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 #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 enum i2c_slave_event; 50 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 51 52 struct module; 53 54 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 55 /* 56 * The master routines are the ones normally used to transmit data to devices 57 * on a bus (or read from them). Apart from two basic transfer functions to 58 * transmit one message at a time, a more complex version can be used to 59 * transmit an arbitrary number of messages without interruption. 60 * @count must be be less than 64k since msg.len is u16. 61 */ 62 extern int i2c_master_send(const struct i2c_client *client, const char *buf, 63 int count); 64 extern int i2c_master_recv(const struct i2c_client *client, char *buf, 65 int count); 66 67 /* Transfer num messages. 68 */ 69 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 70 int num); 71 /* Unlocked flavor */ 72 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 73 int num); 74 75 /* This is the very generalized SMBus access routine. You probably do not 76 want to use this, though; one of the functions below may be much easier, 77 and probably just as fast. 78 Note that we use i2c_adapter here, because you do not need a specific 79 smbus adapter to call this function. */ 80 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 81 unsigned short flags, char read_write, u8 command, 82 int size, union i2c_smbus_data *data); 83 84 /* Now follow the 'nice' access routines. These also document the calling 85 conventions of i2c_smbus_xfer. */ 86 87 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 88 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 89 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 90 u8 command); 91 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 92 u8 command, u8 value); 93 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 94 u8 command); 95 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 96 u8 command, u16 value); 97 98 static inline s32 99 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 100 { 101 s32 value = i2c_smbus_read_word_data(client, command); 102 103 return (value < 0) ? value : swab16(value); 104 } 105 106 static inline s32 107 i2c_smbus_write_word_swapped(const struct i2c_client *client, 108 u8 command, u16 value) 109 { 110 return i2c_smbus_write_word_data(client, command, swab16(value)); 111 } 112 113 /* Returns the number of read bytes */ 114 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 115 u8 command, u8 *values); 116 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 117 u8 command, u8 length, const u8 *values); 118 /* Returns the number of read bytes */ 119 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 120 u8 command, u8 length, u8 *values); 121 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 122 u8 command, u8 length, 123 const u8 *values); 124 extern s32 125 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 126 u8 command, u8 length, u8 *values); 127 #endif /* I2C */ 128 129 /** 130 * struct i2c_driver - represent an I2C device driver 131 * @class: What kind of i2c device we instantiate (for detect) 132 * @attach_adapter: Callback for bus addition (deprecated) 133 * @probe: Callback for device binding 134 * @remove: Callback for device unbinding 135 * @shutdown: Callback for device shutdown 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_list must 148 * be defined. @class should also be set, otherwise only devices forced 149 * with module parameters will be created. The detect function must 150 * fill at least the name field of the i2c_board_info structure it is 151 * handed upon successful detection, and possibly also the flags field. 152 * 153 * If @detect is missing, the driver will still work fine for enumerated 154 * devices. Detected devices simply won't be supported. This is expected 155 * for the many I2C/SMBus devices which can't be detected reliably, and 156 * the ones which can always be enumerated in practice. 157 * 158 * The i2c_client structure which is handed to the @detect callback is 159 * not a real i2c_client. It is initialized just enough so that you can 160 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 161 * else with it. In particular, calling dev_dbg and friends on it is 162 * not allowed. 163 */ 164 struct i2c_driver { 165 unsigned int class; 166 167 /* Notifies the driver that a new bus has appeared. You should avoid 168 * using this, it will be removed in a near future. 169 */ 170 int (*attach_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 *); 178 179 /* 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 * @dev: Driver model device node for the slave. 210 * @irq: indicates the IRQ generated by this device (if any) 211 * @detected: member of an i2c_driver.clients list or i2c-core's 212 * userspace_devices list 213 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 214 * calls it to pass on slave events to the slave driver. 