i2c.h 23 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1
/* ------------------------------------------------------------------------- */
David Brownell's avatar
David Brownell committed
2
/*									     */
Linus Torvalds's avatar
Linus Torvalds committed
3
/* i2c.h - definitions for the i2c-bus interface			     */
David Brownell's avatar
David Brownell committed
4
/*									     */
Linus Torvalds's avatar
Linus Torvalds committed
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/* ------------------------------------------------------------------------- */
/*   Copyright (C) 1995-2000 Simon G. Vogl

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     */
/* ------------------------------------------------------------------------- */

23
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
Linus Torvalds's avatar
Linus Torvalds committed
24 25 26 27 28 29
   Frodo Looijaard <frodol@dds.nl> */

#ifndef _LINUX_I2C_H
#define _LINUX_I2C_H

#include <linux/types.h>
David Brownell's avatar
David Brownell committed
30
#ifdef __KERNEL__
31
#include <linux/module.h>
Linus Torvalds's avatar
Linus Torvalds committed
32
#include <linux/i2c-id.h>
33
#include <linux/mod_devicetable.h>
Linus Torvalds's avatar
Linus Torvalds committed
34
#include <linux/device.h>	/* for struct device */
Tim Schmielau's avatar
Tim Schmielau committed
35
#include <linux/sched.h>	/* for completion */
36
#include <linux/mutex.h>
Linus Torvalds's avatar
Linus Torvalds committed
37

38 39
extern struct bus_type i2c_bus_type;

Linus Torvalds's avatar
Linus Torvalds committed
40 41 42 43 44 45 46 47
/* --- General options ------------------------------------------------	*/

struct i2c_msg;
struct i2c_algorithm;
struct i2c_adapter;
struct i2c_client;
struct i2c_driver;
union i2c_smbus_data;
48
struct i2c_board_info;
Linus Torvalds's avatar
Linus Torvalds committed
49

50
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds's avatar
Linus Torvalds committed
51 52
/*
 * The master routines are the ones normally used to transmit data to devices
David Brownell's avatar
David Brownell committed
53 54
 * on a bus (or read from them). Apart from two basic transfer functions to
 * transmit one message at a time, a more complex version can be used to
Linus Torvalds's avatar
Linus Torvalds committed
55 56
 * transmit an arbitrary number of messages without interruption.
 */
Jean Delvare's avatar
Jean Delvare committed
57 58 59
extern int i2c_master_send(struct i2c_client *client, const char *buf,
			   int count);
extern int i2c_master_recv(struct i2c_client *client, char *buf, int count);
Linus Torvalds's avatar
Linus Torvalds committed
60 61 62

/* Transfer num messages.
 */
Jean Delvare's avatar
Jean Delvare committed
63 64
extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
			int num);
Linus Torvalds's avatar
Linus Torvalds committed
65 66 67

/* This is the very generalized SMBus access routine. You probably do not
   want to use this, though; one of the functions below may be much easier,
David Brownell's avatar
David Brownell committed
68
   and probably just as fast.
Linus Torvalds's avatar
Linus Torvalds committed
69 70
   Note that we use i2c_adapter here, because you do not need a specific
   smbus adapter to call this function. */
Jean Delvare's avatar
Jean Delvare committed
71 72 73
extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
			  unsigned short flags, char read_write, u8 command,
			  int size, union i2c_smbus_data *data);
Linus Torvalds's avatar
Linus Torvalds committed
74 75

/* Now follow the 'nice' access routines. These also document the calling
76
   conventions of i2c_smbus_xfer. */
Linus Torvalds's avatar
Linus Torvalds committed
77

Jean Delvare's avatar
Jean Delvare committed
78 79 80 81 82 83 84 85
extern s32 i2c_smbus_read_byte(struct i2c_client *client);
extern s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value);
extern s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command);
extern s32 i2c_smbus_write_byte_data(struct i2c_client *client,
				     u8 command, u8 value);
extern s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command);
extern s32 i2c_smbus_write_word_data(struct i2c_client *client,
				     u8 command, u16 value);
86 87 88
/* Returns the number of read bytes */
extern s32 i2c_smbus_read_block_data(struct i2c_client *client,
				     u8 command, u8 *values);
Jean Delvare's avatar
Jean Delvare committed
89 90
extern s32 i2c_smbus_write_block_data(struct i2c_client *client,
				      u8 command, u8 length, const u8 *values);
91
/* Returns the number of read bytes */
Jean Delvare's avatar
Jean Delvare committed
92
extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client,
93
					 u8 command, u8 length, u8 *values);
Jean Delvare's avatar
Jean Delvare committed
94
extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
95
					  u8 command, u8 length,
96
					  const u8 *values);
97
#endif /* I2C */
Linus Torvalds's avatar
Linus Torvalds committed
98

