1 /* i2c-core.c - a device driver for the iic-bus interface */
2 /* ------------------------------------------------------------------------- */
3 /* Copyright (C) 1995-99 Simon G. Vogl
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
18 /* ------------------------------------------------------------------------- */
20 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
21 All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
22 SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
23 Jean Delvare <khali@linux-fr.org> */
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/slab.h>
29 #include <linux/i2c.h>
30 #include <linux/init.h>
31 #include <linux/idr.h>
32 #include <linux/platform_device.h>
33 #include <linux/mutex.h>
34 #include <linux/completion.h>
35 #include <linux/hardirq.h>
36 #include <linux/irqflags.h>
37 #include <asm/uaccess.h>
42 static DEFINE_MUTEX(core_lock);
43 static DEFINE_IDR(i2c_adapter_idr);
45 #define is_newstyle_driver(d) ((d)->probe || (d)->remove)
47 /* ------------------------------------------------------------------------- */
49 static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
50 const struct i2c_client *client)
53 if (strcmp(client->name, id->name) == 0)
60 static int i2c_device_match(struct device *dev, struct device_driver *drv)
62 struct i2c_client *client = to_i2c_client(dev);
63 struct i2c_driver *driver = to_i2c_driver(drv);
65 /* make legacy i2c drivers bypass driver model probing entirely;
66 * such drivers scan each i2c adapter/bus themselves.
68 if (!is_newstyle_driver(driver))
71 /* match on an id table if there is one */
73 return i2c_match_id(driver->id_table, client) != NULL;
80 /* uevent helps with hotplug: modprobe -q $(MODALIAS) */
81 static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
83 struct i2c_client *client = to_i2c_client(dev);
85 /* by definition, legacy drivers can't hotplug */
89 if (add_uevent_var(env, "MODALIAS=%s%s",
90 I2C_MODULE_PREFIX, client->name))
92 dev_dbg(dev, "uevent\n");
97 #define i2c_device_uevent NULL
98 #endif /* CONFIG_HOTPLUG */
100 static int i2c_device_probe(struct device *dev)
102 struct i2c_client *client = to_i2c_client(dev);
103 struct i2c_driver *driver = to_i2c_driver(dev->driver);
106 if (!driver->probe || !driver->id_table)
108 client->driver = driver;
109 dev_dbg(dev, "probe\n");
111 status = driver->probe(client, i2c_match_id(driver->id_table, client));
113 client->driver = NULL;
117 static int i2c_device_remove(struct device *dev)
119 struct i2c_client *client = to_i2c_client(dev);
120 struct i2c_driver *driver;
126 driver = to_i2c_driver(dev->driver);
127 if (driver->remove) {
128 dev_dbg(dev, "remove\n");
129 status = driver->remove(client);
135 client->driver = NULL;
139 static void i2c_device_shutdown(struct device *dev)
141 struct i2c_driver *driver;
145 driver = to_i2c_driver(dev->driver);
146 if (driver->shutdown)
147 driver->shutdown(to_i2c_client(dev));
150 static int i2c_device_suspend(struct device * dev, pm_message_t mesg)
152 struct i2c_driver *driver;
156 driver = to_i2c_driver(dev->driver);
157 if (!driver->suspend)
159 return driver->suspend(to_i2c_client(dev), mesg);
162 static int i2c_device_resume(struct device * dev)
164 struct i2c_driver *driver;
168 driver = to_i2c_driver(dev->driver);
171 return driver->resume(to_i2c_client(dev));
174 static void i2c_client_release(struct device *dev)
176 struct i2c_client *client = to_i2c_client(dev);
177 complete(&client->released);
180 static void i2c_client_dev_release(struct device *dev)
182 kfree(to_i2c_client(dev));
185 static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
187 struct i2c_client *client = to_i2c_client(dev);
188 return sprintf(buf, "%s\n", client->name);
191 static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
193 struct i2c_client *client = to_i2c_client(dev);
194 return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
197 static struct device_attribute i2c_dev_attrs[] = {
198 __ATTR(name, S_IRUGO, show_client_name, NULL),
199 /* modalias helps coldplug: modprobe $(cat .../modalias) */
200 __ATTR(modalias, S_IRUGO, show_modalias, NULL),
204 struct bus_type i2c_bus_type = {
206 .dev_attrs = i2c_dev_attrs,
207 .match = i2c_device_match,
208 .uevent = i2c_device_uevent,
209 .probe = i2c_device_probe,
210 .remove = i2c_device_remove,
211 .shutdown = i2c_device_shutdown,
212 .suspend = i2c_device_suspend,
213 .resume = i2c_device_resume,
215 EXPORT_SYMBOL_GPL(i2c_bus_type);
219 * i2c_verify_client - return parameter as i2c_client, or NULL
220 * @dev: device, probably from some driver model iterator
222 * When traversing the driver model tree, perhaps using driver model
223 * iterators like @device_for_each_child(), you can't assume very much
224 * about the nodes you find. Use this function to avoid oopses caused
225 * by wrongly treating some non-I2C device as an i2c_client.
227 struct i2c_client *i2c_verify_client(struct device *dev)
229 return (dev->bus == &i2c_bus_type)
233 EXPORT_SYMBOL(i2c_verify_client);
237 * i2c_new_device - instantiate an i2c device for use with a new style driver
238 * @adap: the adapter managing the device
239 * @info: describes one I2C device; bus_num is ignored
242 * Create a device to work with a new style i2c driver, where binding is
243 * handled through driver model probe()/remove() methods. This call is not
244 * appropriate for use by mainboad initialization logic, which usually runs
245 * during an arch_initcall() long before any i2c_adapter could exist.
