xref: /linux/drivers/pnp/driver.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * driver.c - device id matching, driver model, etc.
4  *
5  * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
6  */
7 
8 #include <linux/string.h>
9 #include <linux/list.h>
10 #include <linux/module.h>
11 #include <linux/ctype.h>
12 #include <linux/slab.h>
13 #include <linux/pnp.h>
14 #include "base.h"
15 
16 static int compare_func(const char *ida, const char *idb)
17 {
18 	int i;
19 
20 	/* we only need to compare the last 4 chars */
21 	for (i = 3; i < 7; i++) {
22 		if (ida[i] != 'X' &&
23 		    idb[i] != 'X' && toupper(ida[i]) != toupper(idb[i]))
24 			return 0;
25 	}
26 	return 1;
27 }
28 
29 int compare_pnp_id(struct pnp_id *pos, const char *id)
30 {
31 	if (!pos || !id || (strlen(id) != 7))
32 		return 0;
33 	if (memcmp(id, "ANYDEVS", 7) == 0)
34 		return 1;
35 	while (pos) {
36 		if (memcmp(pos->id, id, 3) == 0)
37 			if (compare_func(pos->id, id) == 1)
38 				return 1;
39 		pos = pos->next;
40 	}
41 	return 0;
42 }
43 
44 static const struct pnp_device_id *match_device(const struct pnp_driver *drv,
45 						struct pnp_dev *dev)
46 {
47 	const struct pnp_device_id *drv_id = drv->id_table;
48 
49 	if (!drv_id)
50 		return NULL;
51 
52 	while (*drv_id->id) {
53 		if (compare_pnp_id(dev->id, drv_id->id))
54 			return drv_id;
55 		drv_id++;
56 	}
57 	return NULL;
58 }
59 
60 int pnp_device_attach(struct pnp_dev *pnp_dev)
61 {
62 	mutex_lock(&pnp_lock);
63 	if (pnp_dev->status != PNP_READY) {
64 		mutex_unlock(&pnp_lock);
65 		return -EBUSY;
66 	}
67 	pnp_dev->status = PNP_ATTACHED;
68 	mutex_unlock(&pnp_lock);
69 	return 0;
70 }
71 EXPORT_SYMBOL(pnp_device_attach);
72 
73 void pnp_device_detach(struct pnp_dev *pnp_dev)
74 {
75 	mutex_lock(&pnp_lock);
76 	if (pnp_dev->status == PNP_ATTACHED)
77 		pnp_dev->status = PNP_READY;
78 	mutex_unlock(&pnp_lock);
79 }
80 EXPORT_SYMBOL(pnp_device_detach);
81 
82 static int pnp_device_probe(struct device *dev)
83 {
84 	int error;
85 	struct pnp_driver *pnp_drv;
86 	struct pnp_dev *pnp_dev;
87 	const struct pnp_device_id *dev_id = NULL;
88 	pnp_dev = to_pnp_dev(dev);
89 	pnp_drv = to_pnp_driver(dev->driver);
90 
91 	error = pnp_device_attach(pnp_dev);
92 	if (error < 0)
93 		return error;
94 
95 	if (pnp_dev->active == 0) {
96 		if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)) {
97 			error = pnp_activate_dev(pnp_dev);
98 			if (error < 0)
99 				return error;
100 		}
101 	} else if ((pnp_drv->flags & PNP_DRIVER_RES_DISABLE)
102 		   == PNP_DRIVER_RES_DISABLE) {
103 		error = pnp_disable_dev(pnp_dev);
104 		if (error < 0)
105 			return error;
106 	}
107 	error = 0;
108 	if (pnp_drv->probe) {
109 		dev_id = match_device(pnp_drv, pnp_dev);
110 		if (dev_id != NULL)
111 			error = pnp_drv->probe(pnp_dev, dev_id);
112 	}
113 	if (error >= 0) {
114 		pnp_dev->driver = pnp_drv;
115 		error = 0;
116 	} else
117 		goto fail;
118 
119 	return error;
120 
121 fail:
122 	pnp_device_detach(pnp_dev);
123 	return error;
124 }
125 
126 static void pnp_device_remove(struct device *dev)
127 {
128 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
129 	struct pnp_driver *drv = pnp_dev->driver;
130 
131 	if (drv) {
132 		if (drv->remove)
133 			drv->remove(pnp_dev);
134 		pnp_dev->driver = NULL;
135 	}
136 
137 	if (pnp_dev->active &&
138 	    (!drv || !(drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)))
139 		pnp_disable_dev(pnp_dev);
140 
141 	pnp_device_detach(pnp_dev);
142 }
143 
144 static void pnp_device_shutdown(struct device *dev)
145 {
146 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
147 	struct pnp_driver *drv = pnp_dev->driver;
148 
149 	if (drv && drv->shutdown)
150 		drv->shutdown(pnp_dev);
151 }
152 
153 static int pnp_uevent(const struct device *dev, struct kobj_uevent_env *env)
154 {
155 	struct pnp_id *pos;
156 	const struct pnp_dev *pnp_dev = to_pnp_dev(dev);
157 
158 	if (!dev)
159 		return -ENODEV;
160 
161 	pos = pnp_dev->id;
162 	while (pos) {
163 		if (add_uevent_var(env, "MODALIAS=pnp:d%s", pos->id))
164 			return -ENOMEM;
165 		pos = pos->next;
166 	}
167 
168 	return 0;
169 }
170 
171 static int pnp_bus_match(struct device *dev, const struct device_driver *drv)
172 {
173 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
