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> */
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/errno.h>
27 #include <linux/slab.h>
28 #include <linux/i2c.h>
29 #include <linux/init.h>
30 #include <linux/idr.h>
31 #include <linux/seq_file.h>
32 #include <asm/uaccess.h>
35 static LIST_HEAD(adapters);
36 static LIST_HEAD(drivers);
37 static DECLARE_MUTEX(core_lists);
38 static DEFINE_IDR(i2c_adapter_idr);
40 /* match always succeeds, as we want the probe() to tell if we really accept this match */
41 static int i2c_device_match(struct device *dev, struct device_driver *drv)
46 static int i2c_bus_suspend(struct device * dev, pm_message_t state)
50 if (dev->driver && dev->driver->suspend)
51 rc = dev->driver->suspend(dev,state,0);
55 static int i2c_bus_resume(struct device * dev)
59 if (dev->driver && dev->driver->resume)
60 rc = dev->driver->resume(dev,0);
64 static struct bus_type i2c_bus_type = {
66 .match = i2c_device_match,
67 .suspend = i2c_bus_suspend,
68 .resume = i2c_bus_resume,
71 static int i2c_device_probe(struct device *dev)
76 static int i2c_device_remove(struct device *dev)
81 static void i2c_adapter_dev_release(struct device *dev)
83 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
84 complete(&adap->dev_released);
87 static struct device_driver i2c_adapter_driver = {
88 .name = "i2c_adapter",
90 .probe = i2c_device_probe,
91 .remove = i2c_device_remove,
94 static void i2c_adapter_class_dev_release(struct class_device *dev)
96 struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
97 complete(&adap->class_dev_released);
100 static struct class i2c_adapter_class = {
101 .name = "i2c-adapter",
102 .release = &i2c_adapter_class_dev_release,
105 static ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
107 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
108 return sprintf(buf, "%s\n", adap->name);
110 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
113 static void i2c_client_release(struct device *dev)
115 struct i2c_client *client = to_i2c_client(dev);
116 complete(&client->released);
119 static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
121 struct i2c_client *client = to_i2c_client(dev);
122 return sprintf(buf, "%s\n", client->name);
126 * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
127 * different type of a device. So beware if the DEVICE_ATTR() macro ever
128 * changes, this definition will also have to change.
130 static struct device_attribute dev_attr_client_name = {
131 .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
132 .show = &show_client_name,
136 /* ---------------------------------------------------
137 * registering functions
138 * ---------------------------------------------------
142 * i2c_add_adapter is called from within the algorithm layer,
143 * when a new hw adapter registers. A new device is register to be
144 * available for clients.
146 int i2c_add_adapter(struct i2c_adapter *adap)
149 struct list_head *item;
150 struct i2c_driver *driver;
154 if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
159 res = idr_get_new(&i2c_adapter_idr, NULL, &id);
166 adap->nr = id & MAX_ID_MASK;
167 init_MUTEX(&adap->bus_lock);
168 init_MUTEX(&adap->clist_lock);
169 list_add_tail(&adap->list,&adapters);
170 INIT_LIST_HEAD(&adap->clients);
172 /* Add the adapter to the driver core.
173 * If the parent pointer is not set up,
174 * we add this adapter to the host bus.
