libceph: fix messenger retry
[linux-2.6-block.git] / include / linux / i2c.h
CommitLineData
1da177e4 1/* ------------------------------------------------------------------------- */
438d6c2c 2/* */
1da177e4 3/* i2c.h - definitions for the i2c-bus interface */
438d6c2c 4/* */
1da177e4
LT
5/* ------------------------------------------------------------------------- */
6/* Copyright (C) 1995-2000 Simon G. Vogl
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
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20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
21 MA 02110-1301 USA. */
1da177e4
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22/* ------------------------------------------------------------------------- */
23
a1b9298e 24/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
1da177e4
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25 Frodo Looijaard <frodol@dds.nl> */
26
1da177e4
LT
27#ifndef _LINUX_I2C_H
28#define _LINUX_I2C_H
29
1da177e4 30#include <linux/types.h>
438d6c2c 31#ifdef __KERNEL__
a9d1b24d 32#include <linux/mod_devicetable.h>
1da177e4 33#include <linux/device.h> /* for struct device */
4e57b681 34#include <linux/sched.h> /* for completion */
5c085d36 35#include <linux/mutex.h>
d12d42f7 36#include <linux/of.h> /* for struct device_node */
06a67848 37#include <linux/swab.h> /* for swab16 */
1da177e4 38
e9ca9eb9 39extern struct bus_type i2c_bus_type;
0826374b 40extern struct device_type i2c_adapter_type;
e9ca9eb9 41
1da177e4
LT
42/* --- General options ------------------------------------------------ */
43
44struct i2c_msg;
45struct i2c_algorithm;
46struct i2c_adapter;
47struct i2c_client;
48struct i2c_driver;
1da177e4 49union i2c_smbus_data;
4735c98f 50struct i2c_board_info;
1da177e4 51
de477254
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52struct module;
53
23af8400 54#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
1da177e4
LT
55/*
56 * The master routines are the ones normally used to transmit data to devices
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DB
57 * on a bus (or read from them). Apart from two basic transfer functions to
58 * transmit one message at a time, a more complex version can be used to
1da177e4 59 * transmit an arbitrary number of messages without interruption.
0c43ea54 60 * @count must be be less than 64k since msg.len is u16.
1da177e4 61 */
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62extern int i2c_master_send(const struct i2c_client *client, const char *buf,
63 int count);
64extern int i2c_master_recv(const struct i2c_client *client, char *buf,
3ae70dee 65 int count);
1da177e4
LT
66
67/* Transfer num messages.
68 */
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69extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
70 int num);
1da177e4
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71
72/* This is the very generalized SMBus access routine. You probably do not
73 want to use this, though; one of the functions below may be much easier,
438d6c2c 74 and probably just as fast.
1da177e4
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75 Note that we use i2c_adapter here, because you do not need a specific
76 smbus adapter to call this function. */
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77extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
78 unsigned short flags, char read_write, u8 command,
79 int size, union i2c_smbus_data *data);
1da177e4
LT
80
81/* Now follow the 'nice' access routines. These also document the calling
ae7193f7 82 conventions of i2c_smbus_xfer. */
1da177e4 83
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84extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
85extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
86extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
87 u8 command);
88extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
3ae70dee 89 u8 command, u8 value);
0cc43a18
JD
90extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
91 u8 command);
92extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
3ae70dee 93 u8 command, u16 value);
06a67848
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94
95static inline s32
96i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
97{
98 s32 value = i2c_smbus_read_word_data(client, command);
99
100 return (value < 0) ? value : swab16(value);
101}
102
103static inline s32
104i2c_smbus_write_word_swapped(const struct i2c_client *client,
105 u8 command, u16 value)
106{
107 return i2c_smbus_write_word_data(client, command, swab16(value));
108}
109
b86a1bc8 110/* Returns the number of read bytes */
0cc43a18 111extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
b86a1bc8 112 u8 command, u8 *values);
0cc43a18 113extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
3ae70dee 114 u8 command, u8 length, const u8 *values);
31ec5bc5 115/* Returns the number of read bytes */
0cc43a18 116extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
4b2643d7 117 u8 command, u8 length, u8 *values);
0cc43a18 118extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
21bbd691 119 u8 command, u8 length,
46f5ed75 120 const u8 *values);
23af8400 121#endif /* I2C */
1da177e4 122
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123/**
124 * struct i2c_driver - represent an I2C device driver
125 * @class: What kind of i2c device we instantiate (for detect)
fe6fc258
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126 * @attach_adapter: Callback for bus addition (deprecated)
127 * @detach_adapter: Callback for bus removal (deprecated)
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128 * @probe: Callback for device binding
129 * @remove: Callback for device unbinding
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130 * @shutdown: Callback for device shutdown
131 * @suspend: Callback for device suspend
132 * @resume: Callback for device resume
72d2e9f9 133 * @alert: Alert callback, for example for the SMBus alert protocol
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JD
134 * @command: Callback for bus-wide signaling (optional)
135 * @driver: Device driver model driver
136 * @id_table: List of I2C devices supported by this driver
4735c98f 137 * @detect: Callback for device detection
c3813d6a 138 * @address_list: The I2C addresses to probe (for detect)
4735c98f 139 * @clients: List of detected clients we created (for i2c-core use only)
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LR
140 *
141 * The driver.owner field should be set to the module owner of this driver.
