xref: /linux/drivers/dio/dio-driver.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  *  DIO Driver Services
3  *
4  *  Copyright (C) 2004 Jochen Friedrich
5  *
6  *  Loosely based on drivers/pci/pci-driver.c and drivers/zorro/zorro-driver.c
7  *
8  *  This file is subject to the terms and conditions of the GNU General Public
9  *  License.  See the file COPYING in the main directory of this archive
10  *  for more details.
11  */
12 
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/dio.h>
16 
17 
18 	/**
19 	 *  dio_match_device - Tell if a DIO device structure has a matching
20 	 *                     DIO device id structure
21 	 *  @ids: array of DIO device id structures to search in
22 	 *  @dev: the DIO device structure to match against
23 	 *
24 	 *  Used by a driver to check whether a DIO device present in the
25 	 *  system is in its list of supported devices. Returns the matching
26 	 *  dio_device_id structure or %NULL if there is no match.
27 	 */
28 
29 const struct dio_device_id *
30 dio_match_device(const struct dio_device_id *ids,
31 		   const struct dio_dev *d)
32 {
33 	while (ids->id) {
34 		if (ids->id == DIO_WILDCARD)
35 			return ids;
36 		if (DIO_NEEDSSECID(ids->id & 0xff)) {
37 			if (ids->id == d->id)
38 				return ids;
39 		} else {
40 			if ((ids->id & 0xff) == (d->id & 0xff))
41 				return ids;
42 		}
43 		ids++;
44 	}
45 	return NULL;
46 }
47 
48 static int dio_device_probe(struct device *dev)
49 {
50 	int error = 0;
51 	struct dio_driver *drv = to_dio_driver(dev->driver);
52 	struct dio_dev *d = to_dio_dev(dev);
53 
54 	if (!d->driver && drv->probe) {
55 		const struct dio_device_id *id;
56 
57 		id = dio_match_device(drv->id_table, d);
58 		if (id)
59 			error = drv->probe(d, id);
60 		if (error >= 0) {
61 			d->driver = drv;
62 			error = 0;
63 		}
64 	}
65 	return error;
66 }
67 
68 
69 	/**
70 	 *  dio_register_driver - register a new DIO driver
71 	 *  @drv: the driver structure to register
72 	 *
73 	 *  Adds the driver structure to the list of registered drivers
74 	 *  Returns zero or a negative error value.
75 	 */
76 
77 int dio_register_driver(struct dio_driver *drv)
78 {
79 	/* initialize common driver fields */
80 	drv->driver.name = drv->name;
81 	drv->driver.bus = &dio_bus_type;
82 
83 	/* register with core */
84 	return driver_register(&drv->driver);
85 }
86 
87 
88 	/**
89 	 *  dio_unregister_driver - unregister a DIO driver
90 	 *  @drv: the driver structure to unregister
91 	 *
92 	 *  Deletes the driver structure from the list of registered DIO drivers,
93 	 *  gives it a chance to clean up by calling its remove() function for
94 	 *  each device it was responsible for, and marks those devices as
95 	 *  driverless.
96 	 */
97 
98 void dio_unregister_driver(struct dio_driver *drv)
99 {
100 	driver_unregister(&drv->driver);
101 }
102 
103 
104 	/**
105 	 *  dio_bus_match - Tell if a DIO device structure has a matching DIO
106 	 *                  device id structure
107 	 *  @ids: array of DIO device id structures to search in
108 	 *  @dev: the DIO device structure to match against
109 	 *
110 	 *  Used by a driver to check whether a DIO device present in the
111 	 *  system is in its list of supported devices. Returns the matching
112 	 *  dio_device_id structure or %NULL if there is no match.
113 	 */
114 
115 static int dio_bus_match(struct device *dev, struct device_driver *drv)
116 {
117 	struct dio_dev *d = to_dio_dev(dev);
118 	struct dio_driver *dio_drv = to_dio_driver(drv);
119 	const struct dio_device_id *ids = dio_drv->id_table;
120 
121 	if (!ids)
122 		return 0;
123 
124 	while (ids->id) {
125 		if (ids->id == DIO_WILDCARD)
126 			return 1;
127 		if (DIO_NEEDSSECID(ids->id & 0xff)) {
128 			if (ids->id == d->id)
129 				return 1;
130 		} else {
131 			if ((ids->id & 0xff) == (d->id & 0xff))
132 				return 1;
133 		}
134 		ids++;
135 	}
136 	return 0;
137 }
138 
139 
140 struct bus_type dio_bus_type = {
141 	.name	= "dio",
142 	.match	= dio_bus_match,
143 	.probe	= dio_device_probe,
144 };
145 
146 
147 static int __init dio_driver_init(void)
148 {
149 	return bus_register(&dio_bus_type);
150 }
151 
152 postcore_initcall(dio_driver_init);
153 
154 EXPORT_SYMBOL(dio_match_device);
155 EXPORT_SYMBOL(dio_register_driver);
156 EXPORT_SYMBOL(dio_unregister_driver);
157 EXPORT_SYMBOL(dio_dev_driver);
158 EXPORT_SYMBOL(dio_bus_type);
159