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 Ky��sti M��lkki <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_algorithm; 34struct i2c_adapter; 35struct i2c_client; 36struct i2c_driver; 37struct i2c_device_identity; 38union i2c_smbus_data; 39struct i2c_board_info; 40enum i2c_slave_event; 41typedef int (*i2c_slave_cb_t)(struct i2c_client *client, 42 enum i2c_slave_event event, u8 *val); 43 44/* I2C Frequency Modes */ 45#define I2C_MAX_STANDARD_MODE_FREQ 100000 46#define I2C_MAX_FAST_MODE_FREQ 400000 47#define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000 48#define I2C_MAX_TURBO_MODE_FREQ 1400000 49#define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000 50#define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000 51 52struct module; 53struct property_entry; 54 55#if IS_ENABLED(CONFIG_I2C) 56/* Return the Frequency mode string based on the bus frequency */ 57const char *i2c_freq_mode_string(u32 bus_freq_hz); 58 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 less than 64k since msg.len is u16. 65 */ 66int i2c_transfer_buffer_flags(const struct i2c_client *client, 67 char *buf, int count, u16 flags); 68 69/** 70 * i2c_master_recv - issue a single I2C message in master receive mode 71 * @client: Handle to slave device 72 * @buf: Where to store data read from slave 73 * @count: How many bytes to read, must be less than 64k since msg.len is u16 74 * 75 * Returns negative errno, or else the number of bytes read. 76 */ 77static inline int i2c_master_recv(const struct i2c_client *client, 78 char *buf, int count) 79{ 80 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 81}; 82 83/** 84 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 85 * using a DMA safe buffer 86 * @client: Handle to slave device 87 * @buf: Where to store data read from slave, must be safe to use with DMA 88 * @count: How many bytes to read, must be less than 64k since msg.len is u16 89 * 90 * Returns negative errno, or else the number of bytes read. 91 */ 92static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 93 char *buf, int count) 94{ 95 return i2c_transfer_buffer_flags(client, buf, count, 96 I2C_M_RD | I2C_M_DMA_SAFE); 97}; 98 99/** 100 * i2c_master_send - issue a single I2C message in master transmit mode 101 * @client: Handle to slave device 102 * @buf: Data that will be written to the slave 103 * @count: How many bytes to write, must be less than 64k since msg.len is u16 104 * 105 * Returns negative errno, or else the number of bytes written. 106 */ 107static inline int i2c_master_send(const struct i2c_client *client, 108 const char *buf, int count) 109{ 110 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 111}; 112 113/** 114 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 115 * using a DMA safe buffer 116 * @client: Handle to slave device 117 * @buf: Data that will be written to the slave, must be safe to use with DMA 118 * @count: How many bytes to write, must be less than 64k since msg.len is u16 119 * 120 * Returns negative errno, or else the number of bytes written. 121 */ 122static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 123 const char *buf, int count) 124{ 125 return i2c_transfer_buffer_flags(client, (char *)buf, count, 126 I2C_M_DMA_SAFE); 127}; 128 129/* Transfer num messages. 130 */ 131int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 132/* Unlocked flavor */ 133int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 134 135/* This is the very generalized SMBus access routine. You probably do not 136 want to use this, though; one of the functions below may be much easier, 137 and probably just as fast. 138 Note that we use i2c_adapter here, because you do not need a specific 139 smbus adapter to call this function. */ 140s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 141 unsigned short flags, char read_write, u8 command, 142 int protocol, union i2c_smbus_data *data); 143 144/* Unlocked flavor */ 145s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 146 unsigned short flags, char read_write, u8 command, 147 int protocol, union i2c_smbus_data *data); 148 149/* Now follow the 'nice' access routines. These also document the calling 150 conventions of i2c_smbus_xfer. */ 151 152u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count); 153s32 i2c_smbus_read_byte(const struct i2c_client *client); 154s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 155s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 156s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 157 u8 command, u8 value); 158s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 159s32 i2c_smbus_write_word_data(const struct i2c_client *client, 160 u8 command, u16 value); 161 162static inline s32 163i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 164{ 165 s32 value = i2c_smbus_read_word_data(client, command); 166 167 return (value < 0) ? value : swab16(value); 168} 169 170static inline s32 171i2c_smbus_write_word_swapped(const struct i2c_client *client, 172 u8 command, u16 value) 173{ 174 return i2c_smbus_write_word_data(client, command, swab16(value)); 175} 176 177/* Returns the number of read bytes */ 178s32 