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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;
Wolfram Sang4b1acc42014-11-18 17:04:53 +010049enum i2c_slave_event;
50typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Paul Gortmakerde477252011-05-26 13:46:22 -040052struct module;
53
Jean Delvare23af8402009-06-19 16:58:20 +020054#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055/*
56 * The master routines are the ones normally used to transmit data to devices
David Brownell438d6c22006-12-10 21:21:31 +010057 * on a bus (or read from them). Apart from two basic transfer functions to
58 * transmit one message at a time, a more complex version can be used to
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * transmit an arbitrary number of messages without interruption.
Zhangfei Gao0c43ea52010-03-02 12:23:49 +010060 * @count must be be less than 64k since msg.len is u16.
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 */
Jean Delvare0cc43a12011-01-10 22:11:23 +010062extern int i2c_master_send(const struct i2c_client *client, const char *buf,
Jean Delvare3ae70de2008-10-22 20:21:32 +020063 int count);
Jean Delvare0cc43a12011-01-10 22:11:23 +010064extern int i2c_master_recv(const struct i2c_client *client, char *buf,
65 int count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67/* Transfer num messages.
68 */
Jean Delvare3ae70de2008-10-22 20:21:32 +020069extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
70 int num);
Jean Delvareb37d2a32012-06-29 07:47:19 -030071/* Unlocked flavor */
72extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
73 int num);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75/* This is the very generalized SMBus access routine. You probably do not
76 want to use this, though; one of the functions below may be much easier,
David Brownell438d6c22006-12-10 21:21:31 +010077 and probably just as fast.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 Note that we use i2c_adapter here, because you do not need a specific
79 smbus adapter to call this function. */
Jean Delvare3ae70de2008-10-22 20:21:32 +020080extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
81 unsigned short flags, char read_write, u8 command,
82 int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84/* Now follow the 'nice' access routines. These also document the calling
Jean Delvareae7193f2008-07-14 22:38:24 +020085 conventions of i2c_smbus_xfer. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Jean Delvare0cc43a12011-01-10 22:11:23 +010087extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
88extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
89extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
90 u8 command);
91extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020092 u8 command, u8 value);
Jean Delvare0cc43a12011-01-10 22:11:23 +010093extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
94 u8 command);
95extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +020096 u8 command, u16 value);
Jonathan Cameron06a67842011-10-30 13:47:25 +010097
98static inline s32
99i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
100{
101 s32 value = i2c_smbus_read_word_data(client, command);
102
103 return (value < 0) ? value : swab16(value);
104}
105
106static inline s32
107i2c_smbus_write_word_swapped(const struct i2c_client *client,
108 u8 command, u16 value)
109{
110 return i2c_smbus_write_word_data(client, command, swab16(value));
111}
112
Jean Delvareb86a1bc2007-05-01 23:26:34 +0200113/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +0100114extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
Jean Delvareb86a1bc2007-05-01 23:26:34 +0200115 u8 command, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +0100116extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200117 u8 command, u8 length, const u8 *values);
Jean Delvare31ec5bc2005-10-08 00:04:13 +0200118/* Returns the number of read bytes */
Jean Delvare0cc43a12011-01-10 22:11:23 +0100119extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
Jean Delvare4b2643d2007-07-12 14:12:29 +0200120 u8 command, u8 length, u8 *values);
Jean Delvare0cc43a12011-01-10 22:11:23 +0100121extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
Jean Delvare21bbd692006-01-09 15:19:18 +1100122 u8 command, u8 length,
Krzysztof Halasa46f5ed72006-06-12 21:42:20 +0200123 const u8 *values);
Jean Delvare23af8402009-06-19 16:58:20 +0200124#endif /* I2C */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Jean Delvare4735c982008-07-14 22:38:36 +0200126/**
127 * struct i2c_driver - represent an I2C device driver
128 * @class: What kind of i2c device we instantiate (for detect)
Jean Delvarefe6fc252011-03-20 14:50:53 +0100129 * @attach_adapter: Callback for bus addition (deprecated)
Jean Delvare729d6dd2009-06-19 16:58:18 +0200130 * @probe: Callback for device binding
131 * @remove: Callback for device unbinding
Jean Delvare96e21e42008-08-28 08:33:23 +0200132 * @shutdown: Callback for device shutdown
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 *);
David Brownellf37dd802007-02-13 22:09:00 +0100175
Jean Delvareb5527a72010-03-02 12:23:42 +0100176 /* Alert callback, for example for the SMBus alert protocol.
