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)
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.
16 * This file contains the code used to make IRQ descriptions in the
17 * device tree to actual irq numbers on an interrupt controller
21 #include <linux/errno.h>
22 #include <linux/module.h>
24 #include <linux/of_irq.h>
25 #include <linux/string.h>
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
32 * This function is a wrapper that chains of_irq_map_one() and
33 * irq_create_of_mapping() to make things easier to callers
35 unsigned int irq_of_parse_and_map(struct device_node
*dev
, int index
)
39 if (of_irq_map_one(dev
, index
, &oirq
))
42 return irq_create_of_mapping(oirq
.controller
, oirq
.specifier
,
45 EXPORT_SYMBOL_GPL(irq_of_parse_and_map
);
48 * of_irq_find_parent - Given a device node, find its interrupt parent node
49 * @child: pointer to device node
51 * Returns a pointer to the interrupt parent node, or NULL if the interrupt
52 * parent could not be determined.
54 static struct device_node
*of_irq_find_parent(struct device_node
*child
)
56 struct device_node
*p
;
59 if (!of_node_get(child
))
63 parp
= of_get_property(child
, "interrupt-parent", NULL
);
65 p
= of_get_parent(child
);
67 if (of_irq_workarounds
& OF_IMAP_NO_PHANDLE
)
68 p
= of_node_get(of_irq_dflt_pic
);
70 p
= of_find_node_by_phandle(be32_to_cpup(parp
));
74 } while (p
&& of_get_property(p
, "#interrupt-cells", NULL
) == NULL
);
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
87 * Returns 0 on success and a negative number on error
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.
94 int of_irq_map_raw(struct device_node
*parent
, const __be32
*intspec
,
95 u32 ointsize
, const __be32
*addr
, struct of_irq
*out_irq
)
97 struct device_node
*ipar
, *tnode
, *old
= NULL
, *newpar
= NULL
;
98 const __be32
*tmp
, *imap
, *imask
;
99 u32 intsize
= 1, addrsize
, newintsize
= 0, newaddrsize
= 0;
100 int imaplen
, match
, i
;
102 pr_debug("of_irq_map_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
103 parent
->full_name
, be32_to_cpup(intspec
),
104 be32_to_cpup(intspec
+ 1), ointsize
);
106 ipar
= of_node_get(parent
);
108 /* First get the #interrupt-cells property of the current cursor
109 * that tells us how to interpret the passed-in intspec. If there
110 * is none, we are nice and just walk up the tree
113 tmp
= of_get_property(ipar
, "#interrupt-cells", NULL
);
115 intsize
= be32_to_cpu(*tmp
);
119 ipar
= of_irq_find_parent(ipar
);
123 pr_debug(" -> no parent found !\n");
127 pr_debug("of_irq_map_raw: ipar=%s, size=%d\n", ipar
->full_name
, intsize
);
129 if (ointsize
!= intsize
)
132 /* Look for this #address-cells. We have to implement the old linux
133 * trick of looking for the parent here as some device-trees rely on it
135 old
= of_node_get(ipar
);
137 tmp
= of_get_property(old
, "#address-cells", NULL
);
138 tnode
= of_get_parent(old
);
141 } while (old
&& tmp
== NULL
);
144 addrsize
= (tmp
== NULL
) ? 2 : be32_to_cpu(*tmp
);
146 pr_debug(" -> addrsize=%d\n", addrsize
);
148 /* Now start the actual "proper" walk of the interrupt tree */
149 while (ipar
!= NULL
) {
150 /* Now check if cursor is an interrupt-controller and if it is
153 if (of_get_property(ipar
, "interrupt-controller", NULL
) !=
155 pr_debug(" -> got it !\n");
156 for (i
= 0; i
< intsize
; i
++)
157 out_irq
->specifier
[i
] =
158 of_read_number(intspec
+i
, 1);
159 out_irq
->size
= intsize
;
160 out_irq
->controller
= ipar
;
165 /* Now look for an interrupt-map */
166 imap
= of_get_property(ipar
, "interrupt-map", &imaplen
);
167 /* No interrupt map, check for an interrupt parent */
169 pr_debug(" -> no map, getting parent\n");
170 newpar
= of_irq_find_parent(ipar
);
173 imaplen
/= sizeof(u32
);
175 /* Look for a mask */
176 imask
= of_get_property(ipar
, "interrupt-map-mask", NULL
);
178 /* If we were passed no "reg" property and we attempt to parse
179 * an interrupt-map, then #address-cells must be 0.
