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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* ------------------------------------------------------------------------- */
David Brownell438d6c22006-12-10 21:21:31 +01002/* */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003/* i2c.h - definitions for the i2c-bus interface */
David Brownell438d6c22006-12-10 21:21:31 +01004/* */
Linus Torvalds1da177e2005-04-16 15:20:36 -07005/* ------------------------------------------------------------------------- */
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
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
21/* ------------------------------------------------------------------------- */
22
David Woodhousea1b92982006-04-25 14:14:52 +010023/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 Frodo Looijaard <frodol@dds.nl> */
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#ifndef _LINUX_I2C_H
27#define _LINUX_I2C_H
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/types.h>
David Brownell438d6c22006-12-10 21:21:31 +010030#ifdef __KERNEL__
Greg Kroah-Hartmana9d1b242005-10-22 00:23:27 +020031#include <linux/mod_devicetable.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/device.h> /* for struct device */
Tim Schmielau4e57b682005-10-30 15:03:48 -080033#include <linux/sched.h> /* for completion */
Ingo Molnar5c085d32006-01-18 23:16:04 +010034#include <linux/mutex.h>
Grant Likelyd12d42f2010-04-13 16:12:28 -070035#include <linux/of.h> /* for struct device_node */
Jonathan Cameron06a67842011-10-30 13:47:25 +010036#include <linux/swab.h> /* for swab16 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Jon Smirle9ca9eb2008-07-14 22:38:35 +020038extern struct bus_type i2c_bus_type;
Michael Lawnick08263742010-08-11 18:21:02 +020039extern struct device_type i2c_adapter_type;
Jon Smirle9ca9eb2008-07-14 22:38:35 +020040
Linus Torvalds1da177e2005-04-16 15:20:36 -070041/* --- General options ------------------------------------------------ */
42
43struct i2c_msg;
44struct i2c_algorithm;
45struct i2c_adapter;
46struct i2c_client;
47struct i2c_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048union i2c_smbus_data;
Jean Delvare4735c982008-07-14 22:38:36 +020049struct i2c_board_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Paul Gortmakerde477252011-05-26 13:46:22 -040051struct module;
52
Jean Delvare23af8402009-06-19 16:58:20 +020053#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054/*
55 * The master routines are the ones normally used to transmit data to devices
David Brownell438d6c22006-12-10 21:21:31 +010056 * on a bus (or read from them). Apart from two basic transfer functions to
57 * transmit one message at a time, a more complex version can be used to
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 * transmit an arbitrary number of messages without interruption.
Zhangfei Gao0c43ea52010-03-02 12:23:49 +010059 * @count must be be less than 64k since msg.len is u16.
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 */
Jean Delvare0cc43a12011-01-10 22:11:23 +010061extern int i2c_master_send(const struct i2c_client *client, const char *buf,
Jean Delvare3ae70de2008-10-22 20:21:32 +020062 int count);
Jean Delvare0cc43a12011-01-10 22:11:23 +010063extern int i2c_master_recv(const struct i2c_client *client, char *buf,
64 int count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66/* Transfer num messages.
67 */
Jean Delvare3ae70de2008-10-22 20:21:32 +020068extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
69 int num);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
71/* This is the very generalized SMBus access routine. You probably do not
72 want to use this, though; one of the functions below may be much easier,
David Brownell438d6c22006-12-10 21:21:31 +010073 and probably just as fast.
