xref: /openbmc/linux/include/linux/i2c.h (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 <kmalkki@cc.hut.fi> and
24    Frodo Looijaard <frodol@dds.nl> */
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 extern struct device_type i2c_adapter_type;
41 
42 /* --- General options ------------------------------------------------	*/
43 
44 struct i2c_msg;
45 struct i2c_algorithm;
46 struct i2c_adapter;
47 struct i2c_client;
48 struct i2c_driver;
49 union i2c_smbus_data;
50 struct i2c_board_info;
51 
52 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
53 /*
54  * The master routines are the ones normally used to transmit data to devices
55  * on a bus (or read from them). Apart from two basic transfer functions to
56  * transmit one message at a time, a more complex version can be used to
57  * transmit an arbitrary number of messages without interruption.
58  * @count must be be less than 64k since msg.len is u16.
59  */
60 extern int i2c_master_send(struct i2c_client *client, const char *buf,
61 			   int count);
62 extern int i2c_master_recv(struct i2c_client *client, char *buf, int count);
63 
64 /* Transfer num messages.
65  */
66 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
67 			int num);
68 
69 /* This is the very generalized SMBus access routine. You probably do not
70    want to use this, though; one of the functions below may be much easier,
71    and probably just as fast.
72    Note that we use i2c_adapter here, because you do not need a specific
73    smbus adapter to call this function. */
74 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
75 			  unsigned short flags, char read_write, u8 command,
76 			  int size, union i2c_smbus_data *data);
77 
78 /* Now follow the 'nice' access routines. These also document the calling
79    conventions of i2c_smbus_xfer. */
80 
81 extern s32 i2c_smbus_read_byte(struct i2c_client *client);
82 extern s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value);
83 extern s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command);
84 extern s32 i2c_smbus_write_byte_data(struct i2c_client *client,
85 				     u8 command, u8 value);
86 extern s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command);
87 extern s32 i2c_smbus_write_word_data(struct i2c_client *client,
88 				     u8 command, u16 value);
89 /* Returns the number of read bytes */
90 extern s32 i2c_smbus_read_block_data(struct i2c_client *client,
91 				     u8 command, u8 *values);
92 extern s32 i2c_smbus_write_block_data(struct i2c_client *client,
93 				      u8 command, u8 length, const u8 *values);
94 /* Returns the number of read bytes */
95 extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client,
96 					 u8 command, u8 length, u8 *values);
97 extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
98 					  u8 command, u8 length,
99 					  const u8 *values);
100 #endif /* I2C */
101 
102 /**
103  * struct i2c_driver - represent an I2C device driver
104  * @class: What kind of i2c device we instantiate (for detect)
105  * @attach_adapter: Callback for bus addition (for legacy drivers)
106  * @detach_adapter: Callback for bus removal (for legacy drivers)
107  * @probe: Callback for device binding
108  * @remove: Callback for device unbinding
109  * @shutdown: Callback for device shutdown
110  * @suspend: Callback for device suspend
111  * @resume: Callback for device resume
112  * @alert: Alert callback, for example for the SMBus alert protocol
113  * @command: Callback for bus-wide signaling (optional)
114  * @driver: Device driver model driver
115  * @id_table: List of I2C devices supported by this driver
116  * @detect: Callback for device detection
117  * @address_list: The I2C addresses to probe (for detect)
118  * @clients: List of detected clients we created (for i2c-core use only)
119  *
120  * The driver.owner field should be set to the module owner of this driver.
121  * The driver.name field should be set to the name of this driver.
122  *
123  * For automatic device detection, both @detect and @address_data must
124  * be defined. @class should also be set, otherwise only devices forced
125  * with module parameters will be created. The detect function must
126  * fill at least the name field of the i2c_board_info structure it is
127  * handed upon successful detection, and possibly also the flags field.
128  *
129  * If @detect is missing, the driver will still work fine for enumerated
130  * devices. Detected devices simply won't be supported. This is expected
131  * for the many I2C/SMBus devices which can't be detected reliably, and
132  * the ones which can always be enumerated in practice.
133  *
134  * The i2c_client structure which is handed to the @detect callback is
135  * not a real i2c_client. It is initialized just enough so that you can
136  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
137  * else with it. In particular, calling dev_dbg and friends on it is
138  * not allowed.
