xref: /linux-6.15/include/linux/i2c.h (revision 5bf2b193)
1 /* ------------------------------------------------------------------------- */
2 /*									     */
3 /* i2c.h - definitions for the i2c-bus interface			     */
4 /*									     */
5 /* ------------------------------------------------------------------------- */
6 /*   Copyright (C) 1995-2000 Simon G. Vogl
7 
8     This program is free software; you can redistribute it and/or modify
9     it under the terms of the GNU General Public License as published by
10     the Free Software Foundation; either version 2 of the License, or
11     (at your option) any later version.
12 
13     This program is distributed in the hope that it will be useful,
14     but WITHOUT ANY WARRANTY; without even the implied warranty of
15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16     GNU General Public License for more details.
17 
18     You should have received a copy of the GNU General Public License
19     along with this program; if not, write to the Free Software
20     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     */
21 /* ------------------------------------------------------------------------- */
22 
23 /* With some changes from Kyösti Mälkki <[email protected]> and
24    Frodo Looijaard <[email protected]> */
25 
26 #ifndef _LINUX_I2C_H
27 #define _LINUX_I2C_H
28 
29 #include <linux/types.h>
30 #ifdef __KERNEL__
31 #include <linux/module.h>
32 #include <linux/i2c-id.h>
33 #include <linux/mod_devicetable.h>
34 #include <linux/device.h>	/* for struct device */
35 #include <linux/sched.h>	/* for completion */
36 #include <linux/mutex.h>
37 #include <linux/of.h>		/* for struct device_node */
38 
39 extern struct bus_type i2c_bus_type;
40 
41 /* --- General options ------------------------------------------------	*/
42 
43 struct i2c_msg;
44 struct i2c_algorithm;
45 struct i2c_adapter;
46 struct i2c_client;
47 struct i2c_driver;
48 union i2c_smbus_data;
49 struct i2c_board_info;
50 
51 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
52 /*
53  * The master routines are the ones normally used to transmit data to devices
54  * on a bus (or read from them). Apart from two basic transfer functions to
55  * transmit one message at a time, a more complex version can be used to
56  * transmit an arbitrary number of messages without interruption.
57  * @count must be be less than 64k since msg.len is u16.
58  */
59 extern int i2c_master_send(struct i2c_client *client, const char *buf,
60 			   int count);
61 extern int i2c_master_recv(struct i2c_client *client, char *buf, int count);
62 
63 /* Transfer num messages.
64  */
65 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
66 			int num);
67 
68 /* This is the very generalized SMBus access routine. You probably do not
69    want to use this, though; one of the functions below may be much easier,
70    and probably just as fast.
71    Note that we use i2c_adapter here, because you do not need a specific
72    smbus adapter to call this function. */
73 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
74 			  unsigned short flags, char read_write, u8 command,
75 			  int size, union i2c_smbus_data *data);
76 
77 /* Now follow the 'nice' access routines. These also document the calling
78    conventions of i2c_smbus_xfer. */
79 
80 extern s32 i2c_smbus_read_byte(struct i2c_client *client);
81 extern s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value);
82 extern s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command);
83 extern s32 i2c_smbus_write_byte_data(struct i2c_client *client,
84 				     u8 command, u8 value);
85 extern s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command);
86 extern s32 i2c_smbus_write_word_data(struct i2c_client *client,
87 				     u8 command, u16 value);
88 /* Returns the number of read bytes */
89 extern s32 i2c_smbus_read_block_data(struct i2c_client *client,
90 				     u8 command, u8 *values);
91 extern s32 i2c_smbus_write_block_data(struct i2c_client *client,
92 				      u8 command, u8 length, const u8 *values);
93 /* Returns the number of read bytes */
94 extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client,
95 					 u8 command, u8 length, u8 *values);
96 extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
97 					  u8 command, u8 length,
98 					  const u8 *values);
99 #endif /* I2C */
100 
101 /**
102  * struct i2c_driver - represent an I2C device driver
103  * @class: What kind of i2c device we instantiate (for detect)
104  * @attach_adapter: Callback for bus addition (for legacy drivers)
105  * @detach_adapter: Callback for bus removal (for legacy drivers)
106  * @probe: Callback for device binding
107  * @remove: Callback for device unbinding
108  * @shutdown: Callback for device shutdown
109  * @suspend: Callback for device suspend
110  * @resume: Callback for device resume
111  * @alert: Alert callback, for example for the SMBus alert protocol
112  * @command: Callback for bus-wide signaling (optional)
113  * @driver: Device driver model driver
114  * @id_table: List of I2C devices supported by this driver
115  * @detect: Callback for device detection
116  * @address_list: The I2C addresses to probe (for detect)
117  * @clients: List of detected clients we created (for i2c-core use only)
118  *
119  * The driver.owner field should be set to the module owner of this driver.
