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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__
David Woodhousea1b92982006-04-25 14:14:52 +010031#include <linux/module.h>
Greg Kroah-Hartmana9d1b242005-10-22 00:23:27 +020032#include <linux/mod_devicetable.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/device.h> /* for struct device */
Tim Schmielau4e57b682005-10-30 15:03:48 -080034#include <linux/sched.h> /* for completion */
Ingo Molnar5c085d32006-01-18 23:16:04 +010035#include <linux/mutex.h>
Grant Likelyd12d42f2010-04-13 16:12:28 -070036#include <linux/of.h> /* for struct device_node */
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
Jean Delvare23af8402009-06-19 16:58:20 +020051#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052/*
53 * The master routines are the ones normally used to transmit data to devices
David Brownell438d6c22006-12-10 21:21:31 +010054 * on a bus (or read from them). Apart from two basic transfer functions to
55 * transmit one message at a time, a more complex version can be used to
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 * transmit an arbitrary number of messages without interruption.
Zhangfei Gao0c43ea52010-03-02 12:23:49 +010057 * @count must be be less than 64k since msg.len is u16.
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 */
Jean Delvare0cc43a12011-01-10 22:11:23 +010059extern int i2c_master_send(const struct i2c_client *client, const char *buf,
Jean Delvare3ae70de2008-10-22 20:21:32 +020060 int count);
Jean Delvare0cc43a12011-01-10 22:11:23 +010061extern int i2c_master_recv(const struct i2c_client *client, char *buf,
62 int count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64/* Transfer num messages.
65 */
Jean Delvare3ae70de2008-10-22 20:21:32 +020066extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
67 int num);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69/* This is the very generalized SMBus access routine. You probably do not
70 want to use this, though; one of the functions below may be much easier,
David Brownell438d6c22006-12-10 21:21:31 +010071 and probably just as fast.
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 Note that we use i2c_adapter here, because you do not need a specific
73 smbus adapter to call this function. */
Jean Delvare3ae70de2008-10-22 20:21:32 +020074extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
75 unsigned short flags, char read_write, u8 command,
76 int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78/* Now follow the 'nice' access routines. These also document the calling
Jean Delvareae7193f2008-07-14 22:38:24 +020079 conventions of i2c_smbus_xfer. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Jean Delvare0cc43a12011-01-10 22:11:23 +010081extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
82extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
83extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
84 u8 command);
85extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020086 u8 command, u8 value);
Jean Delvare0cc43a12011-01-10 22:11:23 +010087extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
88 u8 command);
89extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020090 u8 command, u16 value);
Jean Delvareb86a1bc2007-05-01 23:26:34 +020091/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +010092extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
Jean Delvareb86a1bc2007-05-01 23:26:34 +020093 u8 command, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +010094extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020095 u8 command, u8 length, const u8 *values);
Jean Delvare31ec5bc2005-10-08 00:04:13 +020096/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +010097extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
Jean Delvare4b2643d2007-07-12 14:12:29 +020098 u8 command, u8 length, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +010099extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
Jean Delvare21bbd692006-01-09 15:19:18 +1100100 u8 command, u8 length,
Krzysztof Halasa46f5ed72006-06-12 21:42:20 +0200101 const u8 *values);
Jean Delvare23af8402009-06-19 16:58:20 +0200102#endif /* I2C */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Jean Delvare4735c982008-07-14 22:38:36 +0200104/**
105 * struct i2c_driver - represent an I2C device driver
106 * @class: What kind of i2c device we instantiate (for detect)
Jean Delvarefe6fc252011-03-20 14:50:53 +0100107 * @attach_adapter: Callback for bus addition (deprecated)
108 * @detach_adapter: Callback for bus removal (deprecated)
Jean Delvare729d6dd2009-06-19 16:58:18 +0200109 * @probe: Callback for device binding
110 * @remove: Callback for device unbinding
Jean Delvare96e21e42008-08-28 08:33:23 +0200111 * @shutdown: Callback for device shutdown
112 * @suspend: Callback for device suspend
113 * @resume: Callback for device resume
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700114 * @alert: Alert callback, for example for the SMBus alert protocol
Jean Delvare96e21e42008-08-28 08:33:23 +0200115 * @command: Callback for bus-wide signaling (optional)
116 * @driver: Device driver model driver
117 * @id_table: List of I2C devices supported by this driver
Jean Delvare4735c982008-07-14 22:38:36 +0200118 * @detect: Callback for device detection
Jean Delvarec3813d62009-12-14 21:17:25 +0100119 * @address_list: The I2C addresses to probe (for detect)
Jean Delvare4735c982008-07-14 22:38:36 +0200120 * @clients: List of detected clients we created (for i2c-core use only)
Laurent Riffard35d8b2e2005-11-26 20:34:05 +0100121 *
122 * The driver.owner field should be set to the module owner of this driver.
