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 24 extern struct bus_type i2c_bus_type; 25 extern struct device_type i2c_adapter_type; 26 extern struct device_type i2c_client_type; 27 28 /* --- General options ------------------------------------------------ */ 29 30 struct i2c_msg; 31 struct i2c_algorithm; 32 struct i2c_adapter; 33 struct i2c_client; 34 struct i2c_driver; 35 struct i2c_device_identity; 36 union i2c_smbus_data; 37 struct i2c_board_info; 38 enum i2c_slave_event; 39 typedef int (*i2c_slave_cb_t)(struct i2c_client *client, 40 enum i2c_slave_event event, u8 *val); 41 42 /* I2C Frequency Modes */ 43 #define I2C_MAX_STANDARD_MODE_FREQ 100000 44 #define I2C_MAX_FAST_MODE_FREQ 400000 45 #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000 46 #define I2C_MAX_TURBO_MODE_FREQ 1400000 47 #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000 48 #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000 49 50 struct module; 51 struct property_entry; 52 53 #if IS_ENABLED(CONFIG_I2C) 54 /* 55 * The master routines are the ones normally used to transmit data to devices 56 * on a bus (or read from them). Apart from two basic transfer functions to 57 * transmit one message at a time, a more complex version can be used to 58 * transmit an arbitrary number of messages without interruption. 59 * @count must be less than 64k since msg.len is u16. 60 */ 61 int i2c_transfer_buffer_flags(const struct i2c_client *client, 62 char *buf, int count, u16 flags); 63 64 /** 65 * i2c_master_recv - issue a single I2C message in master receive mode 66 * @client: Handle to slave device 67 * @buf: Where to store data read from slave 68 * @count: How many bytes to read, must be less than 64k since msg.len is u16 69 * 70 * Returns negative errno, or else the number of bytes read. 71 */ 72 static inline int i2c_master_recv(const struct i2c_client *client, 73 char *buf, int count) 74 { 75 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 76 }; 77 78 /** 79 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 80 * using a DMA safe buffer 81 * @client: Handle to slave device 82 * @buf: Where to store data read from slave, must be safe to use with DMA 83 * @count: How many bytes to read, must be less than 64k since msg.len is u16 84 * 85 * Returns negative errno, or else the number of bytes read. 86 */ 87 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 88 char *buf, int count) 89 { 90 return i2c_transfer_buffer_flags(client, buf, count, 91 I2C_M_RD | I2C_M_DMA_SAFE); 92 }; 93 94 /** 95 * i2c_master_send - issue a single I2C message in master transmit mode 96 * @client: Handle to slave device 97 * @buf: Data that will be written to the slave 98 * @count: How many bytes to write, must be less than 64k since msg.len is u16 99 * 100 * Returns negative errno, or else the number of bytes written. 101 */ 102 static inline int i2c_master_send(const struct i2c_client *client, 103 const char *buf, int count) 104 { 105 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 106 }; 107 108 /** 109 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 110 * using a DMA safe buffer 111 * @client: Handle to slave device 112 * @buf: Data that will be written to the slave, must be safe to use with DMA 113 * @count: How many bytes to write, must be less than 64k since msg.len is u16 114 * 115 * Returns negative errno, or else the number of bytes written. 116 */ 117 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 118 const char *buf, int count) 119 { 120 return i2c_transfer_buffer_flags(client, (char *)buf, count, 121 I2C_M_DMA_SAFE); 122 }; 123 124 /* Transfer num messages. 125 */ 126 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 127 /* Unlocked flavor */ 128 int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 129 130 /* This is the very generalized SMBus access routine. You probably do not 131 want to use this, though; one of the functions below may be much easier, 132 and probably just as fast. 133 Note that we use i2c_adapter here, because you do not need a specific 134 smbus adapter to call this function. */ 135 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 136 unsigned short flags, char read_write, u8 command, 137 int protocol, union i2c_smbus_data *data); 138 139 /* Unlocked flavor */ 140 s32 __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 /* Now follow the 'nice' access routines. These also document the calling 145 conventions of i2c_smbus_xfer. */ 146 147 s32 i2c_smbus_read_byte(const struct i2c_client *client); 148 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 149 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 150 s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 151 u8 command, u8 value); 152 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 153 s32 i2c_smbus_write_word_data(const