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/mod_devicetable.h> 15#include <linux/device.h> /* for struct device */ 16#include <linux/sched.h> /* for completion */ 17#include <linux/mutex.h> 18#include <linux/rtmutex.h> 19#include <linux/irqdomain.h> /* for Host Notify IRQ */ 20#include <linux/of.h> /* for struct device_node */ 21#include <linux/swab.h> /* for swab16 */ 22#include <uapi/linux/i2c.h> 23 24extern struct bus_type i2c_bus_type; 25extern struct device_type i2c_adapter_type; 26extern struct device_type i2c_client_type; 27 28/* --- General options ------------------------------------------------ */ 29 30struct i2c_msg; 31struct i2c_algorithm; 32struct i2c_adapter; 33struct i2c_client; 34struct i2c_driver; 35struct i2c_device_identity; 36union i2c_smbus_data; 37struct i2c_board_info; 38enum i2c_slave_event; 39typedef int (*i2c_slave_cb_t)(struct i2c_client *client, enum i2c_slave_event event, u8 *val); 40 41/* I2C Frequency Modes */ 42#define I2C_MAX_STANDARD_MODE_FREQ 100000 43#define I2C_MAX_FAST_MODE_FREQ 400000 44#define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000 45#define I2C_MAX_TURBO_MODE_FREQ 1400000 46#define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000 47#define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000 48 49struct module; 50struct property_entry; 51 52#if IS_ENABLED(CONFIG_I2C) 53/* 54 * The master routines are the ones normally used to transmit data to devices 55 * on a bus (or read from them). Apart from two basic transfer functions to 56 * transmit one message at a time, a more complex version can be used to 57 * transmit an arbitrary number of messages without interruption. 58 * @count must be less than 64k since msg.len is u16. 59 */ 60int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, int count, u16 flags); 61 62/** 63 * i2c_master_recv - issue a single I2C message in master receive mode 64 * @client: Handle to slave device 65 * @buf: Where to store data read from slave 66 * @count: How many bytes to read, must be less than 64k since msg.len is u16 67 * 68 * Returns negative errno, or else the number of bytes read. 69 */ 70static inline int i2c_master_recv(const struct i2c_client *client, char *buf, int count) 71{ 72 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 73}; 74 75/** 76 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 77 * using a DMA safe buffer 78 * @client: Handle to slave device 79 * @buf: Where to store data read from slave, must be safe to use with DMA 80 * @count: How many bytes to read, must be less than 64k since msg.len is u16 81 * 82 * Returns negative errno, or else the number of bytes read. 83 */ 84static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, char *buf, int count) 85{ 86 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD | I2C_M_DMA_SAFE); 87}; 88 89/** 90 * i2c_master_send - issue a single I2C message in master transmit mode 91 * @client: Handle to slave device 92 * @buf: Data that will be written to the slave 93 * @count: How many bytes to write, must be less than 64k since msg.len is u16 94 * 95 * Returns negative errno, or else the number of bytes written. 96 */ 97static inline int i2c_master_send(const struct i2c_client *client, const char *buf, int count) 98{ 99 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 100}; 101 102/** 103 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 104 * using a DMA safe buffer 105 * @client: Handle to slave device 106 * @buf: Data that will be written to the slave, must be safe to use with DMA 107 * @count: How many bytes to write, must be less than 64k since msg.len is u16 108 * 109 * Returns negative errno, or else the number of bytes written. 110 */ 111static inline int i2c_master_send_dmasafe(const struct i2c_client *client, const char *buf, int count) 112{ 113 return i2c_transfer_buffer_flags(client, (char *)buf, count, I2C_M_DMA_SAFE); 114}; 115 116/* Transfer num messages. 117 */ 118int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 119/* Unlocked flavor */ 120int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 121 122/* This is the very generalized SMBus access routine. You probably do not 123 want to use this, though; one of the functions below may be much easier, 124 and probably just as fast. 125 Note that we use i2c_adapter here, because you do not need a specific 126 smbus adapter to call this function. */ 127s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, char read_write, u8 command, 128 int protocol, union i2c_smbus_data *data); 129 130/* Unlocked flavor */ 131s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, char read_write, u8 