123 * The driver.name field should be set to the name of this driver.
Jean Delvare4735c982008-07-14 22:38:36 +0200124 *
125 * For automatic device detection, both @detect and @address_data must
126 * be defined. @class should also be set, otherwise only devices forced
127 * with module parameters will be created. The detect function must
128 * fill at least the name field of the i2c_board_info structure it is
129 * handed upon successful detection, and possibly also the flags field.
130 *
131 * If @detect is missing, the driver will still work fine for enumerated
132 * devices. Detected devices simply won't be supported. This is expected
133 * for the many I2C/SMBus devices which can't be detected reliably, and
134 * the ones which can always be enumerated in practice.
135 *
136 * The i2c_client structure which is handed to the @detect callback is
137 * not a real i2c_client. It is initialized just enough so that you can
138 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
139 * else with it. In particular, calling dev_dbg and friends on it is
140 * not allowed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142struct i2c_driver {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 unsigned int class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Jean Delvare729d6dd2009-06-19 16:58:18 +0200145 /* Notifies the driver that a new bus has appeared or is about to be
Jean Delvarefe6fc252011-03-20 14:50:53 +0100146 * removed. You should avoid using this, it will be removed in a
147 * near future.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 */
Jean Delvarefe6fc252011-03-20 14:50:53 +0100149 int (*attach_adapter)(struct i2c_adapter *) __deprecated;
150 int (*detach_adapter)(struct i2c_adapter *) __deprecated;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Jean Delvare729d6dd2009-06-19 16:58:18 +0200152 /* Standard driver model interfaces */
Jean Delvared2653e92008-04-29 23:11:39 +0200153 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
David Brownella1d9e6e2007-05-01 23:26:30 +0200154 int (*remove)(struct i2c_client *);
David Brownell7b4fbc52007-05-01 23:26:30 +0200155
David Brownellf37dd802007-02-13 22:09:00 +0100156 /* driver model interfaces that don't relate to enumeration */
157 void (*shutdown)(struct i2c_client *);
158 int (*suspend)(struct i2c_client *, pm_message_t mesg);
159 int (*resume)(struct i2c_client *);
160
Jean Delvareb5527a72010-03-02 12:23:42 +0100161 /* Alert callback, for example for the SMBus alert protocol.
162 * The format and meaning of the data value depends on the protocol.
163 * For the SMBus alert protocol, there is a single bit of data passed
164 * as the alert response's low bit ("event flag").
165 */
166 void (*alert)(struct i2c_client *, unsigned int data);
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 /* a ioctl like command that can be used to perform specific functions
169 * with the device.
170 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200171 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
173 struct device_driver driver;
Jean Delvared2653e92008-04-29 23:11:39 +0200174 const struct i2c_device_id *id_table;
Jean Delvare4735c982008-07-14 22:38:36 +0200175
176 /* Device detection callback for automatic device creation */
Jean Delvare310ec792009-12-14 21:17:23 +0100177 int (*detect)(struct i2c_client *, struct i2c_board_info *);
Jean Delvarec3813d62009-12-14 21:17:25 +0100178 const unsigned short *address_list;
Jean Delvare4735c982008-07-14 22:38:36 +0200179 struct list_head clients;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180};
181#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
182
David Brownell2096b952007-05-01 23:26:28 +0200183/**
184 * struct i2c_client - represent an I2C slave device
David Brownelld64f73b2007-07-12 14:12:28 +0200185 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
186 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
David Brownell2096b952007-05-01 23:26:28 +0200187 * @addr: Address used on the I2C bus connected to the parent adapter.