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 Note that we use i2c_adapter here, because you do not need a specific
75 smbus adapter to call this function. */
Jean Delvare3ae70de2008-10-22 20:21:32 +020076extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
77 unsigned short flags, char read_write, u8 command,
78 int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80/* Now follow the 'nice' access routines. These also document the calling
Jean Delvareae7193f2008-07-14 22:38:24 +020081 conventions of i2c_smbus_xfer. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Jean Delvare0cc43a12011-01-10 22:11:23 +010083extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
84extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
85extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
86 u8 command);
87extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020088 u8 command, u8 value);
Jean Delvare0cc43a12011-01-10 22:11:23 +010089extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
90 u8 command);
91extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020092 u8 command, u16 value);
Jonathan Cameron06a67842011-10-30 13:47:25 +010093
94static inline s32
95i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
96{
97 s32 value = i2c_smbus_read_word_data(client, command);
98
99 return (value < 0) ? value : swab16(value);
100}
101
102static inline s32
103i2c_smbus_write_word_swapped(const struct i2c_client *client,
104 u8 command, u16 value)
105{
106 return i2c_smbus_write_word_data(client, command, swab16(value));
107}
108
Jean Delvareb86a1bc2007-05-01 23:26:34 +0200109/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +0100110extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
Jean Delvareb86a1bc2007-05-01 23:26:34 +0200111 u8 command, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +0100112extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200113 u8 command, u8 length, const u8 *values);
Jean Delvare31ec5bc2005-10-08 00:04:13 +0200114/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +0100115extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
Jean Delvare4b2643d2007-07-12 14:12:29 +0200116 u8 command, u8 length, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +0100117extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
Jean Delvare21bbd692006-01-09 15:19:18 +1100118 u8 command, u8 length,
Krzysztof Halasa46f5ed72006-06-12 21:42:20 +0200119 const u8 *values);
Jean Delvare23af8402009-06-19 16:58:20 +0200120#endif /* I2C */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Jean Delvare4735c982008-07-14 22:38:36 +0200122/**
123 * struct i2c_driver - represent an I2C device driver
124 * @class: What kind of i2c device we instantiate (for detect)
Jean Delvarefe6fc252011-03-20 14:50:53 +0100125 * @attach_adapter: Callback for bus addition (deprecated)
126 * @detach_adapter: Callback for bus removal (deprecated)
Jean Delvare729d6dd2009-06-19 16:58:18 +0200127 * @probe: Callback for device binding
128 * @remove: Callback for device unbinding
Jean Delvare96e21e42008-08-28 08:33:23 +0200129 * @shutdown: Callback for device shutdown
130 * @suspend: Callback for device suspend
131 * @resume: Callback for device resume
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700132 * @alert: Alert callback, for example for the SMBus alert protocol
Jean Delvare96e21e42008-08-28 08:33:23 +0200133 * @command: Callback for bus-wide signaling (optional)
134 * @driver: Device driver model driver
135 * @id_table: List of I2C devices supported by this driver
Jean Delvare4735c982008-07-14 22:38:36 +0200136 * @detect: Callback for device detection
Jean Delvarec3813d62009-12-14 21:17:25 +0100137 * @address_list: The I2C addresses to probe (for detect)
Jean Delvare4735c982008-07-14 22:38:36 +0200138 * @clients: List of detected clients we created (for i2c-core use only)
Laurent Riffard35d8b2e2005-11-26 20:34:05 +0100139 *
140 * The driver.owner field should be set to the module owner of this driver.
141 * The driver.name field should be set to the name of this driver.
Jean Delvare4735c982008-07-14 22:38:36 +0200142 *
143 * For automatic device detection, both @detect and @address_data must
144 * be defined. @class should also be set, otherwise only devices forced
145 * with module parameters will be created. The detect function must
146 * fill at least the name field of the i2c_board_info structure it is
147 * handed upon successful detection, and possibly also the flags field.
148 *
149 * If @detect is missing, the driver will still work fine for enumerated
150 * devices. Detected devices simply won't be supported. This is expected
151 * for the many I2C/SMBus devices which can't be detected reliably, and
152 * the ones which can always be enumerated in practice.
