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 <[email protected]> and 24 Frodo Looijaard <[email protected]> */ 25 26 #ifndef _LINUX_I2C_H 27 #define _LINUX_I2C_H 28 29 #include <linux/types.h> 30 #ifdef __KERNEL__ 31 #include <linux/module.h> 32 #include <linux/i2c-id.h> 33 #include <linux/mod_devicetable.h> 34 #include <linux/device.h> /* for struct device */ 35 #include <linux/sched.h> /* for completion */ 36 #include <linux/mutex.h> 37 38 extern struct bus_type i2c_bus_type; 39 40 /* --- General options ------------------------------------------------ */ 41 42 struct i2c_msg; 43 struct i2c_algorithm; 44 struct i2c_adapter; 45 struct i2c_client; 46 struct i2c_driver; 47 union i2c_smbus_data; 48 struct i2c_board_info; 49 50 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 51 /* 52 * The master routines are the ones normally used to transmit data to devices 53 * on a bus (or read from them). Apart from two basic transfer functions to 54 * transmit one message at a time, a more complex version can be used to 55 * transmit an arbitrary number of messages without interruption. 56 */ 57 extern int i2c_master_send(struct i2c_client *client, const char *buf, 58 int count); 59 extern int i2c_master_recv(struct i2c_client *client, char *buf, int count); 60 61 /* Transfer num messages. 62 */ 63 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 64 int num); 65 66 /* This is the very generalized SMBus access routine. You probably do not 67 want to use this, though; one of the functions below may be much easier, 68 and probably just as fast. 69 Note that we use i2c_adapter here, because you do not need a specific 70 smbus adapter to call this function. */ 71 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 72 unsigned short flags, char read_write, u8 command, 73 int size, union i2c_smbus_data *data); 74 75 /* Now follow the 'nice' access routines. These also document the calling 76 conventions of i2c_smbus_xfer. */ 77 78 extern s32 i2c_smbus_read_byte(struct i2c_client *client); 79 extern s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value); 80 extern s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command); 81 extern s32 i2c_smbus_write_byte_data(struct i2c_client *client, 82 u8 command, u8 value); 83 extern s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command); 84 extern s32 i2c_smbus_write_word_data(struct i2c_client *client, 85 u8 command, u16 value); 86 /* Returns the number of read bytes */ 87 extern s32 i2c_smbus_read_block_data(struct i2c_client *client, 88 u8 command, u8 *values); 89 extern s32 i2c_smbus_write_block_data(struct i2c_client *client, 90 u8 command, u8 length, const u8 *values); 91 /* Returns the number of read bytes */ 92 extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, 93 u8 command, u8 length, u8 *values); 94 extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, 95 u8 command, u8 length, 96 const u8 *values); 97 #endif /* I2C */ 98 99 /** 100 * struct i2c_driver - represent an I2C device driver 101 * @class: What kind of i2c device we instantiate (for detect) 102 * @attach_adapter: Callback for bus addition (for legacy drivers) 103 * @detach_adapter: Callback for bus removal (for legacy drivers) 104 * @probe: Callback for device binding 105 * @remove: Callback for device unbinding 106 * @shutdown: Callback for device shutdown 107 * @suspend: Callback for device suspend 108 * @resume: Callback for device resume 109 * @command: Callback for bus-wide signaling (optional) 110 * @driver: Device driver model driver 111 * @id_table: List of I2C devices supported by this driver 112 * @detect: Callback for device detection 113 * @address_list: The I2C addresses to probe (for detect) 114 * @clients: List of detected clients we created (for i2c-core use only) 115 * 116 * The driver.owner field should be set to the module owner of this driver. 117 * The driver.name field should be set to the name of this driver. 118 * 119 * For automatic device detection, both @detect and @address_data must 120 * be defined. @class should also be set, otherwise only devices forced 121 * with module parameters will be created. The detect function must 122 * fill at least the name field of the i2c_board_info structure it is 123 * handed upon successful detection, and possibly also the flags field. 