Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck...
[cascardo/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         if ((retval = cpci_unconfigure_slot(slot))) {
129                 err("%s - could not unconfigure slot %s",
130                     __func__, slot_name(slot));
131                 goto disable_error;
132         }
133         dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot));
134
135         /* Clear EXT (by setting it) */
136         if (cpci_clear_ext(slot)) {
137                 err("%s - could not clear EXT for slot %s",
138                     __func__, slot_name(slot));
139                 retval = -ENODEV;
140                 goto disable_error;
141         }
142         cpci_led_on(slot);
143
144         if (controller->ops->set_power)
145                 if ((retval = controller->ops->set_power(slot, 0)))
146                         goto disable_error;
147
148         if (update_adapter_status(slot->hotplug_slot, 0))
149                 warn("failure to update adapter file");
150
151         if (slot->extracting) {
152                 slot->extracting = 0;
153                 atomic_dec(&extracting);
154         }
155 disable_error:
156         up_write(&list_rwsem);
157         return retval;
158 }
159
160 static u8
161 cpci_get_power_status(struct slot *slot)
162 {
163         u8 power = 1;
164
165         if (controller->ops->get_power)
166                 power = controller->ops->get_power(slot);
167         return power;
168 }
169
170 static int
171 get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
172 {
173         struct slot *slot = hotplug_slot->private;
174
175         *value = cpci_get_power_status(slot);
176         return 0;
177 }
178
179 static int
180 get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
181 {
182         struct slot *slot = hotplug_slot->private;
183
184         *value = cpci_get_attention_status(slot);
185         return 0;
186 }
187
188 static int
189 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
190 {
191         return cpci_set_attention_status(hotplug_slot->private, status);
192 }
193
194 static int
195 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
196 {
197         *value = hotplug_slot->info->adapter_status;
198         return 0;
199 }
200
201 static int
202 get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
203 {
204         *value = hotplug_slot->info->latch_status;
205         return 0;
206 }
207
208 static void release_slot(struct hotplug_slot *hotplug_slot)
209 {
210         struct slot *slot = hotplug_slot->private;
211
212         kfree(slot->hotplug_slot->info);
213         kfree(slot->hotplug_slot);
214         if (slot->dev)
215                 pci_dev_put(slot->dev);
216         kfree(slot);
217 }
218
219 #define SLOT_NAME_SIZE  6
220
221 int
222 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
223 {
224         struct slot *slot;
225         struct hotplug_slot *hotplug_slot;
226         struct hotplug_slot_info *info;
227         char name[SLOT_NAME_SIZE];
228         int status;
229         int i;
230
231         if (!(controller && bus))
232                 return -ENODEV;
233
234         /*
235          * Create a structure for each slot, and register that slot
236          * with the pci_hotplug subsystem.
237          */
238         for (i = first; i <= last; ++i) {
239                 slot = kzalloc(sizeof (struct slot), GFP_KERNEL);
240                 if (!slot) {
241                         status = -ENOMEM;
242                         goto error;
243                 }
244
245                 hotplug_slot =
246                         kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL);
247                 if (!hotplug_slot) {
248                         status = -ENOMEM;
249                         goto error_slot;
250                 }
251                 slot->hotplug_slot = hotplug_slot;
252
253                 info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL);
254                 if (!info) {
255                         status = -ENOMEM;
256                         goto error_hpslot;
257                 }
258                 hotplug_slot->info = info;
259
260                 slot->bus = bus;
261                 slot->number = i;
262                 slot->devfn = PCI_DEVFN(i, 0);
263
264                 snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i);
265
266                 hotplug_slot->private = slot;
267                 hotplug_slot->release = &release_slot;
268                 hotplug_slot->ops = &cpci_hotplug_slot_ops;
269
270                 /*
271                  * Initialize the slot info structure with some known
272                  * good values.
