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/rtmutex.h> 34 #include <linux/irqdomain.h> /* for Host Notify IRQ */ 35 #include <linux/of.h> /* for struct device_node */ 36 #include <linux/swab.h> /* for swab16 */ 37 #include <uapi/linux/i2c.h> 38 39 extern struct bus_type i2c_bus_type; 40 extern struct device_type i2c_adapter_type; 41 extern struct device_type i2c_client_type; 42 43 /* --- General options ------------------------------------------------ */ 44 45 struct i2c_msg; 46 struct i2c_algorithm; 47 struct i2c_adapter; 48 struct i2c_client; 49 struct i2c_driver; 50 union i2c_smbus_data; 51 struct i2c_board_info; 52 enum i2c_slave_event; 53 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 54 55 struct module; 56 struct property_entry; 57 58 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 59 /* 60 * The master routines are the ones normally used to transmit data to devices 61 * on a bus (or read from them). Apart from two basic transfer functions to 62 * transmit one message at a time, a more complex version can be used to 63 * transmit an arbitrary number of messages without interruption. 64 * @count must be be less than 64k since msg.len is u16. 65 */ 66 extern int i2c_master_send(const struct i2c_client *client, const char *buf, 67 int count); 68 extern int i2c_master_recv(const struct i2c_client *client, char *buf, 69 int count); 70 71 /* Transfer num messages. 72 */ 73 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 74 int num); 75 /* Unlocked flavor */ 76 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 77 int num); 78 79 /* This is the very generalized SMBus access routine. You probably do not 80 want to use this, though; one of the functions below may be much easier, 81 and probably just as fast. 82 Note that we use i2c_adapter here, because you do not need a specific 83 smbus adapter to call this function. */ 84 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 85 unsigned short flags, char read_write, u8 command, 86 int size, union i2c_smbus_data *data); 87 88 /* Now follow the 'nice' access routines. These also document the calling 89 conventions of i2c_smbus_xfer. */ 90 91 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 92 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 93 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 94 u8 command); 95 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 96 u8 command, u8 value); 97 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 98 u8 command); 99 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 100 u8 command, u16 value); 101 102 static inline s32 103 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 104 { 105 s32 value = i2c_smbus_read_word_data(client, command); 106 107 return (value < 0) ? value : swab16(value); 108 } 109 110 static inline s32 111 i2c_smbus_write_word_swapped(const struct i2c_client *client, 112 u8 command, u16 value) 113 { 114 return i2c_smbus_write_word_data(client, command, swab16(value)); 115 } 116 117 /* Returns the number of read bytes */ 118 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 119 u8 command, u8 *values); 120 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 121 u8 command, u8 length, const u8 *values); 122 /* Returns the number of read bytes */ 123 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 124 u8 command, u8 length, u8 *values); 125 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 126 u8 command, u8 length, 127 const u8 *values); 128 extern s32 129 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 130 u8 command, u8 length, u8 *values); 131 #endif /* I2C */ 132 133 enum i2c_alert_protocol { 134 I2C_PROTOCOL_SMBUS_ALERT, 135 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 136 }; 137 138 /** 139 * struct i2c_driver - represent an I2C device driver 140 * @class: What kind of i2c device we instantiate (for detect) 141 * @attach_adapter: Callback for bus addition (deprecated) 142 * @probe: Callback for device binding - soon to be deprecated 143 * @probe_new: New callback for device binding 144 * @remove: Callback for device unbinding 145 * @shutdown: Callback for device shutdown 146 * @alert: Alert callback, for example for the SMBus alert protocol 147 * @command: Callback for bus-wide signaling (optional) 148 * @driver: Device driver model driver 149 * @id_table: List of I2C devices supported by this driver 150 * @detect: Callback for device detection 151 * @address_list: The I2C addresses to probe (for detect) 152 * @clients: List of detected clients we created (for i2c-core use only) 153 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 154 * 155 * The driver.owner field should be set to the module owner of this driver. 156 * The driver.name field should be set to the name of this driver. 157 * 158 * For automatic device detection, both @detect and @address_list must 159 * be defined. @class should also be set, otherwise only devices forced 160 * with module parameters will be created. The detect function must 161 * fill at least the name field of the i2c_board_info structure it is 162 * handed upon successful detection, and possibly also the flags field. 