124 * 125 * If @detect is missing, the driver will still work fine for enumerated 126 * devices. Detected devices simply won't be supported. This is expected 127 * for the many I2C/SMBus devices which can't be detected reliably, and 128 * the ones which can always be enumerated in practice. 129 * 130 * The i2c_client structure which is handed to the @detect callback is 131 * not a real i2c_client. It is initialized just enough so that you can 132 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 133 * else with it. In particular, calling dev_dbg and friends on it is 134 * not allowed. 135 */ 136 struct i2c_driver { 137 unsigned int class; 138 139 /* Notifies the driver that a new bus has appeared or is about to be 140 * removed. You should avoid using this if you can, it will probably 141 * be removed in a near future. 142 */ 143 int (*attach_adapter)(struct i2c_adapter *); 144 int (*detach_adapter)(struct i2c_adapter *); 145 146 /* Standard driver model interfaces */ 147 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 148 int (*remove)(struct i2c_client *); 149 150 /* driver model interfaces that don't relate to enumeration */ 151 void (*shutdown)(struct i2c_client *); 152 int (*suspend)(struct i2c_client *, pm_message_t mesg); 153 int (*resume)(struct i2c_client *); 154 155 /* a ioctl like command that can be used to perform specific functions 156 * with the device. 157 */ 158 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 159 160 struct device_driver driver; 161 const struct i2c_device_id *id_table; 162 163 /* Device detection callback for automatic device creation */ 164 int (*detect)(struct i2c_client *, struct i2c_board_info *); 165 const unsigned short *address_list; 166 struct list_head clients; 167 }; 168 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 169 170 /** 171 * struct i2c_client - represent an I2C slave device 172 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 173 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 174 * @addr: Address used on the I2C bus connected to the parent adapter. 175 * @name: Indicates the type of the device, usually a chip name that's 176 * generic enough to hide second-sourcing and compatible revisions. 177 * @adapter: manages the bus segment hosting this I2C device 178 * @driver: device's driver, hence pointer to access routines 179 * @dev: Driver model device node for the slave. 180 * @irq: indicates the IRQ generated by this device (if any) 181 * @detected: member of an i2c_driver.clients list or i2c-core's 182 * userspace_devices list 183 * 184 * An i2c_client identifies a single device (i.e. chip) connected to an 185 * i2c bus. The behaviour exposed to Linux is defined by the driver 186 * managing the device. 187 */ 188 struct i2c_client { 189 unsigned short flags; /* div., see below */ 190 unsigned short addr; /* chip address - NOTE: 7bit */ 191 /* addresses are stored in the */ 192 /* _LOWER_ 7 bits */ 193 char name[I2C_NAME_SIZE]; 194 struct i2c_adapter *adapter; /* the adapter we sit on */ 195 struct i2c_driver *driver; /* and our access routines */ 196 struct device dev; /* the device structure */ 197 int irq; /* irq issued by device */ 198 struct list_head detected; 199 }; 200 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 201 202 extern struct i2c_client *i2c_verify_client(struct device *dev); 203 204 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 205 { 206 struct device * const dev = container_of(kobj, struct device, kobj); 207 return to_i2c_client(dev); 208 } 209 210 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 211 { 212 return dev_get_drvdata(&dev->dev); 213 } 214 215 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 216 { 217 dev_set_drvdata(&dev->dev, data); 218 } 219 220 /** 221 * struct i2c_board_info - template for device creation 222 * @type: chip type, to initialize i2c_client.name 223 * @flags: to initialize i2c_client.flags 224 * @addr: stored in i2c_client.addr 225 * @platform_data: stored in i2c_client.dev.platform_data 226 * @archdata: copied into i2c_client.dev.archdata 227 * @irq: stored in i2c_client.irq 228 * 229 * I2C doesn't actually support hardware probing, although controllers and 230 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 231 * a device at a given address. Drivers commonly need more information than 232 * that, such as chip type, configuration, associated IRQ, and so on. 233 * 234 * i2c_board_info is used to build tables of information listing I2C devices 235 * that are present. This information is used to grow the driver model tree. 236 * For mainboards this is done statically using i2c_register_board_info(); 237 * bus numbers identify adapters that aren't yet available. For add-on boards, 238 * i2c_new_device() does this dynamically with the adapter already known. 