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i2c.h
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linux-6.19.14/include/linux/i2c.h
1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * i2c.h - definitions for the Linux i2c bus interface 4 * Copyright (C) 1995-2000 Simon G. Vogl 5 * Copyright (C) 2013-2019 Wolfram Sang <wsa@kernel.org> 6 * 7 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and 8 * Frodo Looijaard <frodol@dds.nl> 9 */ 10#ifndef _LINUX_I2C_H 11#define _LINUX_I2C_H 12 13#include <linux/acpi.h> /* for acpi_handle */ 14#include <linux/bits.h> 15#include <linux/mod_devicetable.h> 16#include <linux/device.h> /* for struct device */ 17#include <linux/sched.h> /* for completion */ 18#include <linux/mutex.h> 19#include <linux/regulator/consumer.h> 20#include <linux/rtmutex.h> 21#include <linux/irqdomain.h> /* for Host Notify IRQ */ 22#include <linux/of.h> /* for struct device_node */ 23#include <linux/swab.h> /* for swab16 */ 24#include <uapi/linux/i2c.h> 25 26extern const struct bus_type i2c_bus_type; 27extern const struct device_type i2c_adapter_type; 28extern const struct device_type i2c_client_type; 29 30/* --- General options ------------------------------------------------ */ 31 32struct i2c_msg; 33struct i2c_adapter; 34struct i2c_client; 35struct i2c_driver; 36struct i2c_device_identity; 37union i2c_smbus_data; 38struct i2c_board_info; 39enum i2c_slave_event; 40typedef int (*i2c_slave_cb_t)(struct i2c_client *client, 41 enum i2c_slave_event event, u8 *val); 42 43/* I2C Frequency Modes */ 44#define I2C_MAX_STANDARD_MODE_FREQ 100000 45#define I2C_MAX_FAST_MODE_FREQ 400000 46#define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000 47#define I2C_MAX_TURBO_MODE_FREQ 1400000 48#define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000 49#define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000 50 51struct module; 52struct property_entry; 53 54#if IS_ENABLED(CONFIG_I2C) 55/* Return the Frequency mode string based on the bus frequency */ 56const char *i2c_freq_mode_string(u32 bus_freq_hz); 57 58/* 59 * The master routines are the ones normally used to transmit data to devices 60 * on a bus (or read from them). Apart from two basic transfer functions to 61 * transmit one message at a time, a more complex version can be used to 62 * transmit an arbitrary number of messages without interruption. 63 * @count must be less than 64k since msg.len is u16. 64 */ 65int i2c_transfer_buffer_flags(const struct i2c_client *client, 66 char *buf, int count, u16 flags); 67 68/** 69 * i2c_master_recv - issue a single I2C message in master receive mode 70 * @client: Handle to slave device 71 * @buf: Where to store data read from slave 72 * @count: How many bytes to read, must be less than 64k since msg.len is u16 73 * 74 * Returns negative errno, or else the number of bytes read. 75 */ 76static inline int i2c_master_recv(const struct i2c_client *client, 77 char *buf, int count) 78{ 79 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 80}; 81 82/** 83 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 84 * using a DMA safe buffer 85 * @client: Handle to slave device 86 * @buf: Where to store data read from slave, must be safe to use with DMA 87 * @count: How many bytes to read, must be less than 64k since msg.len is u16 88 * 89 * Returns negative errno, or else the number of bytes read. 90 */ 91static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 92 char *buf, int count) 93{ 94 return i2c_transfer_buffer_flags(client, buf, count, 95 I2C_M_RD | I2C_M_DMA_SAFE); 96}; 97 98/** 99 * i2c_master_send - issue a single I2C message in master transmit mode 100 * @client: Handle to slave device 101 * @buf: Data that will be written to the slave 102 * @count: How many bytes to write, must be less than 64k since msg.len is u16 103 * 104 * Returns negative errno, or else the number of bytes written. 105 */ 106static inline int i2c_master_send(const struct i2c_client *client, 107 const char *buf, int count) 108{ 109 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 110}; 111 112/** 113 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 114 * using a DMA safe buffer 115 * @client: Handle to slave device 116 * @buf: Data that will be written to the slave, must be safe to use with DMA 117 * @count: How many bytes to write, must be less than 64k since msg.len is u16 118 * 119 * Returns negative errno, or else the number of bytes written. 120 */ 121static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 122 const char *buf, int count) 123{ 124 return i2c_transfer_buffer_flags(client, (char *)buf, count, 125 I2C_M_DMA_SAFE); 126}; 127 128/* Transfer num messages. 