xref: /linux/drivers/pcmcia/ds.c (revision 44f57d78)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ds.c -- 16-bit PCMCIA core support
4  *
5  * The initial developer of the original code is David A. Hinds
6  * <dahinds@users.sourceforge.net>.  Portions created by David A. Hinds
7  * are Copyright (C) 1999 David A. Hinds.  All Rights Reserved.
8  *
9  * (C) 1999		David A. Hinds
10  * (C) 2003 - 2010	Dominik Brodowski
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/errno.h>
17 #include <linux/list.h>
18 #include <linux/delay.h>
19 #include <linux/workqueue.h>
20 #include <linux/crc32.h>
21 #include <linux/firmware.h>
22 #include <linux/kref.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/slab.h>
25 
26 #include <pcmcia/cistpl.h>
27 #include <pcmcia/ds.h>
28 #include <pcmcia/ss.h>
29 
30 #include "cs_internal.h"
31 
32 /*====================================================================*/
33 
34 /* Module parameters */
35 
36 MODULE_AUTHOR("David Hinds <dahinds@users.sourceforge.net>");
37 MODULE_DESCRIPTION("PCMCIA Driver Services");
38 MODULE_LICENSE("GPL");
39 
40 
41 /*====================================================================*/
42 
43 static void pcmcia_check_driver(struct pcmcia_driver *p_drv)
44 {
45 	const struct pcmcia_device_id *did = p_drv->id_table;
46 	unsigned int i;
47 	u32 hash;
48 
49 	if (!p_drv->probe || !p_drv->remove)
50 		printk(KERN_DEBUG "pcmcia: %s lacks a requisite callback "
51 		       "function\n", p_drv->name);
52 
53 	while (did && did->match_flags) {
54 		for (i = 0; i < 4; i++) {
55 			if (!did->prod_id[i])
56 				continue;
57 
58 			hash = crc32(0, did->prod_id[i], strlen(did->prod_id[i]));
59 			if (hash == did->prod_id_hash[i])
60 				continue;
61 
62 			printk(KERN_DEBUG "pcmcia: %s: invalid hash for "
63 			       "product string \"%s\": is 0x%x, should "
64 			       "be 0x%x\n", p_drv->name, did->prod_id[i],
65 			       did->prod_id_hash[i], hash);
66 			printk(KERN_DEBUG "pcmcia: see "
67 				"Documentation/pcmcia/devicetable.txt for "
68 				"details\n");
69 		}
70 		did++;
71 	}
72 
73 	return;
74 }
75 
76 
77 /*======================================================================*/
78 
79 
80 struct pcmcia_dynid {
81 	struct list_head		node;
82 	struct pcmcia_device_id		id;
83 };
84 
85 /**
86  * pcmcia_store_new_id - add a new PCMCIA device ID to this driver and re-probe devices
87  * @driver: target device driver
88  * @buf: buffer for scanning device ID data
89  * @count: input size
90  *
91  * Adds a new dynamic PCMCIA device ID to this driver,
92  * and causes the driver to probe for all devices again.
93  */
94 static ssize_t
95 new_id_store(struct device_driver *driver, const char *buf, size_t count)
96 {
97 	struct pcmcia_dynid *dynid;
98 	struct pcmcia_driver *pdrv = to_pcmcia_drv(driver);
99 	__u16 match_flags, manf_id, card_id;
100 	__u8 func_id, function, device_no;
101 	__u32 prod_id_hash[4] = {0, 0, 0, 0};
102 	int fields = 0;
103 	int retval = 0;
104 
105 	fields = sscanf(buf, "%hx %hx %hx %hhx %hhx %hhx %x %x %x %x",
106 			&match_flags, &manf_id, &card_id, &func_id, &function, &device_no,
107 			&prod_id_hash[0], &prod_id_hash[1], &prod_id_hash[2], &prod_id_hash[3]);
108 	if (fields < 6)
109 		return -EINVAL;
110 
111 	dynid = kzalloc(sizeof(struct pcmcia_dynid), GFP_KERNEL);
112 	if (!dynid)
113 		return -ENOMEM;
114 
115 	dynid->id.match_flags = match_flags;
116 	dynid->id.manf_id = manf_id;
117 	dynid->id.card_id = card_id;
118 	dynid->id.func_id = func_id;
119 	dynid->id.function = function;
120 	dynid->id.device_no = device_no;
121 	memcpy(dynid->id.prod_id_hash, prod_id_hash, sizeof(__u32) * 4);
122 
123 	mutex_lock(&pdrv->dynids.lock);
124 	list_add_tail(&dynid->node, &pdrv->dynids.list);
125 	mutex_unlock(&pdrv->dynids.lock);
126 
127 	retval = driver_attach(&pdrv->drv);
128 
129 	if (retval)
130 		return retval;
131 	return count;
132 }
133 static DRIVER_ATTR_WO(new_id);
134 
135 static void
136 pcmcia_free_dynids(struct pcmcia_driver *drv)
137 {
138 	struct pcmcia_dynid *dynid, *n;
139 
140 	mutex_lock(&drv->dynids.lock);
141 	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
142 		list_del(&dynid->node);
143 		kfree(dynid);
144 	}
145 	mutex_unlock(&drv->dynids.lock);
146 }
147 
148 static int
149 pcmcia_create_newid_file(struct pcmcia_driver *drv)
150 {
151 	int error = 0;
152 	if (drv->probe != NULL)
153 		error = driver_create_file(&drv->drv, &driver_attr_new_id);
154 	return error;
155 }
156 
157 static void
158 pcmcia_remove_newid_file(struct pcmcia_driver *drv)
159 {
160 	driver_remove_file(&drv->drv, &driver_attr_new_id);
161 }
162 
163 /**
164  * pcmcia_register_driver - register a PCMCIA driver with the bus core
165  * @driver: the &driver being registered
166  *
167  * Registers a PCMCIA driver with the PCMCIA bus core.
