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 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 void i2c_adapter_dev_release(struct device *dev)
83 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
84 complete(&adap->dev_released);
87 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 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, adap, &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 dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
193 /* inform drivers of new adapters */
194 list_for_each(item,&drivers) {
195 driver = list_entry(item, struct i2c_driver, list);
196 if (driver->flags & I2C_DF_NOTIFY)
197 /* We ignore the return code; if it fails, too bad */
198 driver->attach_adapter(adap);
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-core: attempting to delete unregistered "
224 "adapter [%s]\n", adap->name);
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_err(&adap->dev, "detach_adapter failed "
234 "for driver [%s]\n", driver->name);
239 /* detach any active clients. This must be done first, because
240 * it can fail; in which case we give up. */
241 list_for_each_safe(item, _n, &adap->clients) {
242 client = list_entry(item, struct i2c_client, list);
244 /* detaching devices is unconditional of the set notify
245 * flag, as _all_ clients that reside on the adapter
246 * must be deleted, as this would cause invalid states.
248 if ((res=client->driver->detach_client(client))) {
249 dev_err(&adap->dev, "detach_client failed for client "
250 "[%s] at address 0x%02x\n", client->name,
256 /* clean up the sysfs representation */
257 init_completion(&adap->dev_released);
258 init_completion(&adap->class_dev_released);
259 class_device_unregister(&adap->class_dev);
260 device_remove_file(&adap->dev, &dev_attr_name);
261 device_unregister(&adap->dev);
262 list_del(&adap->list);
264 /* wait for sysfs to drop all references */
265 wait_for_completion(&adap->dev_released);
266 wait_for_completion(&adap->class_dev_released);
268 /* free dynamically allocated bus id */
269 idr_remove(&i2c_adapter_idr, adap->nr);
271 dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
280 * What follows is the "upwards" interface: commands for talking to clients,
281 * which implement the functions to access the physical information of the
285 int i2c_add_driver(struct i2c_driver *driver)
287 struct list_head *item;
288 struct i2c_adapter *adapter;
293 /* add the driver to the list of i2c drivers in the driver core */
294 driver->driver.name = driver->name;
295 driver->driver.bus = &i2c_bus_type;
296 driver->driver.probe = i2c_device_probe;
297 driver->driver.remove = i2c_device_remove;
299 res = driver_register(&driver->driver);
303 list_add_tail(&driver->list,&drivers);
304 pr_debug("i2c-core: driver [%s] registered\n", driver->name);
306 /* now look for instances of driver on our adapters */
307 if (driver->flags & I2C_DF_NOTIFY) {
308 list_for_each(item,&adapters) {
309 adapter = list_entry(item, struct i2c_adapter, list);
310 driver->attach_adapter(adapter);
319 int i2c_del_driver(struct i2c_driver *driver)
321 struct list_head *item1, *item2, *_n;
322 struct i2c_client *client;
323 struct i2c_adapter *adap;
329 /* Have a look at each adapter, if clients of this driver are still
330 * attached. If so, detach them to be able to kill the driver
333 * Removing clients does not depend on the notify flag, else
334 * invalid operation might (will!) result, when using stale client
337 list_for_each(item1,&adapters) {
338 adap = list_entry(item1, struct i2c_adapter, list);
339 if (driver->detach_adapter) {
340 if ((res = driver->detach_adapter(adap))) {
341 dev_err(&adap->dev, "detach_adapter failed "
342 "for driver [%s]\n", driver->name);
346 list_for_each_safe(item2, _n, &adap->clients) {
347 client = list_entry(item2, struct i2c_client, list);
348 if (client->driver != driver)
350 dev_dbg(&adap->dev, "detaching client [%s] "
351 "at 0x%02x\n", client->name,
353 if ((res = driver->detach_client(client))) {
354 dev_err(&adap->dev, "detach_client "
355 "failed for client [%s] at "
356 "0x%02x\n", client->name,
364 driver_unregister(&driver->driver);
365 list_del(&driver->list);
