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/seq_file.h>
32 #include <asm/uaccess.h>
35 static LIST_HEAD(adapters);
36 static LIST_HEAD(drivers);
37 static DECLARE_MUTEX(core_lists);
39 int i2c_device_probe(struct device *dev)
44 int i2c_device_remove(struct device *dev)
49 static void i2c_adapter_dev_release(struct device *dev)
51 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
52 complete(&adap->dev_released);
55 static struct device_driver i2c_adapter_driver = {
56 .name = "i2c_adapter",
58 .probe = i2c_device_probe,
59 .remove = i2c_device_remove,
62 static void i2c_adapter_class_dev_release(struct class_device *dev)
64 struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
65 complete(&adap->class_dev_released);
68 static struct class i2c_adapter_class = {
69 .name = "i2c-adapter",
70 .release = &i2c_adapter_class_dev_release,
73 static ssize_t show_adapter_name(struct device *dev, char *buf)
75 struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
76 return sprintf(buf, "%s\n", adap->name);
78 static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
81 static void i2c_client_release(struct device *dev)
83 struct i2c_client *client = to_i2c_client(dev);
84 complete(&client->released);
87 static ssize_t show_client_name(struct device *dev, char *buf)
89 struct i2c_client *client = to_i2c_client(dev);
90 return sprintf(buf, "%s\n", client->name);
94 * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
95 * different type of a device. So beware if the DEVICE_ATTR() macro ever
96 * changes, this definition will also have to change.
98 static struct device_attribute dev_attr_client_name = {
99 .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
100 .show = &show_client_name,
104 /* ---------------------------------------------------
105 * registering functions
106 * ---------------------------------------------------
110 * i2c_add_adapter is called from within the algorithm layer,
111 * when a new hw adapter registers. A new device is register to be
112 * available for clients.
114 int i2c_add_adapter(struct i2c_adapter *adap)
117 struct list_head *item;
118 struct i2c_driver *driver;
123 init_MUTEX(&adap->bus_lock);
124 init_MUTEX(&adap->clist_lock);
125 list_add_tail(&adap->list,&adapters);
126 INIT_LIST_HEAD(&adap->clients);
128 /* Add the adapter to the driver core.
129 * If the parent pointer is not set up,
130 * we add this adapter to the host bus.
132 if (adap->dev.parent == NULL)
133 adap->dev.parent = &platform_bus;
134 sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
135 adap->dev.driver = &i2c_adapter_driver;
136 adap->dev.release = &i2c_adapter_dev_release;
137 device_register(&adap->dev);
138 device_create_file(&adap->dev, &dev_attr_name);
140 /* Add this adapter to the i2c_adapter class */
141 memset(&adap->class_dev, 0x00, sizeof(struct class_device));
142 adap->class_dev.dev = &adap->dev;
143 adap->class_dev.class = &i2c_adapter_class;
144 strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
145 class_device_register(&adap->class_dev);
147 /* inform drivers of new adapters */
148 list_for_each(item,&drivers) {
149 driver = list_entry(item, struct i2c_driver, list);
150 if (driver->flags & I2C_DF_NOTIFY)
151 /* We ignore the return code; if it fails, too bad */
152 driver->attach_adapter(adap);
156 dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
161 int i2c_del_adapter(struct i2c_adapter *adap)
163 struct list_head *item, *_n;
164 struct i2c_driver *driver;
165 struct i2c_client *client;
170 list_for_each(item,&drivers) {
171 driver = list_entry(item, struct i2c_driver, list);
172 if (driver->detach_adapter)
173 if ((res = driver->detach_adapter(adap))) {
174 dev_warn(&adap->dev, "can't detach adapter "
175 "while detaching driver %s: driver not "
176 "detached!", driver->name);
181 /* detach any active clients. This must be done first, because
182 * it can fail; in which case we give upp. */
183 list_for_each_safe(item, _n, &adap->clients) {
184 client = list_entry(item, struct i2c_client, list);
186 /* detaching devices is unconditional of the set notify
187 * flag, as _all_ clients that reside on the adapter
188 * must be deleted, as this would cause invalid states.
