LXR linux/kernel/irq/devres.c

   1#include <linux/module.h>
   2#include <linux/interrupt.h>
   3#include <linux/device.h>
   4#include <linux/gfp.h>
   5
   6/*
   7 * Device resource management aware IRQ request/free implementation.
   8 */
   9struct irq_devres {
  10        unsigned int irq;
  11        void *dev_id;
  12};
  13
  14static void devm_irq_release(struct device *dev, void *res)
  15{
  16        struct irq_devres *this = res;
  17
  18        free_irq(this->irq, this->dev_id);
  19}
  20
  21static int devm_irq_match(struct device *dev, void *res, void *data)
  22{
  23        struct irq_devres *this = res, *match = data;
  24
  25        return this->irq == match->irq && this->dev_id == match->dev_id;
  26}
  27
  28/**
  29 *      devm_request_irq - allocate an interrupt line for a managed device
  30 *      @dev: device to request interrupt for
  31 *      @irq: Interrupt line to allocate
  32 *      @handler: Function to be called when the IRQ occurs
  33 *      @irqflags: Interrupt type flags
  34 *      @devname: An ascii name for the claiming device
  35 *      @dev_id: A cookie passed back to the handler function
  36 *
  37 *      Except for the extra @dev argument, this function takes the
  38 *      same arguments and performs the same function as
  39 *      request_irq().  IRQs requested with this function will be
  40 *      automatically freed on driver detach.
  41 *
  42 *      If an IRQ allocated with this function needs to be freed
  43 *      separately, dev_free_irq() must be used.
  44 */
  45int devm_request_irq(struct device *dev, unsigned int irq,
  46                     irq_handler_t handler, unsigned long irqflags,
  47                     const char *devname, void *dev_id)
  48{
  49        struct irq_devres *dr;
  50        int rc;
  51
  52        dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
  53                          GFP_KERNEL);
  54        if (!dr)
  55                return -ENOMEM;
  56
  57        rc = request_irq(irq, handler, irqflags, devname, dev_id);
  58        if (rc) {
  59                devres_free(dr);
  60                return rc;
  61        }
  62
  63        dr->irq = irq;
  64        dr->dev_id = dev_id;
  65        devres_add(dev, dr);
  66
  67        return 0;
  68}
  69EXPORT_SYMBOL(devm_request_irq);
  70
  71/**
  72 *      devm_free_irq - free an interrupt
  73 *      @dev: device to free interrupt for
  74 *      @irq: Interrupt line to free
  75 *      @dev_id: Device identity to free
  76 *
  77 *      Except for the extra @dev argument, this function takes the
  78 *      same arguments and performs the same function as free_irq().
  79 *      This function instead of free_irq() should be used to manually
  80 *      free IRQs allocated with dev_request_irq().
  81 */
  82void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
  83{
  84        struct irq_devres match_data = { irq, dev_id };
  85
  86        free_irq(irq, dev_id);
  87        WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
  88                               &match_data));
  89}
  90EXPORT_SYMBOL(devm_free_irq);
  91