include/linux/i2c.h

   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., 51 Franklin Street, Fifth Floor, Boston,
  21     MA 02110-1301 USA.                                                       */
  22 /* ------------------------------------------------------------------------- */
  23
  24 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
  25    Frodo Looijaard <frodol@dds.nl> */
  26
  27 #ifndef _LINUX_I2C_H
  28 #define _LINUX_I2C_H
  29
  30 #include <linux/types.h>
  31 #ifdef __KERNEL__
  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 struct module;
  53
  54 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
  55 /*
  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.
  61  */
  62 extern int i2c_master_send(const struct i2c_client *client, const char *buf,
  63                            int count);
  64 extern int i2c_master_recv(const struct i2c_client *client, char *buf,
  65                            int count);
  66
  67 /* Transfer num messages.
  68  */
  69 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  70                         int num);
  71 /* Unlocked flavor */
  72 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  73                           int num);
  74
  75 /* This is the very generalized SMBus access routine. You probably do not
  76    want to use this, though; one of the functions below may be much easier,
  77    and probably just as fast.
  78    Note that we use i2c_adapter here, because you do not need a specific
  79    smbus adapter to call this function. */
  80 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
  81                           unsigned short flags, char read_write, u8 command,
  82                           int size, union i2c_smbus_data *data);
  83
  84 /* Now follow the 'nice' access routines. These also document the calling
  85    conventions of i2c_smbus_xfer. */
  86
  87 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
  88 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
  89 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
  90                                     u8 command);
  91 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
  92                                      u8 command, u8 value);
  93 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
  94                                     u8 command);
  95 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
  96                                      u8 command, u16 value);
  97
  98 static inline s32
  99 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
 100 {
 101         s32 value = i2c_smbus_read_word_data(client, command);
 102
 103         return (value < 0) ? value : swab16(value);
 104 }
 105
 106 static inline s32
 107 i2c_smbus_write_word_swapped(const struct i2c_client *client,
 108                              u8 command, u16 value)
 109 {
 110         return i2c_smbus_write_word_data(client, command, swab16(value));
 111 }
 112
 113 /* Returns the number of read bytes */
 114 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
 115                                      u8 command, u8 *values);
 116 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
 117                                       u8 command, u8 length, const u8 *values);
 118 /* Returns the number of read bytes */
 119 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
 120                                          u8 command, u8 length, u8 *values);
 121 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 122                                           u8 command, u8 length,
 123                                           const u8 *values);
 124 #endif /* I2C */
 125
 126 /**
 127  * struct i2c_driver - represent an I2C device driver
 128  * @class: What kind of i2c device we instantiate (for detect)
 129  * @attach_adapter: Callback for bus addition (deprecated)
 130  * @detach_adapter: Callback for bus removal (deprecated)
 131  * @probe: Callback for device binding
 132  * @remove: Callback for device unbinding
 133  * @shutdown: Callback for device shutdown
 134  * @suspend: Callback for device suspend
 135  * @resume: Callback for device resume
 136  * @alert: Alert callback, for example for the SMBus alert protocol
 137  * @command: Callback for bus-wide signaling (optional)
 138  * @driver: Device driver model driver
 139  * @id_table: List of I2C devices supported by this driver
 140  * @detect: Callback for device detection
 141  * @address_list: The I2C addresses to probe (for detect)
 142  * @clients: List of detected clients we created (for i2c-core use only)
 143  *
 144  * The driver.owner field should be set to the module owner of this driver.
 145  * The driver.name field should be set to the name of this driver.
 146  *
 147  * For automatic device detection, both @detect and @address_data must
 148  * be defined. @class should also be set, otherwise only devices forced
 149  * with module parameters will be created. The detect function must
 150  * fill at least the name field of the i2c_board_info structure it is
 151  * handed upon successful detection, and possibly also the flags field.
 152  *
 153  * If @detect is missing, the driver will still work fine for enumerated
 154  * devices. Detected devices simply won't be supported. This is expected
 155  * for the many I2C/SMBus devices which can't be detected reliably, and
 156  * the ones which can always be enumerated in practice.