273                  */
274                 dbg("initializing slot %s", name);
275                 info->power_status = cpci_get_power_status(slot);
276                 info->attention_status = cpci_get_attention_status(slot);
277
278                 dbg("registering slot %s", name);
279                 status = pci_hp_register(slot->hotplug_slot, bus, i, name);
280                 if (status) {
281                         err("pci_hp_register failed with error %d", status);
282                         goto error_info;
283                 }
284                 dbg("slot registered with name: %s", slot_name(slot));
285
286                 /* Add slot to our internal list */
287                 down_write(&list_rwsem);
288                 list_add(&slot->slot_list, &slot_list);
289                 slots++;
290                 up_write(&list_rwsem);
291         }
292         return 0;
293 error_info:
294         kfree(info);
295 error_hpslot:
296         kfree(hotplug_slot);
297 error_slot:
298         kfree(slot);
299 error:
300         return status;
301 }
302 EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
303
304 int
305 cpci_hp_unregister_bus(struct pci_bus *bus)
306 {
307         struct slot *slot;
308         struct slot *tmp;
309         int status = 0;
310
311         down_write(&list_rwsem);
312         if (!slots) {
313                 up_write(&list_rwsem);
314                 return -1;
315         }
316         list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
317                 if (slot->bus == bus) {
318                         list_del(&slot->slot_list);
319                         slots--;
320
321                         dbg("deregistering slot %s", slot_name(slot));
322                         status = pci_hp_deregister(slot->hotplug_slot);
323                         if (status) {
324                                 err("pci_hp_deregister failed with error %d",
325                                     status);
326                                 break;
327                         }
328                 }
329         }
330         up_write(&list_rwsem);
331         return status;
332 }
333 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
334
335 /* This is the interrupt mode interrupt handler */
336 static irqreturn_t
337 cpci_hp_intr(int irq, void *data)
338 {
339         dbg("entered cpci_hp_intr");
340
341         /* Check to see if it was our interrupt */
342         if ((controller->irq_flags & IRQF_SHARED) &&
343             !controller->ops->check_irq(controller->dev_id)) {
344                 dbg("exited cpci_hp_intr, not our interrupt");
345                 return IRQ_NONE;
346         }
347
348         /* Disable ENUM interrupt */
349         controller->ops->disable_irq();
350
351         /* Trigger processing by the event thread */
352         wake_up_process(cpci_thread);
353         return IRQ_HANDLED;
354 }
355
356 /*
357  * According to PICMG 2.1 R2.0, section 6.3.2, upon
358  * initialization, the system driver shall clear the
359  * INS bits of the cold-inserted devices.
360  */
361 static int
362 init_slots(int clear_ins)
363 {
364         struct slot *slot;
365         struct pci_dev *dev;
366
367         dbg("%s - enter", __func__);
368         down_read(&list_rwsem);
369         if (!slots) {
370                 up_read(&list_rwsem);
371                 return -1;
372         }
373         list_for_each_entry(slot, &slot_list, slot_list) {
374                 dbg("%s - looking at slot %s", __func__, slot_name(slot));
375                 if (clear_ins && cpci_check_and_clear_ins(slot))
376                         dbg("%s - cleared INS for slot %s",
377                             __func__, slot_name(slot));
378                 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0));
379                 if (dev) {
380                         if (update_adapter_status(slot->hotplug_slot, 1))
381                                 warn("failure to update adapter file");
382                         if (update_latch_status(slot->hotplug_slot, 1))
383                                 warn("failure to update latch file");
384                         slot->dev = dev;
385                 }
386         }
387         up_read(&list_rwsem);
388         dbg("%s - exit", __func__);
389         return 0;
390 }
391
392 static int
393 check_slots(void)
394 {
395         struct slot *slot;
396         int extracted;
397         int inserted;
398         u16 hs_csr;
399
400         down_read(&list_rwsem);
401         if (!slots) {
402                 up_read(&list_rwsem);
403                 err("no slots registered, shutting down");
404                 return -1;
405         }
406         extracted = inserted = 0;
407         list_for_each_entry(slot, &slot_list, slot_list) {
408                 dbg("%s - looking at slot %s", __func__, slot_name(slot));
409                 if (cpci_check_and_clear_ins(slot)) {
410                         /*
411                          * Some broken hardware (e.g. PLX 9054AB) asserts
412                          * ENUM# twice...