168  */
169 int pcmcia_register_driver(struct pcmcia_driver *driver)
170 {
171 	int error;
172 
173 	if (!driver)
174 		return -EINVAL;
175 
176 	pcmcia_check_driver(driver);
177 
178 	/* initialize common fields */
179 	driver->drv.bus = &pcmcia_bus_type;
180 	driver->drv.owner = driver->owner;
181 	driver->drv.name = driver->name;
182 	mutex_init(&driver->dynids.lock);
183 	INIT_LIST_HEAD(&driver->dynids.list);
184 
185 	pr_debug("registering driver %s\n", driver->name);
186 
187 	error = driver_register(&driver->drv);
188 	if (error < 0)
189 		return error;
190 
191 	error = pcmcia_create_newid_file(driver);
192 	if (error)
193 		driver_unregister(&driver->drv);
194 
195 	return error;
196 }
197 EXPORT_SYMBOL(pcmcia_register_driver);
198 
199 /**
200  * pcmcia_unregister_driver - unregister a PCMCIA driver with the bus core
201  * @driver: the &driver being unregistered
202  */
203 void pcmcia_unregister_driver(struct pcmcia_driver *driver)
204 {
205 	pr_debug("unregistering driver %s\n", driver->name);
206 	pcmcia_remove_newid_file(driver);
207 	driver_unregister(&driver->drv);
208 	pcmcia_free_dynids(driver);
209 }
210 EXPORT_SYMBOL(pcmcia_unregister_driver);
211 
212 
213 /* pcmcia_device handling */
214 
215 static struct pcmcia_device *pcmcia_get_dev(struct pcmcia_device *p_dev)
216 {
217 	struct device *tmp_dev;
218 	tmp_dev = get_device(&p_dev->dev);
219 	if (!tmp_dev)
220 		return NULL;
221 	return to_pcmcia_dev(tmp_dev);
222 }
223 
224 static void pcmcia_put_dev(struct pcmcia_device *p_dev)
225 {
226 	if (p_dev)
227 		put_device(&p_dev->dev);
228 }
229 
230 static void pcmcia_release_function(struct kref *ref)
231 {
232 	struct config_t *c = container_of(ref, struct config_t, ref);
233 	pr_debug("releasing config_t\n");
234 	kfree(c);
235 }
236 
237 static void pcmcia_release_dev(struct device *dev)
238 {
239 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
240 	int i;
241 	dev_dbg(dev, "releasing device\n");
242 	pcmcia_put_socket(p_dev->socket);
243 	for (i = 0; i < 4; i++)
244 		kfree(p_dev->prod_id[i]);
245 	kfree(p_dev->devname);
246 	kref_put(&p_dev->function_config->ref, pcmcia_release_function);
247 	kfree(p_dev);
248 }
249 
250 
251 static int pcmcia_device_probe(struct device *dev)
252 {
253 	struct pcmcia_device *p_dev;
254 	struct pcmcia_driver *p_drv;
255 	struct pcmcia_socket *s;
256 	cistpl_config_t cis_config;
257 	int ret = 0;
258 
259 	dev = get_device(dev);
260 	if (!dev)
261 		return -ENODEV;
262 
263 	p_dev = to_pcmcia_dev(dev);
264 	p_drv = to_pcmcia_drv(dev->driver);
265 	s = p_dev->socket;
266 
267 	dev_dbg(dev, "trying to bind to %s\n", p_drv->name);
268 
269 	if ((!p_drv->probe) || (!p_dev->function_config) ||
270 	    (!try_module_get(p_drv->owner))) {
271 		ret = -EINVAL;
272 		goto put_dev;
273 	}
274 
275 	/* set up some more device information */
276 	ret = pccard_read_tuple(p_dev->socket, p_dev->func, CISTPL_CONFIG,
277 				&cis_config);
278 	if (!ret) {
279 		p_dev->config_base = cis_config.base;
280 		p_dev->config_regs = cis_config.rmask[0];
281 		dev_dbg(dev, "base %x, regs %x", p_dev->config_base,
282 			p_dev->config_regs);
283 	} else {
284 		dev_info(dev,
285 			 "pcmcia: could not parse base and rmask0 of CIS\n");
286 		p_dev->config_base = 0;
287 		p_dev->config_regs = 0;
288 	}
289 
290 	ret = p_drv->probe(p_dev);
291 	if (ret) {
292 		dev_dbg(dev, "binding to %s failed with %d\n",
293 			   p_drv->name, ret);
294 		goto put_module;
295 	}
296 	dev_dbg(dev, "%s bound: Vpp %d.%d, idx %x, IRQ %d", p_drv->name,
297 		p_dev->vpp/10, p_dev->vpp%10, p_dev->config_index, p_dev->irq);
298 	dev_dbg(dev, "resources: ioport %pR %pR iomem %pR %pR %pR",
299 		p_dev->resource[0], p_dev->resource[1], p_dev->resource[2],
300 		p_dev->resource[3], p_dev->resource[4]);
301 
302 	mutex_lock(&s->ops_mutex);
303 	if ((s->pcmcia_pfc) &&
304 	    (p_dev->socket->device_count == 1) && (p_dev->device_no == 0))
305 		pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
306 	mutex_unlock(&s->ops_mutex);
307 
308 put_module:
309 	if (ret)
310 		module_put(p_drv->owner);
311 put_dev:
312 	if (ret)
313 		put_device(dev);
314 	return ret;
315 }
316 
317 
318 /*
319  * Removes a PCMCIA card from the device tree and socket list.
320  */
321 static void pcmcia_card_remove(struct pcmcia_socket *s, struct pcmcia_device *leftover)
322 {
323 	struct pcmcia_device	*p_dev;
324 	struct pcmcia_device	*tmp;
325 
326 	dev_dbg(leftover ? &leftover->dev : &s->dev,
327 		   "pcmcia_card_remove(%d) %s\n", s->sock,
328 		   leftover ? leftover->devname : "");
329 
330 	mutex_lock(&s->ops_mutex);
331 	if (!leftover)
332 		s->device_count = 0;
333 	else
334 		s->device_count = 1;
335 	mutex_unlock(&s->ops_mutex);
336 
337 	/* unregister all pcmcia_devices registered with this socket, except leftover */
338 	list_for_each_entry_safe(p_dev, tmp, &s->devices_list, socket_device_list) {
339 		if (p_dev == leftover)
340 			continue;
341 
342 		mutex_lock(&s->ops_mutex);
343 		list_del(&p_dev->socket_device_list);
344 		mutex_unlock(&s->ops_mutex);
345 
346 		dev_dbg(&p_dev->dev, "unregistering device\n");
347 		device_unregister(&p_dev->dev);
348 	}
349 
350 	return;
351 }
352 
353 static int pcmcia_device_remove(struct device *dev)
