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 static 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,
218 * i2c_verify_client - return parameter as i2c_client, or NULL
219 * @dev: device, probably from some driver model iterator
221 * When traversing the driver model tree, perhaps using driver model
222 * iterators like @device_for_each_child(), you can't assume very much
223 * about the nodes you find. Use this function to avoid oopses caused
224 * by wrongly treating some non-I2C device as an i2c_client.
226 struct i2c_client *i2c_verify_client(struct device *dev)
228 return (dev->bus == &i2c_bus_type)
232 EXPORT_SYMBOL(i2c_verify_client);
236 * i2c_new_device - instantiate an i2c device for use with a new style driver
237 * @adap: the adapter managing the device
238 * @info: describes one I2C device; bus_num is ignored
241 * Create a device to work with a new style i2c driver, where binding is
242 * handled through driver model probe()/remove() methods. This call is not
243 * appropriate for use by mainboad initialization logic, which usually runs
244 * during an arch_initcall() long before any i2c_adapter could exist.
246 * This returns the new i2c client, which may be saved for later use with
247 * i2c_unregister_device(); or NULL to indicate an error.
250 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
252 struct i2c_client *client;
255 client = kzalloc(sizeof *client, GFP_KERNEL);
259 client->adapter = adap;
261 client->dev.platform_data = info->platform_data;
262 device_init_wakeup(&client->dev, info->flags & I2C_CLIENT_WAKE);
264 client->flags = info->flags & ~I2C_CLIENT_WAKE;
265 client->addr = info->addr;
266 client->irq = info->irq;
268 strlcpy(client->name, info->type, sizeof(client->name));
270 /* a new style driver may be bound to this device when we
271 * return from this function, or any later moment (e.g. maybe
272 * hotplugging will load the driver module). and the device
273 * refcount model is the standard driver model one.
275 status = i2c_attach_client(client);
282 EXPORT_SYMBOL_GPL(i2c_new_device);
286 * i2c_unregister_device - reverse effect of i2c_new_device()
287 * @client: value returned from i2c_new_device()
290 void i2c_unregister_device(struct i2c_client *client)
292 struct i2c_adapter *adapter = client->adapter;
293 struct i2c_driver *driver = client->driver;
295 if (driver && !is_newstyle_driver(driver)) {
296 dev_err(&client->dev, "can't unregister devices "
297 "with legacy drivers\n");
302 mutex_lock(&adapter->clist_lock);
303 list_del(&client->list);
304 mutex_unlock(&adapter->clist_lock);
306 device_unregister(&client->dev);
308 EXPORT_SYMBOL_GPL(i2c_unregister_device);
311 static const struct i2c_device_id dummy_id[] = {
316 static int dummy_probe(struct i2c_client *client,
317 const struct i2c_device_id *id)
322 static int dummy_remove(struct i2c_client *client)
327 static struct i2c_driver dummy_driver = {
328 .driver.name = "dummy",
329 .probe = dummy_probe,
330 .remove = dummy_remove,
331 .id_table = dummy_id,
335 * i2c_new_dummy - return a new i2c device bound to a dummy driver
336 * @adapter: the adapter managing the device
337 * @address: seven bit address to be used
340 * This returns an I2C client bound to the "dummy" driver, intended for use
341 * with devices that consume multiple addresses. Examples of such chips
342 * include various EEPROMS (like 24c04 and 24c08 models).
344 * These dummy devices have two main uses. First, most I2C and SMBus calls
345 * except i2c_transfer() need a client handle; the dummy will be that handle.
346 * And second, this prevents the specified address from being bound to a
349 * This returns the new i2c client, which should be saved for later use with
350 * i2c_unregister_device(); or NULL to indicate an error.
353 i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
355 struct i2c_board_info info = {
356 I2C_BOARD_INFO("dummy", address),
359 return i2c_new_device(adapter, &info);
361 EXPORT_SYMBOL_GPL(i2c_new_dummy);
363 /* ------------------------------------------------------------------------- */
365 /* I2C bus adapters -- one roots each I2C or SMBUS segment */
367 static void i2c_adapter_dev_release(struct device *dev)
369 struct i2c_adapter *adap = to_i2c_adapter(dev);
370 complete(&adap->dev_released);
374 show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
376 struct i2c_adapter *adap = to_i2c_adapter(dev);
377 return sprintf(buf, "%s\n", adap->name);
380 static struct device_attribute i2c_adapter_attrs[] = {
381 __ATTR(name, S_IRUGO, show_adapter_name, NULL),
385 static struct class i2c_adapter_class = {
386 .owner = THIS_MODULE,
387 .name = "i2c-adapter",
388 .dev_attrs = i2c_adapter_attrs,
391 static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
393 struct i2c_devinfo *devinfo;
395 mutex_lock(&__i2c_board_lock);
396 list_for_each_entry(devinfo, &__i2c_board_list, list) {
397 if (devinfo->busnum == adapter->nr
398 && !i2c_new_device(adapter,
399 &devinfo->board_info))
400 printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n",
401 i2c_adapter_id(adapter),
402 devinfo->board_info.addr);
404 mutex_unlock(&__i2c_board_lock);
407 static int i2c_do_add_adapter(struct device_driver *d, void *data)
409 struct i2c_driver *driver = to_i2c_driver(d);
410 struct i2c_adapter *adap = data;
412 if (driver->attach_adapter) {
413 /* We ignore the return code; if it fails, too bad */
414 driver->attach_adapter(adap);
419 static int i2c_register_adapter(struct i2c_adapter *adap)
423 mutex_init(&adap->bus_lock);
424 mutex_init(&adap->clist_lock);
425 INIT_LIST_HEAD(&adap->clients);
427 mutex_lock(&core_lock);
429 /* Add the adapter to the driver core.
