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., 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* ------------------------------------------------------------------------- */
23 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
24 Frodo Looijaard <frodol@dds.nl> */
29 #include <linux/types.h>
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 */
38 extern struct bus_type i2c_bus_type;
39 extern struct device_type i2c_adapter_type;
41 /* --- General options ------------------------------------------------ */
49 struct i2c_board_info;
51 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
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.
59 extern int i2c_master_send(const struct i2c_client *client, const char *buf,
61 extern int i2c_master_recv(const struct i2c_client *client, char *buf,
65 /* If everything went ok, return 'count' transmitted, else error code. */
66 extern int i2c_master_normal_send(const struct i2c_client *client, const char *buf, int count, int scl_rate);
67 extern int i2c_master_normal_recv(const struct i2c_client *client, char *buf, int count, int scl_rate);
68 extern int i2c_master_reg8_send(const struct i2c_client *client, const char reg, const char *buf, int count, int scl_rate);
69 extern int i2c_master_reg8_recv(const struct i2c_client *client, const char reg, char *buf, int count, int scl_rate);
70 extern int i2c_master_reg16_send(const struct i2c_client *client, const short regs, const short *buf, int count, int scl_rate);
71 extern int i2c_master_reg16_recv(const struct i2c_client *client, const short regs, short *buf, int count, int scl_rate);
72 extern int i2c_suspended(struct i2c_adapter *adap);
75 /* Transfer num messages.
77 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
80 /* This is the very generalized SMBus access routine. You probably do not
81 want to use this, though; one of the functions below may be much easier,
82 and probably just as fast.
83 Note that we use i2c_adapter here, because you do not need a specific
84 smbus adapter to call this function. */
85 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
86 unsigned short flags, char read_write, u8 command,
87 int size, union i2c_smbus_data *data);
89 /* Now follow the 'nice' access routines. These also document the calling
90 conventions of i2c_smbus_xfer. */
92 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
93 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
94 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
96 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
97 u8 command, u8 value);
98 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
100 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
101 u8 command, u16 value);
102 /* Returns the number of read bytes */
103 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
104 u8 command, u8 *values);
105 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
106 u8 command, u8 length, const u8 *values);
107 /* Returns the number of read bytes */
108 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
109 u8 command, u8 length, u8 *values);
110 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
111 u8 command, u8 length,
116 * struct i2c_driver - represent an I2C device driver
117 * @class: What kind of i2c device we instantiate (for detect)
118 * @attach_adapter: Callback for bus addition (deprecated)
119 * @detach_adapter: Callback for bus removal (deprecated)
120 * @probe: Callback for device binding
121 * @remove: Callback for device unbinding
122 * @shutdown: Callback for device shutdown
123 * @suspend: Callback for device suspend
124 * @resume: Callback for device resume
125 * @alert: Alert callback, for example for the SMBus alert protocol
126 * @command: Callback for bus-wide signaling (optional)
127 * @driver: Device driver model driver
128 * @id_table: List of I2C devices supported by this driver
129 * @detect: Callback for device detection
130 * @address_list: The I2C addresses to probe (for detect)
131 * @clients: List of detected clients we created (for i2c-core use only)
133 * The driver.owner field should be set to the module owner of this driver.
134 * The driver.name field should be set to the name of this driver.
136 * For automatic device detection, both @detect and @address_data must
137 * be defined. @class should also be set, otherwise only devices forced
138 * with module parameters will be created. The detect function must
139 * fill at least the name field of the i2c_board_info structure it is
140 * handed upon successful detection, and possibly also the flags field.
142 * If @detect is missing, the driver will still work fine for enumerated
143 * devices. Detected devices simply won't be supported. This is expected
144 * for the many I2C/SMBus devices which can't be detected reliably, and
145 * the ones which can always be enumerated in practice.
147 * The i2c_client structure which is handed to the @detect callback is
148 * not a real i2c_client. It is initialized just enough so that you can
149 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
150 * else with it. In particular, calling dev_dbg and friends on it is
156 /* Notifies the driver that a new bus has appeared or is about to be
157 * removed. You should avoid using this, it will be removed in a
160 int (*attach_adapter)(struct i2c_adapter *) __deprecated;
161 int (*detach_adapter)(struct i2c_adapter *) __deprecated;
163 /* Standard driver model interfaces */
164 int (*probe)(struct i2c_client *, const struct i2c_device_id *);
165 int (*remove)(struct i2c_client *);
167 /* driver model interfaces that don't relate to enumeration */
168 void (*shutdown)(struct i2c_client *);
169 int (*suspend)(struct i2c_client *, pm_message_t mesg);
170 int (*resume)(struct i2c_client *);
172 /* Alert callback, for example for the SMBus alert protocol.