366 pr_debug("i2c-core: driver [%s] unregistered\n", driver->name);
373 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
375 struct list_head *item;
376 struct i2c_client *client;
378 list_for_each(item,&adapter->clients) {
379 client = list_entry(item, struct i2c_client, list);
380 if (client->addr == addr)
386 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
390 down(&adapter->clist_lock);
391 rval = __i2c_check_addr(adapter, addr);
392 up(&adapter->clist_lock);
397 int i2c_attach_client(struct i2c_client *client)
399 struct i2c_adapter *adapter = client->adapter;
401 down(&adapter->clist_lock);
402 if (__i2c_check_addr(client->adapter, client->addr)) {
403 up(&adapter->clist_lock);
406 list_add_tail(&client->list,&adapter->clients);
407 up(&adapter->clist_lock);
409 if (adapter->client_register) {
410 if (adapter->client_register(client)) {
411 dev_dbg(&adapter->dev, "client_register "
412 "failed for client [%s] at 0x%02x\n",
413 client->name, client->addr);
417 if (client->flags & I2C_CLIENT_ALLOW_USE)
418 client->usage_count = 0;
420 client->dev.parent = &client->adapter->dev;
421 client->dev.driver = &client->driver->driver;
422 client->dev.bus = &i2c_bus_type;
423 client->dev.release = &i2c_client_release;
425 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
426 "%d-%04x", i2c_adapter_id(adapter), client->addr);
427 dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
428 client->name, client->dev.bus_id);
429 device_register(&client->dev);
430 device_create_file(&client->dev, &dev_attr_client_name);
436 int i2c_detach_client(struct i2c_client *client)
438 struct i2c_adapter *adapter = client->adapter;
441 if ((client->flags & I2C_CLIENT_ALLOW_USE)
442 && (client->usage_count > 0)) {
443 dev_warn(&client->dev, "Client [%s] still busy, "
444 "can't detach\n", client->name);
448 if (adapter->client_unregister) {
449 res = adapter->client_unregister(client);
451 dev_err(&client->dev,
452 "client_unregister [%s] failed, "
453 "client not detached\n", client->name);
458 down(&adapter->clist_lock);
459 list_del(&client->list);
460 init_completion(&client->released);
461 device_remove_file(&client->dev, &dev_attr_client_name);
462 device_unregister(&client->dev);
463 up(&adapter->clist_lock);
464 wait_for_completion(&client->released);
470 static int i2c_inc_use_client(struct i2c_client *client)
473 if (!try_module_get(client->driver->owner))
475 if (!try_module_get(client->adapter->owner)) {
476 module_put(client->driver->owner);
483 static void i2c_dec_use_client(struct i2c_client *client)
485 module_put(client->driver->owner);
486 module_put(client->adapter->owner);
489 int i2c_use_client(struct i2c_client *client)
493 ret = i2c_inc_use_client(client);
497 if (client->flags & I2C_CLIENT_ALLOW_USE) {
498 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
499 client->usage_count++;
500 else if (client->usage_count > 0)
503 client->usage_count++;
508 i2c_dec_use_client(client);
512 int i2c_release_client(struct i2c_client *client)
514 if(client->flags & I2C_CLIENT_ALLOW_USE) {
515 if(client->usage_count>0)
516 client->usage_count--;
518 pr_debug("i2c-core: %s used one too many times\n",
524 i2c_dec_use_client(client);
529 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
531 struct list_head *item;
532 struct i2c_client *client;
534 down(&adap->clist_lock);
535 list_for_each(item,&adap->clients) {
536 client = list_entry(item, struct i2c_client, list);
537 if (!try_module_get(client->driver->owner))
539 if (NULL != client->driver->command) {
540 up(&adap->clist_lock);
541 client->driver->command(client,cmd,arg);
542 down(&adap->clist_lock);
544 module_put(client->driver->owner);
546 up(&adap->clist_lock);
549 static int __init i2c_init(void)
553 retval = bus_register(&i2c_bus_type);
556 retval = driver_register(&i2c_adapter_driver);
559 return class_register(&i2c_adapter_class);
562 static void __exit i2c_exit(void)
564 class_unregister(&i2c_adapter_class);
565 driver_unregister(&i2c_adapter_driver);
566 bus_unregister(&i2c_bus_type);
569 subsys_initcall(i2c_init);
570 module_exit(i2c_exit);
572 /* ----------------------------------------------------
573 * the functional interface to the i2c busses.
