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1 #-
2 # Copyright (c) 1998-2004 Doug Rabson
3 # All rights reserved.
4 #
5 # Redistribution and use in source and binary forms, with or without
6 # modification, are permitted provided that the following conditions
7 # are met:
8 # 1. Redistributions of source code must retain the above copyright
9 # notice, this list of conditions and the following disclaimer.
10 # 2. Redistributions in binary form must reproduce the above copyright
11 # notice, this list of conditions and the following disclaimer in the
12 # documentation and/or other materials provided with the distribution.
13 #
14 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 # SUCH DAMAGE.
25 #
26 # $FreeBSD$
27 #
29 #include <sys/bus.h>
31 /**
32 * @defgroup DEVICE device - KObj methods for all device drivers
33 * @brief A basic set of methods required for all device drivers.
34 *
35 * The device interface is used to match devices to drivers during
36 * autoconfiguration and provides methods to allow drivers to handle
37 * system-wide events such as suspend, resume or shutdown.
38 * @{
39 */
40 INTERFACE device;
42 #
43 # Default implementations of some methods.
44 #
45 CODE {
46 static int null_shutdown(device_t dev)
47 {
48 return 0;
49 }
51 static int null_suspend(device_t dev)
52 {
53 return 0;
54 }
56 static int null_resume(device_t dev)
57 {
58 return 0;
59 }
61 static int null_quiesce(device_t dev)
62 {
63 return EOPNOTSUPP;
64 }
65 };
67 /**
68 * @brief Probe to see if a device matches a driver.
69 *
70 * Users should not call this method directly. Normally, this
71 * is called via device_probe_and_attach() to select a driver
72 * calling the DEVICE_PROBE() of all candidate drivers and attach
73 * the winning driver (if any) to the device.
74 *
75 * This function is used to match devices to device drivers.
76 * Typically, the driver will examine the device to see if
77 * it is suitable for this driver. This might include checking
78 * the values of various device instance variables or reading
79 * hardware registers.
80 *
81 * In some cases, there may be more than one driver available
82 * which can be used for a device (for instance there might
83 * be a generic driver which works for a set of many types of
84 * device and a more specific driver which works for a subset
85 * of devices). Because of this, a driver should not assume
86 * that it will be the driver that attaches to the device even
87 * if it returns a success status from DEVICE_PROBE(). In particular,
88 * a driver must free any resources which it allocated during
89 * the probe before returning. The return value of DEVICE_PROBE()
90 * is used to elect which driver is used - the driver which returns
91 * the largest non-error value wins the election and attaches to
92 * the device.
93 *
94 * If a driver matches the hardware, it should set the device
95 * description string using device_set_desc() or
96 * device_set_desc_copy(). This string is
97 * used to generate an informative message when DEVICE_ATTACH()
98 * is called.
99 *
100 * As a special case, if a driver returns zero, the driver election
101 * is cut short and that driver will attach to the device
102 * immediately.
103 *
104 * For example, a probe method for a pci device driver might look
105 * like this:
106 *
107 * @code
108 * int foo_probe(device_t dev)
109 * {
110 * if (pci_get_vendor(dev) == FOOVENDOR &&
111 * pci_get_device(dev) == FOODEVICE) {
112 * device_set_desc(dev, "Foo device");
113 * return (0);
114 * }
115 * return (ENXIO);
116 * }
117 * @endcode
118 *
119 * To include this method in a device driver, use a line like this
120 * in the driver's method list:
121 *
122 * @code
123 * KOBJMETHOD(device_probe, foo_probe)
124 * @endcode
125 *
126 * @param dev the device to probe
127 *
128 * @retval 0 if the driver strongly matches this device
129 * @retval negative if the driver can match this device - the
130 * least negative value is used to select the
131 * driver
132 * @retval ENXIO if the driver does not match the device
133 * @retval positive if some kind of error was detected during
134 * the probe, a regular unix error code should
135 * be returned to indicate the type of error
136 * @see DEVICE_ATTACH(), pci_get_vendor(), pci_get_device()
137 */
138 METHOD int probe {
139 device_t dev;
140 };
142 /**
143 * @brief Allow a device driver to detect devices not otherwise enumerated.
144 *
145 * The DEVICE_IDENTIFY() method is used by some drivers (e.g. the ISA
146 * bus driver) to help populate the bus device with a useful set of
147 * child devices, normally by calling the BUS_ADD_CHILD() method of
148 * the parent device. For instance, the ISA bus driver uses several
149 * special drivers, including the isahint driver and the pnp driver to
150 * create child devices based on configuration hints and PnP bus
151 * probes respectively.