190 if ((res=client->driver->detach_client(client))) {
191 dev_err(&adap->dev, "adapter not "
192 "unregistered, because client at "
193 "address %02x can't be detached. ",
199 /* clean up the sysfs representation */
200 init_completion(&adap->dev_released);
201 init_completion(&adap->class_dev_released);
202 class_device_unregister(&adap->class_dev);
203 device_remove_file(&adap->dev, &dev_attr_name);
204 device_unregister(&adap->dev);
205 list_del(&adap->list);
207 /* wait for sysfs to drop all references */
208 wait_for_completion(&adap->dev_released);
209 wait_for_completion(&adap->class_dev_released);
211 dev_dbg(&adap->dev, "adapter unregistered\n");
220 * What follows is the "upwards" interface: commands for talking to clients,
221 * which implement the functions to access the physical information of the
225 int i2c_add_driver(struct i2c_driver *driver)
227 struct list_head *item;
228 struct i2c_adapter *adapter;
233 /* add the driver to the list of i2c drivers in the driver core */
234 driver->driver.name = driver->name;
235 driver->driver.bus = &i2c_bus_type;
236 driver->driver.probe = i2c_device_probe;
237 driver->driver.remove = i2c_device_remove;
239 res = driver_register(&driver->driver);
243 list_add_tail(&driver->list,&drivers);
244 pr_debug("i2c-core: driver %s registered.\n", driver->name);
246 /* now look for instances of driver on our adapters */
247 if (driver->flags & I2C_DF_NOTIFY) {
248 list_for_each(item,&adapters) {
249 adapter = list_entry(item, struct i2c_adapter, list);
250 driver->attach_adapter(adapter);
259 int i2c_del_driver(struct i2c_driver *driver)
261 struct list_head *item1, *item2, *_n;
262 struct i2c_client *client;
263 struct i2c_adapter *adap;
269 /* Have a look at each adapter, if clients of this driver are still
270 * attached. If so, detach them to be able to kill the driver
273 pr_debug("i2c-core: unregister_driver - looking for clients.\n");
274 /* removing clients does not depend on the notify flag, else
275 * invalid operation might (will!) result, when using stale client
278 list_for_each(item1,&adapters) {
279 adap = list_entry(item1, struct i2c_adapter, list);
280 dev_dbg(&adap->dev, "examining adapter\n");
281 if (driver->detach_adapter) {
282 if ((res = driver->detach_adapter(adap))) {
283 dev_warn(&adap->dev, "while unregistering "
284 "dummy driver %s, adapter could "
285 "not be detached properly; driver "
286 "not unloaded!",driver->name);
290 list_for_each_safe(item2, _n, &adap->clients) {
291 client = list_entry(item2, struct i2c_client, list);
292 if (client->driver != driver)
294 pr_debug("i2c-core.o: detaching client %s:\n", client->name);
295 if ((res = driver->detach_client(client))) {
296 dev_err(&adap->dev, "while "
297 "unregistering driver "
298 "`%s', the client at "
301 "be detached; driver "
311 driver_unregister(&driver->driver);
312 list_del(&driver->list);
313 pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
320 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
322 struct list_head *item;
323 struct i2c_client *client;
325 list_for_each(item,&adapter->clients) {
326 client = list_entry(item, struct i2c_client, list);
327 if (client->addr == addr)
333 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
337 down(&adapter->clist_lock);
338 rval = __i2c_check_addr(adapter, addr);
339 up(&adapter->clist_lock);
344 int i2c_attach_client(struct i2c_client *client)
346 struct i2c_adapter *adapter = client->adapter;
348 down(&adapter->clist_lock);
349 if (__i2c_check_addr(client->adapter, client->addr)) {
350 up(&adapter->clist_lock);
353 list_add_tail(&client->list,&adapter->clients);
354 up(&adapter->clist_lock);
356 if (adapter->client_register) {
357 if (adapter->client_register(client)) {
358 dev_warn(&adapter->dev, "warning: client_register "
359 "seems to have failed for client %02x\n",
364 dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
367 if (client->flags & I2C_CLIENT_ALLOW_USE)
368 client->usage_count = 0;
370 client->dev.parent = &client->adapter->dev;
371 client->dev.driver = &client->driver->driver;
372 client->dev.bus = &i2c_bus_type;
373 client->dev.release = &i2c_client_release;
375 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
376 "%d-%04x", i2c_adapter_id(adapter), client->addr);
377 pr_debug("registering %s\n", client->dev.bus_id);
378 device_register(&client->dev);
