fb: adv7393: off by one in probe function
[deliverable/linux.git] / drivers / pci / hotplug / cpci_hotplug_core.c
1 /*
2 * CompactPCI Hot Plug Driver
3 *
4 * Copyright (C) 2002,2005 SOMA Networks, Inc.
5 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6 * Copyright (C) 2001 IBM Corp.
7 *
8 * All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or (at
13 * your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
18 * NON INFRINGEMENT. See the GNU General Public License for more
19 * details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 *
25 * Send feedback to <scottm@somanetworks.com>
26 */
27
28 #include <linux/module.h>
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/pci.h>
32 #include <linux/pci_hotplug.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/atomic.h>
36 #include <linux/delay.h>
37 #include <linux/kthread.h>
38 #include "cpci_hotplug.h"
39
40 #define DRIVER_AUTHOR "Scott Murray <scottm@somanetworks.com>"
41 #define DRIVER_DESC "CompactPCI Hot Plug Core"
42
43 #define MY_NAME "cpci_hotplug"
44
45 #define dbg(format, arg...) \
46 do { \
47 if (cpci_debug) \
48 printk(KERN_DEBUG "%s: " format "\n", \
49 MY_NAME, ## arg); \
50 } while (0)
51 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
52 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
53 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
54
55 /* local variables */
56 static DECLARE_RWSEM(list_rwsem);
57 static LIST_HEAD(slot_list);
58 static int slots;
59 static atomic_t extracting;
60 int cpci_debug;
61 static struct cpci_hp_controller *controller;
62 static struct task_struct *cpci_thread;
63 static int thread_finished;
64
65 static int enable_slot(struct hotplug_slot *slot);
66 static int disable_slot(struct hotplug_slot *slot);
67 static int set_attention_status(struct hotplug_slot *slot, u8 value);
68 static int get_power_status(struct hotplug_slot *slot, u8 *value);
69 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
70 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
71 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
72
73 static struct hotplug_slot_ops cpci_hotplug_slot_ops = {
74 .enable_slot = enable_slot,
75 .disable_slot = disable_slot,
76 .set_attention_status = set_attention_status,
77 .get_power_status = get_power_status,
78 .get_attention_status = get_attention_status,
79 .get_adapter_status = get_adapter_status,
80 .get_latch_status = get_latch_status,
81 };
82
83 static int
84 update_latch_status(struct hotplug_slot *hotplug_slot, u8 value)
85 {
86 struct hotplug_slot_info info;
87
88 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
89 info.latch_status = value;
90 return pci_hp_change_slot_info(hotplug_slot, &info);
91 }
92
93 static int
94 update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value)
95 {
96 struct hotplug_slot_info info;
97
98 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
99 info.adapter_status = value;
100 return pci_hp_change_slot_info(hotplug_slot, &info);
101 }
102
103 static int
104 enable_slot(struct hotplug_slot *hotplug_slot)
105 {
106 struct slot *slot = hotplug_slot->private;
107 int retval = 0;
108
109 dbg("%s - physical_slot = %s", __func__, slot_name(slot));
110
111 if (controller->ops->set_power)
112 retval = controller->ops->set_power(slot, 1);
113 return retval;
114 }
115
116 static int
117 disable_slot(struct hotplug_slot *hotplug_slot)
118 {
119 struct slot *slot = hotplug_slot->private;
120 int retval = 0;
121
122 dbg("%s - physical_slot = %s", __func__, slot_name(slot));
123
124 down_write(&list_rwsem);
125
