driver.c

  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
 16static 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
 29int 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
 44static 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
 60int 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}
 71EXPORT_SYMBOL(pnp_device_attach);
 72
 73void 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}
 80EXPORT_SYMBOL(pnp_device_detach);
 81
 82static 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
121fail:
122	pnp_device_detach(pnp_dev);
123	return error;
124}
125
126static 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
144static 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
153static 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
171static 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
181static 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
215static int pnp_bus_suspend(struct device *dev)
216{
217	return __pnp_bus_suspend(dev, PMSG_SUSPEND);
218}
219
220static int pnp_bus_freeze(struct device *dev)
221{
222	return __pnp_bus_suspend(dev, PMSG_FREEZE);
223}
224
225static int pnp_bus_poweroff(struct device *dev)
226{
227	return __pnp_bus_suspend(dev, PMSG_HIBERNATE);
228}
229
230static 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
266static 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
277const 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
288bool dev_is_pnp(const struct device *dev)
289{
290	return dev->bus == &pnp_bus_type;
291}
292EXPORT_SYMBOL_GPL(dev_is_pnp);
293
294int 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}
301EXPORT_SYMBOL(pnp_register_driver);
302
303void pnp_unregister_driver(struct pnp_driver *drv)
304{
305	driver_unregister(&drv->driver);
306}
307EXPORT_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 */
314struct 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}