379 device_create_file(&client->dev, &dev_attr_client_name);
385 int i2c_detach_client(struct i2c_client *client)
387 struct i2c_adapter *adapter = client->adapter;
390 if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
393 if (adapter->client_unregister) {
394 res = adapter->client_unregister(client);
396 dev_err(&client->dev,
397 "client_unregister [%s] failed, "
398 "client not detached", client->name);
403 down(&adapter->clist_lock);
404 list_del(&client->list);
405 init_completion(&client->released);
406 device_remove_file(&client->dev, &dev_attr_client_name);
407 device_unregister(&client->dev);
408 up(&adapter->clist_lock);
409 wait_for_completion(&client->released);
415 static int i2c_inc_use_client(struct i2c_client *client)
418 if (!try_module_get(client->driver->owner))
420 if (!try_module_get(client->adapter->owner)) {
421 module_put(client->driver->owner);
428 static void i2c_dec_use_client(struct i2c_client *client)
430 module_put(client->driver->owner);
431 module_put(client->adapter->owner);
434 int i2c_use_client(struct i2c_client *client)
438 ret = i2c_inc_use_client(client);
442 if (client->flags & I2C_CLIENT_ALLOW_USE) {
443 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
444 client->usage_count++;
445 else if (client->usage_count > 0)
448 client->usage_count++;
453 i2c_dec_use_client(client);
457 int i2c_release_client(struct i2c_client *client)
459 if(client->flags & I2C_CLIENT_ALLOW_USE) {
460 if(client->usage_count>0)
461 client->usage_count--;
463 pr_debug("i2c-core: %s used one too many times\n",
469 i2c_dec_use_client(client);
474 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
476 struct list_head *item;
477 struct i2c_client *client;
479 down(&adap->clist_lock);
480 list_for_each(item,&adap->clients) {
481 client = list_entry(item, struct i2c_client, list);
482 if (!try_module_get(client->driver->owner))
484 if (NULL != client->driver->command) {
485 up(&adap->clist_lock);
486 client->driver->command(client,cmd,arg);
487 down(&adap->clist_lock);
489 module_put(client->driver->owner);
491 up(&adap->clist_lock);
495 /* match always succeeds, as we want the probe() to tell if we really accept this match */
496 static int i2c_device_match(struct device *dev, struct device_driver *drv)
501 struct bus_type i2c_bus_type = {
503 .match = i2c_device_match,
506 static int __init i2c_init(void)
510 retval = bus_register(&i2c_bus_type);
513 retval = driver_register(&i2c_adapter_driver);
516 return class_register(&i2c_adapter_class);
519 static void __exit i2c_exit(void)
521 class_unregister(&i2c_adapter_class);
522 driver_unregister(&i2c_adapter_driver);
523 bus_unregister(&i2c_bus_type);
526 subsys_initcall(i2c_init);
527 module_exit(i2c_exit);
529 /* ----------------------------------------------------
530 * the functional interface to the i2c busses.
531 * ----------------------------------------------------
534 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg msgs[],int num)
538 if (adap->algo->master_xfer) {
539 dev_dbg(&adap->dev, "master_xfer: with %d msgs.\n", num);
541 down(&adap->bus_lock);
542 ret = adap->algo->master_xfer(adap,msgs,num);
547 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
552 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
555 struct i2c_adapter *adap=client->adapter;
558 if (client->adapter->algo->master_xfer) {
559 msg.addr = client->addr;
560 msg.flags = client->flags & I2C_M_TEN;
562 msg.buf = (char *)buf;
564 dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
567 down(&adap->bus_lock);
568 ret = adap->algo->master_xfer(adap,&msg,1);
571 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
572 * transmitted, else error code.
574 return (ret == 1 )? count : ret;
576 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
581 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
583 struct i2c_adapter *adap=client->adapter;
586 if (client->adapter->algo->master_xfer) {
587 msg.addr = client->addr;
588 msg.flags = client->flags & I2C_M_TEN;
589 msg.flags |= I2C_M_RD;
593 dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
596 down(&adap->bus_lock);
597 ret = adap->algo->master_xfer(adap,&msg,1);
600 dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
601 ret, count, client->addr);
603 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
604 * transmitted, else error code.
