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 id = idr_get_new(&i2c_adapter_idr, NULL);
130 adap->nr = id & MAX_ID_MASK;
131 init_MUTEX(&adap->bus_lock);
132 init_MUTEX(&adap->clist_lock);
133 list_add_tail(&adap->list,&adapters);
134 INIT_LIST_HEAD(&adap->clients);
136 /* Add the adapter to the driver core.
137 * If the parent pointer is not set up,
138 * we add this adapter to the host bus.
140 if (adap->dev.parent == NULL)
141 adap->dev.parent = &platform_bus;
142 sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
143 adap->dev.driver = &i2c_adapter_driver;
144 adap->dev.release = &i2c_adapter_dev_release;
145 device_register(&adap->dev);
146 device_create_file(&adap->dev, &dev_attr_name);
148 /* Add this adapter to the i2c_adapter class */
149 memset(&adap->class_dev, 0x00, sizeof(struct class_device));
150 adap->class_dev.dev = &adap->dev;
151 adap->class_dev.class = &i2c_adapter_class;
152 strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
153 class_device_register(&adap->class_dev);
155 /* inform drivers of new adapters */
156 list_for_each(item,&drivers) {
157 driver = list_entry(item, struct i2c_driver, list);
158 if (driver->flags & I2C_DF_NOTIFY)
159 /* We ignore the return code; if it fails, too bad */
160 driver->attach_adapter(adap);
163 dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
171 int i2c_del_adapter(struct i2c_adapter *adap)
173 struct list_head *item, *_n;
174 struct i2c_driver *driver;
175 struct i2c_client *client;
180 list_for_each(item,&drivers) {
181 driver = list_entry(item, struct i2c_driver, list);
182 if (driver->detach_adapter)
183 if ((res = driver->detach_adapter(adap))) {
184 dev_warn(&adap->dev, "can't detach adapter "
185 "while detaching driver %s: driver not "
186 "detached!", driver->name);
191 /* detach any active clients. This must be done first, because
192 * it can fail; in which case we give upp. */
193 list_for_each_safe(item, _n, &adap->clients) {
194 client = list_entry(item, struct i2c_client, list);
196 /* detaching devices is unconditional of the set notify
197 * flag, as _all_ clients that reside on the adapter
198 * must be deleted, as this would cause invalid states.
200 if ((res=client->driver->detach_client(client))) {
201 dev_err(&adap->dev, "adapter not "
202 "unregistered, because client at "
203 "address %02x can't be detached. ",
209 /* clean up the sysfs representation */
210 init_completion(&adap->dev_released);
211 init_completion(&adap->class_dev_released);
212 class_device_unregister(&adap->class_dev);
213 device_remove_file(&adap->dev, &dev_attr_name);
214 device_unregister(&adap->dev);
215 list_del(&adap->list);
217 /* wait for sysfs to drop all references */
218 wait_for_completion(&adap->dev_released);
219 wait_for_completion(&adap->class_dev_released);
221 /* free dynamically allocated bus id */
222 idr_remove(&i2c_adapter_idr, adap->nr);
224 dev_dbg(&adap->dev, "adapter unregistered\n");
233 * What follows is the "upwards" interface: commands for talking to clients,
234 * which implement the functions to access the physical information of the
238 int i2c_add_driver(struct i2c_driver *driver)
240 struct list_head *item;
241 struct i2c_adapter *adapter;
246 /* add the driver to the list of i2c drivers in the driver core */
247 driver->driver.name = driver->name;
248 driver->driver.bus = &i2c_bus_type;
249 driver->driver.probe = i2c_device_probe;
250 driver->driver.remove = i2c_device_remove;
252 res = driver_register(&driver->driver);
256 list_add_tail(&driver->list,&drivers);
257 pr_debug("i2c-core: driver %s registered.\n", driver->name);
259 /* now look for instances of driver on our adapters */
260 if (driver->flags & I2C_DF_NOTIFY) {
261 list_for_each(item,&adapters) {
262 adapter = list_entry(item, struct i2c_adapter, list);
263 driver->attach_adapter(adapter);
