1 /* ------------------------------------------------------------------------- */
3 /* i2c.h - definitions for the i2c-bus interface */
5 /* ------------------------------------------------------------------------- */
6 /* Copyright (C) 1995-2000 Simon G. Vogl
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.
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.
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., 51 Franklin Street, Fifth Floor, Boston,
22 /* ------------------------------------------------------------------------- */
24 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
25 Frodo Looijaard <frodol@dds.nl> */
30 #include <linux/types.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 */
39 extern struct bus_type i2c_bus_type
;
40 extern struct device_type i2c_adapter_type
;
42 /* --- General options ------------------------------------------------ */
50 struct i2c_board_info
;
54 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
56 * The master routines are the ones normally used to transmit data to devices
57 * on a bus (or read from them). Apart from two basic transfer functions to
58 * transmit one message at a time, a more complex version can be used to
59 * transmit an arbitrary number of messages without interruption.
60 * @count must be be less than 64k since msg.len is u16.
62 extern int i2c_master_send(const struct i2c_client
*client
, const char *buf
,
64 extern int i2c_master_recv(const struct i2c_client
*client
, char *buf
,
67 /* Transfer num messages.
69 extern int i2c_transfer(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
72 /* This is the very generalized SMBus access routine. You probably do not
73 want to use this, though; one of the functions below may be much easier,
74 and probably just as fast.
75 Note that we use i2c_adapter here, because you do not need a specific
76 smbus adapter to call this function. */
77 extern s32
i2c_smbus_xfer(struct i2c_adapter
*adapter
, u16 addr
,
78 unsigned short flags
, char read_write
, u8 command
,
79 int size
, union i2c_smbus_data
*data
);
81 /* Now follow the 'nice' access routines. These also document the calling
82 conventions of i2c_smbus_xfer. */
84 extern s32
i2c_smbus_read_byte(const struct i2c_client
*client
);
85 extern s32
i2c_smbus_write_byte(const struct i2c_client
*client
, u8 value
);
86 extern s32
i2c_smbus_read_byte_data(const struct i2c_client
*client
,
88 extern s32
i2c_smbus_write_byte_data(const struct i2c_client
*client
,
89 u8 command
, u8 value
);
90 extern s32
i2c_smbus_read_word_data(const struct i2c_client
*client
,
92 extern s32
i2c_smbus_write_word_data(const struct i2c_client
*client
,
93 u8 command
, u16 value
);
96 i2c_smbus_read_word_swapped(const struct i2c_client
*client
, u8 command
)
98 s32 value
= i2c_smbus_read_word_data(client
, command
);
100 return (value
< 0) ? value
: swab16(value
);
104 i2c_smbus_write_word_swapped(const struct i2c_client
*client
,
105 u8 command
, u16 value
)
107 return i2c_smbus_write_word_data(client
, command
, swab16(value
));
110 /* Returns the number of read bytes */
111 extern s32
i2c_smbus_read_block_data(const struct i2c_client
*client
,
112 u8 command
, u8
*values
);
113 extern s32
i2c_smbus_write_block_data(const struct i2c_client
*client
,
114 u8 command
, u8 length
, const u8
*values
);
115 /* Returns the number of read bytes */
116 extern s32
i2c_smbus_read_i2c_block_data(const struct i2c_client
*client
,
117 u8 command
, u8 length
, u8
*values
);
118 extern s32
i2c_smbus_write_i2c_block_data(const struct i2c_client
*client
,
119 u8 command
, u8 length
,
124 * struct i2c_driver - represent an I2C device driver
125 * @class: What kind of i2c device we instantiate (for detect)
126 * @attach_adapter: Callback for bus addition (deprecated)
127 * @detach_adapter: Callback for bus removal (deprecated)
128 * @probe: Callback for device binding
129 * @remove: Callback for device unbinding
130 * @shutdown: Callback for device shutdown
131 * @suspend: Callback for device suspend
132 * @resume: Callback for device resume
133 * @alert: Alert callback, for example for the SMBus alert protocol
134 * @command: Callback for bus-wide signaling (optional)
135 * @driver: Device driver model driver
136 * @id_table: List of I2C devices supported by this driver
137 * @detect: Callback for device detection
138 * @address_list: The I2C addresses to probe (for detect)
139 * @clients: List of detected clients we created (for i2c-core use only)
141 * The driver.owner field should be set to the module owner of this driver.