152 *
153 * Many bus drivers which support true plug-and-play do not need to
154 * use this method at all since child devices can be discovered
155 * automatically without help from child drivers.
156 *
157 * To include this method in a device driver, use a line like this
158 * in the driver's method list:
159 *
160 * @code
161 * KOBJMETHOD(device_identify, foo_identify)
162 * @endcode
163 *
164 * @param driver the driver whose identify method is being called
165 * @param parent the parent device to use when adding new children
166 */
167 STATICMETHOD void identify {
168 driver_t *driver;
169 device_t parent;
170 };
172 /**
173 * @brief Attach a device to a device driver
174 *
175 * Normally only called via device_probe_and_attach(), this is called
176 * when a driver has succeeded in probing against a device.
177 * This method should initialise the hardware and allocate other
178 * system resources (e.g. devfs entries) as required.
179 *
180 * To include this method in a device driver, use a line like this
181 * in the driver's method list:
182 *
183 * @code
184 * KOBJMETHOD(device_attach, foo_attach)
185 * @endcode
186 *
187 * @param dev the device to probe
188 *
189 * @retval 0 success
190 * @retval non-zero if some kind of error was detected during
191 * the attach, a regular unix error code should
192 * be returned to indicate the type of error
193 * @see DEVICE_PROBE()
194 */
195 METHOD int attach {
196 device_t dev;
197 };
199 /**
200 * @brief Detach a driver from a device.
201 *
202 * This can be called if the user is replacing the
203 * driver software or if a device is about to be physically removed
204 * from the system (e.g. for removable hardware such as USB or PCCARD).
205 *
206 * To include this method in a device driver, use a line like this
207 * in the driver's method list:
208 *
209 * @code
210 * KOBJMETHOD(device_detach, foo_detach)
211 * @endcode
212 *
213 * @param dev the device to detach
214 *
215 * @retval 0 success
216 * @retval non-zero the detach could not be performed, e.g. if the
217 * driver does not support detaching.
218 *
219 * @see DEVICE_ATTACH()
220 */
221 METHOD int detach {
222 device_t dev;
223 };
225 /**
226 * @brief Called during system shutdown.
227 *
228 * This method allows drivers to detect when the system is being shut down.
229 * Some drivers need to use this to place their hardware in a consistent
230 * state before rebooting the computer.
231 *
232 * To include this method in a device driver, use a line like this
233 * in the driver's method list:
234 *
235 * @code
236 * KOBJMETHOD(device_shutdown, foo_shutdown)
237 * @endcode
238 */
239 METHOD int shutdown {
240 device_t dev;
241 } DEFAULT null_shutdown;
243 /**
244 * @brief This is called by the power-management subsystem when a
245 * suspend has been requested by the user or by some automatic
246 * mechanism.
247 *
248 * This gives drivers a chance to veto the suspend or save their
249 * configuration before power is removed.
250 *
251 * To include this method in a device driver, use a line like this in
252 * the driver's method list:
253 *
254 * @code
255 * KOBJMETHOD(device_suspend, foo_suspend)
256 * @endcode
257 *
258 * @param dev the device being suspended
259 *
260 * @retval 0 success
261 * @retval non-zero an error occurred while attempting to prepare the
262 * device for suspension
263 *
264 * @see DEVICE_RESUME()
265 */
266 METHOD int suspend {
267 device_t dev;
268 } DEFAULT null_suspend;
270 /**
271 * @brief This is called when the system resumes after a suspend.
272 *
273 * To include this method in a device driver, use a line like this
274 * in the driver's method list:
275 *
276 * @code
277 * KOBJMETHOD(device_resume, foo_resume)
278 * @endcode
279 *
280 * @param dev the device being resumed
281 *
282 * @retval 0 success
283 * @retval non-zero an error occurred while attempting to restore the
284 * device from suspension
285 *
286 * @see DEVICE_SUSPEND()
287 */
288 METHOD int resume {
289 device_t dev;
290 } DEFAULT null_resume;
292 /**
293 * @brief This is called when the driver is asked to quiesce itself.
294 *
295 * The driver should arrange for the orderly shutdown of this device.
296 * All further access to the device should be curtailed. Soon there
297 * will be a request to detach, but there won't necessarily be one.
298 *
299 * To include this method in a device driver, use a line like this
300 * in the driver's method list:
301 *
302 * @code
303 * KOBJMETHOD(device_quiesce, foo_quiesce)
304 * @endcode
305 *
306 * @param dev the device being quiesced
307 *
308 * @retval 0 success
309 * @retval non-zero an error occurred while attempting to quiesce the
310 * device
311 *
312 * @see DEVICE_DETACH()
313 */
314 METHOD int quiesce {
315 device_t dev;
316 } DEFAULT null_quiesce;