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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
Jean Delvare5694f8a2012-03-26 21:47:19 +020020 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
21 MA 02110-1301 USA. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070022/* ------------------------------------------------------------------------- */
23
David Woodhousea1b92982006-04-25 14:14:52 +010024/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 Frodo Looijaard <frodol@dds.nl> */
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#ifndef _LINUX_I2C_H
27#define _LINUX_I2C_H
28
Greg Kroah-Hartmana9d1b242005-10-22 00:23:27 +020029#include <linux/mod_devicetable.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/device.h> /* for struct device */
Tim Schmielau4e57b682005-10-30 15:03:48 -080031#include <linux/sched.h> /* for completion */
Ingo Molnar5c085d32006-01-18 23:16:04 +010032#include <linux/mutex.h>
Grant Likelyd12d42f2010-04-13 16:12:28 -070033#include <linux/of.h> /* for struct device_node */
Jonathan Cameron06a67842011-10-30 13:47:25 +010034#include <linux/swab.h> /* for swab16 */
David Howells607ca462012-10-13 10:46:48 +010035#include <uapi/linux/i2c.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Jon Smirle9ca9eb2008-07-14 22:38:35 +020037extern struct bus_type i2c_bus_type;
Michael Lawnick08263742010-08-11 18:21:02 +020038extern struct device_type i2c_adapter_type;
Jon Smirle9ca9eb2008-07-14 22:38:35 +020039
Linus Torvalds1da177e2005-04-16 15:20:36 -070040/* --- General options ------------------------------------------------ */
41
42struct i2c_msg;
43struct i2c_algorithm;
44struct i2c_adapter;
45struct i2c_client;
46struct i2c_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047union i2c_smbus_data;
Jean Delvare4735c982008-07-14 22:38:36 +020048struct i2c_board_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Paul Gortmakerde477252011-05-26 13:46:22 -040050struct module;
51
Jean Delvare23af8402009-06-19 16:58:20 +020052#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053/*
54 * The master routines are the ones normally used to transmit data to devices
David Brownell438d6c22006-12-10 21:21:31 +010055 * on a bus (or read from them). Apart from two basic transfer functions to
56 * transmit one message at a time, a more complex version can be used to
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 * transmit an arbitrary number of messages without interruption.
Zhangfei Gao0c43ea52010-03-02 12:23:49 +010058 * @count must be be less than 64k since msg.len is u16.
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 */
Jean Delvare0cc43a12011-01-10 22:11:23 +010060extern int i2c_master_send(const struct i2c_client *client, const char *buf,
Jean Delvare3ae70de2008-10-22 20:21:32 +020061 int count);
Jean Delvare0cc43a12011-01-10 22:11:23 +010062extern int i2c_master_recv(const struct i2c_client *client, char *buf,
63 int count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65/* Transfer num messages.
66 */
Jean Delvare3ae70de2008-10-22 20:21:32 +020067extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
68 int num);
Jean Delvareb37d2a32012-06-29 07:47:19 -030069/* Unlocked flavor */
70extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
71 int num);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73/* This is the very generalized SMBus access routine. You probably do not
74 want to use this, though; one of the functions below may be much easier,
David Brownell438d6c22006-12-10 21:21:31 +010075 and probably just as fast.