129 */ 130int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 131/* Unlocked flavor */ 132int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 133 134/* This is the very generalized SMBus access routine. You probably do not 135 want to use this, though; one of the functions below may be much easier, 136 and probably just as fast. 137 Note that we use i2c_adapter here, because you do not need a specific 138 smbus adapter to call this function. */ 139s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 140 unsigned short flags, char read_write, u8 command, 141 int protocol, union i2c_smbus_data *data); 142 143/* Unlocked flavor */ 144s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 145 unsigned short flags, char read_write, u8 command, 146 int protocol, union i2c_smbus_data *data); 147 148/* Now follow the 'nice' access routines. These also document the calling 149 conventions of i2c_smbus_xfer. */ 150 151u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count); 152s32 i2c_smbus_read_byte(const struct i2c_client *client); 153s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 154s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 155s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 156 u8 command, u8 value); 157s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 158s32 i2c_smbus_write_word_data(const struct i2c_client *client, 159 u8 command, u16 value); 160 161static inline s32 162i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 163{ 164 s32 value = i2c_smbus_read_word_data(client, command); 165 166 return (value < 0) ? value : swab16(value); 167} 168 169static inline s32 170i2c_smbus_write_word_swapped(const struct i2c_client *client, 171 u8 command, u16 value) 172{ 173 return i2c_smbus_write_word_data(client, command, swab16(value)); 174} 175 176/* Returns the number of read bytes */ 177s32 i2c_smbus_read_block_data(const struct i2c_client *client, 178 u8 command, u8 *values); 179s32 i2c_smbus_write_block_data(const struct i2c_client *client, 180 u8 command, u8 length, const u8 *values); 181/* Returns the number of read bytes */ 182s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 183 u8 command, u8 length, u8 *values); 184s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 185 u8 command, u8 length, const u8 *values); 186s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 187 u8 command, u8 length, 188 u8 *values); 189int i2c_get_device_id(const struct i2c_client *client, 190 struct i2c_device_identity *id); 191const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client); 192#endif /* I2C */ 193 194/** 195 * struct i2c_device_identity - i2c client device identification 196 * @manufacturer_id: 0 - 4095, database maintained by NXP 197 * @part_id: 0 - 511, according to manufacturer 198 * @die_revision: 0 - 7, according to manufacturer 199 */ 200struct i2c_device_identity { 201 u16 manufacturer_id; 202#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 203#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 204#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 205#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 206#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 207#define I2C_DEVICE_ID_ANALOG_DEVICES 5 208#define I2C_DEVICE_ID_STMICROELECTRONICS 6 209#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 210#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 211#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 212#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 213#define I2C_DEVICE_ID_FLIR 11 214#define I2C_DEVICE_ID_O2MICRO 12 215#define I2C_DEVICE_ID_ATMEL 13 216#define I2C_DEVICE_ID_NONE 0xffff 217 u16 part_id; 218 u8 die_revision; 219}; 220 221enum i2c_alert_protocol { 222 I2C_PROTOCOL_SMBUS_ALERT, 223 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 224}; 225 226/** 227 * enum i2c_driver_flags - Flags for an I2C device driver 228 * 229 * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe 230 */ 231enum i2c_driver_flags { 232 I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0), 233}; 234 235/** 236 * struct i2c_driver - represent an I2C device driver 237 * @class: What kind of i2c device we instantiate (for detect) 238 * @probe: Callback for device binding 239 * @remove: Callback for device unbinding 240 * @shutdown: Callback for device shutdown 241 * @alert: Alert callback, for example for the SMBus alert protocol 242 * @command: Callback for bus-wide signaling (optional) 243 * @driver: Device driver model driver 244 * @id_table: List of I2C devices supported by this driver 245 * @detect: Callback for device detection 246 * @address_list: The I2C addresses to probe (for detect) 247 * @clients: List of detected clients we created (for i2c-core use only) 248 * @flags: A bitmask of flags defined in &enum i2c_driver_flags 249 * 250 * The driver.owner field should be set to the module owner of this driver. 251 * The driver.name field should be set to the name of this driver. 252 * 253 * For automatic device detection, both @detect and @address_list must 254 * be defined. @class should also be set, otherwise only devices forced 255 * with module parameters will be created. The detect function must 256 * fill at least the name field of the i2c_board_info structure it is 257 * handed upon successful detection, and possibly also the flags field. 258 * 259 * If @detect is missing, the driver will still work fine for enumerated 260 * devices. Detected devices simply won't be supported. This is expected 261 * for the many I2C/SMBus devices which can't be detected reliably, and 262 * the ones which can always be enumerated in practice. 