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