126 /* Unconfigure device */
127 dbg("%s - unconfiguring slot %s", __func__, slot_name(slot));
128 retval = cpci_unconfigure_slot(slot);
129 if (retval) {
130 err("%s - could not unconfigure slot %s",
131 __func__, slot_name(slot));
132 goto disable_error;
133 }
134 dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot));
135
136 /* Clear EXT (by setting it) */
137 if (cpci_clear_ext(slot)) {
138 err("%s - could not clear EXT for slot %s",
139 __func__, slot_name(slot));
140 retval = -ENODEV;
141 goto disable_error;
142 }
143 cpci_led_on(slot);
144
145 if (controller->ops->set_power) {
146 retval = controller->ops->set_power(slot, 0);
147 if (retval)
148 goto disable_error;
149 }
150
151 if (update_adapter_status(slot->hotplug_slot, 0))
152 warn("failure to update adapter file");
153
154 if (slot->extracting) {
155 slot->extracting = 0;
156 atomic_dec(&extracting);
157 }
158 disable_error:
159 up_write(&list_rwsem);
160 return retval;
161 }
162
163 static u8
164 cpci_get_power_status(struct slot *slot)
165 {
166 u8 power = 1;
167
168 if (controller->ops->get_power)
169 power = controller->ops->get_power(slot);
170 return power;
171 }
172
173 static int
174 get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
175 {
176 struct slot *slot = hotplug_slot->private;
177
178 *value = cpci_get_power_status(slot);
179 return 0;
180 }
181
182 static int
183 get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
184 {
185 struct slot *slot = hotplug_slot->private;
186
187 *value = cpci_get_attention_status(slot);
188 return 0;
189 }
190
191 static int
192 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
193 {
194 return cpci_set_attention_status(hotplug_slot->private, status);
195 }
196
197 static int
198 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
199 {
200 *value = hotplug_slot->info->adapter_status;
201 return 0;
202 }
203
204 static int
205 get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
206 {
207 *value = hotplug_slot->info->latch_status;
208 return 0;
209 }
210
211 static void release_slot(struct hotplug_slot *hotplug_slot)
212 {
213 struct slot *slot = hotplug_slot->private;
214
215 kfree(slot->hotplug_slot->info);
216 kfree(slot->hotplug_slot);
217 pci_dev_put(slot->dev);
218 kfree(slot);
219 }
220
221 #define SLOT_NAME_SIZE 6
222
223 int
224 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
225 {
226 struct slot *slot;
227 struct hotplug_slot *hotplug_slot;
228 struct hotplug_slot_info *info;
229 char name[SLOT_NAME_SIZE];
230 int status;
231 int i;
232
233 if (!(controller && bus))
234 return -ENODEV;
235
236 /*
237 * Create a structure for each slot, and register that slot
238 * with the pci_hotplug subsystem.
239 */
240 for (i = first; i <= last; ++i) {
241 slot = kzalloc(sizeof(struct slot), GFP_KERNEL);
242 if (!slot) {
243 status = -ENOMEM;
244 goto error;
245 }
246
247 hotplug_slot =
248 kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
249 if (!hotplug_slot) {
250 status = -ENOMEM;
251 goto error_slot;
252 }
253 slot->hotplug_slot = hotplug_slot;
254
255 info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
256 if (!info) {
257 status = -ENOMEM;
258 goto error_hpslot;
259 }
260 hotplug_slot->info = info;
261
262 slot->bus = bus;
263 slot->number = i;
264 slot->devfn = PCI_DEVFN(i, 0);
265
266 snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i);
267
268 hotplug_slot->private = slot;
269 hotplug_slot->release = &release_slot;
270 hotplug_slot->ops = &cpci_hotplug_slot_ops;
271
272 /*
273 * Initialize the slot info structure with some known
274 * good values.
