1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Device probing and sysfs code.
5 * Copyright (C) 2005-2006 Kristian Hoegsberg <krh@bitplanet.net>
9 #include <linux/ctype.h>
10 #include <linux/delay.h>
11 #include <linux/device.h>
12 #include <linux/errno.h>
13 #include <linux/firewire.h>
14 #include <linux/firewire-constants.h>
15 #include <linux/idr.h>
16 #include <linux/jiffies.h>
17 #include <linux/kobject.h>
18 #include <linux/list.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/random.h>
23 #include <linux/rwsem.h>
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/string.h>
27 #include <linux/workqueue.h>
29 #include <linux/atomic.h>
30 #include <asm/byteorder.h>
34 void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
37 ci->end = ci->p + (p[0] >> 16);
39 EXPORT_SYMBOL(fw_csr_iterator_init);
41 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
44 *value = *ci->p & 0xffffff;
46 return ci->p++ < ci->end;
48 EXPORT_SYMBOL(fw_csr_iterator_next);
50 static const u32 *search_leaf(const u32 *directory, int search_key)
52 struct fw_csr_iterator ci;
53 int last_key = 0, key, value;
55 fw_csr_iterator_init(&ci, directory);
56 while (fw_csr_iterator_next(&ci, &key, &value)) {
57 if (last_key == search_key &&
58 key == (CSR_DESCRIPTOR | CSR_LEAF))
59 return ci.p - 1 + value;
67 static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
69 unsigned int quadlets, i;
75 quadlets = min(block[0] >> 16, 256U);
79 if (block[1] != 0 || block[2] != 0)
80 /* unknown language/character set */
85 for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
86 c = block[i / 4] >> (24 - 8 * (i % 4));
97 * fw_csr_string() - reads a string from the configuration ROM
98 * @directory: e.g. root directory or unit directory
99 * @key: the key of the preceding directory entry
100 * @buf: where to put the string
101 * @size: size of @buf, in bytes
103 * The string is taken from a minimal ASCII text descriptor leaf just after the entry with the
104 * @key. The string is zero-terminated. An overlong string is silently truncated such that it
105 * and the zero byte fit into @size.
107 * Returns strlen(buf) or a negative error code.
109 int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
111 const u32 *leaf = search_leaf(directory, key);
115 return textual_leaf_to_string(leaf, buf, size);
117 EXPORT_SYMBOL(fw_csr_string);
119 static void get_ids(const u32 *directory, int *id)
121 struct fw_csr_iterator ci;
124 fw_csr_iterator_init(&ci, directory);
125 while (fw_csr_iterator_next(&ci, &key, &value)) {
127 case CSR_VENDOR: id[0] = value; break;
128 case CSR_MODEL: id[1] = value; break;
129 case CSR_SPECIFIER_ID: id[2] = value; break;
130 case CSR_VERSION: id[3] = value; break;
135 static void get_modalias_ids(struct fw_unit *unit, int *id)
137 get_ids(&fw_parent_device(unit)->config_rom[5], id);
138 get_ids(unit->directory, id);
141 static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
145 if (id[0] == id_table->vendor_id)
146 match |= IEEE1394_MATCH_VENDOR_ID;
147 if (id[1] == id_table->model_id)
148 match |= IEEE1394_MATCH_MODEL_ID;
149 if (id[2] == id_table->specifier_id)
150 match |= IEEE1394_MATCH_SPECIFIER_ID;
151 if (id[3] == id_table->version)
152 match |= IEEE1394_MATCH_VERSION;
154 return (match & id_table->match_flags) == id_table->match_flags;
157 static const struct ieee1394_device_id *unit_match(struct device *dev,
158 struct device_driver *drv)
160 const struct ieee1394_device_id *id_table =
161 container_of(drv, struct fw_driver, driver)->id_table;
162 int id[] = {0, 0, 0, 0};
164 get_modalias_ids(fw_unit(dev), id);
166 for (; id_table->match_flags != 0; id_table++)
