/* * 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);