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 <[email protected]> and 25 Frodo Looijaard <[email protected]> */ 26 #ifndef _LINUX_I2C_H 27 #define _LINUX_I2C_H 28 29 #include <linux/mod_devicetable.h> 30 #include <linux/device.h> /* for struct device */ 31 #include <linux/sched.h> /* for completion */ 32 #include <linux/mutex.h> 33 #include <linux/of.h> /* for struct device_node */ 34 #include <linux/swab.h> /* for swab16 */ 35 #include <uapi/linux/i2c.h> 36 37 extern struct bus_type i2c_bus_type; 38 extern struct device_type i2c_adapter_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 struct module; 51 52 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 53 /* 54 * The master routines are the ones normally used to transmit data to devices 55 * on a bus (or read from them). Apart from two basic transfer functions to 56 * transmit one message at a time, a more complex version can be used to 57 * transmit an arbitrary number of messages without interruption. 58 * @count must be be less than 64k since msg.len is u16. 59 */ 60 extern int i2c_master_send(const struct i2c_client *client, const char *buf, 61 int count); 62 extern int i2c_master_recv(const struct i2c_client *client, char *buf, 63 int count); 64 65 /* Transfer num messages. 66 */ 67 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 68 int num); 69 /* Unlocked flavor */ 70 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 71 int num); 72 73 /* This is the very generalized SMBus access routine. You probably do not 74 want to use this, though; one of the functions below may be much easier, 75 and probably just as fast. 76 Note that we use i2c_adapter here, because you do not need a specific 77 smbus adapter to call this function. */ 78 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 79 unsigned short flags, char read_write, u8 command, 80 int size, union i2c_smbus_data *data); 81 82 /* Now follow the 'nice' access routines. These also document the calling 83 conventions of i2c_smbus_xfer. */ 84 85 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 86 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 87 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 88 u8 command); 89 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 90 u8 command, u8 value); 91 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 92 u8 command); 93 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 94 u8 command, u16 value); 95 96 static inline s32 97 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 98 { 99 s32 value = i2c_smbus_read_word_data(client, command); 100 101 return (value < 0) ? value : swab16(value); 102 } 103 104 static inline s32 105 i2c_smbus_write_word_swapped(const struct i2c_client *client, 106 u8 command, u16 value) 107 { 108 return i2c_smbus_write_word_data(client, command, swab16(value)); 109 } 110 111 /* Returns the number of read bytes */ 112 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 113 u8 command, u8 *values); 114 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 115 u8 command, u8 length, const u8 *values); 116 /* Returns the number of read bytes */ 117 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 118 u8 command, u8 length, u8 *values); 119 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 120 u8 command, u8 length, 121 const u8 *values); 122 #endif /* I2C */ 123 124 /** 125 * struct i2c_driver - represent an I2C device driver 126 * @class: What kind of i2c device we instantiate (for detect) 127 * @attach_adapter: Callback for bus addition (deprecated) 128 * @detach_adapter: Callback for bus removal (deprecated) 129 * @probe: Callback for device binding 130 * @remove: Callback for device unbinding 131 * @shutdown: Callback for device shutdown 132 * @suspend: Callback for device suspend 133 * @resume: Callback for device resume 134 * @alert: Alert callback, for example for the SMBus alert protocol 135 * @command: Callback for bus-wide signaling (optional) 136 * @driver: Device driver model driver 137 * @id_table: List of I2C devices supported by this driver 138 * @detect: Callback for device detection 139 * @address_list: The I2C addresses to probe (for detect) 140 * @clients: List of detected clients we created (for i2c-core use only) 141 * 142 * The driver.owner field should be set to the module owner of this driver. 143 * The driver.name field should be set to the name of this driver. 