188 * @name: Indicates the type of the device, usually a chip name that's
189 * generic enough to hide second-sourcing and compatible revisions.
David Brownelld64f73b2007-07-12 14:12:28 +0200190 * @adapter: manages the bus segment hosting this I2C device
Randy Dunlapaa3481d2007-07-31 00:39:02 -0700191 * @driver: device's driver, hence pointer to access routines
David Brownell2096b952007-05-01 23:26:28 +0200192 * @dev: Driver model device node for the slave.
David Brownelld64f73b2007-07-12 14:12:28 +0200193 * @irq: indicates the IRQ generated by this device (if any)
Jean Delvare99cd8e22009-06-19 16:58:20 +0200194 * @detected: member of an i2c_driver.clients list or i2c-core's
195 * userspace_devices list
David Brownell2096b952007-05-01 23:26:28 +0200196 *
197 * An i2c_client identifies a single device (i.e. chip) connected to an
David Brownelld64f73b2007-07-12 14:12:28 +0200198 * i2c bus. The behaviour exposed to Linux is defined by the driver
199 * managing the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 */
201struct i2c_client {
David Brownell2096b952007-05-01 23:26:28 +0200202 unsigned short flags; /* div., see below */
David Brownell438d6c22006-12-10 21:21:31 +0100203 unsigned short addr; /* chip address - NOTE: 7bit */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 /* addresses are stored in the */
Jean Delvare50718602005-07-20 00:02:32 +0200205 /* _LOWER_ 7 bits */
David Brownell2096b952007-05-01 23:26:28 +0200206 char name[I2C_NAME_SIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 struct i2c_adapter *adapter; /* the adapter we sit on */
208 struct i2c_driver *driver; /* and our access routines */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 struct device dev; /* the device structure */
Wolfram Sang8e29da92008-07-01 22:38:18 +0200210 int irq; /* irq issued by device */
Jean Delvare4735c982008-07-14 22:38:36 +0200211 struct list_head detected;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212};
213#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
214
David Brownell9b766b82008-01-27 18:14:51 +0100215extern struct i2c_client *i2c_verify_client(struct device *dev);
216
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500217static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
218{
Mark M. Hoffmand75d53c2007-07-12 14:12:28 +0200219 struct device * const dev = container_of(kobj, struct device, kobj);
220 return to_i2c_client(dev);
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500221}
222
Jean Delvare7d1d8992008-10-22 20:21:31 +0200223static inline void *i2c_get_clientdata(const struct i2c_client *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200225 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226}
227
Jean Delvare3ae70de2008-10-22 20:21:32 +0200228static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200230 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231}
232
David Brownell9c1600e2007-05-01 23:26:31 +0200233/**
234 * struct i2c_board_info - template for device creation
Jean Delvareeb8a7902008-05-18 20:49:41 +0200235 * @type: chip type, to initialize i2c_client.name
David Brownell9c1600e2007-05-01 23:26:31 +0200236 * @flags: to initialize i2c_client.flags
237 * @addr: stored in i2c_client.addr
238 * @platform_data: stored in i2c_client.dev.platform_data
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200239 * @archdata: copied into i2c_client.dev.archdata
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700240 * @of_node: pointer to OpenFirmware device node
David Brownell9c1600e2007-05-01 23:26:31 +0200241 * @irq: stored in i2c_client.irq
David Brownelld64f73b2007-07-12 14:12:28 +0200242 *
David Brownell9c1600e2007-05-01 23:26:31 +0200243 * I2C doesn't actually support hardware probing, although controllers and
244 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
245 * a device at a given address. Drivers commonly need more information than
246 * that, such as chip type, configuration, associated IRQ, and so on.
247 *
248 * i2c_board_info is used to build tables of information listing I2C devices
Jean Delvare729d6dd2009-06-19 16:58:18 +0200249 * that are present. This information is used to grow the driver model tree.
