rio-driver.c

  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 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
129static 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 */
149int 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 */
168void rio_unregister_driver(struct rio_driver *rdrv)
169{
170	driver_unregister(&rdrv->driver);
171}
172
173void rio_attach_device(struct rio_dev *rdev)
174{
175	rdev->dev.bus = &rio_bus_type;
176}
177EXPORT_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 */
189static int rio_match_bus(struct device *dev, const struct device_driver *drv)
190{
191	struct rio_dev *rdev = to_rio_dev(dev);
192	const 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
207static 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
224struct class rio_mport_class = {
225	.name		= "rapidio_port",
226	.dev_groups	= rio_mport_groups,
227};
228EXPORT_SYMBOL_GPL(rio_mport_class);
229
230const 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 */
247static 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
260postcore_initcall(rio_bus_init);
261
262EXPORT_SYMBOL_GPL(rio_register_driver);
263EXPORT_SYMBOL_GPL(rio_unregister_driver);
264EXPORT_SYMBOL_GPL(rio_bus_type);
265EXPORT_SYMBOL_GPL(rio_dev_get);
266EXPORT_SYMBOL_GPL(rio_dev_put);