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., 675 Mass Ave, Cambridge, MA 02139, USA.                */
  21 /* ------------------------------------------------------------------------- */
  22
  23 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
  24    Frodo Looijaard <frodol@dds.nl> */
  25
  26 #ifndef _LINUX_I2C_H
  27 #define _LINUX_I2C_H
  28
  29 #include <linux/types.h>
  30 #ifdef __KERNEL__
  31 #include <linux/mod_devicetable.h>
  32 #include <linux/device.h>       /* for struct device */
  33 #include <linux/sched.h>        /* for completion */
  34 #include <linux/mutex.h>
  35 #include <linux/of.h>           /* for struct device_node */
  36 #include <linux/swab.h>         /* for swab16 */
  37
  38 extern struct bus_type i2c_bus_type;
  39 extern struct device_type i2c_adapter_type;
  40
  41 /* --- General options ------------------------------------------------ */
  42
  43 struct i2c_msg;
  44 struct i2c_algorithm;
  45 struct i2c_adapter;
  46 struct i2c_client;
  47 struct i2c_driver;
  48 union i2c_smbus_data;
  49 struct i2c_board_info;
  50
  51 struct module;
  52
  53 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
  54 /*
  55  * The master routines are the ones normally used to transmit data to devices
  56  * on a bus (or read from them). Apart from two basic transfer functions to
  57  * transmit one message at a time, a more complex version can be used to
  58  * transmit an arbitrary number of messages without interruption.
  59  * @count must be be less than 64k since msg.len is u16.
  60  */
  61 extern int i2c_master_send(const struct i2c_client *client, const char *buf,
  62                            int count);
  63 extern int i2c_master_recv(const struct i2c_client *client, char *buf,
  64                            int count);
  65
  66 /* Transfer num messages.
  67  */
  68 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  69                         int num);
  70
  71 /* This is the very generalized SMBus access routine. You probably do not
  72    want to use this, though; one of the functions below may be much easier,
  73    and probably just as fast.
  74    Note that we use i2c_adapter here, because you do not need a specific
  75    smbus adapter to call this function. */
  76 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
  77                           unsigned short flags, char read_write, u8 command,
  78                           int size, union i2c_smbus_data *data);
  79
  80 /* Now follow the 'nice' access routines. These also document the calling
  81    conventions of i2c_smbus_xfer. */
  82
  83 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
  84 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
  85 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
  86                                     u8 command);
  87 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
  88                                      u8 command, u8 value);
  89 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
  90                                     u8 command);
  91 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
  92                                      u8 command, u16 value);
  93
  94 static inline s32
  95 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
  96 {
  97         s32 value = i2c_smbus_read_word_data(client, command);
  98
  99         return (value < 0) ? value : swab16(value);
 100 }
 101
 102 static inline s32
 103 i2c_smbus_write_word_swapped(const struct i2c_client *client,
 104                              u8 command, u16 value)
 105 {
 106         return i2c_smbus_write_word_data(client, command, swab16(value));
 107 }
 108
 109 /* Returns the number of read bytes */
 110 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
 111                                      u8 command, u8 *values);
 112 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
 113                                       u8 command, u8 length, const u8 *values);
 114 /* Returns the number of read bytes */
 115 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
 116                                          u8 command, u8 length, u8 *values);
 117 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
 118                                           u8 command, u8 length,
 119                                           const u8 *values);
 120 #endif /* I2C */
 121
 122 /**
 123  * struct i2c_driver - represent an I2C device driver
 124  * @class: What kind of i2c device we instantiate (for detect)
 125  * @attach_adapter: Callback for bus addition (deprecated)
 126  * @detach_adapter: Callback for bus removal (deprecated)
 127  * @probe: Callback for device binding
 128  * @remove: Callback for device unbinding
 129  * @shutdown: Callback for device shutdown
 130  * @suspend: Callback for device suspend
 131  * @resume: Callback for device resume
 132  * @alert: Alert callback, for example for the SMBus alert protocol
 133  * @command: Callback for bus-wide signaling (optional)
 134  * @driver: Device driver model driver
 135  * @id_table: List of I2C devices supported by this driver
 136  * @detect: Callback for device detection
 137  * @address_list: The I2C addresses to probe (for detect)
 138  * @clients: List of detected clients we created (for i2c-core use only)
 139  *
 140  * The driver.owner field should be set to the module owner of this driver.