142 * The driver.name field should be set to the name of this driver.
144 * For automatic device detection, both @detect and @address_data must
145 * be defined. @class should also be set, otherwise only devices forced
146 * with module parameters will be created. The detect function must
147 * fill at least the name field of the i2c_board_info structure it is
148 * handed upon successful detection, and possibly also the flags field.
150 * If @detect is missing, the driver will still work fine for enumerated
151 * devices. Detected devices simply won't be supported. This is expected
152 * for the many I2C/SMBus devices which can't be detected reliably, and
153 * the ones which can always be enumerated in practice.
155 * The i2c_client structure which is handed to the @detect callback is
156 * not a real i2c_client. It is initialized just enough so that you can
157 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
158 * else with it. In particular, calling dev_dbg and friends on it is
164 /* Notifies the driver that a new bus has appeared or is about to be
165 * removed. You should avoid using this, it will be removed in a
168 int (*attach_adapter
)(struct i2c_adapter
*) __deprecated
;
169 int (*detach_adapter
)(struct i2c_adapter
*) __deprecated
;
171 /* Standard driver model interfaces */
172 int (*probe
)(struct i2c_client
*, const struct i2c_device_id
*);
173 int (*remove
)(struct i2c_client
*);
175 /* driver model interfaces that don't relate to enumeration */
176 void (*shutdown
)(struct i2c_client
*);
177 int (*suspend
)(struct i2c_client
*, pm_message_t mesg
);
178 int (*resume
)(struct i2c_client
*);
180 /* Alert callback, for example for the SMBus alert protocol.
181 * The format and meaning of the data value depends on the protocol.
182 * For the SMBus alert protocol, there is a single bit of data passed
183 * as the alert response's low bit ("event flag").
185 void (*alert
)(struct i2c_client
*, unsigned int data
);
187 /* a ioctl like command that can be used to perform specific functions
190 int (*command
)(struct i2c_client
*client
, unsigned int cmd
, void *arg
);
192 struct device_driver driver
;
193 const struct i2c_device_id
*id_table
;
195 /* Device detection callback for automatic device creation */
196 int (*detect
)(struct i2c_client
*, struct i2c_board_info
*);
197 const unsigned short *address_list
;
198 struct list_head clients
;
200 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
203 * struct i2c_client - represent an I2C slave device
204 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
205 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
206 * @addr: Address used on the I2C bus connected to the parent adapter.
207 * @name: Indicates the type of the device, usually a chip name that's
208 * generic enough to hide second-sourcing and compatible revisions.
209 * @adapter: manages the bus segment hosting this I2C device
210 * @driver: device's driver, hence pointer to access routines
211 * @dev: Driver model device node for the slave.
212 * @irq: indicates the IRQ generated by this device (if any)
213 * @detected: member of an i2c_driver.clients list or i2c-core's
214 * userspace_devices list
216 * An i2c_client identifies a single device (i.e. chip) connected to an
217 * i2c bus. The behaviour exposed to Linux is defined by the driver
218 * managing the device.
221 unsigned short flags
; /* div., see below */
222 unsigned short addr
; /* chip address - NOTE: 7bit */
223 /* addresses are stored in the */
225 char name
[I2C_NAME_SIZE
];
226 struct i2c_adapter
*adapter
; /* the adapter we sit on */
227 struct i2c_driver
*driver
; /* and our access routines */
228 struct device dev
; /* the device structure */
229 int irq
; /* irq issued by device */
230 struct list_head detected
;
232 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
234 extern struct i2c_client
*i2c_verify_client(struct device
*dev
);
235 extern struct i2c_adapter
*i2c_verify_adapter(struct device
*dev
);
237 static inline struct i2c_client
*kobj_to_i2c_client(struct kobject
*kobj
)
239 struct device
* const dev
= container_of(kobj
, struct device
, kobj
);
240 return to_i2c_client(dev
);
243 static inline void *i2c_get_clientdata(const struct i2c_client
*dev
)
245 return dev_get_drvdata(&dev
->dev
);
248 static inline void i2c_set_clientdata(struct i2c_client
*dev
, void *data
)
250 dev_set_drvdata(&dev
->dev
, data
);
254 * struct i2c_board_info - template for device creation
255 * @type: chip type, to initialize i2c_client.name
256 * @flags: to initialize i2c_client.flags
257 * @addr: stored in i2c_client.addr
258 * @platform_data: stored in i2c_client.dev.platform_data
259 * @archdata: copied into i2c_client.dev.archdata
260 * @of_node: pointer to OpenFirmware device node
261 * @irq: stored in i2c_client.irq
263 * I2C doesn't actually support hardware probing, although controllers and
264 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
265 * a device at a given address. Drivers commonly need more information than
266 * that, such as chip type, configuration, associated IRQ, and so on.
