linux/drivers/of/irq.c

526 lines
15 KiB
C

/*
* 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_parse_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_phandle_args oirq;
if (of_irq_parse_one(dev, index, &oirq))
return 0;
return irq_create_of_mapping(&oirq);
}
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_parse_raw - Low level interrupt tree parsing
* @parent: the device interrupt parent
* @addr: address specifier (start of "reg" property of the device) in be32 format
* @out_irq: structure of_irq updated 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. It takes an interrupt specifier structure as
* input, walks the tree looking for any interrupt-map properties, translates
* the specifier for each map, and then returns the translated map.
*/
int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
{
struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
__be32 initial_match_array[MAX_PHANDLE_ARGS];
const __be32 *match_array = initial_match_array;
const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
int imaplen, match, i;
#ifdef DEBUG
of_print_phandle_args("of_irq_parse_raw: ", out_irq);
#endif
ipar = of_node_get(out_irq->np);
/* 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_parse_raw: ipar=%s, size=%d\n", of_node_full_name(ipar), intsize);
if (out_irq->args_count != 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);
/* Range check so that the temporary buffer doesn't overflow */
if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS))
goto fail;
/* Precalculate the match array - this simplifies match loop */
for (i = 0; i < addrsize; i++)
initial_match_array[i] = addr ? addr[i] : 0;
for (i = 0; i < intsize; i++)
initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
/* 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");
return 0;
}
/*
* interrupt-map parsing does not work without a reg
* property when #address-cells != 0
*/
if (addrsize && !addr) {
pr_debug(" -> no reg passed in when needed !\n");
goto fail;
}
/* 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 (!imask)
imask = dummy_imask;
/* Parse interrupt-map */
match = 0;
while (imaplen > (addrsize + intsize + 1) && !match) {
/* Compare specifiers */
match = 1;
for (i = 0; i < (addrsize + intsize); i++, imaplen--)
match &= !((match_array[i] ^ *imap++) & imask[i]);
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;
}
if (!of_device_is_available(newpar))
match = 0;
/* 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 (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS))
goto fail;
if (imaplen < (newaddrsize + newintsize))
goto fail;
imap += newaddrsize + newintsize;
imaplen -= newaddrsize + newintsize;
pr_debug(" -> imaplen=%d\n", imaplen);
}
if (!match)
goto fail;
/*
* Successfully parsed an interrrupt-map translation; copy new
* interrupt specifier into the out_irq structure
*/
out_irq->np = newpar;
match_array = imap - newaddrsize - newintsize;
for (i = 0; i < newintsize; i++)
out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
out_irq->args_count = intsize = newintsize;
addrsize = newaddrsize;
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(newpar);
return -EINVAL;
}
EXPORT_SYMBOL_GPL(of_irq_parse_raw);
/**
* of_irq_parse_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 for a node by walking the interrupt tree,
* finding which interrupt controller node it is attached to, and returning the
* interrupt specifier that can be used to retrieve a Linux IRQ number.
*/
int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
{
struct device_node *p;
const __be32 *intspec, *tmp, *addr;
u32 intsize, intlen;
int i, res = -EINVAL;
pr_debug("of_irq_parse_one: dev=%s, index=%d\n", of_node_full_name(device), index);
/* OldWorld mac stuff is "special", handle out of line */
if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
return of_irq_parse_oldworld(device, index, out_irq);
/* Get the reg property (if any) */
addr = of_get_property(device, "reg", NULL);
/* Get the interrupts property */
intspec = of_get_property(device, "interrupts", &intlen);
if (intspec == NULL) {
/* Try the new-style interrupts-extended */
res = of_parse_phandle_with_args(device, "interrupts-extended",
"#interrupt-cells", index, out_irq);
if (res)
return -EINVAL;
return of_irq_parse_raw(addr, out_irq);
}
intlen /= sizeof(*intspec);
pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen);
/* 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;
/* Copy intspec into irq structure */
intspec += index * intsize;
out_irq->np = p;
out_irq->args_count = intsize;
for (i = 0; i < intsize; i++)
out_irq->args[i] = be32_to_cpup(intspec++);
/* Check if there are any interrupt-map translations to process */
res = of_irq_parse_raw(addr, out_irq);
out:
of_node_put(p);
return res;
}
EXPORT_SYMBOL_GPL(of_irq_parse_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 | irqd_get_trigger_type(irq_get_irq_data(irq));
r->name = name ? name : of_node_full_name(dev);
}
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)
{
struct of_phandle_args irq;
int nr = 0;
while (of_irq_parse_one(dev, nr, &irq) == 0)
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) ||
!of_device_is_available(np))
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);
}
}