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/config.h>
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/seq_file.h>
33 #include <asm/uaccess.h>
36 static LIST_HEAD(adapters);
37 static LIST_HEAD(drivers);
38 static DECLARE_MUTEX(core_lists);
39 static DEFINE_IDR(i2c_adapter_idr);
41 int i2c_device_probe(struct device *dev)
46 int i2c_device_remove(struct device *dev)
51 static void i2c_adapter_dev_release(struct device *dev)
53 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
54 complete(&adap->dev_released);
57 static struct device_driver i2c_adapter_driver = {
58 .name = "i2c_adapter",
60 .probe = i2c_device_probe,
61 .remove = i2c_device_remove,
64 static void i2c_adapter_class_dev_release(struct class_device *dev)
66 struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
67 complete(&adap->class_dev_released);
70 static struct class i2c_adapter_class = {
71 .name = "i2c-adapter",
72 .release = &i2c_adapter_class_dev_release,
75 static ssize_t show_adapter_name(struct device *dev, char *buf)
77 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
78 return sprintf(buf, "%s\n", adap->name);
80 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
83 static void i2c_client_release(struct device *dev)
85 struct i2c_client *client = to_i2c_client(dev);
86 complete(&client->released);
89 static ssize_t show_client_name(struct device *dev, char *buf)
91 struct i2c_client *client = to_i2c_client(dev);
92 return sprintf(buf, "%s\n", client->name);
96 * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
97 * different type of a device. So beware if the DEVICE_ATTR() macro ever
98 * changes, this definition will also have to change.
100 static struct device_attribute dev_attr_client_name = {
101 .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
102 .show = &show_client_name,
106 /* ---------------------------------------------------
107 * registering functions
108 * ---------------------------------------------------
112 * i2c_add_adapter is called from within the algorithm layer,
113 * when a new hw adapter registers. A new device is register to be
114 * available for clients.
116 int i2c_add_adapter(struct i2c_adapter *adap)
119 struct list_head *item;
120 struct i2c_driver *driver;
124 if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
129 res = idr_get_new(&i2c_adapter_idr, NULL, &id);
136 adap->nr = id & MAX_ID_MASK;
137 init_MUTEX(&adap->bus_lock);
138 init_MUTEX(&adap->clist_lock);
139 list_add_tail(&adap->list,&adapters);
140 INIT_LIST_HEAD(&adap->clients);
142 /* Add the adapter to the driver core.
143 * If the parent pointer is not set up,
144 * we add this adapter to the host bus.
146 if (adap->dev.parent == NULL)
147 adap->dev.parent = &platform_bus;
148 sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
149 adap->dev.driver = &i2c_adapter_driver;
150 adap->dev.release = &i2c_adapter_dev_release;
151 device_register(&adap->dev);
152 device_create_file(&adap->dev, &dev_attr_name);
154 /* Add this adapter to the i2c_adapter class */
155 memset(&adap->class_dev, 0x00, sizeof(struct class_device));
156 adap->class_dev.dev = &adap->dev;
157 adap->class_dev.class = &i2c_adapter_class;
158 strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
159 class_device_register(&adap->class_dev);
161 /* inform drivers of new adapters */
162 list_for_each(item,&drivers) {
163 driver = list_entry(item, struct i2c_driver, list);
164 if (driver->flags & I2C_DF_NOTIFY)
165 /* We ignore the return code; if it fails, too bad */
166 driver->attach_adapter(adap);
169 dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
177 int i2c_del_adapter(struct i2c_adapter *adap)
179 struct list_head *item, *_n;
180 struct i2c_driver *driver;
181 struct i2c_client *client;
186 list_for_each(item,&drivers) {
187 driver = list_entry(item, struct i2c_driver, list);
188 if (driver->detach_adapter)
189 if ((res = driver->detach_adapter(adap))) {
190 dev_warn(&adap->dev, "can't detach adapter "
191 "while detaching driver %s: driver not "
192 "detached!", driver->name);
197 /* detach any active clients. This must be done first, because
198 * it can fail; in which case we give upp. */
199 list_for_each_safe(item, _n, &adap->clients) {
200 client = list_entry(item, struct i2c_client, list);
202 /* detaching devices is unconditional of the set notify
203 * flag, as _all_ clients that reside on the adapter
204 * must be deleted, as this would cause invalid states.