 157  *
 158  * The i2c_client structure which is handed to the @detect callback is
 159  * not a real i2c_client. It is initialized just enough so that you can
 160  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
 161  * else with it. In particular, calling dev_dbg and friends on it is
 162  * not allowed.
 163  */
 164 struct i2c_driver {
 165         unsigned int class;
 166
 167         /* Notifies the driver that a new bus has appeared or is about to be
 168          * removed. You should avoid using this, it will be removed in a
 169          * near future.
 170          */
 171         int (*attach_adapter)(struct i2c_adapter *) __deprecated;
 172         int (*detach_adapter)(struct i2c_adapter *) __deprecated;
 173
 174         /* Standard driver model interfaces */
 175         int (*probe)(struct i2c_client *, const struct i2c_device_id *);
 176         int (*remove)(struct i2c_client *);
 177
 178         /* driver model interfaces that don't relate to enumeration  */
 179         void (*shutdown)(struct i2c_client *);
 180         int (*suspend)(struct i2c_client *, pm_message_t mesg);
 181         int (*resume)(struct i2c_client *);
 182
 183         /* Alert callback, for example for the SMBus alert protocol.
 184          * The format and meaning of the data value depends on the protocol.
 185          * For the SMBus alert protocol, there is a single bit of data passed
 186          * as the alert response's low bit ("event flag").
 187          */
 188         void (*alert)(struct i2c_client *, unsigned int data);
 189
 190         /* a ioctl like command that can be used to perform specific functions
 191          * with the device.
 192          */
 193         int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
 194
 195         struct device_driver driver;
 196         const struct i2c_device_id *id_table;
 197
 198         /* Device detection callback for automatic device creation */
 199         int (*detect)(struct i2c_client *, struct i2c_board_info *);
 200         const unsigned short *address_list;
 201         struct list_head clients;
 202 };
 203 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
 204
 205 /**
 206  * struct i2c_client - represent an I2C slave device
 207  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
 208  *      I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
 209  * @addr: Address used on the I2C bus connected to the parent adapter.
 210  * @name: Indicates the type of the device, usually a chip name that's
 211  *      generic enough to hide second-sourcing and compatible revisions.
 212  * @adapter: manages the bus segment hosting this I2C device
 213  * @driver: device's driver, hence pointer to access routines
 214  * @dev: Driver model device node for the slave.
 215  * @irq: indicates the IRQ generated by this device (if any)
 216  * @detected: member of an i2c_driver.clients list or i2c-core's
 217  *      userspace_devices list
 218  *
 219  * An i2c_client identifies a single device (i.e. chip) connected to an
 220  * i2c bus. The behaviour exposed to Linux is defined by the driver
 221  * managing the device.
 222  */
 223 struct i2c_client {
 224         unsigned short flags;           /* div., see below              */
 225         unsigned short addr;            /* chip address - NOTE: 7bit    */
 226                                         /* addresses are stored in the  */
 227                                         /* _LOWER_ 7 bits               */
 228         char name[I2C_NAME_SIZE];
 229         struct i2c_adapter *adapter;    /* the adapter we sit on        */
 230         struct i2c_driver *driver;      /* and our access routines      */
 231         struct device dev;              /* the device structure         */
 232         int irq;                        /* irq issued by device         */
 233         struct list_head detected;
 234 };
 235 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
 236
 237 extern struct i2c_client *i2c_verify_client(struct device *dev);
 238 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
 239
 240 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
 241 {
 242         struct device * const dev = container_of(kobj, struct device, kobj);
 243         return to_i2c_client(dev);
 244 }
 245
 246 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
 247 {
 248         return dev_get_drvdata(&dev->dev);
 249 }
 250
 251 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
 252 {
 253         dev_set_drvdata(&dev->dev, data);
 254 }
 255
 256 /**
 257  * struct i2c_board_info - template for device creation
 258  * @type: chip type, to initialize i2c_client.name
 259  * @flags: to initialize i2c_client.flags
 260  * @addr: stored in i2c_client.addr
 261  * @platform_data: stored in i2c_client.dev.platform_data
 262  * @archdata: copied into i2c_client.dev.archdata
 263  * @of_node: pointer to OpenFirmware device node
 264  * @irq: stored in i2c_client.irq
 265  *
 266  * I2C doesn't actually support hardware probing, although controllers and
 267  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
 268  * a device at a given address.  Drivers commonly need more information than
 269  * that, such as chip type, configuration, associated IRQ, and so on.