263 * 264 * The i2c_client structure which is handed to the @detect callback is 265 * not a real i2c_client. It is initialized just enough so that you can 266 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 267 * else with it. In particular, calling dev_dbg and friends on it is 268 * not allowed. 269 */ 270struct i2c_driver { 271 unsigned int class; 272 273 /* Standard driver model interfaces */ 274 int (*probe)(struct i2c_client *client); 275 void (*remove)(struct i2c_client *client); 276 277 278 /* driver model interfaces that don't relate to enumeration */ 279 void (*shutdown)(struct i2c_client *client); 280 281 /* Alert callback, for example for the SMBus alert protocol. 282 * The format and meaning of the data value depends on the protocol. 283 * For the SMBus alert protocol, there is a single bit of data passed 284 * as the alert response's low bit ("event flag"). 285 * For the SMBus Host Notify protocol, the data corresponds to the 286 * 16-bit payload data reported by the slave device acting as master. 287 */ 288 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 289 unsigned int data); 290 291 /* a ioctl like command that can be used to perform specific functions 292 * with the device. 293 */ 294 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 295 296 struct device_driver driver; 297 const struct i2c_device_id *id_table; 298 299 /* Device detection callback for automatic device creation */ 300 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 301 const unsigned short *address_list; 302 struct list_head clients; 303 304 u32 flags; 305}; 306#define to_i2c_driver(d) container_of_const(d, struct i2c_driver, driver) 307 308/** 309 * struct i2c_client - represent an I2C slave device 310 * @flags: see I2C_CLIENT_* for possible flags 311 * @addr: Address used on the I2C bus connected to the parent adapter. 312 * @name: Indicates the type of the device, usually a chip name that's 313 * generic enough to hide second-sourcing and compatible revisions. 314 * @adapter: manages the bus segment hosting this I2C device 315 * @dev: Driver model device node for the slave. 316 * @init_irq: IRQ that was set at initialization 317 * @irq: indicates the IRQ generated by this device (if any) 318 * @detected: member of an i2c_driver.clients list or i2c-core's 319 * userspace_devices list 320 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 321 * calls it to pass on slave events to the slave driver. 322 * @devres_group_id: id of the devres group that will be created for resources 323 * acquired when probing this device. 324 * @debugfs: pointer to the debugfs subdirectory which the I2C core created 325 * for this client. 326 * 327 * An i2c_client identifies a single device (i.e. chip) connected to an 328 * i2c bus. The behaviour exposed to Linux is defined by the driver 329 * managing the device. 330 */ 331struct i2c_client { 332 unsigned short flags; /* div., see below */ 333#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 334#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 335 /* Must equal I2C_M_TEN below */ 336#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 337#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 338#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 339#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 340 /* Must match I2C_M_STOP|IGNORE_NAK */ 341 342 unsigned short addr; /* chip address - NOTE: 7bit */ 343 /* addresses are stored in the */ 344 /* _LOWER_ 7 bits */ 345 char name[I2C_NAME_SIZE]; 346 struct i2c_adapter *adapter; /* the adapter we sit on */ 347 struct device dev; /* the device structure */ 348 int init_irq; /* irq set at initialization */ 349 int irq; /* irq issued by device */ 350 struct list_head detected; 351#if IS_ENABLED(CONFIG_I2C_SLAVE) 352 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 353#endif 354 void *devres_group_id; /* ID of probe devres group */ 355 struct dentry *debugfs; /* per-client debugfs dir */ 356}; 357#define to_i2c_client(d) container_of(d, struct i2c_client, dev) 358 359struct i2c_adapter *i2c_verify_adapter(struct device *dev); 360const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 361 const struct i2c_client *client); 362 363const void *i2c_get_match_data(const struct i2c_client *client); 364 365static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 366{ 367 struct device * const dev = kobj_to_dev(kobj); 368 return to_i2c_client(dev); 369} 370 371static inline void *i2c_get_clientdata(const struct i2c_client *client) 372{ 373 return dev_get_drvdata(&client->dev); 374} 375 376static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 377{ 378 dev_set_drvdata(&client->dev, data); 379} 380 381/* I2C slave support */ 382 383enum i2c_slave_event { 384 I2C_SLAVE_READ_REQUESTED, 385 I2C_SLAVE_WRITE_REQUESTED, 386 I2C_SLAVE_READ_PROCESSED, 387 I2C_SLAVE_WRITE_RECEIVED, 388 I2C_SLAVE_STOP, 389}; 390 391int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 392int i2c_slave_unregister(struct i2c_client *client); 393int i2c_slave_event(struct i2c_client *client, 394 enum i2c_slave_event event, u8 *val); 395#if IS_ENABLED(CONFIG_I2C_SLAVE) 396bool i2c_detect_slave_mode(struct device *dev); 397#else 