xref: /linux/drivers/rapidio/rio-driver.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * RapidIO driver support
4  *
5  * Copyright 2005 MontaVista Software, Inc.
6  * Matt Porter <mporter@kernel.crashing.org>
7  */
8 
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/rio.h>
12 #include <linux/rio_ids.h>
13 #include <linux/rio_drv.h>
14 
15 #include "rio.h"
16 
17 /**
18  *  rio_match_device - Tell if a RIO device has a matching RIO device id structure
19  *  @id: the RIO device id structure to match against
20  *  @rdev: the RIO device structure to match against
21  *
22  *  Used from driver probe and bus matching to check whether a RIO device
23  *  matches a device id structure provided by a RIO driver. Returns the
24  *  matching &struct rio_device_id or %NULL if there is no match.
25  */
26 static const struct rio_device_id *rio_match_device(const struct rio_device_id
27 						    *id,
28 						    const struct rio_dev *rdev)
29 {
30 	while (id->vid || id->asm_vid) {
31 		if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
32 		    ((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
33 		    ((id->asm_vid == RIO_ANY_ID)
34 		     || (id->asm_vid == rdev->asm_vid))
35 		    && ((id->asm_did == RIO_ANY_ID)
36 			|| (id->asm_did == rdev->asm_did)))
37 			return id;
38 		id++;
39 	}
40 	return NULL;
41 }
42 
43 /**
44  * rio_dev_get - Increments the reference count of the RIO device structure
45  *
46  * @rdev: RIO device being referenced
47  *
48  * Each live reference to a device should be refcounted.
49  *
50  * Drivers for RIO devices should normally record such references in
51  * their probe() methods, when they bind to a device, and release
52  * them by calling rio_dev_put(), in their disconnect() methods.
53  */
54 struct rio_dev *rio_dev_get(struct rio_dev *rdev)
55 {
56 	if (rdev)
57 		get_device(&rdev->dev);
58 
59 	return rdev;
60 }
61 
62 /**
63  * rio_dev_put - Release a use of the RIO device structure
64  *
65  * @rdev: RIO device being disconnected
66  *
67  * Must be called when a user of a device is finished with it.
68  * When the last user of the device calls this function, the
69  * memory of the device is freed.
70  */
71 void rio_dev_put(struct rio_dev *rdev)
72 {
73 	if (rdev)
74 		put_device(&rdev->dev);
75 }
76 
77 /**
78  *  rio_device_probe - Tell if a RIO device structure has a matching RIO device id structure
79  *  @dev: the RIO device structure to match against
80  *
81  * return 0 and set rio_dev->driver when drv claims rio_dev, else error
82  */
83 static int rio_device_probe(struct device *dev)
84 {
85 	struct rio_driver *rdrv = to_rio_driver(dev->driver);
86 	struct rio_dev *rdev = to_rio_dev(dev);
87 	int error = -ENODEV;
88 	const struct rio_device_id *id;
89 
90 	if (!rdev->driver && rdrv->probe) {
91 		if (!rdrv->id_table)
92 			return error;
93 		id = rio_match_device(rdrv->id_table, rdev);
94 		rio_dev_get(rdev);
95 		if (id)
96 			error = rdrv->probe(rdev, id);
97 		if (error >= 0) {
98 			rdev->driver = rdrv;
99 			error = 0;
100 		} else
101 			rio_dev_put(rdev);
102 	}
103 	return error;
104 }
105 
106 /**
107  *  rio_device_remove - Remove a RIO device from the system
108  *
109  *  @dev: the RIO device structure to match against
110  *
111  * Remove a RIO device from the system. If it has an associated
112  * driver, then run the driver remove() method.  Then update
113  * the reference count.
114  */
115 static int rio_device_remove(struct device *dev)
116 {
117 	struct rio_dev *rdev = to_rio_dev(dev);
118 	struct rio_driver *rdrv = rdev->driver;
119 
120 	if (rdrv) {
121 		if (rdrv->remove)
122 			rdrv->remove(rdev);
123 		rdev->driver = NULL;
124 	}
125 
126 	rio_dev_put(rdev);
127 
128 	return 0;
129 }
130 
131 static void rio_device_shutdown(struct device *dev)
132 {
133 	struct rio_dev *rdev = to_rio_dev(dev);
134 	struct rio_driver *rdrv = rdev->driver;
135 
136 	dev_dbg(dev, "RIO: %s\n", __func__);
137 
138 	if (rdrv && rdrv->shutdown)
139 		rdrv->shutdown(rdev);
140 }
141 
142 /**
143  *  rio_register_driver - register a new RIO driver
144  *  @rdrv: the RIO driver structure to register
145  *
146  *  Adds a &struct rio_driver to the list of registered drivers.