 270  *
 271  * i2c_board_info is used to build tables of information listing I2C devices
 272  * that are present.  This information is used to grow the driver model tree.
 273  * For mainboards this is done statically using i2c_register_board_info();
 274  * bus numbers identify adapters that aren't yet available.  For add-on boards,
 275  * i2c_new_device() does this dynamically with the adapter already known.
 276  */
 277 struct i2c_board_info {
 278         char            type[I2C_NAME_SIZE];
 279         unsigned short  flags;
 280         unsigned short  addr;
 281         void            *platform_data;
 282         struct dev_archdata     *archdata;
 283         struct device_node *of_node;
 284         int             irq;
 285 };
 286
 287 /**
 288  * I2C_BOARD_INFO - macro used to list an i2c device and its address
 289  * @dev_type: identifies the device type
 290  * @dev_addr: the device's address on the bus.
 291  *
 292  * This macro initializes essential fields of a struct i2c_board_info,
 293  * declaring what has been provided on a particular board.  Optional
 294  * fields (such as associated irq, or device-specific platform_data)
 295  * are provided using conventional syntax.
 296  */
 297 #define I2C_BOARD_INFO(dev_type, dev_addr) \
 298         .type = dev_type, .addr = (dev_addr)
 299
 300
 301 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
 302 /* Add-on boards should register/unregister their devices; e.g. a board
 303  * with integrated I2C, a config eeprom, sensors, and a codec that's
 304  * used in conjunction with the primary hardware.
 305  */
 306 extern struct i2c_client *
 307 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
 308
 309 /* If you don't know the exact address of an I2C device, use this variant
 310  * instead, which can probe for device presence in a list of possible
 311  * addresses. The "probe" callback function is optional. If it is provided,
 312  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
 313  * a default probing method is used.
 314  */
 315 extern struct i2c_client *
 316 i2c_new_probed_device(struct i2c_adapter *adap,
 317                       struct i2c_board_info *info,
 318                       unsigned short const *addr_list,
 319                       int (*probe)(struct i2c_adapter *, unsigned short addr));
 320
 321 /* Common custom probe functions */
 322 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
 323
 324 /* For devices that use several addresses, use i2c_new_dummy() to make
 325  * client handles for the extra addresses.
 326  */
 327 extern struct i2c_client *
 328 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
 329
 330 extern void i2c_unregister_device(struct i2c_client *);
 331 #endif /* I2C */
 332
 333 /* Mainboard arch_initcall() code should register all its I2C devices.
 334  * This is done at arch_initcall time, before declaring any i2c adapters.
 335  * Modules for add-on boards must use other calls.
 336  */
 337 #ifdef CONFIG_I2C_BOARDINFO
 338 extern int
 339 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 340                         unsigned n);
 341 #else
 342 static inline int
 343 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 344                         unsigned n)
 345 {
 346         return 0;
 347 }
 348 #endif /* I2C_BOARDINFO */
 349
 350 /*
 351  * The following structs are for those who like to implement new bus drivers:
 352  * i2c_algorithm is the interface to a class of hardware solutions which can
 353  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
 354  * to name two of the most common.
 355  */
 356 struct i2c_algorithm {
 357         /* If an adapter algorithm can't do I2C-level access, set master_xfer
 358            to NULL. If an adapter algorithm can do SMBus access, set
 359            smbus_xfer. If set to NULL, the SMBus protocol is simulated
 360            using common I2C messages */
 361         /* master_xfer should return the number of messages successfully
 362            processed, or a negative value on error */
 363         int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
 364                            int num);
 365         int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
 366                            unsigned short flags, char read_write,
 367                            u8 command, int size, union i2c_smbus_data *data);
 368
 369         /* To determine what the adapter supports */
 370         u32 (*functionality) (struct i2c_adapter *);
 371 };
 372
 373 /*
 374  * i2c_adapter is the structure used to identify a physical i2c bus along
 375  * with the access algorithms necessary to access it.
