xref: /openbmc/linux/drivers/rapidio/rio-driver.c (revision b6dcefde)
1 /*
2  * RapidIO driver support
3  *
4  * Copyright 2005 MontaVista Software, Inc.
5  * Matt Porter <mporter@kernel.crashing.org>
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  */
12 
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/rio.h>
16 #include <linux/rio_ids.h>
17 
18 #include "rio.h"
19 
20 /**
21  *  rio_match_device - Tell if a RIO device has a matching RIO device id structure
22  *  @id: the RIO device id structure to match against
23  *  @rdev: the RIO device structure to match against
24  *
25  *  Used from driver probe and bus matching to check whether a RIO device
26  *  matches a device id structure provided by a RIO driver. Returns the
27  *  matching &struct rio_device_id or %NULL if there is no match.
28  */
29 static const struct rio_device_id *rio_match_device(const struct rio_device_id
30 						    *id,
31 						    const struct rio_dev *rdev)
32 {
33 	while (id->vid || id->asm_vid) {
34 		if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
35 		    ((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
36 		    ((id->asm_vid == RIO_ANY_ID)
37 		     || (id->asm_vid == rdev->asm_vid))
38 		    && ((id->asm_did == RIO_ANY_ID)
39 			|| (id->asm_did == rdev->asm_did)))
40 			return id;
41 		id++;
42 	}
43 	return NULL;
44 }
45 
46 /**
47  * rio_dev_get - Increments the reference count of the RIO device structure
48  *
49  * @rdev: RIO device being referenced
50  *
51  * Each live reference to a device should be refcounted.
52  *
53  * Drivers for RIO devices should normally record such references in
54  * their probe() methods, when they bind to a device, and release
55  * them by calling rio_dev_put(), in their disconnect() methods.
56  */
57 struct rio_dev *rio_dev_get(struct rio_dev *rdev)
58 {
59 	if (rdev)
60 		get_device(&rdev->dev);
61 
62 	return rdev;
63 }
64 
65 /**
66  * rio_dev_put - Release a use of the RIO device structure
67  *
68  * @rdev: RIO device being disconnected
69  *
70  * Must be called when a user of a device is finished with it.
71  * When the last user of the device calls this function, the
72  * memory of the device is freed.
73  */
74 void rio_dev_put(struct rio_dev *rdev)
75 {
76 	if (rdev)
77 		put_device(&rdev->dev);
78 }
79 
80 /**
81  *  rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
82  *  @dev: the RIO device structure to match against
83  *
84  * return 0 and set rio_dev->driver when drv claims rio_dev, else error
85  */
86 static int rio_device_probe(struct device *dev)
87 {
88 	struct rio_driver *rdrv = to_rio_driver(dev->driver);
89 	struct rio_dev *rdev = to_rio_dev(dev);
90 	int error = -ENODEV;
91 	const struct rio_device_id *id;
92 
93 	if (!rdev->driver && rdrv->probe) {
94 		if (!rdrv->id_table)
95 			return error;
96 		id = rio_match_device(rdrv->id_table, rdev);
97 		rio_dev_get(rdev);
98 		if (id)
99 			error = rdrv->probe(rdev, id);
100 		if (error >= 0) {
101 			rdev->driver = rdrv;
102 			error = 0;
103 		} else
104 			rio_dev_put(rdev);
105 	}
106 	return error;
107 }
108 
109 /**
110  *  rio_device_remove - Remove a RIO device from the system
111  *
112  *  @dev: the RIO device structure to match against
113  *
114  * Remove a RIO device from the system. If it has an associated
115  * driver, then run the driver remove() method.  Then update
116  * the reference count.
117  */
118 static int rio_device_remove(struct device *dev)
119 {
120 	struct rio_dev *rdev = to_rio_dev(dev);
121 	struct rio_driver *rdrv = rdev->driver;
122 
123 	if (rdrv) {
124 		if (rdrv->remove)
125 			rdrv->remove(rdev);
126 		rdev->driver = NULL;
127 	}
128 
129 	rio_dev_put(rdev);
130 
131 	return 0;
132 }
133 
134 /**
135  *  rio_register_driver - register a new RIO driver
136  *  @rdrv: the RIO driver structure to register
137  *
138  *  Adds a &struct rio_driver to the list of registered drivers.
139  *  Returns a negative value on error, otherwise 0. If no error
140  *  occurred, the driver remains registered even if no device
141  *  was claimed during registration.
142  */
143 int rio_register_driver(struct rio_driver *rdrv)
144 {
145 	/* initialize common driver fields */
146 	rdrv->driver.name = rdrv->name;
147 	rdrv->driver.bus = &rio_bus_type;
148 
149 	/* register with core */
150 	return driver_register(&rdrv->driver);
151 }
152 
153 /**
154  *  rio_unregister_driver - unregister a RIO driver
155  *  @rdrv: the RIO driver structure to unregister
156  *
157  *  Deletes the &struct rio_driver from the list of registered RIO
158  *  drivers, gives it a chance to clean up by calling its remove()
159  *  function for each device it was responsible for, and marks those
160  *  devices as driverless.
161  */
162 void rio_unregister_driver(struct rio_driver *rdrv)
163 {
164 	driver_unregister(&rdrv->driver);
165 }
166 
167 /**
168  *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
169  *  @dev: the standard device structure to match against
170  *  @drv: the standard driver structure containing the ids to match against
171  *
172  *  Used by a driver to check whether a RIO device present in the
173  *  system is in its list of supported devices. Returns 1 if
174  *  there is a matching &struct rio_device_id or 0 if there is
175  *  no match.
176  */
177 static int rio_match_bus(struct device *dev, struct device_driver *drv)
178 {
179 	struct rio_dev *rdev = to_rio_dev(dev);
180 	struct rio_driver *rdrv = to_rio_driver(drv);
181 	const struct rio_device_id *id = rdrv->id_table;
182 	const struct rio_device_id *found_id;
183 
184 	if (!id)
185 		goto out;
186 
187 	found_id = rio_match_device(id, rdev);
188 
189 	if (found_id)
190 		return 1;
191 
192       out:return 0;
193 }
194 
195 static struct device rio_bus = {
196 	.init_name = "rapidio",
197 };
198 
199 struct bus_type rio_bus_type = {
200 	.name = "rapidio",
201 	.match = rio_match_bus,
202 	.dev_attrs = rio_dev_attrs,
203 	.probe = rio_device_probe,
204 	.remove = rio_device_remove,
205 };
206 
207 /**
208  *  rio_bus_init - Register the RapidIO bus with the device model
209  *
210  *  Registers the RIO bus device and RIO bus type with the Linux
211  *  device model.
212  */
213 static int __init rio_bus_init(void)
214 {
215 	if (device_register(&rio_bus) < 0)
216 		printk("RIO: failed to register RIO bus device\n");
217 	return bus_register(&rio_bus_type);
218 }
219 
220 postcore_initcall(rio_bus_init);
221 
222 EXPORT_SYMBOL_GPL(rio_register_driver);
223 EXPORT_SYMBOL_GPL(rio_unregister_driver);
224 EXPORT_SYMBOL_GPL(rio_bus_type);
225 EXPORT_SYMBOL_GPL(rio_dev_get);
226 EXPORT_SYMBOL_GPL(rio_dev_put);
227