163 * 164 * If @detect is missing, the driver will still work fine for enumerated 165 * devices. Detected devices simply won't be supported. This is expected 166 * for the many I2C/SMBus devices which can't be detected reliably, and 167 * the ones which can always be enumerated in practice. 168 * 169 * The i2c_client structure which is handed to the @detect callback is 170 * not a real i2c_client. It is initialized just enough so that you can 171 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 172 * else with it. In particular, calling dev_dbg and friends on it is 173 * not allowed. 174 */ 175 struct i2c_driver { 176 unsigned int class; 177 178 /* Notifies the driver that a new bus has appeared. You should avoid 179 * using this, it will be removed in a near future. 180 */ 181 int (*attach_adapter)(struct i2c_adapter *) __deprecated; 182 183 /* Standard driver model interfaces */ 184 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 185 int (*remove)(struct i2c_client *); 186 187 /* New driver model interface to aid the seamless removal of the 188 * current probe()'s, more commonly unused than used second parameter. 189 */ 190 int (*probe_new)(struct i2c_client *); 191 192 /* driver model interfaces that don't relate to enumeration */ 193 void (*shutdown)(struct i2c_client *); 194 195 /* Alert callback, for example for the SMBus alert protocol. 196 * The format and meaning of the data value depends on the protocol. 197 * For the SMBus alert protocol, there is a single bit of data passed 198 * as the alert response's low bit ("event flag"). 199 * For the SMBus Host Notify protocol, the data corresponds to the 200 * 16-bit payload data reported by the slave device acting as master. 201 */ 202 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, 203 unsigned int data); 204 205 /* a ioctl like command that can be used to perform specific functions 206 * with the device. 207 */ 208 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 209 210 struct device_driver driver; 211 const struct i2c_device_id *id_table; 212 213 /* Device detection callback for automatic device creation */ 214 int (*detect)(struct i2c_client *, struct i2c_board_info *); 215 const unsigned short *address_list; 216 struct list_head clients; 217 218 bool disable_i2c_core_irq_mapping; 219 }; 220 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 221 222 /** 223 * struct i2c_client - represent an I2C slave device 224 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 225 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 226 * @addr: Address used on the I2C bus connected to the parent adapter. 227 * @name: Indicates the type of the device, usually a chip name that's 228 * generic enough to hide second-sourcing and compatible revisions. 229 * @adapter: manages the bus segment hosting this I2C device 230 * @dev: Driver model device node for the slave. 231 * @irq: indicates the IRQ generated by this device (if any) 232 * @detected: member of an i2c_driver.clients list or i2c-core's 233 * userspace_devices list 234 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 235 * calls it to pass on slave events to the slave driver. 236 * 237 * An i2c_client identifies a single device (i.e. chip) connected to an 238 * i2c bus. The behaviour exposed to Linux is defined by the driver 239 * managing the device. 240 */ 241 struct i2c_client { 242 unsigned short flags; /* div., see below */ 243 unsigned short addr; /* chip address - NOTE: 7bit */ 244 /* addresses are stored in the */ 245 /* _LOWER_ 7 bits */ 246 char name[I2C_NAME_SIZE]; 247 struct i2c_adapter *adapter; /* the adapter we sit on */ 248 struct device dev; /* the device structure */ 249 int irq; /* irq issued by device */ 250 struct list_head detected; 251 #if IS_ENABLED(CONFIG_I2C_SLAVE) 252 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 253 #endif 254 }; 255 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 256 257 extern struct i2c_client *i2c_verify_client(struct device *dev); 258 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 259 extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 260 const struct i2c_client *client); 261 262 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 263 { 264 struct device * const dev = container_of(kobj, struct device, kobj); 265 return to_i2c_client(dev); 266 } 267 268 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 269 { 270 return dev_get_drvdata(&dev->dev); 271 } 272 273 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 274 { 275 dev_set_drvdata(&dev->dev, data); 276 } 277 278 /* I2C slave support */ 279 280 #if IS_ENABLED(CONFIG_I2C_SLAVE) 281 enum i2c_slave_event { 282 I2C_SLAVE_READ_REQUESTED, 283 I2C_SLAVE_WRITE_REQUESTED, 284 I2C_SLAVE_READ_PROCESSED, 285 I2C_SLAVE_WRITE_RECEIVED, 286 I2C_SLAVE_STOP, 287 }; 288 289 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 290 extern int i2c_slave_unregister(struct i2c_client *client); 291 extern bool i2c_detect_slave_mode(struct