 141  * The driver.name field should be set to the name of this driver.
 142  *
 143  * For automatic device detection, both @detect and @address_data must
 144  * be defined. @class should also be set, otherwise only devices forced
 145  * with module parameters will be created. The detect function must
 146  * fill at least the name field of the i2c_board_info structure it is
 147  * handed upon successful detection, and possibly also the flags field.
 148  *
 149  * If @detect is missing, the driver will still work fine for enumerated
 150  * devices. Detected devices simply won't be supported. This is expected
 151  * for the many I2C/SMBus devices which can't be detected reliably, and
 152  * the ones which can always be enumerated in practice.
 153  *
 154  * The i2c_client structure which is handed to the @detect callback is
 155  * not a real i2c_client. It is initialized just enough so that you can
 156  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
 157  * else with it. In particular, calling dev_dbg and friends on it is
 158  * not allowed.
 159  */
 160 struct i2c_driver {
 161         unsigned int class;
 162
 163         /* Notifies the driver that a new bus has appeared or is about to be
 164          * removed. You should avoid using this, it will be removed in a
 165          * near future.
 166          */
 167         int (*attach_adapter)(struct i2c_adapter *) __deprecated;
 168         int (*detach_adapter)(struct i2c_adapter *) __deprecated;
 169
 170         /* Standard driver model interfaces */
 171         int (*probe)(struct i2c_client *, const struct i2c_device_id *);
 172         int (*remove)(struct i2c_client *);
 173
 174         /* driver model interfaces that don't relate to enumeration  */
 175         void (*shutdown)(struct i2c_client *);
 176         int (*suspend)(struct i2c_client *, pm_message_t mesg);
 177         int (*resume)(struct i2c_client *);
 178
 179         /* Alert callback, for example for the SMBus alert protocol.
 180          * The format and meaning of the data value depends on the protocol.
 181          * For the SMBus alert protocol, there is a single bit of data passed
 182          * as the alert response's low bit ("event flag").
 183          */
 184         void (*alert)(struct i2c_client *, unsigned int data);
 185
 186         /* a ioctl like command that can be used to perform specific functions
 187          * with the device.
 188          */
 189         int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
 190
 191         struct device_driver driver;
 192         const struct i2c_device_id *id_table;
 193
 194         /* Device detection callback for automatic device creation */
 195         int (*detect)(struct i2c_client *, struct i2c_board_info *);
 196         const unsigned short *address_list;
 197         struct list_head clients;
 198 };
 199 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
 200
 201 /**
 202  * struct i2c_client - represent an I2C slave device
 203  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
 204  *      I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
 205  * @addr: Address used on the I2C bus connected to the parent adapter.
 206  * @name: Indicates the type of the device, usually a chip name that's
 207  *      generic enough to hide second-sourcing and compatible revisions.
 208  * @adapter: manages the bus segment hosting this I2C device
 209  * @driver: device's driver, hence pointer to access routines
 210  * @dev: Driver model device node for the slave.
 211  * @irq: indicates the IRQ generated by this device (if any)
 212  * @detected: member of an i2c_driver.clients list or i2c-core's
 213  *      userspace_devices list
 214  *
 215  * An i2c_client identifies a single device (i.e. chip) connected to an
 216  * i2c bus. The behaviour exposed to Linux is defined by the driver
 217  * managing the device.