606 return (ret == 1 )? count : ret;
608 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
614 int i2c_control(struct i2c_client *client,
615 unsigned int cmd, unsigned long arg)
618 struct i2c_adapter *adap = client->adapter;
620 dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
629 if (adap->algo->algo_control!=NULL)
630 ret = adap->algo->algo_control(adap,cmd,arg);
635 /* ----------------------------------------------------
636 * the i2c address scanning function
637 * Will not work for 10-bit addresses!
638 * ----------------------------------------------------
640 int i2c_probe(struct i2c_adapter *adapter,
641 struct i2c_client_address_data *address_data,
642 int (*found_proc) (struct i2c_adapter *, int, int))
644 int addr,i,found,err;
645 int adap_id = i2c_adapter_id(adapter);
647 /* Forget it if we can't probe using SMBUS_QUICK */
648 if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
651 for (addr = 0x00; addr <= 0x7f; addr++) {
653 /* Skip if already in use */
654 if (i2c_check_addr(adapter,addr))
657 /* If it is in one of the force entries, we don't do any detection
661 for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 3) {
662 if (((adap_id == address_data->force[i]) ||
663 (address_data->force[i] == ANY_I2C_BUS)) &&
664 (addr == address_data->force[i+1])) {
665 dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
667 if ((err = found_proc(adapter,addr,0)))
675 /* If this address is in one of the ignores, we can forget about
678 !found && (address_data->ignore[i] != I2C_CLIENT_END);
680 if (((adap_id == address_data->ignore[i]) ||
681 ((address_data->ignore[i] == ANY_I2C_BUS))) &&
682 (addr == address_data->ignore[i+1])) {
683 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
684 "addr %04x\n", adap_id ,addr);
689 !found && (address_data->ignore_range[i] != I2C_CLIENT_END);
691 if (((adap_id == address_data->ignore_range[i]) ||
692 ((address_data->ignore_range[i]==ANY_I2C_BUS))) &&
693 (addr >= address_data->ignore_range[i+1]) &&
694 (addr <= address_data->ignore_range[i+2])) {
695 dev_dbg(&adapter->dev, "found ignore_range parameter for adapter %d, "
696 "addr %04x\n", adap_id,addr);
703 /* Now, we will do a detection, but only if it is in the normal or
706 !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
708 if (addr == address_data->normal_i2c[i]) {
710 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
711 "addr %02x", adap_id,addr);
716 !found && (address_data->normal_i2c_range[i] != I2C_CLIENT_END);
718 if ((addr >= address_data->normal_i2c_range[i]) &&
719 (addr <= address_data->normal_i2c_range[i+1])) {
721 dev_dbg(&adapter->dev, "found normal i2c_range entry for adapter %d, "
722 "addr %04x\n", adap_id,addr);
727 !found && (address_data->probe[i] != I2C_CLIENT_END);
729 if (((adap_id == address_data->probe[i]) ||
730 ((address_data->probe[i] == ANY_I2C_BUS))) &&
731 (addr == address_data->probe[i+1])) {
733 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
734 "addr %04x\n", adap_id,addr);
738 !found && (address_data->probe_range[i] != I2C_CLIENT_END);
740 if (((adap_id == address_data->probe_range[i]) ||
741 (address_data->probe_range[i] == ANY_I2C_BUS)) &&
742 (addr >= address_data->probe_range[i+1]) &&
743 (addr <= address_data->probe_range[i+2])) {
745 dev_dbg(&adapter->dev, "found probe_range parameter for adapter %d, "
746 "addr %04x\n", adap_id,addr);
752 /* OK, so we really should examine this address. First check
753 whether there is some client here at all! */
754 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
755 if ((err = found_proc(adapter,addr,-1)))
762 * return id number for a specific adapter
764 int i2c_adapter_id(struct i2c_adapter *adap)
769 struct i2c_adapter* i2c_get_adapter(int id)
771 struct list_head *item;
772 struct i2c_adapter *adapter;
775 list_for_each(item,&adapters) {
776 adapter = list_entry(item, struct i2c_adapter, list);
777 if (id == adapter->nr &&
778 try_module_get(adapter->owner)) {
787 void i2c_put_adapter(struct i2c_adapter *adap)
789 module_put(adap->owner);
792 /* The SMBus parts */