176 if (adap->dev.parent == NULL)
177 adap->dev.parent = &platform_bus;
178 sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
179 adap->dev.driver = &i2c_adapter_driver;
180 adap->dev.release = &i2c_adapter_dev_release;
181 device_register(&adap->dev);
182 device_create_file(&adap->dev, &dev_attr_name);
184 /* Add this adapter to the i2c_adapter class */
185 memset(&adap->class_dev, 0x00, sizeof(struct class_device));
186 adap->class_dev.dev = &adap->dev;
187 adap->class_dev.class = &i2c_adapter_class;
188 strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
189 class_device_register(&adap->class_dev);
191 /* inform drivers of new adapters */
192 list_for_each(item,&drivers) {
193 driver = list_entry(item, struct i2c_driver, list);
194 if (driver->flags & I2C_DF_NOTIFY)
195 /* We ignore the return code; if it fails, too bad */
196 driver->attach_adapter(adap);
199 dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
207 int i2c_del_adapter(struct i2c_adapter *adap)
209 struct list_head *item, *_n;
210 struct i2c_adapter *adap_from_list;
211 struct i2c_driver *driver;
212 struct i2c_client *client;
217 /* First make sure that this adapter was ever added */
218 list_for_each_entry(adap_from_list, &adapters, list) {
219 if (adap_from_list == adap)
222 if (adap_from_list != adap) {
223 pr_debug("I2C: Attempting to delete an unregistered "
229 list_for_each(item,&drivers) {
230 driver = list_entry(item, struct i2c_driver, list);
231 if (driver->detach_adapter)
232 if ((res = driver->detach_adapter(adap))) {
233 dev_warn(&adap->dev, "can't detach adapter "
234 "while detaching driver %s: driver not "
235 "detached!", driver->name);
240 /* detach any active clients. This must be done first, because
241 * it can fail; in which case we give upp. */
242 list_for_each_safe(item, _n, &adap->clients) {
243 client = list_entry(item, struct i2c_client, list);
245 /* detaching devices is unconditional of the set notify
246 * flag, as _all_ clients that reside on the adapter
247 * must be deleted, as this would cause invalid states.
249 if ((res=client->driver->detach_client(client))) {
250 dev_err(&adap->dev, "adapter not "
251 "unregistered, because client at "
252 "address %02x can't be detached. ",
258 /* clean up the sysfs representation */
259 init_completion(&adap->dev_released);
260 init_completion(&adap->class_dev_released);
261 class_device_unregister(&adap->class_dev);
262 device_remove_file(&adap->dev, &dev_attr_name);
263 device_unregister(&adap->dev);
264 list_del(&adap->list);
266 /* wait for sysfs to drop all references */
267 wait_for_completion(&adap->dev_released);
268 wait_for_completion(&adap->class_dev_released);
270 /* free dynamically allocated bus id */
271 idr_remove(&i2c_adapter_idr, adap->nr);
273 dev_dbg(&adap->dev, "adapter unregistered\n");
282 * What follows is the "upwards" interface: commands for talking to clients,
283 * which implement the functions to access the physical information of the
287 int i2c_add_driver(struct i2c_driver *driver)
289 struct list_head *item;
290 struct i2c_adapter *adapter;
295 /* add the driver to the list of i2c drivers in the driver core */
296 driver->driver.name = driver->name;
297 driver->driver.bus = &i2c_bus_type;
298 driver->driver.probe = i2c_device_probe;
299 driver->driver.remove = i2c_device_remove;
301 res = driver_register(&driver->driver);
305 list_add_tail(&driver->list,&drivers);
306 pr_debug("i2c-core: driver %s registered.\n", driver->name);
308 /* now look for instances of driver on our adapters */
309 if (driver->flags & I2C_DF_NOTIFY) {
310 list_for_each(item,&adapters) {
311 adapter = list_entry(item, struct i2c_adapter, list);
312 driver->attach_adapter(adapter);
321 int i2c_del_driver(struct i2c_driver *driver)
323 struct list_head *item1, *item2, *_n;
324 struct i2c_client *client;
325 struct i2c_adapter *adap;
331 /* Have a look at each adapter, if clients of this driver are still
332 * attached. If so, detach them to be able to kill the driver
335 pr_debug("i2c-core: unregister_driver - looking for clients.\n");
336 /* removing clients does not depend on the notify flag, else
337 * invalid operation might (will!) result, when using stale client
340 list_for_each(item1,&adapters) {
341 adap = list_entry(item1, struct i2c_adapter, list);
342 dev_dbg(&adap->dev, "examining adapter\n");
343 if (driver->detach_adapter) {
344 if ((res = driver->detach_adapter(adap))) {
345 dev_warn(&adap->dev, "while unregistering "
346 "dummy driver %s, adapter could "
347 "not be detached properly; driver "
