of: Fix phandle endian issues
[linux-2.6-block.git] / drivers / of / irq.c
CommitLineData
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1/*
2 * Derived from arch/i386/kernel/irq.c
3 * Copyright (C) 1992 Linus Torvalds
4 * Adapted from arch/i386 by Gary Thomas
5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6 * Updated and modified by Cort Dougan <cort@fsmlabs.com>
7 * Copyright (C) 1996-2001 Cort Dougan
8 * Adapted for Power Macintosh by Paul Mackerras
9 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 *
16 * This file contains the code used to make IRQ descriptions in the
17 * device tree to actual irq numbers on an interrupt controller
18 * driver.
19 */
20
21#include <linux/errno.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_irq.h>
25#include <linux/string.h>
26
27/**
28 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
29 * @device: Device node of the device whose interrupt is to be mapped
30 * @index: Index of the interrupt to map
31 *
32 * This function is a wrapper that chains of_irq_map_one() and
33 * irq_create_of_mapping() to make things easier to callers
34 */
35unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
36{
37 struct of_irq oirq;
38
39 if (of_irq_map_one(dev, index, &oirq))
40 return NO_IRQ;
41
42 return irq_create_of_mapping(oirq.controller, oirq.specifier,
43 oirq.size);
44}
45EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
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46
47/**
48 * of_irq_find_parent - Given a device node, find its interrupt parent node
49 * @child: pointer to device node
50 *
51 * Returns a pointer to the interrupt parent node, or NULL if the interrupt
52 * parent could not be determined.
53 */
54static struct device_node *of_irq_find_parent(struct device_node *child)
55{
56 struct device_node *p;
9a6b2e58 57 const __be32 *parp;
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58
59 if (!of_node_get(child))
60 return NULL;
61
62 do {
63 parp = of_get_property(child, "interrupt-parent", NULL);
64 if (parp == NULL)
65 p = of_get_parent(child);
66 else {
67 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
68 p = of_node_get(of_irq_dflt_pic);
69 else
9a6b2e58 70 p = of_find_node_by_phandle(be32_to_cpup(parp));
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71 }
72 of_node_put(child);
73 child = p;
74 } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
75
76 return p;
77}
78
79/**
80 * of_irq_map_raw - Low level interrupt tree parsing
81 * @parent: the device interrupt parent
82 * @intspec: interrupt specifier ("interrupts" property of the device)
83 * @ointsize: size of the passed in interrupt specifier
84 * @addr: address specifier (start of "reg" property of the device)
85 * @out_irq: structure of_irq filled by this function
86 *
87 * Returns 0 on success and a negative number on error
88 *
89 * This function is a low-level interrupt tree walking function. It
90 * can be used to do a partial walk with synthetized reg and interrupts
91 * properties, for example when resolving PCI interrupts when no device
92 * node exist for the parent.
93 */
94int of_irq_map_raw(struct device_node *parent, const u32 *intspec, u32 ointsize,
95 const u32 *addr, struct of_irq *out_irq)
96{
97 struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
a7c194b0 98 const __be32 *tmp, *imap, *imask;
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99 u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
100 int imaplen, match, i;
101
102 pr_debug("of_irq_map_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
103 parent->full_name, intspec[0], intspec[1], ointsize);
104
105 ipar = of_node_get(parent);
106
107 /* First get the #interrupt-cells property of the current cursor
108 * that tells us how to interpret the passed-in intspec. If there
109 * is none, we are nice and just walk up the tree
110 */
111 do {
112 tmp = of_get_property(ipar, "#interrupt-cells", NULL);
113 if (tmp != NULL) {
a7c194b0 114 intsize = be32_to_cpu(*tmp);
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115 break;
116 }
117 tnode = ipar;
118 ipar = of_irq_find_parent(ipar);
119 of_node_put(tnode);
120 } while (ipar);
121 if (ipar == NULL) {
122 pr_debug(" -> no parent found !\n");
123 goto fail;
124 }
125
126 pr_debug("of_irq_map_raw: ipar=%s, size=%d\n", ipar->full_name, intsize);
127
128 if (ointsize != intsize)
129 return -EINVAL;
130
131 /* Look for this #address-cells. We have to implement the old linux
132 * trick of looking for the parent here as some device-trees rely on it
133 */
134 old = of_node_get(ipar);
135 do {
136 tmp = of_get_property(old, "#address-cells", NULL);
137 tnode = of_get_parent(old);
138 of_node_put(old);
139 old = tnode;
140 } while (old && tmp == NULL);
141 of_node_put(old);
142 old = NULL;
a7c194b0 143 addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
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144
145 pr_debug(" -> addrsize=%d\n", addrsize);
146
147 /* Now start the actual "proper" walk of the interrupt tree */
148 while (ipar != NULL) {
149 /* Now check if cursor is an interrupt-controller and if it is
150 * then we are done
151 */
152 if (of_get_property(ipar, "interrupt-controller", NULL) !=
153 NULL) {
154 pr_debug(" -> got it !\n");
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155 for (i = 0; i < intsize; i++)
156 out_irq->specifier[i] =
157 of_read_number(intspec +i, 1);
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158 out_irq->size = intsize;
159 out_irq->controller = ipar;
160 of_node_put(old);
161 return 0;
162 }
163
164 /* Now look for an interrupt-map */
165 imap = of_get_property(ipar, "interrupt-map", &imaplen);
166 /* No interrupt map, check for an interrupt parent */
167 if (imap == NULL) {
168 pr_debug(" -> no map, getting parent\n");
169 newpar = of_irq_find_parent(ipar);
170 goto skiplevel;
171 }
172 imaplen /= sizeof(u32);
173
174 /* Look for a mask */
175 imask = of_get_property(ipar, "interrupt-map-mask", NULL);
176
177 /* If we were passed no "reg" property and we attempt to parse
178 * an interrupt-map, then #address-cells must be 0.
