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 */
26static 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 */
54struct 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 */
71void 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 */
83static 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 */
115static 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
131static 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 */
151int 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 */
170void rio_unregister_driver(struct rio_driver *rdrv)
171{
172	driver_unregister(&rdrv->driver);
173}
174
175void rio_attach_device(struct rio_dev *rdev)
176{
177	rdev->dev.bus = &rio_bus_type;
178}
179EXPORT_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 */
191static 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
209static 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
226struct class rio_mport_class = {
227	.name		= "rapidio_port",
228	.owner		= THIS_MODULE,
229	.dev_groups	= rio_mport_groups,
230};
231EXPORT_SYMBOL_GPL(rio_mport_class);
232
233struct 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 */
250static 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
263postcore_initcall(rio_bus_init);
264
265EXPORT_SYMBOL_GPL(rio_register_driver);
266EXPORT_SYMBOL_GPL(rio_unregister_driver);
267EXPORT_SYMBOL_GPL(rio_bus_type);
268EXPORT_SYMBOL_GPL(rio_dev_get);
269EXPORT_SYMBOL_GPL(rio_dev_put);
270