215 * 216 * An i2c_client identifies a single device (i.e. chip) connected to an 217 * i2c bus. The behaviour exposed to Linux is defined by the driver 218 * managing the device. 219 */ 220 struct i2c_client { 221 unsigned short flags; /* div., see below */ 222 unsigned short addr; /* chip address - NOTE: 7bit */ 223 /* addresses are stored in the */ 224 /* _LOWER_ 7 bits */ 225 char name[I2C_NAME_SIZE]; 226 struct i2c_adapter *adapter; /* the adapter we sit on */ 227 struct device dev; /* the device structure */ 228 int irq; /* irq issued by device */ 229 struct list_head detected; 230 #if IS_ENABLED(CONFIG_I2C_SLAVE) 231 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 232 #endif 233 }; 234 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 235 236 extern struct i2c_client *i2c_verify_client(struct device *dev); 237 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 238 239 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 240 { 241 struct device * const dev = container_of(kobj, struct device, kobj); 242 return to_i2c_client(dev); 243 } 244 245 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 246 { 247 return dev_get_drvdata(&dev->dev); 248 } 249 250 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 251 { 252 dev_set_drvdata(&dev->dev, data); 253 } 254 255 /* I2C slave support */ 256 257 #if IS_ENABLED(CONFIG_I2C_SLAVE) 258 enum i2c_slave_event { 259 I2C_SLAVE_READ_REQUESTED, 260 I2C_SLAVE_WRITE_REQUESTED, 261 I2C_SLAVE_READ_PROCESSED, 262 I2C_SLAVE_WRITE_RECEIVED, 263 I2C_SLAVE_STOP, 264 }; 265 266 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 267 extern int i2c_slave_unregister(struct i2c_client *client); 268 269 static inline int i2c_slave_event(struct i2c_client *client, 270 enum i2c_slave_event event, u8 *val) 271 { 272 return client->slave_cb(client, event, val); 273 } 274 #endif 275 276 /** 277 * struct i2c_board_info - template for device creation 278 * @type: chip type, to initialize i2c_client.name 279 * @flags: to initialize i2c_client.flags 280 * @addr: stored in i2c_client.addr 281 * @platform_data: stored in i2c_client.dev.platform_data 282 * @archdata: copied into i2c_client.dev.archdata 283 * @of_node: pointer to OpenFirmware device node 284 * @fwnode: device node supplied by the platform firmware 285 * @irq: stored in i2c_client.irq 286 * 287 * I2C doesn't actually support hardware probing, although controllers and 288 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 289 * a device at a given address. Drivers commonly need more information than 290 * that, such as chip type, configuration, associated IRQ, and so on. 291 * 292 * i2c_board_info is used to build tables of information listing I2C devices 293 * that are present. This information is used to grow the driver model tree. 294 * For mainboards this is done statically using i2c_register_board_info(); 295 * bus numbers identify adapters that aren't yet available. For add-on boards, 296 * i2c_new_device() does this dynamically with the adapter already known. 297 */ 298 struct i2c_board_info { 299 char type[I2C_NAME_SIZE]; 300 unsigned short flags; 301 unsigned short addr; 302 void *platform_data; 303 struct dev_archdata *archdata; 304 struct device_node *of_node; 305 struct fwnode_handle *fwnode; 306 int irq; 307 }; 308 309 /** 310 * I2C_BOARD_INFO - macro used to list an i2c device and its address 311 * @dev_type: identifies the device type 312 * @dev_addr: the device's address on the bus. 313 * 314 * This macro initializes essential fields of a struct i2c_board_info, 315 * declaring what has been provided on a particular board. Optional 316 * fields (such as associated irq, or device-specific platform_data) 317 * are provided using conventional syntax. 318 */ 319 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 320 .type = dev_type, .addr = (dev_addr) 321 322 323 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 324 /* Add-on boards should register/unregister their devices; e.g. a board 325 * with integrated I2C, a config eeprom, sensors, and a codec that's 326 * used in conjunction with the primary hardware. 327 */ 328 extern struct i2c_client * 329 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 330 331 /* If you don't know the exact address of an I2C device, use this variant 332 * instead, which can probe for device presence in a list of possible 333 * addresses. The "probe" callback function is optional. If it is provided, 334 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 335 * a default probing method is used. 336 */ 337 extern struct i2c_client * 338 i2c_new_probed_device(struct i2c_adapter *adap, 339 struct i2c_board_info *info, 340 unsigned short const *addr_list, 341 int (*probe)(struct i2c_adapter *, unsigned short addr)); 342 343 /* Common custom probe functions */ 344 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 345 346 /* For devices that use several addresses, use i2c_new_dummy() to make 347 * client handles for the extra addresses. 