177 * The format and meaning of the data value depends on the protocol.
178 * For the SMBus alert protocol, there is a single bit of data passed
179 * as the alert response's low bit ("event flag").
180 */
181 void (*alert)(struct i2c_client *, unsigned int data);
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 /* a ioctl like command that can be used to perform specific functions
184 * with the device.
185 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200186 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188 struct device_driver driver;
Jean Delvared2653e92008-04-29 23:11:39 +0200189 const struct i2c_device_id *id_table;
Jean Delvare4735c982008-07-14 22:38:36 +0200190
191 /* Device detection callback for automatic device creation */
Jean Delvare310ec792009-12-14 21:17:23 +0100192 int (*detect)(struct i2c_client *, struct i2c_board_info *);
Jean Delvarec3813d62009-12-14 21:17:25 +0100193 const unsigned short *address_list;
Jean Delvare4735c982008-07-14 22:38:36 +0200194 struct list_head clients;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195};
196#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
197
David Brownell2096b952007-05-01 23:26:28 +0200198/**
199 * struct i2c_client - represent an I2C slave device
David Brownelld64f73b2007-07-12 14:12:28 +0200200 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
201 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
David Brownell2096b952007-05-01 23:26:28 +0200202 * @addr: Address used on the I2C bus connected to the parent adapter.
203 * @name: Indicates the type of the device, usually a chip name that's
204 * generic enough to hide second-sourcing and compatible revisions.
David Brownelld64f73b2007-07-12 14:12:28 +0200205 * @adapter: manages the bus segment hosting this I2C device
David Brownell2096b952007-05-01 23:26:28 +0200206 * @dev: Driver model device node for the slave.
David Brownelld64f73b2007-07-12 14:12:28 +0200207 * @irq: indicates the IRQ generated by this device (if any)
Jean Delvare99cd8e22009-06-19 16:58:20 +0200208 * @detected: member of an i2c_driver.clients list or i2c-core's
209 * userspace_devices list
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100210 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
211 * calls it to pass on slave events to the slave driver.
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;
Jean Delvared5fd1202015-01-26 20:59:31 +0100227#if IS_ENABLED(CONFIG_I2C_SLAVE)
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100228 i2c_slave_cb_t slave_cb; /* callback for slave mode */
Jean Delvared5fd1202015-01-26 20:59:31 +0100229#endif
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);
Stephen Warren643dd092012-04-17 12:43:33 -0600234extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
David Brownell9b766b82008-01-27 18:14:51 +0100235
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500236static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
237{
Mark M. Hoffmand75d53c2007-07-12 14:12:28 +0200238 struct device * const dev = container_of(kobj, struct device, kobj);
239 return to_i2c_client(dev);
bgardner@wabtec.coma61fc682005-07-27 12:43:03 -0500240}
241
Jean Delvare7d1d8992008-10-22 20:21:31 +0200242static inline void *i2c_get_clientdata(const struct i2c_client *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200244 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245}
246
Jean Delvare3ae70de2008-10-22 20:21:32 +0200247static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200249 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
251
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100252/* I2C slave support */
253
Jean Delvared5fd1202015-01-26 20:59:31 +0100254#if IS_ENABLED(CONFIG_I2C_SLAVE)
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100255enum i2c_slave_event {
Wolfram Sang5b77d162015-03-23 09:26:36 +0100256 I2C_SLAVE_READ_REQUESTED,
257 I2C_SLAVE_WRITE_REQUESTED,
