diff --git a/drivers/of/irq.c b/drivers/of/irq.c index 9f689f1da0fc..791270b8bd1c 100644 --- a/drivers/of/irq.c +++ b/drivers/of/irq.c @@ -19,10 +19,12 @@ */ #include +#include #include #include #include #include +#include /* For archs that don't support NO_IRQ (such as x86), provide a dummy value */ #ifndef NO_IRQ @@ -386,3 +388,108 @@ int of_irq_to_resource_table(struct device_node *dev, struct resource *res, return i; } + +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)) + 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); + 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 = 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(&intc_parent_list, typeof(*desc), list); + if (list_empty(&intc_parent_list) || !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); + } +} diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h index cd2e61ce4e83..d0307eed20c9 100644 --- a/include/linux/of_irq.h +++ b/include/linux/of_irq.h @@ -33,6 +33,8 @@ struct of_irq { u32 specifier[OF_MAX_IRQ_SPEC]; /* Specifier copy */ }; +typedef int (*of_irq_init_cb_t)(struct device_node *, struct device_node *); + /* * Workarounds only applied to 32bit powermac machines */ @@ -73,6 +75,7 @@ extern int of_irq_to_resource_table(struct device_node *dev, struct resource *res, int nr_irqs); extern struct device_node *of_irq_find_parent(struct device_node *child); +extern void of_irq_init(const struct of_device_id *matches); #endif /* CONFIG_OF_IRQ */ #endif /* CONFIG_OF */