348 */ 349 extern struct i2c_client * 350 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 351 352 extern void i2c_unregister_device(struct i2c_client *); 353 #endif /* I2C */ 354 355 /* Mainboard arch_initcall() code should register all its I2C devices. 356 * This is done at arch_initcall time, before declaring any i2c adapters. 357 * Modules for add-on boards must use other calls. 358 */ 359 #ifdef CONFIG_I2C_BOARDINFO 360 extern int 361 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 362 unsigned n); 363 #else 364 static inline int 365 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 366 unsigned n) 367 { 368 return 0; 369 } 370 #endif /* I2C_BOARDINFO */ 371 372 /** 373 * struct i2c_algorithm - represent I2C transfer method 374 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 375 * defined by the msgs array, with num messages available to transfer via 376 * the adapter specified by adap. 377 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 378 * is not present, then the bus layer will try and convert the SMBus calls 379 * into I2C transfers instead. 380 * @functionality: Return the flags that this algorithm/adapter pair supports 381 * from the I2C_FUNC_* flags. 382 * @reg_slave: Register given client to I2C slave mode of this adapter 383 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 384 * 385 * The following structs are for those who like to implement new bus drivers: 386 * i2c_algorithm is the interface to a class of hardware solutions which can 387 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 388 * to name two of the most common. 389 * 390 * The return codes from the @master_xfer field should indicate the type of 391 * error code that occurred during the transfer, as documented in the kernel 392 * Documentation file Documentation/i2c/fault-codes. 393 */ 394 struct i2c_algorithm { 395 /* If an adapter algorithm can't do I2C-level access, set master_xfer 396 to NULL. If an adapter algorithm can do SMBus access, set 397 smbus_xfer. If set to NULL, the SMBus protocol is simulated 398 using common I2C messages */ 399 /* master_xfer should return the number of messages successfully 400 processed, or a negative value on error */ 401 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 402 int num); 403 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 404 unsigned short flags, char read_write, 405 u8 command, int size, union i2c_smbus_data *data); 406 407 /* To determine what the adapter supports */ 408 u32 (*functionality) (struct i2c_adapter *); 409 410 #if IS_ENABLED(CONFIG_I2C_SLAVE) 411 int (*reg_slave)(struct i2c_client *client); 412 int (*unreg_slave)(struct i2c_client *client); 413 #endif 414 }; 415 416 /** 417 * struct i2c_timings - I2C timing information 418 * @bus_freq_hz: the bus frequency in Hz 419 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 420 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 421 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 422 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 423 */ 424 struct i2c_timings { 425 u32 bus_freq_hz; 426 u32 scl_rise_ns; 427 u32 scl_fall_ns; 428 u32 scl_int_delay_ns; 429 u32 sda_fall_ns; 430 }; 431 432 /** 433 * struct i2c_bus_recovery_info - I2C bus recovery information 434 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 435 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery(). 436 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 437 * recovery. Used internally for generic GPIO recovery. 438 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used 439 * internally for generic GPIO recovery. 440 * @get_sda: This gets current value of SDA line. Optional for generic SCL 441 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO 442 * recovery. 443 * @prepare_recovery: This will be called before starting recovery. Platform may 444 * configure padmux here for SDA/SCL line or something else they want. 445 * @unprepare_recovery: This will be called after completing recovery. Platform 446 * may configure padmux here for SDA/SCL line or something else they want. 447 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery. 448 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery. 449 */ 450 struct i2c_bus_recovery_info { 451 int (*recover_bus)(struct i2c_adapter *); 452 453 int (*get_scl)(struct i2c_adapter *); 454 void (*set_scl)(struct i2c_adapter *, int val); 455 int (*get_sda)(struct i2c_adapter *); 456 457 void (*prepare_recovery)(struct i2c_adapter *); 458 void (*unprepare_recovery)(struct i2c_adapter *); 459 460 /* gpio recovery */ 461 int scl_gpio; 462 int sda_gpio; 463 }; 464 465 int i2c_recover_bus(struct i2c_adapter *adap); 466 467 /* Generic recovery routines */ 468 int i2c_generic_gpio_recovery(struct