247 * This returns the new i2c client, which may be saved for later use with
248 * i2c_unregister_device(); or NULL to indicate an error.
251 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
253 struct i2c_client *client;
256 client = kzalloc(sizeof *client, GFP_KERNEL);
260 client->adapter = adap;
262 client->dev.platform_data = info->platform_data;
263 device_init_wakeup(&client->dev, info->flags & I2C_CLIENT_WAKE);
265 client->flags = info->flags & ~I2C_CLIENT_WAKE;
266 client->addr = info->addr;
267 client->irq = info->irq;
269 strlcpy(client->name, info->type, sizeof(client->name));
271 /* a new style driver may be bound to this device when we
272 * return from this function, or any later moment (e.g. maybe
273 * hotplugging will load the driver module). and the device
274 * refcount model is the standard driver model one.
276 status = i2c_attach_client(client);
283 EXPORT_SYMBOL_GPL(i2c_new_device);
287 * i2c_unregister_device - reverse effect of i2c_new_device()
288 * @client: value returned from i2c_new_device()
291 void i2c_unregister_device(struct i2c_client *client)
293 struct i2c_adapter *adapter = client->adapter;
294 struct i2c_driver *driver = client->driver;
296 if (driver && !is_newstyle_driver(driver)) {
297 dev_err(&client->dev, "can't unregister devices "
298 "with legacy drivers\n");
303 if (adapter->client_unregister) {
304 if (adapter->client_unregister(client)) {
305 dev_warn(&client->dev,
306 "client_unregister [%s] failed\n",
311 mutex_lock(&adapter->clist_lock);
312 list_del(&client->list);
313 mutex_unlock(&adapter->clist_lock);
315 device_unregister(&client->dev);
317 EXPORT_SYMBOL_GPL(i2c_unregister_device);
320 static const struct i2c_device_id dummy_id[] = {
325 static int dummy_probe(struct i2c_client *client,
326 const struct i2c_device_id *id)
331 static int dummy_remove(struct i2c_client *client)
336 static struct i2c_driver dummy_driver = {
337 .driver.name = "dummy",
338 .probe = dummy_probe,
339 .remove = dummy_remove,
340 .id_table = dummy_id,
344 * i2c_new_dummy - return a new i2c device bound to a dummy driver
345 * @adapter: the adapter managing the device
346 * @address: seven bit address to be used
349 * This returns an I2C client bound to the "dummy" driver, intended for use
350 * with devices that consume multiple addresses. Examples of such chips
351 * include various EEPROMS (like 24c04 and 24c08 models).
353 * These dummy devices have two main uses. First, most I2C and SMBus calls
354 * except i2c_transfer() need a client handle; the dummy will be that handle.
355 * And second, this prevents the specified address from being bound to a
358 * This returns the new i2c client, which should be saved for later use with
359 * i2c_unregister_device(); or NULL to indicate an error.
362 i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
364 struct i2c_board_info info = {
365 I2C_BOARD_INFO("dummy", address),
368 return i2c_new_device(adapter, &info);
370 EXPORT_SYMBOL_GPL(i2c_new_dummy);
372 /* ------------------------------------------------------------------------- */
374 /* I2C bus adapters -- one roots each I2C or SMBUS segment */
376 static void i2c_adapter_dev_release(struct device *dev)
378 struct i2c_adapter *adap = to_i2c_adapter(dev);
379 complete(&adap->dev_released);
383 show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
385 struct i2c_adapter *adap = to_i2c_adapter(dev);
386 return sprintf(buf, "%s\n", adap->name);
389 static struct device_attribute i2c_adapter_attrs[] = {
390 __ATTR(name, S_IRUGO, show_adapter_name, NULL),
394 static struct class i2c_adapter_class = {
395 .owner = THIS_MODULE,
396 .name = "i2c-adapter",
397 .dev_attrs = i2c_adapter_attrs,
400 static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
402 struct i2c_devinfo *devinfo;
404 mutex_lock(&__i2c_board_lock);
405 list_for_each_entry(devinfo, &__i2c_board_list, list) {
406 if (devinfo->busnum == adapter->nr
407 && !i2c_new_device(adapter,
408 &devinfo->board_info))
409 printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n",
410 i2c_adapter_id(adapter),
411 devinfo->board_info.addr);
413 mutex_unlock(&__i2c_board_lock);
416 static int i2c_do_add_adapter(struct device_driver *d, void *data)
418 struct i2c_driver *driver = to_i2c_driver(d);
419 struct i2c_adapter *adap = data;
421 if (driver->attach_adapter) {
422 /* We ignore the return code; if it fails, too bad */
423 driver->attach_adapter(adap);
428 static int i2c_register_adapter(struct i2c_adapter *adap)
432 mutex_init(&adap->bus_lock);
433 mutex_init(&adap->clist_lock);
434 INIT_LIST_HEAD(&adap->clients);
436 mutex_lock(&core_lock);
438 /* Add the adapter to the driver core.
439 * If the parent pointer is not set up,
440 * we add this adapter to the host bus.