206 if ((res=client->driver->detach_client(client))) {
207 dev_err(&adap->dev, "adapter not "
208 "unregistered, because client at "
209 "address %02x can't be detached. ",
215 /* clean up the sysfs representation */
216 init_completion(&adap->dev_released);
217 init_completion(&adap->class_dev_released);
218 class_device_unregister(&adap->class_dev);
219 device_remove_file(&adap->dev, &dev_attr_name);
220 device_unregister(&adap->dev);
221 list_del(&adap->list);
223 /* wait for sysfs to drop all references */
224 wait_for_completion(&adap->dev_released);
225 wait_for_completion(&adap->class_dev_released);
227 /* free dynamically allocated bus id */
228 idr_remove(&i2c_adapter_idr, adap->nr);
230 dev_dbg(&adap->dev, "adapter unregistered\n");
239 * What follows is the "upwards" interface: commands for talking to clients,
240 * which implement the functions to access the physical information of the
244 int i2c_add_driver(struct i2c_driver *driver)
246 struct list_head *item;
247 struct i2c_adapter *adapter;
252 /* add the driver to the list of i2c drivers in the driver core */
253 driver->driver.name = driver->name;
254 driver->driver.bus = &i2c_bus_type;
255 driver->driver.probe = i2c_device_probe;
256 driver->driver.remove = i2c_device_remove;
258 res = driver_register(&driver->driver);
262 list_add_tail(&driver->list,&drivers);
263 pr_debug("i2c-core: driver %s registered.\n", driver->name);
265 /* now look for instances of driver on our adapters */
266 if (driver->flags & I2C_DF_NOTIFY) {
267 list_for_each(item,&adapters) {
268 adapter = list_entry(item, struct i2c_adapter, list);
269 driver->attach_adapter(adapter);
278 int i2c_del_driver(struct i2c_driver *driver)
280 struct list_head *item1, *item2, *_n;
281 struct i2c_client *client;
282 struct i2c_adapter *adap;
288 /* Have a look at each adapter, if clients of this driver are still
289 * attached. If so, detach them to be able to kill the driver
292 pr_debug("i2c-core: unregister_driver - looking for clients.\n");
293 /* removing clients does not depend on the notify flag, else
294 * invalid operation might (will!) result, when using stale client
297 list_for_each(item1,&adapters) {
298 adap = list_entry(item1, struct i2c_adapter, list);
299 dev_dbg(&adap->dev, "examining adapter\n");
300 if (driver->detach_adapter) {
301 if ((res = driver->detach_adapter(adap))) {
302 dev_warn(&adap->dev, "while unregistering "
303 "dummy driver %s, adapter could "
304 "not be detached properly; driver "
305 "not unloaded!",driver->name);
309 list_for_each_safe(item2, _n, &adap->clients) {
310 client = list_entry(item2, struct i2c_client, list);
311 if (client->driver != driver)
313 pr_debug("i2c-core.o: detaching client %s:\n", client->name);
314 if ((res = driver->detach_client(client))) {
315 dev_err(&adap->dev, "while "
316 "unregistering driver "
317 "`%s', the client at "
320 "be detached; driver "
330 driver_unregister(&driver->driver);
331 list_del(&driver->list);
332 pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
339 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
341 struct list_head *item;
342 struct i2c_client *client;
344 list_for_each(item,&adapter->clients) {
345 client = list_entry(item, struct i2c_client, list);
346 if (client->addr == addr)
352 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
356 down(&adapter->clist_lock);
357 rval = __i2c_check_addr(adapter, addr);
358 up(&adapter->clist_lock);
363 int i2c_attach_client(struct i2c_client *client)
365 struct i2c_adapter *adapter = client->adapter;
367 down(&adapter->clist_lock);
368 if (__i2c_check_addr(client->adapter, client->addr)) {
369 up(&adapter->clist_lock);
372 list_add_tail(&client->list,&adapter->clients);
373 up(&adapter->clist_lock);
375 if (adapter->client_register) {
376 if (adapter->client_register(client)) {
377 dev_warn(&adapter->dev, "warning: client_register "
378 "seems to have failed for client %02x\n",
383 dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
386 if (client->flags & I2C_CLIENT_ALLOW_USE)
387 client->usage_count = 0;
389 client->dev.parent = &client->adapter->dev;
390 client->dev.driver = &client->driver->driver;
391 client->dev.bus = &i2c_bus_type;
392 client->dev.release = &i2c_client_release;
394 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
395 "%d-%04x", i2c_adapter_id(adapter), client->addr);
396 pr_debug("registering %s\n", client->dev.bus_id);