173 * The format and meaning of the data value depends on the protocol.
174 * For the SMBus alert protocol, there is a single bit of data passed
175 * as the alert response's low bit ("event flag").
177 void (*alert)(struct i2c_client *, unsigned int data);
179 /* a ioctl like command that can be used to perform specific functions
182 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
184 struct device_driver driver;
185 const struct i2c_device_id *id_table;
187 /* Device detection callback for automatic device creation */
188 int (*detect)(struct i2c_client *, struct i2c_board_info *);
189 const unsigned short *address_list;
190 struct list_head clients;
192 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
195 * struct i2c_client - represent an I2C slave device
196 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
197 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
198 * @addr: Address used on the I2C bus connected to the parent adapter.
199 * @name: Indicates the type of the device, usually a chip name that's
200 * generic enough to hide second-sourcing and compatible revisions.
201 * @adapter: manages the bus segment hosting this I2C device
202 * @driver: device's driver, hence pointer to access routines
203 * @dev: Driver model device node for the slave.
204 * @irq: indicates the IRQ generated by this device (if any)
205 * @detected: member of an i2c_driver.clients list or i2c-core's
206 * userspace_devices list
208 * An i2c_client identifies a single device (i.e. chip) connected to an
209 * i2c bus. The behaviour exposed to Linux is defined by the driver
210 * managing the device.
213 unsigned short flags; /* div., see below */
214 unsigned short addr; /* chip address - NOTE: 7bit */
215 /* addresses are stored in the */
217 char name[I2C_NAME_SIZE];
218 struct i2c_adapter *adapter; /* the adapter we sit on */
219 struct i2c_driver *driver; /* and our access routines */
220 struct device dev; /* the device structure */
221 int irq; /* irq issued by device */
223 struct list_head detected;
225 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
227 extern struct i2c_client *i2c_verify_client(struct device *dev);
229 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
231 struct device * const dev = container_of(kobj, struct device, kobj);
232 return to_i2c_client(dev);
235 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
237 return dev_get_drvdata(&dev->dev);
240 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
242 dev_set_drvdata(&dev->dev, data);
246 * struct i2c_board_info - template for device creation
247 * @type: chip type, to initialize i2c_client.name
248 * @flags: to initialize i2c_client.flags
249 * @addr: stored in i2c_client.addr
250 * @platform_data: stored in i2c_client.dev.platform_data
251 * @archdata: copied into i2c_client.dev.archdata
252 * @of_node: pointer to OpenFirmware device node
253 * @irq: stored in i2c_client.irq
255 * I2C doesn't actually support hardware probing, although controllers and
256 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
257 * a device at a given address. Drivers commonly need more information than
258 * that, such as chip type, configuration, associated IRQ, and so on.
260 * i2c_board_info is used to build tables of information listing I2C devices
261 * that are present. This information is used to grow the driver model tree.
262 * For mainboards this is done statically using i2c_register_board_info();
263 * bus numbers identify adapters that aren't yet available. For add-on boards,
264 * i2c_new_device() does this dynamically with the adapter already known.
266 struct i2c_board_info {
267 char type[I2C_NAME_SIZE];
268 unsigned short flags;
271 struct dev_archdata *archdata;
272 struct device_node *of_node;
274 int udelay; //add by kfx
278 * I2C_BOARD_INFO - macro used to list an i2c device and its address
279 * @dev_type: identifies the device type
280 * @dev_addr: the device's address on the bus.
282 * This macro initializes essential fields of a struct i2c_board_info,
283 * declaring what has been provided on a particular board. Optional
284 * fields (such as associated irq, or device-specific platform_data)
285 * are provided using conventional syntax.
287 #define I2C_BOARD_INFO(dev_type, dev_addr) \
288 .type = dev_type, .addr = (dev_addr)
291 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
292 /* Add-on boards should register/unregister their devices; e.g. a board
293 * with integrated I2C, a config eeprom, sensors, and a codec that's
294 * used in conjunction with the primary hardware.
296 extern struct i2c_client *
297 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
299 /* If you don't know the exact address of an I2C device, use this variant
300 * instead, which can probe for device presence in a list of possible
301 * addresses. The "probe" callback function is optional. If it is provided,
302 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
303 * a default probing method is used.