413                          */
414                         if (slot->dev) {
415                                 warn("slot %s already inserted",
416                                      slot_name(slot));
417                                 inserted++;
418                                 continue;
419                         }
420
421                         /* Process insertion */
422                         dbg("%s - slot %s inserted", __func__, slot_name(slot));
423
424                         /* GSM, debug */
425                         hs_csr = cpci_get_hs_csr(slot);
426                         dbg("%s - slot %s HS_CSR (1) = %04x",
427                             __func__, slot_name(slot), hs_csr);
428
429                         /* Configure device */
430                         dbg("%s - configuring slot %s",
431                             __func__, slot_name(slot));
432                         if (cpci_configure_slot(slot)) {
433                                 err("%s - could not configure slot %s",
434                                     __func__, slot_name(slot));
435                                 continue;
436                         }
437                         dbg("%s - finished configuring slot %s",
438                             __func__, slot_name(slot));
439
440                         /* GSM, debug */
441                         hs_csr = cpci_get_hs_csr(slot);
442                         dbg("%s - slot %s HS_CSR (2) = %04x",
443                             __func__, slot_name(slot), hs_csr);
444
445                         if (update_latch_status(slot->hotplug_slot, 1))
446                                 warn("failure to update latch file");
447
448                         if (update_adapter_status(slot->hotplug_slot, 1))
449                                 warn("failure to update adapter file");
450
451                         cpci_led_off(slot);
452
453                         /* GSM, debug */
454                         hs_csr = cpci_get_hs_csr(slot);
455                         dbg("%s - slot %s HS_CSR (3) = %04x",
456                             __func__, slot_name(slot), hs_csr);
457
458                         inserted++;
459                 } else if (cpci_check_ext(slot)) {
460                         /* Process extraction request */
461                         dbg("%s - slot %s extracted",
462                             __func__, slot_name(slot));
463
464                         /* GSM, debug */
465                         hs_csr = cpci_get_hs_csr(slot);
466                         dbg("%s - slot %s HS_CSR = %04x",
467                             __func__, slot_name(slot), hs_csr);
468
469                         if (!slot->extracting) {
470                                 if (update_latch_status(slot->hotplug_slot, 0)) {
471                                         warn("failure to update latch file");
472                                 }
473                                 slot->extracting = 1;
474                                 atomic_inc(&extracting);
475                         }
476                         extracted++;
477                 } else if (slot->extracting) {
478                         hs_csr = cpci_get_hs_csr(slot);
479                         if (hs_csr == 0xffff) {
480                                 /*
481                                  * Hmmm, we're likely hosed at this point, should we
482                                  * bother trying to tell the driver or not?
483                                  */
484                                 err("card in slot %s was improperly removed",
485                                     slot_name(slot));
486                                 if (update_adapter_status(slot->hotplug_slot, 0))
487                                         warn("failure to update adapter file");
488                                 slot->extracting = 0;
489                                 atomic_dec(&extracting);
490                         }
491                 }
492         }
493         up_read(&list_rwsem);
494         dbg("inserted=%d, extracted=%d, extracting=%d",
495             inserted, extracted, atomic_read(&extracting));
496         if (inserted || extracted)
497                 return extracted;
498         else if (!atomic_read(&extracting)) {
499                 err("cannot find ENUM# source, shutting down");
500                 return -1;
501         }
502         return 0;
503 }
504
505 /* This is the interrupt mode worker thread body */
506 static int
507 event_thread(void *data)
508 {
509         int rc;
510
511         dbg("%s - event thread started", __func__);
512         while (1) {
513                 dbg("event thread sleeping");
514                 set_current_state(TASK_INTERRUPTIBLE);
515                 schedule();
516                 if (kthread_should_stop())
517                         break;
518                 do {
519                         rc = check_slots();
520                         if (rc > 0) {
521                                 /* Give userspace a chance to handle extraction */
522                                 msleep(500);
523                         } else if (rc < 0) {
524                                 dbg("%s - error checking slots", __func__);
525                                 thread_finished = 1;
526                                 goto out;
527                         }
528                 } while (atomic_read(&extracting) && !kthread_should_stop());
529                 if (kthread_should_stop())
530                         break;
531
532                 /* Re-enable ENUM# interrupt */
533                 dbg("%s - re-enabling irq", __func__);
534                 controller->ops->enable_irq();
535         }
536  out:
537         return 0;
538 }
539
540 /* This is the polling mode worker thread body */
541 static int
542 poll_thread(void *data)