99 100 101
/**
 * struct i2c_driver - represent an I2C device driver
 * @class: What kind of i2c device we instantiate (for detect)
102 103
 * @attach_adapter: Callback for bus addition (for legacy drivers)
 * @detach_adapter: Callback for bus removal (for legacy drivers)
104 105
 * @probe: Callback for device binding
 * @remove: Callback for device unbinding
106 107 108 109 110 111
 * @shutdown: Callback for device shutdown
 * @suspend: Callback for device suspend
 * @resume: Callback for device resume
 * @command: Callback for bus-wide signaling (optional)
 * @driver: Device driver model driver
 * @id_table: List of I2C devices supported by this driver
112
 * @detect: Callback for device detection
113
 * @address_list: The I2C addresses to probe (for detect)
114
 * @clients: List of detected clients we created (for i2c-core use only)
115 116 117
 *
 * The driver.owner field should be set to the module owner of this driver.
 * The driver.name field should be set to the name of this driver.
118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
 *
 * For automatic device detection, both @detect and @address_data must
 * be defined. @class should also be set, otherwise only devices forced
 * with module parameters will be created. The detect function must
 * fill at least the name field of the i2c_board_info structure it is
 * handed upon successful detection, and possibly also the flags field.
 *
 * If @detect is missing, the driver will still work fine for enumerated
 * devices. Detected devices simply won't be supported. This is expected
 * for the many I2C/SMBus devices which can't be detected reliably, and
 * the ones which can always be enumerated in practice.
 *
 * The i2c_client structure which is handed to the @detect callback is
 * not a real i2c_client. It is initialized just enough so that you can
 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
 * else with it. In particular, calling dev_dbg and friends on it is
 * not allowed.
Linus Torvalds's avatar
Linus Torvalds committed
135 136 137 138
 */
struct i2c_driver {
	unsigned int class;

139 140 141
	/* Notifies the driver that a new bus has appeared or is about to be
	 * removed. You should avoid using this if you can, it will probably
	 * be removed in a near future.
Linus Torvalds's avatar
Linus Torvalds committed
142 143 144 145
	 */
	int (*attach_adapter)(struct i2c_adapter *);
	int (*detach_adapter)(struct i2c_adapter *);

146
	/* Standard driver model interfaces */
147
	int (*probe)(struct i2c_client *, const struct i2c_device_id *);
David Brownell's avatar
David Brownell committed
148
	int (*remove)(struct i2c_client *);
David Brownell's avatar
David Brownell committed
149

150 151 152 153 154
	/* driver model interfaces that don't relate to enumeration  */
	void (*shutdown)(struct i2c_client *);
	int (*suspend)(struct i2c_client *, pm_message_t mesg);
	int (*resume)(struct i2c_client *);

Linus Torvalds's avatar
Linus Torvalds committed
155 156 157
	/* a ioctl like command that can be used to perform specific functions
	 * with the device.
	 */
Jean Delvare's avatar
Jean Delvare committed
158
	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
Linus Torvalds's avatar
Linus Torvalds committed
159 160

	struct device_driver driver;
161
	const struct i2c_device_id *id_table;
162 163

	/* Device detection callback for automatic device creation */
164
	int (*detect)(struct i2c_client *, struct i2c_board_info *);
165
	const unsigned short *address_list;
166
	struct list_head clients;
Linus Torvalds's avatar
Linus Torvalds committed
167 168 169
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)