i2c_adapter *adap); 469 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 470 471 /** 472 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 473 * @flags: see I2C_AQ_* for possible flags and read below 474 * @max_num_msgs: maximum number of messages per transfer 475 * @max_write_len: maximum length of a write message 476 * @max_read_len: maximum length of a read message 477 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 478 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 479 * 480 * Note about combined messages: Some I2C controllers can only send one message 481 * per transfer, plus something called combined message or write-then-read. 482 * This is (usually) a small write message followed by a read message and 483 * barely enough to access register based devices like EEPROMs. There is a flag 484 * to support this mode. It implies max_num_msg = 2 and does the length checks 485 * with max_comb_*_len because combined message mode usually has its own 486 * limitations. Because of HW implementations, some controllers can actually do 487 * write-then-anything or other variants. To support that, write-then-read has 488 * been broken out into smaller bits like write-first and read-second which can 489 * be combined as needed. 490 */ 491 492 struct i2c_adapter_quirks { 493 u64 flags; 494 int max_num_msgs; 495 u16 max_write_len; 496 u16 max_read_len; 497 u16 max_comb_1st_msg_len; 498 u16 max_comb_2nd_msg_len; 499 }; 500 501 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 502 #define I2C_AQ_COMB BIT(0) 503 /* first combined message must be write */ 504 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 505 /* second combined message must be read */ 506 #define I2C_AQ_COMB_READ_SECOND BIT(2) 507 /* both combined messages must have the same target address */ 508 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 509 /* convenience macro for typical write-then read case */ 510 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 511 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 512 /* clock stretching is not supported */ 513 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 514 515 /* 516 * i2c_adapter is the structure used to identify a physical i2c bus along 517 * with the access algorithms necessary to access it. 518 */ 519 struct i2c_adapter { 520 struct module *owner; 521 unsigned int class; /* classes to allow probing for */ 522 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 523 void *algo_data; 524 525 /* data fields that are valid for all devices */ 526 struct rt_mutex bus_lock; 527 struct rt_mutex mux_lock; 528 529 int timeout; /* in jiffies */ 530 int retries; 531 struct device dev; /* the adapter device */ 532 533 int nr; 534 char name[48]; 535 struct completion dev_released; 536 537 struct mutex userspace_clients_lock; 538 struct list_head userspace_clients; 539 540 struct i2c_bus_recovery_info *bus_recovery_info; 541 const struct i2c_adapter_quirks *quirks; 542 543 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 544 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 545 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 546 }; 547 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 548 549 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 550 { 551 return dev_get_drvdata(&dev->dev); 552 } 553 554 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 555 { 556 dev_set_drvdata(&dev->dev, data); 557 } 558 559 static inline struct i2c_adapter * 560 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 561 { 562 #if IS_ENABLED(CONFIG_I2C_MUX) 563 struct device *parent = adapter->dev.parent; 564 565 if (parent != NULL && parent->type == &i2c_adapter_type) 566 return to_i2c_adapter(parent); 567 else 568 #endif 569 return NULL; 570 } 571 572 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 573 574 /* Adapter locking functions, exported for shared pin cases */ 575 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 576 #define I2C_LOCK_SEGMENT BIT(1) 577 578 /** 579 * i2c_lock_bus - Get exclusive access to an I2C bus segment 580 * @adapter: Target I2C bus segment 581 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 582 * locks only this branch in the adapter tree 583 */ 584 static inline void 585 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 586 { 587 adapter->lock_bus(adapter, flags); 588 } 589 590 /** 591 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 592 * @adapter: Target I2C bus segment 593 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 594 * unlocks only this branch in the adapter tree 595 */ 596 static inline void 597 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 598 { 599 adapter->unlock_bus(adapter, flags); 600 } 601 602 static inline void 603 i2c_lock_adapter(struct i2c_adapter *adapter) 604 { 605 i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 606 } 607 608 static inline void 609 i2c_unlock_adapter(struct