xref: /openbmc/linux/kernel/irq/devres.c (revision 2572f00d)
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_threaded_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 < 0) {
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 rc;
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);
140