179 * Fail if it's not.
180 */
181 if (addr == NULL && addrsize != 0) {
182 pr_debug(" -> no reg passed in when needed !\n");
183 goto fail;
184 }
185
186 /* Parse interrupt-map */
187 match = 0;
188 while (imaplen > (addrsize + intsize + 1) && !match) {
189 /* Compare specifiers */
190 match = 1;
191 for (i = 0; i < addrsize && match; ++i) {
192 u32 mask = imask ? imask[i] : 0xffffffffu;
193 match = ((addr[i] ^ imap[i]) & mask) == 0;
194 }
195 for (; i < (addrsize + intsize) && match; ++i) {
196 u32 mask = imask ? imask[i] : 0xffffffffu;
197 match =
198 ((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
199 }
200 imap += addrsize + intsize;
201 imaplen -= addrsize + intsize;
202
203 pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
204
205 /* Get the interrupt parent */
206 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
207 newpar = of_node_get(of_irq_dflt_pic);
208 else
9a6b2e58 209 newpar = of_find_node_by_phandle(be32_to_cpup(imap));
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210 imap++;
211 --imaplen;
212
213 /* Check if not found */
214 if (newpar == NULL) {
215 pr_debug(" -> imap parent not found !\n");
216 goto fail;
217 }
218
219 /* Get #interrupt-cells and #address-cells of new
220 * parent
221 */
222 tmp = of_get_property(newpar, "#interrupt-cells", NULL);
223 if (tmp == NULL) {
224 pr_debug(" -> parent lacks #interrupt-cells!\n");
225 goto fail;
226 }
a7c194b0 227 newintsize = be32_to_cpu(*tmp);
7dc2e113 228 tmp = of_get_property(newpar, "#address-cells", NULL);
a7c194b0 229 newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*tmp);
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230
231 pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
232 newintsize, newaddrsize);
233
234 /* Check for malformed properties */
235 if (imaplen < (newaddrsize + newintsize))
236 goto fail;
237
238 imap += newaddrsize + newintsize;
239 imaplen -= newaddrsize + newintsize;
240
241 pr_debug(" -> imaplen=%d\n", imaplen);
242 }
243 if (!match)
244 goto fail;
245
246 of_node_put(old);
247 old = of_node_get(newpar);
248 addrsize = newaddrsize;
249 intsize = newintsize;
250 intspec = imap - intsize;
251 addr = intspec - addrsize;
252
253 skiplevel:
254 /* Iterate again with new parent */
255 pr_debug(" -> new parent: %s\n", newpar ? newpar->full_name : "<>");
256 of_node_put(ipar);
257 ipar = newpar;
258 newpar = NULL;
259 }
260 fail:
261 of_node_put(ipar);
262 of_node_put(old);
263 of_node_put(newpar);
264
265 return -EINVAL;
266}
267EXPORT_SYMBOL_GPL(of_irq_map_raw);
268
269/**
270 * of_irq_map_one - Resolve an interrupt for a device
271 * @device: the device whose interrupt is to be resolved
272 * @index: index of the interrupt to resolve
273 * @out_irq: structure of_irq filled by this function
274 *
275 * This function resolves an interrupt, walking the tree, for a given
276 * device-tree node. It's the high level pendant to of_irq_map_raw().
277 */
278int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq)
279{
280 struct device_node *p;
281 const u32 *intspec, *tmp, *addr;
282 u32 intsize, intlen;
283 int res = -EINVAL;
284
285 pr_debug("of_irq_map_one: dev=%s, index=%d\n", device->full_name, index);
286
287 /* OldWorld mac stuff is "special", handle out of line */
288 if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
289 return of_irq_map_oldworld(device, index, out_irq);
290
291 /* Get the interrupts property */
292 intspec = of_get_property(device, "interrupts", &intlen);
293 if (intspec == NULL)
294 return -EINVAL;
295 intlen /= sizeof(u32);
296
297 pr_debug(" intspec=%d intlen=%d\n", *intspec, intlen);
298
299 /* Get the reg property (if any) */
300 addr = of_get_property(device, "reg", NULL);
301
302 /* Look for the interrupt parent. */
303 p = of_irq_find_parent(device);
304 if (p == NULL)
305 return -EINVAL;
306
307 /* Get size of interrupt specifier */
308 tmp = of_get_property(p, "#interrupt-cells", NULL);
309 if (tmp == NULL)
310 goto out;
a7c194b0 311 intsize = be32_to_cpu(*tmp);
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312
313 pr_debug(" intsize=%d intlen=%d\n", intsize, intlen);
314
315 /* Check index */
316 if ((index + 1) * intsize > intlen)
317 goto out;
318
319 /* Get new specifier and map it */
320 res = of_irq_map_raw(p, intspec + index * intsize, intsize,
321 addr, out_irq);
322 out:
323 of_node_put(p);
324 return res;
325}
326EXPORT_SYMBOL_GPL(of_irq_map_one);
327
328/**
329 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
330 * @dev: pointer to device tree node
331 * @index: zero-based index of the irq
332 * @r: pointer to resource structure to return result into.
333 */
334int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
335{
336 int irq = irq_of_parse_and_map(dev, index);
337
338 /* Only dereference the resource if both the
339 * resource and the irq are valid. */
340 if (r && irq != NO_IRQ) {
341 r->start = r->end = irq;
342 r->flags = IORESOURCE_IRQ;
d3571c3a 343 r->name = dev->full_name;
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344 }
345
346 return irq;
347}
348EXPORT_SYMBOL_GPL(of_irq_to_resource);