 376  */
 377 struct i2c_adapter {
 378         struct module *owner;
 379         unsigned int class;               /* classes to allow probing for */
 380         const struct i2c_algorithm *algo; /* the algorithm to access the bus */
 381         void *algo_data;
 382
 383         /* data fields that are valid for all devices   */
 384         struct rt_mutex bus_lock;
 385
 386         int timeout;                    /* in jiffies */
 387         int retries;
 388         struct device dev;              /* the adapter device */
 389
 390         int nr;
 391         char name[48];
 392         struct completion dev_released;
 393
 394         struct mutex userspace_clients_lock;
 395         struct list_head userspace_clients;
 396 };
 397 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
 398
 399 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
 400 {
 401         return dev_get_drvdata(&dev->dev);
 402 }
 403
 404 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
 405 {
 406         dev_set_drvdata(&dev->dev, data);
 407 }
 408
 409 static inline struct i2c_adapter *
 410 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 411 {
 412         struct device *parent = adapter->dev.parent;
 413
 414         if (parent != NULL && parent->type == &i2c_adapter_type)
 415                 return to_i2c_adapter(parent);
 416         else
 417                 return NULL;
 418 }
 419
 420 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
 421
 422 /* Adapter locking functions, exported for shared pin cases */
 423 void i2c_lock_adapter(struct i2c_adapter *);
 424 void i2c_unlock_adapter(struct i2c_adapter *);
 425
 426 /*flags for the client struct: */
 427 #define I2C_CLIENT_PEC  0x04            /* Use Packet Error Checking */
 428 #define I2C_CLIENT_TEN  0x10            /* we have a ten bit chip address */
 429                                         /* Must equal I2C_M_TEN below */
 430 #define I2C_CLIENT_WAKE 0x80            /* for board_info; true iff can wake */
 431 #define I2C_CLIENT_SCCB 0x9000          /* Use Omnivision SCCB protocol */
 432                                         /* Must match I2C_M_STOP|IGNORE_NAK */
 433
 434 /* i2c adapter classes (bitmask) */
 435 #define I2C_CLASS_HWMON         (1<<0)  /* lm_sensors, ... */
 436 #define I2C_CLASS_DDC           (1<<3)  /* DDC bus on graphics adapters */
 437 #define I2C_CLASS_SPD           (1<<7)  /* Memory modules */
 438
 439 /* Internal numbers to terminate lists */
 440 #define I2C_CLIENT_END          0xfffeU
 441
 442 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
 443 #define I2C_ADDRS(addr, addrs...) \
 444         ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
 445
 446
 447 /* ----- functions exported by i2c.o */
 448
 449 /* administration...
