
		}
		of_node_put(child);
		child = p;
	} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);

	return p;
}

/**
 * of_irq_map_raw - Low level interrupt tree parsing
 * @parent:	the device interrupt parent
 * @intspec:	interrupt specifier ("interrupts" property of the device)
 * @ointsize:   size of the passed in interrupt specifier
 * @addr:	address specifier (start of "reg" property of the device)
 * @out_irq:	structure of_irq filled by this function
 *
 * Returns 0 on success and a negative number on error
 *
 * This function is a low-level interrupt tree walking function. It
 * can be used to do a partial walk with synthetized reg and interrupts
 * properties, for example when resolving PCI interrupts when no device
 * node exist for the parent.
 */
int of_irq_map_raw(struct device_node *parent, const u32 *intspec, u32 ointsize,
		const u32 *addr, struct of_irq *out_irq)
{
	struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
	const u32 *tmp, *imap, *imask;
	u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
	int imaplen, match, i;

	pr_debug("of_irq_map_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
	    parent->full_name, intspec[0], intspec[1], ointsize);

	ipar = of_node_get(parent);

	/* First get the #interrupt-cells property of the current cursor
	 * that tells us how to interpret the passed-in intspec. If there
	 * is none, we are nice and just walk up the tree
	 */
	do {
		tmp = of_get_property(ipar, "#interrupt-cells", NULL);
		if (tmp != NULL) {
			intsize = *tmp;
			break;
		}
		tnode = ipar;
		ipar = of_irq_find_parent(ipar);
		of_node_put(tnode);
	} while (ipar);
	if (ipar == NULL) {
		pr_debug(" -> no parent found !\n");
		goto fail;
	}

	pr_debug("of_irq_map_raw: ipar=%s, size=%d\n", ipar->full_name, intsize);

	if (ointsize != intsize)
		return -EINVAL;

	/* Look for this #address-cells. We have to implement the old linux
	 * trick of looking for the parent here as some device-trees rely on it
	 */
	old = of_node_get(ipar);
	do {
		tmp = of_get_property(old, "#address-cells", NULL);
		tnode = of_get_parent(old);
		of_node_put(old);
		old = tnode;
	} while (old && tmp == NULL);
	of_node_put(old);
	old = NULL;
	addrsize = (tmp == NULL) ? 2 : *tmp;

	pr_debug(" -> addrsize=%d\n", addrsize);

	/* Now start the actual "proper" walk of the interrupt tree */
	while (ipar != NULL) {
		/* Now check if cursor is an interrupt-controller and if it is
		 * then we are done
		 */
		if (of_get_property(ipar, "interrupt-controller", NULL) !=
				NULL) {
			pr_debug(" -> got it !\n");
			memcpy(out_irq->specifier, intspec,
			       intsize * sizeof(u32));
			out_irq->size = intsize;
			out_irq->controller = ipar;
			of_node_put(old);
			return 0;
		}

		/* Now look for an interrupt-map */
		imap = of_get_property(ipar, "interrupt-map", &imaplen);
		/* No interrupt map, check for an interrupt parent */
		if (imap == NULL) {
			pr_debug(" -> no map, getting parent\n");
			newpar = of_irq_find_parent(ipar);
			goto skiplevel;
		}
		imaplen /= sizeof(u32);

		/* Look for a mask */
		imask = of_get_property(ipar, "interrupt-map-mask", NULL);

		/* If we were passed no "reg" property and we attempt to parse
		 * an interrupt-map, then #address-cells must be 0.
		 * Fail if it's not.
		 */
		if (addr == NULL && addrsize != 0) {
			pr_debug(" -> no reg passed in when needed !\n");
			goto fail;
		}

		/* Parse interrupt-map */
		match = 0;
		while (imaplen > (addrsize + intsize + 1) && !match) {
			/* Compare specifiers */
			match = 1;
			for (i = 0; i < addrsize && match; ++i) {
				u32 mask = imask ? imask[i] : 0xffffffffu;
				match = ((addr[i] ^ imap[i]) & mask) == 0;
			}
			for (; i < (addrsize + intsize) && match; ++i) {
				u32 mask = imask ? imask[i] : 0xffffffffu;
				match =
				   ((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
			}
			imap += addrsize + intsize;
			imaplen -= addrsize + intsize;

			pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);