794 #define POLY (0x1070U << 3)
800 for(i = 0; i < 8; i++) {
805 return (u8)(data >> 8);
808 /* CRC over count bytes in the first array plus the bytes in the rest
809 array if it is non-null. rest[0] is the (length of rest) - 1
811 u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
815 for(i = 0; i < count; i++)
816 crc = crc8((crc ^ first[i]) << 8);
818 for(i = 0; i <= rest[0]; i++)
819 crc = crc8((crc ^ rest[i]) << 8);
823 u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
825 return i2c_smbus_partial_pec(0, count, first, rest);
828 /* Returns new "size" (transaction type)
829 Note that we convert byte to byte_data and byte_data to word_data
830 rather than invent new xxx_PEC transactions. */
831 int i2c_smbus_add_pec(u16 addr, u8 command, int size,
832 union i2c_smbus_data *data)
840 data->byte = i2c_smbus_pec(2, buf, NULL);
841 size = I2C_SMBUS_BYTE_DATA;
843 case I2C_SMBUS_BYTE_DATA:
845 data->word = buf[2] ||
846 (i2c_smbus_pec(3, buf, NULL) << 8);
847 size = I2C_SMBUS_WORD_DATA;
849 case I2C_SMBUS_WORD_DATA:
852 case I2C_SMBUS_BLOCK_DATA:
853 data->block[data->block[0] + 1] =
854 i2c_smbus_pec(2, buf, data->block);
855 size = I2C_SMBUS_BLOCK_DATA_PEC;
861 int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
862 union i2c_smbus_data *data)
864 u8 buf[3], rpec, cpec;
868 case I2C_SMBUS_BYTE_DATA:
869 buf[0] = (addr << 1) | 1;
870 cpec = i2c_smbus_pec(2, buf, NULL);
873 case I2C_SMBUS_WORD_DATA:
874 buf[0] = (addr << 1) | 1;
875 buf[2] = data->word & 0xff;
876 cpec = i2c_smbus_pec(3, buf, NULL);
877 rpec = data->word >> 8;
879 case I2C_SMBUS_WORD_DATA_PEC:
883 case I2C_SMBUS_PROC_CALL_PEC:
887 case I2C_SMBUS_BLOCK_DATA_PEC:
888 buf[0] = (addr << 1);
889 buf[2] = (addr << 1) | 1;
890 cpec = i2c_smbus_pec(3, buf, data->block);
891 rpec = data->block[data->block[0] + 1];
893 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
894 buf[0] = (addr << 1) | 1;
895 rpec = i2c_smbus_partial_pec(partial, 1,
897 cpec = data->block[data->block[0] + 1];
904 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
911 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
913 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
914 value,0,I2C_SMBUS_QUICK,NULL);
917 s32 i2c_smbus_read_byte(struct i2c_client *client)
919 union i2c_smbus_data data;
920 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
921 I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
924 return 0x0FF & data.byte;
927 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
929 union i2c_smbus_data data; /* only for PEC */
930 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
931 I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
934 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
936 union i2c_smbus_data data;
937 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
938 I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
941 return 0x0FF & data.byte;
944 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
946 union i2c_smbus_data data;
948 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
949 I2C_SMBUS_WRITE,command,
950 I2C_SMBUS_BYTE_DATA,&data);
953 s32 i2c_smbus_read_word_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_WORD_DATA, &data))
960 return 0x0FFFF & data.word;
963 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 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_WORD_DATA,&data);
972 s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
974 union i2c_smbus_data data;
976 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
977 I2C_SMBUS_WRITE,command,
978 I2C_SMBUS_PROC_CALL, &data))
981 return 0x0FFFF & data.word;
984 /* Returns the number of read bytes */
985 s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, u8 *values)
987 union i2c_smbus_data data;
989 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
990 I2C_SMBUS_READ,command,
991 I2C_SMBUS_BLOCK_DATA,&data))
994 for (i = 1; i <= data.block[0]; i++)
995 values[i-1] = data.block[i];
996 return data.block[0];
1000 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values)
1002 union i2c_smbus_data data;
