diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-07-05 12:19:19 +0100 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2012-07-11 14:59:17 +0100 |
| commit | 781d0f46d81e2c26c70649903b503bcfe817efc8 (patch) | |
| tree | 11794b64c41e8468db6d14243c5becce3b5b64c8 /kernel/irq | |
| parent | aed98048bd1c83469d96932c1901e867d9ba519a (diff) | |
irq_domain: Standardise legacy/linear domain selection
A large proportion of interrupt controllers that support legacy mappings
do so because non-DT systems need to use fixed IRQ numbers when registering
devices via buses but can otherwise use a linear mapping. The interrupt
controller itself typically is not affected by the mapping used and best
practice is to use a linear mapping where possible so drivers frequently
select at runtime depending on if a legacy range has been allocated to
them.
Standardise this behaviour by providing irq_domain_register_simple() which
will allocate a linear mapping unless a positive first_irq is provided in
which case it will fall back to a legacy mapping. This helps make best
practice for irq_domain adoption clearer.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'kernel/irq')
| -rw-r--r-- | kernel/irq/irqdomain.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index d3968e91bfd2..0c51958c6335 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -140,6 +140,36 @@ static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain, } /** + * irq_domain_add_simple() - Allocate and register a simple irq_domain. + * @of_node: pointer to interrupt controller's device tree node. + * @size: total number of irqs in mapping + * @first_irq: first number of irq block assigned to the domain + * @ops: map/unmap domain callbacks + * @host_data: Controller private data pointer + * + * Allocates a legacy irq_domain if irq_base is positive or a linear + * domain otherwise. + * + * This is intended to implement the expected behaviour for most + * interrupt controllers which is that a linear mapping should + * normally be used unless the system requires a legacy mapping in + * order to support supplying interrupt numbers during non-DT + * registration of devices. + */ +struct irq_domain *irq_domain_add_simple(struct device_node *of_node, + unsigned int size, + unsigned int first_irq, + const struct irq_domain_ops *ops, + void *host_data) +{ + if (first_irq > 0) + return irq_domain_add_legacy(of_node, size, first_irq, 0, + ops, host_data); + else + return irq_domain_add_linear(of_node, size, ops, host_data); +} + +/** * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain. * @of_node: pointer to interrupt controller's device tree node. * @size: total number of irqs in legacy mapping |