struct i2c_client *client, 154 u8 command, u16 value); 155 156 static inline s32 157 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 158 { 159 s32 value = i2c_smbus_read_word_data(client, command); 160 161 return (value < 0) ? value : swab16(value); 162 } 163 164 static inline s32 165 i2c_smbus_write_word_swapped(const struct i2c_client *client, 166 u8 command, u16 value) 167 { 168 return i2c_smbus_write_word_data(client, command, swab16(value)); 169 } 170 171 /* Returns the number of read bytes */ 172 s32 i2c_smbus_read_block_data(const struct i2c_client *client, 173 u8 command, u8 *values); 174 s32 i2c_smbus_write_block_data(const struct i2c_client *client, 175 u8 command, u8 length, const u8 *values); 176 /* Returns the number of read bytes */ 177 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 178 u8 command, u8 length, u8 *values); 179 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 180 u8 command, u8 length, const u8 *values); 181 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 182 u8 command, u8 length, 183 u8 *values); 184 int i2c_get_device_id(const struct i2c_client *client, 185 struct i2c_device_identity *id); 186 #endif /* I2C */ 187 188 /** 189 * struct i2c_device_identity - i2c client device identification 190 * @manufacturer_id: 0 - 4095, database maintained by NXP 191 * @part_id: 0 - 511, according to manufacturer 192 * @die_revision: 0 - 7, according to manufacturer 193 */ 194 struct i2c_device_identity { 195 u16 manufacturer_id; 196 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 197 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 198 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 199 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 200 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 201 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 202 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 203 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 204 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 205 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 206 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 207 #define I2C_DEVICE_ID_FLIR 11 208 #define I2C_DEVICE_ID_O2MICRO 12 209 #define I2C_DEVICE_ID_ATMEL 13 210 #define I2C_DEVICE_ID_NONE 0xffff 211 u16 part_id; 212 u8 die_revision; 213 }; 214 215 enum i2c_alert_protocol { 216 I2C_PROTOCOL_SMBUS_ALERT, 217 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 218 }; 219 220 /** 221 * struct i2c_driver - represent an I2C device driver 222 * @class: What kind of i2c device we instantiate (for detect) 223 * @probe: Callback for device binding - soon to be deprecated 224 * @probe_new: New callback for device binding 225 * @remove: Callback for device unbinding 226 * @shutdown: Callback for device shutdown 227 * @alert: Alert callback, for example for the SMBus alert protocol 228 * @command: Callback for bus-wide signaling (optional) 229 * @driver: Device driver model driver 230 * @id_table: List of I2C devices supported by this driver 231 * @detect: Callback for device detection 232 * @address_list: The I2C addresses to probe (for detect) 233 * @clients: List of detected clients we created (for i2c-core use only) 234 * 235 * The driver.owner field should be set to the module owner of this driver. 236 * The driver.name field should be set to the name of this driver. 237 * 238 * For automatic device detection, both @detect and @address_list must 239 * be defined. @class should also be set, otherwise only devices forced 240 * with module parameters will be created. The detect function must 241 * fill at least the name field of the i2c_board_info structure it is 242 * handed upon successful detection, and possibly also the flags field. 243 * 244 * If @detect is missing, the driver will still work fine for enumerated 245 * devices. Detected devices simply won't be supported. This is expected 246 * for the many I2C/SMBus devices which can't be detected reliably, and 247 * the ones which can always be enumerated in practice. 248 * 249 * The i2c_client structure which is handed to the @detect callback is 250 * not a real i2c_client. It is initialized just enough so that you can 251 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 252 * else with it. In particular, calling dev_dbg and friends on it is 253 * not allowed. 254 */ 255 struct i2c_driver { 256 unsigned int class; 257 258 /* Standard driver model interfaces */ 259 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id); 260 int (*remove)(struct i2c_client *client); 261 262 /* New driver model interface to aid the seamless removal of the 263 * current probe()'s, more commonly unused than used second parameter. 264 */ 265 int (*probe_new)(struct i2c_client *client); 266 267 /* driver model interfaces that don't relate to enumeration */ 268 void (*shutdown)(struct i2c_client *client); 269 270 /* Alert callback, for example for the SMBus alert protocol. 