574 * ----------------------------------------------------
577 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
581 if (adap->algo->master_xfer) {
583 for (ret = 0; ret < num; ret++) {
584 dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
585 "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?
586 'R' : 'W', msgs[ret].addr, msgs[ret].len);
590 down(&adap->bus_lock);
591 ret = adap->algo->master_xfer(adap,msgs,num);
596 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
601 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
604 struct i2c_adapter *adap=client->adapter;
607 msg.addr = client->addr;
608 msg.flags = client->flags & I2C_M_TEN;
610 msg.buf = (char *)buf;
612 ret = i2c_transfer(adap, &msg, 1);
614 /* If everything went ok (i.e. 1 msg transmitted), return #bytes
615 transmitted, else error code. */
616 return (ret == 1) ? count : ret;
619 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
621 struct i2c_adapter *adap=client->adapter;
625 msg.addr = client->addr;
626 msg.flags = client->flags & I2C_M_TEN;
627 msg.flags |= I2C_M_RD;
631 ret = i2c_transfer(adap, &msg, 1);
633 /* If everything went ok (i.e. 1 msg transmitted), return #bytes
634 transmitted, else error code. */
635 return (ret == 1) ? count : ret;
639 int i2c_control(struct i2c_client *client,
640 unsigned int cmd, unsigned long arg)
643 struct i2c_adapter *adap = client->adapter;
645 dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
654 if (adap->algo->algo_control!=NULL)
655 ret = adap->algo->algo_control(adap,cmd,arg);
660 /* ----------------------------------------------------
661 * the i2c address scanning function
662 * Will not work for 10-bit addresses!
663 * ----------------------------------------------------
665 /* Return: kind (>= 0) if force found, -1 if not found */
666 static inline int i2c_probe_forces(struct i2c_adapter *adapter, int addr,
667 unsigned short **forces)
670 int j, adap_id = i2c_adapter_id(adapter);
672 for (kind = 0; forces[kind]; kind++) {
673 for (j = 0; forces[kind][j] != I2C_CLIENT_END; j += 2) {
674 if ((forces[kind][j] == adap_id ||
675 forces[kind][j] == ANY_I2C_BUS)
676 && forces[kind][j + 1] == addr) {
677 dev_dbg(&adapter->dev, "found force parameter, "
678 "addr 0x%02x, kind %u\n", addr, kind);
687 int i2c_probe(struct i2c_adapter *adapter,
688 struct i2c_client_address_data *address_data,
689 int (*found_proc) (struct i2c_adapter *, int, int))
691 int addr,i,found,err;
692 int adap_id = i2c_adapter_id(adapter);
694 /* Forget it if we can't probe using SMBUS_QUICK */
695 if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
698 for (addr = 0x00; addr <= 0x7f; addr++) {
700 /* Skip if already in use */
701 if (i2c_check_addr(adapter,addr))
704 /* If it is in one of the force entries, we don't do any detection
708 if (address_data->forces) {
709 int kind = i2c_probe_forces(adapter, addr,
710 address_data->forces);
711 if (kind >= 0) { /* force found */
712 if ((err = found_proc(adapter, addr, kind)))
718 /* If this address is in one of the ignores, we can forget about
721 !found && (address_data->ignore[i] != I2C_CLIENT_END);
723 if (((adap_id == address_data->ignore[i]) ||
724 ((address_data->ignore[i] == ANY_I2C_BUS))) &&
725 (addr == address_data->ignore[i+1])) {
726 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
727 "addr %04x\n", adap_id ,addr);
734 /* Now, we will do a detection, but only if it is in the normal or
737 !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
739 if (addr == address_data->normal_i2c[i]) {
741 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
742 "addr %02x\n", adap_id, addr);
747 !found && (address_data->probe[i] != I2C_CLIENT_END);