167 if (match_ids(id_table, id))
173 static bool is_fw_unit(struct device *dev);
175 static int fw_unit_match(struct device *dev, struct device_driver *drv)
177 /* We only allow binding to fw_units. */
178 return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
181 static int fw_unit_probe(struct device *dev)
183 struct fw_driver *driver =
184 container_of(dev->driver, struct fw_driver, driver);
186 return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
189 static int fw_unit_remove(struct device *dev)
191 struct fw_driver *driver =
192 container_of(dev->driver, struct fw_driver, driver);
194 return driver->remove(fw_unit(dev)), 0;
197 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
199 int id[] = {0, 0, 0, 0};
201 get_modalias_ids(unit, id);
203 return snprintf(buffer, buffer_size,
204 "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
205 id[0], id[1], id[2], id[3]);
208 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
210 struct fw_unit *unit = fw_unit(dev);
213 get_modalias(unit, modalias, sizeof(modalias));
215 if (add_uevent_var(env, "MODALIAS=%s", modalias))
221 struct bus_type fw_bus_type = {
223 .match = fw_unit_match,
224 .probe = fw_unit_probe,
225 .remove = fw_unit_remove,
227 EXPORT_SYMBOL(fw_bus_type);
229 int fw_device_enable_phys_dma(struct fw_device *device)
231 int generation = device->generation;
233 /* device->node_id, accessed below, must not be older than generation */
236 return device->card->driver->enable_phys_dma(device->card,
240 EXPORT_SYMBOL(fw_device_enable_phys_dma);
242 struct config_rom_attribute {
243 struct device_attribute attr;
247 static ssize_t show_immediate(struct device *dev,
248 struct device_attribute *dattr, char *buf)
250 struct config_rom_attribute *attr =
251 container_of(dattr, struct config_rom_attribute, attr);
252 struct fw_csr_iterator ci;
254 int key, value, ret = -ENOENT;
256 down_read(&fw_device_rwsem);
259 dir = fw_unit(dev)->directory;
261 dir = fw_device(dev)->config_rom + 5;
263 fw_csr_iterator_init(&ci, dir);
264 while (fw_csr_iterator_next(&ci, &key, &value))
265 if (attr->key == key) {
266 ret = snprintf(buf, buf ? PAGE_SIZE : 0,
271 up_read(&fw_device_rwsem);
276 #define IMMEDIATE_ATTR(name, key) \
277 { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
279 static ssize_t show_text_leaf(struct device *dev,
280 struct device_attribute *dattr, char *buf)
282 struct config_rom_attribute *attr =
283 container_of(dattr, struct config_rom_attribute, attr);
289 down_read(&fw_device_rwsem);
292 dir = fw_unit(dev)->directory;
294 dir = fw_device(dev)->config_rom + 5;
297 bufsize = PAGE_SIZE - 1;
303 ret = fw_csr_string(dir, attr->key, buf, bufsize);
306 /* Strip trailing whitespace and add newline. */
307 while (ret > 0 && isspace(buf[ret - 1]))
309 strcpy(buf + ret, "\n");
313 up_read(&fw_device_rwsem);
318 #define TEXT_LEAF_ATTR(name, key) \
319 { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
321 static struct config_rom_attribute config_rom_attributes[] = {
322 IMMEDIATE_ATTR(vendor, CSR_VENDOR),
323 IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
324 IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
325 IMMEDIATE_ATTR(version, CSR_VERSION),
326 IMMEDIATE_ATTR(model, CSR_MODEL),
327 TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
328 TEXT_LEAF_ATTR(model_name, CSR_MODEL),
329 TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
332 static void init_fw_attribute_group(struct device *dev,
333 struct device_attribute *attrs,
334 struct fw_attribute_group *group)
336 struct device_attribute *attr;
339 for (j = 0; attrs[j].attr.name != NULL; j++)
340 group->attrs[j] = &attrs[j].attr;