139  */
140 struct i2c_driver {
141 	unsigned int class;
142 
143 	/* Notifies the driver that a new bus has appeared or is about to be
144 	 * removed. You should avoid using this if you can, it will probably
145 	 * be removed in a near future.
146 	 */
147 	int (*attach_adapter)(struct i2c_adapter *);
148 	int (*detach_adapter)(struct i2c_adapter *);
149 
150 	/* Standard driver model interfaces */
151 	int (*probe)(struct i2c_client *, const struct i2c_device_id *);
152 	int (*remove)(struct i2c_client *);
153 
154 	/* driver model interfaces that don't relate to enumeration  */
155 	void (*shutdown)(struct i2c_client *);
156 	int (*suspend)(struct i2c_client *, pm_message_t mesg);
157 	int (*resume)(struct i2c_client *);
158 
159 	/* Alert callback, for example for the SMBus alert protocol.
160 	 * The format and meaning of the data value depends on the protocol.
161 	 * For the SMBus alert protocol, there is a single bit of data passed
162 	 * as the alert response's low bit ("event flag").
163 	 */
164 	void (*alert)(struct i2c_client *, unsigned int data);
165 
166 	/* a ioctl like command that can be used to perform specific functions
167 	 * with the device.
168 	 */
169 	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
170 
171 	struct device_driver driver;
172 	const struct i2c_device_id *id_table;
173 
174 	/* Device detection callback for automatic device creation */
175 	int (*detect)(struct i2c_client *, struct i2c_board_info *);
176 	const unsigned short *address_list;
177 	struct list_head clients;
178 };
179 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
180 
181 /**
182  * struct i2c_client - represent an I2C slave device
183  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
184  *	I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
185  * @addr: Address used on the I2C bus connected to the parent adapter.
186  * @name: Indicates the type of the device, usually a chip name that's
187  *	generic enough to hide second-sourcing and compatible revisions.
188  * @adapter: manages the bus segment hosting this I2C device
189  * @driver: device's driver, hence pointer to access routines
190  * @dev: Driver model device node for the slave.
191  * @irq: indicates the IRQ generated by this device (if any)
192  * @detected: member of an i2c_driver.clients list or i2c-core's
193  *	userspace_devices list
194  *
195  * An i2c_client identifies a single device (i.e. chip) connected to an
196  * i2c bus. The behaviour exposed to Linux is defined by the driver
197  * managing the device.
198  */
199 struct i2c_client {
200 	unsigned short flags;		/* div., see below		*/
201 	unsigned short addr;		/* chip address - NOTE: 7bit	*/
202 					/* addresses are stored in the	*/
203 					/* _LOWER_ 7 bits		*/
204 	char name[I2C_NAME_SIZE];
205 	struct i2c_adapter *adapter;	/* the adapter we sit on	*/
206 	struct i2c_driver *driver;	/* and our access routines	*/
207 	struct device dev;		/* the device structure		*/
208 	int irq;			/* irq issued by device		*/
209 	struct list_head detected;
210 };
211 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
212 
213 extern struct i2c_client *i2c_verify_client(struct device *dev);
214 
215 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
216 {
217 	struct device * const dev = container_of(kobj, struct device, kobj);
218 	return to_i2c_client(dev);
219 }
220 
221 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
222 {
223 	return dev_get_drvdata(&dev->dev);
224 }
225 
226 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
227 {
228 	dev_set_drvdata(&dev->dev, data);
229 }
230 
231 /**
232  * struct i2c_board_info - template for device creation
233  * @type: chip type, to initialize i2c_client.name
234  * @flags: to initialize i2c_client.flags
235  * @addr: stored in i2c_client.addr
236  * @platform_data: stored in i2c_client.dev.platform_data
237  * @archdata: copied into i2c_client.dev.archdata
238  * @of_node: pointer to OpenFirmware device node
239  * @irq: stored in i2c_client.irq
240  *
241  * I2C doesn't actually support hardware probing, although controllers and
242  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
243  * a device at a given address.  Drivers commonly need more information than
244  * that, such as chip type, configuration, associated IRQ, and so on.
245  *
246  * i2c_board_info is used to build tables of information listing I2C devices
247  * that are present.  This information is used to grow the driver model tree.
248  * For mainboards this is done statically using i2c_register_board_info();
249  * bus numbers identify adapters that aren't yet available.  For add-on boards,
250  * i2c_new_device() does this dynamically with the adapter already known.
