kernel/irq/irqdomain.c

   1 #include <linux/irq.h>
   2 #include <linux/irqdomain.h>
   3 #include <linux/module.h>
   4 #include <linux/mutex.h>
   5 #include <linux/of.h>
   6 #include <linux/of_address.h>
   7 #include <linux/slab.h>
   8
   9 static LIST_HEAD(irq_domain_list);
  10 static DEFINE_MUTEX(irq_domain_mutex);
  11
  12 /**
  13  * irq_domain_add() - Register an irq_domain
  14  * @domain: ptr to initialized irq_domain structure
  15  *
  16  * Registers an irq_domain structure.  The irq_domain must at a minimum be
  17  * initialized with an ops structure pointer, and either a ->to_irq hook or
  18  * a valid irq_base value.  Everything else is optional.
  19  */
  20 void irq_domain_add(struct irq_domain *domain)
  21 {
  22         struct irq_data *d;
  23         int hwirq, irq;
  24
  25         /*
  26          * This assumes that the irq_domain owner has already allocated
  27          * the irq_descs.  This block will be removed when support for dynamic
  28          * allocation of irq_descs is added to irq_domain.
  29          */
  30         irq_domain_for_each_irq(domain, hwirq, irq) {
  31                 d = irq_get_irq_data(irq);
  32                 if (!d) {
  33                         WARN(1, "error: assigning domain to non existant irq_desc");
  34                         return;
  35                 }
  36                 if (d->domain) {
  37                         /* things are broken; just report, don't clean up */
  38                         WARN(1, "error: irq_desc already assigned to a domain");
  39                         return;
  40                 }
  41                 d->domain = domain;
  42                 d->hwirq = hwirq;
  43         }
  44
  45         mutex_lock(&irq_domain_mutex);
  46         list_add(&domain->list, &irq_domain_list);
  47         mutex_unlock(&irq_domain_mutex);
  48 }
  49
  50 /**
  51  * irq_domain_del() - Unregister an irq_domain
  52  * @domain: ptr to registered irq_domain.
  53  */
  54 void irq_domain_del(struct irq_domain *domain)
  55 {
  56         struct irq_data *d;
  57         int hwirq, irq;
  58
  59         mutex_lock(&irq_domain_mutex);
  60         list_del(&domain->list);
  61         mutex_unlock(&irq_domain_mutex);
  62
  63         /* Clear the irq_domain assignments */
  64         irq_domain_for_each_irq(domain, hwirq, irq) {
  65                 d = irq_get_irq_data(irq);
  66                 d->domain = NULL;
  67         }
  68 }
  69
  70 #if defined(CONFIG_OF_IRQ)
  71 /**
  72  * irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
  73  *
  74  * Used by the device tree interrupt mapping code to translate a device tree
  75  * interrupt specifier to a valid linux irq number.  Returns either a valid
  76  * linux IRQ number or 0.
  77  *
  78  * When the caller no longer need the irq number returned by this function it
  79  * should arrange to call irq_dispose_mapping().
  80  */
  81 unsigned int irq_create_of_mapping(struct device_node *controller,
  82                                    const u32 *intspec, unsigned int intsize)
  83 {
  84         struct irq_domain *domain;
  85         unsigned long hwirq;
  86         unsigned int irq, type;
  87         int rc = -EINVAL;
  88
  89         /* Find a domain which can translate the irq spec */
  90         mutex_lock(&irq_domain_mutex);
  91         list_for_each_entry(domain, &irq_domain_list, list) {
  92                 if (!domain->ops->dt_translate)
  93                         continue;
  94                 rc = domain->ops->dt_translate(domain, controller,
  95                                         intspec, intsize, &hwirq, &type);
  96                 if (rc == 0)
  97                         break;
  98         }
  99         mutex_unlock(&irq_domain_mutex);
 100
 101         if (rc != 0)
 102                 return 0;
 103
 104         irq = irq_domain_to_irq(domain, hwirq);
 105         if (type != IRQ_TYPE_NONE)
 106                 irq_set_irq_type(irq, type);
 107         pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
 108                  controller->full_name, (int)hwirq, irq, type);
 109         return irq;
 110 }
 111 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
 112
 113 /**
 114  * irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
 115  * @irq: linux irq number to be discarded
 116  *
 117  * Calling this function indicates the caller no longer needs a reference to
 118  * the linux irq number returned by a prior call to irq_create_of_mapping().
 119  */
 120 void irq_dispose_mapping(unsigned int irq)
 121 {
 122         /*
 123          * nothing yet; will be filled when support for dynamic allocation of
 124          * irq_descs is added to irq_domain
 125          */
 126 }
 127 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 128
 129 int irq_domain_simple_dt_translate(struct irq_domain *d,
 130                             struct device_node *controller,
 131                             const u32 *intspec, unsigned int intsize,
 132                             unsigned long *out_hwirq, unsigned int *out_type)
 133 {
 134         if (d->of_node != controller)
 135                 return -EINVAL;
 136         if (intsize < 1)
 137                 return -EINVAL;
 138
 139         *out_hwirq = intspec[0];
 140         *out_type = IRQ_TYPE_NONE;
 141         if (intsize > 1)
 142                 *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
 143         return 0;
 144 }
 145
 146 struct irq_domain_ops irq_domain_simple_ops = {
 147         .dt_translate = irq_domain_simple_dt_translate,
 148 };
 149 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
 150
 151 /**
 152  * irq_domain_create_simple() - Set up a 'simple' translation range
 153  */
 154 void irq_domain_add_simple(struct device_node *controller, int irq_base)
 155 {
 156         struct irq_domain *domain;
 157
 158         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 159         if (!domain) {
 160                 WARN_ON(1);
 161                 return;
 162         }
 163
 164         domain->irq_base = irq_base;
 165         domain->of_node = of_node_get(controller);
 166         domain->ops = &irq_domain_simple_ops;
 167         irq_domain_add(domain);
 168 }
 169 EXPORT_SYMBOL_GPL(irq_domain_add_simple);
 170
 171 void irq_domain_generate_simple(const struct of_device_id *match,
 172                                 u64 phys_base, unsigned int irq_start)
 173 {
 174         struct device_node *node;
 175         pr_info("looking for phys_base=%llx, irq_start=%i\n",
 176                 (unsigned long long) phys_base, (int) irq_start);
 177         node = of_find_matching_node_by_address(NULL, match, phys_base);
 178         if (node)
 179                 irq_domain_add_simple(node, irq_start);
 180         else
 181                 pr_info("no node found\n");
 182 }
 183 EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
 184 #endif /* CONFIG_OF_IRQ */