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-rw-r--r--drivers/of/irq.c349
1 files changed, 349 insertions, 0 deletions
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
new file mode 100644
index 0000000..6e595e5
--- /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);
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