251  */
252 struct i2c_board_info {
253 	char		type[I2C_NAME_SIZE];
254 	unsigned short	flags;
255 	unsigned short	addr;
256 	void		*platform_data;
257 	struct dev_archdata	*archdata;
258 #ifdef CONFIG_OF
259 	struct device_node *of_node;
260 #endif
261 	int		irq;
262 };
263 
264 /**
265  * I2C_BOARD_INFO - macro used to list an i2c device and its address
266  * @dev_type: identifies the device type
267  * @dev_addr: the device's address on the bus.
268  *
269  * This macro initializes essential fields of a struct i2c_board_info,
270  * declaring what has been provided on a particular board.  Optional
271  * fields (such as associated irq, or device-specific platform_data)
272  * are provided using conventional syntax.
273  */
274 #define I2C_BOARD_INFO(dev_type, dev_addr) \
275 	.type = dev_type, .addr = (dev_addr)
276 
277 
278 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
279 /* Add-on boards should register/unregister their devices; e.g. a board
280  * with integrated I2C, a config eeprom, sensors, and a codec that's
281  * used in conjunction with the primary hardware.
282  */
283 extern struct i2c_client *
284 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
285 
286 /* If you don't know the exact address of an I2C device, use this variant
287  * instead, which can probe for device presence in a list of possible
288  * addresses. The "probe" callback function is optional. If it is provided,
289  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
290  * a default probing method is used.
291  */
292 extern struct i2c_client *
293 i2c_new_probed_device(struct i2c_adapter *adap,
294 		      struct i2c_board_info *info,
295 		      unsigned short const *addr_list,
296 		      int (*probe)(struct i2c_adapter *, unsigned short addr));
297 
298 /* Common custom probe functions */
299 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
300 
301 /* For devices that use several addresses, use i2c_new_dummy() to make
302  * client handles for the extra addresses.
303  */
304 extern struct i2c_client *
305 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
306 
307 extern void i2c_unregister_device(struct i2c_client *);
308 #endif /* I2C */
309 
310 /* Mainboard arch_initcall() code should register all its I2C devices.
311  * This is done at arch_initcall time, before declaring any i2c adapters.
312  * Modules for add-on boards must use other calls.
313  */
314 #ifdef CONFIG_I2C_BOARDINFO
315 extern int
316 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
317 			unsigned n);
318 #else
319 static inline int
320 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
321 			unsigned n)
322 {
323 	return 0;
324 }
325 #endif /* I2C_BOARDINFO */
326 
327 /*
328  * The following structs are for those who like to implement new bus drivers:
329  * i2c_algorithm is the interface to a class of hardware solutions which can
330  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
331  * to name two of the most common.
332  */
333 struct i2c_algorithm {
334 	/* If an adapter algorithm can't do I2C-level access, set master_xfer
335 	   to NULL. If an adapter algorithm can do SMBus access, set
336 	   smbus_xfer. If set to NULL, the SMBus protocol is simulated
337 	   using common I2C messages */
338 	/* master_xfer should return the number of messages successfully
339 	   processed, or a negative value on error */
340 	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
341 			   int num);
342 	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
343 			   unsigned short flags, char read_write,
344 			   u8 command, int size, union i2c_smbus_data *data);
345 
346 	/* To determine what the adapter supports */
347 	u32 (*functionality) (struct i2c_adapter *);
348 };
349 
350 /*
351  * i2c_adapter is the structure used to identify a physical i2c bus along
352  * with the access algorithms necessary to access it.
