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path: root/drivers/of/irq.c
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-rw-r--r--drivers/of/irq.c107
1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 6a5b5e777dd2..6d3dd3988d0f 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -19,10 +19,12 @@
*/
#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>
/* 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);
+ }
+}