430 * If the parent pointer is not set up,
431 * we add this adapter to the host bus.
433 if (adap->dev.parent == NULL) {
434 adap->dev.parent = &platform_bus;
435 pr_debug("I2C adapter driver [%s] forgot to specify "
436 "physical device\n", adap->name);
438 sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
439 adap->dev.release = &i2c_adapter_dev_release;
440 adap->dev.class = &i2c_adapter_class;
441 res = device_register(&adap->dev);
445 dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
447 /* create pre-declared device nodes for new-style drivers */
448 if (adap->nr < __i2c_first_dynamic_bus_num)
449 i2c_scan_static_board_info(adap);
451 /* let legacy drivers scan this bus for matching devices */
452 dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
456 mutex_unlock(&core_lock);
460 idr_remove(&i2c_adapter_idr, adap->nr);
465 * i2c_add_adapter - declare i2c adapter, use dynamic bus number
466 * @adapter: the adapter to add
469 * This routine is used to declare an I2C adapter when its bus number
470 * doesn't matter. Examples: for I2C adapters dynamically added by
471 * USB links or PCI plugin cards.
473 * When this returns zero, a new bus number was allocated and stored
474 * in adap->nr, and the specified adapter became available for clients.
475 * Otherwise, a negative errno value is returned.
477 int i2c_add_adapter(struct i2c_adapter *adapter)
482 if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
485 mutex_lock(&core_lock);
486 /* "above" here means "above or equal to", sigh */
487 res = idr_get_new_above(&i2c_adapter_idr, adapter,
488 __i2c_first_dynamic_bus_num, &id);
489 mutex_unlock(&core_lock);
498 return i2c_register_adapter(adapter);
500 EXPORT_SYMBOL(i2c_add_adapter);
503 * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
504 * @adap: the adapter to register (with adap->nr initialized)
507 * This routine is used to declare an I2C adapter when its bus number
508 * matters. For example, use it for I2C adapters from system-on-chip CPUs,
509 * or otherwise built in to the system's mainboard, and where i2c_board_info
510 * is used to properly configure I2C devices.
512 * If no devices have pre-been declared for this bus, then be sure to
513 * register the adapter before any dynamically allocated ones. Otherwise
514 * the required bus ID may not be available.
516 * When this returns zero, the specified adapter became available for
517 * clients using the bus number provided in adap->nr. Also, the table
518 * of I2C devices pre-declared using i2c_register_board_info() is scanned,
519 * and the appropriate driver model device nodes are created. Otherwise, a
520 * negative errno value is returned.
522 int i2c_add_numbered_adapter(struct i2c_adapter *adap)
527 if (adap->nr & ~MAX_ID_MASK)
531 if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
534 mutex_lock(&core_lock);
535 /* "above" here means "above or equal to", sigh;
536 * we need the "equal to" result to force the result
538 status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
539 if (status == 0 && id != adap->nr) {
541 idr_remove(&i2c_adapter_idr, id);
543 mutex_unlock(&core_lock);
544 if (status == -EAGAIN)
548 status = i2c_register_adapter(adap);
551 EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
553 static int i2c_do_del_adapter(struct device_driver *d, void *data)
555 struct i2c_driver *driver = to_i2c_driver(d);
556 struct i2c_adapter *adapter = data;
559 if (!driver->detach_adapter)
561 res = driver->detach_adapter(adapter);
563 dev_err(&adapter->dev, "detach_adapter failed (%d) "
564 "for driver [%s]\n", res, driver->driver.name);
569 * i2c_del_adapter - unregister I2C adapter
570 * @adap: the adapter being unregistered
573 * This unregisters an I2C adapter which was previously registered
574 * by @i2c_add_adapter or @i2c_add_numbered_adapter.