268 * i2c_board_info is used to build tables of information listing I2C devices
269 * that are present. This information is used to grow the driver model tree.
270 * For mainboards this is done statically using i2c_register_board_info();
271 * bus numbers identify adapters that aren't yet available. For add-on boards,
272 * i2c_new_device() does this dynamically with the adapter already known.
274 struct i2c_board_info
{
275 char type
[I2C_NAME_SIZE
];
276 unsigned short flags
;
279 struct dev_archdata
*archdata
;
280 struct device_node
*of_node
;
285 * I2C_BOARD_INFO - macro used to list an i2c device and its address
286 * @dev_type: identifies the device type
287 * @dev_addr: the device's address on the bus.
289 * This macro initializes essential fields of a struct i2c_board_info,
290 * declaring what has been provided on a particular board. Optional
291 * fields (such as associated irq, or device-specific platform_data)
292 * are provided using conventional syntax.
294 #define I2C_BOARD_INFO(dev_type, dev_addr) \
295 .type = dev_type, .addr = (dev_addr)
298 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
299 /* Add-on boards should register/unregister their devices; e.g. a board
300 * with integrated I2C, a config eeprom, sensors, and a codec that's
301 * used in conjunction with the primary hardware.
303 extern struct i2c_client
*
304 i2c_new_device(struct i2c_adapter
*adap
, struct i2c_board_info
const *info
);
306 /* If you don't know the exact address of an I2C device, use this variant
307 * instead, which can probe for device presence in a list of possible
308 * addresses. The "probe" callback function is optional. If it is provided,
309 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
310 * a default probing method is used.
312 extern struct i2c_client
*
313 i2c_new_probed_device(struct i2c_adapter
*adap
,
314 struct i2c_board_info
*info
,
315 unsigned short const *addr_list
,
316 int (*probe
)(struct i2c_adapter
*, unsigned short addr
));
318 /* Common custom probe functions */
319 extern int i2c_probe_func_quick_read(struct i2c_adapter
*, unsigned short addr
);
321 /* For devices that use several addresses, use i2c_new_dummy() to make
322 * client handles for the extra addresses.
324 extern struct i2c_client
*
325 i2c_new_dummy(struct i2c_adapter
*adap
, u16 address
);
327 extern void i2c_unregister_device(struct i2c_client
*);
330 /* Mainboard arch_initcall() code should register all its I2C devices.
331 * This is done at arch_initcall time, before declaring any i2c adapters.
332 * Modules for add-on boards must use other calls.
334 #ifdef CONFIG_I2C_BOARDINFO
336 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
340 i2c_register_board_info(int busnum
, struct i2c_board_info
const *info
,
345 #endif /* I2C_BOARDINFO */
348 * The following structs are for those who like to implement new bus drivers:
349 * i2c_algorithm is the interface to a class of hardware solutions which can
350 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
351 * to name two of the most common.
353 struct i2c_algorithm
{
354 /* If an adapter algorithm can't do I2C-level access, set master_xfer
355 to NULL. If an adapter algorithm can do SMBus access, set
356 smbus_xfer. If set to NULL, the SMBus protocol is simulated
357 using common I2C messages */
358 /* master_xfer should return the number of messages successfully
359 processed, or a negative value on error */
360 int (*master_xfer
)(struct i2c_adapter
*adap
, struct i2c_msg
*msgs
,
362 int (*smbus_xfer
) (struct i2c_adapter
*adap
, u16 addr
,
363 unsigned short flags
, char read_write
,
364 u8 command
, int size
, union i2c_smbus_data
*data
);
366 /* To determine what the adapter supports */
367 u32 (*functionality
) (struct i2c_adapter
*);
371 * i2c_adapter is the structure used to identify a physical i2c bus along
372 * with the access algorithms necessary to access it.
