xref: /linux-6.15/include/linux/i2c.h (revision f7be3455)
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/mod_devicetable.h>
33 #include <linux/device.h>	/* for struct device */
34 #include <linux/sched.h>	/* for completion */
35 #include <linux/mutex.h>
36 #include <linux/of.h>		/* for struct device_node */
37 #include <linux/swab.h>		/* for swab16 */
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(const struct i2c_client *client, const char *buf,
61 			   int count);
62 extern int i2c_master_recv(const struct i2c_client *client, char *buf,
63 			   int count);
64 
65 /* Transfer num messages.
66  */
67 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
68 			int num);
69 
70 /* This is the very generalized SMBus access routine. You probably do not
71    want to use this, though; one of the functions below may be much easier,
72    and probably just as fast.
73    Note that we use i2c_adapter here, because you do not need a specific
74    smbus adapter to call this function. */
75 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
76 			  unsigned short flags, char read_write, u8 command,
77 			  int size, union i2c_smbus_data *data);
78 
79 /* Now follow the 'nice' access routines. These also document the calling
80    conventions of i2c_smbus_xfer. */
81 
82 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
83 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
84 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
85 				    u8 command);
86 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
87 				     u8 command, u8 value);
88 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
89 				    u8 command);
90 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
91 				     u8 command, u16 value);
92 
93 static inline s32
94 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
95 {
96 	s32 value = i2c_smbus_read_word_data(client, command);
97 
98 	return (value < 0) ? value : swab16(value);
99 }
100 
101 static inline s32
102 i2c_smbus_write_word_swapped(const struct i2c_client *client,
103 			     u8 command, u16 value)
104 {
105 	return i2c_smbus_write_word_data(client, command, swab16(value));
106 }
107 
108 /* Returns the number of read bytes */
109 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
110 				     u8 command, u8 *values);
111 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
112 				      u8 command, u8 length, const u8 *values);
113 /* Returns the number of read bytes */
114 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
115 					 u8 command, u8 length, u8 *values);
116 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
117 					  u8 command, u8 length,
118 					  const u8 *values);
119 #endif /* I2C */
120 
121 /**
122  * struct i2c_driver - represent an I2C device driver
123  * @class: What kind of i2c device we instantiate (for detect)
124  * @attach_adapter: Callback for bus addition (deprecated)
125  * @detach_adapter: Callback for bus removal (deprecated)
126  * @probe: Callback for device binding
127  * @remove: Callback for device unbinding
128  * @shutdown: Callback for device shutdown
129  * @suspend: Callback for device suspend
130  * @resume: Callback for device resume
131  * @alert: Alert callback, for example for the SMBus alert protocol
132  * @command: Callback for bus-wide signaling (optional)
133  * @driver: Device driver model driver
134  * @id_table: List of I2C devices supported by this driver
135  * @detect: Callback for device detection
136  * @address_list: The I2C addresses to probe (for detect)
137  * @clients: List of detected clients we created (for i2c-core use only)
138  *
139  * The driver.owner field should be set to the module owner of this driver.
140  * The driver.name field should be set to the name of this driver.
141  *
142  * For automatic device detection, both @detect and @address_data must
143  * be defined. @class should also be set, otherwise only devices forced
144  * with module parameters will be created. The detect function must
145  * fill at least the name field of the i2c_board_info structure it is
146  * handed upon successful detection, and possibly also the flags field.
147  *
148  * If @detect is missing, the driver will still work fine for enumerated
149  * devices. Detected devices simply won't be supported. This is expected
150  * for the many I2C/SMBus devices which can't be detected reliably, and
151  * the ones which can always be enumerated in practice.
152  *
153  * The i2c_client structure which is handed to the @detect callback is
154  * not a real i2c_client. It is initialized just enough so that you can
155  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
156  * else with it. In particular, calling dev_dbg and friends on it is
157  * not allowed.
158  */
159 struct i2c_driver {
160 	unsigned int class;
161 
162 	/* Notifies the driver that a new bus has appeared or is about to be
163 	 * removed. You should avoid using this, it will be removed in a
164 	 * near future.