 450  */
 451 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
 452 extern int i2c_add_adapter(struct i2c_adapter *);
 453 extern int i2c_del_adapter(struct i2c_adapter *);
 454 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
 455
 456 extern int i2c_register_driver(struct module *, struct i2c_driver *);
 457 extern void i2c_del_driver(struct i2c_driver *);
 458
 459 /* use a define to avoid include chaining to get THIS_MODULE */
 460 #define i2c_add_driver(driver) \
 461         i2c_register_driver(THIS_MODULE, driver)
 462
 463 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
 464 extern void i2c_release_client(struct i2c_client *client);
 465
 466 /* call the i2c_client->command() of all attached clients with
 467  * the given arguments */
 468 extern void i2c_clients_command(struct i2c_adapter *adap,
 469                                 unsigned int cmd, void *arg);
 470
 471 extern struct i2c_adapter *i2c_get_adapter(int nr);
 472 extern void i2c_put_adapter(struct i2c_adapter *adap);
 473
 474
 475 /* Return the functionality mask */
 476 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
 477 {
 478         return adap->algo->functionality(adap);
 479 }
 480
 481 /* Return 1 if adapter supports everything we need, 0 if not. */
 482 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
 483 {
 484         return (func & i2c_get_functionality(adap)) == func;
 485 }
 486
 487 /* Return the adapter number for a specific adapter */
 488 static inline int i2c_adapter_id(struct i2c_adapter *adap)
 489 {
 490         return adap->nr;
 491 }
 492
 493 /**
 494  * module_i2c_driver() - Helper macro for registering a I2C driver
 495  * @__i2c_driver: i2c_driver struct
 496  *
 497  * Helper macro for I2C drivers which do not do anything special in module
 498  * init/exit. This eliminates a lot of boilerplate. Each module may only
 499  * use this macro once, and calling it replaces module_init() and module_exit()
 500  */
 501 #define module_i2c_driver(__i2c_driver) \
 502         module_driver(__i2c_driver, i2c_add_driver, \
 503                         i2c_del_driver)
 504
 505 #endif /* I2C */
 506 #endif /* __KERNEL__ */
 507
 508 /**
 509  * struct i2c_msg - an I2C transaction segment beginning with START
 510  * @addr: Slave address, either seven or ten bits.  When this is a ten
 511  *      bit address, I2C_M_TEN must be set in @flags and the adapter
 512  *      must support I2C_FUNC_10BIT_ADDR.
 513  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
 514  *      provided unless the adapter exported the relevant I2C_FUNC_*
 515  *      flags through i2c_check_functionality().
 516  * @len: Number of data bytes in @buf being read from or written to the
 517  *      I2C slave address.  For read transactions where I2C_M_RECV_LEN
 518  *      is set, the caller guarantees that this buffer can hold up to
 519  *      32 bytes in addition to the initial length byte sent by the
 520  *      slave (plus, if used, the SMBus PEC); and this value will be
 521  *      incremented by the number of block data bytes received.
 522  * @buf: The buffer into which data is read, or from which it's written.
 523  *
 524  * An i2c_msg is the low level representation of one segment of an I2C
 525  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
 526  * to userspace from i2c-dev, and to I2C adapter drivers through the
 527  * @i2c_adapter.@master_xfer() method.
 528  *
 529  * Except when I2C "protocol mangling" is used, all I2C adapters implement
 530  * the standard rules for I2C transactions.  Each transaction begins with a
 531  * START.  That is followed by the slave address, and a bit encoding read
 532  * versus write.  Then follow all the data bytes, possibly including a byte
 533  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
 534  * bytes have been transferred and ACKed.  If this is the last message in a
 535  * group, it is followed by a STOP.  Otherwise it is followed by the next
 536  * @i2c_msg transaction segment, beginning with a (repeated) START.
 537  *
 538  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
 539  * passing certain @flags may have changed those standard protocol behaviors.