348 "not unloaded!",driver->name);
352 list_for_each_safe(item2, _n, &adap->clients) {
353 client = list_entry(item2, struct i2c_client, list);
354 if (client->driver != driver)
356 pr_debug("i2c-core.o: detaching client %s:\n", client->name);
357 if ((res = driver->detach_client(client))) {
358 dev_err(&adap->dev, "while "
359 "unregistering driver "
360 "`%s', the client at "
363 "be detached; driver "
373 driver_unregister(&driver->driver);
374 list_del(&driver->list);
375 pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
382 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
384 struct list_head *item;
385 struct i2c_client *client;
387 list_for_each(item,&adapter->clients) {
388 client = list_entry(item, struct i2c_client, list);
389 if (client->addr == addr)
395 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
399 down(&adapter->clist_lock);
400 rval = __i2c_check_addr(adapter, addr);
401 up(&adapter->clist_lock);
406 int i2c_attach_client(struct i2c_client *client)
408 struct i2c_adapter *adapter = client->adapter;
410 down(&adapter->clist_lock);
411 if (__i2c_check_addr(client->adapter, client->addr)) {
412 up(&adapter->clist_lock);
415 list_add_tail(&client->list,&adapter->clients);
416 up(&adapter->clist_lock);
418 if (adapter->client_register) {
419 if (adapter->client_register(client)) {
420 dev_warn(&adapter->dev, "warning: client_register "
421 "seems to have failed for client %02x\n",
426 dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
429 if (client->flags & I2C_CLIENT_ALLOW_USE)
430 client->usage_count = 0;
432 client->dev.parent = &client->adapter->dev;
433 client->dev.driver = &client->driver->driver;
434 client->dev.bus = &i2c_bus_type;
435 client->dev.release = &i2c_client_release;
437 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
438 "%d-%04x", i2c_adapter_id(adapter), client->addr);
439 pr_debug("registering %s\n", client->dev.bus_id);
440 device_register(&client->dev);
441 device_create_file(&client->dev, &dev_attr_client_name);
447 int i2c_detach_client(struct i2c_client *client)
449 struct i2c_adapter *adapter = client->adapter;
452 if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
455 if (adapter->client_unregister) {
456 res = adapter->client_unregister(client);
458 dev_err(&client->dev,
459 "client_unregister [%s] failed, "
460 "client not detached", client->name);
465 down(&adapter->clist_lock);
466 list_del(&client->list);
467 init_completion(&client->released);
468 device_remove_file(&client->dev, &dev_attr_client_name);
469 device_unregister(&client->dev);
470 up(&adapter->clist_lock);
471 wait_for_completion(&client->released);
477 static int i2c_inc_use_client(struct i2c_client *client)
480 if (!try_module_get(client->driver->owner))
482 if (!try_module_get(client->adapter->owner)) {
483 module_put(client->driver->owner);
490 static void i2c_dec_use_client(struct i2c_client *client)
492 module_put(client->driver->owner);
493 module_put(client->adapter->owner);
496 int i2c_use_client(struct i2c_client *client)
500 ret = i2c_inc_use_client(client);
504 if (client->flags & I2C_CLIENT_ALLOW_USE) {
505 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
506 client->usage_count++;
507 else if (client->usage_count > 0)
510 client->usage_count++;
515 i2c_dec_use_client(client);
519 int i2c_release_client(struct i2c_client *client)
521 if(client->flags & I2C_CLIENT_ALLOW_USE) {
522 if(client->usage_count>0)
523 client->usage_count--;
525 pr_debug("i2c-core: %s used one too many times\n",
531 i2c_dec_use_client(client);
536 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
538 struct list_head *item;
539 struct i2c_client *client;
541 down(&adap->clist_lock);
542 list_for_each(item,&adap->clients) {
543 client = list_entry(item, struct i2c_client, list);
544 if (!try_module_get(client->driver->owner))
546 if (NULL != client->driver->command) {
547 up(&adap->clist_lock);
548 client->driver->command(client,cmd,arg);
549 down(&adap->clist_lock);
551 module_put(client->driver->owner);
553 up(&adap->clist_lock);
556 static int __init i2c_init(void)
560 retval = bus_register(&i2c_bus_type);
563 retval = driver_register(&i2c_adapter_driver);
566 return class_register(&i2c_adapter_class);
569 static void __exit i2c_exit(void)
571 class_unregister(&i2c_adapter_class);
572 driver_unregister(&i2c_adapter_driver);
573 bus_unregister(&i2c_bus_type);
576 subsys_initcall(i2c_init);
577 module_exit(i2c_exit);
579 /* ----------------------------------------------------
580 * the functional interface to the i2c busses.
