diff options
| -rw-r--r-- | Documentation/IRQ-domain.txt | 8 | ||||
| -rw-r--r-- | include/linux/irqdomain.h | 23 |
2 files changed, 14 insertions, 17 deletions
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt index 3a8e15cba816..8d990bde8693 100644 --- a/Documentation/IRQ-domain.txt +++ b/Documentation/IRQ-domain.txt @@ -32,9 +32,9 @@ top of the irq_alloc_desc*() API. An irq_domain to manage mapping is preferred over interrupt controller drivers open coding their own reverse mapping scheme. -irq_domain also implements translation from Device Tree interrupt -specifiers to hwirq numbers, and can be easily extended to support -other IRQ topology data sources. +irq_domain also implements translation from an abstract irq_fwspec +structure to hwirq numbers (Device Tree and ACPI GSI so far), and can +be easily extended to support other IRQ topology data sources. === irq_domain usage === An interrupt controller driver creates and registers an irq_domain by @@ -184,7 +184,7 @@ There are four major interfaces to use hierarchy irq_domain: related resources associated with these interrupts. 3) irq_domain_activate_irq(): activate interrupt controller hardware to deliver the interrupt. -3) irq_domain_deactivate_irq(): deactivate interrupt controller hardware +4) irq_domain_deactivate_irq(): deactivate interrupt controller hardware to stop delivering the interrupt. Following changes are needed to support hierarchy irq_domain. diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 2b3340ae915d..d5e5c5bef28c 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -5,9 +5,10 @@ * helpful for interrupt controllers to implement mapping between hardware * irq numbers and the Linux irq number space. * - * irq_domains also have a hook for translating device tree interrupt - * representation into a hardware irq number that can be mapped back to a - * Linux irq number without any extra platform support code. + * irq_domains also have hooks for translating device tree or other + * firmware interrupt representations into a hardware irq number that + * can be mapped back to a Linux irq number without any extra platform + * support code. * * Interrupt controller "domain" data structure. This could be defined as a * irq domain controller. That is, it handles the mapping between hardware @@ -17,16 +18,12 @@ * model). It's the domain callbacks that are responsible for setting the * irq_chip on a given irq_desc after it's been mapped. * - * The host code and data structures are agnostic to whether or not - * we use an open firmware device-tree. We do have references to struct - * device_node in two places: in irq_find_host() to find the host matching - * a given interrupt controller node, and of course as an argument to its - * counterpart domain->ops->match() callback. However, those are treated as - * generic pointers by the core and the fact that it's actually a device-node - * pointer is purely a convention between callers and implementation. This - * code could thus be used on other architectures by replacing those two - * by some sort of arch-specific void * "token" used to identify interrupt - * controllers. + * The host code and data structures use a fwnode_handle pointer to + * identify the domain. In some cases, and in order to preserve source + * code compatibility, this fwnode pointer is "upgraded" to a DT + * device_node. For those firmware infrastructures that do not provide + * a unique identifier for an interrupt controller, the irq_domain + * code offers a fwnode allocator. */ #ifndef _LINUX_IRQDOMAIN_H |