command, 132 int protocol, union i2c_smbus_data *data); 133 134/* Now follow the 'nice' access routines. These also document the calling 135 conventions of i2c_smbus_xfer. */ 136 137s32 i2c_smbus_read_byte(const struct i2c_client *client); 138s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 139s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 140s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, u8 value); 141s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 142s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, u16 value); 143 144static inline s32 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 145{ 146 s32 value = i2c_smbus_read_word_data(client, command); 147 148 return (value < 0) ? value : swab16(value); 149} 150 151static inline s32 i2c_smbus_write_word_swapped(const struct i2c_client *client, u8 command, u16 value) 152{ 153 return i2c_smbus_write_word_data(client, command, swab16(value)); 154} 155 156/* Returns the number of read bytes */ 157s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, u8 *values); 158s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values); 159/* Returns the number of read bytes */ 160s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, u8 *values); 161s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values); 162s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, u8 command, u8 length, u8 *values); 163int i2c_get_device_id(const struct i2c_client *client, struct i2c_device_identity *id); 164#endif /* I2C */ 165 166/** 167 * struct i2c_device_identity - i2c client device identification 168 * @manufacturer_id: 0 - 4095, database maintained by NXP 169 * @part_id: 0 - 511, according to manufacturer 170 * @die_revision: 0 - 7, according to manufacturer 171 */ 172struct i2c_device_identity { 173 u16 manufacturer_id; 174#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 175#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 176#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 177#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 178#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 179#define I2C_DEVICE_ID_ANALOG_DEVICES 5 180#define I2C_DEVICE_ID_STMICROELECTRONICS 6 181#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 182#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 183#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 184#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 185#define I2C_DEVICE_ID_FLIR 11 186#define I2C_DEVICE_ID_O2MICRO 12 187#define I2C_DEVICE_ID_ATMEL 13 188#define I2C_DEVICE_ID_NONE 0xffff 189 u16 part_id; 190 u8 die_revision; 191}; 192 193enum i2c_alert_protocol { 194 I2C_PROTOCOL_SMBUS_ALERT, 195 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 196}; 197 198/** 199 * struct i2c_driver - represent an I2C device driver 200 * @class: What kind of i2c device we instantiate (for detect) 201 * @probe: Callback for device binding - soon to be deprecated 202 * @probe_new: New callback for device binding 203 * @remove: Callback for device unbinding 204 * @shutdown: Callback for device shutdown 205 * @alert: Alert callback, for example for the SMBus alert protocol 206 * @command: Callback for bus-wide signaling (optional) 207 * @driver: Device driver model driver 208 * @id_table: List of I2C devices supported by this driver 209 * @detect: Callback for device detection 210 * @address_list: The I2C addresses to probe (for detect) 211 * @clients: List of detected clients we created (for i2c-core use only) 212 * 213 * The driver.owner field should be set to the module owner of this driver. 214 * The driver.name field should be set to the name of this driver. 215 * 216 * For automatic device detection, both @detect and @address_list must 217 * be defined. @class should also be set, otherwise only devices forced 218 * with module parameters will be created. The detect function must 219 * fill at least the name field of the i2c_board_info structure it is 220 * handed upon successful detection, and possibly also the flags field. 221 * 222 * If @detect is missing, the driver will still work fine for enumerated 223 * devices. Detected devices simply won't be supported. This is expected 224 * for the many I2C/SMBus devices which can't be detected reliably, and 225 * the ones which can always be enumerated in practice. 226 * 227 * The i2c_client structure which is handed to the @detect callback is 228 * not a real i2c_client. It is initialized just enough so that you can 229 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 230 * else with it. In particular, calling dev_dbg and friends on it is 231 * not allowed. 