250 * For mainboards this is done statically using i2c_register_board_info();
251 * bus numbers identify adapters that aren't yet available. For add-on boards,
252 * i2c_new_device() does this dynamically with the adapter already known.
David Brownell9c1600e2007-05-01 23:26:31 +0200253 */
254struct i2c_board_info {
David Brownell9c1600e2007-05-01 23:26:31 +0200255 char type[I2C_NAME_SIZE];
256 unsigned short flags;
257 unsigned short addr;
258 void *platform_data;
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200259 struct dev_archdata *archdata;
Grant Likelyd12d42f2010-04-13 16:12:28 -0700260 struct device_node *of_node;
David Brownell9c1600e2007-05-01 23:26:31 +0200261 int irq;
262};
263
264/**
Jean Delvare3760f732008-04-29 23:11:40 +0200265 * I2C_BOARD_INFO - macro used to list an i2c device and its address
266 * @dev_type: identifies the device type
David Brownell9c1600e2007-05-01 23:26:31 +0200267 * @dev_addr: the device's address on the bus.
268 *
269 * This macro initializes essential fields of a struct i2c_board_info,
270 * declaring what has been provided on a particular board. Optional
Jean Delvare3760f732008-04-29 23:11:40 +0200271 * fields (such as associated irq, or device-specific platform_data)
272 * are provided using conventional syntax.
David Brownell9c1600e2007-05-01 23:26:31 +0200273 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200274#define I2C_BOARD_INFO(dev_type, dev_addr) \
Ben Hutchingsc758e8c2009-04-13 17:02:14 +0200275 .type = dev_type, .addr = (dev_addr)
David Brownell9c1600e2007-05-01 23:26:31 +0200276
277
Jean Delvare23af8402009-06-19 16:58:20 +0200278#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
David Brownell9c1600e2007-05-01 23:26:31 +0200279/* Add-on boards should register/unregister their devices; e.g. a board
280 * with integrated I2C, a config eeprom, sensors, and a codec that's
281 * used in conjunction with the primary hardware.
282 */
283extern struct i2c_client *
284i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
285
Jean Delvare12b5053a2007-05-01 23:26:31 +0200286/* If you don't know the exact address of an I2C device, use this variant
287 * instead, which can probe for device presence in a list of possible
Jean Delvare9a942412010-08-11 18:20:56 +0200288 * addresses. The "probe" callback function is optional. If it is provided,
289 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
290 * a default probing method is used.
Jean Delvare12b5053a2007-05-01 23:26:31 +0200291 */
292extern struct i2c_client *
293i2c_new_probed_device(struct i2c_adapter *adap,
294 struct i2c_board_info *info,
Jean Delvare9a942412010-08-11 18:20:56 +0200295 unsigned short const *addr_list,
296 int (*probe)(struct i2c_adapter *, unsigned short addr));
Jean Delvare12b5053a2007-05-01 23:26:31 +0200297
Jean Delvared44f19d2010-08-11 18:20:57 +0200298/* Common custom probe functions */
299extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
300
David Brownelle9f13732008-01-27 18:14:52 +0100301/* For devices that use several addresses, use i2c_new_dummy() to make
302 * client handles for the extra addresses.
303 */
304extern struct i2c_client *
Jean Delvare60b129d2008-05-11 20:37:06 +0200305i2c_new_dummy(struct i2c_adapter *adap, u16 address);
David Brownelle9f13732008-01-27 18:14:52 +0100306
David Brownell9c1600e2007-05-01 23:26:31 +0200307extern void i2c_unregister_device(struct i2c_client *);
Jean Delvare23af8402009-06-19 16:58:20 +0200308#endif /* I2C */
David Brownell9c1600e2007-05-01 23:26:31 +0200309
310/* Mainboard arch_initcall() code should register all its I2C devices.
311 * This is done at arch_initcall time, before declaring any i2c adapters.
312 * Modules for add-on boards must use other calls.