272 int i2c_del_driver(struct i2c_driver *driver)
274 struct list_head *item1, *item2, *_n;
275 struct i2c_client *client;
276 struct i2c_adapter *adap;
282 /* Have a look at each adapter, if clients of this driver are still
283 * attached. If so, detach them to be able to kill the driver
286 pr_debug("i2c-core: unregister_driver - looking for clients.\n");
287 /* removing clients does not depend on the notify flag, else
288 * invalid operation might (will!) result, when using stale client
291 list_for_each(item1,&adapters) {
292 adap = list_entry(item1, struct i2c_adapter, list);
293 dev_dbg(&adap->dev, "examining adapter\n");
294 if (driver->detach_adapter) {
295 if ((res = driver->detach_adapter(adap))) {
296 dev_warn(&adap->dev, "while unregistering "
297 "dummy driver %s, adapter could "
298 "not be detached properly; driver "
299 "not unloaded!",driver->name);
303 list_for_each_safe(item2, _n, &adap->clients) {
304 client = list_entry(item2, struct i2c_client, list);
305 if (client->driver != driver)
307 pr_debug("i2c-core.o: detaching client %s:\n", client->name);
308 if ((res = driver->detach_client(client))) {
309 dev_err(&adap->dev, "while "
310 "unregistering driver "
311 "`%s', the client at "
314 "be detached; driver "
324 driver_unregister(&driver->driver);
325 list_del(&driver->list);
326 pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
333 static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
335 struct list_head *item;
336 struct i2c_client *client;
338 list_for_each(item,&adapter->clients) {
339 client = list_entry(item, struct i2c_client, list);
340 if (client->addr == addr)
346 int i2c_check_addr(struct i2c_adapter *adapter, int addr)
350 down(&adapter->clist_lock);
351 rval = __i2c_check_addr(adapter, addr);
352 up(&adapter->clist_lock);
357 int i2c_attach_client(struct i2c_client *client)
359 struct i2c_adapter *adapter = client->adapter;
361 down(&adapter->clist_lock);
362 if (__i2c_check_addr(client->adapter, client->addr)) {
363 up(&adapter->clist_lock);
366 list_add_tail(&client->list,&adapter->clients);
367 up(&adapter->clist_lock);
369 if (adapter->client_register) {
370 if (adapter->client_register(client)) {
371 dev_warn(&adapter->dev, "warning: client_register "
372 "seems to have failed for client %02x\n",
377 dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
380 if (client->flags & I2C_CLIENT_ALLOW_USE)
381 client->usage_count = 0;
383 client->dev.parent = &client->adapter->dev;
384 client->dev.driver = &client->driver->driver;
385 client->dev.bus = &i2c_bus_type;
386 client->dev.release = &i2c_client_release;
388 snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
389 "%d-%04x", i2c_adapter_id(adapter), client->addr);
390 pr_debug("registering %s\n", client->dev.bus_id);
391 device_register(&client->dev);
392 device_create_file(&client->dev, &dev_attr_client_name);
398 int i2c_detach_client(struct i2c_client *client)
400 struct i2c_adapter *adapter = client->adapter;
403 if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
406 if (adapter->client_unregister) {
407 res = adapter->client_unregister(client);
409 dev_err(&client->dev,
410 "client_unregister [%s] failed, "
411 "client not detached", client->name);
416 down(&adapter->clist_lock);
417 list_del(&client->list);
418 init_completion(&client->released);
419 device_remove_file(&client->dev, &dev_attr_client_name);
420 device_unregister(&client->dev);
421 up(&adapter->clist_lock);
422 wait_for_completion(&client->released);
428 static int i2c_inc_use_client(struct i2c_client *client)
431 if (!try_module_get(client->driver->owner))
433 if (!try_module_get(client->adapter->owner)) {
434 module_put(client->driver->owner);
441 static void i2c_dec_use_client(struct i2c_client *client)
443 module_put(client->driver->owner);
444 module_put(client->adapter->owner);