232 */ 233struct i2c_driver { 234 unsigned int class; 235 236 /* Standard driver model interfaces */ 237 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id); 238 int (*remove)(struct i2c_client *client); 239 240 /* New driver model interface to aid the seamless removal of the 241 * current probe()'s, more commonly unused than used second parameter. 242 */ 243 int (*probe_new)(struct i2c_client *client); 244 245 /* driver model interfaces that don't relate to enumeration */ 246 void (*shutdown)(struct i2c_client *client); 247 248 /* Alert callback, for example for the SMBus alert protocol. 249 * The format and meaning of the data value depends on the protocol. 250 * For the SMBus alert protocol, there is a single bit of data passed 251 * as the alert response's low bit ("event flag"). 252 * For the SMBus Host Notify protocol, the data corresponds to the 253 * 16-bit payload data reported by the slave device acting as master. 254 */ 255 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, unsigned int data); 256 257 /* a ioctl like command that can be used to perform specific functions 258 * with the device. 259 */ 260 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 261 262 struct device_driver driver; 263 const struct i2c_device_id *id_table; 264 265 /* Device detection callback for automatic device creation */ 266 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 267 const unsigned short *address_list; 268 struct list_head clients; 269}; 270#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 271 272/** 273 * struct i2c_client - represent an I2C slave device 274 * @flags: see I2C_CLIENT_* for possible flags 275 * @addr: Address used on the I2C bus connected to the parent adapter. 276 * @name: Indicates the type of the device, usually a chip name that's 277 * generic enough to hide second-sourcing and compatible revisions. 278 * @adapter: manages the bus segment hosting this I2C device 279 * @dev: Driver model device node for the slave. 280 * @init_irq: IRQ that was set at initialization 281 * @irq: indicates the IRQ generated by this device (if any) 282 * @detected: member of an i2c_driver.clients list or i2c-core's 283 * userspace_devices list 284 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 285 * calls it to pass on slave events to the slave driver. 286 * 287 * An i2c_client identifies a single device (i.e. chip) connected to an 288 * i2c bus. The behaviour exposed to Linux is defined by the driver 289 * managing the device. 290 */ 291struct i2c_client { 292 unsigned short flags; /* div., see below */ 293#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 294#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 295 /* Must equal I2C_M_TEN below */ 296#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 297#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 298#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 299#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 300 /* Must match I2C_M_STOP|IGNORE_NAK */ 301 302 unsigned short addr; /* chip address - NOTE: 7bit */ 303 /* addresses are stored in the */ 304 /* _LOWER_ 7 bits */ 305 char name[I2C_NAME_SIZE]; 306 struct i2c_adapter *adapter; /* the adapter we sit on */ 307 struct device dev; /* the device structure */ 308 int init_irq; /* irq set at initialization */ 309 int irq; /* irq issued by device */ 310 struct list_head detected; 311#if IS_ENABLED(CONFIG_I2C_SLAVE) 312 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 313#endif 314}; 315#define to_i2c_client(d) container_of(d, struct i2c_client, dev) 316 317struct i2c_client *i2c_verify_client(struct device *dev); 318struct i2c_adapter *i2c_verify_adapter(struct device *dev); 319const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, const struct i2c_client *client); 320 321static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 322{ 323 struct device *const dev = kobj_to_dev(kobj); 324 return to_i2c_client(dev); 325} 326 327static inline void *i2c_get_clientdata(const struct i2c_client *client) 328{ 329 return dev_get_drvdata(&client->dev); 330} 331 332static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 333{ 334 dev_set_drvdata(&client->dev, data); 335} 336 337/* I2C slave support */ 338 339#if IS_ENABLED(CONFIG_I2C_SLAVE) 340enum i2c_slave_event { 341 I2C_SLAVE_READ_REQUESTED, 342 I2C_SLAVE_WRITE_REQUESTED, 343 I2C_SLAVE_READ_PROCESSED, 344 I2C_SLAVE_WRITE_RECEIVED, 345 I2C_SLAVE_STOP, 346}; 347 348int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 349int i2c_slave_unregister(struct i2c_client *client); 350bool i2c_detect_slave_mode(struct device *dev); 351 352static inline int