354 {
355 	struct pcmcia_device *p_dev;
356 	struct pcmcia_driver *p_drv;
357 	int i;
358 
359 	p_dev = to_pcmcia_dev(dev);
360 	p_drv = to_pcmcia_drv(dev->driver);
361 
362 	dev_dbg(dev, "removing device\n");
363 
364 	/* If we're removing the primary module driving a
365 	 * pseudo multi-function card, we need to unbind
366 	 * all devices
367 	 */
368 	if ((p_dev->socket->pcmcia_pfc) &&
369 	    (p_dev->socket->device_count > 0) &&
370 	    (p_dev->device_no == 0))
371 		pcmcia_card_remove(p_dev->socket, p_dev);
372 
373 	/* detach the "instance" */
374 	if (!p_drv)
375 		return 0;
376 
377 	if (p_drv->remove)
378 		p_drv->remove(p_dev);
379 
380 	/* check for proper unloading */
381 	if (p_dev->_irq || p_dev->_io || p_dev->_locked)
382 		dev_info(dev,
383 			 "pcmcia: driver %s did not release config properly\n",
384 			 p_drv->name);
385 
386 	for (i = 0; i < MAX_WIN; i++)
387 		if (p_dev->_win & CLIENT_WIN_REQ(i))
388 			dev_info(dev,
389 				 "pcmcia: driver %s did not release window properly\n",
390 				 p_drv->name);
391 
392 	/* references from pcmcia_probe_device */
393 	pcmcia_put_dev(p_dev);
394 	module_put(p_drv->owner);
395 
396 	return 0;
397 }
398 
399 
400 /*
401  * pcmcia_device_query -- determine information about a pcmcia device
402  */
403 static int pcmcia_device_query(struct pcmcia_device *p_dev)
404 {
405 	cistpl_manfid_t manf_id;
406 	cistpl_funcid_t func_id;
407 	cistpl_vers_1_t	*vers1;
408 	unsigned int i;
409 
410 	vers1 = kmalloc(sizeof(*vers1), GFP_KERNEL);
411 	if (!vers1)
412 		return -ENOMEM;
413 
414 	if (!pccard_read_tuple(p_dev->socket, BIND_FN_ALL,
415 			       CISTPL_MANFID, &manf_id)) {
416 		mutex_lock(&p_dev->socket->ops_mutex);
417 		p_dev->manf_id = manf_id.manf;
418 		p_dev->card_id = manf_id.card;
419 		p_dev->has_manf_id = 1;
420 		p_dev->has_card_id = 1;
421 		mutex_unlock(&p_dev->socket->ops_mutex);
422 	}
423 
424 	if (!pccard_read_tuple(p_dev->socket, p_dev->func,
425 			       CISTPL_FUNCID, &func_id)) {
426 		mutex_lock(&p_dev->socket->ops_mutex);
427 		p_dev->func_id = func_id.func;
428 		p_dev->has_func_id = 1;
429 		mutex_unlock(&p_dev->socket->ops_mutex);
430 	} else {
431 		/* rule of thumb: cards with no FUNCID, but with
432 		 * common memory device geometry information, are
433 		 * probably memory cards (from pcmcia-cs) */
434 		cistpl_device_geo_t *devgeo;
435 
436 		devgeo = kmalloc(sizeof(*devgeo), GFP_KERNEL);
437 		if (!devgeo) {
438 			kfree(vers1);
439 			return -ENOMEM;
440 		}
441 		if (!pccard_read_tuple(p_dev->socket, p_dev->func,
442 				      CISTPL_DEVICE_GEO, devgeo)) {
443 			dev_dbg(&p_dev->dev,
444 				   "mem device geometry probably means "
445 				   "FUNCID_MEMORY\n");
446 			mutex_lock(&p_dev->socket->ops_mutex);
447 			p_dev->func_id = CISTPL_FUNCID_MEMORY;
448 			p_dev->has_func_id = 1;
449 			mutex_unlock(&p_dev->socket->ops_mutex);
450 		}
451 		kfree(devgeo);
452 	}
453 
454 	if (!pccard_read_tuple(p_dev->socket, BIND_FN_ALL, CISTPL_VERS_1,
455 			       vers1)) {
456 		mutex_lock(&p_dev->socket->ops_mutex);
457 		for (i = 0; i < min_t(unsigned int, 4, vers1->ns); i++) {
458 			char *tmp;
459 			unsigned int length;
460 			char *new;
461 
462 			tmp = vers1->str + vers1->ofs[i];
463 
464 			length = strlen(tmp) + 1;
465 			if ((length < 2) || (length > 255))
466 				continue;
467 
468 			new = kstrdup(tmp, GFP_KERNEL);
469 			if (!new)
470 				continue;
471 
472 			tmp = p_dev->prod_id[i];
473 			p_dev->prod_id[i] = new;
474 			kfree(tmp);
475 		}
476 		mutex_unlock(&p_dev->socket->ops_mutex);
477 	}
478 
479 	kfree(vers1);
480 	return 0;
481 }
482 
483 
484 static struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s,
485 					       unsigned int function)
486 {
487 	struct pcmcia_device *p_dev, *tmp_dev;
488 	int i;
489 
490 	s = pcmcia_get_socket(s);
491 	if (!s)
492 		return NULL;
493 
494 	pr_debug("adding device to %d, function %d\n", s->sock, function);
495 
496 	p_dev = kzalloc(sizeof(struct pcmcia_device), GFP_KERNEL);
497 	if (!p_dev)
498 		goto err_put;
499 
500 	mutex_lock(&s->ops_mutex);
501 	p_dev->device_no = (s->device_count++);
502 	mutex_unlock(&s->ops_mutex);
503 
504 	/* max of 2 PFC devices */
505 	if ((p_dev->device_no >= 2) && (function == 0))
506 		goto err_free;
507 
508 	/* max of 4 devices overall */
509 	if (p_dev->device_no >= 4)
510 		goto err_free;
511 
512 	p_dev->socket = s;
513 	p_dev->func   = function;
514 
515 	p_dev->dev.bus = &pcmcia_bus_type;
516 	p_dev->dev.parent = s->dev.parent;
517 	p_dev->dev.release = pcmcia_release_dev;
518 	/* by default don't allow DMA */
519 	p_dev->dma_mask = DMA_MASK_NONE;
520 	p_dev->dev.dma_mask = &p_dev->dma_mask;
521 	dev_set_name(&p_dev->dev, "%d.%d", p_dev->socket->sock, p_dev->device_no);
522 	if (!dev_name(&p_dev->dev))
523 		goto err_free;
524 	p_dev->devname = kasprintf(GFP_KERNEL, "pcmcia%s", dev_name(&p_dev->dev));
525 	if (!p_dev->devname)
526 		goto err_free;
527 	dev_dbg(&p_dev->dev, "devname is %s\n", p_dev->devname);
528 
529 	mutex_lock(&s->ops_mutex);
530 
531 	/*
532 	 * p_dev->function_config must be the same for all card functions.
533 	 * Note that this is serialized by ops_mutex, so that only one
534 	 * such struct will be created.