153 *
154 * The i2c_client structure which is handed to the @detect callback is
155 * not a real i2c_client. It is initialized just enough so that you can
156 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
157 * else with it. In particular, calling dev_dbg and friends on it is
158 * not allowed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160struct i2c_driver {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 unsigned int class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Jean Delvare729d6dd2009-06-19 16:58:18 +0200163 /* Notifies the driver that a new bus has appeared or is about to be
Jean Delvarefe6fc252011-03-20 14:50:53 +0100164 * removed. You should avoid using this, it will be removed in a
165 * near future.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 */
Jean Delvarefe6fc252011-03-20 14:50:53 +0100167 int (*attach_adapter)(struct i2c_adapter *) __deprecated;
168 int (*detach_adapter)(struct i2c_adapter *) __deprecated;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
Jean Delvare729d6dd2009-06-19 16:58:18 +0200170 /* Standard driver model interfaces */
Jean Delvared2653e92008-04-29 23:11:39 +0200171 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
David Brownella1d9e6e2007-05-01 23:26:30 +0200172 int (*remove)(struct i2c_client *);
David Brownell7b4fbc52007-05-01 23:26:30 +0200173
David Brownellf37dd802007-02-13 22:09:00 +0100174 /* driver model interfaces that don't relate to enumeration */
175 void (*shutdown)(struct i2c_client *);
176 int (*suspend)(struct i2c_client *, pm_message_t mesg);
177 int (*resume)(struct i2c_client *);
178
Jean Delvareb5527a72010-03-02 12:23:42 +0100179 /* Alert callback, for example for the SMBus alert protocol.
180 * The format and meaning of the data value depends on the protocol.
181 * For the SMBus alert protocol, there is a single bit of data passed
182 * as the alert response's low bit ("event flag").
183 */
184 void (*alert)(struct i2c_client *, unsigned int data);
185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 /* a ioctl like command that can be used to perform specific functions
187 * with the device.
188 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200189 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
191 struct device_driver driver;
Jean Delvared2653e92008-04-29 23:11:39 +0200192 const struct i2c_device_id *id_table;
Jean Delvare4735c982008-07-14 22:38:36 +0200193
194 /* Device detection callback for automatic device creation */
Jean Delvare310ec792009-12-14 21:17:23 +0100195 int (*detect)(struct i2c_client *, struct i2c_board_info *);
Jean Delvarec3813d62009-12-14 21:17:25 +0100196 const unsigned short *address_list;
Jean Delvare4735c982008-07-14 22:38:36 +0200197 struct list_head clients;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198};
199#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
200
David Brownell2096b952007-05-01 23:26:28 +0200201/**
202 * struct i2c_client - represent an I2C slave device
David Brownelld64f73b2007-07-12 14:12:28 +0200203 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
204 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
David Brownell2096b952007-05-01 23:26:28 +0200205 * @addr: Address used on the I2C bus connected to the parent adapter.
206 * @name: Indicates the type of the device, usually a chip name that's
207 * generic enough to hide second-sourcing and compatible revisions.
David Brownelld64f73b2007-07-12 14:12:28 +0200208 * @adapter: manages the bus segment hosting this I2C device
Randy Dunlapaa3481d2007-07-31 00:39:02 -0700209 * @driver: device's driver, hence pointer to access routines
David Brownell2096b952007-05-01 23:26:28 +0200210 * @dev: Driver model device node for the slave.