581 * ----------------------------------------------------
584 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
588 if (adap->algo->master_xfer) {
590 for (ret = 0; ret < num; ret++) {
591 dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
592 "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?
593 'R' : 'W', msgs[ret].addr, msgs[ret].len);
597 down(&adap->bus_lock);
598 ret = adap->algo->master_xfer(adap,msgs,num);
603 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
608 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
611 struct i2c_adapter *adap=client->adapter;
614 if (client->adapter->algo->master_xfer) {
615 msg.addr = client->addr;
616 msg.flags = client->flags & I2C_M_TEN;
618 msg.buf = (char *)buf;
620 dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
623 down(&adap->bus_lock);
624 ret = adap->algo->master_xfer(adap,&msg,1);
627 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
628 * transmitted, else error code.
630 return (ret == 1 )? count : ret;
632 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
637 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
639 struct i2c_adapter *adap=client->adapter;
642 if (client->adapter->algo->master_xfer) {
643 msg.addr = client->addr;
644 msg.flags = client->flags & I2C_M_TEN;
645 msg.flags |= I2C_M_RD;
649 dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
652 down(&adap->bus_lock);
653 ret = adap->algo->master_xfer(adap,&msg,1);
656 dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
657 ret, count, client->addr);
659 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
660 * transmitted, else error code.
662 return (ret == 1 )? count : ret;
664 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
670 int i2c_control(struct i2c_client *client,
671 unsigned int cmd, unsigned long arg)
674 struct i2c_adapter *adap = client->adapter;
676 dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
685 if (adap->algo->algo_control!=NULL)
686 ret = adap->algo->algo_control(adap,cmd,arg);
691 /* ----------------------------------------------------
692 * the i2c address scanning function
693 * Will not work for 10-bit addresses!
694 * ----------------------------------------------------
696 int i2c_probe(struct i2c_adapter *adapter,
697 struct i2c_client_address_data *address_data,
698 int (*found_proc) (struct i2c_adapter *, int, int))
700 int addr,i,found,err;
701 int adap_id = i2c_adapter_id(adapter);
703 /* Forget it if we can't probe using SMBUS_QUICK */
704 if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
707 for (addr = 0x00; addr <= 0x7f; addr++) {
709 /* Skip if already in use */
710 if (i2c_check_addr(adapter,addr))
713 /* If it is in one of the force entries, we don't do any detection
717 for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 2) {
718 if (((adap_id == address_data->force[i]) ||
719 (address_data->force[i] == ANY_I2C_BUS)) &&
720 (addr == address_data->force[i+1])) {
721 dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
723 if ((err = found_proc(adapter,addr,0)))
731 /* If this address is in one of the ignores, we can forget about
734 !found && (address_data->ignore[i] != I2C_CLIENT_END);
736 if (((adap_id == address_data->ignore[i]) ||
737 ((address_data->ignore[i] == ANY_I2C_BUS))) &&
738 (addr == address_data->ignore[i+1])) {
739 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
740 "addr %04x\n", adap_id ,addr);
747 /* Now, we will do a detection, but only if it is in the normal or
750 !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
752 if (addr == address_data->normal_i2c[i]) {
754 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
755 "addr %02x\n", adap_id, addr);
760 !found && (address_data->probe[i] != I2C_CLIENT_END);