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 Note that we use i2c_adapter here, because you do not need a specific
77 smbus adapter to call this function. */
Jean Delvare3ae70de2008-10-22 20:21:32 +020078extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
79 unsigned short flags, char read_write, u8 command,
80 int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82/* Now follow the 'nice' access routines. These also document the calling
Jean Delvareae7193f2008-07-14 22:38:24 +020083 conventions of i2c_smbus_xfer. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Jean Delvare0cc43a12011-01-10 22:11:23 +010085extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
86extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
87extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
88 u8 command);
89extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020090 u8 command, u8 value);
Jean Delvare0cc43a12011-01-10 22:11:23 +010091extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
92 u8 command);
93extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020094 u8 command, u16 value);
Jonathan Cameron06a67842011-10-30 13:47:25 +010095
96static inline s32
97i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
98{
99 s32 value = i2c_smbus_read_word_data(client, command);
100
101 return (value < 0) ? value : swab16(value);
102}
103
104static inline s32
105i2c_smbus_write_word_swapped(const struct i2c_client *client,
106 u8 command, u16 value)
107{
108 return i2c_smbus_write_word_data(client, command, swab16(value));
109}
110
Jean Delvareb86a1bc2007-05-01 23:26:34 +0200111/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +0100112extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
Jean Delvareb86a1bc2007-05-01 23:26:34 +0200113 u8 command, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +0100114extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200115 u8 command, u8 length, const u8 *values);
Jean Delvare31ec5bc2005-10-08 00:04:13 +0200116/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +0100117extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
Jean Delvare4b2643d2007-07-12 14:12:29 +0200118 u8 command, u8 length, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +0100119extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
Jean Delvare21bbd692006-01-09 15:19:18 +1100120 u8 command, u8 length,
Krzysztof Halasa46f5ed72006-06-12 21:42:20 +0200121 const u8 *values);
Jean Delvare23af8402009-06-19 16:58:20 +0200122#endif /* I2C */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Jean Delvare4735c982008-07-14 22:38:36 +0200124/**
125 * struct i2c_driver - represent an I2C device driver
126 * @class: What kind of i2c device we instantiate (for detect)
Jean Delvarefe6fc252011-03-20 14:50:53 +0100127 * @attach_adapter: Callback for bus addition (deprecated)
Jean Delvare729d6dd2009-06-19 16:58:18 +0200128 * @probe: Callback for device binding
129 * @remove: Callback for device unbinding
Jean Delvare96e21e42008-08-28 08:33:23 +0200130 * @shutdown: Callback for device shutdown
131 * @suspend: Callback for device suspend
132 * @resume: Callback for device resume
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700133 * @alert: Alert callback, for example for the SMBus alert protocol
Jean Delvare96e21e42008-08-28 08:33:23 +0200134 * @command: Callback for bus-wide signaling (optional)
135 * @driver: Device driver model driver
136 * @id_table: List of I2C devices supported by this driver
Jean Delvare4735c982008-07-14 22:38:36 +0200137 * @detect: Callback for device detection
Jean Delvarec3813d62009-12-14 21:17:25 +0100138 * @address_list: The I2C addresses to probe (for detect)
Jean Delvare4735c982008-07-14 22:38:36 +0200139 * @clients: List of detected clients we created (for i2c-core use only)
Laurent Riffard35d8b2e2005-11-26 20:34:05 +0100140 *
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.
Jean Delvare4735c982008-07-14 22:38:36 +0200143 *
Vivien Didelot0ec13862012-10-05 22:23:54 +0200144 * For automatic device detection, both @detect and @address_list must
Jean Delvare4735c982008-07-14 22:38:36 +0200145 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161struct i2c_driver {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 unsigned int class;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Lars-Peter Clausen19baba42013-03-09 08:16:44 +0000164 /* Notifies the driver that a new bus has appeared. You should avoid
165 * using this, it will be removed in a 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Jean Delvare729d6dd2009-06-19 16:58:18 +0200169 /* Standard driver model interfaces */
Jean Delvared2653e92008-04-29 23:11:39 +0200170 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
David Brownella1d9e6e2007-05-01 23:26:30 +0200171 int (*remove)(struct i2c_client *);
David Brownell7b4fbc52007-05-01 23:26:30 +0200172
David Brownellf37dd802007-02-13 22:09:00 +0100173 /* driver model interfaces that don't relate to enumeration */
174 void (*shutdown)(struct i2c_client *);
175 int (*suspend)(struct i2c_client *, pm_message_t mesg);
176 int (*resume)(struct i2c_client *);
177
Jean Delvareb5527a72010-03-02 12:23:42 +0100178 /* Alert callback, for example for the SMBus alert protocol.
179 * The format and meaning of the data value depends on the protocol.