535 	 */
536 	list_for_each_entry(tmp_dev, &s->devices_list, socket_device_list)
537 		if (p_dev->func == tmp_dev->func) {
538 			p_dev->function_config = tmp_dev->function_config;
539 			p_dev->irq = tmp_dev->irq;
540 			kref_get(&p_dev->function_config->ref);
541 		}
542 
543 	/* Add to the list in pcmcia_bus_socket */
544 	list_add(&p_dev->socket_device_list, &s->devices_list);
545 
546 	if (pcmcia_setup_irq(p_dev))
547 		dev_warn(&p_dev->dev,
548 			"IRQ setup failed -- device might not work\n");
549 
550 	if (!p_dev->function_config) {
551 		config_t *c;
552 		dev_dbg(&p_dev->dev, "creating config_t\n");
553 		c = kzalloc(sizeof(struct config_t), GFP_KERNEL);
554 		if (!c) {
555 			mutex_unlock(&s->ops_mutex);
556 			goto err_unreg;
557 		}
558 		p_dev->function_config = c;
559 		kref_init(&c->ref);
560 		for (i = 0; i < MAX_IO_WIN; i++) {
561 			c->io[i].name = p_dev->devname;
562 			c->io[i].flags = IORESOURCE_IO;
563 		}
564 		for (i = 0; i < MAX_WIN; i++) {
565 			c->mem[i].name = p_dev->devname;
566 			c->mem[i].flags = IORESOURCE_MEM;
567 		}
568 	}
569 	for (i = 0; i < MAX_IO_WIN; i++)
570 		p_dev->resource[i] = &p_dev->function_config->io[i];
571 	for (; i < (MAX_IO_WIN + MAX_WIN); i++)
572 		p_dev->resource[i] = &p_dev->function_config->mem[i-MAX_IO_WIN];
573 
574 	mutex_unlock(&s->ops_mutex);
575 
576 	dev_notice(&p_dev->dev, "pcmcia: registering new device %s (IRQ: %d)\n",
577 		   p_dev->devname, p_dev->irq);
578 
579 	pcmcia_device_query(p_dev);
580 
581 	if (device_register(&p_dev->dev))
582 		goto err_unreg;
583 
584 	return p_dev;
585 
586  err_unreg:
587 	mutex_lock(&s->ops_mutex);
588 	list_del(&p_dev->socket_device_list);
589 	mutex_unlock(&s->ops_mutex);
590 
591  err_free:
592 	mutex_lock(&s->ops_mutex);
593 	s->device_count--;
594 	mutex_unlock(&s->ops_mutex);
595 
596 	for (i = 0; i < 4; i++)
597 		kfree(p_dev->prod_id[i]);
598 	kfree(p_dev->devname);
599 	kfree(p_dev);
600  err_put:
601 	pcmcia_put_socket(s);
602 
603 	return NULL;
604 }
605 
606 
607 static int pcmcia_card_add(struct pcmcia_socket *s)
608 {
609 	cistpl_longlink_mfc_t mfc;
610 	unsigned int no_funcs, i, no_chains;
611 	int ret = -EAGAIN;
612 
613 	mutex_lock(&s->ops_mutex);
614 	if (!(s->resource_setup_done)) {
615 		dev_dbg(&s->dev,
616 			   "no resources available, delaying card_add\n");
617 		mutex_unlock(&s->ops_mutex);
618 		return -EAGAIN; /* try again, but later... */
619 	}
620 
621 	if (pcmcia_validate_mem(s)) {
622 		dev_dbg(&s->dev, "validating mem resources failed, "
623 		       "delaying card_add\n");
624 		mutex_unlock(&s->ops_mutex);
625 		return -EAGAIN; /* try again, but later... */
626 	}
627 	mutex_unlock(&s->ops_mutex);
628 
629 	ret = pccard_validate_cis(s, &no_chains);
630 	if (ret || !no_chains) {
631 #if defined(CONFIG_MTD_PCMCIA_ANONYMOUS)
632 		/* Set up as an anonymous card. If we don't have anonymous
633 		   memory support then just error the card as there is no
634 		   point trying to second guess.
635 
636 		   Note: some cards have just a device entry, it may be
637 		   worth extending support to cover these in future */
638 		if (ret == -EIO) {
639 			dev_info(&s->dev, "no CIS, assuming an anonymous memory card.\n");
640 			pcmcia_replace_cis(s, "\xFF", 1);
641 			no_chains = 1;
642 			ret = 0;
643 		} else
644 #endif
645 		{
646 			dev_dbg(&s->dev, "invalid CIS or invalid resources\n");
647 			return -ENODEV;
648 		}
649 	}
650 
651 	if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC, &mfc))
652 		no_funcs = mfc.nfn;
653 	else
654 		no_funcs = 1;
655 	s->functions = no_funcs;
656 
657 	for (i = 0; i < no_funcs; i++)
658 		pcmcia_device_add(s, i);
659 
660 	return ret;
661 }
662 
663 
664 static int pcmcia_requery_callback(struct device *dev, void *_data)
665 {
666 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
667 	if (!p_dev->dev.driver) {
668 		dev_dbg(dev, "update device information\n");
669 		pcmcia_device_query(p_dev);
670 	}
671 
672 	return 0;
673 }
674 
675 
676 static void pcmcia_requery(struct pcmcia_socket *s)
677 {
678 	int has_pfc;
679 
680 	if (!(s->state & SOCKET_PRESENT))
681 		return;
682 
683 	if (s->functions == 0) {
684 		pcmcia_card_add(s);
685 		return;
686 	}
687 
688 	/* some device information might have changed because of a CIS
689 	 * update or because we can finally read it correctly... so
690 	 * determine it again, overwriting old values if necessary. */
691 	bus_for_each_dev(&pcmcia_bus_type, NULL, NULL, pcmcia_requery_callback);
692 
693 	/* if the CIS changed, we need to check whether the number of
694 	 * functions changed. */
695 	if (s->fake_cis) {
696 		int old_funcs, new_funcs;
697 		cistpl_longlink_mfc_t mfc;
698 
699 		/* does this cis override add or remove functions? */
700 		old_funcs = s->functions;
701 
702 		if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC,
703 					&mfc))
704 			new_funcs = mfc.nfn;
705 		else
706 			new_funcs = 1;
707 		if (old_funcs != new_funcs) {
708 			/* we need to re-start */
709 			pcmcia_card_remove(s, NULL);
710 			s->functions = 0;
711 			pcmcia_card_add(s);
712 		}
713 	}
714 
715 	/* If the PCMCIA device consists of two pseudo devices,
716 	 * call pcmcia_device_add() -- which will fail if both
717 	 * devices are already registered. */
718 	mutex_lock(&s->ops_mutex);
719 	has_pfc = s->pcmcia_pfc;
720 	mutex_unlock(&s->ops_mutex);
721 	if (has_pfc)
722 		pcmcia_device_add(s, 0);
723 
724 	/* we re-scan all devices, not just the ones connected to this
725 	 * socket. This does not matter, though. */
726 	if (bus_rescan_devices(&pcmcia_bus_type))
727 		dev_warn(&s->dev, "rescanning the bus failed\n");
728 }
729 
730 
731 #ifdef CONFIG_PCMCIA_LOAD_CIS
732 
733 /**
734  * pcmcia_load_firmware - load CIS from userspace if device-provided is broken
735  * @dev: the pcmcia device which needs a CIS override
736  * @filename: requested filename in /lib/firmware/
737  *
738  * This uses the in-kernel firmware loading mechanism to use a "fake CIS" if
739  * the one provided by the card is broken. The firmware files reside in
740  * /lib/firmware/ in userspace.