i2c_slave_event(struct i2c_client *client, enum i2c_slave_event event, u8 *val) 353{ 354 return client->slave_cb(client, event, val); 355} 356#else 357static inline bool i2c_detect_slave_mode(struct device *dev) 358{ 359 return false; 360} 361#endif 362 363/** 364 * struct i2c_board_info - template for device creation 365 * @type: chip type, to initialize i2c_client.name 366 * @flags: to initialize i2c_client.flags 367 * @addr: stored in i2c_client.addr 368 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 369 * @platform_data: stored in i2c_client.dev.platform_data 370 * @of_node: pointer to OpenFirmware device node 371 * @fwnode: device node supplied by the platform firmware 372 * @properties: additional device properties for the device 373 * @resources: resources associated with the device 374 * @num_resources: number of resources in the @resources array 375 * @irq: stored in i2c_client.irq 376 * 377 * I2C doesn't actually support hardware probing, although controllers and 378 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 379 * a device at a given address. Drivers commonly need more information than 380 * that, such as chip type, configuration, associated IRQ, and so on. 381 * 382 * i2c_board_info is used to build tables of information listing I2C devices 383 * that are present. This information is used to grow the driver model tree. 384 * For mainboards this is done statically using i2c_register_board_info(); 385 * bus numbers identify adapters that aren't yet available. For add-on boards, 386 * i2c_new_client_device() does this dynamically with the adapter already known. 387 */ 388struct i2c_board_info { 389 char type[I2C_NAME_SIZE]; 390 unsigned short flags; 391 unsigned short addr; 392 const char *dev_name; 393 void *platform_data; 394 struct device_node *of_node; 395 struct fwnode_handle *fwnode; 396 const struct property_entry *properties; 397 const struct resource *resources; 398 unsigned int num_resources; 399 int irq; 400}; 401 402/** 403 * I2C_BOARD_INFO - macro used to list an i2c device and its address 404 * @dev_type: identifies the device type 405 * @dev_addr: the device's address on the bus. 406 * 407 * This macro initializes essential fields of a struct i2c_board_info, 408 * declaring what has been provided on a particular board. Optional 409 * fields (such as associated irq, or device-specific platform_data) 410 * are provided using conventional syntax. 411 */ 412#define I2C_BOARD_INFO(dev_type, dev_addr) .type = (dev_type), .addr = (dev_addr) 413 414#if IS_ENABLED(CONFIG_I2C) 415/* 416 * Add-on boards should register/unregister their devices; e.g. a board 417 * with integrated I2C, a config eeprom, sensors, and a codec that's 418 * used in conjunction with the primary hardware. 419 */ 420struct i2c_client *i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 421 422/* If you don't know the exact address of an I2C device, use this variant 423 * instead, which can probe for device presence in a list of possible 424 * addresses. The "probe" callback function is optional. If it is provided, 425 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 426 * a default probing method is used. 427 */ 428struct i2c_client *i2c_new_scanned_device(struct i2c_adapter *adap, struct i2c_board_info *info, 429 unsigned short const *addr_list, 430 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 431 432/* Common custom probe functions */ 433int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 434 435struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 436 437struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 438 439struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, const char *name, u16 default_addr); 440 441void i2c_unregister_device(struct i2c_client *client); 442#endif /* I2C */ 443 444/* Mainboard arch_initcall() code should register all its I2C devices. 445 * This is done at arch_initcall time, before declaring any i2c adapters. 446 * Modules for add-on boards must use other calls. 447 */ 448#ifdef CONFIG_I2C_BOARDINFO 449int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned n); 450#else 451static inline int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned n) 452{ 453 return 0; 454} 455#endif /* I2C_BOARDINFO */ 456 457/** 458 * struct i2c_algorithm - represent I2C transfer method 459 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 460 * defined by the msgs array, with num messages available to transfer via 461 * the adapter specified by adap. 462 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 463 * so e.g. PMICs can be accessed very late before shutdown. Optional. 