180 * For the SMBus alert protocol, there is a single bit of data passed
181 * as the alert response's low bit ("event flag").
182 */
183 void (*alert)(struct i2c_client *, unsigned int data);
184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 /* a ioctl like command that can be used to perform specific functions
186 * with the device.
187 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200188 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 struct device_driver driver;
Jean Delvared2653e92008-04-29 23:11:39 +0200191 const struct i2c_device_id *id_table;
Jean Delvare4735c982008-07-14 22:38:36 +0200192
193 /* Device detection callback for automatic device creation */
Jean Delvare310ec792009-12-14 21:17:23 +0100194 int (*detect)(struct i2c_client *, struct i2c_board_info *);
Jean Delvarec3813d62009-12-14 21:17:25 +0100195 const unsigned short *address_list;
Jean Delvare4735c982008-07-14 22:38:36 +0200196 struct list_head clients;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197};
198#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
199
David Brownell2096b952007-05-01 23:26:28 +0200200/**
201 * struct i2c_client - represent an I2C slave device
David Brownelld64f73b2007-07-12 14:12:28 +0200202 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
203 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
David Brownell2096b952007-05-01 23:26:28 +0200204 * @addr: Address used on the I2C bus connected to the parent adapter.
205 * @name: Indicates the type of the device, usually a chip name that's
206 * generic enough to hide second-sourcing and compatible revisions.
David Brownelld64f73b2007-07-12 14:12:28 +0200207 * @adapter: manages the bus segment hosting this I2C device
David Brownell2096b952007-05-01 23:26:28 +0200208 * @dev: Driver model device node for the slave.
David Brownelld64f73b2007-07-12 14:12:28 +0200209 * @irq: indicates the IRQ generated by this device (if any)
Jean Delvare99cd8e22009-06-19 16:58:20 +0200210 * @detected: member of an i2c_driver.clients list or i2c-core's
211 * userspace_devices list
David Brownell2096b952007-05-01 23:26:28 +0200212 *
213 * An i2c_client identifies a single device (i.e. chip) connected to an
David Brownelld64f73b2007-07-12 14:12:28 +0200214 * i2c bus. The behaviour exposed to Linux is defined by the driver
215 * managing the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 */
217struct i2c_client {
David Brownell2096b952007-05-01 23:26:28 +0200218 unsigned short flags; /* div., see below */
David Brownell438d6c22006-12-10 21:21:31 +0100219 unsigned short addr; /* chip address - NOTE: 7bit */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 /* addresses are stored in the */
Jean Delvare50718602005-07-20 00:02:32 +0200221 /* _LOWER_ 7 bits */
David Brownell2096b952007-05-01 23:26:28 +0200222 char name[I2C_NAME_SIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 struct i2c_adapter *adapter; /* the adapter we sit on */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 struct device dev; /* the device structure */
Wolfram Sang8e29da92008-07-01 22:38:18 +0200225 int irq; /* irq issued by device */
Jean Delvare4735c982008-07-14 22:38:36 +0200226 struct list_head detected;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227};
228#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
229
David Brownell9b766b82008-01-27 18:14:51 +0100230extern struct i2c_client *i2c_verify_client(struct device *dev);
Stephen Warren643dd092012-04-17 12:43:33 -0600231extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
David Brownell9b766b82008-01-27 18:14:51 +0100232
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500233static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
234{
Mark M. Hoffmand75d53c2007-07-12 14:12:28 +0200235 struct device * const dev = container_of(kobj, struct device, kobj);
236 return to_i2c_client(dev);
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500237}
238
Jean Delvare7d1d8992008-10-22 20:21:31 +0200239static inline void *i2c_get_clientdata(const struct i2c_client *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200241 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
Jean Delvare3ae70de2008-10-22 20:21:32 +0200244static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200246 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247}
248
David Brownell9c1600e2007-05-01 23:26:31 +0200249/**
250 * struct i2c_board_info - template for device creation
Jean Delvareeb8a7902008-05-18 20:49:41 +0200251 * @type: chip type, to initialize i2c_client.name
David Brownell9c1600e2007-05-01 23:26:31 +0200252 * @flags: to initialize i2c_client.flags
253 * @addr: stored in i2c_client.addr
254 * @platform_data: stored in i2c_client.dev.platform_data
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200255 * @archdata: copied into i2c_client.dev.archdata
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700256 * @of_node: pointer to OpenFirmware device node
Mika Westerberg907ddf82012-11-23 12:23:40 +0100257 * @acpi_node: ACPI device node
David Brownell9c1600e2007-05-01 23:26:31 +0200258 * @irq: stored in i2c_client.irq
David Brownelld64f73b2007-07-12 14:12:28 +0200259 *
David Brownell9c1600e2007-05-01 23:26:31 +0200260 * I2C doesn't actually support hardware probing, although controllers and
261 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
262 * a device at a given address. Drivers commonly need more information than
263 * that, such as chip type, configuration, associated IRQ, and so on.