741  */
742 static int pcmcia_load_firmware(struct pcmcia_device *dev, char *filename)
743 {
744 	struct pcmcia_socket *s = dev->socket;
745 	const struct firmware *fw;
746 	int ret = -ENOMEM;
747 	cistpl_longlink_mfc_t mfc;
748 	int old_funcs, new_funcs = 1;
749 
750 	if (!filename)
751 		return -EINVAL;
752 
753 	dev_dbg(&dev->dev, "trying to load CIS file %s\n", filename);
754 
755 	if (request_firmware(&fw, filename, &dev->dev) == 0) {
756 		if (fw->size >= CISTPL_MAX_CIS_SIZE) {
757 			ret = -EINVAL;
758 			dev_err(&dev->dev, "pcmcia: CIS override is too big\n");
759 			goto release;
760 		}
761 
762 		if (!pcmcia_replace_cis(s, fw->data, fw->size))
763 			ret = 0;
764 		else {
765 			dev_err(&dev->dev, "pcmcia: CIS override failed\n");
766 			goto release;
767 		}
768 
769 		/* we need to re-start if the number of functions changed */
770 		old_funcs = s->functions;
771 		if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC,
772 					&mfc))
773 			new_funcs = mfc.nfn;
774 
775 		if (old_funcs != new_funcs)
776 			ret = -EBUSY;
777 
778 		/* update information */
779 		pcmcia_device_query(dev);
780 
781 		/* requery (as number of functions might have changed) */
782 		pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
783 	}
784  release:
785 	release_firmware(fw);
786 
787 	return ret;
788 }
789 
790 #else /* !CONFIG_PCMCIA_LOAD_CIS */
791 
792 static inline int pcmcia_load_firmware(struct pcmcia_device *dev,
793 				       char *filename)
794 {
795 	return -ENODEV;
796 }
797 
798 #endif
799 
800 
801 static inline int pcmcia_devmatch(struct pcmcia_device *dev,
802 				  const struct pcmcia_device_id *did)
803 {
804 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_MANF_ID) {
805 		if ((!dev->has_manf_id) || (dev->manf_id != did->manf_id))
806 			return 0;
807 	}
808 
809 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_CARD_ID) {
810 		if ((!dev->has_card_id) || (dev->card_id != did->card_id))
811 			return 0;
812 	}
813 
814 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_FUNCTION) {
815 		if (dev->func != did->function)
816 			return 0;
817 	}
818 
819 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID1) {
820 		if (!dev->prod_id[0])
821 			return 0;
822 		if (strcmp(did->prod_id[0], dev->prod_id[0]))
823 			return 0;
824 	}
825 
826 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID2) {
827 		if (!dev->prod_id[1])
828 			return 0;
829 		if (strcmp(did->prod_id[1], dev->prod_id[1]))
830 			return 0;
831 	}
832 
833 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID3) {
834 		if (!dev->prod_id[2])
835 			return 0;
836 		if (strcmp(did->prod_id[2], dev->prod_id[2]))
837 			return 0;
838 	}
839 
840 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_PROD_ID4) {
841 		if (!dev->prod_id[3])
842 			return 0;
843 		if (strcmp(did->prod_id[3], dev->prod_id[3]))
844 			return 0;
845 	}
846 
847 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) {
848 		dev_dbg(&dev->dev, "this is a pseudo-multi-function device\n");
849 		mutex_lock(&dev->socket->ops_mutex);
850 		dev->socket->pcmcia_pfc = 1;
851 		mutex_unlock(&dev->socket->ops_mutex);
852 		if (dev->device_no != did->device_no)
853 			return 0;
854 	}
855 
856 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_FUNC_ID) {
857 		int ret;
858 
859 		if ((!dev->has_func_id) || (dev->func_id != did->func_id))
860 			return 0;
861 
862 		/* if this is a pseudo-multi-function device,
863 		 * we need explicit matches */
864 		if (dev->socket->pcmcia_pfc)
865 			return 0;
866 		if (dev->device_no)
867 			return 0;
868 
869 		/* also, FUNC_ID matching needs to be activated by userspace
870 		 * after it has re-checked that there is no possible module
871 		 * with a prod_id/manf_id/card_id match.