258 I2C_SLAVE_READ_PROCESSED,
259 I2C_SLAVE_WRITE_RECEIVED,
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100260 I2C_SLAVE_STOP,
261};
262
263extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
264extern int i2c_slave_unregister(struct i2c_client *client);
265
266static inline int i2c_slave_event(struct i2c_client *client,
267 enum i2c_slave_event event, u8 *val)
268{
269 return client->slave_cb(client, event, val);
270}
Jean Delvared5fd1202015-01-26 20:59:31 +0100271#endif
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100272
David Brownell9c1600e2007-05-01 23:26:31 +0200273/**
274 * struct i2c_board_info - template for device creation
Jean Delvareeb8a7902008-05-18 20:49:41 +0200275 * @type: chip type, to initialize i2c_client.name
David Brownell9c1600e2007-05-01 23:26:31 +0200276 * @flags: to initialize i2c_client.flags
277 * @addr: stored in i2c_client.addr
278 * @platform_data: stored in i2c_client.dev.platform_data
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200279 * @archdata: copied into i2c_client.dev.archdata
Randy Dunlap72d2e9f2010-08-09 16:37:16 -0700280 * @of_node: pointer to OpenFirmware device node
Rafael J. Wysockice793482015-03-16 23:49:03 +0100281 * @fwnode: device node supplied by the platform firmware
David Brownell9c1600e2007-05-01 23:26:31 +0200282 * @irq: stored in i2c_client.irq
David Brownelld64f73b2007-07-12 14:12:28 +0200283 *
David Brownell9c1600e2007-05-01 23:26:31 +0200284 * I2C doesn't actually support hardware probing, although controllers and
285 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
286 * a device at a given address. Drivers commonly need more information than
287 * that, such as chip type, configuration, associated IRQ, and so on.
288 *
289 * i2c_board_info is used to build tables of information listing I2C devices
Jean Delvare729d6dd2009-06-19 16:58:18 +0200290 * that are present. This information is used to grow the driver model tree.
291 * For mainboards this is done statically using i2c_register_board_info();
292 * bus numbers identify adapters that aren't yet available. For add-on boards,
293 * i2c_new_device() does this dynamically with the adapter already known.
David Brownell9c1600e2007-05-01 23:26:31 +0200294 */
295struct i2c_board_info {
David Brownell9c1600e2007-05-01 23:26:31 +0200296 char type[I2C_NAME_SIZE];
297 unsigned short flags;
298 unsigned short addr;
299 void *platform_data;
Anton Vorontsov11f1f2a2008-10-22 20:21:33 +0200300 struct dev_archdata *archdata;
Grant Likelyd12d42f2010-04-13 16:12:28 -0700301 struct device_node *of_node;
Rafael J. Wysockice793482015-03-16 23:49:03 +0100302 struct fwnode_handle *fwnode;
David Brownell9c1600e2007-05-01 23:26:31 +0200303 int irq;
304};
305
306/**
Jean Delvare3760f732008-04-29 23:11:40 +0200307 * I2C_BOARD_INFO - macro used to list an i2c device and its address
308 * @dev_type: identifies the device type
David Brownell9c1600e2007-05-01 23:26:31 +0200309 * @dev_addr: the device's address on the bus.
310 *
311 * This macro initializes essential fields of a struct i2c_board_info,
312 * declaring what has been provided on a particular board. Optional
Jean Delvare3760f732008-04-29 23:11:40 +0200313 * fields (such as associated irq, or device-specific platform_data)
314 * are provided using conventional syntax.
David Brownell9c1600e2007-05-01 23:26:31 +0200315 */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200316#define I2C_BOARD_INFO(dev_type, dev_addr) \
Ben Hutchingsc758e8c2009-04-13 17:02:14 +0200317 .type = dev_type, .addr = (dev_addr)
David Brownell9c1600e2007-05-01 23:26:31 +0200318
319
Jean Delvare23af8402009-06-19 16:58:20 +0200320#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
David Brownell9c1600e2007-05-01 23:26:31 +0200321/* Add-on boards should register/unregister their devices; e.g. a board
322 * with integrated I2C, a config eeprom, sensors, and a codec that's
323 * used in conjunction with the primary hardware.