271 * The format and meaning of the data value depends on the protocol. 272 * For the SMBus alert protocol, there is a single bit of data passed 273 * as the alert response's low bit ("event flag"). 274 * For the SMBus Host Notify protocol, the data corresponds to the 275 * 16-bit payload data reported by the slave device acting as master. 276 */ 277 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 278 unsigned int data); 279 280 /* a ioctl like command that can be used to perform specific functions 281 * with the device. 282 */ 283 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 284 285 struct device_driver driver; 286 const struct i2c_device_id *id_table; 287 288 /* Device detection callback for automatic device creation */ 289 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 290 const unsigned short *address_list; 291 struct list_head clients; 292 }; 293 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 294 295 /** 296 * struct i2c_client - represent an I2C slave device 297 * @flags: see I2C_CLIENT_* for possible flags 298 * @addr: Address used on the I2C bus connected to the parent adapter. 299 * @name: Indicates the type of the device, usually a chip name that's 300 * generic enough to hide second-sourcing and compatible revisions. 301 * @adapter: manages the bus segment hosting this I2C device 302 * @dev: Driver model device node for the slave. 303 * @init_irq: IRQ that was set at initialization 304 * @irq: indicates the IRQ generated by this device (if any) 305 * @detected: member of an i2c_driver.clients list or i2c-core's 306 * userspace_devices list 307 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 308 * calls it to pass on slave events to the slave driver. 309 * 310 * An i2c_client identifies a single device (i.e. chip) connected to an 311 * i2c bus. The behaviour exposed to Linux is defined by the driver 312 * managing the device. 313 */ 314 struct i2c_client { 315 unsigned short flags; /* div., see below */ 316 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 317 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 318 /* Must equal I2C_M_TEN below */ 319 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 320 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 321 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 322 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 323 /* Must match I2C_M_STOP|IGNORE_NAK */ 324 325 unsigned short addr; /* chip address - NOTE: 7bit */ 326 /* addresses are stored in the */ 327 /* _LOWER_ 7 bits */ 328 char name[I2C_NAME_SIZE]; 329 struct i2c_adapter *adapter; /* the adapter we sit on */ 330 struct device dev; /* the device structure */ 331 int init_irq; /* irq set at initialization */ 332 int irq; /* irq issued by device */ 333 struct list_head detected; 334 #if IS_ENABLED(CONFIG_I2C_SLAVE) 335 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 336 #endif 337 }; 338 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 339 340 struct i2c_client *i2c_verify_client(struct device *dev); 341 struct i2c_adapter *i2c_verify_adapter(struct device *dev); 342 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 343 const struct i2c_client *client); 344 345 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 346 { 347 struct device * const dev = kobj_to_dev(kobj); 348 return to_i2c_client(dev); 349 } 350 351 static inline void *i2c_get_clientdata(const struct i2c_client *client) 352 { 353 return dev_get_drvdata(&client->dev); 354 } 355 356 static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 357 { 358 dev_set_drvdata(&client->dev, data); 359 } 360 361 /* I2C slave support */ 362 363 #if IS_ENABLED(CONFIG_I2C_SLAVE) 364 enum i2c_slave_event { 365 I2C_SLAVE_READ_REQUESTED, 366 I2C_SLAVE_WRITE_REQUESTED, 367 I2C_SLAVE_READ_PROCESSED, 368 I2C_SLAVE_WRITE_RECEIVED, 369 I2C_SLAVE_STOP, 370 }; 371 372 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 373 int i2c_slave_unregister(struct i2c_client *client); 374 bool i2c_detect_slave_mode(struct device *dev); 375 376 static inline int i2c_slave_event(struct i2c_client *client, 377 enum i2c_slave_event event, u8 *val) 378 { 379 return client->slave_cb(client, event, val); 380 } 381 #else 382 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 383 #endif 384 385 /** 386 * struct i2c_board_info - template for device creation 387 * @type: chip type, to initialize i2c_client.name 388 * @flags: to initialize i2c_client.flags 389 * @addr: stored in i2c_client.addr 390 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 391 * @platform_data: stored in i2c_client.dev.platform_data 392 * @of_node: pointer to OpenFirmware device node 393 * @fwnode: device node supplied by the platform