375 struct module
*owner
;
376 unsigned int class; /* classes to allow probing for */
377 const struct i2c_algorithm
*algo
; /* the algorithm to access the bus */
380 /* data fields that are valid for all devices */
381 struct rt_mutex bus_lock
;
383 int timeout
; /* in jiffies */
385 struct device dev
; /* the adapter device */
389 struct completion dev_released
;
391 struct mutex userspace_clients_lock
;
392 struct list_head userspace_clients
;
394 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
396 static inline void *i2c_get_adapdata(const struct i2c_adapter
*dev
)
398 return dev_get_drvdata(&dev
->dev
);
401 static inline void i2c_set_adapdata(struct i2c_adapter
*dev
, void *data
)
403 dev_set_drvdata(&dev
->dev
, data
);
406 static inline struct i2c_adapter
*
407 i2c_parent_is_i2c_adapter(const struct i2c_adapter
*adapter
)
409 struct device
*parent
= adapter
->dev
.parent
;
411 if (parent
!= NULL
&& parent
->type
== &i2c_adapter_type
)
412 return to_i2c_adapter(parent
);
417 int i2c_for_each_dev(void *data
, int (*fn
)(struct device
*, void *));
419 /* Adapter locking functions, exported for shared pin cases */
420 void i2c_lock_adapter(struct i2c_adapter
*);
421 void i2c_unlock_adapter(struct i2c_adapter
*);
423 /*flags for the client struct: */
424 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
425 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
426 /* Must equal I2C_M_TEN below */
427 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
429 /* i2c adapter classes (bitmask) */
430 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
431 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
432 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
434 /* Internal numbers to terminate lists */
435 #define I2C_CLIENT_END 0xfffeU
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 })
442 /* ----- functions exported by i2c.o */
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
*);
451 extern int i2c_register_driver(struct module
*, struct i2c_driver
*);
452 extern void i2c_del_driver(struct i2c_driver
*);
454 /* use a define to avoid include chaining to get THIS_MODULE */
455 #define i2c_add_driver(driver) \
456 i2c_register_driver(THIS_MODULE, driver)
458 extern struct i2c_client
*i2c_use_client(struct i2c_client
*client
);
459 extern void i2c_release_client(struct i2c_client
*client
);
461 /* call the i2c_client->command() of all attached clients with
462 * the given arguments */
463 extern void i2c_clients_command(struct i2c_adapter
*adap
,
464 unsigned int cmd
, void *arg
);
466 extern struct i2c_adapter
*i2c_get_adapter(int nr
);
467 extern void i2c_put_adapter(struct i2c_adapter
*adap
);
470 /* Return the functionality mask */
471 static inline u32
i2c_get_functionality(struct i2c_adapter
*adap
)
473 return adap
->algo
->functionality(adap
);
476 /* Return 1 if adapter supports everything we need, 0 if not. */
477 static inline int i2c_check_functionality(struct i2c_adapter
*adap
, u32 func
)
479 return (func
& i2c_get_functionality(adap
)) == func
;
482 /* Return the adapter number for a specific adapter */
483 static inline int i2c_adapter_id(struct i2c_adapter
*adap
)
489 * module_i2c_driver() - Helper macro for registering a I2C driver
490 * @__i2c_driver: i2c_driver struct
492 * Helper macro for I2C drivers which do not do anything special in module
493 * init/exit. This eliminates a lot of boilerplate. Each module may only
494 * use this macro once, and calling it replaces module_init() and module_exit()
496 #define module_i2c_driver(__i2c_driver) \
497 module_driver(__i2c_driver, i2c_add_driver, \
501 #endif /* __KERNEL__ */
504 * struct i2c_msg - an I2C transaction segment beginning with START
505 * @addr: Slave address, either seven or ten bits. When this is a ten
506 * bit address, I2C_M_TEN must be set in @flags and the adapter
507 * must support I2C_FUNC_10BIT_ADDR.
