xref: /openbmc/linux/drivers/pnp/driver.c (revision 9b93eb47)
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(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 
72 void pnp_device_detach(struct pnp_dev *pnp_dev)
73 {
74 	mutex_lock(&pnp_lock);
75 	if (pnp_dev->status == PNP_ATTACHED)
76 		pnp_dev->status = PNP_READY;
77 	mutex_unlock(&pnp_lock);
78 }
79 
80 static int pnp_device_probe(struct device *dev)
81 {
82 	int error;
83 	struct pnp_driver *pnp_drv;
84 	struct pnp_dev *pnp_dev;
85 	const struct pnp_device_id *dev_id = NULL;
86 	pnp_dev = to_pnp_dev(dev);
87 	pnp_drv = to_pnp_driver(dev->driver);
88 
89 	error = pnp_device_attach(pnp_dev);
90 	if (error < 0)
91 		return error;
92 
93 	if (pnp_dev->active == 0) {
94 		if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)) {
95 			error = pnp_activate_dev(pnp_dev);
96 			if (error < 0)
97 				return error;
98 		}
99 	} else if ((pnp_drv->flags & PNP_DRIVER_RES_DISABLE)
100 		   == PNP_DRIVER_RES_DISABLE) {
101 		error = pnp_disable_dev(pnp_dev);
102 		if (error < 0)
103 			return error;
104 	}
105 	error = 0;
106 	if (pnp_drv->probe) {
107 		dev_id = match_device(pnp_drv, pnp_dev);
108 		if (dev_id != NULL)
109 			error = pnp_drv->probe(pnp_dev, dev_id);
110 	}
111 	if (error >= 0) {
112 		pnp_dev->driver = pnp_drv;
113 		error = 0;
114 	} else
115 		goto fail;
116 
117 	return error;
118 
119 fail:
120 	pnp_device_detach(pnp_dev);
121 	return error;
122 }
123 
124 static int pnp_device_remove(struct device *dev)
125 {
126 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
127 	struct pnp_driver *drv = pnp_dev->driver;
128 
129 	if (drv) {
130 		if (drv->remove)
131 			drv->remove(pnp_dev);
132 		pnp_dev->driver = NULL;
133 	}
134 
135 	if (pnp_dev->active &&
136 	    (!drv || !(drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)))
137 		pnp_disable_dev(pnp_dev);
138 
139 	pnp_device_detach(pnp_dev);
140 	return 0;
141 }
142 
143 static void pnp_device_shutdown(struct device *dev)
144 {
145 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
146 	struct pnp_driver *drv = pnp_dev->driver;
147 
148 	if (drv && drv->shutdown)
149 		drv->shutdown(pnp_dev);
150 }
151 
152 static int pnp_bus_match(struct device *dev, struct device_driver *drv)
153 {
154 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
155 	struct pnp_driver *pnp_drv = to_pnp_driver(drv);
156 
157 	if (match_device(pnp_drv, pnp_dev) == NULL)
158 		return 0;
159 	return 1;
160 }
161 
162 static int __pnp_bus_suspend(struct device *dev, pm_message_t state)
163 {
164 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
165 	struct pnp_driver *pnp_drv = pnp_dev->driver;
166 	int error;
167 
168 	if (!pnp_drv)
169 		return 0;
170 
171 	if (pnp_drv->driver.pm && pnp_drv->driver.pm->suspend) {
172 		error = pnp_drv->driver.pm->suspend(dev);
173 		suspend_report_result(pnp_drv->driver.pm->suspend, error);
174 		if (error)
175 			return error;
176 	}
177 
178 	if (pnp_drv->suspend) {
179 		error = pnp_drv->suspend(pnp_dev, state);
180 		if (error)
181 			return error;
182 	}
183 
184 	if (pnp_can_disable(pnp_dev)) {
185 		error = pnp_stop_dev(pnp_dev);
186 		if (error)
187 			return error;
