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 #include <linux/irq.h>
   6
   7 /*
   8  * Device resource management aware IRQ request/free implementation.
   9  */
  10 struct irq_devres {
  11         unsigned int irq;
  12         void *dev_id;
  13 };
  14
  15 static void devm_irq_release(struct device *dev, void *res)
  16 {
  17         struct irq_devres *this = res;
  18
  19         free_irq(this->irq, this->dev_id);
  20 }
  21
  22 static int devm_irq_match(struct device *dev, void *res, void *data)
  23 {
  24         struct irq_devres *this = res, *match = data;
  25
  26         return this->irq == match->irq && this->dev_id == match->dev_id;
  27 }
  28
  29 /**
  30  *      devm_request_threaded_irq - allocate an interrupt line for a managed device
  31  *      @dev: device to request interrupt for
  32  *      @irq: Interrupt line to allocate
  33  *      @handler: Function to be called when the IRQ occurs
  34  *      @thread_fn: function to be called in a threaded interrupt context. NULL
  35  *                  for devices which handle everything in @handler
  36  *      @irqflags: Interrupt type flags
  37  *      @devname: An ascii name for the claiming device, dev_name(dev) if NULL
  38  *      @dev_id: A cookie passed back to the handler function
  39  *
  40  *      Except for the extra @dev argument, this function takes the
  41  *      same arguments and performs the same function as
  42  *      request_threaded_irq().  IRQs requested with this function will be
  43  *      automatically freed on driver detach.
  44  *
  45  *      If an IRQ allocated with this function needs to be freed
  46  *      separately, devm_free_irq() must be used.
  47  */
  48 int devm_request_threaded_irq(struct device *dev, unsigned int irq,
  49                               irq_handler_t handler, irq_handler_t thread_fn,
  50                               unsigned long irqflags, const char *devname,
  51                               void *dev_id)
  52 {
  53         struct irq_devres *dr;
  54         int rc;
  55
  56         dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
  57                           GFP_KERNEL);
  58         if (!dr)
  59                 return -ENOMEM;
  60
  61         if (!devname)
  62                 devname = dev_name(dev);
  63
  64         rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
  65                                   dev_id);
  66         if (rc) {
  67                 devres_free(dr);
  68                 return rc;
  69         }
  70
  71         dr->irq = irq;
  72         dr->dev_id = dev_id;
  73         devres_add(dev, dr);
  74
  75         return 0;
  76 }
  77 EXPORT_SYMBOL(devm_request_threaded_irq);
  78
  79 /**
  80  *      devm_request_any_context_irq - allocate an interrupt line for a managed device
  81  *      @dev: device to request interrupt for
  82  *      @irq: Interrupt line to allocate
  83  *      @handler: Function to be called when the IRQ occurs
  84  *      @thread_fn: function to be called in a threaded interrupt context. NULL
  85  *                  for devices which handle everything in @handler
  86  *      @irqflags: Interrupt type flags
  87  *      @devname: An ascii name for the claiming device, dev_name(dev) if NULL
  88  *      @dev_id: A cookie passed back to the handler function
  89  *
  90  *      Except for the extra @dev argument, this function takes the
  91  *      same arguments and performs the same function as
  92  *      request_any_context_irq().  IRQs requested with this function will be
  93  *      automatically freed on driver detach.
  94  *
  95  *      If an IRQ allocated with this function needs to be freed
  96  *      separately, devm_free_irq() must be used.
  97  */
  98 int devm_request_any_context_irq(struct device *dev, unsigned int irq,
  99                               irq_handler_t handler, unsigned long irqflags,
 100                               const char *devname, void *dev_id)
 101 {
 102         struct irq_devres *dr;
 103         int rc;
 104
 105         dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
 106                           GFP_KERNEL);
 107         if (!dr)
 108                 return -ENOMEM;
 109
 110         if (!devname)
 111                 devname = dev_name(dev);
 112
 113         rc = request_any_context_irq(irq, handler, irqflags, devname, dev_id);
 114         if (rc < 0) {
 115                 devres_free(dr);
 116                 return rc;
 117         }
 118
 119         dr->irq = irq;
 120         dr->dev_id = dev_id;
 121         devres_add(dev, dr);
 122
 123         return rc;
 124 }
 125 EXPORT_SYMBOL(devm_request_any_context_irq);
 126
 127 /**
 128  *      devm_free_irq - free an interrupt
 129  *      @dev: device to free interrupt for
 130  *      @irq: Interrupt line to free
 131  *      @dev_id: Device identity to free
 132  *
 133  *      Except for the extra @dev argument, this function takes the
 134  *      same arguments and performs the same function as free_irq().
 135  *      This function instead of free_irq() should be used to manually
 136  *      free IRQs allocated with devm_request_irq().
 137  */
 138 void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
 139 {
 140         struct irq_devres match_data = { irq, dev_id };
 141
 142         WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
 143                                &match_data));
 144         free_irq(irq, dev_id);
 145 }
 146 EXPORT_SYMBOL(devm_free_irq);
 147
 148 struct irq_desc_devres {
 149         unsigned int from;
 150         unsigned int cnt;
 151 };
 152
 153 static void devm_irq_desc_release(struct device *dev, void *res)
 154 {
 155         struct irq_desc_devres *this = res;
 156
 157         irq_free_descs(this->from, this->cnt);
 158 }
 159
 160 /**
 161  * __devm_irq_alloc_descs - Allocate and initialize a range of irq descriptors
 162  *                          for a managed device
 163  * @dev:        Device to allocate the descriptors for
 164  * @irq:        Allocate for specific irq number if irq >= 0
 165  * @from:       Start the search from this irq number
 166  * @cnt:        Number of consecutive irqs to allocate
 167  * @node:       Preferred node on which the irq descriptor should be allocated
 168  * @owner:      Owning module (can be NULL)
 169  * @affinity:   Optional pointer to an affinity mask array of size @cnt
 170  *              which hints where the irq descriptors should be allocated
 171  *              and which default affinities to use
 172  *
 173  * Returns the first irq number or error code.
 174  *
 175  * Note: Use the provided wrappers (devm_irq_alloc_desc*) for simplicity.
 176  */
 177 int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from,
 178                            unsigned int cnt, int node, struct module *owner,
 179                            const struct cpumask *affinity)
 180 {
 181         struct irq_desc_devres *dr;
 182         int base;
 183
 184         dr = devres_alloc(devm_irq_desc_release, sizeof(*dr), GFP_KERNEL);
 185         if (!dr)
 186                 return -ENOMEM;
 187
 188         base = __irq_alloc_descs(irq, from, cnt, node, owner, affinity);
 189         if (base < 0) {
 190                 devres_free(dr);
 191                 return base;
 192         }
 193
 194         dr->from = base;
 195         dr->cnt = cnt;
 196         devres_add(dev, dr);
 197
 198         return base;
 199 }
 200 EXPORT_SYMBOL_GPL(__devm_irq_alloc_descs);