464 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 465 * is not present, then the bus layer will try and convert the SMBus calls 466 * into I2C transfers instead. 467 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 468 * so e.g. PMICs can be accessed very late before shutdown. Optional. 469 * @functionality: Return the flags that this algorithm/adapter pair supports 470 * from the ``I2C_FUNC_*`` flags. 471 * @reg_slave: Register given client to I2C slave mode of this adapter 472 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 473 * 474 * The following structs are for those who like to implement new bus drivers: 475 * i2c_algorithm is the interface to a class of hardware solutions which can 476 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 477 * to name two of the most common. 478 * 479 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 480 * type of error code that occurred during the transfer, as documented in the 481 * Kernel Documentation file Documentation/i2c/fault-codes.rst. 482 */ 483struct i2c_algorithm { 484 /* 485 * If an adapter algorithm can't do I2C-level access, set master_xfer 486 * to NULL. If an adapter algorithm can do SMBus access, set 487 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 488 * using common I2C messages. 489 * 490 * master_xfer should return the number of messages successfully 491 * processed, or a negative value on error 492 */ 493 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 494 int (*master_xfer_atomic)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 495 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, 496 union i2c_smbus_data *data); 497 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, 498 int size, union i2c_smbus_data *data); 499 500 /* To determine what the adapter supports */ 501 u32 (*functionality)(struct i2c_adapter *adap); 502 503#if IS_ENABLED(CONFIG_I2C_SLAVE) 504 int (*reg_slave)(struct i2c_client *client); 505 int (*unreg_slave)(struct i2c_client *client); 506#endif 507}; 508 509/** 510 * struct i2c_lock_operations - represent I2C locking operations 511 * @lock_bus: Get exclusive access to an I2C bus segment 512 * @trylock_bus: Try to get exclusive access to an I2C bus segment 513 * @unlock_bus: Release exclusive access to an I2C bus segment 514 * 515 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 516 */ 517struct i2c_lock_operations { 518 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 519 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 520 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 521}; 522 523/** 524 * struct i2c_timings - I2C timing information 525 * @bus_freq_hz: the bus frequency in Hz 526 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 527 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 528 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 529 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 530 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 531 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 532 * digital filter can filter out 533 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 534 * analog filter 535 */ 536struct i2c_timings { 537 u32 bus_freq_hz; 538 u32 scl_rise_ns; 539 u32 scl_fall_ns; 540 u32 scl_int_delay_ns; 541 u32 sda_fall_ns; 542 u32 sda_hold_ns; 543 u32 digital_filter_width_ns; 544 u32 analog_filter_cutoff_freq_hz; 545}; 546 547/** 548 * struct i2c_bus_recovery_info - I2C bus recovery information 549 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 550 * i2c_generic_scl_recovery(). 551 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 552 * recovery. Populated internally for generic GPIO recovery. 553 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 554 * Populated internally for generic GPIO recovery. 555 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 556 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 557 * GPIO, for generic GPIO recovery. 558 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 559 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 560 * for generic GPIO recovery. 561 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 562 * has a more complex internal logic than just reading SDA. Optional. 563 * @prepare_recovery: This will be called before starting recovery. Platform may 564 * configure padmux here for SDA/SCL line or something else they want. 565 * @unprepare_recovery: This will be called after completing recovery. Platform 566 * may configure padmux here for SDA/SCL line or something else they want. 567 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 568 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 569 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 570 * Optional. 