324 */
325extern struct i2c_client *
326i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
327
Jean Delvare12b5053a2007-05-01 23:26:31 +0200328/* If you don't know the exact address of an I2C device, use this variant
329 * instead, which can probe for device presence in a list of possible
Jean Delvare9a942412010-08-11 18:20:56 +0200330 * addresses. The "probe" callback function is optional. If it is provided,
331 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
332 * a default probing method is used.
Jean Delvare12b5053a2007-05-01 23:26:31 +0200333 */
334extern struct i2c_client *
335i2c_new_probed_device(struct i2c_adapter *adap,
336 struct i2c_board_info *info,
Jean Delvare9a942412010-08-11 18:20:56 +0200337 unsigned short const *addr_list,
338 int (*probe)(struct i2c_adapter *, unsigned short addr));
Jean Delvare12b5053a2007-05-01 23:26:31 +0200339
Jean Delvared44f19d2010-08-11 18:20:57 +0200340/* Common custom probe functions */
341extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
342
David Brownelle9f13732008-01-27 18:14:52 +0100343/* For devices that use several addresses, use i2c_new_dummy() to make
344 * client handles for the extra addresses.
345 */
346extern struct i2c_client *
Jean Delvare60b129d2008-05-11 20:37:06 +0200347i2c_new_dummy(struct i2c_adapter *adap, u16 address);
David Brownelle9f13732008-01-27 18:14:52 +0100348
David Brownell9c1600e2007-05-01 23:26:31 +0200349extern void i2c_unregister_device(struct i2c_client *);
Jean Delvare23af8402009-06-19 16:58:20 +0200350#endif /* I2C */
David Brownell9c1600e2007-05-01 23:26:31 +0200351
352/* Mainboard arch_initcall() code should register all its I2C devices.
353 * This is done at arch_initcall time, before declaring any i2c adapters.
354 * Modules for add-on boards must use other calls.
355 */
David Brownell26386762008-02-24 20:03:42 +0100356#ifdef CONFIG_I2C_BOARDINFO
David Brownell9c1600e2007-05-01 23:26:31 +0200357extern int
Jean Delvare3ae70de2008-10-22 20:21:32 +0200358i2c_register_board_info(int busnum, struct i2c_board_info const *info,
359 unsigned n);
David Brownell26386762008-02-24 20:03:42 +0100360#else
361static inline int
Jean Delvare3ae70de2008-10-22 20:21:32 +0200362i2c_register_board_info(int busnum, struct i2c_board_info const *info,
363 unsigned n)
David Brownell26386762008-02-24 20:03:42 +0100364{
365 return 0;
366}
Jean Delvare23af8402009-06-19 16:58:20 +0200367#endif /* I2C_BOARDINFO */
David Brownell9c1600e2007-05-01 23:26:31 +0200368
Ben Dooks25ee33f2014-01-26 16:05:36 +0000369/**
370 * struct i2c_algorithm - represent I2C transfer method
371 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
372 * defined by the msgs array, with num messages available to transfer via
373 * the adapter specified by adap.
374 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
375 * is not present, then the bus layer will try and convert the SMBus calls
376 * into I2C transfers instead.
377 * @functionality: Return the flags that this algorithm/adapter pair supports
378 * from the I2C_FUNC_* flags.
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100379 * @reg_slave: Register given client to I2C slave mode of this adapter
380 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
Ben Dooks25ee33f2014-01-26 16:05:36 +0000381 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 * The following structs are for those who like to implement new bus drivers:
383 * i2c_algorithm is the interface to a class of hardware solutions which can
384 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
385 * to name two of the most common.