275 */
276 dbg("initializing slot %s", name);
277 info->power_status = cpci_get_power_status(slot);
278 info->attention_status = cpci_get_attention_status(slot);
279
280 dbg("registering slot %s", name);
281 status = pci_hp_register(slot->hotplug_slot, bus, i, name);
282 if (status) {
283 err("pci_hp_register failed with error %d", status);
284 goto error_info;
285 }
286 dbg("slot registered with name: %s", slot_name(slot));
287
288 /* Add slot to our internal list */
289 down_write(&list_rwsem);
290 list_add(&slot->slot_list, &slot_list);
291 slots++;
292 up_write(&list_rwsem);
293 }
294 return 0;
295 error_info:
296 kfree(info);
297 error_hpslot:
298 kfree(hotplug_slot);
299 error_slot:
300 kfree(slot);
301 error:
302 return status;
303 }
304 EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
305
306 int
307 cpci_hp_unregister_bus(struct pci_bus *bus)
308 {
309 struct slot *slot;
310 struct slot *tmp;
311 int status = 0;
312
313 down_write(&list_rwsem);
314 if (!slots) {
315 up_write(&list_rwsem);
316 return -1;
317 }
318 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
319 if (slot->bus == bus) {
320 list_del(&slot->slot_list);
321 slots--;
322
323 dbg("deregistering slot %s", slot_name(slot));
324 status = pci_hp_deregister(slot->hotplug_slot);
325 if (status) {
326 err("pci_hp_deregister failed with error %d",
327 status);
328 break;
329 }
330 }
331 }
332 up_write(&list_rwsem);
333 return status;
334 }
335 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
336
337 /* This is the interrupt mode interrupt handler */
338 static irqreturn_t
339 cpci_hp_intr(int irq, void *data)
340 {
341 dbg("entered cpci_hp_intr");
342
343 /* Check to see if it was our interrupt */
344 if ((controller->irq_flags & IRQF_SHARED) &&
345 !controller->ops->check_irq(controller->dev_id)) {
346 dbg("exited cpci_hp_intr, not our interrupt");
347 return IRQ_NONE;
348 }
349
350 /* Disable ENUM interrupt */
351 controller->ops->disable_irq();
352
353 /* Trigger processing by the event thread */
354 wake_up_process(cpci_thread);
355 return IRQ_HANDLED;
356 }
357
358 /*
359 * According to PICMG 2.1 R2.0, section 6.3.2, upon
360 * initialization, the system driver shall clear the
361 * INS bits of the cold-inserted devices.
362 */
363 static int
364 init_slots(int clear_ins)
365 {
366 struct slot *slot;
367 struct pci_dev *dev;
368
369 dbg("%s - enter", __func__);
370 down_read(&list_rwsem);
371 if (!slots) {
372 up_read(&list_rwsem);
373 return -1;
374 }
375 list_for_each_entry(slot, &slot_list, slot_list) {
376 dbg("%s - looking at slot %s", __func__, slot_name(slot));
377 if (clear_ins && cpci_check_and_clear_ins(slot))
378 dbg("%s - cleared INS for slot %s",
379 __func__, slot_name(slot));
380 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0));
381 if (dev) {
382 if (update_adapter_status(slot->hotplug_slot, 1))
383 warn("failure to update adapter file");
384 if (update_latch_status(slot->hotplug_slot, 1))
385 warn("failure to update latch file");
386 slot->dev = dev;
387 }
388 }
389 up_read(&list_rwsem);
390 dbg("%s - exit", __func__);
391 return 0;
392 }
393
394 static int
395 check_slots(void)
396 {
397 struct slot *slot;
398 int extracted;
399 int inserted;
400 u16 hs_csr;
401
402 down_read(&list_rwsem);
403 if (!slots) {
404 up_read(&list_rwsem);
405 err("no slots registered, shutting down");
406 return -1;
407 }
408 extracted = inserted = 0;
409 list_for_each_entry(slot, &slot_list, slot_list) {
410 dbg("%s - looking at slot %s", __func__, slot_name(slot));
411 if (cpci_check_and_clear_ins(slot)) {
412 /*
413 * Some broken hardware (e.g. PLX 9054AB) asserts
414 * ENUM# twice...