398static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 399#endif 400 401/** 402 * struct i2c_board_info - template for device creation 403 * @type: chip type, to initialize i2c_client.name 404 * @flags: to initialize i2c_client.flags 405 * @addr: stored in i2c_client.addr 406 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 407 * @platform_data: stored in i2c_client.dev.platform_data 408 * @fwnode: device node supplied by the platform firmware 409 * @swnode: software node for the device 410 * @resources: resources associated with the device 411 * @num_resources: number of resources in the @resources array 412 * @irq: stored in i2c_client.irq 413 * 414 * I2C doesn't actually support hardware probing, although controllers and 415 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 416 * a device at a given address. Drivers commonly need more information than 417 * that, such as chip type, configuration, associated IRQ, and so on. 418 * 419 * i2c_board_info is used to build tables of information listing I2C devices 420 * that are present. This information is used to grow the driver model tree. 421 * For mainboards this is done statically using i2c_register_board_info(); 422 * bus numbers identify adapters that aren't yet available. For add-on boards, 423 * i2c_new_client_device() does this dynamically with the adapter already known. 424 */ 425struct i2c_board_info { 426 char type[I2C_NAME_SIZE]; 427 unsigned short flags; 428 unsigned short addr; 429 const char *dev_name; 430 void *platform_data; 431 struct fwnode_handle *fwnode; 432 const struct software_node *swnode; 433 const struct resource *resources; 434 unsigned int num_resources; 435 int irq; 436}; 437 438/** 439 * I2C_BOARD_INFO - macro used to list an i2c device and its address 440 * @dev_type: identifies the device type 441 * @dev_addr: the device's address on the bus. 442 * 443 * This macro initializes essential fields of a struct i2c_board_info, 444 * declaring what has been provided on a particular board. Optional 445 * fields (such as associated irq, or device-specific platform_data) 446 * are provided using conventional syntax. 447 */ 448#define I2C_BOARD_INFO(dev_type, dev_addr) \ 449 .type = dev_type, .addr = (dev_addr) 450 451 452#if IS_ENABLED(CONFIG_I2C) 453/* 454 * Add-on boards should register/unregister their devices; e.g. a board 455 * with integrated I2C, a config eeprom, sensors, and a codec that's 456 * used in conjunction with the primary hardware. 457 */ 458struct i2c_client * 459i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 460 461/* If you don't know the exact address of an I2C device, use this variant 462 * instead, which can probe for device presence in a list of possible 463 * addresses. The "probe" callback function is optional. If it is provided, 464 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 465 * a default probing method is used. 466 */ 467struct i2c_client * 468i2c_new_scanned_device(struct i2c_adapter *adap, 469 struct i2c_board_info *info, 470 unsigned short const *addr_list, 471 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 472 473/* Common custom probe functions */ 474int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 475 476struct i2c_client * 477i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 478 479struct i2c_client * 480devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 481 482struct i2c_client * 483i2c_new_ancillary_device(struct i2c_client *client, 484 const char *name, 485 u16 default_addr); 486 487void i2c_unregister_device(struct i2c_client *client); 488 489struct i2c_client *i2c_verify_client(struct device *dev); 490#else 491static inline struct i2c_client *i2c_verify_client(struct device *dev) 492{ 493 return NULL; 494} 495#endif /* I2C */ 496 497/* Mainboard arch_initcall() code should register all its I2C devices. 498 * This is done at arch_initcall time, before declaring any i2c adapters. 499 * Modules for add-on boards must use other calls. 500 */ 501#ifdef CONFIG_I2C_BOARDINFO 502int 503i2c_register_board_info(int busnum, struct i2c_board_info const *info, 504 unsigned n); 505#else 506static inline int 507i2c_register_board_info(int busnum, struct i2c_board_info const *info, 508 unsigned n) 509{ 510 return 0; 511} 512#endif /* I2C_BOARDINFO */ 513 514/** 515 * struct i2c_algorithm - represent I2C transfer methods 516 * @xfer: Transfer a given number of messages defined by the msgs array via 517 * the specified adapter. 518 * @xfer_atomic: Same as @xfer. Yet, only using atomic context so e.g. PMICs 519 * can be accessed very late before shutdown. Optional. 520 * @smbus_xfer: Issue SMBus transactions to the given I2C adapter. If this 521 * is not present, then the bus layer will try and convert the SMBus calls 522 * into I2C transfers instead. 523 * @smbus_xfer_atomic: Same as @smbus_xfer. Yet, only using atomic context 524 * so e.g. PMICs can be accessed very late before shutdown. Optional. 525 * @functionality: Return the flags that this algorithm/adapter pair supports 526 * from the ``I2C_FUNC_*`` flags. 