749 if (((adap_id == address_data->probe[i]) ||
750 ((address_data->probe[i] == ANY_I2C_BUS))) &&
751 (addr == address_data->probe[i+1])) {
753 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
754 "addr %04x\n", adap_id,addr);
760 /* OK, so we really should examine this address. First check
761 whether there is some client here at all! */
762 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
763 if ((err = found_proc(adapter,addr,-1)))
769 struct i2c_adapter* i2c_get_adapter(int id)
771 struct i2c_adapter *adapter;
774 adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
775 if (adapter && !try_module_get(adapter->owner))
782 void i2c_put_adapter(struct i2c_adapter *adap)
784 module_put(adap->owner);
787 /* The SMBus parts */
789 #define POLY (0x1070U << 3)
795 for(i = 0; i < 8; i++) {
800 return (u8)(data >> 8);
803 /* CRC over count bytes in the first array plus the bytes in the rest
804 array if it is non-null. rest[0] is the (length of rest) - 1
806 static u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
810 for(i = 0; i < count; i++)
811 crc = crc8((crc ^ first[i]) << 8);
813 for(i = 0; i <= rest[0]; i++)
814 crc = crc8((crc ^ rest[i]) << 8);
818 static u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
820 return i2c_smbus_partial_pec(0, count, first, rest);
823 /* Returns new "size" (transaction type)
824 Note that we convert byte to byte_data and byte_data to word_data
825 rather than invent new xxx_PEC transactions. */
826 static int i2c_smbus_add_pec(u16 addr, u8 command, int size,
827 union i2c_smbus_data *data)
835 data->byte = i2c_smbus_pec(2, buf, NULL);
836 size = I2C_SMBUS_BYTE_DATA;
838 case I2C_SMBUS_BYTE_DATA:
840 data->word = buf[2] ||
841 (i2c_smbus_pec(3, buf, NULL) << 8);
842 size = I2C_SMBUS_WORD_DATA;
844 case I2C_SMBUS_WORD_DATA:
847 case I2C_SMBUS_BLOCK_DATA:
848 data->block[data->block[0] + 1] =
849 i2c_smbus_pec(2, buf, data->block);
850 size = I2C_SMBUS_BLOCK_DATA_PEC;
856 static int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
857 union i2c_smbus_data *data)
859 u8 buf[3], rpec, cpec;
863 case I2C_SMBUS_BYTE_DATA:
864 buf[0] = (addr << 1) | 1;
865 cpec = i2c_smbus_pec(2, buf, NULL);
868 case I2C_SMBUS_WORD_DATA:
869 buf[0] = (addr << 1) | 1;
870 buf[2] = data->word & 0xff;
871 cpec = i2c_smbus_pec(3, buf, NULL);
872 rpec = data->word >> 8;
874 case I2C_SMBUS_WORD_DATA_PEC:
878 case I2C_SMBUS_PROC_CALL_PEC:
882 case I2C_SMBUS_BLOCK_DATA_PEC:
883 buf[0] = (addr << 1);
884 buf[2] = (addr << 1) | 1;
885 cpec = i2c_smbus_pec(3, buf, data->block);
886 rpec = data->block[data->block[0] + 1];
888 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
889 buf[0] = (addr << 1) | 1;
890 rpec = i2c_smbus_partial_pec(partial, 1,
892 cpec = data->block[data->block[0] + 1];
899 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
906 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
908 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
909 value,0,I2C_SMBUS_QUICK,NULL);
912 s32 i2c_smbus_read_byte(struct i2c_client *client)
914 union i2c_smbus_data data;
915 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
916 I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
919 return 0x0FF & data.byte;
922 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
924 union i2c_smbus_data data; /* only for PEC */
925 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
926 I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
929 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
931 union i2c_smbus_data data;
932 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
933 I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
936 return 0x0FF & data.byte;
939 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