872 		 */
873 		mutex_lock(&dev->socket->ops_mutex);
874 		ret = dev->allow_func_id_match;
875 		mutex_unlock(&dev->socket->ops_mutex);
876 
877 		if (!ret) {
878 			dev_dbg(&dev->dev,
879 				"skipping FUNC_ID match until userspace ACK\n");
880 			return 0;
881 		}
882 	}
883 
884 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_FAKE_CIS) {
885 		dev_dbg(&dev->dev, "device needs a fake CIS\n");
886 		if (!dev->socket->fake_cis)
887 			if (pcmcia_load_firmware(dev, did->cisfile))
888 				return 0;
889 	}
890 
891 	if (did->match_flags & PCMCIA_DEV_ID_MATCH_ANONYMOUS) {
892 		int i;
893 		for (i = 0; i < 4; i++)
894 			if (dev->prod_id[i])
895 				return 0;
896 		if (dev->has_manf_id || dev->has_card_id || dev->has_func_id)
897 			return 0;
898 	}
899 
900 	return 1;
901 }
902 
903 
904 static int pcmcia_bus_match(struct device *dev, struct device_driver *drv)
905 {
906 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
907 	struct pcmcia_driver *p_drv = to_pcmcia_drv(drv);
908 	const struct pcmcia_device_id *did = p_drv->id_table;
909 	struct pcmcia_dynid *dynid;
910 
911 	/* match dynamic devices first */
912 	mutex_lock(&p_drv->dynids.lock);
913 	list_for_each_entry(dynid, &p_drv->dynids.list, node) {
914 		dev_dbg(dev, "trying to match to %s\n", drv->name);
915 		if (pcmcia_devmatch(p_dev, &dynid->id)) {
916 			dev_dbg(dev, "matched to %s\n", drv->name);
917 			mutex_unlock(&p_drv->dynids.lock);
918 			return 1;
919 		}
920 	}
921 	mutex_unlock(&p_drv->dynids.lock);
922 
923 	while (did && did->match_flags) {
924 		dev_dbg(dev, "trying to match to %s\n", drv->name);
925 		if (pcmcia_devmatch(p_dev, did)) {
926 			dev_dbg(dev, "matched to %s\n", drv->name);
927 			return 1;
928 		}
929 		did++;
930 	}
931 
932 	return 0;
933 }
934 
935 static int pcmcia_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
936 {
937 	struct pcmcia_device *p_dev;
938 	int i;
939 	u32 hash[4] = { 0, 0, 0, 0};
940 
941 	if (!dev)
942 		return -ENODEV;
943 
944 	p_dev = to_pcmcia_dev(dev);
945 
946 	/* calculate hashes */
947 	for (i = 0; i < 4; i++) {
948 		if (!p_dev->prod_id[i])
949 			continue;
950 		hash[i] = crc32(0, p_dev->prod_id[i], strlen(p_dev->prod_id[i]));
951 	}
952 
953 	if (add_uevent_var(env, "SOCKET_NO=%u", p_dev->socket->sock))
954 		return -ENOMEM;
955 
956 	if (add_uevent_var(env, "DEVICE_NO=%02X", p_dev->device_no))
957 		return -ENOMEM;
958 
959 	if (add_uevent_var(env, "MODALIAS=pcmcia:m%04Xc%04Xf%02Xfn%02Xpfn%02X"
960 			   "pa%08Xpb%08Xpc%08Xpd%08X",
961 			   p_dev->has_manf_id ? p_dev->manf_id : 0,
962 			   p_dev->has_card_id ? p_dev->card_id : 0,
963 			   p_dev->has_func_id ? p_dev->func_id : 0,
964 			   p_dev->func,
965 			   p_dev->device_no,
966 			   hash[0],
967 			   hash[1],
968 			   hash[2],
969 			   hash[3]))
970 		return -ENOMEM;
971 
972 	return 0;
973 }
974 
975 /************************ runtime PM support ***************************/
976 
977 static int pcmcia_dev_suspend(struct device *dev);
978 static int pcmcia_dev_resume(struct device *dev);
979 
980 static int runtime_suspend(struct device *dev)
981 {
982 	int rc;
983 
984 	device_lock(dev);
985 	rc = pcmcia_dev_suspend(dev);
986 	device_unlock(dev);
987 	return rc;
988 }
989 
990 static int runtime_resume(struct device *dev)
991 {
992 	int rc;
993 
994 	device_lock(dev);
995 	rc = pcmcia_dev_resume(dev);
996 	device_unlock(dev);
997 	return rc;
998 }
999 
1000 /************************ per-device sysfs output ***************************/
1001 
1002 #define pcmcia_device_attr(field, test, format)				\
1003 static ssize_t field##_show (struct device *dev, struct device_attribute *attr, char *buf)		\
1004 {									\
1005 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);		\
1006 	return p_dev->test ? sprintf(buf, format, p_dev->field) : -ENODEV; \
1007 }									\
1008 static DEVICE_ATTR_RO(field);
1009 
1010 #define pcmcia_device_stringattr(name, field)					\
1011 static ssize_t name##_show (struct device *dev, struct device_attribute *attr, char *buf)		\
1012 {									\
1013 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);		\
1014 	return p_dev->field ? sprintf(buf, "%s\n", p_dev->field) : -ENODEV; \
1015 }									\
1016 static DEVICE_ATTR_RO(name);
1017 
1018 pcmcia_device_attr(func_id, has_func_id, "0x%02x\n");
1019 pcmcia_device_attr(manf_id, has_manf_id, "0x%04x\n");
1020 pcmcia_device_attr(card_id, has_card_id, "0x%04x\n");
1021 pcmcia_device_stringattr(prod_id1, prod_id[0]);
1022 pcmcia_device_stringattr(prod_id2, prod_id[1]);
1023 pcmcia_device_stringattr(prod_id3, prod_id[2]);
1024 pcmcia_device_stringattr(prod_id4, prod_id[3]);
1025 
1026 static ssize_t function_show(struct device *dev, struct device_attribute *attr,
1027 			     char *buf)
1028 {
1029 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1030 	return p_dev->socket ? sprintf(buf, "0x%02x\n", p_dev->func) : -ENODEV;
1031 }
1032 static DEVICE_ATTR_RO(function);
1033 
1034 static ssize_t resources_show(struct device *dev,
1035 			      struct device_attribute *attr, char *buf)
1036 {
1037 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1038 	char *str = buf;
1039 	int i;
1040 
1041 	for (i = 0; i < PCMCIA_NUM_RESOURCES; i++)
1042 		str += sprintf(str, "%pr\n", p_dev->resource[i]);
1043 
1044 	return str - buf;
1045 }
1046 static DEVICE_ATTR_RO(resources);
1047 
1048 static ssize_t pm_state_show(struct device *dev, struct device_attribute *attr, char *buf)
1049 {
1050 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1051 
1052 	if (p_dev->suspended)
1053 		return sprintf(buf, "off\n");
1054 	else
1055 		return sprintf(buf, "on\n");
1056 }
1057 
1058 static ssize_t pm_state_store(struct device *dev, struct device_attribute *attr,
1059 			      const char *buf, size_t count)
1060 {
1061 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1062 	int ret = 0;
1063 
1064 	if (!count)
1065 		return -EINVAL;
1066 
1067 	if ((!p_dev->suspended) && !strncmp(buf, "off", 3))
1068 		ret = runtime_suspend(dev);
1069 	else if (p_dev->suspended && !strncmp(buf, "on", 2))
1070 		ret = runtime_resume(dev);
1071 
1072 	return ret ? ret : count;
1073 }
1074 static DEVICE_ATTR_RW(pm_state);
1075 
1076 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
1077 {
1078 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1079 	int i;
1080 	u32 hash[4] = { 0, 0, 0, 0};
1081 
1082 	/* calculate hashes */
1083 	for (i = 0; i < 4; i++) {