397 device_register(&client->dev);
398 device_create_file(&client->dev, &dev_attr_client_name);
404 int i2c_detach_client(struct i2c_client *client)
406 struct i2c_adapter *adapter = client->adapter;
409 if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
412 if (adapter->client_unregister) {
413 res = adapter->client_unregister(client);
415 dev_err(&client->dev,
416 "client_unregister [%s] failed, "
417 "client not detached", client->name);
422 down(&adapter->clist_lock);
423 list_del(&client->list);
424 init_completion(&client->released);
425 device_remove_file(&client->dev, &dev_attr_client_name);
426 device_unregister(&client->dev);
427 up(&adapter->clist_lock);
428 wait_for_completion(&client->released);
434 static int i2c_inc_use_client(struct i2c_client *client)
437 if (!try_module_get(client->driver->owner))
439 if (!try_module_get(client->adapter->owner)) {
440 module_put(client->driver->owner);
447 static void i2c_dec_use_client(struct i2c_client *client)
449 module_put(client->driver->owner);
450 module_put(client->adapter->owner);
453 int i2c_use_client(struct i2c_client *client)
457 ret = i2c_inc_use_client(client);
461 if (client->flags & I2C_CLIENT_ALLOW_USE) {
462 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
463 client->usage_count++;
464 else if (client->usage_count > 0)
467 client->usage_count++;
472 i2c_dec_use_client(client);
476 int i2c_release_client(struct i2c_client *client)
478 if(client->flags & I2C_CLIENT_ALLOW_USE) {
479 if(client->usage_count>0)
480 client->usage_count--;
482 pr_debug("i2c-core: %s used one too many times\n",
488 i2c_dec_use_client(client);
493 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
495 struct list_head *item;
496 struct i2c_client *client;
498 down(&adap->clist_lock);
499 list_for_each(item,&adap->clients) {
500 client = list_entry(item, struct i2c_client, list);
501 if (!try_module_get(client->driver->owner))
503 if (NULL != client->driver->command) {
504 up(&adap->clist_lock);
505 client->driver->command(client,cmd,arg);
506 down(&adap->clist_lock);
508 module_put(client->driver->owner);
510 up(&adap->clist_lock);
514 /* match always succeeds, as we want the probe() to tell if we really accept this match */
515 static int i2c_device_match(struct device *dev, struct device_driver *drv)
520 struct bus_type i2c_bus_type = {
522 .match = i2c_device_match,
525 static int __init i2c_init(void)
529 retval = bus_register(&i2c_bus_type);
532 retval = driver_register(&i2c_adapter_driver);
535 return class_register(&i2c_adapter_class);
538 static void __exit i2c_exit(void)
540 class_unregister(&i2c_adapter_class);
541 driver_unregister(&i2c_adapter_driver);
542 bus_unregister(&i2c_bus_type);
545 subsys_initcall(i2c_init);
546 module_exit(i2c_exit);
548 /* ----------------------------------------------------
549 * the functional interface to the i2c busses.
550 * ----------------------------------------------------
553 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg msgs[],int num)
557 if (adap->algo->master_xfer) {
558 dev_dbg(&adap->dev, "master_xfer: with %d msgs.\n", num);
560 down(&adap->bus_lock);
561 ret = adap->algo->master_xfer(adap,msgs,num);
566 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
571 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
574 struct i2c_adapter *adap=client->adapter;
577 if (client->adapter->algo->master_xfer) {
578 msg.addr = client->addr;
579 msg.flags = client->flags & I2C_M_TEN;
581 msg.buf = (char *)buf;
583 dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
586 down(&adap->bus_lock);
587 ret = adap->algo->master_xfer(adap,&msg,1);
590 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
591 * transmitted, else error code.
593 return (ret == 1 )? count : ret;
595 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
600 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
602 struct i2c_adapter *adap=client->adapter;
605 if (client->adapter->algo->master_xfer) {
606 msg.addr = client->addr;
607 msg.flags = client->flags & I2C_M_TEN;
608 msg.flags |= I2C_M_RD;
612 dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
615 down(&adap->bus_lock);
616 ret = adap->algo->master_xfer(adap,&msg,1);
619 dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
620 ret, count, client->addr);
622 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
623 * transmitted, else error code.