144 * 145 * For automatic device detection, both @detect and @address_list must 146 * be defined. @class should also be set, otherwise only devices forced 147 * with module parameters will be created. The detect function must 148 * fill at least the name field of the i2c_board_info structure it is 149 * handed upon successful detection, and possibly also the flags field. 150 * 151 * If @detect is missing, the driver will still work fine for enumerated 152 * devices. Detected devices simply won't be supported. This is expected 153 * for the many I2C/SMBus devices which can't be detected reliably, and 154 * the ones which can always be enumerated in practice. 155 * 156 * The i2c_client structure which is handed to the @detect callback is 157 * not a real i2c_client. It is initialized just enough so that you can 158 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 159 * else with it. In particular, calling dev_dbg and friends on it is 160 * not allowed. 161 */ 162 struct i2c_driver { 163 unsigned int class; 164 165 /* Notifies the driver that a new bus has appeared or is about to be 166 * removed. You should avoid using this, it will be removed in a 167 * near future. 168 */ 169 int (*attach_adapter)(struct i2c_adapter *) __deprecated; 170 int (*detach_adapter)(struct i2c_adapter *) __deprecated; 171 172 /* Standard driver model interfaces */ 173 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 174 int (*remove)(struct i2c_client *); 175 176 /* driver model interfaces that don't relate to enumeration */ 177 void (*shutdown)(struct i2c_client *); 178 int (*suspend)(struct i2c_client *, pm_message_t mesg); 179 int (*resume)(struct i2c_client *); 180 181 /* Alert callback, for example for the SMBus alert protocol. 182 * The format and meaning of the data value depends on the protocol. 183 * For the SMBus alert protocol, there is a single bit of data passed 184 * as the alert response's low bit ("event flag"). 185 */ 186 void (*alert)(struct i2c_client *, unsigned int data); 187 188 /* a ioctl like command that can be used to perform specific functions 189 * with the device. 190 */ 191 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 192 193 struct device_driver driver; 194 const struct i2c_device_id *id_table; 195 196 /* Device detection callback for automatic device creation */ 197 int (*detect)(struct i2c_client *, struct i2c_board_info *); 198 const unsigned short *address_list; 199 struct list_head clients; 200 }; 201 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 202 203 /** 204 * struct i2c_client - represent an I2C slave device 205 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 206 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 207 * @addr: Address used on the I2C bus connected to the parent adapter. 208 * @name: Indicates the type of the device, usually a chip name that's 209 * generic enough to hide second-sourcing and compatible revisions. 210 * @adapter: manages the bus segment hosting this I2C device 211 * @driver: device's driver, hence pointer to access routines 212 * @dev: Driver model device node for the slave. 213 * @irq: indicates the IRQ generated by this device (if any) 214 * @detected: member of an i2c_driver.clients list or i2c-core's 215 * userspace_devices list 216 * 217 * An i2c_client identifies a single device (i.e. chip) connected to an 218 * i2c bus. The behaviour exposed to Linux is defined by the driver 219 * managing the device. 220 */ 221 struct i2c_client { 222 unsigned short flags; /* div., see below */ 223 unsigned short addr; /* chip address - NOTE: 7bit */ 224 /* addresses are stored in the */ 225 /* _LOWER_ 7 bits */ 226 char name[I2C_NAME_SIZE]; 227 struct i2c_adapter *adapter; /* the adapter we sit on */ 228 struct i2c_driver *driver; /* and our access routines */ 229 struct device dev; /* the device structure */ 230 int irq; /* irq issued by device */ 231 struct list_head detected; 232 }; 233 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 234 235 extern struct i2c_client *i2c_verify_client(struct device *dev); 236 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 237 238 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 239 { 240 struct device * const dev = container_of(kobj, struct device, kobj); 241 return to_i2c_client(dev); 242 } 243 244 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 245 { 246 return dev_get_drvdata(&dev->dev); 247 } 248 249 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 250 { 251 dev_set_drvdata(&dev->dev, data); 252 } 253 254 /** 255 * struct i2c_board_info - template for device creation 256 * @type: chip type, to