1084 		if (!p_dev->prod_id[i])
1085 			continue;
1086 		hash[i] = crc32(0, p_dev->prod_id[i],
1087 				strlen(p_dev->prod_id[i]));
1088 	}
1089 	return sprintf(buf, "pcmcia:m%04Xc%04Xf%02Xfn%02Xpfn%02X"
1090 				"pa%08Xpb%08Xpc%08Xpd%08X\n",
1091 				p_dev->has_manf_id ? p_dev->manf_id : 0,
1092 				p_dev->has_card_id ? p_dev->card_id : 0,
1093 				p_dev->has_func_id ? p_dev->func_id : 0,
1094 				p_dev->func, p_dev->device_no,
1095 				hash[0], hash[1], hash[2], hash[3]);
1096 }
1097 static DEVICE_ATTR_RO(modalias);
1098 
1099 static ssize_t allow_func_id_match_store(struct device *dev,
1100 		struct device_attribute *attr, const char *buf, size_t count)
1101 {
1102 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1103 
1104 	if (!count)
1105 		return -EINVAL;
1106 
1107 	mutex_lock(&p_dev->socket->ops_mutex);
1108 	p_dev->allow_func_id_match = 1;
1109 	mutex_unlock(&p_dev->socket->ops_mutex);
1110 	pcmcia_parse_uevents(p_dev->socket, PCMCIA_UEVENT_REQUERY);
1111 
1112 	return count;
1113 }
1114 static DEVICE_ATTR_WO(allow_func_id_match);
1115 
1116 static struct attribute *pcmcia_dev_attrs[] = {
1117 	&dev_attr_resources.attr,
1118 	&dev_attr_pm_state.attr,
1119 	&dev_attr_function.attr,
1120 	&dev_attr_func_id.attr,
1121 	&dev_attr_manf_id.attr,
1122 	&dev_attr_card_id.attr,
1123 	&dev_attr_prod_id1.attr,
1124 	&dev_attr_prod_id2.attr,
1125 	&dev_attr_prod_id3.attr,
1126 	&dev_attr_prod_id4.attr,
1127 	&dev_attr_modalias.attr,
1128 	&dev_attr_allow_func_id_match.attr,
1129 	NULL,
1130 };
1131 ATTRIBUTE_GROUPS(pcmcia_dev);
1132 
1133 /* PM support, also needed for reset */
1134 
1135 static int pcmcia_dev_suspend(struct device *dev)
1136 {
1137 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1138 	struct pcmcia_driver *p_drv = NULL;
1139 	int ret = 0;
1140 
1141 	mutex_lock(&p_dev->socket->ops_mutex);
1142 	if (p_dev->suspended) {
1143 		mutex_unlock(&p_dev->socket->ops_mutex);
1144 		return 0;
1145 	}
1146 	p_dev->suspended = 1;
1147 	mutex_unlock(&p_dev->socket->ops_mutex);
1148 
1149 	dev_dbg(dev, "suspending\n");
1150 
1151 	if (dev->driver)
1152 		p_drv = to_pcmcia_drv(dev->driver);
1153 
1154 	if (!p_drv)
1155 		goto out;
1156 
1157 	if (p_drv->suspend) {
1158 		ret = p_drv->suspend(p_dev);
1159 		if (ret) {
1160 			dev_err(dev,
1161 				"pcmcia: device %s (driver %s) did not want to go to sleep (%d)\n",
1162 				p_dev->devname, p_drv->name, ret);
1163 			mutex_lock(&p_dev->socket->ops_mutex);
1164 			p_dev->suspended = 0;
1165 			mutex_unlock(&p_dev->socket->ops_mutex);
1166 			goto out;
1167 		}
1168 	}
1169 
1170 	if (p_dev->device_no == p_dev->func) {
1171 		dev_dbg(dev, "releasing configuration\n");
1172 		pcmcia_release_configuration(p_dev);
1173 	}
1174 
1175  out:
1176 	return ret;
1177 }
1178 
1179 
1180 static int pcmcia_dev_resume(struct device *dev)
1181 {
1182 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1183 	struct pcmcia_driver *p_drv = NULL;
1184 	int ret = 0;
1185 
1186 	mutex_lock(&p_dev->socket->ops_mutex);
1187 	if (!p_dev->suspended) {
1188 		mutex_unlock(&p_dev->socket->ops_mutex);
1189 		return 0;
1190 	}
1191 	p_dev->suspended = 0;
1192 	mutex_unlock(&p_dev->socket->ops_mutex);
1193 
1194 	dev_dbg(dev, "resuming\n");
1195 
1196 	if (dev->driver)
1197 		p_drv = to_pcmcia_drv(dev->driver);
1198 
1199 	if (!p_drv)
1200 		goto out;
1201 
1202 	if (p_dev->device_no == p_dev->func) {
1203 		dev_dbg(dev, "requesting configuration\n");
1204 		ret = pcmcia_enable_device(p_dev);
1205 		if (ret)
1206 			goto out;
1207 	}
1208 
1209 	if (p_drv->resume)
1210 		ret = p_drv->resume(p_dev);
1211 
1212  out:
1213 	return ret;
1214 }
1215 
1216 
1217 static int pcmcia_bus_suspend_callback(struct device *dev, void *_data)
1218 {
1219 	struct pcmcia_socket *skt = _data;
1220 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1221 
1222 	if (p_dev->socket != skt || p_dev->suspended)
1223 		return 0;
1224 
1225 	return runtime_suspend(dev);
1226 }
1227 
1228 static int pcmcia_bus_resume_callback(struct device *dev, void *_data)
1229 {
1230 	struct pcmcia_socket *skt = _data;
1231 	struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
1232 
1233 	if (p_dev->socket != skt || !p_dev->suspended)
1234 		return 0;
1235 
1236 	runtime_resume(dev);
1237 
1238 	return 0;
1239 }
1240 
1241 static int pcmcia_bus_resume(struct pcmcia_socket *skt)
1242 {
1243 	dev_dbg(&skt->dev, "resuming socket %d\n", skt->sock);
1244 	bus_for_each_dev(&pcmcia_bus_type, NULL, skt, pcmcia_bus_resume_callback);
1245 	return 0;
1246 }
1247 
1248 static int pcmcia_bus_suspend(struct pcmcia_socket *skt)
1249 {
1250 	dev_dbg(&skt->dev, "suspending socket %d\n", skt->sock);
1251 	if (bus_for_each_dev(&pcmcia_bus_type, NULL, skt,
1252 			     pcmcia_bus_suspend_callback)) {
1253 		pcmcia_bus_resume(skt);
1254 		return -EIO;
1255 	}
1256 	return 0;
1257 }
1258 
1259 static int pcmcia_bus_remove(struct pcmcia_socket *skt)
1260 {
1261 	atomic_set(&skt->present, 0);
1262 	pcmcia_card_remove(skt, NULL);
1263 
1264 	mutex_lock(&skt->ops_mutex);
1265 	destroy_cis_cache(skt);
1266 	pcmcia_cleanup_irq(skt);
1267 	mutex_unlock(&skt->ops_mutex);
1268 
1269 	return 0;
1270 }
1271 
1272 static int pcmcia_bus_add(struct pcmcia_socket *skt)
1273 {
1274 	atomic_set(&skt->present, 1);
1275 
1276 	mutex_lock(&skt->ops_mutex);
1277 	skt->pcmcia_pfc = 0;
1278 	destroy_cis_cache(skt); /* to be on the safe side... */
1279 	mutex_unlock(&skt->ops_mutex);
1280 
1281 	pcmcia_card_add(skt);
1282 
1283 	return 0;
1284 }
1285 
1286 static int pcmcia_bus_early_resume(struct pcmcia_socket *skt)
1287 {
1288 	if (!verify_cis_cache(skt))
1289 		return 0;
1290 
1291 	dev_dbg(&skt->dev, "cis mismatch - different card\n");
1292 
1293 	/* first, remove the card */
1294 	pcmcia_bus_remove(skt);
1295 
1296 	mutex_lock(&skt->ops_mutex);
1297 	destroy_cis_cache(skt);
1298 	kfree(skt->fake_cis);
1299 	skt->fake_cis = NULL;
1300 	skt->functions = 0;
1301 	mutex_unlock(&skt->ops_mutex);
1302 
1303 	/* now, add the new card */
1304 	pcmcia_bus_add(skt);
1305 	return 0;
1306 }
1307 
1308 
1309 /*
1310  * NOTE: This is racy. There's no guarantee the card will still be
1311  * physically present, even if the call to this function returns
1312  * non-NULL. Furthermore, the device driver most likely is unbound
1313  * almost immediately, so the timeframe where pcmcia_dev_present
1314  * returns NULL is probably really really small.