447 int i2c_use_client(struct i2c_client *client)
451 ret = i2c_inc_use_client(client);
455 if (client->flags & I2C_CLIENT_ALLOW_USE) {
456 if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
457 client->usage_count++;
458 else if (client->usage_count > 0)
461 client->usage_count++;
466 i2c_dec_use_client(client);
470 int i2c_release_client(struct i2c_client *client)
472 if(client->flags & I2C_CLIENT_ALLOW_USE) {
473 if(client->usage_count>0)
474 client->usage_count--;
476 pr_debug("i2c-core: %s used one too many times\n",
482 i2c_dec_use_client(client);
487 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
489 struct list_head *item;
490 struct i2c_client *client;
492 down(&adap->clist_lock);
493 list_for_each(item,&adap->clients) {
494 client = list_entry(item, struct i2c_client, list);
495 if (!try_module_get(client->driver->owner))
497 if (NULL != client->driver->command) {
498 up(&adap->clist_lock);
499 client->driver->command(client,cmd,arg);
500 down(&adap->clist_lock);
502 module_put(client->driver->owner);
504 up(&adap->clist_lock);
508 /* match always succeeds, as we want the probe() to tell if we really accept this match */
509 static int i2c_device_match(struct device *dev, struct device_driver *drv)
514 struct bus_type i2c_bus_type = {
516 .match = i2c_device_match,
519 static int __init i2c_init(void)
523 retval = bus_register(&i2c_bus_type);
526 retval = driver_register(&i2c_adapter_driver);
529 return class_register(&i2c_adapter_class);
532 static void __exit i2c_exit(void)
534 class_unregister(&i2c_adapter_class);
535 driver_unregister(&i2c_adapter_driver);
536 bus_unregister(&i2c_bus_type);
539 subsys_initcall(i2c_init);
540 module_exit(i2c_exit);
542 /* ----------------------------------------------------
543 * the functional interface to the i2c busses.
544 * ----------------------------------------------------
547 int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg msgs[],int num)
551 if (adap->algo->master_xfer) {
552 dev_dbg(&adap->dev, "master_xfer: with %d msgs.\n", num);
554 down(&adap->bus_lock);
555 ret = adap->algo->master_xfer(adap,msgs,num);
560 dev_dbg(&adap->dev, "I2C level transfers not supported\n");
565 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
568 struct i2c_adapter *adap=client->adapter;
571 if (client->adapter->algo->master_xfer) {
572 msg.addr = client->addr;
573 msg.flags = client->flags & I2C_M_TEN;
575 msg.buf = (char *)buf;
577 dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
580 down(&adap->bus_lock);
581 ret = adap->algo->master_xfer(adap,&msg,1);
584 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
585 * transmitted, else error code.
587 return (ret == 1 )? count : ret;
589 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
594 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
596 struct i2c_adapter *adap=client->adapter;
599 if (client->adapter->algo->master_xfer) {
600 msg.addr = client->addr;
601 msg.flags = client->flags & I2C_M_TEN;
602 msg.flags |= I2C_M_RD;
606 dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
609 down(&adap->bus_lock);
610 ret = adap->algo->master_xfer(adap,&msg,1);
613 dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
614 ret, count, client->addr);
616 /* if everything went ok (i.e. 1 msg transmitted), return #bytes
617 * transmitted, else error code.
619 return (ret == 1 )? count : ret;
621 dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
627 int i2c_control(struct i2c_client *client,
628 unsigned int cmd, unsigned long arg)
631 struct i2c_adapter *adap = client->adapter;
633 dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
642 if (adap->algo->algo_control!=NULL)
643 ret = adap->algo->algo_control(adap,cmd,arg);
648 /* ----------------------------------------------------
649 * the i2c address scanning function
650 * Will not work for 10-bit addresses!