device *dev); 292 293 static inline int i2c_slave_event(struct i2c_client *client, 294 enum i2c_slave_event event, u8 *val) 295 { 296 return client->slave_cb(client, event, val); 297 } 298 #else 299 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 300 #endif 301 302 /** 303 * struct i2c_board_info - template for device creation 304 * @type: chip type, to initialize i2c_client.name 305 * @flags: to initialize i2c_client.flags 306 * @addr: stored in i2c_client.addr 307 * @platform_data: stored in i2c_client.dev.platform_data 308 * @archdata: copied into i2c_client.dev.archdata 309 * @of_node: pointer to OpenFirmware device node 310 * @fwnode: device node supplied by the platform firmware 311 * @properties: additional device properties for the device 312 * @resources: resources associated with the device 313 * @num_resources: number of resources in the @resources array 314 * @irq: stored in i2c_client.irq 315 * 316 * I2C doesn't actually support hardware probing, although controllers and 317 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 318 * a device at a given address. Drivers commonly need more information than 319 * that, such as chip type, configuration, associated IRQ, and so on. 320 * 321 * i2c_board_info is used to build tables of information listing I2C devices 322 * that are present. This information is used to grow the driver model tree. 323 * For mainboards this is done statically using i2c_register_board_info(); 324 * bus numbers identify adapters that aren't yet available. For add-on boards, 325 * i2c_new_device() does this dynamically with the adapter already known. 326 */ 327 struct i2c_board_info { 328 char type[I2C_NAME_SIZE]; 329 unsigned short flags; 330 unsigned short addr; 331 void *platform_data; 332 struct dev_archdata *archdata; 333 struct device_node *of_node; 334 struct fwnode_handle *fwnode; 335 const struct property_entry *properties; 336 const struct resource *resources; 337 unsigned int num_resources; 338 int irq; 339 }; 340 341 /** 342 * I2C_BOARD_INFO - macro used to list an i2c device and its address 343 * @dev_type: identifies the device type 344 * @dev_addr: the device's address on the bus. 345 * 346 * This macro initializes essential fields of a struct i2c_board_info, 347 * declaring what has been provided on a particular board. Optional 348 * fields (such as associated irq, or device-specific platform_data) 349 * are provided using conventional syntax. 350 */ 351 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 352 .type = dev_type, .addr = (dev_addr) 353 354 355 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 356 /* Add-on boards should register/unregister their devices; e.g. a board 357 * with integrated I2C, a config eeprom, sensors, and a codec that's 358 * used in conjunction with the primary hardware. 359 */ 360 extern struct i2c_client * 361 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 362 363 /* If you don't know the exact address of an I2C device, use this variant 364 * instead, which can probe for device presence in a list of possible 365 * addresses. The "probe" callback function is optional. If it is provided, 366 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 367 * a default probing method is used. 368 */ 369 extern struct i2c_client * 370 i2c_new_probed_device(struct i2c_adapter *adap, 371 struct i2c_board_info *info, 372 unsigned short const *addr_list, 373 int (*probe)(struct i2c_adapter *, unsigned short addr)); 374 375 /* Common custom probe functions */ 376 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 377 378 /* For devices that use several addresses, use i2c_new_dummy() to make 379 * client handles for the extra addresses. 380 */ 381 extern struct i2c_client * 382 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 383 384 extern struct i2c_client * 385 i2c_new_secondary_device(struct i2c_client *client, 386 const char *name, 387 u16 default_addr); 388 389 extern void i2c_unregister_device(struct i2c_client *); 390 #endif /* I2C */ 391 392 /* Mainboard arch_initcall() code should register all its I2C devices. 393 * This is done at arch_initcall time, before declaring any i2c adapters. 394 * Modules for add-on boards must use other calls. 395 */ 396 #ifdef CONFIG_I2C_BOARDINFO 397 extern int 398 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 399 unsigned n); 400 #else 401 static inline int 402 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 403 unsigned n) 404 { 405 return 0; 406 } 407 #endif /* I2C_BOARDINFO */ 408 409 /** 410 * struct i2c_algorithm - represent I2C transfer method 411 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 412 * defined by the msgs array, with num messages available to transfer via 413 * the adapter specified by adap. 414 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 415 * is not present, then the bus layer will try and convert the SMBus calls 416 * into I2C transfers instead. 417 * @functionality: Return the flags that this algorithm/adapter pair supports 418 * from the I2C_FUNC_* flags. 