David Brownell's avatar
David Brownell committed
170 171
/**
 * struct i2c_client - represent an I2C slave device
David Brownell's avatar
David Brownell committed
172 173
 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
 *	I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
David Brownell's avatar
David Brownell committed
174 175 176
 * @addr: Address used on the I2C bus connected to the parent adapter.
 * @name: Indicates the type of the device, usually a chip name that's
 *	generic enough to hide second-sourcing and compatible revisions.
David Brownell's avatar
David Brownell committed
177
 * @adapter: manages the bus segment hosting this I2C device
Randy Dunlap's avatar
Randy Dunlap committed
178
 * @driver: device's driver, hence pointer to access routines
David Brownell's avatar
David Brownell committed
179
 * @dev: Driver model device node for the slave.
David Brownell's avatar
David Brownell committed
180
 * @irq: indicates the IRQ generated by this device (if any)
181 182
 * @detected: member of an i2c_driver.clients list or i2c-core's
 *	userspace_devices list
David Brownell's avatar
David Brownell committed
183 184
 *
 * An i2c_client identifies a single device (i.e. chip) connected to an
David Brownell's avatar
David Brownell committed
185 186
 * i2c bus. The behaviour exposed to Linux is defined by the driver
 * managing the device.
Linus Torvalds's avatar
Linus Torvalds committed
187 188
 */
struct i2c_client {
David Brownell's avatar
David Brownell committed
189
	unsigned short flags;		/* div., see below		*/
David Brownell's avatar
David Brownell committed
190
	unsigned short addr;		/* chip address - NOTE: 7bit	*/
Linus Torvalds's avatar
Linus Torvalds committed
191
					/* addresses are stored in the	*/
192
					/* _LOWER_ 7 bits		*/
David Brownell's avatar
David Brownell committed
193
	char name[I2C_NAME_SIZE];
Linus Torvalds's avatar
Linus Torvalds committed
194 195 196
	struct i2c_adapter *adapter;	/* the adapter we sit on	*/
	struct i2c_driver *driver;	/* and our access routines	*/
	struct device dev;		/* the device structure		*/
197
	int irq;			/* irq issued by device		*/
198
	struct list_head detected;
Linus Torvalds's avatar
Linus Torvalds committed
199 200 201
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)

202 203
extern struct i2c_client *i2c_verify_client(struct device *dev);

204 205
static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
{
206 207
	struct device * const dev = container_of(kobj, struct device, kobj);
	return to_i2c_client(dev);
208 209
}

210
static inline void *i2c_get_clientdata(const struct i2c_client *dev)
Linus Torvalds's avatar
Linus Torvalds committed
211
{
Jean Delvare's avatar
Jean Delvare committed
212
	return dev_get_drvdata(&dev->dev);
Linus Torvalds's avatar
Linus Torvalds committed
213 214
}

Jean Delvare's avatar
Jean Delvare committed
215
static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
Linus Torvalds's avatar
Linus Torvalds committed
216
{
Jean Delvare's avatar
Jean Delvare committed
217
	dev_set_drvdata(&dev->dev, data);
Linus Torvalds's avatar
Linus Torvalds committed
218 219
}

220 221
/**
 * struct i2c_board_info - template for device creation
222
 * @type: chip type, to initialize i2c_client.name
223 224 225
 * @flags: to initialize i2c_client.flags
 * @addr: stored in i2c_client.addr
 * @platform_data: stored in i2c_client.dev.platform_data
226
 * @archdata: copied into i2c_client.dev.archdata
227
 * @irq: stored in i2c_client.irq
David Brownell's avatar
David Brownell committed
228
 *
229 230 231 232 233 234
 * I2C doesn't actually support hardware probing, although controllers and
 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
 * a device at a given address.  Drivers commonly need more information than
 * that, such as chip type, configuration, associated IRQ, and so on.
 *
 * i2c_board_info is used to build tables of information listing I2C devices
235 236 237 238
 * that are present.  This information is used to grow the driver model tree.
 * For mainboards this is done statically using i2c_register_board_info();
 * bus numbers identify adapters that aren't yet available.  For add-on boards,
 * i2c_new_device() does this dynamically with the adapter already known.
239 240 241 242 243 244
 */
struct i2c_board_info {
	char		type[I2C_NAME_SIZE];
	unsigned short	flags;
	unsigned short	addr;
	void		*platform_data;
245
	struct dev_archdata	*archdata;
246 247 248 249
	int		irq;
};