David Brownelld64f73b2007-07-12 14:12:28 +0200211 * @irq: indicates the IRQ generated by this device (if any)
Jean Delvare99cd8e22009-06-19 16:58:20 +0200212 * @detected: member of an i2c_driver.clients list or i2c-core's
213 * userspace_devices list
David Brownell2096b952007-05-01 23:26:28 +0200214 *
215 * An i2c_client identifies a single device (i.e. chip) connected to an
David Brownelld64f73b2007-07-12 14:12:28 +0200216 * i2c bus. The behaviour exposed to Linux is defined by the driver
217 * managing the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 */
219struct i2c_client {
David Brownell2096b952007-05-01 23:26:28 +0200220 unsigned short flags; /* div., see below */
David Brownell438d6c22006-12-10 21:21:31 +0100221 unsigned short addr; /* chip address - NOTE: 7bit */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 /* addresses are stored in the */
Jean Delvare50718602005-07-20 00:02:32 +0200223 /* _LOWER_ 7 bits */
David Brownell2096b952007-05-01 23:26:28 +0200224 char name[I2C_NAME_SIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 struct i2c_adapter *adapter; /* the adapter we sit on */
226 struct i2c_driver *driver; /* and our access routines */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 struct device dev; /* the device structure */
Wolfram Sang8e29da92008-07-01 22:38:18 +0200228 int irq; /* irq issued by device */
Jean Delvare4735c982008-07-14 22:38:36 +0200229 struct list_head detected;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230};
231#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
232
David Brownell9b766b82008-01-27 18:14:51 +0100233extern struct i2c_client *i2c_verify_client(struct device *dev);
234
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500235static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
236{
Mark M. Hoffmand75d53c2007-07-12 14:12:28 +0200237 struct device * const dev = container_of(kobj, struct device, kobj);
238 return to_i2c_client(dev);
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500239}
240
Jean Delvare7d1d8992008-10-22 20:21:31 +0200241static inline void *i2c_get_clientdata(const struct i2c_client *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200243 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244}
245
Jean Delvare3ae70de2008-10-22 20:21:32 +0200246static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200248 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249}
250
David Brownell9c1600e2007-05-01 23:26:31 +0200251/**
252 * struct i2c_board_info - template for device creation
Jean Delvareeb8a7902008-05-18 20:49:41 +0200253 * @type: chip type, to initialize i2c_client.name
David Brownell9c1600e2007-05-01 23:26:31 +0200254 * @flags: to initialize i2c_client.flags
255 * @addr: stored in i2c_client.addr
256 * @platform_data: stored in i2c_client.dev.platform_data
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200257 * @archdata: copied into i2c_client.dev.archdata
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700258 * @of_node: pointer to OpenFirmware device node
David Brownell9c1600e2007-05-01 23:26:31 +0200259 * @irq: stored in i2c_client.irq
David Brownelld64f73b2007-07-12 14:12:28 +0200260 *
David Brownell9c1600e2007-05-01 23:26:31 +0200261 * I2C doesn't actually support hardware probing, although controllers and
262 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
263 * a device at a given address. Drivers commonly need more information than
264 * that, such as chip type, configuration, associated IRQ, and so on.
265 *
266 * i2c_board_info is used to build tables of information listing I2C devices
Jean Delvare729d6dd2009-06-19 16:58:18 +0200267 * that are present. This information is used to grow the driver model tree.
268 * For mainboards this is done statically using i2c_register_board_info();
269 * bus numbers identify adapters that aren't yet available. For add-on boards,
270 * i2c_new_device() does this dynamically with the adapter already known.
David Brownell9c1600e2007-05-01 23:26:31 +0200271 */
272struct i2c_board_info {
David Brownell9c1600e2007-05-01 23:26:31 +0200273 char type[I2C_NAME_SIZE];
274 unsigned short flags;
275 unsigned short addr;
276 void *platform_data;
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200277 struct dev_archdata *archdata;
Grant Likelyd12d42f2010-04-13 16:12:28 -0700278 struct device_node *of_node;
David Brownell9c1600e2007-05-01 23:26:31 +0200279 int irq;
280};
281
282/**
Jean Delvare3760f732008-04-29 23:11:40 +0200283 * I2C_BOARD_INFO - macro used to list an i2c device and its address
284 * @dev_type: identifies the device type
David Brownell9c1600e2007-05-01 23:26:31 +0200285 * @dev_addr: the device's address on the bus.
286 *
287 * This macro initializes essential fields of a struct i2c_board_info,
288 * declaring what has been provided on a particular board. Optional
Jean Delvare3760f732008-04-29 23:11:40 +0200289 * fields (such as associated irq, or device-specific platform_data)
290 * are provided using conventional syntax.