142 * The driver.name field should be set to the name of this driver.
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143 *
144 * For automatic device detection, both @detect and @address_data must
145 * be defined. @class should also be set, otherwise only devices forced
146 * with module parameters will be created. The detect function must
147 * fill at least the name field of the i2c_board_info structure it is
148 * handed upon successful detection, and possibly also the flags field.
149 *
150 * If @detect is missing, the driver will still work fine for enumerated
151 * devices. Detected devices simply won't be supported. This is expected
152 * for the many I2C/SMBus devices which can't be detected reliably, and
153 * the ones which can always be enumerated in practice.
154 *
155 * The i2c_client structure which is handed to the @detect callback is
156 * not a real i2c_client. It is initialized just enough so that you can
157 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
158 * else with it. In particular, calling dev_dbg and friends on it is
159 * not allowed.
1da177e4 160 */
1da177e4 161struct i2c_driver {
1da177e4 162 unsigned int class;
1da177e4 163
729d6dd5 164 /* Notifies the driver that a new bus has appeared or is about to be
fe6fc258
JD
165 * removed. You should avoid using this, it will be removed in a
166 * near future.
1da177e4 167 */
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168 int (*attach_adapter)(struct i2c_adapter *) __deprecated;
169 int (*detach_adapter)(struct i2c_adapter *) __deprecated;
1da177e4 170
729d6dd5 171 /* Standard driver model interfaces */
d2653e92 172 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
a1d9e6e4 173 int (*remove)(struct i2c_client *);
7b4fbc50 174
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DB
175 /* driver model interfaces that don't relate to enumeration */
176 void (*shutdown)(struct i2c_client *);
177 int (*suspend)(struct i2c_client *, pm_message_t mesg);
178 int (*resume)(struct i2c_client *);
179
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JD
180 /* Alert callback, for example for the SMBus alert protocol.
181 * The format and meaning of the data value depends on the protocol.
182 * For the SMBus alert protocol, there is a single bit of data passed
183 * as the alert response's low bit ("event flag").
184 */
185 void (*alert)(struct i2c_client *, unsigned int data);
186
1da177e4
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187 /* a ioctl like command that can be used to perform specific functions
188 * with the device.
189 */
3ae70dee 190 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
1da177e4
LT
191
192 struct device_driver driver;
d2653e92 193 const struct i2c_device_id *id_table;
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194
195 /* Device detection callback for automatic device creation */
310ec792 196 int (*detect)(struct i2c_client *, struct i2c_board_info *);
c3813d6a 197 const unsigned short *address_list;
4735c98f 198 struct list_head clients;
1da177e4
LT
199};
200#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
201
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DB
202/**
203 * struct i2c_client - represent an I2C slave device
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DB
204 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
205 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
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DB
206 * @addr: Address used on the I2C bus connected to the parent adapter.
207 * @name: Indicates the type of the device, usually a chip name that's
208 * generic enough to hide second-sourcing and compatible revisions.
d64f73be 209 * @adapter: manages the bus segment hosting this I2C device
aa3481d5 210 * @driver: device's driver, hence pointer to access routines
2096b956 211 * @dev: Driver model device node for the slave.
d64f73be 212 * @irq: indicates the IRQ generated by this device (if any)
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213 * @detected: member of an i2c_driver.clients list or i2c-core's
214 * userspace_devices list
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DB
215 *
216 * An i2c_client identifies a single device (i.e. chip) connected to an
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DB
217 * i2c bus. The behaviour exposed to Linux is defined by the driver
218 * managing the device.