165 	 */
166 	int (*attach_adapter)(struct i2c_adapter *) __deprecated;
167 	int (*detach_adapter)(struct i2c_adapter *) __deprecated;
168 
169 	/* Standard driver model interfaces */
170 	int (*probe)(struct i2c_client *, const struct i2c_device_id *);
171 	int (*remove)(struct i2c_client *);
172 
173 	/* driver model interfaces that don't relate to enumeration  */
174 	void (*shutdown)(struct i2c_client *);
175 	int (*suspend)(struct i2c_client *, pm_message_t mesg);
176 	int (*resume)(struct i2c_client *);
177 
178 	/* Alert callback, for example for the SMBus alert protocol.
179 	 * The format and meaning of the data value depends on the protocol.
180 	 * For the SMBus alert protocol, there is a single bit of data passed
181 	 * as the alert response's low bit ("event flag").
182 	 */
183 	void (*alert)(struct i2c_client *, unsigned int data);
184 
185 	/* a ioctl like command that can be used to perform specific functions
186 	 * with the device.
187 	 */
188 	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
189 
190 	struct device_driver driver;
191 	const struct i2c_device_id *id_table;
192 
193 	/* Device detection callback for automatic device creation */
194 	int (*detect)(struct i2c_client *, struct i2c_board_info *);
195 	const unsigned short *address_list;
196 	struct list_head clients;
197 };
198 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
199 
200 /**
201  * struct i2c_client - represent an I2C slave device
202  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
203  *	I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
204  * @addr: Address used on the I2C bus connected to the parent adapter.
205  * @name: Indicates the type of the device, usually a chip name that's
206  *	generic enough to hide second-sourcing and compatible revisions.
207  * @adapter: manages the bus segment hosting this I2C device
208  * @driver: device's driver, hence pointer to access routines
209  * @dev: Driver model device node for the slave.
210  * @irq: indicates the IRQ generated by this device (if any)
211  * @detected: member of an i2c_driver.clients list or i2c-core's
212  *	userspace_devices list
213  *
214  * An i2c_client identifies a single device (i.e. chip) connected to an
215  * i2c bus. The behaviour exposed to Linux is defined by the driver
216  * managing the device.
217  */
218 struct i2c_client {
219 	unsigned short flags;		/* div., see below		*/
220 	unsigned short addr;		/* chip address - NOTE: 7bit	*/
221 					/* addresses are stored in the	*/
222 					/* _LOWER_ 7 bits		*/
223 	char name[I2C_NAME_SIZE];
224 	struct i2c_adapter *adapter;	/* the adapter we sit on	*/
225 	struct i2c_driver *driver;	/* and our access routines	*/
226 	struct device dev;		/* the device structure		*/
227 	int irq;			/* irq issued by device		*/
228 	struct list_head detected;
229 };
230 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
231 
232 extern struct i2c_client *i2c_verify_client(struct device *dev);
233 
234 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
235 {
236 	struct device * const dev = container_of(kobj, struct device, kobj);
237 	return to_i2c_client(dev);
238 }
239 
240 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
241 {
242 	return dev_get_drvdata(&dev->dev);
243 }
244 
245 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
246 {
247 	dev_set_drvdata(&dev->dev, data);
248 }
249 
250 /**
251  * struct i2c_board_info - template for device creation
252  * @type: chip type, to initialize i2c_client.name
253  * @flags: to initialize i2c_client.flags
254  * @addr: stored in i2c_client.addr
255  * @platform_data: stored in i2c_client.dev.platform_data
256  * @archdata: copied into i2c_client.dev.archdata
257  * @of_node: pointer to OpenFirmware device node
258  * @irq: stored in i2c_client.irq
259  *
260  * I2C doesn't actually support hardware probing, although controllers and
261  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
262  * a device at a given address.  Drivers commonly need more information than
263  * that, such as chip type, configuration, associated IRQ, and so on.
264  *
265  * i2c_board_info is used to build tables of information listing I2C devices
266  * that are present.  This information is used to grow the driver model tree.
267  * For mainboards this is done statically using i2c_register_board_info();
268  * bus numbers identify adapters that aren't yet available.  For add-on boards,
269  * i2c_new_device() does this dynamically with the adapter already known.
270  */
271 struct i2c_board_info {
272 	char		type[I2C_NAME_SIZE];
273 	unsigned short	flags;
274 	unsigned short	addr;
275 	void		*platform_data;
276 	struct dev_archdata	*archdata;
277 	struct device_node *of_node;
278 	int		irq;
279 };
280 
281 /**
282  * I2C_BOARD_INFO - macro used to list an i2c device and its address
283  * @dev_type: identifies the device type
284  * @dev_addr: the device's address on the bus.