David Brownell9c1600e2007-05-01 23:26:31 +0200291 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200292#define I2C_BOARD_INFO(dev_type, dev_addr) \
Ben Hutchingsc758e8c2009-04-13 17:02:14 +0200293 .type = dev_type, .addr = (dev_addr)
David Brownell9c1600e2007-05-01 23:26:31 +0200294
295
Jean Delvare23af8402009-06-19 16:58:20 +0200296#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
David Brownell9c1600e2007-05-01 23:26:31 +0200297/* Add-on boards should register/unregister their devices; e.g. a board
298 * with integrated I2C, a config eeprom, sensors, and a codec that's
299 * used in conjunction with the primary hardware.
300 */
301extern struct i2c_client *
302i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
303
Jean Delvare12b50532007-05-01 23:26:31 +0200304/* If you don't know the exact address of an I2C device, use this variant
305 * instead, which can probe for device presence in a list of possible
Jean Delvare9a942412010-08-11 18:20:56 +0200306 * addresses. The "probe" callback function is optional. If it is provided,
307 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
308 * a default probing method is used.
Jean Delvare12b50532007-05-01 23:26:31 +0200309 */
310extern struct i2c_client *
311i2c_new_probed_device(struct i2c_adapter *adap,
312 struct i2c_board_info *info,
Jean Delvare9a942412010-08-11 18:20:56 +0200313 unsigned short const *addr_list,
314 int (*probe)(struct i2c_adapter *, unsigned short addr));
Jean Delvare12b50532007-05-01 23:26:31 +0200315
Jean Delvared44f19d2010-08-11 18:20:57 +0200316/* Common custom probe functions */
317extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
318
David Brownelle9f13732008-01-27 18:14:52 +0100319/* For devices that use several addresses, use i2c_new_dummy() to make
320 * client handles for the extra addresses.
321 */
322extern struct i2c_client *
Jean Delvare60b129d2008-05-11 20:37:06 +0200323i2c_new_dummy(struct i2c_adapter *adap, u16 address);
David Brownelle9f13732008-01-27 18:14:52 +0100324
David Brownell9c1600e2007-05-01 23:26:31 +0200325extern void i2c_unregister_device(struct i2c_client *);
Jean Delvare23af8402009-06-19 16:58:20 +0200326#endif /* I2C */
David Brownell9c1600e2007-05-01 23:26:31 +0200327
328/* Mainboard arch_initcall() code should register all its I2C devices.
329 * This is done at arch_initcall time, before declaring any i2c adapters.
330 * Modules for add-on boards must use other calls.
331 */
David Brownell26386762008-02-24 20:03:42 +0100332#ifdef CONFIG_I2C_BOARDINFO
David Brownell9c1600e2007-05-01 23:26:31 +0200333extern int
Jean Delvare3ae70de2008-10-22 20:21:32 +0200334i2c_register_board_info(int busnum, struct i2c_board_info const *info,
335 unsigned n);
David Brownell26386762008-02-24 20:03:42 +0100336#else
337static inline int
Jean Delvare3ae70de2008-10-22 20:21:32 +0200338i2c_register_board_info(int busnum, struct i2c_board_info const *info,
339 unsigned n)
David Brownell26386762008-02-24 20:03:42 +0100340{
341 return 0;
342}
Jean Delvare23af8402009-06-19 16:58:20 +0200343#endif /* I2C_BOARDINFO */
David Brownell9c1600e2007-05-01 23:26:31 +0200344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345/*
346 * The following structs are for those who like to implement new bus drivers:
347 * i2c_algorithm is the interface to a class of hardware solutions which can
348 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
349 * to name two of the most common.