527 * @reg_target: Register given client to local target mode of this adapter 528 * @unreg_target: Unregister given client from local target mode of this adapter 529 * 530 * @master_xfer: deprecated, use @xfer 531 * @master_xfer_atomic: deprecated, use @xfer_atomic 532 * @reg_slave: deprecated, use @reg_target 533 * @unreg_slave: deprecated, use @unreg_target 534 * 535 * i2c_algorithm is the interface to a class of hardware solutions which can 536 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 537 * to name two of the most common. 538 * 539 * The return codes from the ``xfer{_atomic}`` fields should indicate the 540 * type of error code that occurred during the transfer, as documented in the 541 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the 542 * number of messages executed should be returned. 543 */ 544struct i2c_algorithm { 545 /* 546 * If an adapter algorithm can't do I2C-level access, set xfer 547 * to NULL. If an adapter algorithm can do SMBus access, set 548 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 549 * using common I2C messages. 550 */ 551 union { 552 int (*xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 553 int num); 554 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 555 int num); 556 }; 557 union { 558 int (*xfer_atomic)(struct i2c_adapter *adap, 559 struct i2c_msg *msgs, int num); 560 int (*master_xfer_atomic)(struct i2c_adapter *adap, 561 struct i2c_msg *msgs, int num); 562 }; 563 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 564 unsigned short flags, char read_write, 565 u8 command, int size, union i2c_smbus_data *data); 566 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 567 unsigned short flags, char read_write, 568 u8 command, int size, union i2c_smbus_data *data); 569 570 /* To determine what the adapter supports */ 571 u32 (*functionality)(struct i2c_adapter *adap); 572 573#if IS_ENABLED(CONFIG_I2C_SLAVE) 574 union { 575 int (*reg_target)(struct i2c_client *client); 576 int (*reg_slave)(struct i2c_client *client); 577 }; 578 union { 579 int (*unreg_target)(struct i2c_client *client); 580 int (*unreg_slave)(struct i2c_client *client); 581 }; 582#endif 583}; 584 585/** 586 * struct i2c_lock_operations - represent I2C locking operations 587 * @lock_bus: Get exclusive access to an I2C bus segment 588 * @trylock_bus: Try to get exclusive access to an I2C bus segment 589 * @unlock_bus: Release exclusive access to an I2C bus segment 590 * 591 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 592 */ 593struct i2c_lock_operations { 594 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 595 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 596 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 597}; 598 599/** 600 * struct i2c_timings - I2C timing information 601 * @bus_freq_hz: the bus frequency in Hz 602 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 603 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 604 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 605 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 606 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 607 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 608 * digital filter can filter out 609 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 610 * analog filter 611 */ 612struct i2c_timings { 613 u32 bus_freq_hz; 614 u32 scl_rise_ns; 615 u32 scl_fall_ns; 616 u32 scl_int_delay_ns; 617 u32 sda_fall_ns; 618 u32 sda_hold_ns; 619 u32 digital_filter_width_ns; 620 u32 analog_filter_cutoff_freq_hz; 621}; 622 623/** 624 * struct i2c_bus_recovery_info - I2C bus recovery information 625 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 626 * i2c_generic_scl_recovery(). 627 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 628 * recovery. Populated internally for generic GPIO recovery. 629 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 630 * Populated internally for generic GPIO recovery. 631 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 632 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 633 * GPIO, for generic GPIO recovery. 634 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 635 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 636 * for generic GPIO recovery. 637 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 638 * has a more complex internal logic than just reading SDA. Optional. 639 * @prepare_recovery: This will be called before starting recovery. Platform may 640 * configure padmux here for SDA/SCL line or something else they want. 641 * @unprepare_recovery: This will be called after completing recovery. Platform 642 * may configure padmux here for SDA/SCL line or something else they want. 643 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 644 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 645 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 646 * Optional. 647 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 648 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 649 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 650 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 651 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 652 * is called "gpio" or "recovery" and pinctrl is valid. 