419 * @reg_slave: Register given client to I2C slave mode of this adapter 420 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 421 * 422 * The following structs are for those who like to implement new bus drivers: 423 * i2c_algorithm is the interface to a class of hardware solutions which can 424 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 425 * to name two of the most common. 426 * 427 * The return codes from the @master_xfer field should indicate the type of 428 * error code that occurred during the transfer, as documented in the kernel 429 * Documentation file Documentation/i2c/fault-codes. 430 */ 431 struct i2c_algorithm { 432 /* If an adapter algorithm can't do I2C-level access, set master_xfer 433 to NULL. If an adapter algorithm can do SMBus access, set 434 smbus_xfer. If set to NULL, the SMBus protocol is simulated 435 using common I2C messages */ 436 /* master_xfer should return the number of messages successfully 437 processed, or a negative value on error */ 438 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 439 int num); 440 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 441 unsigned short flags, char read_write, 442 u8 command, int size, union i2c_smbus_data *data); 443 444 /* To determine what the adapter supports */ 445 u32 (*functionality) (struct i2c_adapter *); 446 447 #if IS_ENABLED(CONFIG_I2C_SLAVE) 448 int (*reg_slave)(struct i2c_client *client); 449 int (*unreg_slave)(struct i2c_client *client); 450 #endif 451 }; 452 453 /** 454 * struct i2c_lock_operations - represent I2C locking operations 455 * @lock_bus: Get exclusive access to an I2C bus segment 456 * @trylock_bus: Try to get exclusive access to an I2C bus segment 457 * @unlock_bus: Release exclusive access to an I2C bus segment 458 * 459 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 460 */ 461 struct i2c_lock_operations { 462 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 463 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 464 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 465 }; 466 467 /** 468 * struct i2c_timings - I2C timing information 469 * @bus_freq_hz: the bus frequency in Hz 470 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 471 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 472 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 473 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 474 */ 475 struct i2c_timings { 476 u32 bus_freq_hz; 477 u32 scl_rise_ns; 478 u32 scl_fall_ns; 479 u32 scl_int_delay_ns; 480 u32 sda_fall_ns; 481 }; 482 483 /** 484 * struct i2c_bus_recovery_info - I2C bus recovery information 485 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 486 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery(). 487 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 488 * recovery. Used internally for generic GPIO recovery. 489 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used 490 * internally for generic GPIO recovery. 491 * @get_sda: This gets current value of SDA line. Optional for generic SCL 492 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO 493 * recovery. 494 * @prepare_recovery: This will be called before starting recovery. Platform may 495 * configure padmux here for SDA/SCL line or something else they want. 496 * @unprepare_recovery: This will be called after completing recovery. Platform 497 * may configure padmux here for SDA/SCL line or something else they want. 498 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery. 499 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery. 500 */ 501 struct i2c_bus_recovery_info { 502 int (*recover_bus)(struct i2c_adapter *); 503 504 int (*get_scl)(struct i2c_adapter *); 505 void (*set_scl)(struct i2c_adapter *, int val); 506 int (*get_sda)(struct i2c_adapter *); 507 508 void (*prepare_recovery)(struct i2c_adapter *); 509 void (*unprepare_recovery)(struct i2c_adapter *); 510 511 /* gpio recovery */ 512 int scl_gpio; 513 int sda_gpio; 514 }; 515 516 int i2c_recover_bus(struct i2c_adapter *adap); 517 518 /* Generic recovery routines */ 519 int i2c_generic_gpio_recovery(struct i2c_adapter *adap); 520 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 521 522 /** 523 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 524 * @flags: see I2C_AQ_* for possible flags and read below 525 * @max_num_msgs: maximum number of messages per transfer 526 * @max_write_len: maximum length of a write message 527 * @max_read_len: maximum length of a read message 528 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 529 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 530 * 531 * Note about combined messages: Some I2C controllers can only send one message 532 * per transfer, plus something called combined message or write-then-read. 533 * This is (usually) a small write message followed by a read message and 534 * barely enough to access register based devices like EEPROMs. There is a flag 535 * to support this mode. It implies max_num_msg = 2 and does the length checks 536 * with max_comb_*_len because combined message mode usually has its own 537 * limitations. Because of HW implementations, some controllers can actually do 538 * write-then-anything or other variants. To support that, write-then-read has 539 * been broken out into smaller bits like write-first and read-second which can 540 * be combined as needed. 