120  * The driver.name field should be set to the name of this driver.
121  *
122  * For automatic device detection, both @detect and @address_data must
123  * be defined. @class should also be set, otherwise only devices forced
124  * with module parameters will be created. The detect function must
125  * fill at least the name field of the i2c_board_info structure it is
126  * handed upon successful detection, and possibly also the flags field.
127  *
128  * If @detect is missing, the driver will still work fine for enumerated
129  * devices. Detected devices simply won't be supported. This is expected
130  * for the many I2C/SMBus devices which can't be detected reliably, and
131  * the ones which can always be enumerated in practice.
132  *
133  * The i2c_client structure which is handed to the @detect callback is
134  * not a real i2c_client. It is initialized just enough so that you can
135  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
136  * else with it. In particular, calling dev_dbg and friends on it is
137  * not allowed.
138  */
139 struct i2c_driver {
140 	unsigned int class;
141 
142 	/* Notifies the driver that a new bus has appeared or is about to be
143 	 * removed. You should avoid using this if you can, it will probably
144 	 * be removed in a near future.
145 	 */
146 	int (*attach_adapter)(struct i2c_adapter *);
147 	int (*detach_adapter)(struct i2c_adapter *);
148 
149 	/* Standard driver model interfaces */
150 	int (*probe)(struct i2c_client *, const struct i2c_device_id *);
151 	int (*remove)(struct i2c_client *);
152 
153 	/* driver model interfaces that don't relate to enumeration  */
154 	void (*shutdown)(struct i2c_client *);
155 	int (*suspend)(struct i2c_client *, pm_message_t mesg);
156 	int (*resume)(struct i2c_client *);
157 
158 	/* Alert callback, for example for the SMBus alert protocol.
159 	 * The format and meaning of the data value depends on the protocol.
160 	 * For the SMBus alert protocol, there is a single bit of data passed
161 	 * as the alert response's low bit ("event flag").
162 	 */
163 	void (*alert)(struct i2c_client *, unsigned int data);
164 
165 	/* a ioctl like command that can be used to perform specific functions
166 	 * with the device.
167 	 */
168 	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
169 
170 	struct device_driver driver;
171 	const struct i2c_device_id *id_table;
172 
173 	/* Device detection callback for automatic device creation */
174 	int (*detect)(struct i2c_client *, struct i2c_board_info *);
175 	const unsigned short *address_list;
176 	struct list_head clients;
177 };
178 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
179 
180 /**
181  * struct i2c_client - represent an I2C slave device
182  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
183  *	I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
184  * @addr: Address used on the I2C bus connected to the parent adapter.
185  * @name: Indicates the type of the device, usually a chip name that's
186  *	generic enough to hide second-sourcing and compatible revisions.
187  * @adapter: manages the bus segment hosting this I2C device
188  * @driver: device's driver, hence pointer to access routines
189  * @dev: Driver model device node for the slave.
190  * @irq: indicates the IRQ generated by this device (if any)
191  * @detected: member of an i2c_driver.clients list or i2c-core's
192  *	userspace_devices list
193  *
194  * An i2c_client identifies a single device (i.e. chip) connected to an
195  * i2c bus. The behaviour exposed to Linux is defined by the driver
196  * managing the device.
197  */
198 struct i2c_client {
199 	unsigned short flags;		/* div., see below		*/
200 	unsigned short addr;		/* chip address - NOTE: 7bit	*/
201 					/* addresses are stored in the	*/
202 					/* _LOWER_ 7 bits		*/
203 	char name[I2C_NAME_SIZE];
204 	struct i2c_adapter *adapter;	/* the adapter we sit on	*/
205 	struct i2c_driver *driver;	/* and our access routines	*/
206 	struct device dev;		/* the device structure		*/
207 	int irq;			/* irq issued by device		*/
208 	struct list_head detected;
209 };
210 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
211 
212 extern struct i2c_client *i2c_verify_client(struct device *dev);
213 
214 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
215 {
216 	struct device * const dev = container_of(kobj, struct device, kobj);
217 	return to_i2c_client(dev);
218 }
219 
220 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
221 {
222 	return dev_get_drvdata(&dev->dev);
223 }
224 
225 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
226 {
227 	dev_set_drvdata(&dev->dev, data);
228 }
229 
230 /**
231  * struct i2c_board_info - template for device creation
232  * @type: chip type, to initialize i2c_client.name
233  * @flags: to initialize i2c_client.flags
234  * @addr: stored in i2c_client.addr
235  * @platform_data: stored in i2c_client.dev.platform_data
236  * @archdata: copied into i2c_client.dev.archdata
237  * @of_node: pointer to OpenFirmware device node
238  * @irq: stored in i2c_client.irq
239  *
240  * I2C doesn't actually support hardware probing, although controllers and
241  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
242  * a device at a given address.  Drivers commonly need more information than
243  * that, such as chip type, configuration, associated IRQ, and so on.