Ben Dooks25ee33f2014-01-26 16:05:36 +0000386 *
387 * The return codes from the @master_xfer field should indicate the type of
Masanari Iidaf353d712014-10-22 00:00:14 +0900388 * error code that occurred during the transfer, as documented in the kernel
Ben Dooks25ee33f2014-01-26 16:05:36 +0000389 * Documentation file Documentation/i2c/fault-codes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 */
391struct i2c_algorithm {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 /* If an adapter algorithm can't do I2C-level access, set master_xfer
David Brownell438d6c22006-12-10 21:21:31 +0100393 to NULL. If an adapter algorithm can do SMBus access, set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 smbus_xfer. If set to NULL, the SMBus protocol is simulated
395 using common I2C messages */
Jean Delvare8ced8ee2006-07-01 17:12:53 +0200396 /* master_xfer should return the number of messages successfully
397 processed, or a negative value on error */
Jean Delvare3ae70de2008-10-22 20:21:32 +0200398 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
399 int num);
David Brownell438d6c22006-12-10 21:21:31 +0100400 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
Jean Delvare3ae70de2008-10-22 20:21:32 +0200401 unsigned short flags, char read_write,
402 u8 command, int size, union i2c_smbus_data *data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 /* To determine what the adapter supports */
405 u32 (*functionality) (struct i2c_adapter *);
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100406
Jean Delvared5fd1202015-01-26 20:59:31 +0100407#if IS_ENABLED(CONFIG_I2C_SLAVE)
Wolfram Sang4b1acc42014-11-18 17:04:53 +0100408 int (*reg_slave)(struct i2c_client *client);
409 int (*unreg_slave)(struct i2c_client *client);
Jean Delvared5fd1202015-01-26 20:59:31 +0100410#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411};
412
Viresh Kumar5f9296b2012-02-28 18:26:31 +0530413/**
414 * struct i2c_bus_recovery_info - I2C bus recovery information
415 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
416 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
417 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
418 * recovery. Used internally for generic GPIO recovery.
419 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
420 * internally for generic GPIO recovery.
421 * @get_sda: This gets current value of SDA line. Optional for generic SCL
422 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
423 * recovery.
424 * @prepare_recovery: This will be called before starting recovery. Platform may
425 * configure padmux here for SDA/SCL line or something else they want.
426 * @unprepare_recovery: This will be called after completing recovery. Platform
427 * may configure padmux here for SDA/SCL line or something else they want.
428 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
429 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
430 */
431struct i2c_bus_recovery_info {
432 int (*recover_bus)(struct i2c_adapter *);
433
434 int (*get_scl)(struct i2c_adapter *);
435 void (*set_scl)(struct i2c_adapter *, int val);
436 int (*get_sda)(struct i2c_adapter *);
437
Grygorii Strashko2b2190a2015-04-06 15:38:39 +0300438 void (*prepare_recovery)(struct i2c_adapter *);
439 void (*unprepare_recovery)(struct i2c_adapter *);
Viresh Kumar5f9296b2012-02-28 18:26:31 +0530440
441 /* gpio recovery */
442 int scl_gpio;
443 int sda_gpio;
444};
445
446int i2c_recover_bus(struct i2c_adapter *adap);
447
448/* Generic recovery routines */
449int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
450int i2c_generic_scl_recovery(struct i2c_adapter *adap);
451
Wolfram Sang2187f032015-01-05 15:35:39 +0100452/**
453 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
454 * @flags: see I2C_AQ_* for possible flags and read below
455 * @max_num_msgs: maximum number of messages per transfer
456 * @max_write_len: maximum length of a write message
457 * @max_read_len: maximum length of a read message
458 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
459 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
460 *
461 * Note about combined messages: Some I2C controllers can only send one message
462 * per transfer, plus something called combined message or write-then-read.
463 * This is (usually) a small write message followed by a read message and
464 * barely enough to access register based devices like EEPROMs. There is a flag
465 * to support this mode. It implies max_num_msg = 2 and does the length checks
466 * with max_comb_*_len because combined message mode usually has its own
467 * limitations. Because of HW implementations, some controllers can actually do
468 * write-then-anything or other variants. To support that, write-then-read has
469 * been broken out into smaller bits like write-first and read-second which can
470 * be combined as needed.