313 */
David Brownell26386762008-02-24 20:03:42 +0100314#ifdef CONFIG_I2C_BOARDINFO
David Brownell9c1600e2007-05-01 23:26:31 +0200315extern int
Jean Delvare3ae70de2008-10-22 20:21:32 +0200316i2c_register_board_info(int busnum, struct i2c_board_info const *info,
317 unsigned n);
David Brownell26386762008-02-24 20:03:42 +0100318#else
319static inline int
Jean Delvare3ae70de2008-10-22 20:21:32 +0200320i2c_register_board_info(int busnum, struct i2c_board_info const *info,
321 unsigned n)
David Brownell26386762008-02-24 20:03:42 +0100322{
323 return 0;
324}
Jean Delvare23af8402009-06-19 16:58:20 +0200325#endif /* I2C_BOARDINFO */
David Brownell9c1600e2007-05-01 23:26:31 +0200326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327/*
328 * The following structs are for those who like to implement new bus drivers:
329 * i2c_algorithm is the interface to a class of hardware solutions which can
330 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
331 * to name two of the most common.
332 */
333struct i2c_algorithm {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 /* If an adapter algorithm can't do I2C-level access, set master_xfer
David Brownell438d6c22006-12-10 21:21:31 +0100335 to NULL. If an adapter algorithm can do SMBus access, set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 smbus_xfer. If set to NULL, the SMBus protocol is simulated
337 using common I2C messages */
Jean Delvare8ced8ee2006-07-01 17:12:53 +0200338 /* master_xfer should return the number of messages successfully
339 processed, or a negative value on error */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200340 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
341 int num);
David Brownell438d6c22006-12-10 21:21:31 +0100342 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200343 unsigned short flags, char read_write,
344 u8 command, int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 /* To determine what the adapter supports */
347 u32 (*functionality) (struct i2c_adapter *);
348};
349
350/*
351 * i2c_adapter is the structure used to identify a physical i2c bus along
352 * with the access algorithms necessary to access it.
353 */
354struct i2c_adapter {
355 struct module *owner;
Wolfram Sang14f55f72008-10-22 20:21:30 +0200356 unsigned int class; /* classes to allow probing for */
David Brownellaf71ff62006-09-03 22:37:11 +0200357 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 void *algo_data;
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 /* data fields that are valid for all devices */
Mika Kuoppala194684e2009-12-06 17:06:22 +0100361 struct rt_mutex bus_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
Jean Delvarecd97f392009-02-24 19:19:49 +0100363 int timeout; /* in jiffies */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 int retries;
365 struct device dev; /* the adapter device */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 int nr;
David Brownell2096b952007-05-01 23:26:28 +0200368 char name[48];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 struct completion dev_released;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200370
Jean Delvaredafc50d2010-08-11 18:21:01 +0200371 struct mutex userspace_clients_lock;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200372 struct list_head userspace_clients;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373};
David Brownellef2c83212007-05-01 23:26:28 +0200374#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Jean Delvare7d1d8992008-10-22 20:21:31 +0200376static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200378 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379}
380
Jean Delvare3ae70de2008-10-22 20:21:32 +0200381static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200383 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384}
385
Jean Delvare97cc4d42010-10-24 18:16:57 +0200386static inline struct i2c_adapter *
387i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
Michael Lawnick08263742010-08-11 18:21:02 +0200388{
Jean Delvare97cc4d42010-10-24 18:16:57 +0200389 struct device *parent = adapter->dev.parent;
390
391 if (parent != NULL && parent->type == &i2c_adapter_type)
392 return to_i2c_adapter(parent);
393 else
394 return NULL;
Michael Lawnick08263742010-08-11 18:21:02 +0200395}
396
Jean Delvare7ae31482011-03-20 14:50:52 +0100397int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
398
Jean Delvarefe61e072010-08-11 18:20:58 +0200399/* Adapter locking functions, exported for shared pin cases */
400void i2c_lock_adapter(struct i2c_adapter *);
401void i2c_unlock_adapter(struct i2c_adapter *);
Jean Delvareafa08972009-11-07 13:10:46 +0100402
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403/*flags for the client struct: */
David Brownell3bbb8352007-10-13 23:56:29 +0200404#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
405#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
406 /* Must equal I2C_M_TEN below */
407#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408
409/* i2c adapter classes (bitmask) */
410#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
Jean Delvarec1b6b4f2008-07-14 22:38:28 +0200411#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
Jean Delvare774466a2011-05-25 20:43:32 +0200412#define I2C_CLASS_SPD (1<<7) /* Memory modules */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414/* Internal numbers to terminate lists */
415#define I2C_CLIENT_END 0xfffeU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
417/* The numbers to use to set I2C bus address */
418#define ANY_I2C_BUS 0xffff
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
Hans Verkuilc7036672009-06-19 16:58:21 +0200420/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
421#define I2C_ADDRS(addr, addrs...) \
422 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
423
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
425/* ----- functions exported by i2c.o */
426
427/* administration...