651 * ----------------------------------------------------
653 int i2c_probe(struct i2c_adapter *adapter,
654 struct i2c_client_address_data *address_data,
655 int (*found_proc) (struct i2c_adapter *, int, int))
657 int addr,i,found,err;
658 int adap_id = i2c_adapter_id(adapter);
660 /* Forget it if we can't probe using SMBUS_QUICK */
661 if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
664 for (addr = 0x00; addr <= 0x7f; addr++) {
666 /* Skip if already in use */
667 if (i2c_check_addr(adapter,addr))
670 /* If it is in one of the force entries, we don't do any detection
674 for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 3) {
675 if (((adap_id == address_data->force[i]) ||
676 (address_data->force[i] == ANY_I2C_BUS)) &&
677 (addr == address_data->force[i+1])) {
678 dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
680 if ((err = found_proc(adapter,addr,0)))
688 /* If this address is in one of the ignores, we can forget about
691 !found && (address_data->ignore[i] != I2C_CLIENT_END);
693 if (((adap_id == address_data->ignore[i]) ||
694 ((address_data->ignore[i] == ANY_I2C_BUS))) &&
695 (addr == address_data->ignore[i+1])) {
696 dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
697 "addr %04x\n", adap_id ,addr);
702 !found && (address_data->ignore_range[i] != I2C_CLIENT_END);
704 if (((adap_id == address_data->ignore_range[i]) ||
705 ((address_data->ignore_range[i]==ANY_I2C_BUS))) &&
706 (addr >= address_data->ignore_range[i+1]) &&
707 (addr <= address_data->ignore_range[i+2])) {
708 dev_dbg(&adapter->dev, "found ignore_range parameter for adapter %d, "
709 "addr %04x\n", adap_id,addr);
716 /* Now, we will do a detection, but only if it is in the normal or
719 !found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
721 if (addr == address_data->normal_i2c[i]) {
723 dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
724 "addr %02x", adap_id,addr);
729 !found && (address_data->normal_i2c_range[i] != I2C_CLIENT_END);
731 if ((addr >= address_data->normal_i2c_range[i]) &&
732 (addr <= address_data->normal_i2c_range[i+1])) {
734 dev_dbg(&adapter->dev, "found normal i2c_range entry for adapter %d, "
735 "addr %04x\n", adap_id,addr);
740 !found && (address_data->probe[i] != I2C_CLIENT_END);
742 if (((adap_id == address_data->probe[i]) ||
743 ((address_data->probe[i] == ANY_I2C_BUS))) &&
744 (addr == address_data->probe[i+1])) {
746 dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
747 "addr %04x\n", adap_id,addr);
751 !found && (address_data->probe_range[i] != I2C_CLIENT_END);
753 if (((adap_id == address_data->probe_range[i]) ||
754 (address_data->probe_range[i] == ANY_I2C_BUS)) &&
755 (addr >= address_data->probe_range[i+1]) &&
756 (addr <= address_data->probe_range[i+2])) {
758 dev_dbg(&adapter->dev, "found probe_range parameter for adapter %d, "
759 "addr %04x\n", adap_id,addr);
765 /* OK, so we really should examine this address. First check
766 whether there is some client here at all! */
767 if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
768 if ((err = found_proc(adapter,addr,-1)))
775 * return id number for a specific adapter
777 int i2c_adapter_id(struct i2c_adapter *adap)
782 struct i2c_adapter* i2c_get_adapter(int id)
784 struct list_head *item;
785 struct i2c_adapter *adapter;
788 list_for_each(item,&adapters) {
789 adapter = list_entry(item, struct i2c_adapter, list);
790 if (id == adapter->nr &&
791 try_module_get(adapter->owner)) {
800 void i2c_put_adapter(struct i2c_adapter *adap)
802 module_put(adap->owner);
805 /* The SMBus parts */
807 #define POLY (0x1070U << 3)
813 for(i = 0; i < 8; i++) {
818 return (u8)(data >> 8);
821 /* CRC over count bytes in the first array plus the bytes in the rest
822 array if it is non-null. rest[0] is the (length of rest) - 1
824 u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
828 for(i = 0; i < count; i++)
829 crc = crc8((crc ^ first[i]) << 8);
831 for(i = 0; i <= rest[0]; i++)
832 crc = crc8((crc ^ rest[i]) << 8);