1315  */
1316 struct pcmcia_device *pcmcia_dev_present(struct pcmcia_device *_p_dev)
1317 {
1318 	struct pcmcia_device *p_dev;
1319 	struct pcmcia_device *ret = NULL;
1320 
1321 	p_dev = pcmcia_get_dev(_p_dev);
1322 	if (!p_dev)
1323 		return NULL;
1324 
1325 	if (atomic_read(&p_dev->socket->present) != 0)
1326 		ret = p_dev;
1327 
1328 	pcmcia_put_dev(p_dev);
1329 	return ret;
1330 }
1331 EXPORT_SYMBOL(pcmcia_dev_present);
1332 
1333 
1334 static struct pcmcia_callback pcmcia_bus_callback = {
1335 	.owner = THIS_MODULE,
1336 	.add = pcmcia_bus_add,
1337 	.remove = pcmcia_bus_remove,
1338 	.requery = pcmcia_requery,
1339 	.validate = pccard_validate_cis,
1340 	.suspend = pcmcia_bus_suspend,
1341 	.early_resume = pcmcia_bus_early_resume,
1342 	.resume = pcmcia_bus_resume,
1343 };
1344 
1345 static int pcmcia_bus_add_socket(struct device *dev,
1346 					   struct class_interface *class_intf)
1347 {
1348 	struct pcmcia_socket *socket = dev_get_drvdata(dev);
1349 	int ret;
1350 
1351 	socket = pcmcia_get_socket(socket);
1352 	if (!socket) {
1353 		dev_err(dev, "PCMCIA obtaining reference to socket failed\n");
1354 		return -ENODEV;
1355 	}
1356 
1357 	ret = sysfs_create_bin_file(&dev->kobj, &pccard_cis_attr);
1358 	if (ret) {
1359 		dev_err(dev, "PCMCIA registration failed\n");
1360 		pcmcia_put_socket(socket);
1361 		return ret;
1362 	}
1363 
1364 	INIT_LIST_HEAD(&socket->devices_list);
1365 	socket->pcmcia_pfc = 0;
1366 	socket->device_count = 0;
1367 	atomic_set(&socket->present, 0);
1368 
1369 	ret = pccard_register_pcmcia(socket, &pcmcia_bus_callback);
1370 	if (ret) {
1371 		dev_err(dev, "PCMCIA registration failed\n");
1372 		pcmcia_put_socket(socket);
1373 		return ret;
1374 	}
1375 
1376 	return 0;
1377 }
1378 
1379 static void pcmcia_bus_remove_socket(struct device *dev,
1380 				     struct class_interface *class_intf)
1381 {
1382 	struct pcmcia_socket *socket = dev_get_drvdata(dev);
1383 
1384 	if (!socket)
1385 		return;
1386 
1387 	pccard_register_pcmcia(socket, NULL);
1388 
1389 	/* unregister any unbound devices */
1390 	mutex_lock(&socket->skt_mutex);
1391 	pcmcia_card_remove(socket, NULL);
1392 	release_cis_mem(socket);
1393 	mutex_unlock(&socket->skt_mutex);
1394 
1395 	sysfs_remove_bin_file(&dev->kobj, &pccard_cis_attr);
1396 
1397 	pcmcia_put_socket(socket);
1398 
1399 	return;
1400 }
1401 
1402 
1403 /* the pcmcia_bus_interface is used to handle pcmcia socket devices */
1404 static struct class_interface pcmcia_bus_interface __refdata = {
1405 	.class = &pcmcia_socket_class,
1406 	.add_dev = &pcmcia_bus_add_socket,
1407 	.remove_dev = &pcmcia_bus_remove_socket,
1408 };
1409 
1410 static const struct dev_pm_ops pcmcia_bus_pm_ops = {
1411 	SET_SYSTEM_SLEEP_PM_OPS(pcmcia_dev_suspend, pcmcia_dev_resume)
1412 };
1413 
1414 struct bus_type pcmcia_bus_type = {
1415 	.name = "pcmcia",
1416 	.uevent = pcmcia_bus_uevent,
1417 	.match = pcmcia_bus_match,
1418 	.dev_groups = pcmcia_dev_groups,
1419 	.probe = pcmcia_device_probe,
1420 	.remove = pcmcia_device_remove,
1421 	.pm = &pcmcia_bus_pm_ops,
1422 };
1423 
1424 
1425 static int __init init_pcmcia_bus(void)
1426 {
1427 	int ret;
1428 
1429 	ret = bus_register(&pcmcia_bus_type);
1430 	if (ret < 0) {
1431 		printk(KERN_WARNING "pcmcia: bus_register error: %d\n", ret);
1432 		return ret;
1433 	}
1434 	ret = class_interface_register(&pcmcia_bus_interface);
1435 	if (ret < 0) {
1436 		printk(KERN_WARNING
1437 			"pcmcia: class_interface_register error: %d\n", ret);
1438 		bus_unregister(&pcmcia_bus_type);
1439 		return ret;
1440 	}
1441 
1442 	return 0;
1443 }
1444 fs_initcall(init_pcmcia_bus); /* one level after subsys_initcall so that
1445 			       * pcmcia_socket_class is already registered */
1446 
1447 
1448 static void __exit exit_pcmcia_bus(void)
1449 {
1450 	class_interface_unregister(&pcmcia_bus_interface);
1451 
1452 	bus_unregister(&pcmcia_bus_type);
1453 }
1454 module_exit(exit_pcmcia_bus);
1455 
1456 
1457 MODULE_ALIAS("ds");
1458