firmware 394 * @properties: additional device properties for the device 395 * @resources: resources associated with the device 396 * @num_resources: number of resources in the @resources array 397 * @irq: stored in i2c_client.irq 398 * 399 * I2C doesn't actually support hardware probing, although controllers and 400 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 401 * a device at a given address. Drivers commonly need more information than 402 * that, such as chip type, configuration, associated IRQ, and so on. 403 * 404 * i2c_board_info is used to build tables of information listing I2C devices 405 * that are present. This information is used to grow the driver model tree. 406 * For mainboards this is done statically using i2c_register_board_info(); 407 * bus numbers identify adapters that aren't yet available. For add-on boards, 408 * i2c_new_client_device() does this dynamically with the adapter already known. 409 */ 410 struct i2c_board_info { 411 char type[I2C_NAME_SIZE]; 412 unsigned short flags; 413 unsigned short addr; 414 const char *dev_name; 415 void *platform_data; 416 struct device_node *of_node; 417 struct fwnode_handle *fwnode; 418 const struct property_entry *properties; 419 const struct resource *resources; 420 unsigned int num_resources; 421 int irq; 422 }; 423 424 /** 425 * I2C_BOARD_INFO - macro used to list an i2c device and its address 426 * @dev_type: identifies the device type 427 * @dev_addr: the device's address on the bus. 428 * 429 * This macro initializes essential fields of a struct i2c_board_info, 430 * declaring what has been provided on a particular board. Optional 431 * fields (such as associated irq, or device-specific platform_data) 432 * are provided using conventional syntax. 433 */ 434 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 435 .type = dev_type, .addr = (dev_addr) 436 437 438 #if IS_ENABLED(CONFIG_I2C) 439 /* 440 * Add-on boards should register/unregister their devices; e.g. a board 441 * with integrated I2C, a config eeprom, sensors, and a codec that's 442 * used in conjunction with the primary hardware. 443 */ 444 struct i2c_client * 445 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 446 447 /* If you don't know the exact address of an I2C device, use this variant 448 * instead, which can probe for device presence in a list of possible 449 * addresses. The "probe" callback function is optional. If it is provided, 450 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 451 * a default probing method is used. 452 */ 453 struct i2c_client * 454 i2c_new_scanned_device(struct i2c_adapter *adap, 455 struct i2c_board_info *info, 456 unsigned short const *addr_list, 457 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 458 459 /* Common custom probe functions */ 460 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 461 462 struct i2c_client * 463 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 464 465 struct i2c_client * 466 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 467 468 struct i2c_client * 469 i2c_new_ancillary_device(struct i2c_client *client, 470 const char *name, 471 u16 default_addr); 472 473 void i2c_unregister_device(struct i2c_client *client); 474 #endif /* I2C */ 475 476 /* Mainboard arch_initcall() code should register all its I2C devices. 477 * This is done at arch_initcall time, before declaring any i2c adapters. 478 * Modules for add-on boards must use other calls. 479 */ 480 #ifdef CONFIG_I2C_BOARDINFO 481 int 482 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 483 unsigned n); 484 #else 485 static inline int 486 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 487 unsigned n) 488 { 489 return 0; 490 } 491 #endif /* I2C_BOARDINFO */ 492 493 /** 494 * struct i2c_algorithm - represent I2C transfer method 495 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 496 * defined by the msgs array, with num messages available to transfer via 497 * the adapter specified by adap. 498 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 499 * so e.g. PMICs can be accessed very late before shutdown. Optional. 500 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 501 * is not present, then the bus layer will try and convert the SMBus calls 502 * into I2C transfers instead. 503 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 504 * so e.g. PMICs can be accessed very late before shutdown. Optional. 505 * @functionality: Return the flags that this algorithm/adapter pair supports 506 * from the ``I2C_FUNC_*`` flags. 507 * @reg_slave: Register given client to I2C slave mode of this adapter 508 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 509 * 510 * The following structs are for those who like to implement new bus drivers: 511 * i2c_algorithm is the interface to a class of hardware solutions which can 512 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 513 * to name two of the most common. 