1 files changed, 349 insertions, 0 deletions

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
new file mode 100644
index 000000000000..6e595e5a3977
--- /dev/null
+++ b/drivers/of/irq.c
@@ -0,0 +1,349 @@
+/*
+ *  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);