342 for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
343 attr = &config_rom_attributes[i].attr;
344 if (attr->show(dev, attr, NULL) < 0)
346 group->attrs[j++] = &attr->attr;
349 group->attrs[j] = NULL;
350 group->groups[0] = &group->group;
351 group->groups[1] = NULL;
352 group->group.attrs = group->attrs;
353 dev->groups = (const struct attribute_group **) group->groups;
356 static ssize_t modalias_show(struct device *dev,
357 struct device_attribute *attr, char *buf)
359 struct fw_unit *unit = fw_unit(dev);
362 length = get_modalias(unit, buf, PAGE_SIZE);
363 strcpy(buf + length, "\n");
368 static ssize_t rom_index_show(struct device *dev,
369 struct device_attribute *attr, char *buf)
371 struct fw_device *device = fw_device(dev->parent);
372 struct fw_unit *unit = fw_unit(dev);
374 return snprintf(buf, PAGE_SIZE, "%d\n",
375 (int)(unit->directory - device->config_rom));
378 static struct device_attribute fw_unit_attributes[] = {
380 __ATTR_RO(rom_index),
384 static ssize_t config_rom_show(struct device *dev,
385 struct device_attribute *attr, char *buf)
387 struct fw_device *device = fw_device(dev);
390 down_read(&fw_device_rwsem);
391 length = device->config_rom_length * 4;
392 memcpy(buf, device->config_rom, length);
393 up_read(&fw_device_rwsem);
398 static ssize_t guid_show(struct device *dev,
399 struct device_attribute *attr, char *buf)
401 struct fw_device *device = fw_device(dev);
404 down_read(&fw_device_rwsem);
405 ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
406 device->config_rom[3], device->config_rom[4]);
407 up_read(&fw_device_rwsem);
412 static ssize_t is_local_show(struct device *dev,
413 struct device_attribute *attr, char *buf)
415 struct fw_device *device = fw_device(dev);
417 return sprintf(buf, "%u\n", device->is_local);
420 static int units_sprintf(char *buf, const u32 *directory)
422 struct fw_csr_iterator ci;
424 int specifier_id = 0;
427 fw_csr_iterator_init(&ci, directory);
428 while (fw_csr_iterator_next(&ci, &key, &value)) {
430 case CSR_SPECIFIER_ID:
431 specifier_id = value;
439 return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
442 static ssize_t units_show(struct device *dev,
443 struct device_attribute *attr, char *buf)
445 struct fw_device *device = fw_device(dev);
446 struct fw_csr_iterator ci;
447 int key, value, i = 0;
449 down_read(&fw_device_rwsem);
450 fw_csr_iterator_init(&ci, &device->config_rom[5]);
451 while (fw_csr_iterator_next(&ci, &key, &value)) {
452 if (key != (CSR_UNIT | CSR_DIRECTORY))
454 i += units_sprintf(&buf[i], ci.p + value - 1);
455 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
458 up_read(&fw_device_rwsem);
466 static struct device_attribute fw_device_attributes[] = {
467 __ATTR_RO(config_rom),
474 static int read_rom(struct fw_device *device,
475 int generation, int index, u32 *data)
477 u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
480 /* device->node_id, accessed below, must not be older than generation */
483 for (i = 10; i < 100; i += 10) {
484 rcode = fw_run_transaction(device->card,
485 TCODE_READ_QUADLET_REQUEST, device->node_id,
486 generation, device->max_speed, offset, data, 4);
487 if (rcode != RCODE_BUSY)
496 #define MAX_CONFIG_ROM_SIZE 256
499 * Read the bus info block, perform a speed probe, and read all of the rest of
500 * the config ROM. We do all this with a cached bus generation. If the bus
501 * generation changes under us, read_config_rom will fail and get retried.
502 * It's better to start all over in this case because the node from which we
503 * are reading the ROM may have changed the ROM during the reset.
504 * Returns either a result code or a negative error code.