576 int i2c_del_adapter(struct i2c_adapter *adap)
578 struct i2c_client *client, *_n;
581 mutex_lock(&core_lock);
583 /* First make sure that this adapter was ever added */
584 if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
585 pr_debug("i2c-core: attempting to delete unregistered "
586 "adapter [%s]\n", adap->name);
591 /* Tell drivers about this removal */
592 res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
597 /* detach any active clients. This must be done first, because
598 * it can fail; in which case we give up. */
599 list_for_each_entry_safe(client, _n, &adap->clients, list) {
600 struct i2c_driver *driver;
602 driver = client->driver;
604 /* new style, follow standard driver model */
605 if (!driver || is_newstyle_driver(driver)) {
606 i2c_unregister_device(client);
610 /* legacy drivers create and remove clients themselves */
611 if ((res = driver->detach_client(client))) {
612 dev_err(&adap->dev, "detach_client failed for client "
613 "[%s] at address 0x%02x\n", client->name,
619 /* clean up the sysfs representation */
620 init_completion(&adap->dev_released);
621 device_unregister(&adap->dev);
623 /* wait for sysfs to drop all references */
624 wait_for_completion(&adap->dev_released);
627 idr_remove(&i2c_adapter_idr, adap->nr);
629 dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
632 mutex_unlock(&core_lock);
635 EXPORT_SYMBOL(i2c_del_adapter);
638 /* ------------------------------------------------------------------------- */
640 static int __attach_adapter(struct device *dev, void *data)
642 struct i2c_adapter *adapter = to_i2c_adapter(dev);
643 struct i2c_driver *driver = data;
645 driver->attach_adapter(adapter);
651 * An i2c_driver is used with one or more i2c_client (device) nodes to access
652 * i2c slave chips, on a bus instance associated with some i2c_adapter. There
653 * are two models for binding the driver to its device: "new style" drivers
654 * follow the standard Linux driver model and just respond to probe() calls
655 * issued if the driver core sees they match(); "legacy" drivers create device
659 int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
663 /* new style driver methods can't mix with legacy ones */
664 if (is_newstyle_driver(driver)) {
665 if (driver->attach_adapter || driver->detach_adapter
666 || driver->detach_client) {
668 "i2c-core: driver [%s] is confused\n",
669 driver->driver.name);
674 /* add the driver to the list of i2c drivers in the driver core */
675 driver->driver.owner = owner;
676 driver->driver.bus = &i2c_bus_type;
678 /* for new style drivers, when registration returns the driver core
679 * will have called probe() for all matching-but-unbound devices.
681 res = driver_register(&driver->driver);
685 mutex_lock(&core_lock);
687 pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
689 /* legacy drivers scan i2c busses directly */
690 if (driver->attach_adapter)
691 class_for_each_device(&i2c_adapter_class, driver,
694 mutex_unlock(&core_lock);
697 EXPORT_SYMBOL(i2c_register_driver);
699 static int __detach_adapter(struct device *dev, void *data)
701 struct i2c_adapter *adapter = to_i2c_adapter(dev);
702 struct i2c_driver *driver = data;
704 /* Have a look at each adapter, if clients of this driver are still
705 * attached. If so, detach them to be able to kill the driver
708 if (driver->detach_adapter) {
709 if (driver->detach_adapter(adapter))
710 dev_err(&adapter->dev,
711 "detach_adapter failed for driver [%s]\n",
712 driver->driver.name);
714 struct i2c_client *client, *_n;
716 list_for_each_entry_safe(client, _n, &adapter->clients, list) {
717 if (client->driver != driver)
719 dev_dbg(&adapter->dev,
720 "detaching client [%s] at 0x%02x\n",
721 client->name, client->addr);
722 if (driver->detach_client(client))
723 dev_err(&adapter->dev, "detach_client "
724 "failed for client [%s] at 0x%02x\n",
725 client->name, client->addr);
733 * i2c_del_driver - unregister I2C driver
734 * @driver: the driver being unregistered
737 void i2c_del_driver(struct i2c_driver *driver)
739 mutex_lock(&core_lock);
742 if (!is_newstyle_driver(driver))
743 class_for_each_device(&i2c_adapter_class, driver,
746 driver_unregister(&driver->driver);
747 pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
749 mutex_unlock(&core_lock);
751 EXPORT_SYMBOL(i2c_del_driver);
753 /* ------------------------------------------------------------------------- */
755 static int __i2c_check_addr(struct device *dev, void *addrp)
757 struct i2c_client *client = i2c_verify_client(dev);
758 int addr = *(int *)addrp;
760 if (client && client->addr == addr)
765 static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
767 return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
770 int i2c_attach_client(struct i2c_client *client)
772 struct i2c_adapter *adapter = client->adapter;
775 client->dev.parent = &client->adapter->dev;
776 client->dev.bus = &i2c_bus_type;
779 client->dev.driver = &client->driver->driver;
781 if (client->driver && !is_newstyle_driver(client->driver)) {
782 client->dev.release = i2c_client_release;
783 client->dev.uevent_suppress = 1;
785 client->dev.release = i2c_client_dev_release;
787 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
788 "%d-%04x", i2c_adapter_id(adapter), client->addr);
789 res = device_register(&client->dev);