571 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 572 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 573 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 574 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 575 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 576 * is called "gpio" or "recovery" and pinctrl is valid. 577 */ 578struct i2c_bus_recovery_info { 579 int (*recover_bus)(struct i2c_adapter *adap); 580 581 int (*get_scl)(struct i2c_adapter *adap); 582 void (*set_scl)(struct i2c_adapter *adap, int val); 583 int (*get_sda)(struct i2c_adapter *adap); 584 void (*set_sda)(struct i2c_adapter *adap, int val); 585 int (*get_bus_free)(struct i2c_adapter *adap); 586 587 void (*prepare_recovery)(struct i2c_adapter *adap); 588 void (*unprepare_recovery)(struct i2c_adapter *adap); 589 590 /* gpio recovery */ 591 struct gpio_desc *scl_gpiod; 592 struct gpio_desc *sda_gpiod; 593 struct pinctrl *pinctrl; 594 struct pinctrl_state *pins_default; 595 struct pinctrl_state *pins_gpio; 596}; 597 598int i2c_recover_bus(struct i2c_adapter *adap); 599 600/* Generic recovery routines */ 601int i2c_generic_scl_recovery(struct i2c_adapter *adap); 602 603/** 604 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 605 * @flags: see I2C_AQ_* for possible flags and read below 606 * @max_num_msgs: maximum number of messages per transfer 607 * @max_write_len: maximum length of a write message 608 * @max_read_len: maximum length of a read message 609 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 610 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 611 * 612 * Note about combined messages: Some I2C controllers can only send one message 613 * per transfer, plus something called combined message or write-then-read. 614 * This is (usually) a small write message followed by a read message and 615 * barely enough to access register based devices like EEPROMs. There is a flag 616 * to support this mode. It implies max_num_msg = 2 and does the length checks 617 * with max_comb_*_len because combined message mode usually has its own 618 * limitations. Because of HW implementations, some controllers can actually do 619 * write-then-anything or other variants. To support that, write-then-read has 620 * been broken out into smaller bits like write-first and read-second which can 621 * be combined as needed. 622 */ 623 624struct i2c_adapter_quirks { 625 u64 flags; 626 int max_num_msgs; 627 u16 max_write_len; 628 u16 max_read_len; 629 u16 max_comb_1st_msg_len; 630 u16 max_comb_2nd_msg_len; 631}; 632 633/* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 634#define I2C_AQ_COMB BIT(0) 635/* first combined message must be write */ 636#define I2C_AQ_COMB_WRITE_FIRST BIT(1) 637/* second combined message must be read */ 638#define I2C_AQ_COMB_READ_SECOND BIT(2) 639/* both combined messages must have the same target address */ 640#define I2C_AQ_COMB_SAME_ADDR BIT(3) 641/* convenience macro for typical write-then read case */ 642#define I2C_AQ_COMB_WRITE_THEN_READ \ 643 (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 644/* clock stretching is not supported */ 645#define I2C_AQ_NO_CLK_STRETCH BIT(4) 646/* message cannot have length of 0 */ 647#define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 648#define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 649#define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 650/* adapter cannot do repeated START */ 651#define I2C_AQ_NO_REP_START BIT(7) 652 653/* 654 * i2c_adapter is the structure used to identify a physical i2c bus along 655 * with the access algorithms necessary to access it. 656 */ 657struct i2c_adapter { 658 struct module *owner; 659 unsigned int class; /* classes to allow probing for */ 660 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 661 void *algo_data; 662 663 /* data fields that are valid for all devices */ 664 const struct i2c_lock_operations *lock_ops; 665 struct rt_mutex bus_lock; 666 struct rt_mutex mux_lock; 667 668 int timeout; /* in jiffies */ 669 int retries; 670 struct device dev; /* the adapter device */ 671 unsigned long locked_flags; /* owned by the I2C core */ 672#define I2C_ALF_IS_SUSPENDED 0 673#define I2C_ALF_SUSPEND_REPORTED 1 674 675 int nr; 676 char name[48]; 677 struct completion dev_released; 678 679 struct mutex userspace_clients_lock; 680 struct list_head userspace_clients; 681 682 struct i2c_bus_recovery_info *bus_recovery_info; 683 const struct i2c_adapter_quirks *quirks; 684 685 struct irq_domain *host_notify_domain; 686}; 687#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 