506 static int read_config_rom(struct fw_device *device, int generation)
508 struct fw_card *card = device->card;
509 const u32 *old_rom, *new_rom;
512 int i, end, length, ret;
514 rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
515 sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
519 stack = &rom[MAX_CONFIG_ROM_SIZE];
520 memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
522 device->max_speed = SCODE_100;
524 /* First read the bus info block. */
525 for (i = 0; i < 5; i++) {
526 ret = read_rom(device, generation, i, &rom[i]);
527 if (ret != RCODE_COMPLETE)
530 * As per IEEE1212 7.2, during initialization, devices can
531 * reply with a 0 for the first quadlet of the config
532 * rom to indicate that they are booting (for example,
533 * if the firmware is on the disk of a external
534 * harddisk). In that case we just fail, and the
535 * retry mechanism will try again later.
537 if (i == 0 && rom[i] == 0) {
543 device->max_speed = device->node->max_speed;
546 * Determine the speed of
547 * - devices with link speed less than PHY speed,
548 * - devices with 1394b PHY (unless only connected to 1394a PHYs),
549 * - all devices if there are 1394b repeaters.
550 * Note, we cannot use the bus info block's link_spd as starting point
551 * because some buggy firmwares set it lower than necessary and because
552 * 1394-1995 nodes do not have the field.
554 if ((rom[2] & 0x7) < device->max_speed ||
555 device->max_speed == SCODE_BETA ||
556 card->beta_repeaters_present) {
559 /* for S1600 and S3200 */
560 if (device->max_speed == SCODE_BETA)
561 device->max_speed = card->link_speed;
563 while (device->max_speed > SCODE_100) {
564 if (read_rom(device, generation, 0, &dummy) ==
572 * Now parse the config rom. The config rom is a recursive
573 * directory structure so we parse it using a stack of
574 * references to the blocks that make up the structure. We
575 * push a reference to the root directory on the stack to
580 stack[sp++] = 0xc0000005;
583 * Pop the next block reference of the stack. The
584 * lower 24 bits is the offset into the config rom,
585 * the upper 8 bits are the type of the reference the
590 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
595 /* Read header quadlet for the block to get the length. */
596 ret = read_rom(device, generation, i, &rom[i]);
597 if (ret != RCODE_COMPLETE)
599 end = i + (rom[i] >> 16) + 1;
600 if (end > MAX_CONFIG_ROM_SIZE) {
602 * This block extends outside the config ROM which is
603 * a firmware bug. Ignore this whole block, i.e.
604 * simply set a fake block length of 0.
606 fw_err(card, "skipped invalid ROM block %x at %llx\n",
608 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
615 * Now read in the block. If this is a directory
616 * block, check the entries as we read them to see if
617 * it references another block, and push it in that case.
619 for (; i < end; i++) {
620 ret = read_rom(device, generation, i, &rom[i]);
621 if (ret != RCODE_COMPLETE)
624 if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
627 * Offset points outside the ROM. May be a firmware
628 * bug or an Extended ROM entry (IEEE 1212-2001 clause
629 * 7.7.18). Simply overwrite this pointer here by a
630 * fake immediate entry so that later iterators over
631 * the ROM don't have to check offsets all the time.
633 if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
635 "skipped unsupported ROM entry %x at %llx\n",
637 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
641 stack[sp++] = i + rom[i];
647 old_rom = device->config_rom;
648 new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
649 if (new_rom == NULL) {
654 down_write(&fw_device_rwsem);
655 device->config_rom = new_rom;
656 device->config_rom_length = length;
657 up_write(&fw_device_rwsem);
660 ret = RCODE_COMPLETE;
661 device->max_rec = rom[2] >> 12 & 0xf;
662 device->cmc = rom[2] >> 30 & 1;
663 device->irmc = rom[2] >> 31 & 1;
670 static void fw_unit_release(struct device *dev)
672 struct fw_unit *unit = fw_unit(dev);
674 fw_device_put(fw_parent_device(unit));
678 static struct device_type fw_unit_type = {
679 .uevent = fw_unit_uevent,
680 .release = fw_unit_release,
683 static bool is_fw_unit(struct device *dev)
685 return dev->type == &fw_unit_type;
688 static void create_units(struct fw_device *device)
690 struct fw_csr_iterator ci;
691 struct fw_unit *unit;
695 fw_csr_iterator_init(&ci, &device->config_rom[5]);
696 while (fw_csr_iterator_next(&ci, &key, &value)) {
697 if (key != (CSR_UNIT | CSR_DIRECTORY))
701 * Get the address of the unit directory and try to
702 * match the drivers id_tables against it.