 540  * Those flags are only for use with broken/nonconforming slaves, and with
 541  * adapters which are known to support the specific mangling options they
 542  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
 543  */
 544 struct i2c_msg {
 545         __u16 addr;     /* slave address                        */
 546         __u16 flags;
 547 #define I2C_M_TEN               0x0010  /* this is a ten bit chip address */
 548 #define I2C_M_RD                0x0001  /* read data, from slave to master */
 549 #define I2C_M_STOP              0x8000  /* if I2C_FUNC_PROTOCOL_MANGLING */
 550 #define I2C_M_NOSTART           0x4000  /* if I2C_FUNC_NOSTART */
 551 #define I2C_M_REV_DIR_ADDR      0x2000  /* if I2C_FUNC_PROTOCOL_MANGLING */
 552 #define I2C_M_IGNORE_NAK        0x1000  /* if I2C_FUNC_PROTOCOL_MANGLING */
 553 #define I2C_M_NO_RD_ACK         0x0800  /* if I2C_FUNC_PROTOCOL_MANGLING */
 554 #define I2C_M_RECV_LEN          0x0400  /* length will be first received byte */
 555         __u16 len;              /* msg length                           */
 556         __u8 *buf;              /* pointer to msg data                  */
 557 };
 558
 559 /* To determine what functionality is present */
 560
 561 #define I2C_FUNC_I2C                    0x00000001
 562 #define I2C_FUNC_10BIT_ADDR             0x00000002
 563 #define I2C_FUNC_PROTOCOL_MANGLING      0x00000004 /* I2C_M_IGNORE_NAK etc. */
 564 #define I2C_FUNC_SMBUS_PEC              0x00000008
 565 #define I2C_FUNC_NOSTART                0x00000010 /* I2C_M_NOSTART */
 566 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL  0x00008000 /* SMBus 2.0 */
 567 #define I2C_FUNC_SMBUS_QUICK            0x00010000
 568 #define I2C_FUNC_SMBUS_READ_BYTE        0x00020000
 569 #define I2C_FUNC_SMBUS_WRITE_BYTE       0x00040000
 570 #define I2C_FUNC_SMBUS_READ_BYTE_DATA   0x00080000
 571 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA  0x00100000
 572 #define I2C_FUNC_SMBUS_READ_WORD_DATA   0x00200000
 573 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA  0x00400000
 574 #define I2C_FUNC_SMBUS_PROC_CALL        0x00800000
 575 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA  0x01000000
 576 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
 577 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK   0x04000000 /* I2C-like block xfer  */
 578 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK  0x08000000 /* w/ 1-byte reg. addr. */
 579
 580 #define I2C_FUNC_SMBUS_BYTE             (I2C_FUNC_SMBUS_READ_BYTE | \
 581                                          I2C_FUNC_SMBUS_WRITE_BYTE)
 582 #define I2C_FUNC_SMBUS_BYTE_DATA        (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
 583                                          I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
 584 #define I2C_FUNC_SMBUS_WORD_DATA        (I2C_FUNC_SMBUS_READ_WORD_DATA | \
 585                                          I2C_FUNC_SMBUS_WRITE_WORD_DATA)
 586 #define I2C_FUNC_SMBUS_BLOCK_DATA       (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
 587                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
 588 #define I2C_FUNC_SMBUS_I2C_BLOCK        (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
 589                                          I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
 590
 591 #define I2C_FUNC_SMBUS_EMUL             (I2C_FUNC_SMBUS_QUICK | \
 592                                          I2C_FUNC_SMBUS_BYTE | \
 593                                          I2C_FUNC_SMBUS_BYTE_DATA | \
 594                                          I2C_FUNC_SMBUS_WORD_DATA | \
 595                                          I2C_FUNC_SMBUS_PROC_CALL | \
 596                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
 597                                          I2C_FUNC_SMBUS_I2C_BLOCK | \
 598                                          I2C_FUNC_SMBUS_PEC)
 599
 600 /*
 601  * Data for SMBus Messages
 602  */
 603 #define I2C_SMBUS_BLOCK_MAX     32      /* As specified in SMBus standard */
 604 union i2c_smbus_data {
 605         __u8 byte;
 606         __u16 word;
 607         __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
 608                                /* and one more for user-space compatibility */
 609 };
 610
 611 /* i2c_smbus_xfer read or write markers */
 612 #define I2C_SMBUS_READ  1
 613 #define I2C_SMBUS_WRITE 0
 614
 615 /* SMBus transaction types (size parameter in the above functions)
 616    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
 617 #define I2C_SMBUS_QUICK             0
 618 #define I2C_SMBUS_BYTE              1
 619 #define I2C_SMBUS_BYTE_DATA         2
 620 #define I2C_SMBUS_WORD_DATA         3
 621 #define I2C_SMBUS_PROC_CALL         4
 622 #define I2C_SMBUS_BLOCK_DATA        5
 623 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
 624 #define I2C_SMBUS_BLOCK_PROC_CALL   7           /* SMBus 2.0 */
 625 #define I2C_SMBUS_I2C_BLOCK_DATA    8
 626
 627 #endif /* _LINUX_I2C_H */