941 union i2c_smbus_data data;
943 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
944 I2C_SMBUS_WRITE,command,
945 I2C_SMBUS_BYTE_DATA,&data);
948 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
950 union i2c_smbus_data data;
951 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
952 I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
955 return 0x0FFFF & data.word;
958 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
960 union i2c_smbus_data data;
962 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
963 I2C_SMBUS_WRITE,command,
964 I2C_SMBUS_WORD_DATA,&data);
967 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
968 u8 length, u8 *values)
970 union i2c_smbus_data data;
972 if (length > I2C_SMBUS_BLOCK_MAX)
973 length = I2C_SMBUS_BLOCK_MAX;
974 for (i = 1; i <= length; i++)
975 data.block[i] = values[i-1];
976 data.block[0] = length;
977 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
978 I2C_SMBUS_WRITE,command,
979 I2C_SMBUS_BLOCK_DATA,&data);
982 /* Returns the number of read bytes */
983 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
985 union i2c_smbus_data data;
987 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
988 I2C_SMBUS_READ,command,
989 I2C_SMBUS_I2C_BLOCK_DATA,&data))
992 for (i = 1; i <= data.block[0]; i++)
993 values[i-1] = data.block[i];
994 return data.block[0];
998 /* Simulate a SMBus command using the i2c protocol
999 No checking of parameters is done! */
1000 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1001 unsigned short flags,
1002 char read_write, u8 command, int size,
1003 union i2c_smbus_data * data)
1005 /* So we need to generate a series of msgs. In the case of writing, we
1006 need to use only one message; when reading, we need two. We initialize
1007 most things with sane defaults, to keep the code below somewhat
1009 unsigned char msgbuf0[34];
1010 unsigned char msgbuf1[34];
1011 int num = read_write == I2C_SMBUS_READ?2:1;
1012 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1013 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1017 msgbuf0[0] = command;
1019 case I2C_SMBUS_QUICK:
1021 /* Special case: The read/write field is used as data */
1022 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1025 case I2C_SMBUS_BYTE:
1026 if (read_write == I2C_SMBUS_READ) {
1027 /* Special case: only a read! */
1028 msg[0].flags = I2C_M_RD | flags;
1032 case I2C_SMBUS_BYTE_DATA:
1033 if (read_write == I2C_SMBUS_READ)
1037 msgbuf0[1] = data->byte;
1040 case I2C_SMBUS_WORD_DATA:
1041 if (read_write == I2C_SMBUS_READ)
1045 msgbuf0[1] = data->word & 0xff;
1046 msgbuf0[2] = (data->word >> 8) & 0xff;
1049 case I2C_SMBUS_PROC_CALL:
1050 num = 2; /* Special case */
1051 read_write = I2C_SMBUS_READ;
1054 msgbuf0[1] = data->word & 0xff;
1055 msgbuf0[2] = (data->word >> 8) & 0xff;
1057 case I2C_SMBUS_BLOCK_DATA:
1058 case I2C_SMBUS_BLOCK_DATA_PEC:
1059 if (read_write == I2C_SMBUS_READ) {
1060 dev_err(&adapter->dev, "Block read not supported "
1061 "under I2C emulation!\n");
1064 msg[0].len = data->block[0] + 2;
1065 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1066 dev_err(&adapter->dev, "smbus_access called with "
1067 "invalid block write size (%d)\n",
1071 if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1073 for (i = 1; i <= msg[0].len; i++)
1074 msgbuf0[i] = data->block[i-1];
1077 case I2C_SMBUS_BLOCK_PROC_CALL:
1078 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1079 dev_dbg(&adapter->dev, "Block process call not supported "
1080 "under I2C emulation!\n");
1082 case I2C_SMBUS_I2C_BLOCK_DATA:
1083 if (read_write == I2C_SMBUS_READ) {
1084 msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1086 msg[0].len = data->block[0] + 1;