625 return (ret == 1 )? count : ret;
627 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
633 int i2c_control(struct i2c_client *client,
634 unsigned int cmd, unsigned long arg)
637 struct i2c_adapter *adap = client->adapter;
639 dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
648 if (adap->algo->algo_control!=NULL)
649 ret = adap->algo->algo_control(adap,cmd,arg);
654 /* ----------------------------------------------------
655 * the i2c address scanning function
656 * Will not work for 10-bit addresses!
657 * ----------------------------------------------------
659 int i2c_probe(struct i2c_adapter *adapter,
660 struct i2c_client_address_data *address_data,
661 int (*found_proc) (struct i2c_adapter *, int, int))
663 int addr,i,found,err;
664 int adap_id = i2c_adapter_id(adapter);
666 /* Forget it if we can't probe using SMBUS_QUICK */
667 if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
670 for (addr = 0x00; addr <= 0x7f; addr++) {
672 /* Skip if already in use */
673 if (i2c_check_addr(adapter,addr))
676 /* If it is in one of the force entries, we don't do any detection
680 for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 3) {
681 if (((adap_id == address_data->force[i]) ||
682 (address_data->force[i] == ANY_I2C_BUS)) &&
683 (addr == address_data->force[i+1])) {
684 dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
686 if ((err = found_proc(adapter,addr,0)))
694 /* If this address is in one of the ignores, we can forget about
697 !found && (address_data->ignore[i] != I2C_CLIENT_END);
699 if (((adap_id == address_data->ignore[i]) ||
700 ((address_data->ignore[i] == ANY_I2C_BUS))) &&
701 (addr == address_data->ignore[i+1])) {
702 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
703 "addr %04x\n", adap_id ,addr);
708 !found && (address_data->ignore_range[i] != I2C_CLIENT_END);
710 if (((adap_id == address_data->ignore_range[i]) ||
711 ((address_data->ignore_range[i]==ANY_I2C_BUS))) &&
712 (addr >= address_data->ignore_range[i+1]) &&
713 (addr <= address_data->ignore_range[i+2])) {
714 dev_dbg(&adapter->dev, "found ignore_range parameter for adapter %d, "
715 "addr %04x\n", adap_id,addr);
722 /* Now, we will do a detection, but only if it is in the normal or
725 !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
727 if (addr == address_data->normal_i2c[i]) {
729 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
730 "addr %02x", adap_id,addr);
735 !found && (address_data->normal_i2c_range[i] != I2C_CLIENT_END);
737 if ((addr >= address_data->normal_i2c_range[i]) &&
738 (addr <= address_data->normal_i2c_range[i+1])) {
740 dev_dbg(&adapter->dev, "found normal i2c_range entry for adapter %d, "
741 "addr %04x\n", adap_id,addr);
746 !found && (address_data->probe[i] != I2C_CLIENT_END);
748 if (((adap_id == address_data->probe[i]) ||
749 ((address_data->probe[i] == ANY_I2C_BUS))) &&
750 (addr == address_data->probe[i+1])) {
752 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
753 "addr %04x\n", adap_id,addr);
757 !found && (address_data->probe_range[i] != I2C_CLIENT_END);
759 if (((adap_id == address_data->probe_range[i]) ||
760 (address_data->probe_range[i] == ANY_I2C_BUS)) &&
761 (addr >= address_data->probe_range[i+1]) &&
762 (addr <= address_data->probe_range[i+2])) {
764 dev_dbg(&adapter->dev, "found probe_range parameter for adapter %d, "
765 "addr %04x\n", adap_id,addr);
771 /* OK, so we really should examine this address. First check
772 whether there is some client here at all! */
773 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
774 if ((err = found_proc(adapter,addr,-1)))
781 * return id number for a specific adapter
783 int i2c_adapter_id(struct i2c_adapter *adap)
788 struct i2c_adapter* i2c_get_adapter(int id)
790 struct list_head *item;
791 struct i2c_adapter *adapter;
794 list_for_each(item,&adapters) {
795 adapter = list_entry(item, struct i2c_adapter, list);
796 if (id == adapter->nr &&
797 try_module_get(adapter->owner)) {
806 void i2c_put_adapter(struct i2c_adapter *adap)
808 module_put(adap->owner);
811 /* The SMBus parts */
813 #define POLY (0x1070U << 3)