182 if (addr
== NULL
&& addrsize
!= 0) {
183 pr_debug(" -> no reg passed in when needed !\n");
187 /* Parse interrupt-map */
189 while (imaplen
> (addrsize
+ intsize
+ 1) && !match
) {
190 /* Compare specifiers */
192 for (i
= 0; i
< addrsize
&& match
; ++i
) {
193 u32 mask
= imask
? imask
[i
] : 0xffffffffu
;
194 match
= ((addr
[i
] ^ imap
[i
]) & mask
) == 0;
196 for (; i
< (addrsize
+ intsize
) && match
; ++i
) {
197 u32 mask
= imask
? imask
[i
] : 0xffffffffu
;
199 ((intspec
[i
-addrsize
] ^ imap
[i
]) & mask
) == 0;
201 imap
+= addrsize
+ intsize
;
202 imaplen
-= addrsize
+ intsize
;
204 pr_debug(" -> match=%d (imaplen=%d)\n", match
, imaplen
);
206 /* Get the interrupt parent */
207 if (of_irq_workarounds
& OF_IMAP_NO_PHANDLE
)
208 newpar
= of_node_get(of_irq_dflt_pic
);
210 newpar
= of_find_node_by_phandle(be32_to_cpup(imap
));
214 /* Check if not found */
215 if (newpar
== NULL
) {
216 pr_debug(" -> imap parent not found !\n");
220 /* Get #interrupt-cells and #address-cells of new
223 tmp
= of_get_property(newpar
, "#interrupt-cells", NULL
);
225 pr_debug(" -> parent lacks #interrupt-cells!\n");
228 newintsize
= be32_to_cpu(*tmp
);
229 tmp
= of_get_property(newpar
, "#address-cells", NULL
);
230 newaddrsize
= (tmp
== NULL
) ? 0 : be32_to_cpu(*tmp
);
232 pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
233 newintsize
, newaddrsize
);
235 /* Check for malformed properties */
236 if (imaplen
< (newaddrsize
+ newintsize
))
239 imap
+= newaddrsize
+ newintsize
;
240 imaplen
-= newaddrsize
+ newintsize
;
242 pr_debug(" -> imaplen=%d\n", imaplen
);
248 old
= of_node_get(newpar
);
249 addrsize
= newaddrsize
;
250 intsize
= newintsize
;
251 intspec
= imap
- intsize
;
252 addr
= intspec
- addrsize
;
255 /* Iterate again with new parent */
256 pr_debug(" -> new parent: %s\n", newpar
? newpar
->full_name
: "<>");
268 EXPORT_SYMBOL_GPL(of_irq_map_raw
);
271 * of_irq_map_one - Resolve an interrupt for a device
272 * @device: the device whose interrupt is to be resolved
273 * @index: index of the interrupt to resolve
274 * @out_irq: structure of_irq filled by this function
276 * This function resolves an interrupt, walking the tree, for a given
277 * device-tree node. It's the high level pendant to of_irq_map_raw().
279 int of_irq_map_one(struct device_node
*device
, int index
, struct of_irq
*out_irq
)
281 struct device_node
*p
;
282 const __be32
*intspec
, *tmp
, *addr
;
286 pr_debug("of_irq_map_one: dev=%s, index=%d\n", device
->full_name
, index
);
288 /* OldWorld mac stuff is "special", handle out of line */
289 if (of_irq_workarounds
& OF_IMAP_OLDWORLD_MAC
)
290 return of_irq_map_oldworld(device
, index
, out_irq
);
292 /* Get the interrupts property */
293 intspec
= of_get_property(device
, "interrupts", &intlen
);
296 intlen
/= sizeof(*intspec
);
298 pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec
), intlen
);
300 /* Get the reg property (if any) */
301 addr
= of_get_property(device
, "reg", NULL
);
303 /* Look for the interrupt parent. */
304 p
= of_irq_find_parent(device
);
308 /* Get size of interrupt specifier */
309 tmp
= of_get_property(p
, "#interrupt-cells", NULL
);
312 intsize
= be32_to_cpu(*tmp
);
314 pr_debug(" intsize=%d intlen=%d\n", intsize
, intlen
);
317 if ((index
+ 1) * intsize
> intlen
)
320 /* Get new specifier and map it */
321 res
= of_irq_map_raw(p
, intspec
+ index
* intsize
, intsize
,
327 EXPORT_SYMBOL_GPL(of_irq_map_one
);
330 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
331 * @dev: pointer to device tree node
332 * @index: zero-based index of the irq
333 * @r: pointer to resource structure to return result into.
335 int of_irq_to_resource(struct device_node
*dev
, int index
, struct resource
*r
)
337 int irq
= irq_of_parse_and_map(dev
, index
);
339 /* Only dereference the resource if both the
340 * resource and the irq are valid. */
341 if (r
&& irq
!= NO_IRQ
) {
342 r
->start
= r
->end
= irq
;
343 r
->flags
= IORESOURCE_IRQ
;
344 r
->name
= dev
->full_name
;
349 EXPORT_SYMBOL_GPL(of_irq_to_resource
);