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  */
   9 struct irq_devres {
  10         unsigned int irq;
  11         void *dev_id;
  12 };
  13
  14 static 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
  21 static 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_threaded_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  *      @thread_fn: function to be called in a threaded interrupt context. NULL
  34  *                  for devices which handle everything in @handler
  35  *      @irqflags: Interrupt type flags
  36  *      @devname: An ascii name for the claiming device
  37  *      @dev_id: A cookie passed back to the handler function
  38  *
  39  *      Except for the extra @dev argument, this function takes the
  40  *      same arguments and performs the same function as
  41  *      request_irq().  IRQs requested with this function will be
  42  *      automatically freed on driver detach.
  43  *
  44  *      If an IRQ allocated with this function needs to be freed
  45  *      separately, devm_free_irq() must be used.
  46  */
  47 int devm_request_threaded_irq(struct device *dev, unsigned int irq,
  48                               irq_handler_t handler, irq_handler_t thread_fn,
  49                               unsigned long irqflags, const char *devname,
  50                               void *dev_id)
  51 {
  52         struct irq_devres *dr;
  53         int rc;
  54
  55         dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
  56                           GFP_KERNEL);
  57         if (!dr)
  58                 return -ENOMEM;
  59
  60         rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
  61                                   dev_id);
  62         if (rc) {
  63                 devres_free(dr);
  64                 return rc;
  65         }
  66
  67         dr->irq = irq;
  68         dr->dev_id = dev_id;
  69         devres_add(dev, dr);
  70
  71         return 0;
  72 }
  73 EXPORT_SYMBOL(devm_request_threaded_irq);
  74
  75 /**
  76  *      devm_request_any_context_irq - allocate an interrupt line for a managed device
  77  *      @dev: device to request interrupt for
  78  *      @irq: Interrupt line to allocate
  79  *      @handler: Function to be called when the IRQ occurs
  80  *      @thread_fn: function to be called in a threaded interrupt context. NULL
  81  *                  for devices which handle everything in @handler
  82  *      @irqflags: Interrupt type flags
  83  *      @devname: An ascii name for the claiming device
  84  *      @dev_id: A cookie passed back to the handler function
  85  *
  86  *      Except for the extra @dev argument, this function takes the
  87  *      same arguments and performs the same function as
  88  *      request_any_context_irq().  IRQs requested with this function will be
  89  *      automatically freed on driver detach.
  90  *
  91  *      If an IRQ allocated with this function needs to be freed
  92  *      separately, devm_free_irq() must be used.
  93  */
  94 int devm_request_any_context_irq(struct device *dev, unsigned int irq,
  95                               irq_handler_t handler, unsigned long irqflags,
  96                               const char *devname, void *dev_id)
  97 {
  98         struct irq_devres *dr;
  99         int rc;
 100
 101         dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
 102                           GFP_KERNEL);
 103         if (!dr)
 104                 return -ENOMEM;
 105
 106         rc = request_any_context_irq(irq, handler, irqflags, devname, dev_id);
 107         if (rc) {
 108                 devres_free(dr);
 109                 return rc;
 110         }
 111
 112         dr->irq = irq;
 113         dr->dev_id = dev_id;
 114         devres_add(dev, dr);
 115
 116         return 0;
 117 }
 118 EXPORT_SYMBOL(devm_request_any_context_irq);
 119
 120 /**
 121  *      devm_free_irq - free an interrupt
 122  *      @dev: device to free interrupt for
 123  *      @irq: Interrupt line to free
 124  *      @dev_id: Device identity to free
 125  *
 126  *      Except for the extra @dev argument, this function takes the
 127  *      same arguments and performs the same function as free_irq().
 128  *      This function instead of free_irq() should be used to manually
 129  *      free IRQs allocated with devm_request_irq().
 130  */
 131 void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
 132 {
 133         struct irq_devres match_data = { irq, dev_id };
 134
 135         WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
 136                                &match_data));
 137         free_irq(irq, dev_id);
 138 }
 139 EXPORT_SYMBOL(devm_free_irq);