initialize i2c_client.name 257 * @flags: to initialize i2c_client.flags 258 * @addr: stored in i2c_client.addr 259 * @platform_data: stored in i2c_client.dev.platform_data 260 * @archdata: copied into i2c_client.dev.archdata 261 * @of_node: pointer to OpenFirmware device node 262 * @irq: stored in i2c_client.irq 263 * 264 * I2C doesn't actually support hardware probing, although controllers and 265 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 266 * a device at a given address. Drivers commonly need more information than 267 * that, such as chip type, configuration, associated IRQ, and so on. 268 * 269 * i2c_board_info is used to build tables of information listing I2C devices 270 * that are present. This information is used to grow the driver model tree. 271 * For mainboards this is done statically using i2c_register_board_info(); 272 * bus numbers identify adapters that aren't yet available. For add-on boards, 273 * i2c_new_device() does this dynamically with the adapter already known. 274 */ 275 struct i2c_board_info { 276 char type[I2C_NAME_SIZE]; 277 unsigned short flags; 278 unsigned short addr; 279 void *platform_data; 280 struct dev_archdata *archdata; 281 struct device_node *of_node; 282 int irq; 283 }; 284 285 /** 286 * I2C_BOARD_INFO - macro used to list an i2c device and its address 287 * @dev_type: identifies the device type 288 * @dev_addr: the device's address on the bus. 289 * 290 * This macro initializes essential fields of a struct i2c_board_info, 291 * declaring what has been provided on a particular board. Optional 292 * fields (such as associated irq, or device-specific platform_data) 293 * are provided using conventional syntax. 294 */ 295 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 296 .type = dev_type, .addr = (dev_addr) 297 298 299 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 300 /* Add-on boards should register/unregister their devices; e.g. a board 301 * with integrated I2C, a config eeprom, sensors, and a codec that's 302 * used in conjunction with the primary hardware. 303 */ 304 extern struct i2c_client * 305 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 306 307 /* If you don't know the exact address of an I2C device, use this variant 308 * instead, which can probe for device presence in a list of possible 309 * addresses. The "probe" callback function is optional. If it is provided, 310 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 311 * a default probing method is used. 312 */ 313 extern struct i2c_client * 314 i2c_new_probed_device(struct i2c_adapter *adap, 315 struct i2c_board_info *info, 316 unsigned short const *addr_list, 317 int (*probe)(struct i2c_adapter *, unsigned short addr)); 318 319 /* Common custom probe functions */ 320 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 321 322 /* For devices that use several addresses, use i2c_new_dummy() to make 323 * client handles for the extra addresses. 324 */ 325 extern struct i2c_client * 326 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 327 328 extern void i2c_unregister_device(struct i2c_client *); 329 #endif /* I2C */ 330 331 /* Mainboard arch_initcall() code should register all its I2C devices. 332 * This is done at arch_initcall time, before declaring any i2c adapters. 333 * Modules for add-on boards must use other calls. 334 */ 335 #ifdef CONFIG_I2C_BOARDINFO 336 extern int 337 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 338 unsigned n); 339 #else 340 static inline int 341 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 342 unsigned n) 343 { 344 return 0; 345 } 346 #endif /* I2C_BOARDINFO */ 347 348 /* 349 * The following structs are for those who like to implement new bus drivers: 350 * i2c_algorithm is the interface to a class of hardware solutions which can 351 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 352 * to name two of the most common. 