1004 if (length > I2C_SMBUS_BLOCK_MAX)
1005 length = I2C_SMBUS_BLOCK_MAX;
1006 for (i = 1; i <= length; i++)
1007 data.block[i] = values[i-1];
1008 data.block[0] = length;
1009 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1010 I2C_SMBUS_WRITE,command,
1011 I2C_SMBUS_BLOCK_DATA,&data);
1014 /* Returns the number of read bytes */
1015 s32 i2c_smbus_block_process_call(struct i2c_client *client, u8 command, u8 length, u8 *values)
1017 union i2c_smbus_data data;
1019 if (length > I2C_SMBUS_BLOCK_MAX - 1)
1021 data.block[0] = length;
1022 for (i = 1; i <= length; i++)
1023 data.block[i] = values[i-1];
1024 if(i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1025 I2C_SMBUS_WRITE, command,
1026 I2C_SMBUS_BLOCK_PROC_CALL, &data))
1028 for (i = 1; i <= data.block[0]; i++)
1029 values[i-1] = data.block[i];
1030 return data.block[0];
1033 /* Returns the number of read bytes */
1034 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1036 union i2c_smbus_data data;
1038 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1039 I2C_SMBUS_READ,command,
1040 I2C_SMBUS_I2C_BLOCK_DATA,&data))
1043 for (i = 1; i <= data.block[0]; i++)
1044 values[i-1] = data.block[i];
1045 return data.block[0];
1049 s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values)
1051 union i2c_smbus_data data;
1053 if (length > I2C_SMBUS_I2C_BLOCK_MAX)
1054 length = I2C_SMBUS_I2C_BLOCK_MAX;
1055 for (i = 1; i <= length; i++)
1056 data.block[i] = values[i-1];
1057 data.block[0] = length;
1058 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1059 I2C_SMBUS_WRITE,command,
1060 I2C_SMBUS_I2C_BLOCK_DATA,&data);
1063 /* Simulate a SMBus command using the i2c protocol
1064 No checking of parameters is done! */
1065 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1066 unsigned short flags,
1067 char read_write, u8 command, int size,
1068 union i2c_smbus_data * data)
1070 /* So we need to generate a series of msgs. In the case of writing, we
1071 need to use only one message; when reading, we need two. We initialize
1072 most things with sane defaults, to keep the code below somewhat
1074 unsigned char msgbuf0[34];
1075 unsigned char msgbuf1[34];
1076 int num = read_write == I2C_SMBUS_READ?2:1;
1077 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1078 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1082 msgbuf0[0] = command;
1084 case I2C_SMBUS_QUICK:
1086 /* Special case: The read/write field is used as data */
1087 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1090 case I2C_SMBUS_BYTE:
1091 if (read_write == I2C_SMBUS_READ) {
1092 /* Special case: only a read! */
1093 msg[0].flags = I2C_M_RD | flags;
1097 case I2C_SMBUS_BYTE_DATA:
1098 if (read_write == I2C_SMBUS_READ)
1102 msgbuf0[1] = data->byte;
1105 case I2C_SMBUS_WORD_DATA:
1106 if (read_write == I2C_SMBUS_READ)
1110 msgbuf0[1] = data->word & 0xff;
1111 msgbuf0[2] = (data->word >> 8) & 0xff;
1114 case I2C_SMBUS_PROC_CALL:
1115 num = 2; /* Special case */
1116 read_write = I2C_SMBUS_READ;
1119 msgbuf0[1] = data->word & 0xff;
1120 msgbuf0[2] = (data->word >> 8) & 0xff;
1122 case I2C_SMBUS_BLOCK_DATA:
1123 case I2C_SMBUS_BLOCK_DATA_PEC:
1124 if (read_write == I2C_SMBUS_READ) {
1125 dev_err(&adapter->dev, "Block read not supported "
1126 "under I2C emulation!\n");
1129 msg[0].len = data->block[0] + 2;
1130 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1131 dev_err(&adapter->dev, "smbus_access called with "
1132 "invalid block write size (%d)\n",
1136 if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1138 for (i = 1; i <= msg[0].len; i++)
1139 msgbuf0[i] = data->block[i-1];
1142 case I2C_SMBUS_BLOCK_PROC_CALL:
1143 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1144 dev_dbg(&adapter->dev, "Block process call not supported "
1145 "under I2C emulation!\n");
1147 case I2C_SMBUS_I2C_BLOCK_DATA:
1148 if (read_write == I2C_SMBUS_READ) {
1149 msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1151 msg[0].len = data->block[0] + 1;
1152 if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1153 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1154 "invalid block write size (%d)\n",