793 mutex_lock(&adapter->clist_lock);
794 list_add_tail(&client->list, &adapter->clients);
795 mutex_unlock(&adapter->clist_lock);
797 dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
798 client->name, client->dev.bus_id);
800 if (adapter->client_register) {
801 if (adapter->client_register(client)) {
802 dev_dbg(&adapter->dev, "client_register "
803 "failed for client [%s] at 0x%02x\n",
804 client->name, client->addr);
811 dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x "
812 "(%d)\n", client->name, client->addr, res);
815 EXPORT_SYMBOL(i2c_attach_client);
817 int i2c_detach_client(struct i2c_client *client)
819 struct i2c_adapter *adapter = client->adapter;
822 if (adapter->client_unregister) {
823 res = adapter->client_unregister(client);
825 dev_err(&client->dev,
826 "client_unregister [%s] failed, "
827 "client not detached\n", client->name);
832 mutex_lock(&adapter->clist_lock);
833 list_del(&client->list);
834 mutex_unlock(&adapter->clist_lock);
836 init_completion(&client->released);
837 device_unregister(&client->dev);
838 wait_for_completion(&client->released);
843 EXPORT_SYMBOL(i2c_detach_client);
846 * i2c_use_client - increments the reference count of the i2c client structure
847 * @client: the client being referenced
849 * Each live reference to a client should be refcounted. The driver model does
850 * that automatically as part of driver binding, so that most drivers don't
851 * need to do this explicitly: they hold a reference until they're unbound
854 * A pointer to the client with the incremented reference counter is returned.
856 struct i2c_client *i2c_use_client(struct i2c_client *client)
858 if (client && get_device(&client->dev))
862 EXPORT_SYMBOL(i2c_use_client);
865 * i2c_release_client - release a use of the i2c client structure
866 * @client: the client being no longer referenced
868 * Must be called when a user of a client is finished with it.
870 void i2c_release_client(struct i2c_client *client)
873 put_device(&client->dev);
875 EXPORT_SYMBOL(i2c_release_client);
882 static int i2c_cmd(struct device *dev, void *_arg)
884 struct i2c_client *client = i2c_verify_client(dev);
885 struct i2c_cmd_arg *arg = _arg;
887 if (client && client->driver && client->driver->command)
888 client->driver->command(client, arg->cmd, arg->arg);
892 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
894 struct i2c_cmd_arg cmd_arg;
898 device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
900 EXPORT_SYMBOL(i2c_clients_command);
902 static int __init i2c_init(void)
906 retval = bus_register(&i2c_bus_type);
909 retval = class_register(&i2c_adapter_class);
912 retval = i2c_add_driver(&dummy_driver);
918 class_unregister(&i2c_adapter_class);
920 bus_unregister(&i2c_bus_type);
924 static void __exit i2c_exit(void)
926 i2c_del_driver(&dummy_driver);
927 class_unregister(&i2c_adapter_class);
928 bus_unregister(&i2c_bus_type);
931 subsys_initcall(i2c_init);
932 module_exit(i2c_exit);
934 /* ----------------------------------------------------
935 * the functional interface to the i2c busses.
936 * ----------------------------------------------------
940 * i2c_transfer - execute a single or combined I2C message
941 * @adap: Handle to I2C bus
942 * @msgs: One or more messages to execute before STOP is issued to
943 * terminate the operation; each message begins with a START.
944 * @num: Number of messages to be executed.
946 * Returns negative errno, else the number of messages executed.
948 * Note that there is no requirement that each message be sent to
949 * the same slave address, although that is the most common model.
951 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
955 /* REVISIT the fault reporting model here is weak:
957 * - When we get an error after receiving N bytes from a slave,
958 * there is no way to report "N".
960 * - When we get a NAK after transmitting N bytes to a slave,
961 * there is no way to report "N" ... or to let the master
962 * continue executing the rest of this combined message, if
963 * that's the appropriate response.
965 * - When for example "num" is two and we successfully complete
966 * the first message but get an error part way through the
967 * second, it's unclear whether that should be reported as
968 * one (discarding status on the second message) or errno
969 * (discarding status on the first one).
972 if (adap->algo->master_xfer) {
974 for (ret = 0; ret < num; ret++) {
975 dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
976 "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
977 ? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
978 (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
982 if (in_atomic() || irqs_disabled()) {
983 ret = mutex_trylock(&adap->bus_lock);
985 /* I2C activity is ongoing. */
988 mutex_lock_nested(&adap->bus_lock, adap->level);
991 ret = adap->algo->master_xfer(adap,msgs,num);
992 mutex_unlock(&adap->bus_lock);
996 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
1000 EXPORT_SYMBOL(i2c_transfer);
1003 * i2c_master_send - issue a single I2C message in master transmit mode
1004 * @client: Handle to slave device
1005 * @buf: Data that will be written to the slave
1006 * @count: How many bytes to write
1008 * Returns negative errno, or else the number of bytes written.