819 for(i = 0; i < 8; i++) {
824 return (u8)(data >> 8);
827 /* CRC over count bytes in the first array plus the bytes in the rest
828 array if it is non-null. rest[0] is the (length of rest) - 1
830 u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
834 for(i = 0; i < count; i++)
835 crc = crc8((crc ^ first[i]) << 8);
837 for(i = 0; i <= rest[0]; i++)
838 crc = crc8((crc ^ rest[i]) << 8);
842 u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
844 return i2c_smbus_partial_pec(0, count, first, rest);
847 /* Returns new "size" (transaction type)
848 Note that we convert byte to byte_data and byte_data to word_data
849 rather than invent new xxx_PEC transactions. */
850 int i2c_smbus_add_pec(u16 addr, u8 command, int size,
851 union i2c_smbus_data *data)
859 data->byte = i2c_smbus_pec(2, buf, NULL);
860 size = I2C_SMBUS_BYTE_DATA;
862 case I2C_SMBUS_BYTE_DATA:
864 data->word = buf[2] ||
865 (i2c_smbus_pec(3, buf, NULL) << 8);
866 size = I2C_SMBUS_WORD_DATA;
868 case I2C_SMBUS_WORD_DATA:
871 case I2C_SMBUS_BLOCK_DATA:
872 data->block[data->block[0] + 1] =
873 i2c_smbus_pec(2, buf, data->block);
874 size = I2C_SMBUS_BLOCK_DATA_PEC;
880 int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
881 union i2c_smbus_data *data)
883 u8 buf[3], rpec, cpec;
887 case I2C_SMBUS_BYTE_DATA:
888 buf[0] = (addr << 1) | 1;
889 cpec = i2c_smbus_pec(2, buf, NULL);
892 case I2C_SMBUS_WORD_DATA:
893 buf[0] = (addr << 1) | 1;
894 buf[2] = data->word & 0xff;
895 cpec = i2c_smbus_pec(3, buf, NULL);
896 rpec = data->word >> 8;
898 case I2C_SMBUS_WORD_DATA_PEC:
902 case I2C_SMBUS_PROC_CALL_PEC:
906 case I2C_SMBUS_BLOCK_DATA_PEC:
907 buf[0] = (addr << 1);
908 buf[2] = (addr << 1) | 1;
909 cpec = i2c_smbus_pec(3, buf, data->block);
910 rpec = data->block[data->block[0] + 1];
912 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
913 buf[0] = (addr << 1) | 1;
914 rpec = i2c_smbus_partial_pec(partial, 1,
916 cpec = data->block[data->block[0] + 1];
923 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
930 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
932 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
933 value,0,I2C_SMBUS_QUICK,NULL);
936 s32 i2c_smbus_read_byte(struct i2c_client *client)
938 union i2c_smbus_data data;
939 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
940 I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
943 return 0x0FF & data.byte;
946 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
948 union i2c_smbus_data data; /* only for PEC */
949 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
950 I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
953 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
955 union i2c_smbus_data data;
956 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
957 I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
960 return 0x0FF & data.byte;
963 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
965 union i2c_smbus_data data;
967 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
968 I2C_SMBUS_WRITE,command,
969 I2C_SMBUS_BYTE_DATA,&data);
972 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
974 union i2c_smbus_data data;
975 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
976 I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
979 return 0x0FFFF & data.word;
982 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
984 union i2c_smbus_data data;
986 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
987 I2C_SMBUS_WRITE,command,
988 I2C_SMBUS_WORD_DATA,&data);
991 s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
993 union i2c_smbus_data data;
995 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
996 I2C_SMBUS_WRITE,command,
997 I2C_SMBUS_PROC_CALL, &data))
1000 return 0x0FFFF & data.word;
1003 /* Returns the number of read bytes */
1004 s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, u8 *values)
1006 union i2c_smbus_data data;
1008 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1009 I2C_SMBUS_READ,command,
1010 I2C_SMBUS_BLOCK_DATA,&data))
1013 for (i = 1; i <= data.block[0]; i++)
1014 values[i-1] = data.block[i];
1015 return data.block[0];