688 689static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 690{ 691 return dev_get_drvdata(&adap->dev); 692} 693 694static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 695{ 696 dev_set_drvdata(&adap->dev, data); 697} 698 699static inline struct i2c_adapter *i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 700{ 701#if IS_ENABLED(CONFIG_I2C_MUX) 702 struct device *parent = adapter->dev.parent; 703 704 if (parent != NULL && parent->type == &i2c_adapter_type) { 705 return to_i2c_adapter(parent); 706 } else 707#endif 708 return NULL; 709} 710 711int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 712 713/* Adapter locking functions, exported for shared pin cases */ 714#define I2C_LOCK_ROOT_ADAPTER BIT(0) 715#define I2C_LOCK_SEGMENT BIT(1) 716 717/** 718 * i2c_lock_bus - Get exclusive access to an I2C bus segment 719 * @adapter: Target I2C bus segment 720 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 721 * locks only this branch in the adapter tree 722 */ 723static inline void i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 724{ 725 adapter->lock_ops->lock_bus(adapter, flags); 726} 727 728/** 729 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 730 * @adapter: Target I2C bus segment 731 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 732 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 733 * 734 * Return: true if the I2C bus segment is locked, false otherwise 735 */ 736static inline int i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 737{ 738 return adapter->lock_ops->trylock_bus(adapter, flags); 739} 740 741/** 742 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 743 * @adapter: Target I2C bus segment 744 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 745 * unlocks only this branch in the adapter tree 746 */ 747static inline void i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 748{ 749 adapter->lock_ops->unlock_bus(adapter, flags); 750} 751 752/** 753 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 754 * @adap: Adapter to mark as suspended 755 * 756 * When using this helper to mark an adapter as suspended, the core will reject 757 * further transfers to this adapter. The usage of this helper is optional but 758 * recommended for devices having distinct handlers for system suspend and 759 * runtime suspend. More complex devices are free to implement custom solutions 760 * to reject transfers when suspended. 761 */ 762static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 763{ 764 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 765 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 766 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 767} 768 769/** 770 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 771 * @adap: Adapter to mark as resumed 772 * 773 * When using this helper to mark an adapter as resumed, the core will allow 774 * further transfers to this adapter. See also further notes to 775 * @i2c_mark_adapter_suspended(). 776 */ 777static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 778{ 779 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 780 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 781 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 782} 783 784/* i2c adapter classes (bitmask) */ 785#define I2C_CLASS_HWMON (1 << 0) /* lm_sensors, ... */ 786#define I2C_CLASS_DDC (1 << 3) /* DDC bus on graphics adapters */ 787#define I2C_CLASS_SPD (1 << 7) /* Memory modules */ 788/* Warn users that the adapter doesn't support classes anymore */ 789#define I2C_CLASS_DEPRECATED (1 << 8) 790 791/* Internal numbers to terminate lists */ 792#define I2C_CLIENT_END 0xfffeU 793 794/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 795#define I2C_ADDRS(addr, addrs...) ((const unsigned short[]) {addr, ##addrs, I2C_CLIENT_END}) 796 797/* ----- functions exported by i2c.o */ 798 799/* administration... 800 */ 801#if IS_ENABLED(CONFIG_I2C) 802int i2c_add_adapter(struct i2c_adapter *adap); 803void i2c_del_adapter(struct i2c_adapter *adap); 804int i2c_add_numbered_adapter(struct i2c_adapter *adap); 805 806int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 807void i2c_del_driver(struct i2c_driver *driver); 808 809/* use a define to avoid include chaining to get THIS_MODULE */ 810#define i2c_add_driver(driver) i2c_register_driver(THIS_MODULE, driver) 811 812static inline bool i2c_client_has_driver(struct i2c_client *client) 813{ 814 return !IS_ERR_OR_NULL(client) && client->dev.driver; 815} 816 817/* call the i2c_client->command() of all attached clients with 818 * the given arguments */ 