1010 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
1013 struct i2c_adapter *adap=client->adapter;
1016 msg.addr = client->addr;
1017 msg.flags = client->flags & I2C_M_TEN;
1019 msg.buf = (char *)buf;
1021 ret = i2c_transfer(adap, &msg, 1);
1023 /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1024 transmitted, else error code. */
1025 return (ret == 1) ? count : ret;
1027 EXPORT_SYMBOL(i2c_master_send);
1030 * i2c_master_recv - issue a single I2C message in master receive mode
1031 * @client: Handle to slave device
1032 * @buf: Where to store data read from slave
1033 * @count: How many bytes to read
1035 * Returns negative errno, or else the number of bytes read.
1037 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
1039 struct i2c_adapter *adap=client->adapter;
1043 msg.addr = client->addr;
1044 msg.flags = client->flags & I2C_M_TEN;
1045 msg.flags |= I2C_M_RD;
1049 ret = i2c_transfer(adap, &msg, 1);
1051 /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1052 transmitted, else error code. */
1053 return (ret == 1) ? count : ret;
1055 EXPORT_SYMBOL(i2c_master_recv);
1057 /* ----------------------------------------------------
1058 * the i2c address scanning function
1059 * Will not work for 10-bit addresses!
1060 * ----------------------------------------------------
1062 static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
1063 int (*found_proc) (struct i2c_adapter *, int, int))
1067 /* Make sure the address is valid */
1068 if (addr < 0x03 || addr > 0x77) {
1069 dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
1074 /* Skip if already in use */
1075 if (i2c_check_addr(adapter, addr))
1078 /* Make sure there is something at this address, unless forced */
1080 if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1081 I2C_SMBUS_QUICK, NULL) < 0)
1084 /* prevent 24RF08 corruption */
1085 if ((addr & ~0x0f) == 0x50)
1086 i2c_smbus_xfer(adapter, addr, 0, 0, 0,
1087 I2C_SMBUS_QUICK, NULL);
1090 /* Finally call the custom detection function */
1091 err = found_proc(adapter, addr, kind);
1092 /* -ENODEV can be returned if there is a chip at the given address
1093 but it isn't supported by this chip driver. We catch it here as
1094 this isn't an error. */
1099 dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n",
1104 int i2c_probe(struct i2c_adapter *adapter,
1105 const struct i2c_client_address_data *address_data,
1106 int (*found_proc) (struct i2c_adapter *, int, int))
1109 int adap_id = i2c_adapter_id(adapter);
1111 /* Force entries are done first, and are not affected by ignore
1113 if (address_data->forces) {
1114 const unsigned short * const *forces = address_data->forces;
1117 for (kind = 0; forces[kind]; kind++) {
1118 for (i = 0; forces[kind][i] != I2C_CLIENT_END;
1120 if (forces[kind][i] == adap_id
1121 || forces[kind][i] == ANY_I2C_BUS) {
1122 dev_dbg(&adapter->dev, "found force "
1123 "parameter for adapter %d, "
1124 "addr 0x%02x, kind %d\n",
1125 adap_id, forces[kind][i + 1],
1127 err = i2c_probe_address(adapter,
1128 forces[kind][i + 1],
1137 /* Stop here if we can't use SMBUS_QUICK */
1138 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
1139 if (address_data->probe[0] == I2C_CLIENT_END
1140 && address_data->normal_i2c[0] == I2C_CLIENT_END)
1143 dev_warn(&adapter->dev, "SMBus Quick command not supported, "
1144 "can't probe for chips\n");
1148 /* Probe entries are done second, and are not affected by ignore
1150 for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
1151 if (address_data->probe[i] == adap_id
1152 || address_data->probe[i] == ANY_I2C_BUS) {
1153 dev_dbg(&adapter->dev, "found probe parameter for "
1154 "adapter %d, addr 0x%02x\n", adap_id,
1155 address_data->probe[i + 1]);
1156 err = i2c_probe_address(adapter,
1157 address_data->probe[i + 1],
1164 /* Normal entries are done last, unless shadowed by an ignore entry */
1165 for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
1169 for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
1171 if ((address_data->ignore[j] == adap_id ||
1172 address_data->ignore[j] == ANY_I2C_BUS)
1173 && address_data->ignore[j + 1]
1174 == address_data->normal_i2c[i]) {
1175 dev_dbg(&adapter->dev, "found ignore "
1176 "parameter for adapter %d, "
1177 "addr 0x%02x\n", adap_id,
1178 address_data->ignore[j + 1]);
1186 dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
1187 "addr 0x%02x\n", adap_id,
1188 address_data->normal_i2c[i]);
1189 err = i2c_probe_address(adapter, address_data->normal_i2c[i],
1197 EXPORT_SYMBOL(i2c_probe);
1200 i2c_new_probed_device(struct i2c_adapter *adap,
1201 struct i2c_board_info *info,
1202 unsigned short const *addr_list)
1206 /* Stop here if the bus doesn't support probing */
1207 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
1208 dev_err(&adap->dev, "Probing not supported\n");
1212 for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
