1 files changed, 88 insertions, 0 deletions

diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
new file mode 100644
index 000000000000..85a430da0fb6
--- /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);