428 */
Jean Delvare23af8402009-06-19 16:58:20 +0200429#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430extern int i2c_add_adapter(struct i2c_adapter *);
431extern int i2c_del_adapter(struct i2c_adapter *);
David Brownell6e13e642007-05-01 23:26:31 +0200432extern int i2c_add_numbered_adapter(struct i2c_adapter *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800434extern int i2c_register_driver(struct module *, struct i2c_driver *);
Jean Delvareb3e82092007-05-01 23:26:32 +0200435extern void i2c_del_driver(struct i2c_driver *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800437static inline int i2c_add_driver(struct i2c_driver *driver)
438{
439 return i2c_register_driver(THIS_MODULE, driver);
440}
441
Jean Delvaree48d3312008-01-27 18:14:48 +0100442extern struct i2c_client *i2c_use_client(struct i2c_client *client);
443extern void i2c_release_client(struct i2c_client *client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
445/* call the i2c_client->command() of all attached clients with
446 * the given arguments */
447extern void i2c_clients_command(struct i2c_adapter *adap,
448 unsigned int cmd, void *arg);
449
Jean Delvared735b342011-03-20 14:50:52 +0100450extern struct i2c_adapter *i2c_get_adapter(int nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451extern void i2c_put_adapter(struct i2c_adapter *adap);
452
453
454/* Return the functionality mask */
455static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
456{
457 return adap->algo->functionality(adap);
458}
459
460/* Return 1 if adapter supports everything we need, 0 if not. */
461static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
462{
463 return (func & i2c_get_functionality(adap)) == func;
464}
465
Jean Delvare3ae70de2008-10-22 20:21:32 +0200466/* Return the adapter number for a specific adapter */
Jean Delvarecdcb1922005-07-28 23:09:40 +0200467static inline int i2c_adapter_id(struct i2c_adapter *adap)
468{
469 return adap->nr;
470}
Jean Delvare23af8402009-06-19 16:58:20 +0200471#endif /* I2C */
David Woodhousea1b92982006-04-25 14:14:52 +0100472#endif /* __KERNEL__ */
Jean Delvarecdcb1922005-07-28 23:09:40 +0200473
David Brownella64ec072007-10-13 23:56:31 +0200474/**
475 * struct i2c_msg - an I2C transaction segment beginning with START
476 * @addr: Slave address, either seven or ten bits. When this is a ten
477 * bit address, I2C_M_TEN must be set in @flags and the adapter
478 * must support I2C_FUNC_10BIT_ADDR.
479 * @flags: I2C_M_RD is handled by all adapters. No other flags may be
480 * provided unless the adapter exported the relevant I2C_FUNC_*
481 * flags through i2c_check_functionality().
482 * @len: Number of data bytes in @buf being read from or written to the
483 * I2C slave address. For read transactions where I2C_M_RECV_LEN
484 * is set, the caller guarantees that this buffer can hold up to
485 * 32 bytes in addition to the initial length byte sent by the
486 * slave (plus, if used, the SMBus PEC); and this value will be
487 * incremented by the number of block data bytes received.
488 * @buf: The buffer into which data is read, or from which it's written.
489 *
490 * An i2c_msg is the low level representation of one segment of an I2C
491 * transaction. It is visible to drivers in the @i2c_transfer() procedure,
492 * to userspace from i2c-dev, and to I2C adapter drivers through the
493 * @i2c_adapter.@master_xfer() method.