i2c_smbus_read_block_data(const struct i2c_client *client, 179 u8 command, u8 *values); 180s32 i2c_smbus_write_block_data(const struct i2c_client *client, 181 u8 command, u8 length, const u8 *values); 182/* Returns the number of read bytes */ 183s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 184 u8 command, u8 length, u8 *values); 185s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 186 u8 command, u8 length, const u8 *values); 187s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 188 u8 command, u8 length, 189 u8 *values); 190int i2c_get_device_id(const struct i2c_client *client, 191 struct i2c_device_identity *id); 192const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client); 193#endif /* I2C */ 194 195/** 196 * struct i2c_device_identity - i2c client device identification 197 * @manufacturer_id: 0 - 4095, database maintained by NXP 198 * @part_id: 0 - 511, according to manufacturer 199 * @die_revision: 0 - 7, according to manufacturer 200 */ 201struct i2c_device_identity { 202 u16 manufacturer_id; 203#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 204#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 205#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 206#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 207#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 208#define I2C_DEVICE_ID_ANALOG_DEVICES 5 209#define I2C_DEVICE_ID_STMICROELECTRONICS 6 210#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 211#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 212#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 213#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 214#define I2C_DEVICE_ID_FLIR 11 215#define I2C_DEVICE_ID_O2MICRO 12 216#define I2C_DEVICE_ID_ATMEL 13 217#define I2C_DEVICE_ID_NONE 0xffff 218 u16 part_id; 219 u8 die_revision; 220}; 221 222enum i2c_alert_protocol { 223 I2C_PROTOCOL_SMBUS_ALERT, 224 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 225}; 226 227/** 228 * enum i2c_driver_flags - Flags for an I2C device driver 229 * 230 * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe 231 */ 232enum i2c_driver_flags { 233 I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0), 234}; 235 236/** 237 * struct i2c_driver - represent an I2C device driver 238 * @class: What kind of i2c device we instantiate (for detect) 239 * @probe: Callback for device binding 240 * @remove: Callback for device unbinding 241 * @shutdown: Callback for device shutdown 242 * @alert: Alert callback, for example for the SMBus alert protocol 243 * @command: Callback for bus-wide signaling (optional) 244 * @driver: Device driver model driver 245 * @id_table: List of I2C devices supported by this driver 246 * @detect: Callback for device detection 247 * @address_list: The I2C addresses to probe (for detect) 248 * @clients: List of detected clients we created (for i2c-core use only) 249 * @flags: A bitmask of flags defined in &enum i2c_driver_flags 250 * 251 * The driver.owner field should be set to the module owner of this driver. 252 * The driver.name field should be set to the name of this driver. 253 * 254 * For automatic device detection, both @detect and @address_list must 255 * be defined. @class should also be set, otherwise only devices forced 256 * with module parameters will be created. The detect function must 257 * fill at least the name field of the i2c_board_info structure it is 258 * handed upon successful detection, and possibly also the flags field. 259 * 260 * If @detect is missing, the driver will still work fine for enumerated 261 * devices. Detected devices simply won't be supported. This is expected 262 * for the many I2C/SMBus devices which can't be detected reliably, and 263 * the ones which can always be enumerated in practice. 264 * 265 * The i2c_client structure which is handed to the @detect callback is 266 * not a real i2c_client. It is initialized just enough so that you can 267 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 268 * else with it. In particular, calling dev_dbg and friends on it is 269 * not allowed. 270 */ 271struct i2c_driver { 272 unsigned int class; 273 274 /* Standard driver model interfaces */ 275 int (*probe)(struct i2c_client *client); 276 void (*remove)(struct i2c_client *client); 277 278 279 /* driver model interfaces that don't relate to enumeration */ 280 void (*shutdown)(struct i2c_client *client); 281 282 /* Alert callback, for example for the SMBus alert protocol. 283 * The format and meaning of the data value depends on the protocol. 284 * For the SMBus alert protocol, there is a single bit of data passed 285 * as the alert response's low bit ("event flag"). 286 * For the SMBus Host Notify protocol, the data corresponds to the 287 * 16-bit payload data reported by the slave device acting as master. 288 */ 289 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 290 unsigned int data); 291 292 /* a ioctl like command that can be used to perform specific functions 293 * with the device. 