353 */ 354 struct i2c_algorithm { 355 /* If an adapter algorithm can't do I2C-level access, set master_xfer 356 to NULL. If an adapter algorithm can do SMBus access, set 357 smbus_xfer. If set to NULL, the SMBus protocol is simulated 358 using common I2C messages */ 359 /* master_xfer should return the number of messages successfully 360 processed, or a negative value on error */ 361 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 362 int num); 363 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 364 unsigned short flags, char read_write, 365 u8 command, int size, union i2c_smbus_data *data); 366 367 /* To determine what the adapter supports */ 368 u32 (*functionality) (struct i2c_adapter *); 369 }; 370 371 /* 372 * i2c_adapter is the structure used to identify a physical i2c bus along 373 * with the access algorithms necessary to access it. 374 */ 375 struct i2c_adapter { 376 struct module *owner; 377 unsigned int class; /* classes to allow probing for */ 378 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 379 void *algo_data; 380 381 /* data fields that are valid for all devices */ 382 struct rt_mutex bus_lock; 383 384 int timeout; /* in jiffies */ 385 int retries; 386 struct device dev; /* the adapter device */ 387 388 int nr; 389 char name[48]; 390 struct completion dev_released; 391 392 struct mutex userspace_clients_lock; 393 struct list_head userspace_clients; 394 }; 395 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 396 397 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 398 { 399 return dev_get_drvdata(&dev->dev); 400 } 401 402 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 403 { 404 dev_set_drvdata(&dev->dev, data); 405 } 406 407 static inline struct i2c_adapter * 408 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 409 { 410 struct device *parent = adapter->dev.parent; 411 412 if (parent != NULL && parent->type == &i2c_adapter_type) 413 return to_i2c_adapter(parent); 414 else 415 return NULL; 416 } 417 418 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 419 420 /* Adapter locking functions, exported for shared pin cases */ 421 void i2c_lock_adapter(struct i2c_adapter *); 422 void i2c_unlock_adapter(struct i2c_adapter *); 423 424 /*flags for the client struct: */ 425 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 426 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 427 /* Must equal I2C_M_TEN below */ 428 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 429 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 430 /* Must match I2C_M_STOP|IGNORE_NAK */ 431 432 /* i2c adapter classes (bitmask) */ 433 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 434 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 435 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 436 437 /* Internal numbers to terminate lists */ 438 #define I2C_CLIENT_END 0xfffeU 439 440 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 441 #define I2C_ADDRS(addr, addrs...) \ 442 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 443 444 445 /* ----- functions exported by i2c.o */ 446 447 /* administration... 448 */ 449 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 450 extern int i2c_add_adapter(struct i2c_adapter *); 451 extern int i2c_del_adapter(struct i2c_adapter *); 452 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 453 454 extern int i2c_register_driver(struct module *, struct i2c_driver *); 455 extern void i2c_del_driver(struct i2c_driver *); 456 457 /* use a define to avoid include chaining to get THIS_MODULE */ 458 #define i2c_add_driver(driver) \ 459 i2c_register_driver(THIS_MODULE, driver) 460 461 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 462 extern void i2c_release_client(struct i2c_client *client); 463 464 /* call the i2c_client->command() of all attached clients with 465 * the given arguments */ 466 extern void i2c_clients_command(struct i2c_adapter *adap, 467 unsigned int cmd, void *arg); 468 469 extern struct i2c_adapter *i2c_get_adapter(int nr); 470 extern void i2c_put_adapter(struct i2c_adapter *adap); 471 472 473 /* Return the functionality mask */ 474 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 475 { 476 return adap->algo->functionality(adap); 477 } 478 479 /* Return 1 if adapter supports everything we need, 0 if not. */ 480 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 481 { 482 return (func & i2c_get_functionality(adap)) == func; 483 } 484 485 /* Return the adapter number for a specific adapter */ 486 static inline int i2c_adapter_id(struct i2c_adapter *adap) 487 { 488 return adap->nr; 489 } 490 491 /** 492 * module_i2c_driver() - Helper macro for registering a I2C driver 493 * @__i2c_driver: i2c_driver struct 494 * 495 * Helper macro for I2C drivers which do not do anything special in module 496 * init/exit. This eliminates a lot of boilerplate. Each module may only 497 * use this macro once, and calling it replaces module_init() and module_exit() 498 */ 499 #define module_i2c_driver(__i2c_driver) \ 500 module_driver(__i2c_driver, i2c_add_driver, \ 501 i2c_del_driver) 502 503 #endif /* I2C */ 504 #endif /* _LINUX_I2C_H */ 505