762 if (((adap_id == address_data->probe[i]) ||
763 ((address_data->probe[i] == ANY_I2C_BUS))) &&
764 (addr == address_data->probe[i+1])) {
766 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
767 "addr %04x\n", adap_id,addr);
773 /* OK, so we really should examine this address. First check
774 whether there is some client here at all! */
775 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
776 if ((err = found_proc(adapter,addr,-1)))
783 * return id number for a specific adapter
785 int i2c_adapter_id(struct i2c_adapter *adap)
790 struct i2c_adapter* i2c_get_adapter(int id)
792 struct list_head *item;
793 struct i2c_adapter *adapter;
796 list_for_each(item,&adapters) {
797 adapter = list_entry(item, struct i2c_adapter, list);
798 if (id == adapter->nr &&
799 try_module_get(adapter->owner)) {
808 void i2c_put_adapter(struct i2c_adapter *adap)
810 module_put(adap->owner);
813 /* The SMBus parts */
815 #define POLY (0x1070U << 3)
821 for(i = 0; i < 8; i++) {
826 return (u8)(data >> 8);
829 /* CRC over count bytes in the first array plus the bytes in the rest
830 array if it is non-null. rest[0] is the (length of rest) - 1
832 static u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
836 for(i = 0; i < count; i++)
837 crc = crc8((crc ^ first[i]) << 8);
839 for(i = 0; i <= rest[0]; i++)
840 crc = crc8((crc ^ rest[i]) << 8);
844 static u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
846 return i2c_smbus_partial_pec(0, count, first, rest);
849 /* Returns new "size" (transaction type)
850 Note that we convert byte to byte_data and byte_data to word_data
851 rather than invent new xxx_PEC transactions. */
852 static int i2c_smbus_add_pec(u16 addr, u8 command, int size,
853 union i2c_smbus_data *data)
861 data->byte = i2c_smbus_pec(2, buf, NULL);
862 size = I2C_SMBUS_BYTE_DATA;
864 case I2C_SMBUS_BYTE_DATA:
866 data->word = buf[2] ||
867 (i2c_smbus_pec(3, buf, NULL) << 8);
868 size = I2C_SMBUS_WORD_DATA;
870 case I2C_SMBUS_WORD_DATA:
873 case I2C_SMBUS_BLOCK_DATA:
874 data->block[data->block[0] + 1] =
875 i2c_smbus_pec(2, buf, data->block);
876 size = I2C_SMBUS_BLOCK_DATA_PEC;
882 static int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
883 union i2c_smbus_data *data)
885 u8 buf[3], rpec, cpec;
889 case I2C_SMBUS_BYTE_DATA:
890 buf[0] = (addr << 1) | 1;
891 cpec = i2c_smbus_pec(2, buf, NULL);
894 case I2C_SMBUS_WORD_DATA:
895 buf[0] = (addr << 1) | 1;
896 buf[2] = data->word & 0xff;
897 cpec = i2c_smbus_pec(3, buf, NULL);
898 rpec = data->word >> 8;
900 case I2C_SMBUS_WORD_DATA_PEC:
904 case I2C_SMBUS_PROC_CALL_PEC:
908 case I2C_SMBUS_BLOCK_DATA_PEC:
909 buf[0] = (addr << 1);
910 buf[2] = (addr << 1) | 1;
911 cpec = i2c_smbus_pec(3, buf, data->block);
912 rpec = data->block[data->block[0] + 1];
914 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
915 buf[0] = (addr << 1) | 1;
916 rpec = i2c_smbus_partial_pec(partial, 1,
918 cpec = data->block[data->block[0] + 1];
925 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
932 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
934 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
935 value,0,I2C_SMBUS_QUICK,NULL);
938 s32 i2c_smbus_read_byte(struct i2c_client *client)
940 union i2c_smbus_data data;
941 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
942 I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
945 return 0x0FF & data.byte;
948 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
950 union i2c_smbus_data data; /* only for PEC */
951 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
952 I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
955 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
957 union i2c_smbus_data data;
