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