350 */
351struct i2c_algorithm {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 /* If an adapter algorithm can't do I2C-level access, set master_xfer
David Brownell438d6c22006-12-10 21:21:31 +0100353 to NULL. If an adapter algorithm can do SMBus access, set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 smbus_xfer. If set to NULL, the SMBus protocol is simulated
355 using common I2C messages */
Jean Delvare8ced8ee2006-07-01 17:12:53 +0200356 /* master_xfer should return the number of messages successfully
357 processed, or a negative value on error */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200358 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
359 int num);
David Brownell438d6c22006-12-10 21:21:31 +0100360 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200361 unsigned short flags, char read_write,
362 u8 command, int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 /* To determine what the adapter supports */
365 u32 (*functionality) (struct i2c_adapter *);
366};
367
368/*
369 * i2c_adapter is the structure used to identify a physical i2c bus along
370 * with the access algorithms necessary to access it.
371 */
372struct i2c_adapter {
373 struct module *owner;
Wolfram Sang14f55f72008-10-22 20:21:30 +0200374 unsigned int class; /* classes to allow probing for */
David Brownellaf71ff62006-09-03 22:37:11 +0200375 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 void *algo_data;
377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 /* data fields that are valid for all devices */
Mika Kuoppala194684e2009-12-06 17:06:22 +0100379 struct rt_mutex bus_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Jean Delvarecd97f392009-02-24 19:19:49 +0100381 int timeout; /* in jiffies */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 int retries;
383 struct device dev; /* the adapter device */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 int nr;
David Brownell2096b952007-05-01 23:26:28 +0200386 char name[48];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 struct completion dev_released;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200388
Jean Delvaredafc50d2010-08-11 18:21:01 +0200389 struct mutex userspace_clients_lock;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200390 struct list_head userspace_clients;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391};
David Brownellef2c8322007-05-01 23:26:28 +0200392#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
Jean Delvare7d1d8992008-10-22 20:21:31 +0200394static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200396 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397}
398
Jean Delvare3ae70de2008-10-22 20:21:32 +0200399static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200401 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402}
403
Jean Delvare97cc4d42010-10-24 18:16:57 +0200404static inline struct i2c_adapter *
405i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
Michael Lawnick08263742010-08-11 18:21:02 +0200406{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200407 struct device *parent = adapter->dev.parent;
408
409 if (parent != NULL && parent->type == &i2c_adapter_type)
410 return to_i2c_adapter(parent);
411 else
412 return NULL;
Michael Lawnick08263742010-08-11 18:21:02 +0200413}
414
Jean Delvare7ae31482011-03-20 14:50:52 +0100415int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
416
Jean Delvarefe61e072010-08-11 18:20:58 +0200417/* Adapter locking functions, exported for shared pin cases */
418void i2c_lock_adapter(struct i2c_adapter *);
419void i2c_unlock_adapter(struct i2c_adapter *);
Jean Delvareafa08972009-11-07 13:10:46 +0100420
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421/*flags for the client struct: */
David Brownell3bbb8352007-10-13 23:56:29 +0200422#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
423#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
424 /* Must equal I2C_M_TEN below */
425#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427/* i2c adapter classes (bitmask) */
428#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
Jean Delvarec1b6b4f2008-07-14 22:38:28 +0200429#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
Jean Delvare774466a2011-05-25 20:43:32 +0200430#define I2C_CLASS_SPD (1<<7) /* Memory modules */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432/* Internal numbers to terminate lists */
433#define I2C_CLIENT_END 0xfffeU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
Hans Verkuilc7036672009-06-19 16:58:21 +0200435/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
436#define I2C_ADDRS(addr, addrs...) \
437 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
438
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440/* ----- functions exported by i2c.o */
441
442/* administration...