353  */
354 struct i2c_adapter {
355 	struct module *owner;
356 	unsigned int id __deprecated;
357 	unsigned int class;		  /* classes to allow probing for */
358 	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
359 	void *algo_data;
360 
361 	/* data fields that are valid for all devices	*/
362 	struct rt_mutex bus_lock;
363 
364 	int timeout;			/* in jiffies */
365 	int retries;
366 	struct device dev;		/* the adapter device */
367 
368 	int nr;
369 	char name[48];
370 	struct completion dev_released;
371 
372 	struct mutex userspace_clients_lock;
373 	struct list_head userspace_clients;
374 };
375 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
376 
377 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
378 {
379 	return dev_get_drvdata(&dev->dev);
380 }
381 
382 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
383 {
384 	dev_set_drvdata(&dev->dev, data);
385 }
386 
387 static inline struct i2c_adapter *
388 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
389 {
390 	struct device *parent = adapter->dev.parent;
391 
392 	if (parent != NULL && parent->type == &i2c_adapter_type)
393 		return to_i2c_adapter(parent);
394 	else
395 		return NULL;
396 }
397 
398 /* Adapter locking functions, exported for shared pin cases */
399 void i2c_lock_adapter(struct i2c_adapter *);
400 void i2c_unlock_adapter(struct i2c_adapter *);
401 
402 /*flags for the client struct: */
403 #define I2C_CLIENT_PEC	0x04		/* Use Packet Error Checking */
404 #define I2C_CLIENT_TEN	0x10		/* we have a ten bit chip address */
405 					/* Must equal I2C_M_TEN below */
406 #define I2C_CLIENT_WAKE	0x80		/* for board_info; true iff can wake */
407 
408 /* i2c adapter classes (bitmask) */
409 #define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
410 #define I2C_CLASS_DDC		(1<<3)	/* DDC bus on graphics adapters */
411 #define I2C_CLASS_SPD		(1<<7)	/* SPD EEPROMs and similar */
412 
413 /* Internal numbers to terminate lists */
414 #define I2C_CLIENT_END		0xfffeU
415 
416 /* The numbers to use to set I2C bus address */
417 #define ANY_I2C_BUS		0xffff
418 
419 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
420 #define I2C_ADDRS(addr, addrs...) \
421 	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
422 
423 
424 /* ----- functions exported by i2c.o */
425 
426 /* administration...
427  */
428 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
429 extern int i2c_add_adapter(struct i2c_adapter *);
430 extern int i2c_del_adapter(struct i2c_adapter *);
431 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
432 
433 extern int i2c_register_driver(struct module *, struct i2c_driver *);
434 extern void i2c_del_driver(struct i2c_driver *);
435 
436 static inline int i2c_add_driver(struct i2c_driver *driver)
437 {
438 	return i2c_register_driver(THIS_MODULE, driver);
439 }
440 
441 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
442 extern void i2c_release_client(struct i2c_client *client);
443 
444 /* call the i2c_client->command() of all attached clients with
445  * the given arguments */
446 extern void i2c_clients_command(struct i2c_adapter *adap,
447 				unsigned int cmd, void *arg);
448 
449 extern struct i2c_adapter *i2c_get_adapter(int id);
450 extern void i2c_put_adapter(struct i2c_adapter *adap);
451 
452 
453 /* Return the functionality mask */
454 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
455 {
456 	return adap->algo->functionality(adap);
457 }
458 
459 /* Return 1 if adapter supports everything we need, 0 if not. */
460 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
461 {
462 	return (func & i2c_get_functionality(adap)) == func;
463 }
464 
465 /* Return the adapter number for a specific adapter */
466 static inline int i2c_adapter_id(struct i2c_adapter *adap)
467 {
468 	return adap->nr;
469 }
470 #endif /* I2C */
471 #endif /* __KERNEL__ */
472 
473 /**
474  * struct i2c_msg - an I2C transaction segment beginning with START
475  * @addr: Slave address, either seven or ten bits.  When this is a ten
476  *	bit address, I2C_M_TEN must be set in @flags and the adapter
477  *	must support I2C_FUNC_10BIT_ADDR.
478  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
479  *	provided unless the adapter exported the relevant I2C_FUNC_*
480  *	flags through i2c_check_functionality().
481  * @len: Number of data bytes in @buf being read from or written to the
482  *	I2C slave address.  For read transactions where I2C_M_RECV_LEN
483  *	is set, the caller guarantees that this buffer can hold up to
484  *	32 bytes in addition to the initial length byte sent by the
485  *	slave (plus, if used, the SMBus PEC); and this value will be
486  *	incremented by the number of block data bytes received.
487  * @buf: The buffer into which data is read, or from which it's written.
488  *
489  * An i2c_msg is the low level representation of one segment of an I2C
490  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
491  * to userspace from i2c-dev, and to I2C adapter drivers through the
492  * @i2c_adapter.@master_xfer() method.