305 extern struct i2c_client *
306 i2c_new_probed_device(struct i2c_adapter *adap,
307 struct i2c_board_info *info,
308 unsigned short const *addr_list,
309 int (*probe)(struct i2c_adapter *, unsigned short addr));
311 /* Common custom probe functions */
312 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
314 /* For devices that use several addresses, use i2c_new_dummy() to make
315 * client handles for the extra addresses.
317 extern struct i2c_client *
318 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
320 extern void i2c_unregister_device(struct i2c_client *);
323 /* Mainboard arch_initcall() code should register all its I2C devices.
324 * This is done at arch_initcall time, before declaring any i2c adapters.
325 * Modules for add-on boards must use other calls.
327 #ifdef CONFIG_I2C_BOARDINFO
329 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
333 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
338 #endif /* I2C_BOARDINFO */
341 * The following structs are for those who like to implement new bus drivers:
342 * i2c_algorithm is the interface to a class of hardware solutions which can
343 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
344 * to name two of the most common.
346 struct i2c_algorithm {
347 /* If an adapter algorithm can't do I2C-level access, set master_xfer
348 to NULL. If an adapter algorithm can do SMBus access, set
349 smbus_xfer. If set to NULL, the SMBus protocol is simulated
350 using common I2C messages */
351 /* master_xfer should return the number of messages successfully
352 processed, or a negative value on error */
353 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
355 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
356 unsigned short flags, char read_write,
357 u8 command, int size, union i2c_smbus_data *data);
359 /* To determine what the adapter supports */
360 u32 (*functionality) (struct i2c_adapter *);
364 * i2c_adapter is the structure used to identify a physical i2c bus along
365 * with the access algorithms necessary to access it.
368 struct module *owner;
369 unsigned int class; /* classes to allow probing for */
370 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
373 /* data fields that are valid for all devices */
374 struct rt_mutex bus_lock;
376 int timeout; /* in jiffies */
378 struct device dev; /* the adapter device */
382 struct completion dev_released;
384 struct mutex userspace_clients_lock;
385 struct list_head userspace_clients;
387 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
389 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
391 return dev_get_drvdata(&dev->dev);
394 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
396 dev_set_drvdata(&dev->dev, data);
399 static inline struct i2c_adapter *
400 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
402 struct device *parent = adapter->dev.parent;
404 if (parent != NULL && parent->type == &i2c_adapter_type)
405 return to_i2c_adapter(parent);
410 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
412 /* Adapter locking functions, exported for shared pin cases */
413 void i2c_lock_adapter(struct i2c_adapter *);
414 void i2c_unlock_adapter(struct i2c_adapter *);
416 /*flags for the client struct: */
417 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
418 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
419 /* Must equal I2C_M_TEN below */
420 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
422 /* i2c adapter classes (bitmask) */
423 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */
424 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */
425 #define I2C_CLASS_SPD (1<<7) /* Memory modules */
427 /* Internal numbers to terminate lists */
428 #define I2C_CLIENT_END 0xfffeU
430 /* The numbers to use to set I2C bus address */
431 #define ANY_I2C_BUS 0xffff
433 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
434 #define I2C_ADDRS(addr, addrs...) \
435 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
438 /* ----- functions exported by i2c.o */
442 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
443 extern int i2c_add_adapter(struct i2c_adapter *);
444 extern int i2c_del_adapter(struct i2c_adapter *);
445 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
447 extern int i2c_register_driver(struct module *, struct i2c_driver *);
448 extern void i2c_del_driver(struct i2c_driver *);
450 static inline int i2c_add_driver(struct i2c_driver *driver)
452 return i2c_register_driver(THIS_MODULE, driver);
455 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
456 extern void i2c_release_client(struct i2c_client *client);
458 /* call the i2c_client->command() of all attached clients with
459 * the given arguments */
460 extern void i2c_clients_command(struct i2c_adapter *adap,
461 unsigned int cmd, void *arg);
463 extern struct i2c_adapter *i2c_get_adapter(int nr);
464 extern void i2c_put_adapter(struct i2c_adapter *adap);
467 /* Return the functionality mask */
468 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
470 return adap->algo->functionality(adap);
473 /* Return 1 if adapter supports everything we need, 0 if not. */
474 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
476 return (func & i2c_get_functionality(adap)) == func;
479 /* Return the adapter number for a specific adapter */
480 static inline int i2c_adapter_id(struct i2c_adapter *adap)
485 #endif /* __KERNEL__ */
488 * struct i2c_msg - an I2C transaction segment beginning with START
489 * @addr: Slave address, either seven or ten bits. When this is a ten
490 * bit address, I2C_M_TEN must be set in @flags and the adapter
491 * must support I2C_FUNC_10BIT_ADDR.
