xref: /linux/drivers/rapidio/rio-driver.c (revision 409c38d4f156740bf3165fd6ceae4fa6425eebf4)
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 void 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 
129 static void rio_device_shutdown(struct device *dev)
130 {
131 	struct rio_dev *rdev = to_rio_dev(dev);
132 	struct rio_driver *rdrv = rdev->driver;
133 
134 	dev_dbg(dev, "RIO: %s\n", __func__);
135 
136 	if (rdrv && rdrv->shutdown)
137 		rdrv->shutdown(rdev);
138 }
139 
140 /**
141  *  rio_register_driver - register a new RIO driver
142  *  @rdrv: the RIO driver structure to register
143  *
144  *  Adds a &struct rio_driver to the list of registered drivers.
145  *  Returns a negative value on error, otherwise 0. If no error
146  *  occurred, the driver remains registered even if no device
147  *  was claimed during registration.
148  */
149 int rio_register_driver(struct rio_driver *rdrv)
150 {
151 	/* initialize common driver fields */
152 	rdrv->driver.name = rdrv->name;
153 	rdrv->driver.bus = &rio_bus_type;
154 
155 	/* register with core */
156 	return driver_register(&rdrv->driver);
157 }
158 
159 /**
160  *  rio_unregister_driver - unregister a RIO driver
161  *  @rdrv: the RIO driver structure to unregister
162  *
163  *  Deletes the &struct rio_driver from the list of registered RIO
164  *  drivers, gives it a chance to clean up by calling its remove()
165  *  function for each device it was responsible for, and marks those
166  *  devices as driverless.
167  */
168 void rio_unregister_driver(struct rio_driver *rdrv)
169 {
170 	driver_unregister(&rdrv->driver);
171 }
172 
173 void rio_attach_device(struct rio_dev *rdev)
174 {
175 	rdev->dev.bus = &rio_bus_type;
176 }
177 EXPORT_SYMBOL_GPL(rio_attach_device);
178 
179 /**
180  *  rio_match_bus - Tell if a RIO device structure has a matching RIO driver device id structure
181  *  @dev: the standard device structure to match against
182  *  @drv: the standard driver structure containing the ids to match against
183  *
184  *  Used by a driver to check whether a RIO device present in the
185  *  system is in its list of supported devices. Returns 1 if
186  *  there is a matching &struct rio_device_id or 0 if there is
187  *  no match.
188  */
189 static int rio_match_bus(struct device *dev, struct device_driver *drv)
190 {
191 	struct rio_dev *rdev = to_rio_dev(dev);
192 	struct rio_driver *rdrv = to_rio_driver(drv);
193 	const struct rio_device_id *id = rdrv->id_table;
194 	const struct rio_device_id *found_id;
195 
196 	if (!id)
197 		goto out;
198 
199 	found_id = rio_match_device(id, rdev);
200 
201 	if (found_id)
202 		return 1;
203 
204       out:return 0;
205 }
206 
207 static int rio_uevent(const struct device *dev, struct kobj_uevent_env *env)
208 {
209 	const struct rio_dev *rdev;
210 
211 	if (!dev)
212 		return -ENODEV;
213 
214 	rdev = to_rio_dev(dev);
215 	if (!rdev)
216 		return -ENODEV;
217 
218 	if (add_uevent_var(env, "MODALIAS=rapidio:v%04Xd%04Xav%04Xad%04X",
219 			   rdev->vid, rdev->did, rdev->asm_vid, rdev->asm_did))
220 		return -ENOMEM;
221 	return 0;
222 }
223 
224 struct class rio_mport_class = {
225 	.name		= "rapidio_port",
226 	.dev_groups	= rio_mport_groups,
227 };
228 EXPORT_SYMBOL_GPL(rio_mport_class);
229 
230 struct bus_type rio_bus_type = {
231 	.name = "rapidio",
232 	.match = rio_match_bus,
233 	.dev_groups = rio_dev_groups,
234 	.bus_groups = rio_bus_groups,
235 	.probe = rio_device_probe,
236 	.remove = rio_device_remove,
237 	.shutdown = rio_device_shutdown,
238 	.uevent	= rio_uevent,
239 };
240 
241 /**
242  *  rio_bus_init - Register the RapidIO bus with the device model
243  *
244  *  Registers the RIO mport device class and RIO bus type with the Linux
245  *  device model.
246  */
247 static int __init rio_bus_init(void)
248 {
249 	int ret;
250 
251 	ret = class_register(&rio_mport_class);
252 	if (!ret) {
253 		ret = bus_register(&rio_bus_type);
254 		if (ret)
255 			class_unregister(&rio_mport_class);
256 	}
257 	return ret;
258 }
259 
260 postcore_initcall(rio_bus_init);
261 
262 EXPORT_SYMBOL_GPL(rio_register_driver);
263 EXPORT_SYMBOL_GPL(rio_unregister_driver);
264 EXPORT_SYMBOL_GPL(rio_bus_type);
265 EXPORT_SYMBOL_GPL(rio_dev_get);
266 EXPORT_SYMBOL_GPL(rio_dev_put);
267