244  *
245  * i2c_board_info is used to build tables of information listing I2C devices
246  * that are present.  This information is used to grow the driver model tree.
247  * For mainboards this is done statically using i2c_register_board_info();
248  * bus numbers identify adapters that aren't yet available.  For add-on boards,
249  * i2c_new_device() does this dynamically with the adapter already known.
250  */
251 struct i2c_board_info {
252 	char		type[I2C_NAME_SIZE];
253 	unsigned short	flags;
254 	unsigned short	addr;
255 	void		*platform_data;
256 	struct dev_archdata	*archdata;
257 #ifdef CONFIG_OF
258 	struct device_node *of_node;
259 #endif
260 	int		irq;
261 };
262 
263 /**
264  * I2C_BOARD_INFO - macro used to list an i2c device and its address
265  * @dev_type: identifies the device type
266  * @dev_addr: the device's address on the bus.
267  *
268  * This macro initializes essential fields of a struct i2c_board_info,
269  * declaring what has been provided on a particular board.  Optional
270  * fields (such as associated irq, or device-specific platform_data)
271  * are provided using conventional syntax.
272  */
273 #define I2C_BOARD_INFO(dev_type, dev_addr) \
274 	.type = dev_type, .addr = (dev_addr)
275 
276 
277 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
278 /* Add-on boards should register/unregister their devices; e.g. a board
279  * with integrated I2C, a config eeprom, sensors, and a codec that's
280  * used in conjunction with the primary hardware.
281  */
282 extern struct i2c_client *
283 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
284 
285 /* If you don't know the exact address of an I2C device, use this variant
286  * instead, which can probe for device presence in a list of possible
287  * addresses.
288  */
289 extern struct i2c_client *
290 i2c_new_probed_device(struct i2c_adapter *adap,
291 		      struct i2c_board_info *info,
292 		      unsigned short const *addr_list);
293 
294 /* For devices that use several addresses, use i2c_new_dummy() to make
295  * client handles for the extra addresses.
296  */
297 extern struct i2c_client *
298 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
299 
300 extern void i2c_unregister_device(struct i2c_client *);
301 #endif /* I2C */
302 
303 /* Mainboard arch_initcall() code should register all its I2C devices.
304  * This is done at arch_initcall time, before declaring any i2c adapters.
305  * Modules for add-on boards must use other calls.
306  */
307 #ifdef CONFIG_I2C_BOARDINFO
308 extern int
309 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
310 			unsigned n);
311 #else
312 static inline int
313 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
314 			unsigned n)
315 {
316 	return 0;
317 }
318 #endif /* I2C_BOARDINFO */
319 
320 /*
321  * The following structs are for those who like to implement new bus drivers:
322  * i2c_algorithm is the interface to a class of hardware solutions which can
323  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
324  * to name two of the most common.
325  */
326 struct i2c_algorithm {
327 	/* If an adapter algorithm can't do I2C-level access, set master_xfer
328 	   to NULL. If an adapter algorithm can do SMBus access, set
329 	   smbus_xfer. If set to NULL, the SMBus protocol is simulated
330 	   using common I2C messages */
331 	/* master_xfer should return the number of messages successfully
332 	   processed, or a negative value on error */
333 	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
334 			   int num);
335 	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
336 			   unsigned short flags, char read_write,
337 			   u8 command, int size, union i2c_smbus_data *data);
338 
339 	/* To determine what the adapter supports */
340 	u32 (*functionality) (struct i2c_adapter *);
341 };
342 
343 /*
344  * i2c_adapter is the structure used to identify a physical i2c bus along
345  * with the access algorithms necessary to access it.