492 * @flags: I2C_M_RD is handled by all adapters. No other flags may be
493 * provided unless the adapter exported the relevant I2C_FUNC_*
494 * flags through i2c_check_functionality().
495 * @len: Number of data bytes in @buf being read from or written to the
496 * I2C slave address. For read transactions where I2C_M_RECV_LEN
497 * is set, the caller guarantees that this buffer can hold up to
498 * 32 bytes in addition to the initial length byte sent by the
499 * slave (plus, if used, the SMBus PEC); and this value will be
500 * incremented by the number of block data bytes received.
501 * @buf: The buffer into which data is read, or from which it's written.
503 * An i2c_msg is the low level representation of one segment of an I2C
504 * transaction. It is visible to drivers in the @i2c_transfer() procedure,
505 * to userspace from i2c-dev, and to I2C adapter drivers through the
506 * @i2c_adapter.@master_xfer() method.
508 * Except when I2C "protocol mangling" is used, all I2C adapters implement
509 * the standard rules for I2C transactions. Each transaction begins with a
510 * START. That is followed by the slave address, and a bit encoding read
511 * versus write. Then follow all the data bytes, possibly including a byte
512 * with SMBus PEC. The transfer terminates with a NAK, or when all those
513 * bytes have been transferred and ACKed. If this is the last message in a
514 * group, it is followed by a STOP. Otherwise it is followed by the next
515 * @i2c_msg transaction segment, beginning with a (repeated) START.
517 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
518 * passing certain @flags may have changed those standard protocol behaviors.
519 * Those flags are only for use with broken/nonconforming slaves, and with
520 * adapters which are known to support the specific mangling options they
521 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
524 __u16 addr; /* slave address */
526 #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */
527 #define I2C_M_RD 0x0001 /* read data, from slave to master */
528 #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */
529 #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */
530 #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */
531 #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */
532 #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */
533 #define I2C_M_NEED_DELAY 0x0020 // add by kfx
534 #define I2C_M_REG8_DIRECT 0x0040 // add by kfx
535 __u16 len; /* msg length */
536 __u8 *buf; /* pointer to msg data */
537 __u32 scl_rate; // add by kfx
538 int udelay; //add by kfx
542 /* To determine what functionality is present */
544 #define I2C_FUNC_I2C 0x00000001
545 #define I2C_FUNC_10BIT_ADDR 0x00000002
546 #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */
547 #define I2C_FUNC_SMBUS_PEC 0x00000008
548 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */
549 #define I2C_FUNC_SMBUS_QUICK 0x00010000
550 #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
551 #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
552 #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
553 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
554 #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
555 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
556 #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
557 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
558 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
559 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */
560 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */
562 #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
563 I2C_FUNC_SMBUS_WRITE_BYTE)
564 #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
565 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
566 #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
567 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
568 #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
569 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
570 #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
571 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
573 #define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \
574 I2C_FUNC_SMBUS_BYTE | \
575 I2C_FUNC_SMBUS_BYTE_DATA | \
576 I2C_FUNC_SMBUS_WORD_DATA | \
577 I2C_FUNC_SMBUS_PROC_CALL | \
578 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
579 I2C_FUNC_SMBUS_I2C_BLOCK | \
583 * Data for SMBus Messages
585 #define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */
586 union i2c_smbus_data {
589 __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
590 /* and one more for user-space compatibility */
593 /* i2c_smbus_xfer read or write markers */
594 #define I2C_SMBUS_READ 1
595 #define I2C_SMBUS_WRITE 0
597 /* SMBus transaction types (size parameter in the above functions)
598 Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
599 #define I2C_SMBUS_QUICK 0
600 #define I2C_SMBUS_BYTE 1
601 #define I2C_SMBUS_BYTE_DATA 2
602 #define I2C_SMBUS_WORD_DATA 3
603 #define I2C_SMBUS_PROC_CALL 4
604 #define I2C_SMBUS_BLOCK_DATA 5
605 #define I2C_SMBUS_I2C_BLOCK_BROKEN 6
606 #define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */
607 #define I2C_SMBUS_I2C_BLOCK_DATA 8
609 #endif /* _LINUX_I2C_H */