/**
250 251
 * I2C_BOARD_INFO - macro used to list an i2c device and its address
 * @dev_type: identifies the device type
252 253 254 255
 * @dev_addr: the device's address on the bus.
 *
 * This macro initializes essential fields of a struct i2c_board_info,
 * declaring what has been provided on a particular board.  Optional
256 257
 * fields (such as associated irq, or device-specific platform_data)
 * are provided using conventional syntax.
258
 */
Jean Delvare's avatar
Jean Delvare committed
259
#define I2C_BOARD_INFO(dev_type, dev_addr) \
260
	.type = dev_type, .addr = (dev_addr)
261 262


263
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
264 265 266 267 268 269 270
/* Add-on boards should register/unregister their devices; e.g. a board
 * with integrated I2C, a config eeprom, sensors, and a codec that's
 * used in conjunction with the primary hardware.
 */
extern struct i2c_client *
i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);

271 272 273 274 275 276 277 278 279
/* If you don't know the exact address of an I2C device, use this variant
 * instead, which can probe for device presence in a list of possible
 * addresses.
 */
extern struct i2c_client *
i2c_new_probed_device(struct i2c_adapter *adap,
		      struct i2c_board_info *info,
		      unsigned short const *addr_list);

280 281 282 283
/* For devices that use several addresses, use i2c_new_dummy() to make
 * client handles for the extra addresses.
 */
extern struct i2c_client *
284
i2c_new_dummy(struct i2c_adapter *adap, u16 address);
285

286
extern void i2c_unregister_device(struct i2c_client *);
287
#endif /* I2C */
288 289 290 291 292

/* Mainboard arch_initcall() code should register all its I2C devices.
 * This is done at arch_initcall time, before declaring any i2c adapters.
 * Modules for add-on boards must use other calls.
 */
293
#ifdef CONFIG_I2C_BOARDINFO
294
extern int
Jean Delvare's avatar
Jean Delvare committed
295 296
i2c_register_board_info(int busnum, struct i2c_board_info const *info,
			unsigned n);
297 298
#else
static inline int
Jean Delvare's avatar
Jean Delvare committed
299 300
i2c_register_board_info(int busnum, struct i2c_board_info const *info,
			unsigned n)
301 302 303
{
	return 0;
}
304
#endif /* I2C_BOARDINFO */
305

Linus Torvalds's avatar
Linus Torvalds committed
306 307 308 309 310 311 312 313
/*
 * The following structs are for those who like to implement new bus drivers:
 * i2c_algorithm is the interface to a class of hardware solutions which can
 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
 * to name two of the most common.
 */
struct i2c_algorithm {
	/* If an adapter algorithm can't do I2C-level access, set master_xfer
David Brownell's avatar
David Brownell committed
314
	   to NULL. If an adapter algorithm can do SMBus access, set
Linus Torvalds's avatar
Linus Torvalds committed
315 316
	   smbus_xfer. If set to NULL, the SMBus protocol is simulated
	   using common I2C messages */
317 318
	/* master_xfer should return the number of messages successfully
	   processed, or a negative value on error */
Jean Delvare's avatar
Jean Delvare committed
319 320
	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
			   int num);
David Brownell's avatar
David Brownell committed
321
	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
Jean Delvare's avatar
Jean Delvare committed
322 323
			   unsigned short flags, char read_write,
			   u8 command, int size, union i2c_smbus_data *data);
Linus Torvalds's avatar
Linus Torvalds committed
324 325 326 327 328 329 330 331 332 333 334

	/* To determine what the adapter supports */
	u32 (*functionality) (struct i2c_adapter *);
};

/*
 * i2c_adapter is the structure used to identify a physical i2c bus along
 * with the access algorithms necessary to access it.
 */
struct i2c_adapter {
	struct module *owner;
335
	unsigned int id;
336
	unsigned int class;		  /* classes to allow probing for */
337
	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
Linus Torvalds's avatar
Linus Torvalds committed
338 339 340
	void *algo_data;

	/* data fields that are valid for all devices	*/
341
	struct rt_mutex bus_lock;
Linus Torvalds's avatar
Linus Torvalds committed
342

343
	int timeout;			/* in jiffies */
Linus Torvalds's avatar
Linus Torvalds committed
344 345 346 347
	int retries;
	struct device dev;		/* the adapter device */

	int nr;
David Brownell's avatar
David Brownell committed
348
	char name[48];
Linus Torvalds's avatar
Linus Torvalds committed
349 350
	struct completion dev_released;
};
351
#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
Linus Torvalds's avatar
Linus Torvalds committed
352