239 */ 240 struct i2c_board_info { 241 char type[I2C_NAME_SIZE]; 242 unsigned short flags; 243 unsigned short addr; 244 void *platform_data; 245 struct dev_archdata *archdata; 246 int irq; 247 }; 248 249 /** 250 * I2C_BOARD_INFO - macro used to list an i2c device and its address 251 * @dev_type: identifies the device type 252 * @dev_addr: the device's address on the bus. 253 * 254 * This macro initializes essential fields of a struct i2c_board_info, 255 * declaring what has been provided on a particular board. Optional 256 * fields (such as associated irq, or device-specific platform_data) 257 * are provided using conventional syntax. 258 */ 259 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 260 .type = dev_type, .addr = (dev_addr) 261 262 263 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 264 /* Add-on boards should register/unregister their devices; e.g. a board 265 * with integrated I2C, a config eeprom, sensors, and a codec that's 266 * used in conjunction with the primary hardware. 267 */ 268 extern struct i2c_client * 269 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 270 271 /* If you don't know the exact address of an I2C device, use this variant 272 * instead, which can probe for device presence in a list of possible 273 * addresses. 274 */ 275 extern struct i2c_client * 276 i2c_new_probed_device(struct i2c_adapter *adap, 277 struct i2c_board_info *info, 278 unsigned short const *addr_list); 279 280 /* For devices that use several addresses, use i2c_new_dummy() to make 281 * client handles for the extra addresses. 282 */ 283 extern struct i2c_client * 284 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 285 286 extern void i2c_unregister_device(struct i2c_client *); 287 #endif /* I2C */ 288 289 /* Mainboard arch_initcall() code should register all its I2C devices. 290 * This is done at arch_initcall time, before declaring any i2c adapters. 291 * Modules for add-on boards must use other calls. 292 */ 293 #ifdef CONFIG_I2C_BOARDINFO 294 extern int 295 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 296 unsigned n); 297 #else 298 static inline int 299 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 300 unsigned n) 301 { 302 return 0; 303 } 304 #endif /* I2C_BOARDINFO */ 305 306 /* 307 * The following structs are for those who like to implement new bus drivers: 308 * i2c_algorithm is the interface to a class of hardware solutions which can 309 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 310 * to name two of the most common. 311 */ 312 struct i2c_algorithm { 313 /* If an adapter algorithm can't do I2C-level access, set master_xfer 314 to NULL. If an adapter algorithm can do SMBus access, set 315 smbus_xfer. If set to NULL, the SMBus protocol is simulated 316 using common I2C messages */ 317 /* master_xfer should return the number of messages successfully 318 processed, or a negative value on error */ 319 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 320 int num); 321 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 322 unsigned short flags, char read_write, 323 u8 command, int size, union i2c_smbus_data *data); 324 325 /* To determine what the adapter supports */ 326 u32 (*functionality) (struct i2c_adapter *); 327 }; 328 329 /* 330 * i2c_adapter is the structure used to identify a physical i2c bus along 331 * with the access algorithms necessary to access it. 332 */ 333 struct i2c_adapter { 334 struct module *owner; 335 unsigned int id; 336 unsigned int class; /* classes to allow probing for */ 337 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 338 void *algo_data; 339 340 /* data fields that are valid for all devices */ 341 struct rt_mutex bus_lock; 342 343 int timeout; /* in jiffies */ 344 int retries; 345 struct device dev; /* the adapter device */ 346 347 int nr; 348 char name[48]; 349 struct completion dev_released; 350 }; 351 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 352 353 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 