264 *
265 * i2c_board_info is used to build tables of information listing I2C devices
Jean Delvare729d6dd2009-06-19 16:58:18 +0200266 * that are present. This information is used to grow the driver model tree.
267 * For mainboards this is done statically using i2c_register_board_info();
268 * bus numbers identify adapters that aren't yet available. For add-on boards,
269 * i2c_new_device() does this dynamically with the adapter already known.
David Brownell9c1600e2007-05-01 23:26:31 +0200270 */
271struct i2c_board_info {
David Brownell9c1600e2007-05-01 23:26:31 +0200272 char type[I2C_NAME_SIZE];
273 unsigned short flags;
274 unsigned short addr;
275 void *platform_data;
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200276 struct dev_archdata *archdata;
Grant Likelyd12d42f2010-04-13 16:12:28 -0700277 struct device_node *of_node;
Mika Westerberg907ddf82012-11-23 12:23:40 +0100278 struct acpi_dev_node acpi_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 Delvare12b5053a2007-05-01 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 Delvare12b5053a2007-05-01 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 Delvare12b5053a2007-05-01 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
Ben Dooks25ee33f2014-01-26 16:05:36 +0000345/**
346 * struct i2c_algorithm - represent I2C transfer method
347 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
348 * defined by the msgs array, with num messages available to transfer via
349 * the adapter specified by adap.
350 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
351 * is not present, then the bus layer will try and convert the SMBus calls
352 * into I2C transfers instead.
353 * @functionality: Return the flags that this algorithm/adapter pair supports
354 * from the I2C_FUNC_* flags.
355 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 * The following structs are for those who like to implement new bus drivers:
357 * i2c_algorithm is the interface to a class of hardware solutions which can
358 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
359 * to name two of the most common.
Ben Dooks25ee33f2014-01-26 16:05:36 +0000360 *
361 * The return codes from the @master_xfer field should indicate the type of
362 * error code that occured during the transfer, as documented in the kernel
363 * Documentation file Documentation/i2c/fault-codes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 */
365struct i2c_algorithm {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 /* If an adapter algorithm can't do I2C-level access, set master_xfer
David Brownell438d6c22006-12-10 21:21:31 +0100367 to NULL. If an adapter algorithm can do SMBus access, set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 smbus_xfer. If set to NULL, the SMBus protocol is simulated
369 using common I2C messages */
Jean Delvare8ced8ee2006-07-01 17:12:53 +0200370 /* master_xfer should return the number of messages successfully
371 processed, or a negative value on error */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200372 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
373 int num);
David Brownell438d6c22006-12-10 21:21:31 +0100374 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200375 unsigned short flags, char read_write,
376 u8 command, int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 /* To determine what the adapter supports */
379 u32 (*functionality) (struct i2c_adapter *);
380};
381
Viresh Kumar5f9296b2012-02-28 18:26:31 +0530382/**
383 * struct i2c_bus_recovery_info - I2C bus recovery information
384 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
385 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
386 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
387 * recovery. Used internally for generic GPIO recovery.
388 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
389 * internally for generic GPIO recovery.
390 * @get_sda: This gets current value of SDA line. Optional for generic SCL
391 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
392 * recovery.