836 u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
838 return i2c_smbus_partial_pec(0, count, first, rest);
841 /* Returns new "size" (transaction type)
842 Note that we convert byte to byte_data and byte_data to word_data
843 rather than invent new xxx_PEC transactions. */
844 int i2c_smbus_add_pec(u16 addr, u8 command, int size,
845 union i2c_smbus_data *data)
853 data->byte = i2c_smbus_pec(2, buf, NULL);
854 size = I2C_SMBUS_BYTE_DATA;
856 case I2C_SMBUS_BYTE_DATA:
858 data->word = buf[2] ||
859 (i2c_smbus_pec(3, buf, NULL) << 8);
860 size = I2C_SMBUS_WORD_DATA;
862 case I2C_SMBUS_WORD_DATA:
865 case I2C_SMBUS_BLOCK_DATA:
866 data->block[data->block[0] + 1] =
867 i2c_smbus_pec(2, buf, data->block);
868 size = I2C_SMBUS_BLOCK_DATA_PEC;
874 int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
875 union i2c_smbus_data *data)
877 u8 buf[3], rpec, cpec;
881 case I2C_SMBUS_BYTE_DATA:
882 buf[0] = (addr << 1) | 1;
883 cpec = i2c_smbus_pec(2, buf, NULL);
886 case I2C_SMBUS_WORD_DATA:
887 buf[0] = (addr << 1) | 1;
888 buf[2] = data->word & 0xff;
889 cpec = i2c_smbus_pec(3, buf, NULL);
890 rpec = data->word >> 8;
892 case I2C_SMBUS_WORD_DATA_PEC:
896 case I2C_SMBUS_PROC_CALL_PEC:
900 case I2C_SMBUS_BLOCK_DATA_PEC:
901 buf[0] = (addr << 1);
902 buf[2] = (addr << 1) | 1;
903 cpec = i2c_smbus_pec(3, buf, data->block);
904 rpec = data->block[data->block[0] + 1];
906 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
907 buf[0] = (addr << 1) | 1;
908 rpec = i2c_smbus_partial_pec(partial, 1,
910 cpec = data->block[data->block[0] + 1];
917 pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
924 s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
926 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
927 value,0,I2C_SMBUS_QUICK,NULL);
930 s32 i2c_smbus_read_byte(struct i2c_client *client)
932 union i2c_smbus_data data;
933 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
934 I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
937 return 0x0FF & data.byte;
940 s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
942 union i2c_smbus_data data; /* only for PEC */
943 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
944 I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
947 s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
949 union i2c_smbus_data data;
950 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
951 I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
954 return 0x0FF & data.byte;
957 s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
959 union i2c_smbus_data data;
961 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
962 I2C_SMBUS_WRITE,command,
963 I2C_SMBUS_BYTE_DATA,&data);
966 s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
968 union i2c_smbus_data data;
969 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
970 I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
973 return 0x0FFFF & data.word;
976 s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
978 union i2c_smbus_data data;
980 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
981 I2C_SMBUS_WRITE,command,
982 I2C_SMBUS_WORD_DATA,&data);
985 s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
987 union i2c_smbus_data data;
989 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
990 I2C_SMBUS_WRITE,command,
991 I2C_SMBUS_PROC_CALL, &data))
994 return 0x0FFFF & data.word;
997 /* Returns the number of read bytes */
998 s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, u8 *values)
1000 union i2c_smbus_data data;
1002 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1003 I2C_SMBUS_READ,command,
1004 I2C_SMBUS_BLOCK_DATA,&data))
1007 for (i = 1; i <= data.block[0]; i++)
1008 values[i-1] = data.block[i];
1009 return data.block[0];
1013 s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values)
1015 union i2c_smbus_data data;
1017 if (length > I2C_SMBUS_BLOCK_MAX)
1018 length = I2C_SMBUS_BLOCK_MAX;
1019 for (i = 1; i <= length; i++)
1020 data.block[i] = values[i-1];