285  *
286  * This macro initializes essential fields of a struct i2c_board_info,
287  * declaring what has been provided on a particular board.  Optional
288  * fields (such as associated irq, or device-specific platform_data)
289  * are provided using conventional syntax.
290  */
291 #define I2C_BOARD_INFO(dev_type, dev_addr) \
292 	.type = dev_type, .addr = (dev_addr)
293 
294 
295 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
296 /* Add-on boards should register/unregister their devices; e.g. a board
297  * with integrated I2C, a config eeprom, sensors, and a codec that's
298  * used in conjunction with the primary hardware.
299  */
300 extern struct i2c_client *
301 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
302 
303 /* If you don't know the exact address of an I2C device, use this variant
304  * instead, which can probe for device presence in a list of possible
305  * addresses. The "probe" callback function is optional. If it is provided,
306  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
307  * a default probing method is used.
308  */
309 extern struct i2c_client *
310 i2c_new_probed_device(struct i2c_adapter *adap,
311 		      struct i2c_board_info *info,
312 		      unsigned short const *addr_list,
313 		      int (*probe)(struct i2c_adapter *, unsigned short addr));
314 
315 /* Common custom probe functions */
316 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
317 
318 /* For devices that use several addresses, use i2c_new_dummy() to make
319  * client handles for the extra addresses.
320  */
321 extern struct i2c_client *
322 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
323 
324 extern void i2c_unregister_device(struct i2c_client *);
325 #endif /* I2C */
326 
327 /* Mainboard arch_initcall() code should register all its I2C devices.
328  * This is done at arch_initcall time, before declaring any i2c adapters.
329  * Modules for add-on boards must use other calls.
330  */
331 #ifdef CONFIG_I2C_BOARDINFO
332 extern int
333 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
334 			unsigned n);
335 #else
336 static inline int
337 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
338 			unsigned n)
339 {
340 	return 0;
341 }
342 #endif /* I2C_BOARDINFO */
343 
344 /*
345  * The following structs are for those who like to implement new bus drivers:
346  * i2c_algorithm is the interface to a class of hardware solutions which can
347  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
348  * to name two of the most common.
349  */
350 struct i2c_algorithm {
351 	/* If an adapter algorithm can't do I2C-level access, set master_xfer
352 	   to NULL. If an adapter algorithm can do SMBus access, set
353 	   smbus_xfer. If set to NULL, the SMBus protocol is simulated
354 	   using common I2C messages */
355 	/* master_xfer should return the number of messages successfully
356 	   processed, or a negative value on error */
357 	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
358 			   int num);
359 	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
360 			   unsigned short flags, char read_write,
361 			   u8 command, int size, union i2c_smbus_data *data);
362 
363 	/* To determine what the adapter supports */
364 	u32 (*functionality) (struct i2c_adapter *);
365 };
366 
367 /*
368  * i2c_adapter is the structure used to identify a physical i2c bus along
369  * with the access algorithms necessary to access it.