393 * @prepare_recovery: This will be called before starting recovery. Platform may
394 * configure padmux here for SDA/SCL line or something else they want.
395 * @unprepare_recovery: This will be called after completing recovery. Platform
396 * may configure padmux here for SDA/SCL line or something else they want.
397 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
398 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
399 */
400struct i2c_bus_recovery_info {
401 int (*recover_bus)(struct i2c_adapter *);
402
403 int (*get_scl)(struct i2c_adapter *);
404 void (*set_scl)(struct i2c_adapter *, int val);
405 int (*get_sda)(struct i2c_adapter *);
406
407 void (*prepare_recovery)(struct i2c_bus_recovery_info *bri);
408 void (*unprepare_recovery)(struct i2c_bus_recovery_info *bri);
409
410 /* gpio recovery */
411 int scl_gpio;
412 int sda_gpio;
413};
414
415int i2c_recover_bus(struct i2c_adapter *adap);
416
417/* Generic recovery routines */
418int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
419int i2c_generic_scl_recovery(struct i2c_adapter *adap);
420
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421/*
422 * i2c_adapter is the structure used to identify a physical i2c bus along
423 * with the access algorithms necessary to access it.
424 */
425struct i2c_adapter {
426 struct module *owner;
Wolfram Sang14f55f72008-10-22 20:21:30 +0200427 unsigned int class; /* classes to allow probing for */
David Brownellaf71ff62006-09-03 22:37:11 +0200428 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 void *algo_data;
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 /* data fields that are valid for all devices */
Mika Kuoppala194684e2009-12-06 17:06:22 +0100432 struct rt_mutex bus_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
Jean Delvarecd97f392009-02-24 19:19:49 +0100434 int timeout; /* in jiffies */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 int retries;
436 struct device dev; /* the adapter device */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 int nr;
David Brownell2096b952007-05-01 23:26:28 +0200439 char name[48];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 struct completion dev_released;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200441
Jean Delvaredafc50d2010-08-11 18:21:01 +0200442 struct mutex userspace_clients_lock;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200443 struct list_head userspace_clients;
Viresh Kumar5f9296b2012-02-28 18:26:31 +0530444
445 struct i2c_bus_recovery_info *bus_recovery_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446};
David Brownellef2c83212007-05-01 23:26:28 +0200447#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
Jean Delvare7d1d8992008-10-22 20:21:31 +0200449static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200451 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452}
453
Jean Delvare3ae70de2008-10-22 20:21:32 +0200454static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200456 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457}
458
Jean Delvare97cc4d42010-10-24 18:16:57 +0200459static inline struct i2c_adapter *
460i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
Michael Lawnick08263742010-08-11 18:21:02 +0200461{
Stephen Warren2fac2b82014-01-13 14:29:04 -0700462#if IS_ENABLED(CONFIG_I2C_MUX)
Jean Delvare97cc4d42010-10-24 18:16:57 +0200463 struct device *parent = adapter->dev.parent;
464
465 if (parent != NULL && parent->type == &i2c_adapter_type)
466 return to_i2c_adapter(parent);
467 else
Phil Carmody39231722013-06-26 10:56:35 +0300468#endif
Jean Delvare97cc4d42010-10-24 18:16:57 +0200469 return NULL;
Michael Lawnick08263742010-08-11 18:21:02 +0200470}
471
Jean Delvare7ae31482011-03-20 14:50:52 +0100472int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
473
Jean Delvarefe61e072010-08-11 18:20:58 +0200474/* Adapter locking functions, exported for shared pin cases */
475void i2c_lock_adapter(struct i2c_adapter *);
476void i2c_unlock_adapter(struct i2c_adapter *);
Jean Delvareafa08972009-11-07 13:10:46 +0100477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478/*flags for the client struct: */
David Brownell3bbb8352007-10-13 23:56:29 +0200479#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
480#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
481 /* Must equal I2C_M_TEN below */
482#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
Laurent Pinchartd47726c2012-07-24 14:13:59 +0200483#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
484 /* Must match I2C_M_STOP|IGNORE_NAK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
486/* i2c adapter classes (bitmask) */
487#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
Jean Delvarec1b6b4f2008-07-14 22:38:28 +0200488#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
Jean Delvare774466a2011-05-25 20:43:32 +0200489#define I2C_CLASS_SPD (1<<7) /* Memory modules */
Wolfram Sang0c176172014-02-10 11:03:56 +0100490#define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492/* Internal numbers to terminate lists */
493#define I2C_CLIENT_END 0xfffeU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
Hans Verkuilc7036672009-06-19 16:58:21 +0200495/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
496#define I2C_ADDRS(addr, addrs...) \
497 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
498
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
500/* ----- functions exported by i2c.o */
501
502/* administration...