653 */ 654struct i2c_bus_recovery_info { 655 int (*recover_bus)(struct i2c_adapter *adap); 656 657 int (*get_scl)(struct i2c_adapter *adap); 658 void (*set_scl)(struct i2c_adapter *adap, int val); 659 int (*get_sda)(struct i2c_adapter *adap); 660 void (*set_sda)(struct i2c_adapter *adap, int val); 661 int (*get_bus_free)(struct i2c_adapter *adap); 662 663 void (*prepare_recovery)(struct i2c_adapter *adap); 664 void (*unprepare_recovery)(struct i2c_adapter *adap); 665 666 /* gpio recovery */ 667 struct gpio_desc *scl_gpiod; 668 struct gpio_desc *sda_gpiod; 669 struct pinctrl *pinctrl; 670 struct pinctrl_state *pins_default; 671 struct pinctrl_state *pins_gpio; 672}; 673 674int i2c_recover_bus(struct i2c_adapter *adap); 675 676/* Generic recovery routines */ 677int i2c_generic_scl_recovery(struct i2c_adapter *adap); 678 679/** 680 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 681 * @flags: see I2C_AQ_* for possible flags and read below 682 * @max_num_msgs: maximum number of messages per transfer 683 * @max_write_len: maximum length of a write message 684 * @max_read_len: maximum length of a read message 685 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 686 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 687 * 688 * Note about combined messages: Some I2C controllers can only send one message 689 * per transfer, plus something called combined message or write-then-read. 690 * This is (usually) a small write message followed by a read message and 691 * barely enough to access register based devices like EEPROMs. There is a flag 692 * to support this mode. It implies max_num_msg = 2 and does the length checks 693 * with max_comb_*_len because combined message mode usually has its own 694 * limitations. Because of HW implementations, some controllers can actually do 695 * write-then-anything or other variants. To support that, write-then-read has 696 * been broken out into smaller bits like write-first and read-second which can 697 * be combined as needed. 698 */ 699 700struct i2c_adapter_quirks { 701 u64 flags; 702 int max_num_msgs; 703 u16 max_write_len; 704 u16 max_read_len; 705 u16 max_comb_1st_msg_len; 706 u16 max_comb_2nd_msg_len; 707}; 708 709/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 710#define I2C_AQ_COMB BIT(0) 711/* first combined message must be write */ 712#define I2C_AQ_COMB_WRITE_FIRST BIT(1) 713/* second combined message must be read */ 714#define I2C_AQ_COMB_READ_SECOND BIT(2) 715/* both combined messages must have the same target address */ 716#define I2C_AQ_COMB_SAME_ADDR BIT(3) 717/* convenience macro for typical write-then read case */ 718#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 719 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 720/* clock stretching is not supported */ 721#define I2C_AQ_NO_CLK_STRETCH BIT(4) 722/* message cannot have length of 0 */ 723#define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 724#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 725#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 726/* adapter cannot do repeated START */ 727#define I2C_AQ_NO_REP_START BIT(7) 728 729/* 730 * i2c_adapter is the structure used to identify a physical i2c bus along 731 * with the access algorithms necessary to access it. 732 */ 733struct i2c_adapter { 734 struct module *owner; 735 unsigned int class; /* classes to allow probing for */ 736 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 737 void *algo_data; 738 739 /* data fields that are valid for all devices */ 740 const struct i2c_lock_operations *lock_ops; 741 struct rt_mutex bus_lock; 742 struct rt_mutex mux_lock; 743 744 int timeout; /* in jiffies */ 745 int retries; 746 struct device dev; /* the adapter device */ 747 unsigned long locked_flags; /* owned by the I2C core */ 748#define I2C_ALF_IS_SUSPENDED 0 749#define I2C_ALF_SUSPEND_REPORTED 1 750 751 int nr; 752 char name[48]; 753 struct completion dev_released; 754 755 struct mutex userspace_clients_lock; 756 struct list_head userspace_clients; 757 758 struct i2c_bus_recovery_info *bus_recovery_info; 759 const struct i2c_adapter_quirks *quirks; 760 761 struct irq_domain *host_notify_domain; 762 struct regulator *bus_regulator; 763 764 struct dentry *debugfs; 765 766 /* 7bit address space */ 767 DECLARE_BITMAP(addrs_in_instantiation, 1 << 7); 768}; 769#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 770 771static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 772{ 773 return dev_get_drvdata(&adap->dev); 774} 775 776static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 777{ 778 dev_set_drvdata(&adap->dev, data); 779} 780 781static inline struct i2c_adapter * 782i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 783{ 784#if IS_ENABLED(CONFIG_I2C_MUX) 785 struct device *parent = adapter->dev.parent; 786 787 if (parent != NULL && parent->type == &i2c_adapter_type) 788 return to_i2c_adapter(parent); 789 else 790#endif 791 return NULL; 792} 793 794int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 795 796/* Adapter locking functions, exported for shared pin cases */ 797#define I2C_LOCK_ROOT_ADAPTER BIT(0) 798#define I2C_LOCK_SEGMENT BIT(1) 799 800/** 801 * i2c_lock_bus - Get exclusive access to an I2C bus segment 802 * @adapter: Target I2C bus