442 if (adap->dev.parent == NULL) {
443 adap->dev.parent = &platform_bus;
444 pr_debug("I2C adapter driver [%s] forgot to specify "
445 "physical device\n", adap->name);
447 sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
448 adap->dev.release = &i2c_adapter_dev_release;
449 adap->dev.class = &i2c_adapter_class;
450 res = device_register(&adap->dev);
454 dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
456 /* create pre-declared device nodes for new-style drivers */
457 if (adap->nr < __i2c_first_dynamic_bus_num)
458 i2c_scan_static_board_info(adap);
460 /* let legacy drivers scan this bus for matching devices */
461 dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
465 mutex_unlock(&core_lock);
469 idr_remove(&i2c_adapter_idr, adap->nr);
474 * i2c_add_adapter - declare i2c adapter, use dynamic bus number
475 * @adapter: the adapter to add
478 * This routine is used to declare an I2C adapter when its bus number
479 * doesn't matter. Examples: for I2C adapters dynamically added by
480 * USB links or PCI plugin cards.
482 * When this returns zero, a new bus number was allocated and stored
483 * in adap->nr, and the specified adapter became available for clients.
484 * Otherwise, a negative errno value is returned.
486 int i2c_add_adapter(struct i2c_adapter *adapter)
491 if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
494 mutex_lock(&core_lock);
495 /* "above" here means "above or equal to", sigh */
496 res = idr_get_new_above(&i2c_adapter_idr, adapter,
497 __i2c_first_dynamic_bus_num, &id);
498 mutex_unlock(&core_lock);
507 return i2c_register_adapter(adapter);
509 EXPORT_SYMBOL(i2c_add_adapter);
512 * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
513 * @adap: the adapter to register (with adap->nr initialized)
516 * This routine is used to declare an I2C adapter when its bus number
517 * matters. For example, use it for I2C adapters from system-on-chip CPUs,
518 * or otherwise built in to the system's mainboard, and where i2c_board_info
519 * is used to properly configure I2C devices.
521 * If no devices have pre-been declared for this bus, then be sure to
522 * register the adapter before any dynamically allocated ones. Otherwise
523 * the required bus ID may not be available.
525 * When this returns zero, the specified adapter became available for
526 * clients using the bus number provided in adap->nr. Also, the table
527 * of I2C devices pre-declared using i2c_register_board_info() is scanned,
528 * and the appropriate driver model device nodes are created. Otherwise, a
529 * negative errno value is returned.
531 int i2c_add_numbered_adapter(struct i2c_adapter *adap)
536 if (adap->nr & ~MAX_ID_MASK)
540 if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
543 mutex_lock(&core_lock);
544 /* "above" here means "above or equal to", sigh;
545 * we need the "equal to" result to force the result
547 status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
548 if (status == 0 && id != adap->nr) {
550 idr_remove(&i2c_adapter_idr, id);
552 mutex_unlock(&core_lock);
553 if (status == -EAGAIN)
557 status = i2c_register_adapter(adap);
560 EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
562 static int i2c_do_del_adapter(struct device_driver *d, void *data)
564 struct i2c_driver *driver = to_i2c_driver(d);
565 struct i2c_adapter *adapter = data;
568 if (!driver->detach_adapter)
570 res = driver->detach_adapter(adapter);
572 dev_err(&adapter->dev, "detach_adapter failed (%d) "
573 "for driver [%s]\n", res, driver->driver.name);
578 * i2c_del_adapter - unregister I2C adapter
579 * @adap: the adapter being unregistered
582 * This unregisters an I2C adapter which was previously registered
583 * by @i2c_add_adapter or @i2c_add_numbered_adapter.
585 int i2c_del_adapter(struct i2c_adapter *adap)
587 struct i2c_client *client, *_n;
590 mutex_lock(&core_lock);
592 /* First make sure that this adapter was ever added */
593 if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
594 pr_debug("i2c-core: attempting to delete unregistered "
595 "adapter [%s]\n", adap->name);
600 /* Tell drivers about this removal */
601 res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
606 /* detach any active clients. This must be done first, because
607 * it can fail; in which case we give up. */
608 list_for_each_entry_safe(client, _n, &adap->clients, list) {
609 struct i2c_driver *driver;
611 driver = client->driver;
613 /* new style, follow standard driver model */
614 if (!driver || is_newstyle_driver(driver)) {
615 i2c_unregister_device(client);
619 /* legacy drivers create and remove clients themselves */
620 if ((res = driver->detach_client(client))) {
621 dev_err(&adap->dev, "detach_client failed for client "
622 "[%s] at address 0x%02x\n", client->name,
628 /* clean up the sysfs representation */
629 init_completion(&adap->dev_released);
630 device_unregister(&adap->dev);
632 /* wait for sysfs to drop all references */
633 wait_for_completion(&adap->dev_released);
636 idr_remove(&i2c_adapter_idr, adap->nr);
638 dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
641 mutex_unlock(&core_lock);
644 EXPORT_SYMBOL(i2c_del_adapter);
647 /* ------------------------------------------------------------------------- */
649 static int __attach_adapter(struct device *dev, void *data)
651 struct i2c_adapter *adapter = to_i2c_adapter(dev);
652 struct i2c_driver *driver = data;
654 driver->attach_adapter(adapter);
660 * An i2c_driver is used with one or more i2c_client (device) nodes to access
661 * i2c slave chips, on a bus instance associated with some i2c_adapter. There
662 * are two models for binding the driver to its device: "new style" drivers
663 * follow the standard Linux driver model and just respond to probe() calls
664 * issued if the driver core sees they match(); "legacy" drivers create device
668 int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
672 /* new style driver methods can't mix with legacy ones */
673 if (is_newstyle_driver(driver)) {
674 if (driver->attach_adapter || driver->detach_adapter
675 || driver->detach_client) {
677 "i2c-core: driver [%s] is confused\n",
678 driver->driver.name);
683 /* add the driver to the list of i2c drivers in the driver core */
684 driver->driver.owner = owner;
685 driver->driver.bus = &i2c_bus_type;
687 /* for new style drivers, when registration returns the driver core
688 * will have called probe() for all matching-but-unbound devices.