503 */
Jean Delvare23af8402009-06-19 16:58:20 +0200504#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505extern int i2c_add_adapter(struct i2c_adapter *);
Lars-Peter Clausen71546302013-03-09 08:16:47 +0000506extern void i2c_del_adapter(struct i2c_adapter *);
David Brownell6e13e642007-05-01 23:26:31 +0200507extern int i2c_add_numbered_adapter(struct i2c_adapter *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800509extern int i2c_register_driver(struct module *, struct i2c_driver *);
Jean Delvareb3e82092007-05-01 23:26:32 +0200510extern void i2c_del_driver(struct i2c_driver *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511
Paul Gortmakereb5589a2011-05-27 09:02:11 -0400512/* use a define to avoid include chaining to get THIS_MODULE */
513#define i2c_add_driver(driver) \
514 i2c_register_driver(THIS_MODULE, driver)
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800515
Jean Delvaree48d3312008-01-27 18:14:48 +0100516extern struct i2c_client *i2c_use_client(struct i2c_client *client);
517extern void i2c_release_client(struct i2c_client *client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518
519/* call the i2c_client->command() of all attached clients with
520 * the given arguments */
521extern void i2c_clients_command(struct i2c_adapter *adap,
522 unsigned int cmd, void *arg);
523
Jean Delvared735b342011-03-20 14:50:52 +0100524extern struct i2c_adapter *i2c_get_adapter(int nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525extern void i2c_put_adapter(struct i2c_adapter *adap);
526
527
528/* Return the functionality mask */
529static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
530{
531 return adap->algo->functionality(adap);
532}
533
534/* Return 1 if adapter supports everything we need, 0 if not. */
535static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
536{
537 return (func & i2c_get_functionality(adap)) == func;
538}
539
Jean Delvare3ae70de2008-10-22 20:21:32 +0200540/* Return the adapter number for a specific adapter */
Jean Delvarecdcb1922005-07-28 23:09:40 +0200541static inline int i2c_adapter_id(struct i2c_adapter *adap)
542{
543 return adap->nr;
544}
Lars-Peter Clausen7c927842011-11-16 10:13:36 +0100545
546/**
547 * module_i2c_driver() - Helper macro for registering a I2C driver
548 * @__i2c_driver: i2c_driver struct
549 *
550 * Helper macro for I2C drivers which do not do anything special in module
551 * init/exit. This eliminates a lot of boilerplate. Each module may only
552 * use this macro once, and calling it replaces module_init() and module_exit()
553 */
554#define module_i2c_driver(__i2c_driver) \
555 module_driver(__i2c_driver, i2c_add_driver, \
556 i2c_del_driver)
557
Jean Delvare23af8402009-06-19 16:58:20 +0200558#endif /* I2C */
Mika Westerberg907ddf82012-11-23 12:23:40 +0100559
Wolfram Sang687b81d2013-07-11 12:56:15 +0100560#if IS_ENABLED(CONFIG_OF)
561/* must call put_device() when done with returned i2c_client device */
562extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
563
564/* must call put_device() when done with returned i2c_adapter device */
565extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
566
567#else
568
569static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
570{
571 return NULL;
572}
573
574static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
575{
576 return NULL;
577}
578#endif /* CONFIG_OF */
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580#endif /* _LINUX_I2C_H */