1da177e4
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219 */
220struct i2c_client {
2096b956 221 unsigned short flags; /* div., see below */
438d6c2c 222 unsigned short addr; /* chip address - NOTE: 7bit */
1da177e4 223 /* addresses are stored in the */
5071860a 224 /* _LOWER_ 7 bits */
2096b956 225 char name[I2C_NAME_SIZE];
1da177e4
LT
226 struct i2c_adapter *adapter; /* the adapter we sit on */
227 struct i2c_driver *driver; /* and our access routines */
1da177e4 228 struct device dev; /* the device structure */
8e29da9e 229 int irq; /* irq issued by device */
4735c98f 230 struct list_head detected;
1da177e4
LT
231};
232#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
233
9b766b81 234extern struct i2c_client *i2c_verify_client(struct device *dev);
643dd09e 235extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
9b766b81 236
a61fc683 237static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
238{
d75d53cd
MH
239 struct device * const dev = container_of(kobj, struct device, kobj);
240 return to_i2c_client(dev);
a61fc683 241}
242
7d1d8999 243static inline void *i2c_get_clientdata(const struct i2c_client *dev)
1da177e4 244{
3ae70dee 245 return dev_get_drvdata(&dev->dev);
1da177e4
LT
246}
247
3ae70dee 248static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
1da177e4 249{
3ae70dee 250 dev_set_drvdata(&dev->dev, data);
1da177e4
LT
251}
252
9c1600ed
DB
253/**
254 * struct i2c_board_info - template for device creation
eb8a7908 255 * @type: chip type, to initialize i2c_client.name
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DB
256 * @flags: to initialize i2c_client.flags
257 * @addr: stored in i2c_client.addr
258 * @platform_data: stored in i2c_client.dev.platform_data
11f1f2af 259 * @archdata: copied into i2c_client.dev.archdata
72d2e9f9 260 * @of_node: pointer to OpenFirmware device node
9c1600ed 261 * @irq: stored in i2c_client.irq
d64f73be 262 *
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DB
263 * I2C doesn't actually support hardware probing, although controllers and
264 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
265 * a device at a given address. Drivers commonly need more information than
266 * that, such as chip type, configuration, associated IRQ, and so on.
267 *
268 * i2c_board_info is used to build tables of information listing I2C devices
729d6dd5
JD
269 * that are present. This information is used to grow the driver model tree.
270 * For mainboards this is done statically using i2c_register_board_info();
271 * bus numbers identify adapters that aren't yet available. For add-on boards,
272 * i2c_new_device() does this dynamically with the adapter already known.
9c1600ed
DB
273 */
274struct i2c_board_info {
9c1600ed
DB
275 char type[I2C_NAME_SIZE];
276 unsigned short flags;
277 unsigned short addr;
278 void *platform_data;
11f1f2af 279 struct dev_archdata *archdata;
d12d42f7 280 struct device_node *of_node;
9c1600ed
DB
281 int irq;
282};
283
284/**
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285 * I2C_BOARD_INFO - macro used to list an i2c device and its address
286 * @dev_type: identifies the device type
9c1600ed
DB
287 * @dev_addr: the device's address on the bus.
288 *
289 * This macro initializes essential fields of a struct i2c_board_info,
290 * declaring what has been provided on a particular board. Optional
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JD
291 * fields (such as associated irq, or device-specific platform_data)
292 * are provided using conventional syntax.
9c1600ed 293 */
3ae70dee 294#define I2C_BOARD_INFO(dev_type, dev_addr) \
c758e8cf 295 .type = dev_type, .addr = (dev_addr)
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DB
296
297
23af8400 298#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
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DB
299/* Add-on boards should register/unregister their devices; e.g. a board
300 * with integrated I2C, a config eeprom, sensors, and a codec that's
301 * used in conjunction with the primary hardware.