690 res = driver_register(&driver->driver);
694 mutex_lock(&core_lock);
696 pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
698 /* legacy drivers scan i2c busses directly */
699 if (driver->attach_adapter)
700 class_for_each_device(&i2c_adapter_class, driver,
703 mutex_unlock(&core_lock);
706 EXPORT_SYMBOL(i2c_register_driver);
708 static int __detach_adapter(struct device *dev, void *data)
710 struct i2c_adapter *adapter = to_i2c_adapter(dev);
711 struct i2c_driver *driver = data;
713 /* Have a look at each adapter, if clients of this driver are still
714 * attached. If so, detach them to be able to kill the driver
717 if (driver->detach_adapter) {
718 if (driver->detach_adapter(adapter))
719 dev_err(&adapter->dev,
720 "detach_adapter failed for driver [%s]\n",
721 driver->driver.name);
723 struct i2c_client *client, *_n;
725 list_for_each_entry_safe(client, _n, &adapter->clients, list) {
726 if (client->driver != driver)
728 dev_dbg(&adapter->dev,
729 "detaching client [%s] at 0x%02x\n",
730 client->name, client->addr);
731 if (driver->detach_client(client))
732 dev_err(&adapter->dev, "detach_client "
733 "failed for client [%s] at 0x%02x\n",
734 client->name, client->addr);
742 * i2c_del_driver - unregister I2C driver
743 * @driver: the driver being unregistered
746 void i2c_del_driver(struct i2c_driver *driver)
748 mutex_lock(&core_lock);
751 if (!is_newstyle_driver(driver))
752 class_for_each_device(&i2c_adapter_class, driver,
755 driver_unregister(&driver->driver);
756 pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
758 mutex_unlock(&core_lock);
760 EXPORT_SYMBOL(i2c_del_driver);
762 /* ------------------------------------------------------------------------- */
764 static int __i2c_check_addr(struct device *dev, void *addrp)
766 struct i2c_client *client = i2c_verify_client(dev);
767 int addr = *(int *)addrp;
769 if (client && client->addr == addr)
774 static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
776 return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
779 int i2c_attach_client(struct i2c_client *client)
781 struct i2c_adapter *adapter = client->adapter;
784 client->dev.parent = &client->adapter->dev;
785 client->dev.bus = &i2c_bus_type;
788 client->dev.driver = &client->driver->driver;
790 if (client->driver && !is_newstyle_driver(client->driver)) {
791 client->dev.release = i2c_client_release;
792 client->dev.uevent_suppress = 1;
794 client->dev.release = i2c_client_dev_release;
796 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
797 "%d-%04x", i2c_adapter_id(adapter), client->addr);
798 res = device_register(&client->dev);
802 mutex_lock(&adapter->clist_lock);
803 list_add_tail(&client->list, &adapter->clients);
804 mutex_unlock(&adapter->clist_lock);
806 dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
807 client->name, client->dev.bus_id);
809 if (adapter->client_register) {
810 if (adapter->client_register(client)) {
811 dev_dbg(&adapter->dev, "client_register "
812 "failed for client [%s] at 0x%02x\n",
813 client->name, client->addr);
820 dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x "
821 "(%d)\n", client->name, client->addr, res);
824 EXPORT_SYMBOL(i2c_attach_client);
826 int i2c_detach_client(struct i2c_client *client)
828 struct i2c_adapter *adapter = client->adapter;
831 if (adapter->client_unregister) {
832 res = adapter->client_unregister(client);
834 dev_err(&client->dev,
835 "client_unregister [%s] failed, "
836 "client not detached\n", client->name);
841 mutex_lock(&adapter->clist_lock);
842 list_del(&client->list);
843 mutex_unlock(&adapter->clist_lock);
845 init_completion(&client->released);
846 device_unregister(&client->dev);
847 wait_for_completion(&client->released);
852 EXPORT_SYMBOL(i2c_detach_client);
855 * i2c_use_client - increments the reference count of the i2c client structure
856 * @client: the client being referenced
858 * Each live reference to a client should be refcounted. The driver model does
859 * that automatically as part of driver binding, so that most drivers don't
860 * need to do this explicitly: they hold a reference until they're unbound
863 * A pointer to the client with the incremented reference counter is returned.
865 struct i2c_client *i2c_use_client(struct i2c_client *client)
867 if (client && get_device(&client->dev))
871 EXPORT_SYMBOL(i2c_use_client);
874 * i2c_release_client - release a use of the i2c client structure
875 * @client: the client being no longer referenced
877 * Must be called when a user of a client is finished with it.