 218  */
 219 struct i2c_client {
 220         unsigned short flags;           /* div., see below              */
 221         unsigned short addr;            /* chip address - NOTE: 7bit    */
 222                                         /* addresses are stored in the  */
 223                                         /* _LOWER_ 7 bits               */
 224         char name[I2C_NAME_SIZE];
 225         struct i2c_adapter *adapter;    /* the adapter we sit on        */
 226         struct i2c_driver *driver;      /* and our access routines      */
 227         struct device dev;              /* the device structure         */
 228         int irq;                        /* irq issued by device         */
 229         struct list_head detected;
 230 };
 231 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
 232
 233 extern struct i2c_client *i2c_verify_client(struct device *dev);
 234
 235 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
 236 {
 237         struct device * const dev = container_of(kobj, struct device, kobj);
 238         return to_i2c_client(dev);
 239 }
 240
 241 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
 242 {
 243         return dev_get_drvdata(&dev->dev);
 244 }
 245
 246 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
 247 {
 248         dev_set_drvdata(&dev->dev, data);
 249 }
 250
 251 /**
 252  * struct i2c_board_info - template for device creation
 253  * @type: chip type, to initialize i2c_client.name
 254  * @flags: to initialize i2c_client.flags
 255  * @addr: stored in i2c_client.addr
 256  * @platform_data: stored in i2c_client.dev.platform_data
 257  * @archdata: copied into i2c_client.dev.archdata
 258  * @of_node: pointer to OpenFirmware device node
 259  * @irq: stored in i2c_client.irq
 260  *
 261  * I2C doesn't actually support hardware probing, although controllers and
 262  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
 263  * a device at a given address.  Drivers commonly need more information than
 264  * that, such as chip type, configuration, associated IRQ, and so on.
 265  *
 266  * i2c_board_info is used to build tables of information listing I2C devices
 267  * that are present.  This information is used to grow the driver model tree.
 268  * For mainboards this is done statically using i2c_register_board_info();
 269  * bus numbers identify adapters that aren't yet available.  For add-on boards,
 270  * i2c_new_device() does this dynamically with the adapter already known.
 271  */
 272 struct i2c_board_info {
 273         char            type[I2C_NAME_SIZE];
 274         unsigned short  flags;
 275         unsigned short  addr;
 276         void            *platform_data;
 277         struct dev_archdata     *archdata;
 278         struct device_node *of_node;
 279         int             irq;
 280 };
 281
 282 /**
 283  * I2C_BOARD_INFO - macro used to list an i2c device and its address
 284  * @dev_type: identifies the device type
 285  * @dev_addr: the device's address on the bus.
 286  *
 287  * This macro initializes essential fields of a struct i2c_board_info,
 288  * declaring what has been provided on a particular board.  Optional
 289  * fields (such as associated irq, or device-specific platform_data)
 290  * are provided using conventional syntax.
 291  */
 292 #define I2C_BOARD_INFO(dev_type, dev_addr) \
 293         .type = dev_type, .addr = (dev_addr)
 294
 295
 296 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
 297 /* Add-on boards should register/unregister their devices; e.g. a board
 298  * with integrated I2C, a config eeprom, sensors, and a codec that's
 299  * used in conjunction with the primary hardware.
 300  */
 301 extern struct i2c_client *
 302 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
 303
 304 /* If you don't know the exact address of an I2C device, use this variant
 305  * instead, which can probe for device presence in a list of possible
 306  * addresses. The "probe" callback function is optional. If it is provided,
 307  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
 308  * a default probing method is used.
 309  */
 310 extern struct i2c_client *
 311 i2c_new_probed_device(struct i2c_adapter *adap,
 312                       struct i2c_board_info *info,
 313                       unsigned short const *addr_list,
 314                       int (*probe)(struct i2c_adapter *, unsigned short addr));
 315
 316 /* Common custom probe functions */
 317 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
 318
 319 /* For devices that use several addresses, use i2c_new_dummy() to make
 320  * client handles for the extra addresses.
 321  */
 322 extern struct i2c_client *
 323 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
 324
 325 extern void i2c_unregister_device(struct i2c_client *);
 326 #endif /* I2C */
 327
 328 /* Mainboard arch_initcall() code should register all its I2C devices.
 329  * This is done at arch_initcall time, before declaring any i2c adapters.
 330  * Modules for add-on boards must use other calls.
 331  */
 332 #ifdef CONFIG_I2C_BOARDINFO
 333 extern int
 334 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 335                         unsigned n);
 336 #else
 337 static inline int
 338 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 339                         unsigned n)
 340 {
 341         return 0;
 342 }
 343 #endif /* I2C_BOARDINFO */
 344
 345 /*
 346  * The following structs are for those who like to implement new bus drivers:
 347  * i2c_algorithm is the interface to a class of hardware solutions which can
 348  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
 349  * to name two of the most common.
