/* * 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/list.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_irq.h> #include <linux/string.h> #include <linux/slab.h> /** * irq_of_parse_and_map - Parse and map an interrupt into linux virq space * @dev: 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 0; 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. */ 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) { __be32 mask = imask ? imask[i] : cpu_to_be32(0xffffffffu); match = ((addr[i] ^ imap[i]) & mask) == 0; } for (; i < (addrsize + intsize) && match; ++i) { __be32 mask = imask ? imask[i] : cpu_to_be32(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", of_node_full_name(newpar)); 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) { const char *name = NULL; memset(r, 0, sizeof(*r)); /* * Get optional "interrupts-names" property to add a name * to the resource. */ of_property_read_string_index(dev, "interrupt-names", index, &name); r->start = r->end = irq; r->flags = IORESOURCE_IRQ; r->name = name ? name : dev->full_name; } return irq; } EXPORT_SYMBOL_GPL(of_irq_to_resource); /** * of_irq_count - Count the number of IRQs a node uses * @dev: pointer to device tree node */ int of_irq_count(struct device_node *dev) { int nr = 0; while (of_irq_to_resource(dev, nr, NULL)) nr++; return nr; } /** * of_irq_to_resource_table - Fill in resource table with node's IRQ info * @dev: pointer to device tree node * @res: array of resources to fill in * @nr_irqs: the number of IRQs (and upper bound for num of @res elements) * * Returns the size of the filled in table (up to @nr_irqs). */ int of_irq_to_resource_table(struct device_node *dev, struct resource *res, int nr_irqs) { int i; for (i = 0; i < nr_irqs; i++, res++) if (!of_irq_to_resource(dev, i, res)) break; return i; } EXPORT_SYMBOL_GPL(of_irq_to_resource_table); struct intc_desc { struct list_head list; struct device_node *dev; struct device_node *interrupt_parent; }; /** * of_irq_init - Scan and init matching interrupt controllers in DT * @matches: 0 terminated array of nodes to match and init function to call * * This function scans the device tree for matching interrupt controller nodes, * and calls their initialization functions in order with parents first. */ void __init of_irq_init(const struct of_device_id *matches) { struct device_node *np, *parent = NULL; struct intc_desc *desc, *temp_desc; struct list_head intc_desc_list, intc_parent_list; INIT_LIST_HEAD(&intc_desc_list); INIT_LIST_HEAD(&intc_parent_list); for_each_matching_node(np, matches) { if (!of_find_property(np, "interrupt-controller", NULL)) continue; /* * Here, we allocate and populate an intc_desc with the node * pointer, interrupt-parent device_node etc. */ desc = kzalloc(sizeof(*desc), GFP_KERNEL); if (WARN_ON(!desc)) goto err; desc->dev = np; desc->interrupt_parent = of_irq_find_parent(np); if (desc->interrupt_parent == np) desc->interrupt_parent = NULL; list_add_tail(&desc->list, &intc_desc_list); } /* * The root irq controller is the one without an interrupt-parent. * That one goes first, followed by the controllers that reference it, * followed by the ones that reference the 2nd level controllers, etc. */ while (!list_empty(&intc_desc_list)) { /* * Process all controllers with the current 'parent'. * First pass will be looking for NULL as the parent. * The assumption is that NULL parent means a root controller. */ list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) { const struct of_device_id *match; int ret; of_irq_init_cb_t irq_init_cb; if (desc->interrupt_parent != parent) continue; list_del(&desc->list); match = of_match_node(matches, desc->dev); if (WARN(!match->data, "of_irq_init: no init function for %s\n", match->compatible)) { kfree(desc); continue; } pr_debug("of_irq_init: init %s @ %p, parent %p\n", match->compatible, desc->dev, desc->interrupt_parent); irq_init_cb = (of_irq_init_cb_t)match->data; ret = irq_init_cb(desc->dev, desc->interrupt_parent); if (ret) { kfree(desc); continue; } /* * This one is now set up; add it to the parent list so * its children can get processed in a subsequent pass. */ list_add_tail(&desc->list, &intc_parent_list); } /* Get the next pending parent that might have children */ desc = list_first_entry_or_null(&intc_parent_list, typeof(*desc), list); if (!desc) { pr_err("of_irq_init: children remain, but no parents\n"); break; } list_del(&desc->list); parent = desc->dev; kfree(desc); } list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) { list_del(&desc->list); kfree(desc); } err: list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) { list_del(&desc->list); kfree(desc); } }