xref: /openbmc/linux/kernel/irq/devres.c (revision bb0eb050)
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);
201