353
static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
Linus Torvalds's avatar
Linus Torvalds committed
354
{
Jean Delvare's avatar
Jean Delvare committed
355
	return dev_get_drvdata(&dev->dev);
Linus Torvalds's avatar
Linus Torvalds committed
356 357
}

Jean Delvare's avatar
Jean Delvare committed
358
static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
Linus Torvalds's avatar
Linus Torvalds committed
359
{
Jean Delvare's avatar
Jean Delvare committed
360
	dev_set_drvdata(&dev->dev, data);
Linus Torvalds's avatar
Linus Torvalds committed
361 362
}

363 364 365 366 367 368
/**
 * i2c_lock_adapter - Prevent access to an I2C bus segment
 * @adapter: Target I2C bus segment
 */
static inline void i2c_lock_adapter(struct i2c_adapter *adapter)
{
369
	rt_mutex_lock(&adapter->bus_lock);
370 371 372 373 374 375 376 377
}

/**
 * i2c_unlock_adapter - Reauthorize access to an I2C bus segment
 * @adapter: Target I2C bus segment
 */
static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
{
378
	rt_mutex_unlock(&adapter->bus_lock);
379 380
}

Linus Torvalds's avatar
Linus Torvalds committed
381
/*flags for the client struct: */
382 383 384 385
#define I2C_CLIENT_PEC	0x04		/* Use Packet Error Checking */
#define I2C_CLIENT_TEN	0x10		/* we have a ten bit chip address */
					/* Must equal I2C_M_TEN below */
#define I2C_CLIENT_WAKE	0x80		/* for board_info; true iff can wake */
Linus Torvalds's avatar
Linus Torvalds committed
386 387 388 389 390

/* i2c adapter classes (bitmask) */
#define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
#define I2C_CLASS_TV_ANALOG	(1<<1)	/* bttv + friends */
#define I2C_CLASS_TV_DIGITAL	(1<<2)	/* dvb cards */
391
#define I2C_CLASS_DDC		(1<<3)	/* DDC bus on graphics adapters */
392
#define I2C_CLASS_SPD		(1<<7)	/* SPD EEPROMs and similar */
Linus Torvalds's avatar
Linus Torvalds committed
393 394 395 396 397 398 399

/* Internal numbers to terminate lists */
#define I2C_CLIENT_END		0xfffeU

/* The numbers to use to set I2C bus address */
#define ANY_I2C_BUS		0xffff

400 401 402 403
/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
#define I2C_ADDRS(addr, addrs...) \
	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })

Linus Torvalds's avatar
Linus Torvalds committed
404 405 406 407 408

/* ----- functions exported by i2c.o */

/* administration...
 */
409
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
Linus Torvalds's avatar
Linus Torvalds committed
410 411
extern int i2c_add_adapter(struct i2c_adapter *);
extern int i2c_del_adapter(struct i2c_adapter *);
412
extern int i2c_add_numbered_adapter(struct i2c_adapter *);
Linus Torvalds's avatar
Linus Torvalds committed
413

414
extern int i2c_register_driver(struct module *, struct i2c_driver *);
415
extern void i2c_del_driver(struct i2c_driver *);
Linus Torvalds's avatar
Linus Torvalds committed
416

417 418 419 420 421
static inline int i2c_add_driver(struct i2c_driver *driver)
{
	return i2c_register_driver(THIS_MODULE, driver);
}

422 423
extern struct i2c_client *i2c_use_client(struct i2c_client *client);
extern void i2c_release_client(struct i2c_client *client);
Linus Torvalds's avatar
Linus Torvalds committed
424 425 426 427 428 429

/* call the i2c_client->command() of all attached clients with
 * the given arguments */
extern void i2c_clients_command(struct i2c_adapter *adap,
				unsigned int cmd, void *arg);

Jean Delvare's avatar
Jean Delvare committed
430
extern struct i2c_adapter *i2c_get_adapter(int id);
Linus Torvalds's avatar
Linus Torvalds committed
431 432 433 434 435 436 437 438 439 440 441 442 443 444 445
extern void i2c_put_adapter(struct i2c_adapter *adap);


/* Return the functionality mask */
static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
{
	return adap->algo->functionality(adap);
}