370  */
371 struct i2c_adapter {
372 	struct module *owner;
373 	unsigned int class;		  /* classes to allow probing for */
374 	const struct i2c_algorithm *algo; /* the algorithm to access the bus */
375 	void *algo_data;
376 
377 	/* data fields that are valid for all devices	*/
378 	struct rt_mutex bus_lock;
379 
380 	int timeout;			/* in jiffies */
381 	int retries;
382 	struct device dev;		/* the adapter device */
383 
384 	int nr;
385 	char name[48];
386 	struct completion dev_released;
387 
388 	struct mutex userspace_clients_lock;
389 	struct list_head userspace_clients;
390 };
391 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
392 
393 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
394 {
395 	return dev_get_drvdata(&dev->dev);
396 }
397 
398 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
399 {
400 	dev_set_drvdata(&dev->dev, data);
401 }
402 
403 static inline struct i2c_adapter *
404 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
405 {
406 	struct device *parent = adapter->dev.parent;
407 
408 	if (parent != NULL && parent->type == &i2c_adapter_type)
409 		return to_i2c_adapter(parent);
410 	else
411 		return NULL;
412 }
413 
414 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
415 
416 /* Adapter locking functions, exported for shared pin cases */
417 void i2c_lock_adapter(struct i2c_adapter *);
418 void i2c_unlock_adapter(struct i2c_adapter *);
419 
420 /*flags for the client struct: */
421 #define I2C_CLIENT_PEC	0x04		/* Use Packet Error Checking */
422 #define I2C_CLIENT_TEN	0x10		/* we have a ten bit chip address */
423 					/* Must equal I2C_M_TEN below */
424 #define I2C_CLIENT_WAKE	0x80		/* for board_info; true iff can wake */
425 
426 /* i2c adapter classes (bitmask) */
427 #define I2C_CLASS_HWMON		(1<<0)	/* lm_sensors, ... */
428 #define I2C_CLASS_DDC		(1<<3)	/* DDC bus on graphics adapters */
429 #define I2C_CLASS_SPD		(1<<7)	/* Memory modules */
430 
431 /* Internal numbers to terminate lists */
432 #define I2C_CLIENT_END		0xfffeU
433 
434 /* The numbers to use to set I2C bus address */
435 #define ANY_I2C_BUS		0xffff
436 
437 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
438 #define I2C_ADDRS(addr, addrs...) \
439 	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
440 
441 
442 /* ----- functions exported by i2c.o */
443 
444 /* administration...
445  */
446 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
447 extern int i2c_add_adapter(struct i2c_adapter *);
448 extern int i2c_del_adapter(struct i2c_adapter *);
449 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
450 
451 extern int i2c_register_driver(struct module *, struct i2c_driver *);
452 extern void i2c_del_driver(struct i2c_driver *);
453 
454 static inline int i2c_add_driver(struct i2c_driver *driver)
455 {
456 	return i2c_register_driver(THIS_MODULE, driver);
457 }
458 
459 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
460 extern void i2c_release_client(struct i2c_client *client);
461 
462 /* call the i2c_client->command() of all attached clients with
463  * the given arguments */
464 extern void i2c_clients_command(struct i2c_adapter *adap,
465 				unsigned int cmd, void *arg);
466 
467 extern struct i2c_adapter *i2c_get_adapter(int nr);
468 extern void i2c_put_adapter(struct i2c_adapter *adap);
469 
470 
471 /* Return the functionality mask */
472 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
473 {
474 	return adap->algo->functionality(adap);
475 }
476 
477 /* Return 1 if adapter supports everything we need, 0 if not. */
478 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
479 {
480 	return (func & i2c_get_functionality(adap)) == func;
481 }
482 
483 /* Return the adapter number for a specific adapter */
484 static inline int i2c_adapter_id(struct i2c_adapter *adap)
485 {
486 	return adap->nr;
487 }
488 #endif /* I2C */
489 #endif /* __KERNEL__ */
490 
491 /**
492  * struct i2c_msg - an I2C transaction segment beginning with START
493  * @addr: Slave address, either seven or ten bits.  When this is a ten
494  *	bit address, I2C_M_TEN must be set in @flags and the adapter
495  *	must support I2C_FUNC_10BIT_ADDR.
496  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
497  *	provided unless the adapter exported the relevant I2C_FUNC_*
498  *	flags through i2c_check_functionality().
499  * @len: Number of data bytes in @buf being read from or written to the
500  *	I2C slave address.  For read transactions where I2C_M_RECV_LEN
501  *	is set, the caller guarantees that this buffer can hold up to
502  *	32 bytes in addition to the initial length byte sent by the
503  *	slave (plus, if used, the SMBus PEC); and this value will be
504  *	incremented by the number of block data bytes received.
505  * @buf: The buffer into which data is read, or from which it's written.
506  *
507  * An i2c_msg is the low level representation of one segment of an I2C
508  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
509  * to userspace from i2c-dev, and to I2C adapter drivers through the
510  * @i2c_adapter.@master_xfer() method.
511  *
512  * Except when I2C "protocol mangling" is used, all I2C adapters implement
513  * the standard rules for I2C transactions.  Each transaction begins with a
514  * START.  That is followed by the slave address, and a bit encoding read
515  * versus write.  Then follow all the data bytes, possibly including a byte
516  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
517  * bytes have been transferred and ACKed.  If this is the last message in a
518  * group, it is followed by a STOP.  Otherwise it is followed by the next
519  * @i2c_msg transaction segment, beginning with a (repeated) START.