958 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
959 I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
962 return 0x0FF & data.byte;
965 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
967 union i2c_smbus_data data;
969 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
970 I2C_SMBUS_WRITE,command,
971 I2C_SMBUS_BYTE_DATA,&data);
974 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
976 union i2c_smbus_data data;
977 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
978 I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
981 return 0x0FFFF & data.word;
984 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
986 union i2c_smbus_data data;
988 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
989 I2C_SMBUS_WRITE,command,
990 I2C_SMBUS_WORD_DATA,&data);
993 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
994 u8 length, u8 *values)
996 union i2c_smbus_data data;
998 if (length > I2C_SMBUS_BLOCK_MAX)
999 length = I2C_SMBUS_BLOCK_MAX;
1000 for (i = 1; i <= length; i++)
1001 data.block[i] = values[i-1];
1002 data.block[0] = length;
1003 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1004 I2C_SMBUS_WRITE,command,
1005 I2C_SMBUS_BLOCK_DATA,&data);
1008 /* Returns the number of read bytes */
1009 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1011 union i2c_smbus_data data;
1013 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1014 I2C_SMBUS_READ,command,
1015 I2C_SMBUS_I2C_BLOCK_DATA,&data))
1018 for (i = 1; i <= data.block[0]; i++)
1019 values[i-1] = data.block[i];
1020 return data.block[0];
1024 /* Simulate a SMBus command using the i2c protocol
1025 No checking of parameters is done! */
1026 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1027 unsigned short flags,
1028 char read_write, u8 command, int size,
1029 union i2c_smbus_data * data)
1031 /* So we need to generate a series of msgs. In the case of writing, we
1032 need to use only one message; when reading, we need two. We initialize
1033 most things with sane defaults, to keep the code below somewhat
1035 unsigned char msgbuf0[34];
1036 unsigned char msgbuf1[34];
1037 int num = read_write == I2C_SMBUS_READ?2:1;
1038 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1039 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1043 msgbuf0[0] = command;
1045 case I2C_SMBUS_QUICK:
1047 /* Special case: The read/write field is used as data */
1048 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1051 case I2C_SMBUS_BYTE:
1052 if (read_write == I2C_SMBUS_READ) {
1053 /* Special case: only a read! */
1054 msg[0].flags = I2C_M_RD | flags;
1058 case I2C_SMBUS_BYTE_DATA:
1059 if (read_write == I2C_SMBUS_READ)
1063 msgbuf0[1] = data->byte;
1066 case I2C_SMBUS_WORD_DATA:
1067 if (read_write == I2C_SMBUS_READ)
1071 msgbuf0[1] = data->word & 0xff;
1072 msgbuf0[2] = (data->word >> 8) & 0xff;
1075 case I2C_SMBUS_PROC_CALL:
1076 num = 2; /* Special case */
1077 read_write = I2C_SMBUS_READ;
1080 msgbuf0[1] = data->word & 0xff;
1081 msgbuf0[2] = (data->word >> 8) & 0xff;
1083 case I2C_SMBUS_BLOCK_DATA:
1084 case I2C_SMBUS_BLOCK_DATA_PEC:
1085 if (read_write == I2C_SMBUS_READ) {
1086 dev_err(&adapter->dev, "Block read not supported "
1087 "under I2C emulation!\n");
1090 msg[0].len = data->block[0] + 2;
1091 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1092 dev_err(&adapter->dev, "smbus_access called with "
1093 "invalid block write size (%d)\n",
1097 if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1099 for (i = 1; i <= msg[0].len; i++)
1100 msgbuf0[i] = data->block[i-1];
1103 case I2C_SMBUS_BLOCK_PROC_CALL:
1104 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1105 dev_dbg(&adapter->dev, "Block process call not supported "