354 { 355 return dev_get_drvdata(&dev->dev); 356 } 357 358 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 359 { 360 dev_set_drvdata(&dev->dev, data); 361 } 362 363 /** 364 * i2c_lock_adapter - Prevent access to an I2C bus segment 365 * @adapter: Target I2C bus segment 366 */ 367 static inline void i2c_lock_adapter(struct i2c_adapter *adapter) 368 { 369 rt_mutex_lock(&adapter->bus_lock); 370 } 371 372 /** 373 * i2c_unlock_adapter - Reauthorize access to an I2C bus segment 374 * @adapter: Target I2C bus segment 375 */ 376 static inline void i2c_unlock_adapter(struct i2c_adapter *adapter) 377 { 378 rt_mutex_unlock(&adapter->bus_lock); 379 } 380 381 /*flags for the client struct: */ 382 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 383 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 384 /* Must equal I2C_M_TEN below */ 385 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 386 387 /* i2c adapter classes (bitmask) */ 388 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 389 #define I2C_CLASS_TV_ANALOG (1<<1) /* bttv + friends */ 390 #define I2C_CLASS_TV_DIGITAL (1<<2) /* dvb cards */ 391 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 392 #define I2C_CLASS_SPD (1<<7) /* SPD EEPROMs and similar */ 393 394 /* Internal numbers to terminate lists */ 395 #define I2C_CLIENT_END 0xfffeU 396 397 /* The numbers to use to set I2C bus address */ 398 #define ANY_I2C_BUS 0xffff 399 400 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 401 #define I2C_ADDRS(addr, addrs...) \ 402 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 403 404 405 /* ----- functions exported by i2c.o */ 406 407 /* administration... 408 */ 409 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 410 extern int i2c_add_adapter(struct i2c_adapter *); 411 extern int i2c_del_adapter(struct i2c_adapter *); 412 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 413 414 extern int i2c_register_driver(struct module *, struct i2c_driver *); 415 extern void i2c_del_driver(struct i2c_driver *); 416 417 static inline int i2c_add_driver(struct i2c_driver *driver) 418 { 419 return i2c_register_driver(THIS_MODULE, driver); 420 } 421 422 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 423 extern void i2c_release_client(struct i2c_client *client); 424 425 /* call the i2c_client->command() of all attached clients with 426 * the given arguments */ 427 extern void i2c_clients_command(struct i2c_adapter *adap, 428 unsigned int cmd, void *arg); 429 430 extern struct i2c_adapter *i2c_get_adapter(int id); 431 extern void i2c_put_adapter(struct i2c_adapter *adap); 432 433 434 /* Return the functionality mask */ 435 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 436 { 437 return adap->algo->functionality(adap); 438 } 439 440 /* Return 1 if adapter supports everything we need, 0 if not. */ 441 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 442 { 443 return (func & i2c_get_functionality(adap)) == func; 444 } 445 446 /* Return the adapter number for a specific adapter */ 447 static inline int i2c_adapter_id(struct i2c_adapter *adap) 448 { 449 return adap->nr; 450 } 451 #endif /* I2C */ 452 #endif /* __KERNEL__ */ 453 454 /** 455 * struct i2c_msg - an I2C transaction segment beginning with START 456 * @addr: Slave address, either seven or ten bits. When this is a ten 457 * bit address, I2C_M_TEN must be set in @flags and the adapter 458 * must support I2C_FUNC_10BIT_ADDR. 459 * @flags: I2C_M_RD is handled by all adapters. No other flags may be 460 * provided unless the adapter exported the relevant I2C_FUNC_* 461 * flags through i2c_check_functionality(). 462 * @len: Number of data bytes in @buf being read from or written to the 463 * I2C slave address. For read transactions where I2C_M_RECV_LEN 464 * is set, the caller guarantees that this buffer can hold up to 465 * 32 bytes in addition to the initial length byte sent by the 466 * slave (plus, if used, the SMBus PEC); and this value will be 467 * incremented by the number of block data bytes received. 468 * @buf: The buffer into which data is read, or from which it's written. 469 * 470 * An i2c_msg is the low level representation of one segment of an I2C 471 * transaction. It is visible to drivers in the @i2c_transfer() procedure, 472 * to userspace from i2c-dev, and to I2C adapter drivers through the 473 * @i2c_adapter.