302 */
303extern struct i2c_client *
304i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
305
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306/* If you don't know the exact address of an I2C device, use this variant
307 * instead, which can probe for device presence in a list of possible
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308 * addresses. The "probe" callback function is optional. If it is provided,
309 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
310 * a default probing method is used.
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JD
311 */
312extern struct i2c_client *
313i2c_new_probed_device(struct i2c_adapter *adap,
314 struct i2c_board_info *info,
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315 unsigned short const *addr_list,
316 int (*probe)(struct i2c_adapter *, unsigned short addr));
12b5053a 317
d44f19d5
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318/* Common custom probe functions */
319extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
320
e9f1373b
DB
321/* For devices that use several addresses, use i2c_new_dummy() to make
322 * client handles for the extra addresses.
323 */
324extern struct i2c_client *
60b129d7 325i2c_new_dummy(struct i2c_adapter *adap, u16 address);
e9f1373b 326
9c1600ed 327extern void i2c_unregister_device(struct i2c_client *);
23af8400 328#endif /* I2C */
9c1600ed
DB
329
330/* Mainboard arch_initcall() code should register all its I2C devices.
331 * This is done at arch_initcall time, before declaring any i2c adapters.
332 * Modules for add-on boards must use other calls.
333 */
26386763 334#ifdef CONFIG_I2C_BOARDINFO
9c1600ed 335extern int
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JD
336i2c_register_board_info(int busnum, struct i2c_board_info const *info,
337 unsigned n);
26386763
DB
338#else
339static inline int
3ae70dee
JD
340i2c_register_board_info(int busnum, struct i2c_board_info const *info,
341 unsigned n)
26386763
DB
342{
343 return 0;
344}
23af8400 345#endif /* I2C_BOARDINFO */
9c1600ed 346
1da177e4
LT
347/*
348 * The following structs are for those who like to implement new bus drivers:
349 * i2c_algorithm is the interface to a class of hardware solutions which can
350 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
351 * to name two of the most common.
352 */
353struct i2c_algorithm {
1da177e4 354 /* If an adapter algorithm can't do I2C-level access, set master_xfer
438d6c2c 355 to NULL. If an adapter algorithm can do SMBus access, set
1da177e4
LT
356 smbus_xfer. If set to NULL, the SMBus protocol is simulated
357 using common I2C messages */
8ced8eee
JD
358 /* master_xfer should return the number of messages successfully
359 processed, or a negative value on error */
3ae70dee
JD
360 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
361 int num);
438d6c2c 362 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
3ae70dee
JD
363 unsigned short flags, char read_write,
364 u8 command, int size, union i2c_smbus_data *data);
1da177e4 365
1da177e4
LT
366 /* To determine what the adapter supports */
367 u32 (*functionality) (struct i2c_adapter *);
368};
369
370/*
371 * i2c_adapter is the structure used to identify a physical i2c bus along
372 * with the access algorithms necessary to access it.
373 */
374struct i2c_adapter {
375 struct module *owner;
14f55f7a 376 unsigned int class; /* classes to allow probing for */
af71ff69 377 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
1da177e4
LT
378 void *algo_data;
379
1da177e4 380 /* data fields that are valid for all devices */
194684e5 381 struct rt_mutex bus_lock;
1da177e4 382
cd97f39b 383 int timeout; /* in jiffies */
1da177e4
LT
384 int retries;
385 struct device dev; /* the adapter device */
1da177e4 386
1da177e4 387 int nr;
2096b956 388 char name[48];
1da177e4 389 struct completion dev_released;
6629dcff 390
dafc50d1 391 struct mutex userspace_clients_lock;
6629dcff 392 struct list_head userspace_clients;
1da177e4 393};
ef2c8321 394#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
1da177e4 395
7d1d8999 396static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
1da177e4 397{
3ae70dee 398 return dev_get_drvdata(&dev->dev);
1da177e4
LT
399}
400
3ae70dee 401static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
1da177e4 402{
3ae70dee 403 dev_set_drvdata(&dev->dev, data);
1da177e4
LT
404}
405
97cc4d49
JD
406static inline struct i2c_adapter *
407i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
0826374b 408{
97cc4d49
JD
409 struct device *parent = adapter->dev.parent;
410
411 if (parent != NULL && parent->type == &i2c_adapter_type)
412 return to_i2c_adapter(parent);
413 else
414 return NULL;
0826374b
ML
415}
416
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417int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
418
fe61e07e
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419/* Adapter locking functions, exported for shared pin cases */
420void i2c_lock_adapter(struct i2c_adapter *);
421void i2c_unlock_adapter(struct i2c_adapter *);
afa08974 422
1da177e4 423/*flags for the client struct: */
3bbb835d
DB
424#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
425#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
426 /* Must equal I2C_M_TEN below */
427#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
1da177e4
LT
428
429/* i2c adapter classes (bitmask) */
430#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
c1b6b4f2 431#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
774466ad 432#define I2C_CLASS_SPD (1<<7) /* Memory modules */
1da177e4 433
1da177e4
LT
434/* Internal numbers to terminate lists */
435#define I2C_CLIENT_END 0xfffeU
1da177e4 436
c7036673
HV
437/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
438#define I2C_ADDRS(addr, addrs...) \
439 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
440
1da177e4
LT
441
442/* ----- functions exported by i2c.o */
443
444/* administration...