 350  */
 351 struct i2c_algorithm {
 352         /* If an adapter algorithm can't do I2C-level access, set master_xfer
 353            to NULL. If an adapter algorithm can do SMBus access, set
 354            smbus_xfer. If set to NULL, the SMBus protocol is simulated
 355            using common I2C messages */
 356         /* master_xfer should return the number of messages successfully
 357            processed, or a negative value on error */
 358         int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
 359                            int num);
 360         int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
 361                            unsigned short flags, char read_write,
 362                            u8 command, int size, union i2c_smbus_data *data);
 363
 364         /* To determine what the adapter supports */
 365         u32 (*functionality) (struct i2c_adapter *);
 366 };
 367
 368 /*
 369  * i2c_adapter is the structure used to identify a physical i2c bus along
 370  * with the access algorithms necessary to access it.
 371  */
 372 struct i2c_adapter {
 373         struct module *owner;
 374         unsigned int class;               /* classes to allow probing for */
 375         const struct i2c_algorithm *algo; /* the algorithm to access the bus */
 376         void *algo_data;
 377
 378         /* data fields that are valid for all devices   */
 379         struct rt_mutex bus_lock;
 380
 381         int timeout;                    /* in jiffies */
 382         int retries;
 383         struct device dev;              /* the adapter device */
 384
 385         int nr;
 386         char name[48];
 387         struct completion dev_released;
 388
 389         struct mutex userspace_clients_lock;
 390         struct list_head userspace_clients;
 391 };
 392 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
 393
 394 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
 395 {
 396         return dev_get_drvdata(&dev->dev);
 397 }
 398
 399 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
 400 {
 401         dev_set_drvdata(&dev->dev, data);
 402 }
 403
 404 static inline struct i2c_adapter *
 405 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 406 {
 407         struct device *parent = adapter->dev.parent;
 408
 409         if (parent != NULL && parent->type == &i2c_adapter_type)
 410                 return to_i2c_adapter(parent);
 411         else
 412                 return NULL;
 413 }
 414
 415 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
 416
 417 /* Adapter locking functions, exported for shared pin cases */
 418 void i2c_lock_adapter(struct i2c_adapter *);
 419 void i2c_unlock_adapter(struct i2c_adapter *);
 420
 421 /*flags for the client struct: */
 422 #define I2C_CLIENT_PEC  0x04            /* Use Packet Error Checking */
 423 #define I2C_CLIENT_TEN  0x10            /* we have a ten bit chip address */
 424                                         /* Must equal I2C_M_TEN below */
 425 #define I2C_CLIENT_WAKE 0x80            /* for board_info; true iff can wake */
 426
 427 /* i2c adapter classes (bitmask) */
 428 #define I2C_CLASS_HWMON         (1<<0)  /* lm_sensors, ... */
 429 #define I2C_CLASS_DDC           (1<<3)  /* DDC bus on graphics adapters */
 430 #define I2C_CLASS_SPD           (1<<7)  /* Memory modules */
 431
 432 /* Internal numbers to terminate lists */
 433 #define I2C_CLIENT_END          0xfffeU
 434
 435 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
 436 #define I2C_ADDRS(addr, addrs...) \
 437         ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
 438
 439
 440 /* ----- functions exported by i2c.o */
 441
 442 /* administration...