346  */
347 struct i2c_adapter {
348 	struct module *owner;
349 	unsigned int id;
350 	unsigned int class;		  /* classes to allow probing for */
351 	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
352 	void *algo_data;
353 
354 	/* data fields that are valid for all devices	*/
355 	struct rt_mutex bus_lock;
356 
357 	int timeout;			/* in jiffies */
358 	int retries;
359 	struct device dev;		/* the adapter device */
360 
361 	int nr;
362 	char name[48];
363 	struct completion dev_released;
364 
365 	struct list_head userspace_clients;
366 };
367 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
368 
369 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
370 {
371 	return dev_get_drvdata(&dev->dev);
372 }
373 
374 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
375 {
376 	dev_set_drvdata(&dev->dev, data);
377 }
378 
379 /**
380  * i2c_lock_adapter - Prevent access to an I2C bus segment
381  * @adapter: Target I2C bus segment
382  */
383 static inline void i2c_lock_adapter(struct i2c_adapter *adapter)
384 {
385 	rt_mutex_lock(&adapter->bus_lock);
386 }
387 
388 /**
389  * i2c_unlock_adapter - Reauthorize access to an I2C bus segment
390  * @adapter: Target I2C bus segment
391  */
392 static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
393 {
394 	rt_mutex_unlock(&adapter->bus_lock);
395 }
396 
397 /*flags for the client struct: */
398 #define I2C_CLIENT_PEC	0x04		/* Use Packet Error Checking */
399 #define I2C_CLIENT_TEN	0x10		/* we have a ten bit chip address */
400 					/* Must equal I2C_M_TEN below */
401 #define I2C_CLIENT_WAKE	0x80		/* for board_info; true iff can wake */
402 
403 /* i2c adapter classes (bitmask) */
404 #define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
405 #define I2C_CLASS_TV_ANALOG	(1<<1)	/* bttv + friends */
406 #define I2C_CLASS_TV_DIGITAL	(1<<2)	/* dvb cards */
407 #define I2C_CLASS_DDC		(1<<3)	/* DDC bus on graphics adapters */
408 #define I2C_CLASS_SPD		(1<<7)	/* SPD EEPROMs and similar */
409 
410 /* Internal numbers to terminate lists */
411 #define I2C_CLIENT_END		0xfffeU
412 
413 /* The numbers to use to set I2C bus address */
414 #define ANY_I2C_BUS		0xffff
415 
416 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
417 #define I2C_ADDRS(addr, addrs...) \
418 	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
419 
420 
421 /* ----- functions exported by i2c.o */
422 
423 /* administration...
424  */
425 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
426 extern int i2c_add_adapter(struct i2c_adapter *);
427 extern int i2c_del_adapter(struct i2c_adapter *);
428 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
429 
430 extern int i2c_register_driver(struct module *, struct i2c_driver *);
431 extern void i2c_del_driver(struct i2c_driver *);
432 
433 static inline int i2c_add_driver(struct i2c_driver *driver)
434 {
435 	return i2c_register_driver(THIS_MODULE, driver);
436 }
437 
438 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
439 extern void i2c_release_client(struct i2c_client *client);
440 
441 /* call the i2c_client->command() of all attached clients with
442  * the given arguments */
443 extern void i2c_clients_command(struct i2c_adapter *adap,
444 				unsigned int cmd, void *arg);
445 
446 extern struct i2c_adapter *i2c_get_adapter(int id);
447 extern void i2c_put_adapter(struct i2c_adapter *adap);
448 
449 
450 /* Return the functionality mask */
451 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
452 {
453 	return adap->algo->functionality(adap);
454 }
455 
456 /* Return 1 if adapter supports everything we need, 0 if not. */
457 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
458 {
459 	return (func & i2c_get_functionality(adap)) == func;
460 }
461 
462 /* Return the adapter number for a specific adapter */
463 static inline int i2c_adapter_id(struct i2c_adapter *adap)
464 {
465 	return adap->nr;
466 }
467 #endif /* I2C */
468 #endif /* __KERNEL__ */
469 
470 /**
471  * struct i2c_msg - an I2C transaction segment beginning with START
472  * @addr: Slave address, either seven or ten bits.  When this is a ten
473  *	bit address, I2C_M_TEN must be set in @flags and the adapter
474  *	must support I2C_FUNC_10BIT_ADDR.
475  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
476  *	provided unless the adapter exported the relevant I2C_FUNC_*
477  *	flags through i2c_check_functionality().
478  * @len: Number of data bytes in @buf being read from or written to the
479  *	I2C slave address.  For read transactions where I2C_M_RECV_LEN
480  *	is set, the caller guarantees that this buffer can hold up to
481  *	32 bytes in addition to the initial length byte sent by the
482  *	slave (plus, if used, the SMBus PEC); and this value will be
483  *	incremented by the number of block data bytes received.
484  * @buf: The buffer into which data is read, or from which it's written.
485  *
486  * An i2c_msg is the low level representation of one segment of an I2C
487  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
488  * to userspace from i2c-dev, and to I2C adapter drivers through the
489  * @i2c_adapter.@master_xfer() method.