879 void i2c_release_client(struct i2c_client *client)
882 put_device(&client->dev);
884 EXPORT_SYMBOL(i2c_release_client);
891 static int i2c_cmd(struct device *dev, void *_arg)
893 struct i2c_client *client = i2c_verify_client(dev);
894 struct i2c_cmd_arg *arg = _arg;
896 if (client && client->driver && client->driver->command)
897 client->driver->command(client, arg->cmd, arg->arg);
901 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
903 struct i2c_cmd_arg cmd_arg;
907 device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
909 EXPORT_SYMBOL(i2c_clients_command);
911 static int __init i2c_init(void)
915 retval = bus_register(&i2c_bus_type);
918 retval = class_register(&i2c_adapter_class);
921 retval = i2c_add_driver(&dummy_driver);
927 class_unregister(&i2c_adapter_class);
929 bus_unregister(&i2c_bus_type);
933 static void __exit i2c_exit(void)
935 i2c_del_driver(&dummy_driver);
936 class_unregister(&i2c_adapter_class);
937 bus_unregister(&i2c_bus_type);
940 subsys_initcall(i2c_init);
941 module_exit(i2c_exit);
943 /* ----------------------------------------------------
944 * the functional interface to the i2c busses.
945 * ----------------------------------------------------
949 * i2c_transfer - execute a single or combined I2C message
950 * @adap: Handle to I2C bus
951 * @msgs: One or more messages to execute before STOP is issued to
952 * terminate the operation; each message begins with a START.
953 * @num: Number of messages to be executed.
955 * Returns negative errno, else the number of messages executed.
957 * Note that there is no requirement that each message be sent to
958 * the same slave address, although that is the most common model.
960 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
964 /* REVISIT the fault reporting model here is weak:
966 * - When we get an error after receiving N bytes from a slave,
967 * there is no way to report "N".
969 * - When we get a NAK after transmitting N bytes to a slave,
970 * there is no way to report "N" ... or to let the master
971 * continue executing the rest of this combined message, if
972 * that's the appropriate response.
974 * - When for example "num" is two and we successfully complete
975 * the first message but get an error part way through the
976 * second, it's unclear whether that should be reported as
977 * one (discarding status on the second message) or errno
978 * (discarding status on the first one).
981 if (adap->algo->master_xfer) {
983 for (ret = 0; ret < num; ret++) {
984 dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
985 "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
986 ? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
987 (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
991 if (in_atomic() || irqs_disabled()) {
992 ret = mutex_trylock(&adap->bus_lock);
994 /* I2C activity is ongoing. */
997 mutex_lock_nested(&adap->bus_lock, adap->level);
1000 ret = adap->algo->master_xfer(adap,msgs,num);
1001 mutex_unlock(&adap->bus_lock);
1005 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
1009 EXPORT_SYMBOL(i2c_transfer);
1012 * i2c_master_send - issue a single I2C message in master transmit mode
1013 * @client: Handle to slave device
1014 * @buf: Data that will be written to the slave
1015 * @count: How many bytes to write
1017 * Returns negative errno, or else the number of bytes written.
1019 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
1022 struct i2c_adapter *adap=client->adapter;
1025 msg.addr = client->addr;
1026 msg.flags = client->flags & I2C_M_TEN;
1028 msg.buf = (char *)buf;
1030 ret = i2c_transfer(adap, &msg, 1);
1032 /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1033 transmitted, else error code. */
1034 return (ret == 1) ? count : ret;
1036 EXPORT_SYMBOL(i2c_master_send);
1039 * i2c_master_recv - issue a single I2C message in master receive mode
1040 * @client: Handle to slave device
1041 * @buf: Where to store data read from slave
1042 * @count: How many bytes to read
1044 * Returns negative errno, or else the number of bytes read.
1046 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
1048 struct i2c_adapter *adap=client->adapter;
1052 msg.addr = client->addr;
1053 msg.flags = client->flags & I2C_M_TEN;
1054 msg.flags |= I2C_M_RD;
1058 ret = i2c_transfer(adap, &msg, 1);
1060 /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1061 transmitted, else error code. */
1062 return (ret == 1) ? count : ret;
1064 EXPORT_SYMBOL(i2c_master_recv);
1066 /* ----------------------------------------------------
1067 * the i2c address scanning function
1068 * Will not work for 10-bit addresses!
1069 * ----------------------------------------------------
1071 static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
1072 int (*found_proc) (struct i2c_adapter *, int, int))
1076 /* Make sure the address is valid */
1077 if (addr < 0x03 || addr > 0x77) {
1078 dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
1083 /* Skip if already in use */
1084 if (i2c_check_addr(adapter, addr))
1087 /* Make sure there is something at this address, unless forced */
1089 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1090 I2C_SMBUS_QUICK, NULL) < 0)
1093 /* prevent 24RF08 corruption */
1094 if ((addr & ~0x0f) == 0x50)
1095 i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1096 I2C_SMBUS_QUICK, NULL);
1099 /* Finally call the custom detection function */
1100 err = found_proc(adapter, addr, kind);
1101 /* -ENODEV can be returned if there is a chip at the given address
1102 but it isn't supported by this chip driver. We catch it here as
1103 this isn't an error. */
1108 dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n",
1113 int i2c_probe(struct i2c_adapter *adapter,
1114 const struct i2c_client_address_data *address_data,