1021 data.block[0] = length;
1022 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1023 I2C_SMBUS_WRITE,command,
1024 I2C_SMBUS_BLOCK_DATA,&data);
1027 /* Returns the number of read bytes */
1028 s32 i2c_smbus_block_process_call(struct i2c_client *client, u8 command, u8 length, u8 *values)
1030 union i2c_smbus_data data;
1032 if (length > I2C_SMBUS_BLOCK_MAX - 1)
1034 data.block[0] = length;
1035 for (i = 1; i <= length; i++)
1036 data.block[i] = values[i-1];
1037 if(i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1038 I2C_SMBUS_WRITE, command,
1039 I2C_SMBUS_BLOCK_PROC_CALL, &data))
1041 for (i = 1; i <= data.block[0]; i++)
1042 values[i-1] = data.block[i];
1043 return data.block[0];
1046 /* Returns the number of read bytes */
1047 s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
1049 union i2c_smbus_data data;
1051 if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1052 I2C_SMBUS_READ,command,
1053 I2C_SMBUS_I2C_BLOCK_DATA,&data))
1056 for (i = 1; i <= data.block[0]; i++)
1057 values[i-1] = data.block[i];
1058 return data.block[0];
1062 s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values)
1064 union i2c_smbus_data data;
1066 if (length > I2C_SMBUS_I2C_BLOCK_MAX)
1067 length = I2C_SMBUS_I2C_BLOCK_MAX;
1068 for (i = 1; i <= length; i++)
1069 data.block[i] = values[i-1];
1070 data.block[0] = length;
1071 return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1072 I2C_SMBUS_WRITE,command,
1073 I2C_SMBUS_I2C_BLOCK_DATA,&data);
1076 /* Simulate a SMBus command using the i2c protocol
1077 No checking of parameters is done! */
1078 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1079 unsigned short flags,
1080 char read_write, u8 command, int size,
1081 union i2c_smbus_data * data)
1083 /* So we need to generate a series of msgs. In the case of writing, we
1084 need to use only one message; when reading, we need two. We initialize
1085 most things with sane defaults, to keep the code below somewhat
1087 unsigned char msgbuf0[34];
1088 unsigned char msgbuf1[34];
1089 int num = read_write == I2C_SMBUS_READ?2:1;
1090 struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1091 { addr, flags | I2C_M_RD, 0, msgbuf1 }
1095 msgbuf0[0] = command;
1097 case I2C_SMBUS_QUICK:
1099 /* Special case: The read/write field is used as data */
1100 msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
1103 case I2C_SMBUS_BYTE:
1104 if (read_write == I2C_SMBUS_READ) {
1105 /* Special case: only a read! */
1106 msg[0].flags = I2C_M_RD | flags;
1110 case I2C_SMBUS_BYTE_DATA:
1111 if (read_write == I2C_SMBUS_READ)
1115 msgbuf0[1] = data->byte;
1118 case I2C_SMBUS_WORD_DATA:
1119 if (read_write == I2C_SMBUS_READ)
1123 msgbuf0[1] = data->word & 0xff;
1124 msgbuf0[2] = (data->word >> 8) & 0xff;
1127 case I2C_SMBUS_PROC_CALL:
1128 num = 2; /* Special case */
1129 read_write = I2C_SMBUS_READ;
1132 msgbuf0[1] = data->word & 0xff;
1133 msgbuf0[2] = (data->word >> 8) & 0xff;
1135 case I2C_SMBUS_BLOCK_DATA:
1136 case I2C_SMBUS_BLOCK_DATA_PEC:
1137 if (read_write == I2C_SMBUS_READ) {
1138 dev_err(&adapter->dev, "Block read not supported "
1139 "under I2C emulation!\n");
1142 msg[0].len = data->block[0] + 2;
1143 if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1144 dev_err(&adapter->dev, "smbus_access called with "
1145 "invalid block write size (%d)\n",
1149 if(size == I2C_SMBUS_BLOCK_DATA_PEC)
1151 for (i = 1; i <= msg[0].len; i++)
1152 msgbuf0[i] = data->block[i-1];
1155 case I2C_SMBUS_BLOCK_PROC_CALL:
1156 case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
1157 dev_dbg(&adapter->dev, "Block process call not supported "
1158 "under I2C emulation!\n");
1160 case I2C_SMBUS_I2C_BLOCK_DATA:
1161 if (read_write == I2C_SMBUS_READ) {
1162 msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
1164 msg[0].len = data->block[0] + 1;
1165 if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
1166 dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
1167 "invalid block write size (%d)\n",
1171 for (i = 1; i <= data->block[0]; i++)