294 */ 295 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 296 297 struct device_driver driver; 298 const struct i2c_device_id *id_table; 299 300 /* Device detection callback for automatic device creation */ 301 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 302 const unsigned short *address_list; 303 struct list_head clients; 304 305 u32 flags; 306}; 307#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 308 309/** 310 * struct i2c_client - represent an I2C slave device 311 * @flags: see I2C_CLIENT_* for possible flags 312 * @addr: Address used on the I2C bus connected to the parent adapter. 313 * @name: Indicates the type of the device, usually a chip name that's 314 * generic enough to hide second-sourcing and compatible revisions. 315 * @adapter: manages the bus segment hosting this I2C device 316 * @dev: Driver model device node for the slave. 317 * @init_irq: IRQ that was set at initialization 318 * @irq: indicates the IRQ generated by this device (if any) 319 * @detected: member of an i2c_driver.clients list or i2c-core's 320 * userspace_devices list 321 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 322 * calls it to pass on slave events to the slave driver. 323 * @devres_group_id: id of the devres group that will be created for resources 324 * acquired when probing this device. 325 * 326 * An i2c_client identifies a single device (i.e. chip) connected to an 327 * i2c bus. The behaviour exposed to Linux is defined by the driver 328 * managing the device. 329 */ 330struct i2c_client { 331 unsigned short flags; /* div., see below */ 332#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 333#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 334 /* Must equal I2C_M_TEN below */ 335#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 336#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 337#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 338#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 339 /* Must match I2C_M_STOP|IGNORE_NAK */ 340 341 unsigned short addr; /* chip address - NOTE: 7bit */ 342 /* addresses are stored in the */ 343 /* _LOWER_ 7 bits */ 344 char name[I2C_NAME_SIZE]; 345 struct i2c_adapter *adapter; /* the adapter we sit on */ 346 struct device dev; /* the device structure */ 347 int init_irq; /* irq set at initialization */ 348 int irq; /* irq issued by device */ 349 struct list_head detected; 350#if IS_ENABLED(CONFIG_I2C_SLAVE) 351 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 352#endif 353 void *devres_group_id; /* ID of probe devres group */ 354}; 355#define to_i2c_client(d) container_of(d, struct i2c_client, dev) 356 357struct i2c_adapter *i2c_verify_adapter(struct device *dev); 358const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 359 const struct i2c_client *client); 360 361const void *i2c_get_match_data(const struct i2c_client *client); 362 363static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 364{ 365 struct device * const dev = kobj_to_dev(kobj); 366 return to_i2c_client(dev); 367} 368 369static inline void *i2c_get_clientdata(const struct i2c_client *client) 370{ 371 return dev_get_drvdata(&client->dev); 372} 373 374static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 375{ 376 dev_set_drvdata(&client->dev, data); 377} 378 379/* I2C slave support */ 380 381enum i2c_slave_event { 382 I2C_SLAVE_READ_REQUESTED, 383 I2C_SLAVE_WRITE_REQUESTED, 384 I2C_SLAVE_READ_PROCESSED, 385 I2C_SLAVE_WRITE_RECEIVED, 386 I2C_SLAVE_STOP, 387}; 388 389int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 390int i2c_slave_unregister(struct i2c_client *client); 391int i2c_slave_event(struct i2c_client *client, 392 enum i2c_slave_event event, u8 *val); 393#if IS_ENABLED(CONFIG_I2C_SLAVE) 394bool i2c_detect_slave_mode(struct device *dev); 395#else 396static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 397#endif 398 399/** 400 * struct i2c_board_info - template for device creation 401 * @type: chip type, to initialize i2c_client.name 402 * @flags: to initialize i2c_client.flags 403 * @addr: stored in i2c_client.addr 404 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 405 * @platform_data: stored in i2c_client.dev.platform_data 406 * @of_node: pointer to OpenFirmware device node 407 * @fwnode: device node supplied by the platform firmware 408 * @swnode: software node for the device 409 * @resources: resources associated with the device 410 * @num_resources: number of resources in the @resources array 411 * @irq: stored in i2c_client.irq 412 * 413 * I2C doesn't actually support hardware probing, although controllers and 414 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 415 * a device at a given address. Drivers commonly need more information than 416 * that, such as chip type, configuration, associated IRQ, and so on. 417 * 418 * i2c_board_info is used to build tables of information listing I2C devices 419 * that are present. This information is used to grow the driver model tree. 420 * For mainboards this is done statically using i2c_register_board_info(); 421 * bus numbers identify adapters that aren't yet available. For add-on boards, 422 * i2c_new_client_device() does this dynamically with the adapter already known. 