704 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
708 unit->directory = ci.p + value - 1;
709 unit->device.bus = &fw_bus_type;
710 unit->device.type = &fw_unit_type;
711 unit->device.parent = &device->device;
712 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
714 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
715 ARRAY_SIZE(fw_unit_attributes) +
716 ARRAY_SIZE(config_rom_attributes));
717 init_fw_attribute_group(&unit->device,
719 &unit->attribute_group);
721 fw_device_get(device);
722 if (device_register(&unit->device) < 0) {
723 put_device(&unit->device);
729 static int shutdown_unit(struct device *device, void *data)
731 device_unregister(device);
737 * fw_device_rwsem acts as dual purpose mutex:
738 * - serializes accesses to fw_device_idr,
739 * - serializes accesses to fw_device.config_rom/.config_rom_length and
740 * fw_unit.directory, unless those accesses happen at safe occasions
742 DECLARE_RWSEM(fw_device_rwsem);
744 DEFINE_IDR(fw_device_idr);
747 struct fw_device *fw_device_get_by_devt(dev_t devt)
749 struct fw_device *device;
751 down_read(&fw_device_rwsem);
752 device = idr_find(&fw_device_idr, MINOR(devt));
754 fw_device_get(device);
755 up_read(&fw_device_rwsem);
760 struct workqueue_struct *fw_workqueue;
761 EXPORT_SYMBOL(fw_workqueue);
763 static void fw_schedule_device_work(struct fw_device *device,
766 queue_delayed_work(fw_workqueue, &device->work, delay);
770 * These defines control the retry behavior for reading the config
771 * rom. It shouldn't be necessary to tweak these; if the device
772 * doesn't respond to a config rom read within 10 seconds, it's not
773 * going to respond at all. As for the initial delay, a lot of
774 * devices will be able to respond within half a second after bus
775 * reset. On the other hand, it's not really worth being more
776 * aggressive than that, since it scales pretty well; if 10 devices
777 * are plugged in, they're all getting read within one second.
780 #define MAX_RETRIES 10
781 #define RETRY_DELAY (3 * HZ)
782 #define INITIAL_DELAY (HZ / 2)
783 #define SHUTDOWN_DELAY (2 * HZ)
785 static void fw_device_shutdown(struct work_struct *work)
787 struct fw_device *device =
788 container_of(work, struct fw_device, work.work);
789 int minor = MINOR(device->device.devt);
791 if (time_before64(get_jiffies_64(),
792 device->card->reset_jiffies + SHUTDOWN_DELAY)
793 && !list_empty(&device->card->link)) {
794 fw_schedule_device_work(device, SHUTDOWN_DELAY);
798 if (atomic_cmpxchg(&device->state,
800 FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
803 fw_device_cdev_remove(device);
804 device_for_each_child(&device->device, NULL, shutdown_unit);
805 device_unregister(&device->device);
807 down_write(&fw_device_rwsem);
808 idr_remove(&fw_device_idr, minor);
809 up_write(&fw_device_rwsem);
811 fw_device_put(device);
814 static void fw_device_release(struct device *dev)
816 struct fw_device *device = fw_device(dev);
817 struct fw_card *card = device->card;
821 * Take the card lock so we don't set this to NULL while a
822 * FW_NODE_UPDATED callback is being handled or while the
823 * bus manager work looks at this node.