543 {
544         int rc;
545
546         while (1) {
547                 if (kthread_should_stop() || signal_pending(current))
548                         break;
549                 if (controller->ops->query_enum()) {
550                         do {
551                                 rc = check_slots();
552                                 if (rc > 0) {
553                                         /* Give userspace a chance to handle extraction */
554                                         msleep(500);
555                                 } else if (rc < 0) {
556                                         dbg("%s - error checking slots", __func__);
557                                         thread_finished = 1;
558                                         goto out;
559                                 }
560                         } while (atomic_read(&extracting) && !kthread_should_stop());
561                 }
562                 msleep(100);
563         }
564  out:
565         return 0;
566 }
567
568 static int
569 cpci_start_thread(void)
570 {
571         if (controller->irq)
572                 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd");
573         else
574                 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld");
575         if (IS_ERR(cpci_thread)) {
576                 err("Can't start up our thread");
577                 return PTR_ERR(cpci_thread);
578         }
579         thread_finished = 0;
580         return 0;
581 }
582
583 static void
584 cpci_stop_thread(void)
585 {
586         kthread_stop(cpci_thread);
587         thread_finished = 1;
588 }
589
590 int
591 cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
592 {
593         int status = 0;
594
595         if (controller)
596                 return -1;
597         if (!(new_controller && new_controller->ops))
598                 return -EINVAL;
599         if (new_controller->irq) {
600                 if (!(new_controller->ops->enable_irq &&
601                      new_controller->ops->disable_irq))
602                         status = -EINVAL;
603                 if (request_irq(new_controller->irq,
604                                cpci_hp_intr,
605                                new_controller->irq_flags,
606                                MY_NAME,
607                                new_controller->dev_id)) {
608                         err("Can't get irq %d for the hotplug cPCI controller",
609                             new_controller->irq);
610                         status = -ENODEV;
611                 }
612                 dbg("%s - acquired controller irq %d",
613                     __func__, new_controller->irq);
614         }
615         if (!status)
616                 controller = new_controller;
617         return status;
618 }
619 EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
620
621 static void
622 cleanup_slots(void)
623 {
624         struct slot *slot;
625         struct slot *tmp;
626
627         /*
628          * Unregister all of our slots with the pci_hotplug subsystem,
629          * and free up all memory that we had allocated.
630          */
631         down_write(&list_rwsem);
632         if (!slots)
633                 goto cleanup_null;
634         list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
635                 list_del(&slot->slot_list);
636                 pci_hp_deregister(slot->hotplug_slot);
637         }
638 cleanup_null:
639         up_write(&list_rwsem);
640         return;
641 }
642
643 int
644 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
645 {
646         int status = 0;
647
648         if (controller) {
649                 if (!thread_finished)
650                         cpci_stop_thread();
651                 if (controller->irq)
652                         free_irq(controller->irq, controller->dev_id);
653                 controller = NULL;
654                 cleanup_slots();
655         } else
656                 status = -ENODEV;
657         return status;
658 }
659 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
660
661 int
662 cpci_hp_start(void)
663 {
664         static int first = 1;
665         int status;
666
667         dbg("%s - enter", __func__);
668         if (!controller)
669                 return -ENODEV;
670
671         down_read(&list_rwsem);
672         if (list_empty(&slot_list)) {
673                 up_read(&list_rwsem);
674                 return -ENODEV;
675         }
676         up_read(&list_rwsem);
677
678         status = init_slots(first);
679         if (first)
680                 first = 0;
681         if (status)
682                 return status;
683
684         status = cpci_start_thread();
685         if (status)
686                 return status;
687         dbg("%s - thread started", __func__);
688
689         if (controller->irq) {
690                 /* Start enum interrupt processing */
691                 dbg("%s - enabling irq", __func__);
692                 controller->ops->enable_irq();
693         }
694         dbg("%s - exit", __func__);
695         return 0;
696 }
697 EXPORT_SYMBOL_GPL(cpci_hp_start);
698
699 int
700 cpci_hp_stop(void)
701 {
702         if (!controller)
703                 return -ENODEV;
704         if (controller->irq) {
705                 /* Stop enum interrupt processing */
706                 dbg("%s - disabling irq", __func__);
707                 controller->ops->disable_irq();
708         }
709         cpci_stop_thread();
710         return 0;
711 }
712 EXPORT_SYMBOL_GPL(cpci_hp_stop);
713
714 int __init
715 cpci_hotplug_init(int debug)
716 {
717         cpci_debug = debug;
718         return 0;
719 }
720
721 void __exit
722 cpci_hotplug_exit(void)
723 {
724         /*
725          * Clean everything up.
726          */
727         cpci_hp_stop();
728         cpci_hp_unregister_controller(controller);
729 }