819void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg); 820 821struct i2c_adapter *i2c_get_adapter(int nr); 822void i2c_put_adapter(struct i2c_adapter *adap); 823unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 824 825void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 826 827/* Return the functionality mask */ 828static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 829{ 830 return adap->algo->functionality(adap); 831} 832 833/* Return 1 if adapter supports everything we need, 0 if not. */ 834static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 835{ 836 return (func & i2c_get_functionality(adap)) == func; 837} 838 839/** 840 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 841 * @adap: i2c adapter 842 * @quirks: quirk flags 843 * 844 * Return: true if the adapter has all the specified quirk flags, false if not 845 */ 846static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 847{ 848 if (!adap->quirks) { 849 return false; 850 } 851 return (adap->quirks->flags & quirks) == quirks; 852} 853 854/* Return the adapter number for a specific adapter */ 855static inline int i2c_adapter_id(struct i2c_adapter *adap) 856{ 857 return adap->nr; 858} 859 860static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 861{ 862 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 863} 864 865u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 866void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 867 868int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 869/** 870 * module_i2c_driver() - Helper macro for registering a modular I2C driver 871 * @__i2c_driver: i2c_driver struct 872 * 873 * Helper macro for I2C drivers which do not do anything special in module 874 * init/exit. This eliminates a lot of boilerplate. Each module may only 875 * use this macro once, and calling it replaces module_init() and module_exit() 876 */ 877#define module_i2c_driver(__i2c_driver) module_driver(__i2c_driver, i2c_add_driver, i2c_del_driver) 878 879/** 880 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 881 * @__i2c_driver: i2c_driver struct 882 * 883 * Helper macro for I2C drivers which do not do anything special in their 884 * init. This eliminates a lot of boilerplate. Each driver may only 885 * use this macro once, and calling it replaces device_initcall(). 886 */ 887#define builtin_i2c_driver(__i2c_driver) builtin_driver(__i2c_driver, i2c_add_driver) 888 889#endif /* I2C */ 890 891#if IS_ENABLED(CONFIG_OF) 892/* must call put_device() when done with returned i2c_client device */ 893struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 894 895/* must call put_device() when done with returned i2c_adapter device */ 896struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 897 898/* must call i2c_put_adapter() when done with returned i2c_adapter device */ 899struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 900 901const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches, struct i2c_client *client); 902 903int of_i2c_get_board_info(struct device *dev, struct device_node *node, struct i2c_board_info *info); 904 905#else 906 907static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 908{ 909 return NULL; 910} 911 912static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 913{ 914 return NULL; 915} 916 917static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 918{ 919 return NULL; 920} 921 922static inline const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches, 923 struct i2c_client *client) 924{ 925 return NULL; 926} 927 928static inline int of_i2c_get_board_info(struct device *dev, struct device_node *node, struct i2c_board_info *info) 929{ 930 return -ENOTSUPP; 931} 932 933#endif /* CONFIG_OF */ 934 935struct acpi_resource; 936struct acpi_resource_i2c_serialbus; 937 938#if IS_ENABLED(CONFIG_ACPI) 939bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, struct acpi_resource_i2c_serialbus **i2c); 940u32 i2c_acpi_find_bus_speed(struct device *dev); 941struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, struct i2c_board_info *info); 942struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 943#else 944static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, struct acpi_resource_i2c_serialbus **i2c) 945{ 946 return false; 947} 948static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 949{ 950 return 0; 951} 952static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, struct i2c_board_info *info) 953{ 954 return ERR_PTR(-ENODEV); 955} 956static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 957{ 958 return NULL; 959} 960#endif /* CONFIG_ACPI */ 961 962#endif /* _LINUX_I2C_H */ 963