423 */ 424struct i2c_board_info { 425 char type[I2C_NAME_SIZE]; 426 unsigned short flags; 427 unsigned short addr; 428 const char *dev_name; 429 void *platform_data; 430 struct device_node *of_node; 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 method 516 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 517 * defined by the msgs array, with num messages available to transfer via 518 * the adapter specified by adap. 519 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 520 * so e.g. PMICs can be accessed very late before shutdown. Optional. 521 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 522 * is not present, then the bus layer will try and convert the SMBus calls 523 * into I2C transfers instead. 524 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 525 * so e.g. PMICs can be accessed very late before shutdown. Optional. 526 * @functionality: Return the flags that this algorithm/adapter pair supports 527 * from the ``I2C_FUNC_*`` flags. 528 * @reg_slave: Register given client to I2C slave mode of this adapter 529 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 530 * 531 * The following structs are for those who like to implement new bus drivers: 532 * i2c_algorithm is the interface to a class of hardware solutions which can 533 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 534 * to name two of the most common. 535 * 536 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 537 * type of error code that occurred during the transfer, as documented in the 538 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the 539 * number of messages executed should be returned. 540 */ 541struct i2c_algorithm { 542 /* 543 * If an adapter algorithm can't do I2C-level access, set master_xfer 544 * to NULL. If an adapter algorithm can do SMBus access, set 545 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 546 * using common I2C messages. 547 * 548 * master_xfer should return the number of messages successfully 549 * processed, or a negative value on error 550 */ 551 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 552 int num); 553 int (*master_xfer_atomic)(struct i2c_adapter *adap, 554 struct i2c_msg *msgs, int num); 555 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 556 unsigned short flags, char read_write, 557 u8 command, int size, union i2c_smbus_data *data); 558 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 559 unsigned short flags, char read_write, 560 u8 command, int size, union i2c_smbus_data *data); 561 562 /* To determine what the adapter supports */ 563 u32 (*functionality)(struct i2c_adapter *adap); 564 565#if IS_ENABLED(CONFIG_I2C_SLAVE) 566 int (*reg_slave)(struct i2c_client *client); 567 int (*unreg_slave)(struct i2c_client *client); 568#endif 569}; 570 571/** 572 * struct i2c_lock_operations - represent I2C locking operations 573 * @lock_bus: Get exclusive access to an I2C bus segment 574 * @trylock_bus: Try to get exclusive access to an I2C bus segment 575 * @unlock_bus: Release exclusive access to an I2C bus segment 576 * 577 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 578 */ 579struct i2c_lock_operations { 580 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 581 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 582 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 583}; 584 585/** 586 * struct i2c_timings - I2C timing information 587 * @bus_freq_hz: the bus frequency in Hz 588 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 589 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 590 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 591 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 592 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 593 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 594 * digital filter can filter out 595 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 596 * analog filter 597 */ 598struct i2c_timings { 599 u32 bus_freq_hz; 600 u32 scl_rise_ns; 601 u32 scl_fall_ns; 602 u32 scl_int_delay_ns; 603 u32 sda_fall_ns; 604 u32 sda_hold_ns; 605 u32 digital_filter_width_ns; 606 u32 analog_filter_cutoff_freq_hz; 607}; 608 609/** 610 * struct i2c_bus_recovery_info - I2C bus recovery information 611 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 612 * i2c_generic_scl_recovery(). 613 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 614 * recovery. Populated internally for generic GPIO recovery. 615 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 616 * Populated internally for generic GPIO recovery. 617 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 618 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 619 * GPIO, for generic GPIO recovery. 620 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 621 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 622 * for generic GPIO recovery. 623 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 624 * has a more complex internal logic than just reading SDA. Optional. 625 * @prepare_recovery: This will be called before starting recovery. Platform may 626 * configure padmux here for SDA/SCL line or something else they want. 627 * @unprepare_recovery: This will be called after completing recovery. Platform 628 * may configure padmux here for SDA/SCL line or something else they want. 629 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 630 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 631 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 632 * Optional. 