445 */
23af8400 446#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
1da177e4
LT
447extern int i2c_add_adapter(struct i2c_adapter *);
448extern int i2c_del_adapter(struct i2c_adapter *);
6e13e641 449extern int i2c_add_numbered_adapter(struct i2c_adapter *);
1da177e4 450
de59cf9e 451extern int i2c_register_driver(struct module *, struct i2c_driver *);
b3e82096 452extern void i2c_del_driver(struct i2c_driver *);
1da177e4 453
eb5589a8
PG
454/* use a define to avoid include chaining to get THIS_MODULE */
455#define i2c_add_driver(driver) \
456 i2c_register_driver(THIS_MODULE, driver)
de59cf9e 457
e48d3319
JD
458extern struct i2c_client *i2c_use_client(struct i2c_client *client);
459extern void i2c_release_client(struct i2c_client *client);
1da177e4
LT
460
461/* call the i2c_client->command() of all attached clients with
462 * the given arguments */
463extern void i2c_clients_command(struct i2c_adapter *adap,
464 unsigned int cmd, void *arg);
465
d735b34d 466extern struct i2c_adapter *i2c_get_adapter(int nr);
1da177e4
LT
467extern void i2c_put_adapter(struct i2c_adapter *adap);
468
469
470/* Return the functionality mask */
471static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
472{
473 return adap->algo->functionality(adap);
474}
475
476/* Return 1 if adapter supports everything we need, 0 if not. */
477static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
478{
479 return (func & i2c_get_functionality(adap)) == func;
480}
481
3ae70dee 482/* Return the adapter number for a specific adapter */
cdcb1921
JD
483static inline int i2c_adapter_id(struct i2c_adapter *adap)
484{
485 return adap->nr;
486}
7c92784a
LPC
487
488/**
489 * module_i2c_driver() - Helper macro for registering a I2C driver
490 * @__i2c_driver: i2c_driver struct
491 *
492 * Helper macro for I2C drivers which do not do anything special in module
493 * init/exit. This eliminates a lot of boilerplate. Each module may only
494 * use this macro once, and calling it replaces module_init() and module_exit()
495 */
496#define module_i2c_driver(__i2c_driver) \
497 module_driver(__i2c_driver, i2c_add_driver, \
498 i2c_del_driver)
499
23af8400 500#endif /* I2C */
a1b9298e 501#endif /* __KERNEL__ */
cdcb1921 502
a64ec07d
DB
503/**
504 * struct i2c_msg - an I2C transaction segment beginning with START
505 * @addr: Slave address, either seven or ten bits. When this is a ten
506 * bit address, I2C_M_TEN must be set in @flags and the adapter
507 * must support I2C_FUNC_10BIT_ADDR.
508 * @flags: I2C_M_RD is handled by all adapters. No other flags may be
509 * provided unless the adapter exported the relevant I2C_FUNC_*
510 * flags through i2c_check_functionality().
511 * @len: Number of data bytes in @buf being read from or written to the
512 * I2C slave address. For read transactions where I2C_M_RECV_LEN
513 * is set, the caller guarantees that this buffer can hold up to
514 * 32 bytes in addition to the initial length byte sent by the
515 * slave (plus, if used, the SMBus PEC); and this value will be
516 * incremented by the number of block data bytes received.
517 * @buf: The buffer into which data is read, or from which it's written.