188 	}
189 
190 	if (pnp_can_suspend(pnp_dev))
191 		pnp_dev->protocol->suspend(pnp_dev, state);
192 	return 0;
193 }
194 
195 static int pnp_bus_suspend(struct device *dev)
196 {
197 	return __pnp_bus_suspend(dev, PMSG_SUSPEND);
198 }
199 
200 static int pnp_bus_freeze(struct device *dev)
201 {
202 	return __pnp_bus_suspend(dev, PMSG_FREEZE);
203 }
204 
205 static int pnp_bus_poweroff(struct device *dev)
206 {
207 	return __pnp_bus_suspend(dev, PMSG_HIBERNATE);
208 }
209 
210 static int pnp_bus_resume(struct device *dev)
211 {
212 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
213 	struct pnp_driver *pnp_drv = pnp_dev->driver;
214 	int error;
215 
216 	if (!pnp_drv)
217 		return 0;
218 
219 	if (pnp_dev->protocol->resume) {
220 		error = pnp_dev->protocol->resume(pnp_dev);
221 		if (error)
222 			return error;
223 	}
224 
225 	if (pnp_can_write(pnp_dev)) {
226 		error = pnp_start_dev(pnp_dev);
227 		if (error)
228 			return error;
229 	}
230 
231 	if (pnp_drv->driver.pm && pnp_drv->driver.pm->resume) {
232 		error = pnp_drv->driver.pm->resume(dev);
233 		if (error)
234 			return error;
235 	}
236 
237 	if (pnp_drv->resume) {
238 		error = pnp_drv->resume(pnp_dev);
239 		if (error)
240 			return error;
241 	}
242 
243 	return 0;
244 }
245 
246 static const struct dev_pm_ops pnp_bus_dev_pm_ops = {
247 	/* Suspend callbacks */
248 	.suspend = pnp_bus_suspend,
249 	.resume = pnp_bus_resume,
250 	/* Hibernate callbacks */
251 	.freeze = pnp_bus_freeze,
252 	.thaw = pnp_bus_resume,
253 	.poweroff = pnp_bus_poweroff,
254 	.restore = pnp_bus_resume,
255 };
256 
257 struct bus_type pnp_bus_type = {
258 	.name    = "pnp",
259 	.match   = pnp_bus_match,
260 	.probe   = pnp_device_probe,
261 	.remove  = pnp_device_remove,
262 	.shutdown = pnp_device_shutdown,
263 	.pm	 = &pnp_bus_dev_pm_ops,
264 	.dev_groups = pnp_dev_groups,
265 };
266 
267 int pnp_register_driver(struct pnp_driver *drv)
268 {
269 	drv->driver.name = drv->name;
270 	drv->driver.bus = &pnp_bus_type;
271 
272 	return driver_register(&drv->driver);
273 }
274 
275 void pnp_unregister_driver(struct pnp_driver *drv)
276 {
277 	driver_unregister(&drv->driver);
278 }
279 
280 /**
281  * pnp_add_id - adds an EISA id to the specified device
282  * @dev: pointer to the desired device
283  * @id: pointer to an EISA id string
284  */
285 struct pnp_id *pnp_add_id(struct pnp_dev *dev, const char *id)
286 {
287 	struct pnp_id *dev_id, *ptr;
288 
289 	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
290 	if (!dev_id)
291 		return NULL;
292 
293 	dev_id->id[0] = id[0];
294 	dev_id->id[1] = id[1];
295 	dev_id->id[2] = id[2];
296 	dev_id->id[3] = tolower(id[3]);
297 	dev_id->id[4] = tolower(id[4]);
298 	dev_id->id[5] = tolower(id[5]);
299 	dev_id->id[6] = tolower(id[6]);
300 	dev_id->id[7] = '\0';
301 
302 	dev_id->next = NULL;
303 	ptr = dev->id;
304 	while (ptr && ptr->next)
305 		ptr = ptr->next;
306 	if (ptr)
307 		ptr->next = dev_id;
308 	else
309 		dev->id = dev_id;
310 
311 	return dev_id;
312 }
313 
314 EXPORT_SYMBOL(pnp_register_driver);
315 EXPORT_SYMBOL(pnp_unregister_driver);
316 EXPORT_SYMBOL(pnp_device_attach);
317 EXPORT_SYMBOL(pnp_device_detach);
318