471 */
472
473struct i2c_adapter_quirks {
474 u64 flags;
475 int max_num_msgs;
476 u16 max_write_len;
477 u16 max_read_len;
478 u16 max_comb_1st_msg_len;
479 u16 max_comb_2nd_msg_len;
480};
481
482/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
483#define I2C_AQ_COMB BIT(0)
484/* first combined message must be write */
485#define I2C_AQ_COMB_WRITE_FIRST BIT(1)
486/* second combined message must be read */
487#define I2C_AQ_COMB_READ_SECOND BIT(2)
488/* both combined messages must have the same target address */
489#define I2C_AQ_COMB_SAME_ADDR BIT(3)
490/* convenience macro for typical write-then read case */
491#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \
492 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494/*
495 * i2c_adapter is the structure used to identify a physical i2c bus along
496 * with the access algorithms necessary to access it.
497 */
498struct i2c_adapter {
499 struct module *owner;
Wolfram Sang14f55f72008-10-22 20:21:30 +0200500 unsigned int class; /* classes to allow probing for */
David Brownellaf71ff62006-09-03 22:37:11 +0200501 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 void *algo_data;
503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 /* data fields that are valid for all devices */
Mika Kuoppala194684e2009-12-06 17:06:22 +0100505 struct rt_mutex bus_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
Jean Delvarecd97f392009-02-24 19:19:49 +0100507 int timeout; /* in jiffies */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 int retries;
509 struct device dev; /* the adapter device */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 int nr;
David Brownell2096b952007-05-01 23:26:28 +0200512 char name[48];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 struct completion dev_released;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200514
Jean Delvaredafc50d2010-08-11 18:21:01 +0200515 struct mutex userspace_clients_lock;
Jean Delvare6629dcf2010-05-04 11:09:28 +0200516 struct list_head userspace_clients;
Viresh Kumar5f9296b2012-02-28 18:26:31 +0530517
518 struct i2c_bus_recovery_info *bus_recovery_info;
Wolfram Sang2187f032015-01-05 15:35:39 +0100519 const struct i2c_adapter_quirks *quirks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520};
David Brownellef2c83212007-05-01 23:26:28 +0200521#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
Jean Delvare7d1d8992008-10-22 20:21:31 +0200523static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200525 return dev_get_drvdata(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526}
527
Jean Delvare3ae70de2008-10-22 20:21:32 +0200528static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529{
Jean Delvare3ae70de2008-10-22 20:21:32 +0200530 dev_set_drvdata(&dev->dev, data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531}
532
Jean Delvare97cc4d42010-10-24 18:16:57 +0200533static inline struct i2c_adapter *
534i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
Michael Lawnick08263742010-08-11 18:21:02 +0200535{
Stephen Warren2fac2b82014-01-13 14:29:04 -0700536#if IS_ENABLED(CONFIG_I2C_MUX)
Jean Delvare97cc4d42010-10-24 18:16:57 +0200537 struct device *parent = adapter->dev.parent;
538
539 if (parent != NULL && parent->type == &i2c_adapter_type)
540 return to_i2c_adapter(parent);
541 else
Phil Carmody39231722013-06-26 10:56:35 +0300542#endif
Jean Delvare97cc4d42010-10-24 18:16:57 +0200543 return NULL;
Michael Lawnick08263742010-08-11 18:21:02 +0200544}
545
Jean Delvare7ae31482011-03-20 14:50:52 +0100546int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
547
Jean Delvarefe61e072010-08-11 18:20:58 +0200548/* Adapter locking functions, exported for shared pin cases */
549void i2c_lock_adapter(struct i2c_adapter *);
550void i2c_unlock_adapter(struct i2c_adapter *);
Jean Delvareafa08972009-11-07 13:10:46 +0100551
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552/*flags for the client struct: */
David Brownell3bbb8352007-10-13 23:56:29 +0200553#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
554#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
555 /* Must equal I2C_M_TEN below */
556#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
Laurent Pinchartd47726c2012-07-24 14:13:59 +0200557#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
558 /* Must match I2C_M_STOP|IGNORE_NAK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560/* i2c adapter classes (bitmask) */
561#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
Jean Delvarec1b6b4f2008-07-14 22:38:28 +0200562#define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
Jean Delvare774466a2011-05-25 20:43:32 +0200563#define I2C_CLASS_SPD (1<<7) /* Memory modules */
Wolfram Sang0c176172014-02-10 11:03:56 +0100564#define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566/* Internal numbers to terminate lists */
567#define I2C_CLIENT_END 0xfffeU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
Hans Verkuilc7036672009-06-19 16:58:21 +0200569/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
570#define I2C_ADDRS(addr, addrs...) \
571 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
572
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
574/* ----- functions exported by i2c.o */
575
576/* administration...