1158 for (i = 1; i <= data->block[0]; i++)
1159 msgbuf0[i] = data->block[i];
1163 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1168 if (i2c_transfer(adapter, msg, num) < 0)
1171 if (read_write == I2C_SMBUS_READ)
1173 case I2C_SMBUS_BYTE:
1174 data->byte = msgbuf0[0];
1176 case I2C_SMBUS_BYTE_DATA:
1177 data->byte = msgbuf1[0];
1179 case I2C_SMBUS_WORD_DATA:
1180 case I2C_SMBUS_PROC_CALL:
1181 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1183 case I2C_SMBUS_I2C_BLOCK_DATA:
1184 /* fixed at 32 for now */
1185 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1186 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1187 data->block[i+1] = msgbuf1[i];
1194 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1195 char read_write, u8 command, int size,
1196 union i2c_smbus_data * data)
1202 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1203 if((flags & I2C_CLIENT_PEC) &&
1204 !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1206 if(read_write == I2C_SMBUS_READ &&
1207 size == I2C_SMBUS_BLOCK_DATA)
1208 size = I2C_SMBUS_BLOCK_DATA_PEC;
1209 else if(size == I2C_SMBUS_PROC_CALL)
1210 size = I2C_SMBUS_PROC_CALL_PEC;
1211 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1212 i2c_smbus_add_pec(addr, command,
1213 I2C_SMBUS_BLOCK_DATA, data);
1214 partial = data->block[data->block[0] + 1];
1215 size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1216 } else if(read_write == I2C_SMBUS_WRITE &&
1217 size != I2C_SMBUS_QUICK &&
1218 size != I2C_SMBUS_I2C_BLOCK_DATA)
1219 size = i2c_smbus_add_pec(addr, command, size, data);
1222 if (adapter->algo->smbus_xfer) {
1223 down(&adapter->bus_lock);
1224 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1226 up(&adapter->bus_lock);
1228 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1231 if(res >= 0 && swpec &&
1232 size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1233 (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1234 size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1235 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1242 /* You should always define `functionality'; the 'else' is just for
1243 backward compatibility. */
1244 u32 i2c_get_functionality (struct i2c_adapter *adap)
1246 if (adap->algo->functionality)
1247 return adap->algo->functionality(adap);
1252 int i2c_check_functionality (struct i2c_adapter *adap, u32 func)
1254 u32 adap_func = i2c_get_functionality (adap);
1255 return (func & adap_func) == func;
1258 EXPORT_SYMBOL(i2c_add_adapter);
1259 EXPORT_SYMBOL(i2c_del_adapter);
1260 EXPORT_SYMBOL(i2c_add_driver);
1261 EXPORT_SYMBOL(i2c_del_driver);
1262 EXPORT_SYMBOL(i2c_attach_client);
1263 EXPORT_SYMBOL(i2c_detach_client);
1264 EXPORT_SYMBOL(i2c_use_client);
1265 EXPORT_SYMBOL(i2c_release_client);
1266 EXPORT_SYMBOL(i2c_clients_command);
1267 EXPORT_SYMBOL(i2c_check_addr);
1269 EXPORT_SYMBOL(i2c_master_send);
1270 EXPORT_SYMBOL(i2c_master_recv);
1271 EXPORT_SYMBOL(i2c_control);
1272 EXPORT_SYMBOL(i2c_transfer);
1273 EXPORT_SYMBOL(i2c_adapter_id);
1274 EXPORT_SYMBOL(i2c_get_adapter);
1275 EXPORT_SYMBOL(i2c_put_adapter);
1276 EXPORT_SYMBOL(i2c_probe);
1278 EXPORT_SYMBOL(i2c_smbus_xfer);
1279 EXPORT_SYMBOL(i2c_smbus_write_quick);
1280 EXPORT_SYMBOL(i2c_smbus_read_byte);
1281 EXPORT_SYMBOL(i2c_smbus_write_byte);
1282 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1283 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1284 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1285 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1286 EXPORT_SYMBOL(i2c_smbus_process_call);
1287 EXPORT_SYMBOL(i2c_smbus_read_block_data);
1288 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1289 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1290 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1292 EXPORT_SYMBOL(i2c_get_functionality);
1293 EXPORT_SYMBOL(i2c_check_functionality);
1295 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1296 MODULE_DESCRIPTION("I2C-Bus main module");
1297 MODULE_LICENSE("GPL");