825 spin_lock_irqsave(&card->lock, flags);
826 device->node->data = NULL;
827 spin_unlock_irqrestore(&card->lock, flags);
829 fw_node_put(device->node);
830 kfree(device->config_rom);
835 static struct device_type fw_device_type = {
836 .release = fw_device_release,
839 static bool is_fw_device(struct device *dev)
841 return dev->type == &fw_device_type;
844 static int update_unit(struct device *dev, void *data)
846 struct fw_unit *unit = fw_unit(dev);
847 struct fw_driver *driver = (struct fw_driver *)dev->driver;
849 if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
851 driver->update(unit);
858 static void fw_device_update(struct work_struct *work)
860 struct fw_device *device =
861 container_of(work, struct fw_device, work.work);
863 fw_device_cdev_update(device);
864 device_for_each_child(&device->device, NULL, update_unit);
868 * If a device was pending for deletion because its node went away but its
869 * bus info block and root directory header matches that of a newly discovered
870 * device, revive the existing fw_device.
871 * The newly allocated fw_device becomes obsolete instead.
873 static int lookup_existing_device(struct device *dev, void *data)
875 struct fw_device *old = fw_device(dev);
876 struct fw_device *new = data;
877 struct fw_card *card = new->card;
880 if (!is_fw_device(dev))
883 down_read(&fw_device_rwsem); /* serialize config_rom access */
884 spin_lock_irq(&card->lock); /* serialize node access */
886 if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
887 atomic_cmpxchg(&old->state,
889 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
890 struct fw_node *current_node = new->node;
891 struct fw_node *obsolete_node = old->node;
893 new->node = obsolete_node;
894 new->node->data = new;
895 old->node = current_node;
896 old->node->data = old;
898 old->max_speed = new->max_speed;
899 old->node_id = current_node->node_id;
900 smp_wmb(); /* update node_id before generation */
901 old->generation = card->generation;
902 old->config_rom_retries = 0;
903 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
905 old->workfn = fw_device_update;
906 fw_schedule_device_work(old, 0);
908 if (current_node == card->root_node)
909 fw_schedule_bm_work(card, 0);
914 spin_unlock_irq(&card->lock);
915 up_read(&fw_device_rwsem);
920 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
922 static void set_broadcast_channel(struct fw_device *device, int generation)
924 struct fw_card *card = device->card;
928 if (!card->broadcast_channel_allocated)
932 * The Broadcast_Channel Valid bit is required by nodes which want to
933 * transmit on this channel. Such transmissions are practically
934 * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required
935 * to be IRM capable and have a max_rec of 8 or more. We use this fact
936 * to narrow down to which nodes we send Broadcast_Channel updates.
938 if (!device->irmc || device->max_rec < 8)
942 * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
943 * Perform a read test first.
945 if (device->bc_implemented == BC_UNKNOWN) {
946 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
947 device->node_id, generation, device->max_speed,
948 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
952 if (data & cpu_to_be32(1 << 31)) {
953 device->bc_implemented = BC_IMPLEMENTED;
956 fallthrough; /* to case address error */
957 case RCODE_ADDRESS_ERROR:
958 device->bc_implemented = BC_UNIMPLEMENTED;
962 if (device->bc_implemented == BC_IMPLEMENTED) {
963 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
964 BROADCAST_CHANNEL_VALID);
965 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
966 device->node_id, generation, device->max_speed,
967 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
972 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
974 if (is_fw_device(dev))
975 set_broadcast_channel(fw_device(dev), (long)gen);
980 static void fw_device_init(struct work_struct *work)
982 struct fw_device *device =
983 container_of(work, struct fw_device, work.work);
984 struct fw_card *card = device->card;
985 struct device *revived_dev;
989 * All failure paths here set node->data to NULL, so that we