443 */
Jean Delvare23af8402009-06-19 16:58:20 +0200444#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445extern int i2c_add_adapter(struct i2c_adapter *);
446extern int i2c_del_adapter(struct i2c_adapter *);
David Brownell6e13e642007-05-01 23:26:31 +0200447extern int i2c_add_numbered_adapter(struct i2c_adapter *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800449extern int i2c_register_driver(struct module *, struct i2c_driver *);
Jean Delvareb3e82092007-05-01 23:26:32 +0200450extern void i2c_del_driver(struct i2c_driver *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451
Paul Gortmakereb5589a2011-05-27 09:02:11 -0400452/* use a define to avoid include chaining to get THIS_MODULE */
453#define i2c_add_driver(driver) \
454 i2c_register_driver(THIS_MODULE, driver)
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800455
Jean Delvaree48d3312008-01-27 18:14:48 +0100456extern struct i2c_client *i2c_use_client(struct i2c_client *client);
457extern void i2c_release_client(struct i2c_client *client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458
459/* call the i2c_client->command() of all attached clients with
460 * the given arguments */
461extern void i2c_clients_command(struct i2c_adapter *adap,
462 unsigned int cmd, void *arg);
463
Jean Delvared735b342011-03-20 14:50:52 +0100464extern struct i2c_adapter *i2c_get_adapter(int nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465extern void i2c_put_adapter(struct i2c_adapter *adap);
466
467
468/* Return the functionality mask */
469static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
470{
471 return adap->algo->functionality(adap);
472}
473
474/* Return 1 if adapter supports everything we need, 0 if not. */
475static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
476{
477 return (func & i2c_get_functionality(adap)) == func;
478}
479
Jean Delvare3ae70de2008-10-22 20:21:32 +0200480/* Return the adapter number for a specific adapter */
Jean Delvarecdcb1922005-07-28 23:09:40 +0200481static inline int i2c_adapter_id(struct i2c_adapter *adap)
482{
483 return adap->nr;
484}
Lars-Peter Clausen7c927842011-11-16 10:13:36 +0100485
486/**
487 * module_i2c_driver() - Helper macro for registering a I2C driver
488 * @__i2c_driver: i2c_driver struct
489 *
490 * Helper macro for I2C drivers which do not do anything special in module
491 * init/exit. This eliminates a lot of boilerplate. Each module may only
492 * use this macro once, and calling it replaces module_init() and module_exit()
493 */
494#define module_i2c_driver(__i2c_driver) \
495 module_driver(__i2c_driver, i2c_add_driver, \
496 i2c_del_driver)
497
Jean Delvare23af8402009-06-19 16:58:20 +0200498#endif /* I2C */
David Woodhousea1b92982006-04-25 14:14:52 +0100499#endif /* __KERNEL__ */
Jean Delvarecdcb1922005-07-28 23:09:40 +0200500
David Brownella64ec072007-10-13 23:56:31 +0200501/**
502 * struct i2c_msg - an I2C transaction segment beginning with START
503 * @addr: Slave address, either seven or ten bits. When this is a ten
504 * bit address, I2C_M_TEN must be set in @flags and the adapter
505 * must support I2C_FUNC_10BIT_ADDR.
506 * @flags: I2C_M_RD is handled by all adapters. No other flags may be
507 * provided unless the adapter exported the relevant I2C_FUNC_*
508 * flags through i2c_check_functionality().
509 * @len: Number of data bytes in @buf being read from or written to the
510 * I2C slave address. For read transactions where I2C_M_RECV_LEN
511 * is set, the caller guarantees that this buffer can hold up to
512 * 32 bytes in addition to the initial length byte sent by the
513 * slave (plus, if used, the SMBus PEC); and this value will be
514 * incremented by the number of block data bytes received.
515 * @buf: The buffer into which data is read, or from which it's written.
516 *
517 * An i2c_msg is the low level representation of one segment of an I2C
518 * transaction. It is visible to drivers in the @i2c_transfer() procedure,
519 * to userspace from i2c-dev, and to I2C adapter drivers through the
520 * @i2c_adapter.@master_xfer() method.
521 *
522 * Except when I2C "protocol mangling" is used, all I2C adapters implement
523 * the standard rules for I2C transactions. Each transaction begins with a
524 * START. That is followed by the slave address, and a bit encoding read
525 * versus write. Then follow all the data bytes, possibly including a byte
526 * with SMBus PEC. The transfer terminates with a NAK, or when all those
527 * bytes have been transferred and ACKed. If this is the last message in a
528 * group, it is followed by a STOP. Otherwise it is followed by the next
529 * @i2c_msg transaction segment, beginning with a (repeated) START.