1213 /* Check address validity */
1214 if (addr_list[i] < 0x03 || addr_list[i] > 0x77) {
1215 dev_warn(&adap->dev, "Invalid 7-bit address "
1216 "0x%02x\n", addr_list[i]);
1220 /* Check address availability */
1221 if (i2c_check_addr(adap, addr_list[i])) {
1222 dev_dbg(&adap->dev, "Address 0x%02x already in "
1223 "use, not probing\n", addr_list[i]);
1227 /* Test address responsiveness
1228 The default probe method is a quick write, but it is known
1229 to corrupt the 24RF08 EEPROMs due to a state machine bug,
1230 and could also irreversibly write-protect some EEPROMs, so
1231 for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte
1232 read instead. Also, some bus drivers don't implement
1233 quick write, so we fallback to a byte read it that case
1235 if ((addr_list[i] & ~0x07) == 0x30
1236 || (addr_list[i] & ~0x0f) == 0x50
1237 || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) {
1238 if (i2c_smbus_xfer(adap, addr_list[i], 0,
1240 I2C_SMBUS_BYTE, NULL) >= 0)
1243 if (i2c_smbus_xfer(adap, addr_list[i], 0,
1245 I2C_SMBUS_QUICK, NULL) >= 0)
1250 if (addr_list[i] == I2C_CLIENT_END) {
1251 dev_dbg(&adap->dev, "Probing failed, no device found\n");
1255 info->addr = addr_list[i];
1256 return i2c_new_device(adap, info);
1258 EXPORT_SYMBOL_GPL(i2c_new_probed_device);
1260 struct i2c_adapter* i2c_get_adapter(int id)
1262 struct i2c_adapter *adapter;
1264 mutex_lock(&core_lock);
1265 adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
1266 if (adapter && !try_module_get(adapter->owner))
1269 mutex_unlock(&core_lock);
1272 EXPORT_SYMBOL(i2c_get_adapter);
1274 void i2c_put_adapter(struct i2c_adapter *adap)
1276 module_put(adap->owner);
1278 EXPORT_SYMBOL(i2c_put_adapter);
1280 /* The SMBus parts */
1282 #define POLY (0x1070U << 3)
1288 for(i = 0; i < 8; i++) {
1293 return (u8)(data >> 8);
1296 /* Incremental CRC8 over count bytes in the array pointed to by p */
1297 static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
1301 for(i = 0; i < count; i++)
1302 crc = crc8((crc ^ p[i]) << 8);
1306 /* Assume a 7-bit address, which is reasonable for SMBus */
1307 static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
1309 /* The address will be sent first */
1310 u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD);
1311 pec = i2c_smbus_pec(pec, &addr, 1);
1313 /* The data buffer follows */
1314 return i2c_smbus_pec(pec, msg->buf, msg->len);
1317 /* Used for write only transactions */
1318 static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
1320 msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
1324 /* Return <0 on CRC error
1325 If there was a write before this read (most cases) we need to take the
1326 partial CRC from the write part into account.
1327 Note that this function does modify the message (we need to decrease the
1328 message length to hide the CRC byte from the caller). */
1329 static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
1331 u8 rpec = msg->buf[--msg->len];
1332 cpec = i2c_smbus_msg_pec(cpec, msg);
1335 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
1343 * i2c_smbus_read_byte - SMBus "receive byte" protocol
1344 * @client: Handle to slave device
1346 * This executes the SMBus "receive byte" protocol, returning negative errno
1347 * else the byte received from the device.
1349 s32 i2c_smbus_read_byte(struct i2c_client *client)
1351 union i2c_smbus_data data;
1354 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1356 I2C_SMBUS_BYTE, &data);
1357 return (status < 0) ? status : data.byte;
1359 EXPORT_SYMBOL(i2c_smbus_read_byte);
1362 * i2c_smbus_write_byte - SMBus "send byte" protocol
1363 * @client: Handle to slave device
1364 * @value: Byte to be sent
1366 * This executes the SMBus "send byte" protocol, returning negative errno
1367 * else zero on success.
1369 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
1371 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1372 I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
1374 EXPORT_SYMBOL(i2c_smbus_write_byte);
1377 * i2c_smbus_read_byte_data - SMBus "read byte" protocol
1378 * @client: Handle to slave device
1379 * @command: Byte interpreted by slave
1381 * This executes the SMBus "read byte" protocol, returning negative errno
1382 * else a data byte received from the device.
1384 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
1386 union i2c_smbus_data data;
1389 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1390 I2C_SMBUS_READ, command,
1391 I2C_SMBUS_BYTE_DATA, &data);
1392 return (status < 0) ? status : data.byte;
1394 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1397 * i2c_smbus_write_byte_data - SMBus "write byte" protocol
1398 * @client: Handle to slave device
1399 * @command: Byte interpreted by slave
1400 * @value: Byte being written
1402 * This executes the SMBus "write byte" protocol, returning negative errno
1403 * else zero on success.