990 * don't try to do device_for_each_child() on a kfree()'d
994 ret = read_config_rom(device, device->generation);
995 if (ret != RCODE_COMPLETE) {
996 if (device->config_rom_retries < MAX_RETRIES &&
997 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
998 device->config_rom_retries++;
999 fw_schedule_device_work(device, RETRY_DELAY);
1001 if (device->node->link_on)
1002 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1004 fw_rcode_string(ret));
1005 if (device->node == card->root_node)
1006 fw_schedule_bm_work(card, 0);
1007 fw_device_release(&device->device);
1012 revived_dev = device_find_child(card->device,
1013 device, lookup_existing_device);
1015 put_device(revived_dev);
1016 fw_device_release(&device->device);
1021 device_initialize(&device->device);
1023 fw_device_get(device);
1024 down_write(&fw_device_rwsem);
1025 minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
1027 up_write(&fw_device_rwsem);
1032 device->device.bus = &fw_bus_type;
1033 device->device.type = &fw_device_type;
1034 device->device.parent = card->device;
1035 device->device.devt = MKDEV(fw_cdev_major, minor);
1036 dev_set_name(&device->device, "fw%d", minor);
1038 BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1039 ARRAY_SIZE(fw_device_attributes) +
1040 ARRAY_SIZE(config_rom_attributes));
1041 init_fw_attribute_group(&device->device,
1042 fw_device_attributes,
1043 &device->attribute_group);
1045 if (device_add(&device->device)) {
1046 fw_err(card, "failed to add device\n");
1047 goto error_with_cdev;
1050 create_units(device);
1053 * Transition the device to running state. If it got pulled
1054 * out from under us while we did the initialization work, we
1055 * have to shut down the device again here. Normally, though,
1056 * fw_node_event will be responsible for shutting it down when
1057 * necessary. We have to use the atomic cmpxchg here to avoid
1058 * racing with the FW_NODE_DESTROYED case in
1061 if (atomic_cmpxchg(&device->state,
1062 FW_DEVICE_INITIALIZING,
1063 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1064 device->workfn = fw_device_shutdown;
1065 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1067 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1068 dev_name(&device->device),
1069 device->config_rom[3], device->config_rom[4],
1070 1 << device->max_speed);
1071 device->config_rom_retries = 0;
1073 set_broadcast_channel(device, device->generation);
1075 add_device_randomness(&device->config_rom[3], 8);
1079 * Reschedule the IRM work if we just finished reading the
1080 * root node config rom. If this races with a bus reset we
1081 * just end up running the IRM work a couple of extra times -
1084 if (device->node == card->root_node)
1085 fw_schedule_bm_work(card, 0);
1090 down_write(&fw_device_rwsem);
1091 idr_remove(&fw_device_idr, minor);
1092 up_write(&fw_device_rwsem);
1094 fw_device_put(device); /* fw_device_idr's reference */
1096 put_device(&device->device); /* our reference */
1099 /* Reread and compare bus info block and header of root directory */
1100 static int reread_config_rom(struct fw_device *device, int generation,
1106 for (i = 0; i < 6; i++) {
1107 rcode = read_rom(device, generation, i, &q);
1108 if (rcode != RCODE_COMPLETE)
1111 if (i == 0 && q == 0)
1112 /* inaccessible (see read_config_rom); retry later */
1115 if (q != device->config_rom[i]) {
1117 return RCODE_COMPLETE;
1122 return RCODE_COMPLETE;
1125 static void fw_device_refresh(struct work_struct *work)
1127 struct fw_device *device =
1128 container_of(work, struct fw_device, work.work);
1129 struct fw_card *card = device->card;
1130 int ret, node_id = device->node_id;
1133 ret = reread_config_rom(device, device->generation, &changed);
1134 if (ret != RCODE_COMPLETE)
1135 goto failed_config_rom;
1138 if (atomic_cmpxchg(&device->state,
1139 FW_DEVICE_INITIALIZING,
1140 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1143 fw_device_update(work);
1144 device->config_rom_retries = 0;
1149 * Something changed. We keep things simple and don't investigate
1150 * further. We just destroy all previous units and create new ones.
