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-rw-r--r--kernel/irq/devres.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
new file mode 100644
index 00000000000..85a430da0fb
--- /dev/null
+++ b/kernel/irq/devres.c
@@ -0,0 +1,88 @@
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+/*
+ * Device resource management aware IRQ request/free implementation.
+ */
+struct irq_devres {
+ unsigned int irq;
+ void *dev_id;
+};
+
+static void devm_irq_release(struct device *dev, void *res)
+{
+ struct irq_devres *this = res;
+
+ free_irq(this->irq, this->dev_id);
+}
+
+static int devm_irq_match(struct device *dev, void *res, void *data)
+{
+ struct irq_devres *this = res, *match = data;
+
+ return this->irq == match->irq && this->dev_id == match->dev_id;
+}
+
+/**
+ * devm_request_irq - allocate an interrupt line for a managed device
+ * @dev: device to request interrupt for
+ * @irq: Interrupt line to allocate
+ * @handler: Function to be called when the IRQ occurs
+ * @irqflags: Interrupt type flags
+ * @devname: An ascii name for the claiming device
+ * @dev_id: A cookie passed back to the handler function
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as
+ * request_irq(). IRQs requested with this function will be
+ * automatically freed on driver detach.
+ *
+ * If an IRQ allocated with this function needs to be freed
+ * separately, dev_free_irq() must be used.
+ */
+int devm_request_irq(struct device *dev, unsigned int irq,
+ irq_handler_t handler, unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ struct irq_devres *dr;
+ int rc;
+
+ dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
+ GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ rc = request_irq(irq, handler, irqflags, devname, dev_id);
+ if (rc) {
+ kfree(dr);
+ return rc;
+ }
+
+ dr->irq = irq;
+ dr->dev_id = dev_id;
+ devres_add(dev, dr);
+
+ return 0;
+}
+EXPORT_SYMBOL(devm_request_irq);
+
+/**
+ * devm_free_irq - free an interrupt
+ * @dev: device to free interrupt for
+ * @irq: Interrupt line to free
+ * @dev_id: Device identity to free
+ *
+ * Except for the extra @dev argument, this function takes the
+ * same arguments and performs the same function as free_irq().
+ * This function instead of free_irq() should be used to manually
+ * free IRQs allocated with dev_request_irq().
+ */
+void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
+{
+ struct irq_devres match_data = { irq, dev_id };
+
+ free_irq(irq, dev_id);
+ WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
+ &match_data));
+}
+EXPORT_SYMBOL(devm_free_irq);