490  *
491  * Except when I2C "protocol mangling" is used, all I2C adapters implement
492  * the standard rules for I2C transactions.  Each transaction begins with a
493  * START.  That is followed by the slave address, and a bit encoding read
494  * versus write.  Then follow all the data bytes, possibly including a byte
495  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
496  * bytes have been transferred and ACKed.  If this is the last message in a
497  * group, it is followed by a STOP.  Otherwise it is followed by the next
498  * @i2c_msg transaction segment, beginning with a (repeated) START.
499  *
500  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
501  * passing certain @flags may have changed those standard protocol behaviors.
502  * Those flags are only for use with broken/nonconforming slaves, and with
503  * adapters which are known to support the specific mangling options they
504  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
505  */
506 struct i2c_msg {
507 	__u16 addr;	/* slave address			*/
508 	__u16 flags;
509 #define I2C_M_TEN		0x0010	/* this is a ten bit chip address */
510 #define I2C_M_RD		0x0001	/* read data, from slave to master */
511 #define I2C_M_NOSTART		0x4000	/* if I2C_FUNC_PROTOCOL_MANGLING */
512 #define I2C_M_REV_DIR_ADDR	0x2000	/* if I2C_FUNC_PROTOCOL_MANGLING */
513 #define I2C_M_IGNORE_NAK	0x1000	/* if I2C_FUNC_PROTOCOL_MANGLING */
514 #define I2C_M_NO_RD_ACK		0x0800	/* if I2C_FUNC_PROTOCOL_MANGLING */
515 #define I2C_M_RECV_LEN		0x0400	/* length will be first received byte */
516 	__u16 len;		/* msg length				*/
517 	__u8 *buf;		/* pointer to msg data			*/
518 };
519 
520 /* To determine what functionality is present */
521 
522 #define I2C_FUNC_I2C			0x00000001
523 #define I2C_FUNC_10BIT_ADDR		0x00000002
524 #define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_NOSTART etc. */
525 #define I2C_FUNC_SMBUS_PEC		0x00000008
526 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
527 #define I2C_FUNC_SMBUS_QUICK		0x00010000
528 #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
529 #define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000
530 #define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000
531 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000
532 #define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000
533 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000
534 #define I2C_FUNC_SMBUS_PROC_CALL	0x00800000
535 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000
536 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
537 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
538 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */
539 
540 #define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
541 					 I2C_FUNC_SMBUS_WRITE_BYTE)
542 #define I2C_FUNC_SMBUS_BYTE_DATA	(I2C_FUNC_SMBUS_READ_BYTE_DATA | \
543 					 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
544 #define I2C_FUNC_SMBUS_WORD_DATA	(I2C_FUNC_SMBUS_READ_WORD_DATA | \
545 					 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
546 #define I2C_FUNC_SMBUS_BLOCK_DATA	(I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
547 					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
548 #define I2C_FUNC_SMBUS_I2C_BLOCK	(I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
549 					 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
550 
551 #define I2C_FUNC_SMBUS_EMUL		(I2C_FUNC_SMBUS_QUICK | \
552 					 I2C_FUNC_SMBUS_BYTE | \
553 					 I2C_FUNC_SMBUS_BYTE_DATA | \
554 					 I2C_FUNC_SMBUS_WORD_DATA | \
555 					 I2C_FUNC_SMBUS_PROC_CALL | \
556 					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
557 					 I2C_FUNC_SMBUS_I2C_BLOCK | \
558 					 I2C_FUNC_SMBUS_PEC)
559 
560 /*
561  * Data for SMBus Messages
562  */
563 #define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */
564 union i2c_smbus_data {
565 	__u8 byte;
566 	__u16 word;
567 	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
568 			       /* and one more for user-space compatibility */
569 };
570 
571 /* i2c_smbus_xfer read or write markers */
572 #define I2C_SMBUS_READ	1
573 #define I2C_SMBUS_WRITE	0
574 
575 /* SMBus transaction types (size parameter in the above functions)
576    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
577 #define I2C_SMBUS_QUICK		    0
578 #define I2C_SMBUS_BYTE		    1
579 #define I2C_SMBUS_BYTE_DATA	    2
580 #define I2C_SMBUS_WORD_DATA	    3
581 #define I2C_SMBUS_PROC_CALL	    4
582 #define I2C_SMBUS_BLOCK_DATA	    5
583 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
584 #define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */
585 #define I2C_SMBUS_I2C_BLOCK_DATA    8
586 
587 #endif /* _LINUX_I2C_H */
588