linux/include/linux/i2c.h
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   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
  39extern struct bus_type i2c_bus_type;
  40extern struct device_type i2c_adapter_type;
  41
  42/* --- General options ------------------------------------------------ */
  43
  44struct i2c_msg;
  45struct i2c_algorithm;
  46struct i2c_adapter;
  47struct i2c_client;
  48struct i2c_driver;
  49union i2c_smbus_data;
  50struct i2c_board_info;
  51
  52struct 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 */
  62extern int i2c_master_send(const struct i2c_client *client, const char *buf,
  63                           int count);
  64extern int i2c_master_recv(const struct i2c_client *client, char *buf,
  65                           int count);
  66
  67/* Transfer num messages.
  68 */
  69extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  70                        int num);
  71/* Unlocked flavor */
  72extern 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. */
  80extern 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
  87extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
  88extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
  89extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
  90                                    u8 command);
  91extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
  92                                     u8 command, u8 value);
  93extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
  94                                    u8 command);
  95extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
  96                                     u8 command, u16 value);
  97
  98static inline s32
  99i2c_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
 106static inline s32
 107i2c_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 */
 114extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
 115                                     u8 command, u8 *values);
 116extern 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 */
 119extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
 120                                         u8 command, u8 length, u8 *values);
 121extern 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 */
 164struct 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 */
 223struct 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
 237extern struct i2c_client *i2c_verify_client(struct device *dev);
 238extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
 239
 240static 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
 246static inline void *i2c_get_clientdata(const struct i2c_client *dev)
 247{
 248        return dev_get_drvdata(&dev->dev);
 249}
 250
 251static 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 */
 277struct 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 */
 306extern struct i2c_client *
 307i2c_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 */
 315extern struct i2c_client *
 316i2c_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 */
 322extern 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 */
 327extern struct i2c_client *
 328i2c_new_dummy(struct i2c_adapter *adap, u16 address);
 329
 330extern 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
 338extern int
 339i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 340                        unsigned n);
 341#else
 342static inline int
 343i2c_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 */
 356struct 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 */
 377struct 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
 399static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
 400{
 401        return dev_get_drvdata(&dev->dev);
 402}
 403
 404static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
 405{
 406        dev_set_drvdata(&dev->dev, data);
 407}
 408
 409static inline struct i2c_adapter *
 410i2c_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
 420int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
 421
 422/* Adapter locking functions, exported for shared pin cases */
 423void i2c_lock_adapter(struct i2c_adapter *);
 424void 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)
 452extern int i2c_add_adapter(struct i2c_adapter *);
 453extern int i2c_del_adapter(struct i2c_adapter *);
 454extern int i2c_add_numbered_adapter(struct i2c_adapter *);
 455
 456extern int i2c_register_driver(struct module *, struct i2c_driver *);
 457extern 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
 463extern struct i2c_client *i2c_use_client(struct i2c_client *client);
 464extern void i2c_release_client(struct i2c_client *client);
 465
 466/* call the i2c_client->command() of all attached clients with
 467 * the given arguments */
 468extern void i2c_clients_command(struct i2c_adapter *adap,
 469                                unsigned int cmd, void *arg);
 470
 471extern struct i2c_adapter *i2c_get_adapter(int nr);
 472extern void i2c_put_adapter(struct i2c_adapter *adap);
 473
 474
 475/* Return the functionality mask */
 476static 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. */
 482static 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 */
 488static 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 */
 544struct 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 */
 604union 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 */
 628
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