541 */ 542 543 struct i2c_adapter_quirks { 544 u64 flags; 545 int max_num_msgs; 546 u16 max_write_len; 547 u16 max_read_len; 548 u16 max_comb_1st_msg_len; 549 u16 max_comb_2nd_msg_len; 550 }; 551 552 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 553 #define I2C_AQ_COMB BIT(0) 554 /* first combined message must be write */ 555 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 556 /* second combined message must be read */ 557 #define I2C_AQ_COMB_READ_SECOND BIT(2) 558 /* both combined messages must have the same target address */ 559 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 560 /* convenience macro for typical write-then read case */ 561 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 562 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 563 /* clock stretching is not supported */ 564 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 565 566 /* 567 * i2c_adapter is the structure used to identify a physical i2c bus along 568 * with the access algorithms necessary to access it. 569 */ 570 struct i2c_adapter { 571 struct module *owner; 572 unsigned int class; /* classes to allow probing for */ 573 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 574 void *algo_data; 575 576 /* data fields that are valid for all devices */ 577 const struct i2c_lock_operations *lock_ops; 578 struct rt_mutex bus_lock; 579 struct rt_mutex mux_lock; 580 581 int timeout; /* in jiffies */ 582 int retries; 583 struct device dev; /* the adapter device */ 584 585 int nr; 586 char name[48]; 587 struct completion dev_released; 588 589 struct mutex userspace_clients_lock; 590 struct list_head userspace_clients; 591 592 struct i2c_bus_recovery_info *bus_recovery_info; 593 const struct i2c_adapter_quirks *quirks; 594 595 struct irq_domain *host_notify_domain; 596 }; 597 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 598 599 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 600 { 601 return dev_get_drvdata(&dev->dev); 602 } 603 604 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 605 { 606 dev_set_drvdata(&dev->dev, data); 607 } 608 609 static inline struct i2c_adapter * 610 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 611 { 612 #if IS_ENABLED(CONFIG_I2C_MUX) 613 struct device *parent = adapter->dev.parent; 614 615 if (parent != NULL && parent->type == &i2c_adapter_type) 616 return to_i2c_adapter(parent); 617 else 618 #endif 619 return NULL; 620 } 621 622 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 623 624 /* Adapter locking functions, exported for shared pin cases */ 625 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 626 #define I2C_LOCK_SEGMENT BIT(1) 627 628 /** 629 * i2c_lock_bus - Get exclusive access to an I2C bus segment 630 * @adapter: Target I2C bus segment 631 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 632 * locks only this branch in the adapter tree 633 */ 634 static inline void 635 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 636 { 637 adapter->lock_ops->lock_bus(adapter, flags); 638 } 639 640 /** 641 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 642 * @adapter: Target I2C bus segment 643 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 644 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 645 * 646 * Return: true if the I2C bus segment is locked, false otherwise 647 */ 648 static inline int 649 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 650 { 651 return adapter->lock_ops->trylock_bus(adapter, flags); 652 } 653 654 /** 655 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 656 * @adapter: Target I2C bus segment 657 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 658 * unlocks only this branch in the adapter tree 659 */ 660 static inline void 661 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 662 { 663 adapter->lock_ops->unlock_bus(adapter, flags); 664 } 665 666 static inline void 667 i2c_lock_adapter(struct i2c_adapter *adapter) 668 { 669 i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 670 } 671 672 static inline void 673 i2c_unlock_adapter(struct i2c_adapter *adapter) 674 { 675 i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 676 } 677 678 /*flags for the client struct: */ 679 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 680 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 681 /* Must equal I2C_M_TEN below */ 682 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 683 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 684 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 685 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 686 /* Must match I2C_M_STOP|IGNORE_NAK */ 687 688 /* i2c adapter classes (bitmask) */ 689 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 690 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 691 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 692 #define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */ 693 694 /* Internal numbers to terminate lists */ 695 #define I2C_CLIENT_END 0xfffeU 696 697 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 698 #define I2C_ADDRS(addr, addrs...) \ 699 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 700 701 702 /* ----- functions exported by i2c.o */ 703 704 /* administration... 