/* Return 1 if adapter supports everything we need, 0 if not. */
static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
{
	return (func & i2c_get_functionality(adap)) == func;
}

Jean Delvare's avatar
Jean Delvare committed
446
/* Return the adapter number for a specific adapter */
447 448 449 450
static inline int i2c_adapter_id(struct i2c_adapter *adap)
{
	return adap->nr;
}
451
#endif /* I2C */
452
#endif /* __KERNEL__ */
453

David Brownell's avatar
David Brownell committed
454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488
/**
 * struct i2c_msg - an I2C transaction segment beginning with START
 * @addr: Slave address, either seven or ten bits.  When this is a ten
 *	bit address, I2C_M_TEN must be set in @flags and the adapter
 *	must support I2C_FUNC_10BIT_ADDR.
 * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
 *	provided unless the adapter exported the relevant I2C_FUNC_*
 *	flags through i2c_check_functionality().
 * @len: Number of data bytes in @buf being read from or written to the
 *	I2C slave address.  For read transactions where I2C_M_RECV_LEN
 *	is set, the caller guarantees that this buffer can hold up to
 *	32 bytes in addition to the initial length byte sent by the
 *	slave (plus, if used, the SMBus PEC); and this value will be
 *	incremented by the number of block data bytes received.
 * @buf: The buffer into which data is read, or from which it's written.
 *
 * An i2c_msg is the low level representation of one segment of an I2C
 * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
 * to userspace from i2c-dev, and to I2C adapter drivers through the
 * @i2c_adapter.@master_xfer() method.
 *
 * Except when I2C "protocol mangling" is used, all I2C adapters implement
 * the standard rules for I2C transactions.  Each transaction begins with a
 * START.  That is followed by the slave address, and a bit encoding read
 * versus write.  Then follow all the data bytes, possibly including a byte
 * with SMBus PEC.  The transfer terminates with a NAK, or when all those
 * bytes have been transferred and ACKed.  If this is the last message in a
 * group, it is followed by a STOP.  Otherwise it is followed by the next
 * @i2c_msg transaction segment, beginning with a (repeated) START.
 *
 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
 * passing certain @flags may have changed those standard protocol behaviors.
 * Those flags are only for use with broken/nonconforming slaves, and with
 * adapters which are known to support the specific mangling options they
 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
Linus Torvalds's avatar
Linus Torvalds committed
489 490 491
 */
struct i2c_msg {
	__u16 addr;	/* slave address			*/
David Brownell's avatar
David Brownell committed
492
	__u16 flags;
David Brownell's avatar
David Brownell committed
493 494 495 496 497 498 499
#define I2C_M_TEN		0x0010	/* this is a ten bit chip address */
#define I2C_M_RD		0x0001	/* read data, from slave to master */
#define I2C_M_NOSTART		0x4000	/* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_REV_DIR_ADDR	0x2000	/* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_IGNORE_NAK	0x1000	/* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_NO_RD_ACK		0x0800	/* if I2C_FUNC_PROTOCOL_MANGLING */
#define I2C_M_RECV_LEN		0x0400	/* length will be first received byte */
David Brownell's avatar
David Brownell committed
500 501
	__u16 len;		/* msg length				*/
	__u8 *buf;		/* pointer to msg data			*/
Linus Torvalds's avatar
Linus Torvalds committed
502 503 504 505 506 507
};

/* To determine what functionality is present */

#define I2C_FUNC_I2C			0x00000001
#define I2C_FUNC_10BIT_ADDR		0x00000002
Jean Delvare's avatar
Jean Delvare committed
508
#define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_NOSTART etc. */
509
#define I2C_FUNC_SMBUS_PEC		0x00000008
Linus Torvalds's avatar
Linus Torvalds committed
510
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
David Brownell's avatar
David Brownell committed
511 512 513 514 515 516 517 518 519 520
#define I2C_FUNC_SMBUS_QUICK		0x00010000
#define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
#define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000
#define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000
#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000
#define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000
#define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000
#define I2C_FUNC_SMBUS_PROC_CALL	0x00800000
#define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000
#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
Linus Torvalds's avatar
Linus Torvalds committed
521 522 523
#define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */

Jean Delvare's avatar
Jean Delvare committed
524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542
#define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
					 I2C_FUNC_SMBUS_WRITE_BYTE)
#define I2C_FUNC_SMBUS_BYTE_DATA	(I2C_FUNC_SMBUS_READ_BYTE_DATA | \
					 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
#define I2C_FUNC_SMBUS_WORD_DATA	(I2C_FUNC_SMBUS_READ_WORD_DATA | \
					 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
#define I2C_FUNC_SMBUS_BLOCK_DATA	(I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
#define I2C_FUNC_SMBUS_I2C_BLOCK	(I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
					 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)

#define I2C_FUNC_SMBUS_EMUL		(I2C_FUNC_SMBUS_QUICK | \
					 I2C_FUNC_SMBUS_BYTE | \
					 I2C_FUNC_SMBUS_BYTE_DATA | \
					 I2C_FUNC_SMBUS_WORD_DATA | \
					 I2C_FUNC_SMBUS_PROC_CALL | \
					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
					 I2C_FUNC_SMBUS_I2C_BLOCK | \
					 I2C_FUNC_SMBUS_PEC)
Linus Torvalds's avatar
Linus Torvalds committed
543

David Brownell's avatar
David Brownell committed
544 545
/*
 * Data for SMBus Messages
Linus Torvalds's avatar
Linus Torvalds committed
546
 */
David Brownell's avatar
David Brownell committed
547
#define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */
Linus Torvalds's avatar
Linus Torvalds committed
548 549 550
union i2c_smbus_data {
	__u8 byte;
	__u16 word;
551
	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
Jean Delvare's avatar
Jean Delvare committed
552
			       /* and one more for user-space compatibility */
Linus Torvalds's avatar
Linus Torvalds committed
553 554
};

555
/* i2c_smbus_xfer read or write markers */
Linus Torvalds's avatar
Linus Torvalds committed
556 557 558
#define I2C_SMBUS_READ	1
#define I2C_SMBUS_WRITE	0

David Brownell's avatar
David Brownell committed
559
/* SMBus transaction types (size parameter in the above functions)
Linus Torvalds's avatar
Linus Torvalds committed
560 561 562
   Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
#define I2C_SMBUS_QUICK		    0
#define I2C_SMBUS_BYTE		    1
David Brownell's avatar
David Brownell committed
563
#define I2C_SMBUS_BYTE_DATA	    2
Linus Torvalds's avatar
Linus Torvalds committed
564 565 566
#define I2C_SMBUS_WORD_DATA	    3
#define I2C_SMBUS_PROC_CALL	    4
#define I2C_SMBUS_BLOCK_DATA	    5
567
#define I2C_SMBUS_I2C_BLOCK_BROKEN  6
Linus Torvalds's avatar
Linus Torvalds committed
568
#define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */
569
#define I2C_SMBUS_I2C_BLOCK_DATA    8
Linus Torvalds's avatar
Linus Torvalds committed
570 571


572
#ifdef __KERNEL__
Linus Torvalds's avatar
Linus Torvalds committed
573 574 575 576 577 578 579

/* These defines are used for probing i2c client addresses */
/* The length of the option lists */
#define I2C_CLIENT_MAX_OPTS 48

/* Default fill of many variables */
#define I2C_CLIENT_DEFAULTS {I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
Jean Delvare's avatar
Jean Delvare committed
580 581 582 583 584 585 586 587 588 589 590 591 592 593 594
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END, \
			     I2C_CLIENT_END, I2C_CLIENT_END, I2C_CLIENT_END}
Linus Torvalds's avatar
Linus Torvalds committed
595 596 597 598 599 600 601 602

/* I2C_CLIENT_MODULE_PARM creates a module parameter, and puts it in the
   module header */

#define I2C_CLIENT_MODULE_PARM(var,desc) \
  static unsigned short var[I2C_CLIENT_MAX_OPTS] = I2C_CLIENT_DEFAULTS; \
  static unsigned int var##_num; \
  module_param_array(var, short, &var##_num, 0); \
Jean Delvare's avatar
Jean Delvare committed
603
  MODULE_PARM_DESC(var, desc)
Linus Torvalds's avatar
Linus Torvalds committed
604

605
#endif /* __KERNEL__ */
Linus Torvalds's avatar
Linus Torvalds committed
606
#endif /* _LINUX_I2C_H */