633 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 634 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 635 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 636 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 637 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 638 * is called "gpio" or "recovery" and pinctrl is valid. 639 */ 640struct i2c_bus_recovery_info { 641 int (*recover_bus)(struct i2c_adapter *adap); 642 643 int (*get_scl)(struct i2c_adapter *adap); 644 void (*set_scl)(struct i2c_adapter *adap, int val); 645 int (*get_sda)(struct i2c_adapter *adap); 646 void (*set_sda)(struct i2c_adapter *adap, int val); 647 int (*get_bus_free)(struct i2c_adapter *adap); 648 649 void (*prepare_recovery)(struct i2c_adapter *adap); 650 void (*unprepare_recovery)(struct i2c_adapter *adap); 651 652 /* gpio recovery */ 653 struct gpio_desc *scl_gpiod; 654 struct gpio_desc *sda_gpiod; 655 struct pinctrl *pinctrl; 656 struct pinctrl_state *pins_default; 657 struct pinctrl_state *pins_gpio; 658}; 659 660int i2c_recover_bus(struct i2c_adapter *adap); 661 662/* Generic recovery routines */ 663int i2c_generic_scl_recovery(struct i2c_adapter *adap); 664 665/** 666 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 667 * @flags: see I2C_AQ_* for possible flags and read below 668 * @max_num_msgs: maximum number of messages per transfer 669 * @max_write_len: maximum length of a write message 670 * @max_read_len: maximum length of a read message 671 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 672 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 673 * 674 * Note about combined messages: Some I2C controllers can only send one message 675 * per transfer, plus something called combined message or write-then-read. 676 * This is (usually) a small write message followed by a read message and 677 * barely enough to access register based devices like EEPROMs. There is a flag 678 * to support this mode. It implies max_num_msg = 2 and does the length checks 679 * with max_comb_*_len because combined message mode usually has its own 680 * limitations. Because of HW implementations, some controllers can actually do 681 * write-then-anything or other variants. To support that, write-then-read has 682 * been broken out into smaller bits like write-first and read-second which can 683 * be combined as needed. 684 */ 685 686struct i2c_adapter_quirks { 687 u64 flags; 688 int max_num_msgs; 689 u16 max_write_len; 690 u16 max_read_len; 691 u16 max_comb_1st_msg_len; 692 u16 max_comb_2nd_msg_len; 693}; 694 695/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 696#define I2C_AQ_COMB BIT(0) 697/* first combined message must be write */ 698#define I2C_AQ_COMB_WRITE_FIRST BIT(1) 699/* second combined message must be read */ 700#define I2C_AQ_COMB_READ_SECOND BIT(2) 701/* both combined messages must have the same target address */ 702#define I2C_AQ_COMB_SAME_ADDR BIT(3) 703/* convenience macro for typical write-then read case */ 704#define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 705 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 706/* clock stretching is not supported */ 707#define I2C_AQ_NO_CLK_STRETCH BIT(4) 708/* message cannot have length of 0 */ 709#define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 710#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 711#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 712/* adapter cannot do repeated START */ 713#define I2C_AQ_NO_REP_START BIT(7) 714 715/* 716 * i2c_adapter is the structure used to identify a physical i2c bus along 717 * with the access algorithms necessary to access it. 718 */ 719struct i2c_adapter { 720 struct module *owner; 721 unsigned int class; /* classes to allow probing for */ 722 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 723 void *algo_data; 724 725 /* data fields that are valid for all devices */ 726 const struct i2c_lock_operations *lock_ops; 727 struct rt_mutex bus_lock; 728 struct rt_mutex mux_lock; 729 730 int timeout; /* in jiffies */ 731 int retries; 732 struct device dev; /* the adapter device */ 733 unsigned long locked_flags; /* owned by the I2C core */ 734#define I2C_ALF_IS_SUSPENDED 0 735#define I2C_ALF_SUSPEND_REPORTED 1 736 737 int nr; 738 char name[48]; 739 struct completion dev_released; 740 741 struct mutex userspace_clients_lock; 742 struct list_head userspace_clients; 743 744 struct i2c_bus_recovery_info *bus_recovery_info; 745 const struct i2c_adapter_quirks *quirks; 746 747 struct irq_domain *host_notify_domain; 748 struct regulator *bus_regulator; 749 750 struct dentry *debugfs; 751}; 752#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 753 754static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 755{ 756 return dev_get_drvdata(&adap->dev); 757} 758 759static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 760{ 761 dev_set_drvdata(&adap->dev, data); 762} 763 764static inline struct i2c_adapter * 765i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 