 443  */
 444 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
 445 extern int i2c_add_adapter(struct i2c_adapter *);
 446 extern int i2c_del_adapter(struct i2c_adapter *);
 447 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
 448
 449 extern int i2c_register_driver(struct module *, struct i2c_driver *);
 450 extern void i2c_del_driver(struct i2c_driver *);
 451
 452 /* use a define to avoid include chaining to get THIS_MODULE */
 453 #define i2c_add_driver(driver) \
 454         i2c_register_driver(THIS_MODULE, driver)
 455
 456 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
 457 extern void i2c_release_client(struct i2c_client *client);
 458
 459 /* call the i2c_client->command() of all attached clients with
 460  * the given arguments */
 461 extern void i2c_clients_command(struct i2c_adapter *adap,
 462                                 unsigned int cmd, void *arg);
 463
 464 extern struct i2c_adapter *i2c_get_adapter(int nr);
 465 extern void i2c_put_adapter(struct i2c_adapter *adap);
 466
 467
 468 /* Return the functionality mask */
 469 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
 470 {
 471         return adap->algo->functionality(adap);
 472 }
 473
 474 /* Return 1 if adapter supports everything we need, 0 if not. */
 475 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
 476 {
 477         return (func & i2c_get_functionality(adap)) == func;
 478 }
 479
 480 /* Return the adapter number for a specific adapter */
 481 static inline int i2c_adapter_id(struct i2c_adapter *adap)
 482 {
 483         return adap->nr;
 484 }
 485
 486 /**
 487  * module_i2c_driver() - Helper macro for registering a I2C driver
 488  * @__i2c_driver: i2c_driver struct
 489  *
 490  * Helper macro for I2C drivers which do not do anything special in module
 491  * init/exit. This eliminates a lot of boilerplate. Each module may only
 492  * use this macro once, and calling it replaces module_init() and module_exit()
 493  */
 494 #define module_i2c_driver(__i2c_driver) \
 495         module_driver(__i2c_driver, i2c_add_driver, \
 496                         i2c_del_driver)
 497
 498 #endif /* I2C */
 499 #endif /* __KERNEL__ */
 500
 501 /**
 502  * struct i2c_msg - an I2C transaction segment beginning with START
 503  * @addr: Slave address, either seven or ten bits.  When this is a ten
 504  *      bit address, I2C_M_TEN must be set in @flags and the adapter
 505  *      must support I2C_FUNC_10BIT_ADDR.
 506  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
 507  *      provided unless the adapter exported the relevant I2C_FUNC_*
 508  *      flags through i2c_check_functionality().
 509  * @len: Number of data bytes in @buf being read from or written to the
 510  *      I2C slave address.  For read transactions where I2C_M_RECV_LEN
 511  *      is set, the caller guarantees that this buffer can hold up to
 512  *      32 bytes in addition to the initial length byte sent by the
 513  *      slave (plus, if used, the SMBus PEC); and this value will be
 514  *      incremented by the number of block data bytes received.
 515  * @buf: The buffer into which data is read, or from which it's written.
 516  *
 517  * An i2c_msg is the low level representation of one segment of an I2C
 518  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
 519  * to userspace from i2c-dev, and to I2C adapter drivers through the
 520  * @i2c_adapter.@master_xfer() method.
 521  *
 522  * Except when I2C "protocol mangling" is used, all I2C adapters implement
 523  * the standard rules for I2C transactions.  Each transaction begins with a
 524  * START.  That is followed by the slave address, and a bit encoding read
 525  * versus write.  Then follow all the data bytes, possibly including a byte
 526  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
 527  * bytes have been transferred and ACKed.  If this is the last message in a
 528  * group, it is followed by a STOP.  Otherwise it is followed by the next
 529  * @i2c_msg transaction segment, beginning with a (repeated) START.
 530  *
 531  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
 532  * passing certain @flags may have changed those standard protocol behaviors.