1087 if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1088 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1089 "invalid block write size (%d)\n",
1093 for (i = 1; i <= data->block[0]; i++)
1094 msgbuf0[i] = data->block[i];
1098 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1103 if (i2c_transfer(adapter, msg, num) < 0)
1106 if (read_write == I2C_SMBUS_READ)
1108 case I2C_SMBUS_BYTE:
1109 data->byte = msgbuf0[0];
1111 case I2C_SMBUS_BYTE_DATA:
1112 data->byte = msgbuf1[0];
1114 case I2C_SMBUS_WORD_DATA:
1115 case I2C_SMBUS_PROC_CALL:
1116 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1118 case I2C_SMBUS_I2C_BLOCK_DATA:
1119 /* fixed at 32 for now */
1120 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1121 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1122 data->block[i+1] = msgbuf1[i];
1129 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1130 char read_write, u8 command, int size,
1131 union i2c_smbus_data * data)
1137 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1138 if((flags & I2C_CLIENT_PEC) &&
1139 !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1141 if(read_write == I2C_SMBUS_READ &&
1142 size == I2C_SMBUS_BLOCK_DATA)
1143 size = I2C_SMBUS_BLOCK_DATA_PEC;
1144 else if(size == I2C_SMBUS_PROC_CALL)
1145 size = I2C_SMBUS_PROC_CALL_PEC;
1146 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1147 i2c_smbus_add_pec(addr, command,
1148 I2C_SMBUS_BLOCK_DATA, data);
1149 partial = data->block[data->block[0] + 1];
1150 size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1151 } else if(read_write == I2C_SMBUS_WRITE &&
1152 size != I2C_SMBUS_QUICK &&
1153 size != I2C_SMBUS_I2C_BLOCK_DATA)
1154 size = i2c_smbus_add_pec(addr, command, size, data);
1157 if (adapter->algo->smbus_xfer) {
1158 down(&adapter->bus_lock);
1159 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1161 up(&adapter->bus_lock);
1163 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1166 if(res >= 0 && swpec &&
1167 size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1168 (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1169 size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1170 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1177 /* Next four are needed by i2c-isa */
1178 EXPORT_SYMBOL_GPL(i2c_adapter_dev_release);
1179 EXPORT_SYMBOL_GPL(i2c_adapter_driver);
1180 EXPORT_SYMBOL_GPL(i2c_adapter_class);
1181 EXPORT_SYMBOL_GPL(i2c_bus_type);
1183 EXPORT_SYMBOL(i2c_add_adapter);
1184 EXPORT_SYMBOL(i2c_del_adapter);
1185 EXPORT_SYMBOL(i2c_add_driver);
1186 EXPORT_SYMBOL(i2c_del_driver);
1187 EXPORT_SYMBOL(i2c_attach_client);
1188 EXPORT_SYMBOL(i2c_detach_client);
1189 EXPORT_SYMBOL(i2c_use_client);
1190 EXPORT_SYMBOL(i2c_release_client);
1191 EXPORT_SYMBOL(i2c_clients_command);
1192 EXPORT_SYMBOL(i2c_check_addr);
1194 EXPORT_SYMBOL(i2c_master_send);
1195 EXPORT_SYMBOL(i2c_master_recv);
1196 EXPORT_SYMBOL(i2c_control);
1197 EXPORT_SYMBOL(i2c_transfer);
1198 EXPORT_SYMBOL(i2c_get_adapter);
1199 EXPORT_SYMBOL(i2c_put_adapter);
1200 EXPORT_SYMBOL(i2c_probe);
1202 EXPORT_SYMBOL(i2c_smbus_xfer);
1203 EXPORT_SYMBOL(i2c_smbus_write_quick);
1204 EXPORT_SYMBOL(i2c_smbus_read_byte);
1205 EXPORT_SYMBOL(i2c_smbus_write_byte);
1206 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1207 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1208 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1209 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1210 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1211 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1213 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1214 MODULE_DESCRIPTION("I2C-Bus main module");
1215 MODULE_LICENSE("GPL");