705 */ 706 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 707 extern int i2c_add_adapter(struct i2c_adapter *); 708 extern void i2c_del_adapter(struct i2c_adapter *); 709 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 710 711 extern int i2c_register_driver(struct module *, struct i2c_driver *); 712 extern void i2c_del_driver(struct i2c_driver *); 713 714 /* use a define to avoid include chaining to get THIS_MODULE */ 715 #define i2c_add_driver(driver) \ 716 i2c_register_driver(THIS_MODULE, driver) 717 718 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 719 extern void i2c_release_client(struct i2c_client *client); 720 721 /* call the i2c_client->command() of all attached clients with 722 * the given arguments */ 723 extern void i2c_clients_command(struct i2c_adapter *adap, 724 unsigned int cmd, void *arg); 725 726 extern struct i2c_adapter *i2c_get_adapter(int nr); 727 extern void i2c_put_adapter(struct i2c_adapter *adap); 728 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 729 730 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 731 732 /* Return the functionality mask */ 733 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 734 { 735 return adap->algo->functionality(adap); 736 } 737 738 /* Return 1 if adapter supports everything we need, 0 if not. */ 739 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 740 { 741 return (func & i2c_get_functionality(adap)) == func; 742 } 743 744 /** 745 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 746 * @adap: i2c adapter 747 * @quirks: quirk flags 748 * 749 * Return: true if the adapter has all the specified quirk flags, false if not 750 */ 751 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 752 { 753 if (!adap->quirks) 754 return false; 755 return (adap->quirks->flags & quirks) == quirks; 756 } 757 758 /* Return the adapter number for a specific adapter */ 759 static inline int i2c_adapter_id(struct i2c_adapter *adap) 760 { 761 return adap->nr; 762 } 763 764 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 765 { 766 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 767 } 768 769 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 770 /** 771 * module_i2c_driver() - Helper macro for registering a modular I2C driver 772 * @__i2c_driver: i2c_driver struct 773 * 774 * Helper macro for I2C drivers which do not do anything special in module 775 * init/exit. This eliminates a lot of boilerplate. Each module may only 776 * use this macro once, and calling it replaces module_init() and module_exit() 777 */ 778 #define module_i2c_driver(__i2c_driver) \ 779 module_driver(__i2c_driver, i2c_add_driver, \ 780 i2c_del_driver) 781 782 /** 783 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 784 * @__i2c_driver: i2c_driver struct 785 * 786 * Helper macro for I2C drivers which do not do anything special in their 787 * init. This eliminates a lot of boilerplate. Each driver may only 788 * use this macro once, and calling it replaces device_initcall(). 789 */ 790 #define builtin_i2c_driver(__i2c_driver) \ 791 builtin_driver(__i2c_driver, i2c_add_driver) 792 793 #endif /* I2C */ 794 795 #if IS_ENABLED(CONFIG_OF) 796 /* must call put_device() when done with returned i2c_client device */ 797 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 798 799 /* must call put_device() when done with returned i2c_adapter device */ 800 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 801 802 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 803 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 804 805 extern const struct of_device_id 806 *i2c_of_match_device(const struct of_device_id *matches, 807 struct i2c_client *client); 808 809 #else 810 811 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 812 { 813 return NULL; 814 } 815 816 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 817 { 818 return NULL; 819 } 820 821 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 822 { 823 return NULL; 824 } 825 826 static inline const struct of_device_id 827 *i2c_of_match_device(const struct of_device_id *matches, 828 struct i2c_client *client) 829 { 830 return NULL; 831 } 832 833 #endif /* CONFIG_OF */ 834 835 #if IS_ENABLED(CONFIG_ACPI) 836 u32 i2c_acpi_find_bus_speed(struct device *dev); 837 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 838 struct i2c_board_info *info); 839 #else 840 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 841 { 842 return 0; 843 } 844 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 845 int index, struct i2c_board_info *info) 846 { 847 return NULL; 848 } 849 #endif /* CONFIG_ACPI */ 850 851 #endif /* _LINUX_I2C_H */ 852