1405 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
1407 union i2c_smbus_data data;
1409 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1410 I2C_SMBUS_WRITE,command,
1411 I2C_SMBUS_BYTE_DATA,&data);
1413 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1416 * i2c_smbus_read_word_data - SMBus "read word" protocol
1417 * @client: Handle to slave device
1418 * @command: Byte interpreted by slave
1420 * This executes the SMBus "read word" protocol, returning negative errno
1421 * else a 16-bit unsigned "word" received from the device.
1423 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
1425 union i2c_smbus_data data;
1428 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1429 I2C_SMBUS_READ, command,
1430 I2C_SMBUS_WORD_DATA, &data);
1431 return (status < 0) ? status : data.word;
1433 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1436 * i2c_smbus_write_word_data - SMBus "write word" protocol
1437 * @client: Handle to slave device
1438 * @command: Byte interpreted by slave
1439 * @value: 16-bit "word" being written
1441 * This executes the SMBus "write word" protocol, returning negative errno
1442 * else zero on success.
1444 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
1446 union i2c_smbus_data data;
1448 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1449 I2C_SMBUS_WRITE,command,
1450 I2C_SMBUS_WORD_DATA,&data);
1452 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1455 * i2c_smbus_read_block_data - SMBus "block read" protocol
1456 * @client: Handle to slave device
1457 * @command: Byte interpreted by slave
1458 * @values: Byte array into which data will be read; big enough to hold
1459 * the data returned by the slave. SMBus allows at most 32 bytes.
1461 * This executes the SMBus "block read" protocol, returning negative errno
1462 * else the number of data bytes in the slave's response.
1464 * Note that using this function requires that the client's adapter support
1465 * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
1466 * support this; its emulation through I2C messaging relies on a specific
1467 * mechanism (I2C_M_RECV_LEN) which may not be implemented.
1469 s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
1472 union i2c_smbus_data data;
1475 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1476 I2C_SMBUS_READ, command,
1477 I2C_SMBUS_BLOCK_DATA, &data);
1481 memcpy(values, &data.block[1], data.block[0]);
1482 return data.block[0];
1484 EXPORT_SYMBOL(i2c_smbus_read_block_data);
1487 * i2c_smbus_write_block_data - SMBus "block write" protocol
1488 * @client: Handle to slave device
1489 * @command: Byte interpreted by slave
1490 * @length: Size of data block; SMBus allows at most 32 bytes
1491 * @values: Byte array which will be written.
1493 * This executes the SMBus "block write" protocol, returning negative errno
1494 * else zero on success.
1496 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
1497 u8 length, const u8 *values)
1499 union i2c_smbus_data data;
1501 if (length > I2C_SMBUS_BLOCK_MAX)
1502 length = I2C_SMBUS_BLOCK_MAX;
1503 data.block[0] = length;
1504 memcpy(&data.block[1], values, length);
1505 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1506 I2C_SMBUS_WRITE,command,
1507 I2C_SMBUS_BLOCK_DATA,&data);
1509 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1511 /* Returns the number of read bytes */
1512 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
1513 u8 length, u8 *values)
1515 union i2c_smbus_data data;
1518 if (length > I2C_SMBUS_BLOCK_MAX)
1519 length = I2C_SMBUS_BLOCK_MAX;
1520 data.block[0] = length;
1521 status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1522 I2C_SMBUS_READ, command,
1523 I2C_SMBUS_I2C_BLOCK_DATA, &data);
1527 memcpy(values, &data.block[1], data.block[0]);
1528 return data.block[0];
1530 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1532 s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
1533 u8 length, const u8 *values)
1535 union i2c_smbus_data data;
1537 if (length > I2C_SMBUS_BLOCK_MAX)
1538 length = I2C_SMBUS_BLOCK_MAX;
1539 data.block[0] = length;
1540 memcpy(data.block + 1, values, length);
1541 return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1542 I2C_SMBUS_WRITE, command,
1543 I2C_SMBUS_I2C_BLOCK_DATA, &data);
1545 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1547 /* Simulate a SMBus command using the i2c protocol
1548 No checking of parameters is done! */
1549 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1550 unsigned short flags,
1551 char read_write, u8 command, int size,
1552 union i2c_smbus_data * data)
1554 /* So we need to generate a series of msgs. In the case of writing, we
1555 need to use only one message; when reading, we need two. We initialize
1556 most things with sane defaults, to keep the code below somewhat