1115 int (*found_proc) (struct i2c_adapter *, int, int))
1118 int adap_id = i2c_adapter_id(adapter);
1120 /* Force entries are done first, and are not affected by ignore
1122 if (address_data->forces) {
1123 const unsigned short * const *forces = address_data->forces;
1126 for (kind = 0; forces[kind]; kind++) {
1127 for (i = 0; forces[kind][i] != I2C_CLIENT_END;
1129 if (forces[kind][i] == adap_id
1130 || forces[kind][i] == ANY_I2C_BUS) {
1131 dev_dbg(&adapter->dev, "found force "
1132 "parameter for adapter %d, "
1133 "addr 0x%02x, kind %d\n",
1134 adap_id, forces[kind][i + 1],
1136 err = i2c_probe_address(adapter,
1137 forces[kind][i + 1],
1146 /* Stop here if we can't use SMBUS_QUICK */
1147 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
1148 if (address_data->probe[0] == I2C_CLIENT_END
1149 && address_data->normal_i2c[0] == I2C_CLIENT_END)
1152 dev_warn(&adapter->dev, "SMBus Quick command not supported, "
1153 "can't probe for chips\n");
1157 /* Probe entries are done second, and are not affected by ignore
1159 for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
1160 if (address_data->probe[i] == adap_id
1161 || address_data->probe[i] == ANY_I2C_BUS) {
1162 dev_dbg(&adapter->dev, "found probe parameter for "
1163 "adapter %d, addr 0x%02x\n", adap_id,
1164 address_data->probe[i + 1]);
1165 err = i2c_probe_address(adapter,
1166 address_data->probe[i + 1],
1173 /* Normal entries are done last, unless shadowed by an ignore entry */
1174 for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
1178 for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
1180 if ((address_data->ignore[j] == adap_id ||
1181 address_data->ignore[j] == ANY_I2C_BUS)
1182 && address_data->ignore[j + 1]
1183 == address_data->normal_i2c[i]) {
1184 dev_dbg(&adapter->dev, "found ignore "
1185 "parameter for adapter %d, "
1186 "addr 0x%02x\n", adap_id,
1187 address_data->ignore[j + 1]);
1195 dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
1196 "addr 0x%02x\n", adap_id,
1197 address_data->normal_i2c[i]);
1198 err = i2c_probe_address(adapter, address_data->normal_i2c[i],
1206 EXPORT_SYMBOL(i2c_probe);
1209 i2c_new_probed_device(struct i2c_adapter *adap,
1210 struct i2c_board_info *info,
1211 unsigned short const *addr_list)
1215 /* Stop here if the bus doesn't support probing */
1216 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
1217 dev_err(&adap->dev, "Probing not supported\n");
1221 for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
1222 /* Check address validity */
1223 if (addr_list[i] < 0x03 || addr_list[i] > 0x77) {
1224 dev_warn(&adap->dev, "Invalid 7-bit address "
1225 "0x%02x\n", addr_list[i]);
1229 /* Check address availability */
1230 if (i2c_check_addr(adap, addr_list[i])) {
1231 dev_dbg(&adap->dev, "Address 0x%02x already in "
1232 "use, not probing\n", addr_list[i]);
1236 /* Test address responsiveness
1237 The default probe method is a quick write, but it is known
1238 to corrupt the 24RF08 EEPROMs due to a state machine bug,
1239 and could also irreversibly write-protect some EEPROMs, so
1240 for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte
1241 read instead. Also, some bus drivers don't implement
1242 quick write, so we fallback to a byte read it that case
1244 if ((addr_list[i] & ~0x07) == 0x30
1245 || (addr_list[i] & ~0x0f) == 0x50
1246 || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) {
1247 if (i2c_smbus_xfer(adap, addr_list[i], 0,
1249 I2C_SMBUS_BYTE, NULL) >= 0)
1252 if (i2c_smbus_xfer(adap, addr_list[i], 0,
1254 I2C_SMBUS_QUICK, NULL) >= 0)
1259 if (addr_list[i] == I2C_CLIENT_END) {
1260 dev_dbg(&adap->dev, "Probing failed, no device found\n");
1264 info->addr = addr_list[i];
1265 return i2c_new_device(adap, info);
1267 EXPORT_SYMBOL_GPL(i2c_new_probed_device);
1269 struct i2c_adapter* i2c_get_adapter(int id)
1271 struct i2c_adapter *adapter;
1273 mutex_lock(&core_lock);
1274 adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
1275 if (adapter && !try_module_get(adapter->owner))
1278 mutex_unlock(&core_lock);
1281 EXPORT_SYMBOL(i2c_get_adapter);
1283 void i2c_put_adapter(struct i2c_adapter *adap)
1285 module_put(adap->owner);
1287 EXPORT_SYMBOL(i2c_put_adapter);
1289 /* The SMBus parts */
1291 #define POLY (0x1070U << 3)
1297 for(i = 0; i < 8; i++) {
1302 return (u8)(data >> 8);
1305 /* Incremental CRC8 over count bytes in the array pointed to by p */
1306 static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
1310 for(i = 0; i < count; i++)
1311 crc = crc8((crc ^ p[i]) << 8);
1315 /* Assume a 7-bit address, which is reasonable for SMBus */
1316 static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
1318 /* The address will be sent first */
1319 u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD);
1320 pec = i2c_smbus_pec(pec, &addr, 1);
1322 /* The data buffer follows */
1323 return i2c_smbus_pec(pec, msg->buf, msg->len);
1326 /* Used for write only transactions */
1327 static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
1329 msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
1333 /* Return <0 on CRC error
1334 If there was a write before this read (most cases) we need to take the
1335 partial CRC from the write part into account.
1336 Note that this function does modify the message (we need to decrease the
1337 message length to hide the CRC byte from the caller). */
1338 static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
1340 u8 rpec = msg->buf[--msg->len];
1341 cpec = i2c_smbus_msg_pec(cpec, msg);
1344 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
1352 * i2c_smbus_read_byte - SMBus "receive byte" protocol
1353 * @client: Handle to slave device
1355 * This executes the SMBus "receive byte" protocol, returning negative errno
1356 * else the byte received from the device.