1172 msgbuf0[i] = data->block[i];
1176 dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
1181 if (i2c_transfer(adapter, msg, num) < 0)
1184 if (read_write == I2C_SMBUS_READ)
1186 case I2C_SMBUS_BYTE:
1187 data->byte = msgbuf0[0];
1189 case I2C_SMBUS_BYTE_DATA:
1190 data->byte = msgbuf1[0];
1192 case I2C_SMBUS_WORD_DATA:
1193 case I2C_SMBUS_PROC_CALL:
1194 data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1196 case I2C_SMBUS_I2C_BLOCK_DATA:
1197 /* fixed at 32 for now */
1198 data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
1199 for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
1200 data->block[i+1] = msgbuf1[i];
1207 s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
1208 char read_write, u8 command, int size,
1209 union i2c_smbus_data * data)
1215 flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1216 if((flags & I2C_CLIENT_PEC) &&
1217 !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
1219 if(read_write == I2C_SMBUS_READ &&
1220 size == I2C_SMBUS_BLOCK_DATA)
1221 size = I2C_SMBUS_BLOCK_DATA_PEC;
1222 else if(size == I2C_SMBUS_PROC_CALL)
1223 size = I2C_SMBUS_PROC_CALL_PEC;
1224 else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
1225 i2c_smbus_add_pec(addr, command,
1226 I2C_SMBUS_BLOCK_DATA, data);
1227 partial = data->block[data->block[0] + 1];
1228 size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
1229 } else if(read_write == I2C_SMBUS_WRITE &&
1230 size != I2C_SMBUS_QUICK &&
1231 size != I2C_SMBUS_I2C_BLOCK_DATA)
1232 size = i2c_smbus_add_pec(addr, command, size, data);
1235 if (adapter->algo->smbus_xfer) {
1236 down(&adapter->bus_lock);
1237 res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
1239 up(&adapter->bus_lock);
1241 res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1244 if(res >= 0 && swpec &&
1245 size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
1246 (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
1247 size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
1248 if(i2c_smbus_check_pec(addr, command, size, partial, data))
1255 /* You should always define `functionality'; the 'else' is just for
1256 backward compatibility. */
1257 u32 i2c_get_functionality (struct i2c_adapter *adap)
1259 if (adap->algo->functionality)
1260 return adap->algo->functionality(adap);
1265 int i2c_check_functionality (struct i2c_adapter *adap, u32 func)
1267 u32 adap_func = i2c_get_functionality (adap);
1268 return (func & adap_func) == func;
1271 EXPORT_SYMBOL(i2c_add_adapter);
1272 EXPORT_SYMBOL(i2c_del_adapter);
1273 EXPORT_SYMBOL(i2c_add_driver);
1274 EXPORT_SYMBOL(i2c_del_driver);
1275 EXPORT_SYMBOL(i2c_attach_client);
1276 EXPORT_SYMBOL(i2c_detach_client);
1277 EXPORT_SYMBOL(i2c_use_client);
1278 EXPORT_SYMBOL(i2c_release_client);
1279 EXPORT_SYMBOL(i2c_clients_command);
1280 EXPORT_SYMBOL(i2c_check_addr);
1282 EXPORT_SYMBOL(i2c_master_send);
1283 EXPORT_SYMBOL(i2c_master_recv);
1284 EXPORT_SYMBOL(i2c_control);
1285 EXPORT_SYMBOL(i2c_transfer);
1286 EXPORT_SYMBOL(i2c_adapter_id);
1287 EXPORT_SYMBOL(i2c_get_adapter);
1288 EXPORT_SYMBOL(i2c_put_adapter);
1289 EXPORT_SYMBOL(i2c_probe);
1291 EXPORT_SYMBOL(i2c_smbus_xfer);
1292 EXPORT_SYMBOL(i2c_smbus_write_quick);
1293 EXPORT_SYMBOL(i2c_smbus_read_byte);
1294 EXPORT_SYMBOL(i2c_smbus_write_byte);
1295 EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1296 EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1297 EXPORT_SYMBOL(i2c_smbus_read_word_data);
1298 EXPORT_SYMBOL(i2c_smbus_write_word_data);
1299 EXPORT_SYMBOL(i2c_smbus_process_call);
1300 EXPORT_SYMBOL(i2c_smbus_read_block_data);
1301 EXPORT_SYMBOL(i2c_smbus_write_block_data);
1302 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1303 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1305 EXPORT_SYMBOL(i2c_get_functionality);
1306 EXPORT_SYMBOL(i2c_check_functionality);
1308 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1309 MODULE_DESCRIPTION("I2C-Bus main module");
1310 MODULE_LICENSE("GPL");