segment 803 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 804 * locks only this branch in the adapter tree 805 */ 806static inline void 807i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 808{ 809 adapter->lock_ops->lock_bus(adapter, flags); 810} 811 812/** 813 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 814 * @adapter: Target I2C bus segment 815 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 816 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 817 * 818 * Return: true if the I2C bus segment is locked, false otherwise 819 */ 820static inline int 821i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 822{ 823 return adapter->lock_ops->trylock_bus(adapter, flags); 824} 825 826/** 827 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 828 * @adapter: Target I2C bus segment 829 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 830 * unlocks only this branch in the adapter tree 831 */ 832static inline void 833i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 834{ 835 adapter->lock_ops->unlock_bus(adapter, flags); 836} 837 838/** 839 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 840 * @adap: Adapter to mark as suspended 841 * 842 * When using this helper to mark an adapter as suspended, the core will reject 843 * further transfers to this adapter. The usage of this helper is optional but 844 * recommended for devices having distinct handlers for system suspend and 845 * runtime suspend. More complex devices are free to implement custom solutions 846 * to reject transfers when suspended. 847 */ 848static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 849{ 850 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 851 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 852 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 853} 854 855/** 856 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 857 * @adap: Adapter to mark as resumed 858 * 859 * When using this helper to mark an adapter as resumed, the core will allow 860 * further transfers to this adapter. See also further notes to 861 * @i2c_mark_adapter_suspended(). 862 */ 863static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 864{ 865 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 866 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 867 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 868} 869 870/* i2c adapter classes (bitmask) */ 871#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 872/* Warn users that the adapter doesn't support classes anymore */ 873#define I2C_CLASS_DEPRECATED (1<<8) 874 875/* Internal numbers to terminate lists */ 876#define I2C_CLIENT_END 0xfffeU 877 878/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 879#define I2C_ADDRS(addr, addrs...) \ 880 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 881 882 883/* ----- functions exported by i2c.o */ 884 885/* administration... 886 */ 887#if IS_ENABLED(CONFIG_I2C) 888int i2c_add_adapter(struct i2c_adapter *adap); 889int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); 890void i2c_del_adapter(struct i2c_adapter *adap); 891int i2c_add_numbered_adapter(struct i2c_adapter *adap); 892 893int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 894void i2c_del_driver(struct i2c_driver *driver); 895 896/* use a define to avoid include chaining to get THIS_MODULE */ 897#define i2c_add_driver(driver) \ 898 i2c_register_driver(THIS_MODULE, driver) 899 900static inline bool i2c_client_has_driver(struct i2c_client *client) 901{ 902 return !IS_ERR_OR_NULL(client) && client->dev.driver; 903} 904 905/* call the i2c_client->command() of all attached clients with 906 * the given arguments */ 907void i2c_clients_command(struct i2c_adapter *adap, 908 unsigned int cmd, void *arg); 909 910struct i2c_adapter *i2c_get_adapter(int nr); 911void i2c_put_adapter(struct i2c_adapter *adap); 912unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 913 914void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 915 916/* Return the functionality mask */ 917static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 918{ 919 return adap->algo->functionality(adap); 920} 921 922/* Return 1 if adapter supports everything we need, 0 if not. */ 923static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 924{ 925 return (func & i2c_get_functionality(adap)) == func; 926} 927 928/** 929 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 930 * @adap: i2c adapter 931 * @quirks: quirk flags 932 * 933 * Return: true if the adapter has all the specified quirk flags, false if not 934 */ 935static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 936{ 937 if (!adap->quirks) 938 return false; 939 return (adap->quirks->flags & quirks) == quirks; 940} 941 942/* Return the adapter number for a specific adapter */ 943static inline int i2c_adapter_id(struct i2c_adapter *adap) 944{ 945 return adap->nr; 946} 947 948static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 949{ 950 return (msg->addr << 1) | (msg->flags & I2C_M_RD); 951} 952 953/* 954 * 10-bit address 955 * addr_1: 5'b11110 | addr[9:8] | (R/nW) 956 * addr_2: addr[7:0] 957 */ 958static inline u8 i2c_10bit_addr_hi_from_msg(const struct