/*
* 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 __be32 *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(be32_to_cpup(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 __be32 *intspec,
u32 ointsize, const __be32 *addr, struct of_irq *out_irq)
{
struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
const __be32 *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, be32_to_cpup(intspec),
be32_to_cpup(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 = be32_to_cpu(*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 : be32_to_cpu(*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");
for (i = 0; i < intsize; i++)
out_irq->specifier[i] =
of_read_number(intspec +i, 1);
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(be32_to_cpup(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 = be32_to_cpu(*tmp);
tmp = of_get_property(newpar, "#address-cells", NULL);
newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*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 __be32 *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(*intspec);
pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(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 = be32_to_cpu(*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;
r->name = dev->full_name;
}
return irq;
}
EXPORT_SYMBOL_GPL(of_irq_to_resource);