1152 device_for_each_child(&device->device, NULL, shutdown_unit);
1154 ret = read_config_rom(device, device->generation);
1155 if (ret != RCODE_COMPLETE)
1156 goto failed_config_rom;
1158 fw_device_cdev_update(device);
1159 create_units(device);
1161 /* Userspace may want to re-read attributes. */
1162 kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1164 if (atomic_cmpxchg(&device->state,
1165 FW_DEVICE_INITIALIZING,
1166 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1169 fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1170 device->config_rom_retries = 0;
1174 if (device->config_rom_retries < MAX_RETRIES &&
1175 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1176 device->config_rom_retries++;
1177 fw_schedule_device_work(device, RETRY_DELAY);
1181 fw_notice(card, "giving up on refresh of device %s: %s\n",
1182 dev_name(&device->device), fw_rcode_string(ret));
1184 atomic_set(&device->state, FW_DEVICE_GONE);
1185 device->workfn = fw_device_shutdown;
1186 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1188 if (node_id == card->root_node->node_id)
1189 fw_schedule_bm_work(card, 0);
1192 static void fw_device_workfn(struct work_struct *work)
1194 struct fw_device *device = container_of(to_delayed_work(work),
1195 struct fw_device, work);
1196 device->workfn(work);
1199 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1201 struct fw_device *device;
1204 case FW_NODE_CREATED:
1206 * Attempt to scan the node, regardless whether its self ID has
1207 * the L (link active) flag set or not. Some broken devices
1208 * send L=0 but have an up-and-running link; others send L=1
1209 * without actually having a link.
1212 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1217 * Do minimal initialization of the device here, the
1218 * rest will happen in fw_device_init().
1220 * Attention: A lot of things, even fw_device_get(),
1221 * cannot be done before fw_device_init() finished!
1222 * You can basically just check device->state and
1223 * schedule work until then, but only while holding
1226 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1227 device->card = fw_card_get(card);
1228 device->node = fw_node_get(node);
1229 device->node_id = node->node_id;
1230 device->generation = card->generation;
1231 device->is_local = node == card->local_node;
1232 mutex_init(&device->client_list_mutex);
1233 INIT_LIST_HEAD(&device->client_list);
1236 * Set the node data to point back to this device so
1237 * FW_NODE_UPDATED callbacks can update the node_id
1238 * and generation for the device.
1240 node->data = device;
1243 * Many devices are slow to respond after bus resets,
1244 * especially if they are bus powered and go through
1245 * power-up after getting plugged in. We schedule the
1246 * first config rom scan half a second after bus reset.
1248 device->workfn = fw_device_init;
1249 INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1250 fw_schedule_device_work(device, INITIAL_DELAY);
1253 case FW_NODE_INITIATED_RESET:
1254 case FW_NODE_LINK_ON:
1255 device = node->data;
1259 device->node_id = node->node_id;
1260 smp_wmb(); /* update node_id before generation */
1261 device->generation = card->generation;
1262 if (atomic_cmpxchg(&device->state,
1264 FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1265 device->workfn = fw_device_refresh;
1266 fw_schedule_device_work(device,
1267 device->is_local ? 0 : INITIAL_DELAY);
1271 case FW_NODE_UPDATED:
1272 device = node->data;
1276 device->node_id = node->node_id;
1277 smp_wmb(); /* update node_id before generation */
1278 device->generation = card->generation;
1279 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1280 device->workfn = fw_device_update;
1281 fw_schedule_device_work(device, 0);
1285 case FW_NODE_DESTROYED:
1286 case FW_NODE_LINK_OFF:
1291 * Destroy the device associated with the node. There
1292 * are two cases here: either the device is fully
1293 * initialized (FW_DEVICE_RUNNING) or we're in the
1294 * process of reading its config rom
1295 * (FW_DEVICE_INITIALIZING). If it is fully
1296 * initialized we can reuse device->work to schedule a
1297 * full fw_device_shutdown(). If not, there's work
1298 * scheduled to read it's config rom, and we just put
1299 * the device in shutdown state to have that code fail
1300 * to create the device.
1302 device = node->data;
1303 if (atomic_xchg(&device->state,
1304 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1305 device->workfn = fw_device_shutdown;
1306 fw_schedule_device_work(device,
1307 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);