494 *
495 * Except when I2C "protocol mangling" is used, all I2C adapters implement
496 * the standard rules for I2C transactions. Each transaction begins with a
497 * START. That is followed by the slave address, and a bit encoding read
498 * versus write. Then follow all the data bytes, possibly including a byte
499 * with SMBus PEC. The transfer terminates with a NAK, or when all those
500 * bytes have been transferred and ACKed. If this is the last message in a
501 * group, it is followed by a STOP. Otherwise it is followed by the next
502 * @i2c_msg transaction segment, beginning with a (repeated) START.
503 *
504 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
505 * passing certain @flags may have changed those standard protocol behaviors.
506 * Those flags are only for use with broken/nonconforming slaves, and with
507 * adapters which are known to support the specific mangling options they
508 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 */
510struct i2c_msg {
511 __u16 addr; /* slave address */
David Brownell438d6c22006-12-10 21:21:31 +0100512 __u16 flags;
David Brownella64ec072007-10-13 23:56:31 +0200513#define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
514#define I2C_M_RD 0x0001 /* read data, from slave to master */
515#define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */
516#define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
517#define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
518#define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
519#define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
David Brownell438d6c22006-12-10 21:21:31 +0100520 __u16 len; /* msg length */
521 __u8 *buf; /* pointer to msg data */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522};
523
524/* To determine what functionality is present */
525
526#define I2C_FUNC_I2C 0x00000001
527#define I2C_FUNC_10BIT_ADDR 0x00000002
Jean Delvare3ae70de2008-10-22 20:21:32 +0200528#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */
David Brownell6662cbb2007-10-13 23:56:33 +0200529#define I2C_FUNC_SMBUS_PEC 0x00000008
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
David Brownell438d6c22006-12-10 21:21:31 +0100531#define I2C_FUNC_SMBUS_QUICK 0x00010000
532#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
533#define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
534#define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
535#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
536#define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
537#define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
538#define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
539#define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
540#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541#define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */
542#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
Jean Delvare3ae70de2008-10-22 20:21:32 +0200544#define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
545 I2C_FUNC_SMBUS_WRITE_BYTE)
546#define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
547 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
548#define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
549 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
550#define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
551 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
552#define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
553 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
Jean Delvare3ae70de2008-10-22 20:21:32 +0200555#define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
556 I2C_FUNC_SMBUS_BYTE | \
557 I2C_FUNC_SMBUS_BYTE_DATA | \
558 I2C_FUNC_SMBUS_WORD_DATA | \
559 I2C_FUNC_SMBUS_PROC_CALL | \
560 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
561 I2C_FUNC_SMBUS_I2C_BLOCK | \
562 I2C_FUNC_SMBUS_PEC)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
David Brownell438d6c22006-12-10 21:21:31 +0100564/*
565 * Data for SMBus Messages
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 */
David Brownell438d6c22006-12-10 21:21:31 +0100567#define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568union i2c_smbus_data {
569 __u8 byte;
570 __u16 word;
Hideki Iwamoto332bf922005-09-25 16:56:43 +0200571 __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200572 /* and one more for user-space compatibility */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573};
574
Jean Delvareae7193f2008-07-14 22:38:24 +0200575/* i2c_smbus_xfer read or write markers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576#define I2C_SMBUS_READ 1
577#define I2C_SMBUS_WRITE 0
578
David Brownell438d6c22006-12-10 21:21:31 +0100579/* SMBus transaction types (size parameter in the above functions)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
581#define I2C_SMBUS_QUICK 0
582#define I2C_SMBUS_BYTE 1
David Brownell438d6c22006-12-10 21:21:31 +0100583#define I2C_SMBUS_BYTE_DATA 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584#define I2C_SMBUS_WORD_DATA 3
585#define I2C_SMBUS_PROC_CALL 4
586#define I2C_SMBUS_BLOCK_DATA 5
Jean Delvare4b2643d2007-07-12 14:12:29 +0200587#define I2C_SMBUS_I2C_BLOCK_BROKEN 6
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588#define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
Jean Delvare4b2643d2007-07-12 14:12:29 +0200589#define I2C_SMBUS_I2C_BLOCK_DATA 8
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591#endif /* _LINUX_I2C_H */