766{ 767#if IS_ENABLED(CONFIG_I2C_MUX) 768 struct device *parent = adapter->dev.parent; 769 770 if (parent != NULL && parent->type == &i2c_adapter_type) 771 return to_i2c_adapter(parent); 772 else 773#endif 774 return NULL; 775} 776 777int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 778 779/* Adapter locking functions, exported for shared pin cases */ 780#define I2C_LOCK_ROOT_ADAPTER BIT(0) 781#define I2C_LOCK_SEGMENT BIT(1) 782 783/** 784 * i2c_lock_bus - Get exclusive access to an I2C bus segment 785 * @adapter: Target I2C bus segment 786 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 787 * locks only this branch in the adapter tree 788 */ 789static inline void 790i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 791{ 792 adapter->lock_ops->lock_bus(adapter, flags); 793} 794 795/** 796 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 797 * @adapter: Target I2C bus segment 798 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 799 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 800 * 801 * Return: true if the I2C bus segment is locked, false otherwise 802 */ 803static inline int 804i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 805{ 806 return adapter->lock_ops->trylock_bus(adapter, flags); 807} 808 809/** 810 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 811 * @adapter: Target I2C bus segment 812 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 813 * unlocks only this branch in the adapter tree 814 */ 815static inline void 816i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 817{ 818 adapter->lock_ops->unlock_bus(adapter, flags); 819} 820 821/** 822 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 823 * @adap: Adapter to mark as suspended 824 * 825 * When using this helper to mark an adapter as suspended, the core will reject 826 * further transfers to this adapter. The usage of this helper is optional but 827 * recommended for devices having distinct handlers for system suspend and 828 * runtime suspend. More complex devices are free to implement custom solutions 829 * to reject transfers when suspended. 830 */ 831static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 832{ 833 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 834 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 835 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 836} 837 838/** 839 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 840 * @adap: Adapter to mark as resumed 841 * 842 * When using this helper to mark an adapter as resumed, the core will allow 843 * further transfers to this adapter. See also further notes to 844 * @i2c_mark_adapter_suspended(). 845 */ 846static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 847{ 848 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 849 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 850 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 851} 852 853/* i2c adapter classes (bitmask) */ 854#define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 855#define I2C_CLASS_SPD (1<<7) /* Memory modules */ 856/* Warn users that the adapter doesn't support classes anymore */ 857#define I2C_CLASS_DEPRECATED (1<<8) 858 859/* Internal numbers to terminate lists */ 860#define I2C_CLIENT_END 0xfffeU 861 862/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 863#define I2C_ADDRS(addr, addrs...) \ 864 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 865 866 867/* ----- functions exported by i2c.o */ 868 869/* administration... 870 */ 871#if IS_ENABLED(CONFIG_I2C) 872int i2c_add_adapter(struct i2c_adapter *adap); 873int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); 874void i2c_del_adapter(struct i2c_adapter *adap); 875int i2c_add_numbered_adapter(struct i2c_adapter *adap); 876 877int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 878void i2c_del_driver(struct i2c_driver *driver); 879 880/* use a define to avoid include chaining to get THIS_MODULE */ 881#define i2c_add_driver(driver) \ 882 i2c_register_driver(THIS_MODULE, driver) 883 884static inline bool i2c_client_has_driver(struct i2c_client *client) 885{ 886 return !IS_ERR_OR_NULL(client) && client->dev.driver; 887} 888 889/* call the i2c_client->command() of all attached clients with 890 * the given arguments */ 891void i2c_clients_command(struct i2c_adapter *adap, 892 unsigned int cmd, void *arg); 893 894struct i2c_adapter *i2c_get_adapter(int nr); 895void i2c_put_adapter(struct i2c_adapter *adap); 896unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 897 898void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 899 900/* Return the functionality mask */ 901static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 902{ 903 return adap->algo->functionality(adap); 904} 905 906/* Return 1 if adapter supports everything we need, 0 if not. */ 907static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 908{ 909 return (func & i2c_get_functionality(adap)) == func; 910} 911 912/** 913 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 914 * @adap: i2c adapter 915 * @quirks: quirk flags 916 * 917 * Return: true if the adapter has all the specified quirk flags, false if not 918 */ 919static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 920{ 921 if (!adap->quirks) 922 return false; 923 return (adap->quirks->flags & quirks) == quirks; 924} 925 926/* Return the adapter number for a specific adapter */ 927static inline int i2c_adapter_id(struct i2c_adapter *adap) 928{ 929 return adap->nr; 930} 931 932static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 933{ 934 return (msg->addr << 1) | (msg->flags & I2C_M_RD); 935} 936 937u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 938void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 939 940int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 941/** 942 * module_i2c_driver() - Helper macro for registering a modular I2C driver 943 * @__i2c_driver: i2c_driver struct 944 * 945 * Helper macro for I2C drivers which do not do anything special in module 946 * init/exit. This eliminates a lot of boilerplate. Each module may only 947 * use this macro once, and calling it replaces module_init() and module_exit() 948 */ 949#define module_i2c_driver(__i2c_driver) \ 950 module_driver(__i2c_driver, i2c_add_driver, \ 951 i2c_del_driver) 952 953/** 954 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 955 * @__i2c_driver: i2c_driver struct 956 * 957 * Helper macro for I2C drivers which do not do anything special in their 958 * init. This eliminates a lot of boilerplate. Each driver may only 959 * use this macro once, and calling it replaces device_initcall(). 960 */ 961#define builtin_i2c_driver(__i2c_driver) \ 962 builtin_driver(__i2c_driver, i2c_add_driver) 963 964#endif /* I2C */ 965 966/* must call put_device() when done with returned i2c_client device */ 967struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode); 968 969/* must call put_device() when done with returned i2c_adapter device */ 970struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode); 971 972/* must call i2c_put_adapter() when done with returned i2c_adapter device */ 973struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode); 974 975#if IS_ENABLED(CONFIG_OF) 976/* must call put_device() when done with returned i2c_client device */ 977static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 978{ 979 return i2c_find_device_by_fwnode(of_fwnode_handle(node)); 980} 981 982/* must call put_device() when done with returned i2c_adapter device */ 983static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 984{ 985 return i2c_find_adapter_by_fwnode(of_fwnode_handle(node)); 986} 987 988/* must call i2c_put_adapter() when done with returned i2c_adapter device */ 989static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 990{ 991 return i2c_get_adapter_by_fwnode(of_fwnode_handle(node)); 992} 993 994const struct of_device_id 995*i2c_of_match_device(const struct of_device_id *matches, 996 struct i2c_client *client); 997 998int of_i2c_get_board_info(struct device *dev, struct device_node *node, 999 struct i2c_board_info *info); 1000 1001#else 1002 1003static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 1004{ 1005 return NULL; 1006} 1007 1008static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 1009{ 1010 return NULL; 1011} 1012 1013static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 1014{ 1015 return NULL; 1016} 1017 1018static inline const struct of_device_id 1019*i2c_of_match_device(const struct of_device_id *matches, 1020 struct i2c_client *client) 1021{ 1022 return NULL; 1023} 1024 1025static inline int of_i2c_get_board_info(struct device *dev, 1026 struct device_node *node, 1027 struct i2c_board_info *info) 1028{ 1029 return -ENOTSUPP; 1030} 1031 1032#endif /* CONFIG_OF */ 1033 1034struct acpi_resource; 1035struct acpi_resource_i2c_serialbus; 1036 1037#if IS_ENABLED(CONFIG_ACPI) 1038bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1039 struct acpi_resource_i2c_serialbus **i2c); 1040int i2c_acpi_client_count(struct acpi_device *adev); 1041u32 i2c_acpi_find_bus_speed(struct device *dev); 1042struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode, 1043 int index, 1044 struct i2c_board_info *info); 1045struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 1046bool i2c_acpi_waive_d0_probe(struct device *dev); 1047#else 1048static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1049 struct acpi_resource_i2c_serialbus **i2c) 1050{ 1051 return false; 1052} 1053static inline int i2c_acpi_client_count(struct acpi_device *adev) 1054{ 1055 return 0; 1056} 1057static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1058{ 1059 return 0; 1060} 1061static inline struct i2c_client *i2c_acpi_new_device_by_fwnode( 1062 struct fwnode_handle *fwnode, int index, 1063 struct i2c_board_info *info) 1064{ 1065 return ERR_PTR(-ENODEV); 1066} 1067static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1068{ 1069 return NULL; 1070} 1071static inline bool i2c_acpi_waive_d0_probe(struct device *dev) 1072{ 1073 return false; 1074} 1075#endif /* CONFIG_ACPI */ 1076 1077static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1078 int index, 1079 struct i2c_board_info *info) 1080{ 1081 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info); 1082} 1083 1084#endif /* _LINUX_I2C_H */ 1085