i2c_msg *msg) 959{ 960 return 0xf0 | ((msg->addr & GENMASK(9, 8)) >> 7) | (msg->flags & I2C_M_RD); 961} 962 963static inline u8 i2c_10bit_addr_lo_from_msg(const struct i2c_msg *msg) 964{ 965 return msg->addr & GENMASK(7, 0); 966} 967 968u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 969void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 970 971int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 972/** 973 * module_i2c_driver() - Helper macro for registering a modular I2C driver 974 * @__i2c_driver: i2c_driver struct 975 * 976 * Helper macro for I2C drivers which do not do anything special in module 977 * init/exit. This eliminates a lot of boilerplate. Each module may only 978 * use this macro once, and calling it replaces module_init() and module_exit() 979 */ 980#define module_i2c_driver(__i2c_driver) \ 981 module_driver(__i2c_driver, i2c_add_driver, \ 982 i2c_del_driver) 983 984/** 985 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 986 * @__i2c_driver: i2c_driver struct 987 * 988 * Helper macro for I2C drivers which do not do anything special in their 989 * init. This eliminates a lot of boilerplate. Each driver may only 990 * use this macro once, and calling it replaces device_initcall(). 991 */ 992#define builtin_i2c_driver(__i2c_driver) \ 993 builtin_driver(__i2c_driver, i2c_add_driver) 994 995/* must call put_device() when done with returned i2c_client device */ 996struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode); 997 998/* must call put_device() when done with returned i2c_adapter device */ 999struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode); 1000 1001/* must call i2c_put_adapter() when done with returned i2c_adapter device */ 1002struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode); 1003 1004#else /* I2C */ 1005 1006static inline struct i2c_client * 1007i2c_find_device_by_fwnode(struct fwnode_handle *fwnode) 1008{ 1009 return NULL; 1010} 1011 1012static inline struct i2c_adapter * 1013i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode) 1014{ 1015 return NULL; 1016} 1017 1018static inline struct i2c_adapter * 1019i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode) 1020{ 1021 return NULL; 1022} 1023 1024#endif /* !I2C */ 1025 1026#if IS_ENABLED(CONFIG_OF) 1027/* must call put_device() when done with returned i2c_client device */ 1028static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 1029{ 1030 return i2c_find_device_by_fwnode(of_fwnode_handle(node)); 1031} 1032 1033/* must call put_device() when done with returned i2c_adapter device */ 1034static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 1035{ 1036 return i2c_find_adapter_by_fwnode(of_fwnode_handle(node)); 1037} 1038 1039/* must call i2c_put_adapter() when done with returned i2c_adapter device */ 1040static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 1041{ 1042 return i2c_get_adapter_by_fwnode(of_fwnode_handle(node)); 1043} 1044 1045int of_i2c_get_board_info(struct device *dev, struct device_node *node, 1046 struct i2c_board_info *info); 1047 1048#else 1049 1050static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 1051{ 1052 return NULL; 1053} 1054 1055static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 1056{ 1057 return NULL; 1058} 1059 1060static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 1061{ 1062 return NULL; 1063} 1064 1065static inline int of_i2c_get_board_info(struct device *dev, 1066 struct device_node *node, 1067 struct i2c_board_info *info) 1068{ 1069 return -ENOTSUPP; 1070} 1071 1072#endif /* CONFIG_OF */ 1073 1074struct acpi_resource; 1075struct acpi_resource_i2c_serialbus; 1076 1077#if IS_REACHABLE(CONFIG_ACPI) && IS_REACHABLE(CONFIG_I2C) 1078bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1079 struct acpi_resource_i2c_serialbus **i2c); 1080int i2c_acpi_client_count(struct acpi_device *adev); 1081u32 i2c_acpi_find_bus_speed(struct device *dev); 1082struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode, 1083 int index, 1084 struct i2c_board_info *info); 1085struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 1086bool i2c_acpi_waive_d0_probe(struct device *dev); 1087#else 1088static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1089 struct acpi_resource_i2c_serialbus **i2c) 1090{ 1091 return false; 1092} 1093static inline int i2c_acpi_client_count(struct acpi_device *adev) 1094{ 1095 return 0; 1096} 1097static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1098{ 1099 return 0; 1100} 1101static inline struct i2c_client *i2c_acpi_new_device_by_fwnode( 1102 struct fwnode_handle *fwnode, int index, 1103 struct i2c_board_info *info) 1104{ 1105 return ERR_PTR(-ENODEV); 1106} 1107static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1108{ 1109 return NULL; 1110} 1111static inline bool i2c_acpi_waive_d0_probe(struct device *dev) 1112{ 1113 return false; 1114} 1115#endif /* CONFIG_ACPI */ 1116 1117static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1118 int index, 1119 struct i2c_board_info *info) 1120{ 1121 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info); 1122} 1123 1124#endif /* _LINUX_I2C_H */
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