1106 "under I2C emulation!\n");
1108 case I2C_SMBUS_I2C_BLOCK_DATA:
1109 if (read_write == I2C_SMBUS_READ) {
1110 msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1112 msg[0].len = data->block[0] + 1;
1113 if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1114 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1115 "invalid block write size (%d)\n",
1119 for (i = 1; i <= data->block[0]; i++)
1120 msgbuf0[i] = data->block[i];
1124 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1129 if (i2c_transfer(adapter, msg, num) < 0)
1132 if (read_write == I2C_SMBUS_READ)
1134 case I2C_SMBUS_BYTE:
1135 data->byte = msgbuf0[0];
1137 case I2C_SMBUS_BYTE_DATA:
1138 data->byte = msgbuf1[0];
1140 case I2C_SMBUS_WORD_DATA:
1141 case I2C_SMBUS_PROC_CALL:
1142 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1144 case I2C_SMBUS_I2C_BLOCK_DATA:
1145 /* fixed at 32 for now */
1146 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1147 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1148 data->block[i+1] = msgbuf1[i];
1155 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1156 char read_write, u8 command, int size,
1157 union i2c_smbus_data * data)
1163 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1164 if((flags & I2C_CLIENT_PEC) &&
1165 !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1167 if(read_write == I2C_SMBUS_READ &&
1168 size == I2C_SMBUS_BLOCK_DATA)
1169 size = I2C_SMBUS_BLOCK_DATA_PEC;
1170 else if(size == I2C_SMBUS_PROC_CALL)
1171 size = I2C_SMBUS_PROC_CALL_PEC;
1172 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1173 i2c_smbus_add_pec(addr, command,
1174 I2C_SMBUS_BLOCK_DATA, data);
1175 partial = data->block[data->block[0] + 1];
1176 size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1177 } else if(read_write == I2C_SMBUS_WRITE &&
1178 size != I2C_SMBUS_QUICK &&
1179 size != I2C_SMBUS_I2C_BLOCK_DATA)
1180 size = i2c_smbus_add_pec(addr, command, size, data);
1183 if (adapter->algo->smbus_xfer) {
1184 down(&adapter->bus_lock);
1185 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1187 up(&adapter->bus_lock);
1189 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1192 if(res >= 0 && swpec &&
1193 size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1194 (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1195 size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1196 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1203 EXPORT_SYMBOL(i2c_add_adapter);
1204 EXPORT_SYMBOL(i2c_del_adapter);
1205 EXPORT_SYMBOL(i2c_add_driver);
1206 EXPORT_SYMBOL(i2c_del_driver);
1207 EXPORT_SYMBOL(i2c_attach_client);
1208 EXPORT_SYMBOL(i2c_detach_client);
1209 EXPORT_SYMBOL(i2c_use_client);
1210 EXPORT_SYMBOL(i2c_release_client);
1211 EXPORT_SYMBOL(i2c_clients_command);
1212 EXPORT_SYMBOL(i2c_check_addr);
1214 EXPORT_SYMBOL(i2c_master_send);
1215 EXPORT_SYMBOL(i2c_master_recv);
1216 EXPORT_SYMBOL(i2c_control);
1217 EXPORT_SYMBOL(i2c_transfer);
1218 EXPORT_SYMBOL(i2c_adapter_id);
1219 EXPORT_SYMBOL(i2c_get_adapter);
1220 EXPORT_SYMBOL(i2c_put_adapter);
1221 EXPORT_SYMBOL(i2c_probe);
1223 EXPORT_SYMBOL(i2c_smbus_xfer);
1224 EXPORT_SYMBOL(i2c_smbus_write_quick);
1225 EXPORT_SYMBOL(i2c_smbus_read_byte);
1226 EXPORT_SYMBOL(i2c_smbus_write_byte);
1227 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1228 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1229 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1230 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1231 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1232 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1234 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1235 MODULE_DESCRIPTION("I2C-Bus main module");
1236 MODULE_LICENSE("GPL");