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* Derived from arch/i386/kernel/irq.c
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* Copyright (C) 1992 Linus Torvalds
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* Adapted from arch/i386 by Gary Thomas
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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* Updated and modified by Cort Dougan <cort@fsmlabs.com>
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* Copyright (C) 1996-2001 Cort Dougan
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* Adapted for Power Macintosh by Paul Mackerras
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* Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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* This file contains the code used to make IRQ descriptions in the
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* device tree to actual irq numbers on an interrupt controller
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#include <linux/errno.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/of_irq.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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* irq_of_parse_and_map - Parse and map an interrupt into linux virq space
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* @device: Device node of the device whose interrupt is to be mapped
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* @index: Index of the interrupt to map
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* This function is a wrapper that chains of_irq_map_one() and
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* irq_create_of_mapping() to make things easier to callers
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unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
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if (of_irq_map_one(dev, index, &oirq))
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return irq_create_of_mapping(oirq.controller, oirq.specifier,
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EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
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* of_irq_find_parent - Given a device node, find its interrupt parent node
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* @child: pointer to device node
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* Returns a pointer to the interrupt parent node, or NULL if the interrupt
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* parent could not be determined.
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struct device_node *of_irq_find_parent(struct device_node *child)
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struct device_node *p;
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if (!of_node_get(child))
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parp = of_get_property(child, "interrupt-parent", NULL);
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p = of_get_parent(child);
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if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
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p = of_node_get(of_irq_dflt_pic);
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p = of_find_node_by_phandle(be32_to_cpup(parp));
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} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
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* of_irq_map_raw - Low level interrupt tree parsing
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* @parent: the device interrupt parent
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* @intspec: interrupt specifier ("interrupts" property of the device)
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* @ointsize: size of the passed in interrupt specifier
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* @addr: address specifier (start of "reg" property of the device)
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* @out_irq: structure of_irq filled by this function
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* Returns 0 on success and a negative number on error
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* This function is a low-level interrupt tree walking function. It
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* can be used to do a partial walk with synthetized reg and interrupts
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* properties, for example when resolving PCI interrupts when no device
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* node exist for the parent.
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int of_irq_map_raw(struct device_node *parent, const __be32 *intspec,
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u32 ointsize, const __be32 *addr, struct of_irq *out_irq)
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struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
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const __be32 *tmp, *imap, *imask;
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u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
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int imaplen, match, i;
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pr_debug("of_irq_map_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
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parent->full_name, be32_to_cpup(intspec),
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be32_to_cpup(intspec + 1), ointsize);
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ipar = of_node_get(parent);
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/* First get the #interrupt-cells property of the current cursor
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* that tells us how to interpret the passed-in intspec. If there
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* is none, we are nice and just walk up the tree
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tmp = of_get_property(ipar, "#interrupt-cells", NULL);
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intsize = be32_to_cpu(*tmp);
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ipar = of_irq_find_parent(ipar);
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pr_debug(" -> no parent found !\n");
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pr_debug("of_irq_map_raw: ipar=%s, size=%d\n", ipar->full_name, intsize);
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if (ointsize != intsize)
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/* Look for this #address-cells. We have to implement the old linux
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* trick of looking for the parent here as some device-trees rely on it
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old = of_node_get(ipar);
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tmp = of_get_property(old, "#address-cells", NULL);
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tnode = of_get_parent(old);
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} while (old && tmp == NULL);
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addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
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pr_debug(" -> addrsize=%d\n", addrsize);
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/* Now start the actual "proper" walk of the interrupt tree */
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while (ipar != NULL) {
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/* Now check if cursor is an interrupt-controller and if it is
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if (of_get_property(ipar, "interrupt-controller", NULL) !=
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pr_debug(" -> got it !\n");
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for (i = 0; i < intsize; i++)
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out_irq->specifier[i] =
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of_read_number(intspec +i, 1);
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out_irq->size = intsize;
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out_irq->controller = ipar;
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/* Now look for an interrupt-map */
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imap = of_get_property(ipar, "interrupt-map", &imaplen);
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/* No interrupt map, check for an interrupt parent */
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pr_debug(" -> no map, getting parent\n");
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newpar = of_irq_find_parent(ipar);
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imaplen /= sizeof(u32);
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/* Look for a mask */
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imask = of_get_property(ipar, "interrupt-map-mask", NULL);
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/* If we were passed no "reg" property and we attempt to parse
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* an interrupt-map, then #address-cells must be 0.
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if (addr == NULL && addrsize != 0) {
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pr_debug(" -> no reg passed in when needed !\n");
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/* Parse interrupt-map */
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while (imaplen > (addrsize + intsize + 1) && !match) {
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/* Compare specifiers */
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for (i = 0; i < addrsize && match; ++i) {
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u32 mask = imask ? imask[i] : 0xffffffffu;
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match = ((addr[i] ^ imap[i]) & mask) == 0;
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for (; i < (addrsize + intsize) && match; ++i) {
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u32 mask = imask ? imask[i] : 0xffffffffu;
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((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
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imap += addrsize + intsize;
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imaplen -= addrsize + intsize;
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pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
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/* Get the interrupt parent */
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if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
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newpar = of_node_get(of_irq_dflt_pic);
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newpar = of_find_node_by_phandle(be32_to_cpup(imap));
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/* Check if not found */
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if (newpar == NULL) {
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pr_debug(" -> imap parent not found !\n");
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/* Get #interrupt-cells and #address-cells of new
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tmp = of_get_property(newpar, "#interrupt-cells", NULL);
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pr_debug(" -> parent lacks #interrupt-cells!\n");
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newintsize = be32_to_cpu(*tmp);
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tmp = of_get_property(newpar, "#address-cells", NULL);
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newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*tmp);
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pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
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newintsize, newaddrsize);
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/* Check for malformed properties */
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if (imaplen < (newaddrsize + newintsize))
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imap += newaddrsize + newintsize;
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imaplen -= newaddrsize + newintsize;
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pr_debug(" -> imaplen=%d\n", imaplen);
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old = of_node_get(newpar);
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addrsize = newaddrsize;
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intsize = newintsize;
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intspec = imap - intsize;
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addr = intspec - addrsize;
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/* Iterate again with new parent */
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pr_debug(" -> new parent: %s\n", newpar ? newpar->full_name : "<>");
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EXPORT_SYMBOL_GPL(of_irq_map_raw);
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* of_irq_map_one - Resolve an interrupt for a device
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* @device: the device whose interrupt is to be resolved
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* @index: index of the interrupt to resolve
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* @out_irq: structure of_irq filled by this function
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* This function resolves an interrupt, walking the tree, for a given
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* device-tree node. It's the high level pendant to of_irq_map_raw().