			/* Get the interrupt parent */
			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
				newpar = of_node_get(of_irq_dflt_pic);
			else
				newpar = of_find_node_by_phandle((phandle)*imap);
			imap++;
			--imaplen;

			/* Check if not found */
			if (newpar == NULL) {
				pr_debug(" -> imap parent not found !\n");
				goto fail;
			}

			/* Get #interrupt-cells and #address-cells of new
			 * parent
			 */
			tmp = of_get_property(newpar, "#interrupt-cells", NULL);
			if (tmp == NULL) {
				pr_debug(" -> parent lacks #interrupt-cells!\n");
				goto fail;
			}
			newintsize = *tmp;
			tmp = of_get_property(newpar, "#address-cells", NULL);
			newaddrsize = (tmp == NULL) ? 0 : *tmp;

			pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
			    newintsize, newaddrsize);

			/* Check for malformed properties */
			if (imaplen < (newaddrsize + newintsize))
				goto fail;

			imap += newaddrsize + newintsize;
			imaplen -= newaddrsize + newintsize;

			pr_debug(" -> imaplen=%d\n", imaplen);
		}
		if (!match)
			goto fail;

		of_node_put(old);
		old = of_node_get(newpar);
		addrsize = newaddrsize;
		intsize = newintsize;
		intspec = imap - intsize;
		addr = intspec - addrsize;

	skiplevel:
		/* Iterate again with new parent */
		pr_debug(" -> new parent: %s\n", newpar ? newpar->full_name : "<>");
		of_node_put(ipar);
		ipar = newpar;
		newpar = NULL;
	}
 fail:
	of_node_put(ipar);
	of_node_put(old);
	of_node_put(newpar);

	return -EINVAL;
}
EXPORT_SYMBOL_GPL(of_irq_map_raw);

/**
 * of_irq_map_one - Resolve an interrupt for a device
 * @device: the device whose interrupt is to be resolved
 * @index: index of the interrupt to resolve
 * @out_irq: structure of_irq filled by this function
 *
 * This function resolves an interrupt, walking the tree, for a given
 * device-tree node. It's the high level pendant to of_irq_map_raw().
 */
int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq)
{
	struct device_node *p;
	const u32 *intspec, *tmp, *addr;
	u32 intsize, intlen;
	int res = -EINVAL;

	pr_debug("of_irq_map_one: dev=%s, index=%d\n", device->full_name, index);

	/* OldWorld mac stuff is "special", handle out of line */
	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
		return of_irq_map_oldworld(device, index, out_irq);

	/* Get the interrupts property */
	intspec = of_get_property(device, "interrupts", &intlen);
	if (intspec == NULL)
		return -EINVAL;
	intlen /= sizeof(u32);

	pr_debug(" intspec=%d intlen=%d\n", *intspec, intlen);

	/* Get the reg property (if any) */
	addr = of_get_property(device, "reg", NULL);

	/* Look for the interrupt parent. */
	p = of_irq_find_parent(device);
	if (p == NULL)
		return -EINVAL;

	/* Get size of interrupt specifier */
	tmp = of_get_property(p, "#interrupt-cells", NULL);
	if (tmp == NULL)
		goto out;
	intsize = *tmp;

	pr_debug(" intsize=%d intlen=%d\n", intsize, intlen);

	/* Check index */
	if ((index + 1) * intsize > intlen)
		goto out;

	/* Get new specifier and map it */
	res = of_irq_map_raw(p, intspec + index * intsize, intsize,
			     addr, out_irq);
 out:
	of_node_put(p);
	return res;
}
EXPORT_SYMBOL_GPL(of_irq_map_one);

/**
 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
 * @dev: pointer to device tree node
 * @index: zero-based index of the irq
 * @r: pointer to resource structure to return result into.
 */
int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
{
	int irq = irq_of_parse_and_map(dev, index);

	/* Only dereference the resource if both the
	 * resource and the irq are valid. */
	if (r && irq != NO_IRQ) {
		r->start = r->end = irq;
		r->flags = IORESOURCE_IRQ;
	}

	return irq;
}
EXPORT_SYMBOL_GPL(of_irq_to_resource);