174 	const struct pnp_driver *pnp_drv = to_pnp_driver(drv);
175 
176 	if (match_device(pnp_drv, pnp_dev) == NULL)
177 		return 0;
178 	return 1;
179 }
180 
181 static int __pnp_bus_suspend(struct device *dev, pm_message_t state)
182 {
183 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
184 	struct pnp_driver *pnp_drv = pnp_dev->driver;
185 	int error;
186 
187 	if (!pnp_drv)
188 		return 0;
189 
190 	if (pnp_drv->driver.pm && pnp_drv->driver.pm->suspend) {
191 		error = pnp_drv->driver.pm->suspend(dev);
192 		suspend_report_result(dev, pnp_drv->driver.pm->suspend, error);
193 		if (error)
194 			return error;
195 	}
196 
197 	if (pnp_drv->suspend) {
198 		error = pnp_drv->suspend(pnp_dev, state);
199 		if (error)
200 			return error;
201 	}
202 
203 	/* can_write is necessary to be able to re-start the device on resume */
204 	if (pnp_can_disable(pnp_dev) && pnp_can_write(pnp_dev)) {
205 		error = pnp_stop_dev(pnp_dev);
206 		if (error)
207 			return error;
208 	}
209 
210 	if (pnp_can_suspend(pnp_dev))
211 		pnp_dev->protocol->suspend(pnp_dev, state);
212 	return 0;
213 }
214 
215 static int pnp_bus_suspend(struct device *dev)
216 {
217 	return __pnp_bus_suspend(dev, PMSG_SUSPEND);
218 }
219 
220 static int pnp_bus_freeze(struct device *dev)
221 {
222 	return __pnp_bus_suspend(dev, PMSG_FREEZE);
223 }
224 
225 static int pnp_bus_poweroff(struct device *dev)
226 {
227 	return __pnp_bus_suspend(dev, PMSG_HIBERNATE);
228 }
229 
230 static int pnp_bus_resume(struct device *dev)
231 {
232 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
233 	struct pnp_driver *pnp_drv = pnp_dev->driver;
234 	int error;
235 
236 	if (!pnp_drv)
237 		return 0;
238 
239 	if (pnp_dev->protocol->resume) {
240 		error = pnp_dev->protocol->resume(pnp_dev);
241 		if (error)
242 			return error;
243 	}
244 
245 	if (pnp_can_write(pnp_dev)) {
246 		error = pnp_start_dev(pnp_dev);
247 		if (error)
248 			return error;
249 	}
250 
251 	if (pnp_drv->driver.pm && pnp_drv->driver.pm->resume) {
252 		error = pnp_drv->driver.pm->resume(dev);
253 		if (error)
254 			return error;
255 	}
256 
257 	if (pnp_drv->resume) {
258 		error = pnp_drv->resume(pnp_dev);
259 		if (error)
260 			return error;
261 	}
262 
263 	return 0;
264 }
265 
266 static const struct dev_pm_ops pnp_bus_dev_pm_ops = {
267 	/* Suspend callbacks */
268 	.suspend = pnp_bus_suspend,
269 	.resume = pnp_bus_resume,
270 	/* Hibernate callbacks */
271 	.freeze = pnp_bus_freeze,
272 	.thaw = pnp_bus_resume,
273 	.poweroff = pnp_bus_poweroff,
274 	.restore = pnp_bus_resume,
275 };
276 
277 const struct bus_type pnp_bus_type = {
278 	.name    = "pnp",
279 	.match   = pnp_bus_match,
280 	.uevent  = pnp_uevent,
281 	.probe   = pnp_device_probe,
282 	.remove  = pnp_device_remove,
283 	.shutdown = pnp_device_shutdown,
284 	.pm	 = &pnp_bus_dev_pm_ops,
285 	.dev_groups = pnp_dev_groups,
286 };
287 
288 bool dev_is_pnp(const struct device *dev)
289 {
290 	return dev->bus == &pnp_bus_type;
291 }
292 EXPORT_SYMBOL_GPL(dev_is_pnp);
293 
294 int pnp_register_driver(struct pnp_driver *drv)
295 {
296 	drv->driver.name = drv->name;
297 	drv->driver.bus = &pnp_bus_type;
298 
299 	return driver_register(&drv->driver);
300 }
301 EXPORT_SYMBOL(pnp_register_driver);
302 
303 void pnp_unregister_driver(struct pnp_driver *drv)
304 {
305 	driver_unregister(&drv->driver);
306 }
307 EXPORT_SYMBOL(pnp_unregister_driver);
308 
309 /**
310  * pnp_add_id - adds an EISA id to the specified device
311  * @dev: pointer to the desired device
312  * @id: pointer to an EISA id string
313  */
314 struct pnp_id *pnp_add_id(struct pnp_dev *dev, const char *id)
315 {
316 	struct pnp_id *dev_id, *ptr;
317 
318 	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
319 	if (!dev_id)
320 		return NULL;
321 
322 	dev_id->id[0] = id[0];
323 	dev_id->id[1] = id[1];
324 	dev_id->id[2] = id[2];
325 	dev_id->id[3] = tolower(id[3]);
326 	dev_id->id[4] = tolower(id[4]);
327 	dev_id->id[5] = tolower(id[5]);
328 	dev_id->id[6] = tolower(id[6]);
329 	dev_id->id[7] = '\0';
330 
331 	dev_id->next = NULL;
332 	ptr = dev->id;
333 	while (ptr && ptr->next)
334 		ptr = ptr->next;
335 	if (ptr)
336 		ptr->next = dev_id;
337 	else
338 		dev->id = dev_id;
339 
340 	return dev_id;
341 }
342