linux/kernel/irq/irqdomain.c
Grant Likely 7e71330169 dt/irq: add irq_domain_generate_simple() helper
irq_domain_generate_simple() is an easy way to generate an irq translation
domain for simple irq controllers.  It assumes a flat 1:1 mapping from
hardware irq number to an offset of the first linux irq number assigned
to the controller

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-07-28 01:32:04 -06:00

181 lines
4.9 KiB
C

#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
static LIST_HEAD(irq_domain_list);
static DEFINE_MUTEX(irq_domain_mutex);
/**
* irq_domain_add() - Register an irq_domain
* @domain: ptr to initialized irq_domain structure
*
* Registers an irq_domain structure. The irq_domain must at a minimum be
* initialized with an ops structure pointer, and either a ->to_irq hook or
* a valid irq_base value. Everything else is optional.
*/
void irq_domain_add(struct irq_domain *domain)
{
struct irq_data *d;
int hwirq;
/*
* This assumes that the irq_domain owner has already allocated
* the irq_descs. This block will be removed when support for dynamic
* allocation of irq_descs is added to irq_domain.
*/
for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
if (d || d->domain) {
/* things are broken; just report, don't clean up */
WARN(1, "error: irq_desc already assigned to a domain");
return;
}
d->domain = domain;
d->hwirq = hwirq;
}
mutex_lock(&irq_domain_mutex);
list_add(&domain->list, &irq_domain_list);
mutex_unlock(&irq_domain_mutex);
}
/**
* irq_domain_del() - Unregister an irq_domain
* @domain: ptr to registered irq_domain.
*/
void irq_domain_del(struct irq_domain *domain)
{
struct irq_data *d;
int hwirq;
mutex_lock(&irq_domain_mutex);
list_del(&domain->list);
mutex_unlock(&irq_domain_mutex);
/* Clear the irq_domain assignments */
for (hwirq = 0; hwirq < domain->nr_irq; hwirq++) {
d = irq_get_irq_data(irq_domain_to_irq(domain, hwirq));
d->domain = NULL;
}
}
#if defined(CONFIG_OF_IRQ)
/**
* irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
*
* Used by the device tree interrupt mapping code to translate a device tree
* interrupt specifier to a valid linux irq number. Returns either a valid
* linux IRQ number or 0.
*
* When the caller no longer need the irq number returned by this function it
* should arrange to call irq_dispose_mapping().
*/
unsigned int irq_create_of_mapping(struct device_node *controller,
const u32 *intspec, unsigned int intsize)
{
struct irq_domain *domain;
unsigned long hwirq;
unsigned int irq, type;
int rc = -EINVAL;
/* Find a domain which can translate the irq spec */
mutex_lock(&irq_domain_mutex);
list_for_each_entry(domain, &irq_domain_list, list) {
if (!domain->ops->dt_translate)
continue;
rc = domain->ops->dt_translate(domain, controller,
intspec, intsize, &hwirq, &type);
if (rc == 0)
break;
}
mutex_unlock(&irq_domain_mutex);
if (rc != 0)
return 0;
irq = irq_domain_to_irq(domain, hwirq);
if (type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, type);
pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
controller->full_name, (int)hwirq, irq, type);
return irq;
}
EXPORT_SYMBOL_GPL(irq_create_of_mapping);
/**
* irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
* @irq: linux irq number to be discarded
*
* Calling this function indicates the caller no longer needs a reference to
* the linux irq number returned by a prior call to irq_create_of_mapping().
*/
void irq_dispose_mapping(unsigned int irq)
{
/*
* nothing yet; will be filled when support for dynamic allocation of
* irq_descs is added to irq_domain
*/
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);
int irq_domain_simple_dt_translate(struct irq_domain *d,
struct device_node *controller,
const u32 *intspec, unsigned int intsize,
unsigned long *out_hwirq, unsigned int *out_type)
{
if (d->of_node != controller)
return -EINVAL;
if (intsize < 1)
return -EINVAL;
*out_hwirq = intspec[0];
*out_type = IRQ_TYPE_NONE;
if (intsize > 1)
*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
return 0;
}
struct irq_domain_ops irq_domain_simple_ops = {
.dt_translate = irq_domain_simple_dt_translate,
};
EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
/**
* irq_domain_create_simple() - Set up a 'simple' translation range
*/
void irq_domain_add_simple(struct device_node *controller, int irq_base)
{
struct irq_domain *domain;
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!domain) {
WARN_ON(1);
return;
}
domain->irq_base = irq_base;
domain->of_node = of_node_get(controller);
domain->ops = &irq_domain_simple_ops;
irq_domain_add(domain);
}
EXPORT_SYMBOL_GPL(irq_domain_add_simple);
void irq_domain_generate_simple(const struct of_device_id *match,
u64 phys_base, unsigned int irq_start)
{
struct device_node *node;
pr_info("looking for phys_base=%llx, irq_start=%i\n",
(unsigned long long) phys_base, (int) irq_start);
node = of_find_matching_node_by_address(NULL, match, phys_base);
if (node)
irq_domain_add_simple(node, irq_start);
else
pr_info("no node found\n");
}
EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
#endif /* CONFIG_OF_IRQ */