1019 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values)
1021 union i2c_smbus_data data;
1023 if (length > I2C_SMBUS_BLOCK_MAX)
1024 length = I2C_SMBUS_BLOCK_MAX;
1025 for (i = 1; i <= length; i++)
1026 data.block[i] = values[i-1];
1027 data.block[0] = length;
1028 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1029 I2C_SMBUS_WRITE,command,
1030 I2C_SMBUS_BLOCK_DATA,&data);
1033 /* Returns the number of read bytes */
1034 s32 i2c_smbus_block_process_call(struct i2c_client *client, u8 command, u8 length, u8 *values)
1036 union i2c_smbus_data data;
1038 if (length > I2C_SMBUS_BLOCK_MAX - 1)
1040 data.block[0] = length;
1041 for (i = 1; i <= length; i++)
1042 data.block[i] = values[i-1];
1043 if(i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1044 I2C_SMBUS_WRITE, command,
1045 I2C_SMBUS_BLOCK_PROC_CALL, &data))
1047 for (i = 1; i <= data.block[0]; i++)
1048 values[i-1] = data.block[i];
1049 return data.block[0];
1052 /* Returns the number of read bytes */
1053 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1055 union i2c_smbus_data data;
1057 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1058 I2C_SMBUS_READ,command,
1059 I2C_SMBUS_I2C_BLOCK_DATA,&data))
1062 for (i = 1; i <= data.block[0]; i++)
1063 values[i-1] = data.block[i];
1064 return data.block[0];
1068 s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values)
1070 union i2c_smbus_data data;
1072 if (length > I2C_SMBUS_I2C_BLOCK_MAX)
1073 length = I2C_SMBUS_I2C_BLOCK_MAX;
1074 for (i = 1; i <= length; i++)
1075 data.block[i] = values[i-1];
1076 data.block[0] = length;
1077 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1078 I2C_SMBUS_WRITE,command,
1079 I2C_SMBUS_I2C_BLOCK_DATA,&data);
1082 /* Simulate a SMBus command using the i2c protocol
1083 No checking of parameters is done! */
1084 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1085 unsigned short flags,
1086 char read_write, u8 command, int size,
1087 union i2c_smbus_data * data)
1089 /* So we need to generate a series of msgs. In the case of writing, we
1090 need to use only one message; when reading, we need two. We initialize
1091 most things with sane defaults, to keep the code below somewhat
1093 unsigned char msgbuf0[34];
1094 unsigned char msgbuf1[34];
1095 int num = read_write == I2C_SMBUS_READ?2:1;
1096 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1097 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1101 msgbuf0[0] = command;
1103 case I2C_SMBUS_QUICK:
1105 /* Special case: The read/write field is used as data */
1106 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1109 case I2C_SMBUS_BYTE:
1110 if (read_write == I2C_SMBUS_READ) {
1111 /* Special case: only a read! */
1112 msg[0].flags = I2C_M_RD | flags;
1116 case I2C_SMBUS_BYTE_DATA:
1117 if (read_write == I2C_SMBUS_READ)
1121 msgbuf0[1] = data->byte;
1124 case I2C_SMBUS_WORD_DATA:
1125 if (read_write == I2C_SMBUS_READ)
1129 msgbuf0[1] = data->word & 0xff;
1130 msgbuf0[2] = (data->word >> 8) & 0xff;
1133 case I2C_SMBUS_PROC_CALL:
1134 num = 2; /* Special case */
1135 read_write = I2C_SMBUS_READ;
1138 msgbuf0[1] = data->word & 0xff;
1139 msgbuf0[2] = (data->word >> 8) & 0xff;
1141 case I2C_SMBUS_BLOCK_DATA:
1142 case I2C_SMBUS_BLOCK_DATA_PEC:
1143 if (read_write == I2C_SMBUS_READ) {
1144 dev_err(&adapter->dev, "Block read not supported "
1145 "under I2C emulation!\n");
1148 msg[0].len = data->block[0] + 2;
1149 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1150 dev_err(&adapter->dev, "smbus_access called with "
1151 "invalid block write size (%d)\n",
1155 if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1157 for (i = 1; i <= msg[0].len; i++)
1158 msgbuf0[i] = data->block[i-1];
1161 case I2C_SMBUS_BLOCK_PROC_CALL:
1162 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1163 dev_dbg(&adapter->dev, "Block process call not supported "
1164 "under I2C emulation!\n");
1166 case I2C_SMBUS_I2C_BLOCK_DATA:
1167 if (read_write == I2C_SMBUS_READ) {
1168 msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1170 msg[0].len = data->block[0] + 1;