493  *
494  * Except when I2C "protocol mangling" is used, all I2C adapters implement
495  * the standard rules for I2C transactions.  Each transaction begins with a
496  * START.  That is followed by the slave address, and a bit encoding read
497  * versus write.  Then follow all the data bytes, possibly including a byte
498  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
499  * bytes have been transferred and ACKed.  If this is the last message in a
500  * group, it is followed by a STOP.  Otherwise it is followed by the next
501  * @i2c_msg transaction segment, beginning with a (repeated) START.
502  *
503  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
504  * passing certain @flags may have changed those standard protocol behaviors.
505  * Those flags are only for use with broken/nonconforming slaves, and with
506  * adapters which are known to support the specific mangling options they
507  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
508  */
509 struct i2c_msg {
510 	__u16 addr;	/* slave address			*/
511 	__u16 flags;
512 #define I2C_M_TEN		0x0010	/* this is a ten bit chip address */
513 #define I2C_M_RD		0x0001	/* read data, from slave to master */
514 #define I2C_M_NOSTART		0x4000	/* if I2C_FUNC_PROTOCOL_MANGLING */
515 #define I2C_M_REV_DIR_ADDR	0x2000	/* if I2C_FUNC_PROTOCOL_MANGLING */
516 #define I2C_M_IGNORE_NAK	0x1000	/* if I2C_FUNC_PROTOCOL_MANGLING */
517 #define I2C_M_NO_RD_ACK		0x0800	/* if I2C_FUNC_PROTOCOL_MANGLING */
518 #define I2C_M_RECV_LEN		0x0400	/* length will be first received byte */
519 	__u16 len;		/* msg length				*/
520 	__u8 *buf;		/* pointer to msg data			*/
521 };
522 
523 /* To determine what functionality is present */
524 
525 #define I2C_FUNC_I2C			0x00000001
526 #define I2C_FUNC_10BIT_ADDR		0x00000002
527 #define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_NOSTART etc. */
528 #define I2C_FUNC_SMBUS_PEC		0x00000008
529 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
530 #define I2C_FUNC_SMBUS_QUICK		0x00010000
531 #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
532 #define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000
533 #define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000
534 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000
535 #define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000
536 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000
537 #define I2C_FUNC_SMBUS_PROC_CALL	0x00800000
538 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000
539 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
540 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
541 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */
542 
543 #define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
544 					 I2C_FUNC_SMBUS_WRITE_BYTE)
545 #define I2C_FUNC_SMBUS_BYTE_DATA	(I2C_FUNC_SMBUS_READ_BYTE_DATA | \
546 					 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
547 #define I2C_FUNC_SMBUS_WORD_DATA	(I2C_FUNC_SMBUS_READ_WORD_DATA | \
548 					 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
549 #define I2C_FUNC_SMBUS_BLOCK_DATA	(I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
550 					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
551 #define I2C_FUNC_SMBUS_I2C_BLOCK	(I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
552 					 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
553 
554 #define I2C_FUNC_SMBUS_EMUL		(I2C_FUNC_SMBUS_QUICK | \
555 					 I2C_FUNC_SMBUS_BYTE | \
556 					 I2C_FUNC_SMBUS_BYTE_DATA | \
557 					 I2C_FUNC_SMBUS_WORD_DATA | \
558 					 I2C_FUNC_SMBUS_PROC_CALL | \
559 					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
560 					 I2C_FUNC_SMBUS_I2C_BLOCK | \
561 					 I2C_FUNC_SMBUS_PEC)
562 
563 /*
564  * Data for SMBus Messages
565  */
566 #define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */
567 union i2c_smbus_data {
568 	__u8 byte;
569 	__u16 word;
570 	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
571 			       /* and one more for user-space compatibility */
572 };
573 
574 /* i2c_smbus_xfer read or write markers */
575 #define I2C_SMBUS_READ	1
576 #define I2C_SMBUS_WRITE	0
577 
578 /* SMBus transaction types (size parameter in the above functions)
579    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
580 #define I2C_SMBUS_QUICK		    0
581 #define I2C_SMBUS_BYTE		    1
582 #define I2C_SMBUS_BYTE_DATA	    2
583 #define I2C_SMBUS_WORD_DATA	    3
584 #define I2C_SMBUS_PROC_CALL	    4
585 #define I2C_SMBUS_BLOCK_DATA	    5
586 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
587 #define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */
588 #define I2C_SMBUS_I2C_BLOCK_DATA    8
589 
590 #endif /* _LINUX_I2C_H */
591