415 */
416 if (slot->dev) {
417 warn("slot %s already inserted",
418 slot_name(slot));
419 inserted++;
420 continue;
421 }
422
423 /* Process insertion */
424 dbg("%s - slot %s inserted", __func__, slot_name(slot));
425
426 /* GSM, debug */
427 hs_csr = cpci_get_hs_csr(slot);
428 dbg("%s - slot %s HS_CSR (1) = %04x",
429 __func__, slot_name(slot), hs_csr);
430
431 /* Configure device */
432 dbg("%s - configuring slot %s",
433 __func__, slot_name(slot));
434 if (cpci_configure_slot(slot)) {
435 err("%s - could not configure slot %s",
436 __func__, slot_name(slot));
437 continue;
438 }
439 dbg("%s - finished configuring slot %s",
440 __func__, slot_name(slot));
441
442 /* GSM, debug */
443 hs_csr = cpci_get_hs_csr(slot);
444 dbg("%s - slot %s HS_CSR (2) = %04x",
445 __func__, slot_name(slot), hs_csr);
446
447 if (update_latch_status(slot->hotplug_slot, 1))
448 warn("failure to update latch file");
449
450 if (update_adapter_status(slot->hotplug_slot, 1))
451 warn("failure to update adapter file");
452
453 cpci_led_off(slot);
454
455 /* GSM, debug */
456 hs_csr = cpci_get_hs_csr(slot);
457 dbg("%s - slot %s HS_CSR (3) = %04x",
458 __func__, slot_name(slot), hs_csr);
459
460 inserted++;
461 } else if (cpci_check_ext(slot)) {
462 /* Process extraction request */
463 dbg("%s - slot %s extracted",
464 __func__, slot_name(slot));
465
466 /* GSM, debug */
467 hs_csr = cpci_get_hs_csr(slot);
468 dbg("%s - slot %s HS_CSR = %04x",
469 __func__, slot_name(slot), hs_csr);
470
471 if (!slot->extracting) {
472 if (update_latch_status(slot->hotplug_slot, 0))
473 warn("failure to update latch file");
474
475 slot->extracting = 1;
476 atomic_inc(&extracting);
477 }
478 extracted++;
479 } else if (slot->extracting) {
480 hs_csr = cpci_get_hs_csr(slot);
481 if (hs_csr == 0xffff) {
482 /*
483 * Hmmm, we're likely hosed at this point, should we
484 * bother trying to tell the driver or not?
485 */
486 err("card in slot %s was improperly removed",
487 slot_name(slot));
488 if (update_adapter_status(slot->hotplug_slot, 0))
489 warn("failure to update adapter file");
490 slot->extracting = 0;
491 atomic_dec(&extracting);
492 }
493 }
494 }
495 up_read(&list_rwsem);
496 dbg("inserted=%d, extracted=%d, extracting=%d",
497 inserted, extracted, atomic_read(&extracting));
498 if (inserted || extracted)
499 return extracted;
500 else if (!atomic_read(&extracting)) {
501 err("cannot find ENUM# source, shutting down");
502 return -1;
503 }
504 return 0;
505 }
506
507 /* This is the interrupt mode worker thread body */
508 static int
509 event_thread(void *data)
510 {
511 int rc;
512
513 dbg("%s - event thread started", __func__);
514 while (1) {
515 dbg("event thread sleeping");
516 set_current_state(TASK_INTERRUPTIBLE);
517 schedule();
518 if (kthread_should_stop())
519 break;
520 do {
521 rc = check_slots();
522 if (rc > 0) {
523 /* Give userspace a chance to handle extraction */
524 msleep(500);
525 } else if (rc < 0) {
526 dbg("%s - error checking slots", __func__);
527 thread_finished = 1;
528 goto out;
529 }
530 } while (atomic_read(&extracting) && !kthread_should_stop());
531 if (kthread_should_stop())
532 break;
533
534 /* Re-enable ENUM# interrupt */
535 dbg("%s - re-enabling irq", __func__);
536 controller->ops->enable_irq();
537 }
538 out:
539 return 0;
540 }
541
542 /* This is the polling mode worker thread body */
543 static int
544 poll_thread(void *data)
545 {
546 int rc;
547
548 while (1) {
549 if (kthread_should_stop() || signal_pending(current))
550 break;
551 if (controller->ops->query_enum()) {
552 do {
553 rc = check_slots();
554 if (rc > 0) {
555 /* Give userspace a chance to handle extraction */
556 msleep(500);
557 } else if (rc < 0) {
558 dbg("%s - error checking slots", __func__);
559 thread_finished = 1;