1358 s32 i2c_smbus_read_byte(struct i2c_client *client)
1360 union i2c_smbus_data data;
1363 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1365 I2C_SMBUS_BYTE, &data);
1366 return (status < 0) ? status : data.byte;
1368 EXPORT_SYMBOL(i2c_smbus_read_byte);
1371 * i2c_smbus_write_byte - SMBus "send byte" protocol
1372 * @client: Handle to slave device
1373 * @value: Byte to be sent
1375 * This executes the SMBus "send byte" protocol, returning negative errno
1376 * else zero on success.
1378 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
1380 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1381 I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
1383 EXPORT_SYMBOL(i2c_smbus_write_byte);
1386 * i2c_smbus_read_byte_data - SMBus "read byte" protocol
1387 * @client: Handle to slave device
1388 * @command: Byte interpreted by slave
1390 * This executes the SMBus "read byte" protocol, returning negative errno
1391 * else a data byte received from the device.
1393 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
1395 union i2c_smbus_data data;
1398 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1399 I2C_SMBUS_READ, command,
1400 I2C_SMBUS_BYTE_DATA, &data);
1401 return (status < 0) ? status : data.byte;
1403 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1406 * i2c_smbus_write_byte_data - SMBus "write byte" protocol
1407 * @client: Handle to slave device
1408 * @command: Byte interpreted by slave
1409 * @value: Byte being written
1411 * This executes the SMBus "write byte" protocol, returning negative errno
1412 * else zero on success.
1414 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
1416 union i2c_smbus_data data;
1418 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1419 I2C_SMBUS_WRITE,command,
1420 I2C_SMBUS_BYTE_DATA,&data);
1422 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1425 * i2c_smbus_read_word_data - SMBus "read word" protocol
1426 * @client: Handle to slave device
1427 * @command: Byte interpreted by slave
1429 * This executes the SMBus "read word" protocol, returning negative errno
1430 * else a 16-bit unsigned "word" received from the device.
1432 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
1434 union i2c_smbus_data data;
1437 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1438 I2C_SMBUS_READ, command,
1439 I2C_SMBUS_WORD_DATA, &data);
1440 return (status < 0) ? status : data.word;
1442 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1445 * i2c_smbus_write_word_data - SMBus "write word" protocol
1446 * @client: Handle to slave device
1447 * @command: Byte interpreted by slave
1448 * @value: 16-bit "word" being written
1450 * This executes the SMBus "write word" protocol, returning negative errno
1451 * else zero on success.
1453 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
1455 union i2c_smbus_data data;
1457 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1458 I2C_SMBUS_WRITE,command,
1459 I2C_SMBUS_WORD_DATA,&data);
1461 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1464 * i2c_smbus_read_block_data - SMBus "block read" protocol
1465 * @client: Handle to slave device
1466 * @command: Byte interpreted by slave
1467 * @values: Byte array into which data will be read; big enough to hold
1468 * the data returned by the slave. SMBus allows at most 32 bytes.
1470 * This executes the SMBus "block read" protocol, returning negative errno
1471 * else the number of data bytes in the slave's response.
1473 * Note that using this function requires that the client's adapter support
1474 * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
1475 * support this; its emulation through I2C messaging relies on a specific
1476 * mechanism (I2C_M_RECV_LEN) which may not be implemented.
1478 s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
1481 union i2c_smbus_data data;
1484 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1485 I2C_SMBUS_READ, command,
1486 I2C_SMBUS_BLOCK_DATA, &data);
1490 memcpy(values, &data.block[1], data.block[0]);
1491 return data.block[0];
1493 EXPORT_SYMBOL(i2c_smbus_read_block_data);
1496 * i2c_smbus_write_block_data - SMBus "block write" protocol
1497 * @client: Handle to slave device
1498 * @command: Byte interpreted by slave
1499 * @length: Size of data block; SMBus allows at most 32 bytes
1500 * @values: Byte array which will be written.
1502 * This executes the SMBus "block write" protocol, returning negative errno
1503 * else zero on success.