508 * @flags: I2C_M_RD is handled by all adapters. No other flags may be
509 * provided unless the adapter exported the relevant I2C_FUNC_*
510 * flags through i2c_check_functionality().
511 * @len: Number of data bytes in @buf being read from or written to the
512 * I2C slave address. For read transactions where I2C_M_RECV_LEN
513 * is set, the caller guarantees that this buffer can hold up to
514 * 32 bytes in addition to the initial length byte sent by the
515 * slave (plus, if used, the SMBus PEC); and this value will be
516 * incremented by the number of block data bytes received.
517 * @buf: The buffer into which data is read, or from which it's written.
519 * An i2c_msg is the low level representation of one segment of an I2C
520 * transaction. It is visible to drivers in the @i2c_transfer() procedure,
521 * to userspace from i2c-dev, and to I2C adapter drivers through the
522 * @i2c_adapter.@master_xfer() method.
524 * Except when I2C "protocol mangling" is used, all I2C adapters implement
525 * the standard rules for I2C transactions. Each transaction begins with a
526 * START. That is followed by the slave address, and a bit encoding read
527 * versus write. Then follow all the data bytes, possibly including a byte
528 * with SMBus PEC. The transfer terminates with a NAK, or when all those
529 * bytes have been transferred and ACKed. If this is the last message in a
530 * group, it is followed by a STOP. Otherwise it is followed by the next
531 * @i2c_msg transaction segment, beginning with a (repeated) START.
533 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
534 * passing certain @flags may have changed those standard protocol behaviors.
535 * Those flags are only for use with broken/nonconforming slaves, and with
536 * adapters which are known to support the specific mangling options they
537 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
540 __u16 addr
; /* slave address */
542 #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
543 #define I2C_M_RD 0x0001 /* read data, from slave to master */
544 #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_NOSTART */
545 #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
546 #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
547 #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
548 #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
549 __u16 len
; /* msg length */
550 __u8
*buf
; /* pointer to msg data */
553 /* To determine what functionality is present */
555 #define I2C_FUNC_I2C 0x00000001
556 #define I2C_FUNC_10BIT_ADDR 0x00000002
557 #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_IGNORE_NAK etc. */
558 #define I2C_FUNC_SMBUS_PEC 0x00000008
559 #define I2C_FUNC_NOSTART 0x00000010 /* I2C_M_NOSTART */
560 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
561 #define I2C_FUNC_SMBUS_QUICK 0x00010000
562 #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
563 #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
564 #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
565 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
566 #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
567 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
568 #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
569 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
570 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
571 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */
572 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */
574 #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
575 I2C_FUNC_SMBUS_WRITE_BYTE)
576 #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
577 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
578 #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
579 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
580 #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
581 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
582 #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
583 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
585 #define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
586 I2C_FUNC_SMBUS_BYTE | \
587 I2C_FUNC_SMBUS_BYTE_DATA | \
588 I2C_FUNC_SMBUS_WORD_DATA | \
589 I2C_FUNC_SMBUS_PROC_CALL | \
590 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
591 I2C_FUNC_SMBUS_I2C_BLOCK | \
595 * Data for SMBus Messages
597 #define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
598 union i2c_smbus_data
{
601 __u8 block
[I2C_SMBUS_BLOCK_MAX
+ 2]; /* block[0] is used for length */
602 /* and one more for user-space compatibility */
605 /* i2c_smbus_xfer read or write markers */
606 #define I2C_SMBUS_READ 1
607 #define I2C_SMBUS_WRITE 0
609 /* SMBus transaction types (size parameter in the above functions)
610 Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
611 #define I2C_SMBUS_QUICK 0
612 #define I2C_SMBUS_BYTE 1
613 #define I2C_SMBUS_BYTE_DATA 2
614 #define I2C_SMBUS_WORD_DATA 3
615 #define I2C_SMBUS_PROC_CALL 4
616 #define I2C_SMBUS_BLOCK_DATA 5
617 #define I2C_SMBUS_I2C_BLOCK_BROKEN 6
618 #define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
619 #define I2C_SMBUS_I2C_BLOCK_DATA 8
621 #endif /* _LINUX_I2C_H */