560 goto out;
561 }
562 } while (atomic_read(&extracting) && !kthread_should_stop());
563 }
564 msleep(100);
565 }
566 out:
567 return 0;
568 }
569
570 static int
571 cpci_start_thread(void)
572 {
573 if (controller->irq)
574 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd");
575 else
576 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld");
577 if (IS_ERR(cpci_thread)) {
578 err("Can't start up our thread");
579 return PTR_ERR(cpci_thread);
580 }
581 thread_finished = 0;
582 return 0;
583 }
584
585 static void
586 cpci_stop_thread(void)
587 {
588 kthread_stop(cpci_thread);
589 thread_finished = 1;
590 }
591
592 int
593 cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
594 {
595 int status = 0;
596
597 if (controller)
598 return -1;
599 if (!(new_controller && new_controller->ops))
600 return -EINVAL;
601 if (new_controller->irq) {
602 if (!(new_controller->ops->enable_irq &&
603 new_controller->ops->disable_irq))
604 status = -EINVAL;
605 if (request_irq(new_controller->irq,
606 cpci_hp_intr,
607 new_controller->irq_flags,
608 MY_NAME,
609 new_controller->dev_id)) {
610 err("Can't get irq %d for the hotplug cPCI controller",
611 new_controller->irq);
612 status = -ENODEV;
613 }
614 dbg("%s - acquired controller irq %d",
615 __func__, new_controller->irq);
616 }
617 if (!status)
618 controller = new_controller;
619 return status;
620 }
621 EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
622
623 static void
624 cleanup_slots(void)
625 {
626 struct slot *slot;
627 struct slot *tmp;
628
629 /*
630 * Unregister all of our slots with the pci_hotplug subsystem,
631 * and free up all memory that we had allocated.
632 */
633 down_write(&list_rwsem);
634 if (!slots)
635 goto cleanup_null;
636 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
637 list_del(&slot->slot_list);
638 pci_hp_deregister(slot->hotplug_slot);
639 }
640 cleanup_null:
641 up_write(&list_rwsem);
642 return;
643 }
644
645 int
646 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
647 {
648 int status = 0;
649
650 if (controller) {
651 if (!thread_finished)
652 cpci_stop_thread();
653 if (controller->irq)
654 free_irq(controller->irq, controller->dev_id);
655 controller = NULL;
656 cleanup_slots();
657 } else
658 status = -ENODEV;
659 return status;
660 }
661 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
662
663 int
664 cpci_hp_start(void)
665 {
666 static int first = 1;
667 int status;
668
669 dbg("%s - enter", __func__);
670 if (!controller)
671 return -ENODEV;
672
673 down_read(&list_rwsem);
674 if (list_empty(&slot_list)) {
675 up_read(&list_rwsem);
676 return -ENODEV;
677 }
678 up_read(&list_rwsem);
679
680 status = init_slots(first);
681 if (first)
682 first = 0;
683 if (status)
684 return status;
685
686 status = cpci_start_thread();
687 if (status)
688 return status;
689 dbg("%s - thread started", __func__);
690
691 if (controller->irq) {
692 /* Start enum interrupt processing */
693 dbg("%s - enabling irq", __func__);
694 controller->ops->enable_irq();
695 }
696 dbg("%s - exit", __func__);
697 return 0;
698 }
699 EXPORT_SYMBOL_GPL(cpci_hp_start);
700
701 int
702 cpci_hp_stop(void)
703 {
704 if (!controller)
705 return -ENODEV;
706 if (controller->irq) {
707 /* Stop enum interrupt processing */
708 dbg("%s - disabling irq", __func__);
709 controller->ops->disable_irq();
710 }
711 cpci_stop_thread();
712 return 0;
713 }
714 EXPORT_SYMBOL_GPL(cpci_hp_stop);
715
716 int __init
717 cpci_hotplug_init(int debug)
718 {
719 cpci_debug = debug;
720 return 0;
721 }
722
723 void __exit
724 cpci_hotplug_exit(void)
725 {
726 /*
727 * Clean everything up.
728 */
729 cpci_hp_stop();
730 cpci_hp_unregister_controller(controller);
731 }
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