577 */
Jean Delvare23af8402009-06-19 16:58:20 +0200578#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579extern int i2c_add_adapter(struct i2c_adapter *);
Lars-Peter Clausen71546302013-03-09 08:16:47 +0000580extern void i2c_del_adapter(struct i2c_adapter *);
David Brownell6e13e642007-05-01 23:26:31 +0200581extern int i2c_add_numbered_adapter(struct i2c_adapter *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800583extern int i2c_register_driver(struct module *, struct i2c_driver *);
Jean Delvareb3e82092007-05-01 23:26:32 +0200584extern void i2c_del_driver(struct i2c_driver *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
Paul Gortmakereb5589a2011-05-27 09:02:11 -0400586/* use a define to avoid include chaining to get THIS_MODULE */
587#define i2c_add_driver(driver) \
588 i2c_register_driver(THIS_MODULE, driver)
Greg Kroah-Hartmande59cf92005-12-06 15:33:15 -0800589
Jean Delvaree48d3312008-01-27 18:14:48 +0100590extern struct i2c_client *i2c_use_client(struct i2c_client *client);
591extern void i2c_release_client(struct i2c_client *client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
593/* call the i2c_client->command() of all attached clients with
594 * the given arguments */
595extern void i2c_clients_command(struct i2c_adapter *adap,
596 unsigned int cmd, void *arg);
597
Jean Delvared735b342011-03-20 14:50:52 +0100598extern struct i2c_adapter *i2c_get_adapter(int nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599extern void i2c_put_adapter(struct i2c_adapter *adap);
600
601
602/* Return the functionality mask */
603static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
604{
605 return adap->algo->functionality(adap);
606}
607
608/* Return 1 if adapter supports everything we need, 0 if not. */
609static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
610{
611 return (func & i2c_get_functionality(adap)) == func;
612}
613
Jean Delvare3ae70de2008-10-22 20:21:32 +0200614/* Return the adapter number for a specific adapter */
Jean Delvarecdcb1922005-07-28 23:09:40 +0200615static inline int i2c_adapter_id(struct i2c_adapter *adap)
616{
617 return adap->nr;
618}
Lars-Peter Clausen7c927842011-11-16 10:13:36 +0100619
620/**
621 * module_i2c_driver() - Helper macro for registering a I2C driver
622 * @__i2c_driver: i2c_driver struct
623 *
624 * Helper macro for I2C drivers which do not do anything special in module
625 * init/exit. This eliminates a lot of boilerplate. Each module may only
626 * use this macro once, and calling it replaces module_init() and module_exit()
627 */
628#define module_i2c_driver(__i2c_driver) \
629 module_driver(__i2c_driver, i2c_add_driver, \
630 i2c_del_driver)
631
Jean Delvare23af8402009-06-19 16:58:20 +0200632#endif /* I2C */
Mika Westerberg907ddf82012-11-23 12:23:40 +0100633
Wolfram Sang687b81d2013-07-11 12:56:15 +0100634#if IS_ENABLED(CONFIG_OF)
635/* must call put_device() when done with returned i2c_client device */
636extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
637
638/* must call put_device() when done with returned i2c_adapter device */
639extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
640
641#else
642
643static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
644{
645 return NULL;
646}
647
648static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
649{
650 return NULL;
651}
652#endif /* CONFIG_OF */
653
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654#endif /* _LINUX_I2C_H */