1505 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
1506 u8 length, const u8 *values)
1508 union i2c_smbus_data data;
1510 if (length > I2C_SMBUS_BLOCK_MAX)
1511 length = I2C_SMBUS_BLOCK_MAX;
1512 data.block[0] = length;
1513 memcpy(&data.block[1], values, length);
1514 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1515 I2C_SMBUS_WRITE,command,
1516 I2C_SMBUS_BLOCK_DATA,&data);
1518 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1520 /* Returns the number of read bytes */
1521 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
1522 u8 length, u8 *values)
1524 union i2c_smbus_data data;
1527 if (length > I2C_SMBUS_BLOCK_MAX)
1528 length = I2C_SMBUS_BLOCK_MAX;
1529 data.block[0] = length;
1530 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1531 I2C_SMBUS_READ, command,
1532 I2C_SMBUS_I2C_BLOCK_DATA, &data);
1536 memcpy(values, &data.block[1], data.block[0]);
1537 return data.block[0];
1539 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1541 s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
1542 u8 length, const u8 *values)
1544 union i2c_smbus_data data;
1546 if (length > I2C_SMBUS_BLOCK_MAX)
1547 length = I2C_SMBUS_BLOCK_MAX;
1548 data.block[0] = length;
1549 memcpy(data.block + 1, values, length);
1550 return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1551 I2C_SMBUS_WRITE, command,
1552 I2C_SMBUS_I2C_BLOCK_DATA, &data);
1554 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1556 /* Simulate a SMBus command using the i2c protocol
1557 No checking of parameters is done! */
1558 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1559 unsigned short flags,
1560 char read_write, u8 command, int size,
1561 union i2c_smbus_data * data)
1563 /* So we need to generate a series of msgs. In the case of writing, we
1564 need to use only one message; when reading, we need two. We initialize
1565 most things with sane defaults, to keep the code below somewhat
1567 unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
1568 unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
1569 int num = read_write == I2C_SMBUS_READ?2:1;
1570 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1571 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1577 msgbuf0[0] = command;
1579 case I2C_SMBUS_QUICK:
1581 /* Special case: The read/write field is used as data */
1582 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1585 case I2C_SMBUS_BYTE:
1586 if (read_write == I2C_SMBUS_READ) {
1587 /* Special case: only a read! */
1588 msg[0].flags = I2C_M_RD | flags;
1592 case I2C_SMBUS_BYTE_DATA:
1593 if (read_write == I2C_SMBUS_READ)
1597 msgbuf0[1] = data->byte;
1600 case I2C_SMBUS_WORD_DATA:
1601 if (read_write == I2C_SMBUS_READ)
1605 msgbuf0[1] = data->word & 0xff;
1606 msgbuf0[2] = data->word >> 8;
1609 case I2C_SMBUS_PROC_CALL:
1610 num = 2; /* Special case */
1611 read_write = I2C_SMBUS_READ;
1614 msgbuf0[1] = data->word & 0xff;
1615 msgbuf0[2] = data->word >> 8;
1617 case I2C_SMBUS_BLOCK_DATA:
1618 if (read_write == I2C_SMBUS_READ) {
1619 msg[1].flags |= I2C_M_RECV_LEN;
1620 msg[1].len = 1; /* block length will be added by
1621 the underlying bus driver */
1623 msg[0].len = data->block[0] + 2;
1624 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1625 dev_err(&adapter->dev,
1626 "Invalid block write size %d\n",
1630 for (i = 1; i < msg[0].len; i++)
1631 msgbuf0[i] = data->block[i-1];
1634 case I2C_SMBUS_BLOCK_PROC_CALL:
1635 num = 2; /* Another special case */
1636 read_write = I2C_SMBUS_READ;
1637 if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
1638 dev_err(&adapter->dev,
1639 "Invalid block write size %d\n",
1643 msg[0].len = data->block[0] + 2;
1644 for (i = 1; i < msg[0].len; i++)
1645 msgbuf0[i] = data->block[i-1];
1646 msg[1].flags |= I2C_M_RECV_LEN;
1647 msg[1].len = 1; /* block length will be added by
1648 the underlying bus driver */
1650 case I2C_SMBUS_I2C_BLOCK_DATA:
1651 if (read_write == I2C_SMBUS_READ) {
1652 msg[1].len = data->block[0];
1654 msg[0].len = data->block[0] + 1;
1655 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
1656 dev_err(&adapter->dev,
1657 "Invalid block write size %d\n",
1661 for (i = 1; i <= data->block[0]; i++)
1662 msgbuf0[i] = data->block[i];
1666 dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
1670 i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
1671 && size != I2C_SMBUS_I2C_BLOCK_DATA);
1673 /* Compute PEC if first message is a write */
1674 if (!(msg[0].flags & I2C_M_RD)) {
1675 if (num == 1) /* Write only */
1676 i2c_smbus_add_pec(&msg[0]);
1677 else /* Write followed by read */
1678 partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
1680 /* Ask for PEC if last message is a read */
1681 if (msg[num-1].flags & I2C_M_RD)
1685 status = i2c_transfer(adapter, msg, num);
1689 /* Check PEC if last message is a read */
1690 if (i && (msg[num-1].flags & I2C_M_RD)) {
1691 status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
1696 if (read_write == I2C_SMBUS_READ)
1698 case I2C_SMBUS_BYTE:
1699 data->byte = msgbuf0[0];
1701 case I2C_SMBUS_BYTE_DATA:
1702 data->byte = msgbuf1[0];
1704 case I2C_SMBUS_WORD_DATA:
1705 case I2C_SMBUS_PROC_CALL:
1706 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1708 case I2C_SMBUS_I2C_BLOCK_DATA:
1709 for (i = 0; i < data->block[0]; i++)
1710 data->block[i+1] = msgbuf1[i];
1712 case I2C_SMBUS_BLOCK_DATA:
1713 case I2C_SMBUS_BLOCK_PROC_CALL:
1714 for (i = 0; i < msgbuf1[0] + 1; i++)
1715 data->block[i] = msgbuf1[i];
1722 * i2c_smbus_xfer - execute SMBus protocol operations
1723 * @adapter: Handle to I2C bus
1724 * @addr: Address of SMBus slave on that bus
1725 * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
1726 * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
1727 * @command: Byte interpreted by slave, for protocols which use such bytes
1728 * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
1729 * @data: Data to be read or written
1731 * This executes an SMBus protocol operation, and returns a negative
1732 * errno code else zero on success.
1734 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1735 char read_write, u8 command, int protocol,
1736 union i2c_smbus_data * data)
1740 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1742 if (adapter->algo->smbus_xfer) {
1743 mutex_lock(&adapter->bus_lock);
1744 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1745 command, protocol, data);
1746 mutex_unlock(&adapter->bus_lock);
1748 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1749 command, protocol, data);
1753 EXPORT_SYMBOL(i2c_smbus_xfer);
1755 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1756 MODULE_DESCRIPTION("I2C-Bus main module");
1757 MODULE_LICENSE("GPL");