diff options
Diffstat (limited to 'drivers/of/irq.c')
| -rw-r--r-- | drivers/of/irq.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/drivers/of/irq.c b/drivers/of/irq.c new file mode 100644 index 00000000000..6e595e5a397 --- /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); |