530 *
531 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
532 * passing certain @flags may have changed those standard protocol behaviors.
533 * Those flags are only for use with broken/nonconforming slaves, and with
534 * adapters which are known to support the specific mangling options they
535 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 */
537struct i2c_msg {
538 __u16 addr; /* slave address */
David Brownell438d6c22006-12-10 21:21:31 +0100539 __u16 flags;
David Brownella64ec072007-10-13 23:56:31 +0200540#define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
541#define I2C_M_RD 0x0001 /* read data, from slave to master */
542#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */
543#define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
544#define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
545#define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
546#define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
David Brownell438d6c22006-12-10 21:21:31 +0100547 __u16 len; /* msg length */
548 __u8 *buf; /* pointer to msg data */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549};
550
551/* To determine what functionality is present */
552
553#define I2C_FUNC_I2C 0x00000001
554#define I2C_FUNC_10BIT_ADDR 0x00000002
Jean Delvare3ae70de2008-10-22 20:21:32 +0200555#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */
David Brownell6662cbb2007-10-13 23:56:33 +0200556#define I2C_FUNC_SMBUS_PEC 0x00000008
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
David Brownell438d6c22006-12-10 21:21:31 +0100558#define I2C_FUNC_SMBUS_QUICK 0x00010000
559#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
560#define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
561#define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
562#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
563#define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
564#define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
565#define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
566#define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
567#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568#define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */
569#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570
Jean Delvare3ae70de2008-10-22 20:21:32 +0200571#define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
572 I2C_FUNC_SMBUS_WRITE_BYTE)
573#define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
574 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
575#define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
576 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
577#define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
578 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
579#define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
580 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581
Jean Delvare3ae70de2008-10-22 20:21:32 +0200582#define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
583 I2C_FUNC_SMBUS_BYTE | \
584 I2C_FUNC_SMBUS_BYTE_DATA | \
585 I2C_FUNC_SMBUS_WORD_DATA | \
586 I2C_FUNC_SMBUS_PROC_CALL | \
587 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
588 I2C_FUNC_SMBUS_I2C_BLOCK | \
589 I2C_FUNC_SMBUS_PEC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
David Brownell438d6c22006-12-10 21:21:31 +0100591/*
592 * Data for SMBus Messages
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 */
David Brownell438d6c22006-12-10 21:21:31 +0100594#define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595union i2c_smbus_data {
596 __u8 byte;
597 __u16 word;
Hideki Iwamoto332bf922005-09-25 16:56:43 +0200598 __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200599 /* and one more for user-space compatibility */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600};
601
Jean Delvareae7193f2008-07-14 22:38:24 +0200602/* i2c_smbus_xfer read or write markers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603#define I2C_SMBUS_READ 1
604#define I2C_SMBUS_WRITE 0
605
David Brownell438d6c22006-12-10 21:21:31 +0100606/* SMBus transaction types (size parameter in the above functions)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
608#define I2C_SMBUS_QUICK 0
609#define I2C_SMBUS_BYTE 1
David Brownell438d6c22006-12-10 21:21:31 +0100610#define I2C_SMBUS_BYTE_DATA 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611#define I2C_SMBUS_WORD_DATA 3
612#define I2C_SMBUS_PROC_CALL 4
613#define I2C_SMBUS_BLOCK_DATA 5
Jean Delvare4b2643d2007-07-12 14:12:29 +0200614#define I2C_SMBUS_I2C_BLOCK_BROKEN 6
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615#define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
Jean Delvare4b2643d2007-07-12 14:12:29 +0200616#define I2C_SMBUS_I2C_BLOCK_DATA 8
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618#endif /* _LINUX_I2C_H */