xref: /linux/kernel/irq/irqdomain.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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 	if (d->nr_irq && ((intspec[0] < d->hwirq_base) ||
139 	    (intspec[0] >= d->hwirq_base + d->nr_irq)))
140 		return -EINVAL;
141 
142 	*out_hwirq = intspec[0];
143 	*out_type = IRQ_TYPE_NONE;
144 	if (intsize > 1)
145 		*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
146 	return 0;
147 }
148 
149 /**
150  * irq_domain_create_simple() - Set up a 'simple' translation range
151  */
152 void irq_domain_add_simple(struct device_node *controller, int irq_base)
153 {
154 	struct irq_domain *domain;
155 
156 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
157 	if (!domain) {
158 		WARN_ON(1);
159 		return;
160 	}
161 
162 	domain->irq_base = irq_base;
163 	domain->of_node = of_node_get(controller);
164 	domain->ops = &irq_domain_simple_ops;
165 	irq_domain_add(domain);
166 }
167 EXPORT_SYMBOL_GPL(irq_domain_add_simple);
168 
169 void irq_domain_generate_simple(const struct of_device_id *match,
170 				u64 phys_base, unsigned int irq_start)
171 {
172 	struct device_node *node;
173 	pr_info("looking for phys_base=%llx, irq_start=%i\n",
174 		(unsigned long long) phys_base, (int) irq_start);
175 	node = of_find_matching_node_by_address(NULL, match, phys_base);
176 	if (node)
177 		irq_domain_add_simple(node, irq_start);
178 	else
179 		pr_info("no node found\n");
180 }
181 EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
182 #endif /* CONFIG_OF_IRQ */
183 
184 struct irq_domain_ops irq_domain_simple_ops = {
185 #ifdef CONFIG_OF_IRQ
186 	.dt_translate = irq_domain_simple_dt_translate,
187 #endif /* CONFIG_OF_IRQ */
188 };
189 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
190