 533  * Those flags are only for use with broken/nonconforming slaves, and with
 534  * adapters which are known to support the specific mangling options they
 535  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
 536  */
 537 struct i2c_msg {
 538         __u16 addr;     /* slave address                        */
 539         __u16 flags;
 540 #define I2C_M_TEN               0x0010  /* this is a ten bit chip address */
 541 #define I2C_M_RD                0x0001  /* read data, from slave to master */
 542 #define I2C_M_NOSTART           0x4000  /* if I2C_FUNC_PROTOCOL_MANGLING */
 543 #define I2C_M_REV_DIR_ADDR      0x2000  /* if I2C_FUNC_PROTOCOL_MANGLING */
 544 #define I2C_M_IGNORE_NAK        0x1000  /* if I2C_FUNC_PROTOCOL_MANGLING */
 545 #define I2C_M_NO_RD_ACK         0x0800  /* if I2C_FUNC_PROTOCOL_MANGLING */
 546 #define I2C_M_RECV_LEN          0x0400  /* length will be first received byte */
 547         __u16 len;              /* msg length                           */
 548         __u8 *buf;              /* pointer to msg data                  */
 549 };
 550
 551 /* To determine what functionality is present */
 552
 553 #define I2C_FUNC_I2C                    0x00000001
 554 #define I2C_FUNC_10BIT_ADDR             0x00000002
 555 #define I2C_FUNC_PROTOCOL_MANGLING      0x00000004 /* I2C_M_NOSTART etc. */
 556 #define I2C_FUNC_SMBUS_PEC              0x00000008
 557 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL  0x00008000 /* SMBus 2.0 */
 558 #define I2C_FUNC_SMBUS_QUICK            0x00010000
 559 #define I2C_FUNC_SMBUS_READ_BYTE        0x00020000
 560 #define I2C_FUNC_SMBUS_WRITE_BYTE       0x00040000
 561 #define I2C_FUNC_SMBUS_READ_BYTE_DATA   0x00080000
 562 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA  0x00100000
 563 #define I2C_FUNC_SMBUS_READ_WORD_DATA   0x00200000
 564 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA  0x00400000
 565 #define I2C_FUNC_SMBUS_PROC_CALL        0x00800000
 566 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA  0x01000000
 567 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
 568 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK   0x04000000 /* I2C-like block xfer  */
 569 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK  0x08000000 /* w/ 1-byte reg. addr. */
 570
 571 #define I2C_FUNC_SMBUS_BYTE             (I2C_FUNC_SMBUS_READ_BYTE | \
 572                                          I2C_FUNC_SMBUS_WRITE_BYTE)
 573 #define I2C_FUNC_SMBUS_BYTE_DATA        (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
 574                                          I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
 575 #define I2C_FUNC_SMBUS_WORD_DATA        (I2C_FUNC_SMBUS_READ_WORD_DATA | \
 576                                          I2C_FUNC_SMBUS_WRITE_WORD_DATA)
 577 #define I2C_FUNC_SMBUS_BLOCK_DATA       (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
 578                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
 579 #define I2C_FUNC_SMBUS_I2C_BLOCK        (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
 580                                          I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
 581
 582 #define I2C_FUNC_SMBUS_EMUL             (I2C_FUNC_SMBUS_QUICK | \
 583                                          I2C_FUNC_SMBUS_BYTE | \
 584                                          I2C_FUNC_SMBUS_BYTE_DATA | \
 585                                          I2C_FUNC_SMBUS_WORD_DATA | \
 586                                          I2C_FUNC_SMBUS_PROC_CALL | \
 587                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
 588                                          I2C_FUNC_SMBUS_I2C_BLOCK | \
 589                                          I2C_FUNC_SMBUS_PEC)
 590
 591 /*
 592  * Data for SMBus Messages
 593  */
 594 #define I2C_SMBUS_BLOCK_MAX     32      /* As specified in SMBus standard */
 595 union i2c_smbus_data {
 596         __u8 byte;
 597         __u16 word;
 598         __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
 599                                /* and one more for user-space compatibility */
 600 };
 601
 602 /* i2c_smbus_xfer read or write markers */
 603 #define I2C_SMBUS_READ  1
 604 #define I2C_SMBUS_WRITE 0
 605
 606 /* SMBus transaction types (size parameter in the above functions)
 607    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
 608 #define I2C_SMBUS_QUICK             0
 609 #define I2C_SMBUS_BYTE              1
 610 #define I2C_SMBUS_BYTE_DATA         2
 611 #define I2C_SMBUS_WORD_DATA         3
 612 #define I2C_SMBUS_PROC_CALL         4
 613 #define I2C_SMBUS_BLOCK_DATA        5
 614 #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
 615 #define I2C_SMBUS_BLOCK_PROC_CALL   7           /* SMBus 2.0 */
 616 #define I2C_SMBUS_I2C_BLOCK_DATA    8
 617
 618 #endif /* _LINUX_I2C_H */