1171 if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1172 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1173 "invalid block write size (%d)\n",
1177 for (i = 1; i <= data->block[0]; i++)
1178 msgbuf0[i] = data->block[i];
1182 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1187 if (i2c_transfer(adapter, msg, num) < 0)
1190 if (read_write == I2C_SMBUS_READ)
1192 case I2C_SMBUS_BYTE:
1193 data->byte = msgbuf0[0];
1195 case I2C_SMBUS_BYTE_DATA:
1196 data->byte = msgbuf1[0];
1198 case I2C_SMBUS_WORD_DATA:
1199 case I2C_SMBUS_PROC_CALL:
1200 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1202 case I2C_SMBUS_I2C_BLOCK_DATA:
1203 /* fixed at 32 for now */
1204 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1205 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1206 data->block[i+1] = msgbuf1[i];
1213 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1214 char read_write, u8 command, int size,
1215 union i2c_smbus_data * data)
1221 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1222 if((flags & I2C_CLIENT_PEC) &&
1223 !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1225 if(read_write == I2C_SMBUS_READ &&
1226 size == I2C_SMBUS_BLOCK_DATA)
1227 size = I2C_SMBUS_BLOCK_DATA_PEC;
1228 else if(size == I2C_SMBUS_PROC_CALL)
1229 size = I2C_SMBUS_PROC_CALL_PEC;
1230 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1231 i2c_smbus_add_pec(addr, command,
1232 I2C_SMBUS_BLOCK_DATA, data);
1233 partial = data->block[data->block[0] + 1];
1234 size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1235 } else if(read_write == I2C_SMBUS_WRITE &&
1236 size != I2C_SMBUS_QUICK &&
1237 size != I2C_SMBUS_I2C_BLOCK_DATA)
1238 size = i2c_smbus_add_pec(addr, command, size, data);
1241 if (adapter->algo->smbus_xfer) {
1242 down(&adapter->bus_lock);
1243 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1245 up(&adapter->bus_lock);
1247 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1250 if(res >= 0 && swpec &&
1251 size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1252 (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1253 size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1254 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1261 /* You should always define `functionality'; the 'else' is just for
1262 backward compatibility. */
1263 u32 i2c_get_functionality (struct i2c_adapter *adap)
1265 if (adap->algo->functionality)
1266 return adap->algo->functionality(adap);
1271 int i2c_check_functionality (struct i2c_adapter *adap, u32 func)
1273 u32 adap_func = i2c_get_functionality (adap);
1274 return (func & adap_func) == func;
1277 EXPORT_SYMBOL(i2c_add_adapter);
1278 EXPORT_SYMBOL(i2c_del_adapter);
1279 EXPORT_SYMBOL(i2c_add_driver);
1280 EXPORT_SYMBOL(i2c_del_driver);
1281 EXPORT_SYMBOL(i2c_attach_client);
1282 EXPORT_SYMBOL(i2c_detach_client);
1283 EXPORT_SYMBOL(i2c_use_client);
1284 EXPORT_SYMBOL(i2c_release_client);
1285 EXPORT_SYMBOL(i2c_clients_command);
1286 EXPORT_SYMBOL(i2c_check_addr);
1288 EXPORT_SYMBOL(i2c_master_send);
1289 EXPORT_SYMBOL(i2c_master_recv);
1290 EXPORT_SYMBOL(i2c_control);
1291 EXPORT_SYMBOL(i2c_transfer);
1292 EXPORT_SYMBOL(i2c_adapter_id);
1293 EXPORT_SYMBOL(i2c_get_adapter);
1294 EXPORT_SYMBOL(i2c_put_adapter);
1295 EXPORT_SYMBOL(i2c_probe);
1297 EXPORT_SYMBOL(i2c_smbus_xfer);
1298 EXPORT_SYMBOL(i2c_smbus_write_quick);
1299 EXPORT_SYMBOL(i2c_smbus_read_byte);
1300 EXPORT_SYMBOL(i2c_smbus_write_byte);
1301 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1302 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1303 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1304 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1305 EXPORT_SYMBOL(i2c_smbus_process_call);
1306 EXPORT_SYMBOL(i2c_smbus_read_block_data);
1307 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1308 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1309 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1311 EXPORT_SYMBOL(i2c_get_functionality);
1312 EXPORT_SYMBOL(i2c_check_functionality);
1314 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1315 MODULE_DESCRIPTION("I2C-Bus main module");
1316 MODULE_LICENSE("GPL");