147  *  Returns a negative value on error, otherwise 0. If no error
148  *  occurred, the driver remains registered even if no device
149  *  was claimed during registration.
150  */
151 int rio_register_driver(struct rio_driver *rdrv)
152 {
153 	/* initialize common driver fields */
154 	rdrv->driver.name = rdrv->name;
155 	rdrv->driver.bus = &rio_bus_type;
156 
157 	/* register with core */
158 	return driver_register(&rdrv->driver);
159 }
160 
161 /**
162  *  rio_unregister_driver - unregister a RIO driver
163  *  @rdrv: the RIO driver structure to unregister
164  *
165  *  Deletes the &struct rio_driver from the list of registered RIO
166  *  drivers, gives it a chance to clean up by calling its remove()
167  *  function for each device it was responsible for, and marks those
168  *  devices as driverless.
169  */
170 void rio_unregister_driver(struct rio_driver *rdrv)
171 {
172 	driver_unregister(&rdrv->driver);
173 }
174 
175 void rio_attach_device(struct rio_dev *rdev)
176 {
177 	rdev->dev.bus = &rio_bus_type;
178 }
179 EXPORT_SYMBOL_GPL(rio_attach_device);
180 
181 /**
182  *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
183  *  @dev: the standard device structure to match against
184  *  @drv: the standard driver structure containing the ids to match against
185  *
186  *  Used by a driver to check whether a RIO device present in the
187  *  system is in its list of supported devices. Returns 1 if
188  *  there is a matching &struct rio_device_id or 0 if there is
189  *  no match.
190  */
191 static int rio_match_bus(struct device *dev, struct device_driver *drv)
192 {
193 	struct rio_dev *rdev = to_rio_dev(dev);
194 	struct rio_driver *rdrv = to_rio_driver(drv);
195 	const struct rio_device_id *id = rdrv->id_table;
196 	const struct rio_device_id *found_id;
197 
198 	if (!id)
199 		goto out;
200 
201 	found_id = rio_match_device(id, rdev);
202 
203 	if (found_id)
204 		return 1;
205 
206       out:return 0;
207 }
208 
209 static int rio_uevent(struct device *dev, struct kobj_uevent_env *env)
210 {
211 	struct rio_dev *rdev;
212 
213 	if (!dev)
214 		return -ENODEV;
215 
216 	rdev = to_rio_dev(dev);
217 	if (!rdev)
218 		return -ENODEV;
219 
220 	if (add_uevent_var(env, "MODALIAS=rapidio:v%04Xd%04Xav%04Xad%04X",
221 			   rdev->vid, rdev->did, rdev->asm_vid, rdev->asm_did))
222 		return -ENOMEM;
223 	return 0;
224 }
225 
226 struct class rio_mport_class = {
227 	.name		= "rapidio_port",
228 	.owner		= THIS_MODULE,
229 	.dev_groups	= rio_mport_groups,
230 };
231 EXPORT_SYMBOL_GPL(rio_mport_class);
232 
233 struct bus_type rio_bus_type = {
234 	.name = "rapidio",
235 	.match = rio_match_bus,
236 	.dev_groups = rio_dev_groups,
237 	.bus_groups = rio_bus_groups,
238 	.probe = rio_device_probe,
239 	.remove = rio_device_remove,
240 	.shutdown = rio_device_shutdown,
241 	.uevent	= rio_uevent,
242 };
243 
244 /**
245  *  rio_bus_init - Register the RapidIO bus with the device model
246  *
247  *  Registers the RIO mport device class and RIO bus type with the Linux
248  *  device model.
249  */
250 static int __init rio_bus_init(void)
251 {
252 	int ret;
253 
254 	ret = class_register(&rio_mport_class);
255 	if (!ret) {
256 		ret = bus_register(&rio_bus_type);
257 		if (ret)
258 			class_unregister(&rio_mport_class);
259 	}
260 	return ret;
261 }
262 
263 postcore_initcall(rio_bus_init);
264 
265 EXPORT_SYMBOL_GPL(rio_register_driver);
266 EXPORT_SYMBOL_GPL(rio_unregister_driver);
267 EXPORT_SYMBOL_GPL(rio_bus_type);
268 EXPORT_SYMBOL_GPL(rio_dev_get);
269 EXPORT_SYMBOL_GPL(rio_dev_put);
270