518 *
519 * An i2c_msg is the low level representation of one segment of an I2C
520 * transaction. It is visible to drivers in the @i2c_transfer() procedure,
521 * to userspace from i2c-dev, and to I2C adapter drivers through the
522 * @i2c_adapter.@master_xfer() method.
523 *
524 * Except when I2C "protocol mangling" is used, all I2C adapters implement
525 * the standard rules for I2C transactions. Each transaction begins with a
526 * START. That is followed by the slave address, and a bit encoding read
527 * versus write. Then follow all the data bytes, possibly including a byte
528 * with SMBus PEC. The transfer terminates with a NAK, or when all those
529 * bytes have been transferred and ACKed. If this is the last message in a
530 * group, it is followed by a STOP. Otherwise it is followed by the next
531 * @i2c_msg transaction segment, beginning with a (repeated) START.
532 *
533 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
534 * passing certain @flags may have changed those standard protocol behaviors.
535 * Those flags are only for use with broken/nonconforming slaves, and with
536 * adapters which are known to support the specific mangling options they
537 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
1da177e4
LT
538 */
539struct i2c_msg {
540 __u16 addr; /* slave address */
438d6c2c 541 __u16 flags;
a64ec07d
DB
542#define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
543#define I2C_M_RD 0x0001 /* read data, from slave to master */
14674e70 544#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_NOSTART */
a64ec07d
DB
545#define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
546#define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
547#define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
548#define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
438d6c2c
DB
549 __u16 len; /* msg length */
550 __u8 *buf; /* pointer to msg data */
1da177e4
LT
551};
552
553/* To determine what functionality is present */
554
555#define I2C_FUNC_I2C 0x00000001
556#define I2C_FUNC_10BIT_ADDR 0x00000002
14674e70 557#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_IGNORE_NAK etc. */
6662cbb9 558#define I2C_FUNC_SMBUS_PEC 0x00000008
14674e70 559#define I2C_FUNC_NOSTART 0x00000010 /* I2C_M_NOSTART */
1da177e4 560#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
438d6c2c
DB
561#define I2C_FUNC_SMBUS_QUICK 0x00010000
562#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
563#define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
564#define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
565#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
566#define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
567#define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
568#define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
569#define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
570#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
1da177e4
LT
571#define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */
572#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */
1da177e4 573
3ae70dee
JD
574#define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
575 I2C_FUNC_SMBUS_WRITE_BYTE)
576#define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
577 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
578#define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
579 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
580#define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
581 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
582#define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
583 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
584
585#define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
586 I2C_FUNC_SMBUS_BYTE | \
587 I2C_FUNC_SMBUS_BYTE_DATA | \
588 I2C_FUNC_SMBUS_WORD_DATA | \
589 I2C_FUNC_SMBUS_PROC_CALL | \
590 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
591 I2C_FUNC_SMBUS_I2C_BLOCK | \
592 I2C_FUNC_SMBUS_PEC)
1da177e4 593
438d6c2c
DB
594/*
595 * Data for SMBus Messages
1da177e4 596 */
438d6c2c 597#define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
1da177e4
LT
598union i2c_smbus_data {
599 __u8 byte;
600 __u16 word;
332bf92b 601 __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
3ae70dee 602 /* and one more for user-space compatibility */
1da177e4
LT
603};
604
ae7193f7 605/* i2c_smbus_xfer read or write markers */
1da177e4
LT
606#define I2C_SMBUS_READ 1
607#define I2C_SMBUS_WRITE 0
608
438d6c2c 609/* SMBus transaction types (size parameter in the above functions)
1da177e4
LT
610 Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
611#define I2C_SMBUS_QUICK 0
612#define I2C_SMBUS_BYTE 1
438d6c2c 613#define I2C_SMBUS_BYTE_DATA 2
1da177e4
LT
614#define I2C_SMBUS_WORD_DATA 3
615#define I2C_SMBUS_PROC_CALL 4
616#define I2C_SMBUS_BLOCK_DATA 5
4b2643d7 617#define I2C_SMBUS_I2C_BLOCK_BROKEN 6
1da177e4 618#define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
4b2643d7 619#define I2C_SMBUS_I2C_BLOCK_DATA 8
1da177e4 620
1da177e4 621#endif /* _LINUX_I2C_H */