i2c_adapter *adapter) 610 { 611 i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 612 } 613 614 /*flags for the client struct: */ 615 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 616 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 617 /* Must equal I2C_M_TEN below */ 618 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 619 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 620 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 621 /* Must match I2C_M_STOP|IGNORE_NAK */ 622 623 /* i2c adapter classes (bitmask) */ 624 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 625 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 626 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 627 #define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */ 628 629 /* Internal numbers to terminate lists */ 630 #define I2C_CLIENT_END 0xfffeU 631 632 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 633 #define I2C_ADDRS(addr, addrs...) \ 634 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 635 636 637 /* ----- functions exported by i2c.o */ 638 639 /* administration... 640 */ 641 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 642 extern int i2c_add_adapter(struct i2c_adapter *); 643 extern void i2c_del_adapter(struct i2c_adapter *); 644 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 645 646 extern int i2c_register_driver(struct module *, struct i2c_driver *); 647 extern void i2c_del_driver(struct i2c_driver *); 648 649 /* use a define to avoid include chaining to get THIS_MODULE */ 650 #define i2c_add_driver(driver) \ 651 i2c_register_driver(THIS_MODULE, driver) 652 653 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 654 extern void i2c_release_client(struct i2c_client *client); 655 656 /* call the i2c_client->command() of all attached clients with 657 * the given arguments */ 658 extern void i2c_clients_command(struct i2c_adapter *adap, 659 unsigned int cmd, void *arg); 660 661 extern struct i2c_adapter *i2c_get_adapter(int nr); 662 extern void i2c_put_adapter(struct i2c_adapter *adap); 663 664 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 665 666 /* Return the functionality mask */ 667 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 668 { 669 return adap->algo->functionality(adap); 670 } 671 672 /* Return 1 if adapter supports everything we need, 0 if not. */ 673 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 674 { 675 return (func & i2c_get_functionality(adap)) == func; 676 } 677 678 /** 679 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 680 * @adap: i2c adapter 681 * @quirks: quirk flags 682 * 683 * Return: true if the adapter has all the specified quirk flags, false if not 684 */ 685 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 686 { 687 if (!adap->quirks) 688 return false; 689 return (adap->quirks->flags & quirks) == quirks; 690 } 691 692 /* Return the adapter number for a specific adapter */ 693 static inline int i2c_adapter_id(struct i2c_adapter *adap) 694 { 695 return adap->nr; 696 } 697 698 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 699 { 700 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 701 } 702 703 /** 704 * module_i2c_driver() - Helper macro for registering a modular I2C driver 705 * @__i2c_driver: i2c_driver struct 706 * 707 * Helper macro for I2C drivers which do not do anything special in module 708 * init/exit. This eliminates a lot of boilerplate. Each module may only 709 * use this macro once, and calling it replaces module_init() and module_exit() 710 */ 711 #define module_i2c_driver(__i2c_driver) \ 712 module_driver(__i2c_driver, i2c_add_driver, \ 713 i2c_del_driver) 714 715 /** 716 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 717 * @__i2c_driver: i2c_driver struct 718 * 719 * Helper macro for I2C drivers which do not do anything special in their 720 * init. This eliminates a lot of boilerplate. Each driver may only 721 * use this macro once, and calling it replaces device_initcall(). 722 */ 723 #define builtin_i2c_driver(__i2c_driver) \ 724 builtin_driver(__i2c_driver, i2c_add_driver) 725 726 #endif /* I2C */ 727 728 #if IS_ENABLED(CONFIG_OF) 729 /* must call put_device() when done with returned i2c_client device */ 730 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 731 732 /* must call put_device() when done with returned i2c_adapter device */ 733 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 734 735 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 736 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 737 738 #else 739 740 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 741 { 742 return NULL; 743 } 744 745 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 746 { 747 return NULL; 748 } 749 750 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 751 { 752 return NULL; 753 } 754 #endif /* CONFIG_OF */ 755 756 #endif /* _LINUX_I2C_H */ 757