1558 unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
1559 unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
1560 int num = read_write == I2C_SMBUS_READ?2:1;
1561 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1562 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1568 msgbuf0[0] = command;
1570 case I2C_SMBUS_QUICK:
1572 /* Special case: The read/write field is used as data */
1573 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1576 case I2C_SMBUS_BYTE:
1577 if (read_write == I2C_SMBUS_READ) {
1578 /* Special case: only a read! */
1579 msg[0].flags = I2C_M_RD | flags;
1583 case I2C_SMBUS_BYTE_DATA:
1584 if (read_write == I2C_SMBUS_READ)
1588 msgbuf0[1] = data->byte;
1591 case I2C_SMBUS_WORD_DATA:
1592 if (read_write == I2C_SMBUS_READ)
1596 msgbuf0[1] = data->word & 0xff;
1597 msgbuf0[2] = data->word >> 8;
1600 case I2C_SMBUS_PROC_CALL:
1601 num = 2; /* Special case */
1602 read_write = I2C_SMBUS_READ;
1605 msgbuf0[1] = data->word & 0xff;
1606 msgbuf0[2] = data->word >> 8;
1608 case I2C_SMBUS_BLOCK_DATA:
1609 if (read_write == I2C_SMBUS_READ) {
1610 msg[1].flags |= I2C_M_RECV_LEN;
1611 msg[1].len = 1; /* block length will be added by
1612 the underlying bus driver */
1614 msg[0].len = data->block[0] + 2;
1615 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1616 dev_err(&adapter->dev,
1617 "Invalid block write size %d\n",
1621 for (i = 1; i < msg[0].len; i++)
1622 msgbuf0[i] = data->block[i-1];
1625 case I2C_SMBUS_BLOCK_PROC_CALL:
1626 num = 2; /* Another special case */
1627 read_write = I2C_SMBUS_READ;
1628 if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
1629 dev_err(&adapter->dev,
1630 "Invalid block write size %d\n",
1634 msg[0].len = data->block[0] + 2;
1635 for (i = 1; i < msg[0].len; i++)
1636 msgbuf0[i] = data->block[i-1];
1637 msg[1].flags |= I2C_M_RECV_LEN;
1638 msg[1].len = 1; /* block length will be added by
1639 the underlying bus driver */
1641 case I2C_SMBUS_I2C_BLOCK_DATA:
1642 if (read_write == I2C_SMBUS_READ) {
1643 msg[1].len = data->block[0];
1645 msg[0].len = data->block[0] + 1;
1646 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
1647 dev_err(&adapter->dev,
1648 "Invalid block write size %d\n",
1652 for (i = 1; i <= data->block[0]; i++)
1653 msgbuf0[i] = data->block[i];
1657 dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
1661 i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
1662 && size != I2C_SMBUS_I2C_BLOCK_DATA);
1664 /* Compute PEC if first message is a write */
1665 if (!(msg[0].flags & I2C_M_RD)) {
1666 if (num == 1) /* Write only */
1667 i2c_smbus_add_pec(&msg[0]);
1668 else /* Write followed by read */
1669 partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
1671 /* Ask for PEC if last message is a read */
1672 if (msg[num-1].flags & I2C_M_RD)
1676 status = i2c_transfer(adapter, msg, num);
1680 /* Check PEC if last message is a read */
1681 if (i && (msg[num-1].flags & I2C_M_RD)) {
1682 status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
1687 if (read_write == I2C_SMBUS_READ)
1689 case I2C_SMBUS_BYTE:
1690 data->byte = msgbuf0[0];
1692 case I2C_SMBUS_BYTE_DATA:
1693 data->byte = msgbuf1[0];
1695 case I2C_SMBUS_WORD_DATA:
1696 case I2C_SMBUS_PROC_CALL:
1697 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1699 case I2C_SMBUS_I2C_BLOCK_DATA:
1700 for (i = 0; i < data->block[0]; i++)
1701 data->block[i+1] = msgbuf1[i];
1703 case I2C_SMBUS_BLOCK_DATA:
1704 case I2C_SMBUS_BLOCK_PROC_CALL:
1705 for (i = 0; i < msgbuf1[0] + 1; i++)
1706 data->block[i] = msgbuf1[i];
1713 * i2c_smbus_xfer - execute SMBus protocol operations
1714 * @adapter: Handle to I2C bus
1715 * @addr: Address of SMBus slave on that bus
1716 * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
1717 * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
1718 * @command: Byte interpreted by slave, for protocols which use such bytes
1719 * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
1720 * @data: Data to be read or written
1722 * This executes an SMBus protocol operation, and returns a negative
1723 * errno code else zero on success.
1725 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1726 char read_write, u8 command, int protocol,
1727 union i2c_smbus_data * data)
1731 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1733 if (adapter->algo->smbus_xfer) {
1734 mutex_lock(&adapter->bus_lock);
1735 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1736 command, protocol, data);
1737 mutex_unlock(&adapter->bus_lock);
1739 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1740 command, protocol, data);
1744 EXPORT_SYMBOL(i2c_smbus_xfer);
1746 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1747 MODULE_DESCRIPTION("I2C-Bus main module");
1748 MODULE_LICENSE("GPL");