520  *
521  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
522  * passing certain @flags may have changed those standard protocol behaviors.
523  * Those flags are only for use with broken/nonconforming slaves, and with
524  * adapters which are known to support the specific mangling options they
525  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
526  */
527 struct i2c_msg {
528 	__u16 addr;	/* slave address			*/
529 	__u16 flags;
530 #define I2C_M_TEN		0x0010	/* this is a ten bit chip address */
531 #define I2C_M_RD		0x0001	/* read data, from slave to master */
532 #define I2C_M_NOSTART		0x4000	/* if I2C_FUNC_PROTOCOL_MANGLING */
533 #define I2C_M_REV_DIR_ADDR	0x2000	/* if I2C_FUNC_PROTOCOL_MANGLING */
534 #define I2C_M_IGNORE_NAK	0x1000	/* if I2C_FUNC_PROTOCOL_MANGLING */
535 #define I2C_M_NO_RD_ACK		0x0800	/* if I2C_FUNC_PROTOCOL_MANGLING */
536 #define I2C_M_RECV_LEN		0x0400	/* length will be first received byte */
537 	__u16 len;		/* msg length				*/
538 	__u8 *buf;		/* pointer to msg data			*/
539 };
540 
541 /* To determine what functionality is present */
542 
543 #define I2C_FUNC_I2C			0x00000001
544 #define I2C_FUNC_10BIT_ADDR		0x00000002
545 #define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_NOSTART etc. */
546 #define I2C_FUNC_SMBUS_PEC		0x00000008
547 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
548 #define I2C_FUNC_SMBUS_QUICK		0x00010000
549 #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
550 #define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000
551 #define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000
552 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000
553 #define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000
554 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000
555 #define I2C_FUNC_SMBUS_PROC_CALL	0x00800000
556 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000
557 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
558 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 /* I2C-like block xfer  */
559 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 /* w/ 1-byte reg. addr. */
560 
561 #define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
562 					 I2C_FUNC_SMBUS_WRITE_BYTE)
563 #define I2C_FUNC_SMBUS_BYTE_DATA	(I2C_FUNC_SMBUS_READ_BYTE_DATA | \
564 					 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
565 #define I2C_FUNC_SMBUS_WORD_DATA	(I2C_FUNC_SMBUS_READ_WORD_DATA | \
566 					 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
567 #define I2C_FUNC_SMBUS_BLOCK_DATA	(I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
568 					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
569 #define I2C_FUNC_SMBUS_I2C_BLOCK	(I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
570 					 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
571 
572 #define I2C_FUNC_SMBUS_EMUL		(I2C_FUNC_SMBUS_QUICK | \
573 					 I2C_FUNC_SMBUS_BYTE | \
574 					 I2C_FUNC_SMBUS_BYTE_DATA | \
575 					 I2C_FUNC_SMBUS_WORD_DATA | \
576 					 I2C_FUNC_SMBUS_PROC_CALL | \
577 					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
578 					 I2C_FUNC_SMBUS_I2C_BLOCK | \
579 					 I2C_FUNC_SMBUS_PEC)
580 
581 /*
582  * Data for SMBus Messages
583  */
584 #define I2C_SMBUS_BLOCK_MAX	32	/* As specified in SMBus standard */
585 union i2c_smbus_data {
586 	__u8 byte;
587 	__u16 word;
588 	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
589 			       /* and one more for user-space compatibility */
590 };
591 
592 /* i2c_smbus_xfer read or write markers */
593 #define I2C_SMBUS_READ	1
594 #define I2C_SMBUS_WRITE	0
595 
596 /* SMBus transaction types (size parameter in the above functions)
597    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
598 #define I2C_SMBUS_QUICK		    0
599 #define I2C_SMBUS_BYTE		    1
600 #define I2C_SMBUS_BYTE_DATA	    2
601 #define I2C_SMBUS_WORD_DATA	    3
602 #define I2C_SMBUS_PROC_CALL	    4
603 #define I2C_SMBUS_BLOCK_DATA	    5
604 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
605 #define I2C_SMBUS_BLOCK_PROC_CALL   7		/* SMBus 2.0 */
606 #define I2C_SMBUS_I2C_BLOCK_DATA    8
607 
608 #endif /* _LINUX_I2C_H */
609