@master_xfer() method. 474 * 475 * Except when I2C "protocol mangling" is used, all I2C adapters implement 476 * the standard rules for I2C transactions. Each transaction begins with a 477 * START. That is followed by the slave address, and a bit encoding read 478 * versus write. Then follow all the data bytes, possibly including a byte 479 * with SMBus PEC. The transfer terminates with a NAK, or when all those 480 * bytes have been transferred and ACKed. If this is the last message in a 481 * group, it is followed by a STOP. Otherwise it is followed by the next 482 * @i2c_msg transaction segment, beginning with a (repeated) START. 483 * 484 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then 485 * passing certain @flags may have changed those standard protocol behaviors. 486 * Those flags are only for use with broken/nonconforming slaves, and with 487 * adapters which are known to support the specific mangling options they 488 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR). 489 */ 490 struct i2c_msg { 491 __u16 addr; /* slave address */ 492 __u16 flags; 493 #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ 494 #define I2C_M_RD 0x0001 /* read data, from slave to master */ 495 #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */ 496 #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */ 497 #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ 498 #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ 499 #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ 500 __u16 len; /* msg length */ 501 __u8 *buf; /* pointer to msg data */ 502 }; 503 504 /* To determine what functionality is present */ 505 506 #define I2C_FUNC_I2C 0x00000001 507 #define I2C_FUNC_10BIT_ADDR 0x00000002 508 #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */ 509 #define I2C_FUNC_SMBUS_PEC 0x00000008 510 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */ 511 #define I2C_FUNC_SMBUS_QUICK 0x00010000 512 #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000 513 #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000 514 #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000 515 #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000 516 #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000 517 #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000 518 #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000 519 #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000 520 #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 521 #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */ 522 #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */ 523 524 #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \ 525 I2C_FUNC_SMBUS_WRITE_BYTE) 526 #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \ 527 I2C_FUNC_SMBUS_WRITE_BYTE_DATA) 528 #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \ 529 I2C_FUNC_SMBUS_WRITE_WORD_DATA) 530 #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \ 531 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) 532 #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \ 533 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK) 534 535 #define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \ 536 I2C_FUNC_SMBUS_BYTE | \ 537 I2C_FUNC_SMBUS_BYTE_DATA | \ 538 I2C_FUNC_SMBUS_WORD_DATA | \ 539 I2C_FUNC_SMBUS_PROC_CALL | \ 540 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \ 541 I2C_FUNC_SMBUS_I2C_BLOCK | \ 542 I2C_FUNC_SMBUS_PEC) 543 544 /* 545 * Data for SMBus Messages 546 */ 547 #define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */ 548 union i2c_smbus_data { 549 __u8 byte; 550 __u16 word; 551 __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */ 552 /* and one more for user-space compatibility */ 553 }; 554 555 /* i2c_smbus_xfer read or write markers */ 556 #define I2C_SMBUS_READ 1 557 #define I2C_SMBUS_WRITE 0 558 559 /* SMBus transaction types (size parameter in the above functions) 560 Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */ 561 #define I2C_SMBUS_QUICK 0 562 #define I2C_SMBUS_BYTE 1 563 #define I2C_SMBUS_BYTE_DATA 2 564 #define I2C_SMBUS_WORD_DATA 3 565 #define I2C_SMBUS_PROC_CALL 4 566 #define I2C_SMBUS_BLOCK_DATA 5 567 #define I2C_SMBUS_I2C_BLOCK_BROKEN 6 568 #define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */ 569 #define I2C_SMBUS_I2C_BLOCK_DATA 8 570 571 #endif /* _LINUX_I2C_H */ 572