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int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq)
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struct device_node *p;
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const __be32 *intspec, *tmp, *addr;
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pr_debug("of_irq_map_one: dev=%s, index=%d\n", device->full_name, index);
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/* OldWorld mac stuff is "special", handle out of line */
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if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
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return of_irq_map_oldworld(device, index, out_irq);
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/* Get the interrupts property */
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intspec = of_get_property(device, "interrupts", &intlen);
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intlen /= sizeof(*intspec);
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pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
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/* Get the reg property (if any) */
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addr = of_get_property(device, "reg", NULL);
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/* Look for the interrupt parent. */
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p = of_irq_find_parent(device);
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/* Get size of interrupt specifier */
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tmp = of_get_property(p, "#interrupt-cells", NULL);
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intsize = be32_to_cpu(*tmp);
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pr_debug(" intsize=%d intlen=%d\n", intsize, intlen);
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if ((index + 1) * intsize > intlen)
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/* Get new specifier and map it */
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res = of_irq_map_raw(p, intspec + index * intsize, intsize,
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EXPORT_SYMBOL_GPL(of_irq_map_one);
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* of_irq_to_resource - Decode a node's IRQ and return it as a resource
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* @dev: pointer to device tree node
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* @index: zero-based index of the irq
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* @r: pointer to resource structure to return result into.
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int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
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int irq = irq_of_parse_and_map(dev, index);
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/* Only dereference the resource if both the
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* resource and the irq are valid. */
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r->start = r->end = irq;
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r->flags = IORESOURCE_IRQ;
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r->name = dev->full_name;
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EXPORT_SYMBOL_GPL(of_irq_to_resource);
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* of_irq_count - Count the number of IRQs a node uses
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* @dev: pointer to device tree node
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int of_irq_count(struct device_node *dev)
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while (of_irq_to_resource(dev, nr, NULL))
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* of_irq_to_resource_table - Fill in resource table with node's IRQ info
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* @dev: pointer to device tree node
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* @res: array of resources to fill in
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* @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
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* Returns the size of the filled in table (up to @nr_irqs).
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int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
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for (i = 0; i < nr_irqs; i++, res++)
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if (!of_irq_to_resource(dev, i, res))
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struct list_head list;
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struct device_node *dev;
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struct device_node *interrupt_parent;
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* of_irq_init - Scan and init matching interrupt controllers in DT
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* @matches: 0 terminated array of nodes to match and init function to call
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* This function scans the device tree for matching interrupt controller nodes,
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* and calls their initialization functions in order with parents first.
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void __init of_irq_init(const struct of_device_id *matches)
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struct device_node *np, *parent = NULL;
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struct intc_desc *desc, *temp_desc;
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struct list_head intc_desc_list, intc_parent_list;
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INIT_LIST_HEAD(&intc_desc_list);
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INIT_LIST_HEAD(&intc_parent_list);
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for_each_matching_node(np, matches) {
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if (!of_find_property(np, "interrupt-controller", NULL))
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* Here, we allocate and populate an intc_desc with the node
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* pointer, interrupt-parent device_node etc.
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desc = kzalloc(sizeof(*desc), GFP_KERNEL);
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desc->interrupt_parent = of_irq_find_parent(np);
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if (desc->interrupt_parent == np)
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desc->interrupt_parent = NULL;
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list_add_tail(&desc->list, &intc_desc_list);
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* The root irq controller is the one without an interrupt-parent.
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* That one goes first, followed by the controllers that reference it,
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* followed by the ones that reference the 2nd level controllers, etc.
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while (!list_empty(&intc_desc_list)) {
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* Process all controllers with the current 'parent'.
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* First pass will be looking for NULL as the parent.
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* The assumption is that NULL parent means a root controller.
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list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
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const struct of_device_id *match;
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of_irq_init_cb_t irq_init_cb;
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if (desc->interrupt_parent != parent)
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list_del(&desc->list);
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match = of_match_node(matches, desc->dev);
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if (WARN(!match->data,
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"of_irq_init: no init function for %s\n",
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match->compatible)) {
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pr_debug("of_irq_init: init %s @ %p, parent %p\n",
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desc->dev, desc->interrupt_parent);
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irq_init_cb = match->data;
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ret = irq_init_cb(desc->dev, desc->interrupt_parent);
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* This one is now set up; add it to the parent list so
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* its children can get processed in a subsequent pass.
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list_add_tail(&desc->list, &intc_parent_list);
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/* Get the next pending parent that might have children */
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desc = list_first_entry(&intc_parent_list, typeof(*desc), list);
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if (list_empty(&intc_parent_list) || !desc) {
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pr_err("of_irq_init: children remain, but no parents\n");
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list_del(&desc->list);
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list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
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list_del(&desc->list);
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list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
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list_del(&desc->list);