514 * 515 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 516 * type of error code that occurred during the transfer, as documented in the 517 * Kernel Documentation file Documentation/i2c/fault-codes.rst. 518 */ 519 struct i2c_algorithm { 520 /* 521 * If an adapter algorithm can't do I2C-level access, set master_xfer 522 * to NULL. If an adapter algorithm can do SMBus access, set 523 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 524 * using common I2C messages. 525 * 526 * master_xfer should return the number of messages successfully 527 * processed, or a negative value on error 528 */ 529 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 530 int num); 531 int (*master_xfer_atomic)(struct i2c_adapter *adap, 532 struct i2c_msg *msgs, int num); 533 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 534 unsigned short flags, char read_write, 535 u8 command, int size, union i2c_smbus_data *data); 536 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 537 unsigned short flags, char read_write, 538 u8 command, int size, union i2c_smbus_data *data); 539 540 /* To determine what the adapter supports */ 541 u32 (*functionality)(struct i2c_adapter *adap); 542 543 #if IS_ENABLED(CONFIG_I2C_SLAVE) 544 int (*reg_slave)(struct i2c_client *client); 545 int (*unreg_slave)(struct i2c_client *client); 546 #endif 547 }; 548 549 /** 550 * struct i2c_lock_operations - represent I2C locking operations 551 * @lock_bus: Get exclusive access to an I2C bus segment 552 * @trylock_bus: Try to get exclusive access to an I2C bus segment 553 * @unlock_bus: Release exclusive access to an I2C bus segment 554 * 555 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 556 */ 557 struct i2c_lock_operations { 558 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 559 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 560 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 561 }; 562 563 /** 564 * struct i2c_timings - I2C timing information 565 * @bus_freq_hz: the bus frequency in Hz 566 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 567 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 568 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 569 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 570 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 571 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 572 * digital filter can filter out 573 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 574 * analog filter 575 */ 576 struct i2c_timings { 577 u32 bus_freq_hz; 578 u32 scl_rise_ns; 579 u32 scl_fall_ns; 580 u32 scl_int_delay_ns; 581 u32 sda_fall_ns; 582 u32 sda_hold_ns; 583 u32 digital_filter_width_ns; 584 u32 analog_filter_cutoff_freq_hz; 585 }; 586 587 /** 588 * struct i2c_bus_recovery_info - I2C bus recovery information 589 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 590 * i2c_generic_scl_recovery(). 591 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 592 * recovery. Populated internally for generic GPIO recovery. 593 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 594 * Populated internally for generic GPIO recovery. 595 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 596 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 597 * GPIO, for generic GPIO recovery. 598 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 599 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 600 * for generic GPIO recovery. 601 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 602 * has a more complex internal logic than just reading SDA. Optional. 603 * @prepare_recovery: This will be called before starting recovery. Platform may 604 * configure padmux here for SDA/SCL line or something else they want. 605 * @unprepare_recovery: This will be called after completing recovery. Platform 606 * may configure padmux here for SDA/SCL line or something else they want. 607 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 608 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 609 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 610 * Optional. 611 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 612 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 613 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 614 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 615 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 616 * is called "gpio" or "recovery" and pinctrl is valid. 617 */ 618 struct i2c_bus_recovery_info { 619 int (*recover_bus)(struct i2c_adapter *adap); 620 621 int (*get_scl)(struct i2c_adapter *adap); 622 void (*set_scl)(struct i2c_adapter *adap, int val); 623 int (*get_sda)(struct i2c_adapter *adap); 624 void (*set_sda)(struct i2c_adapter *adap, int val); 625 int (*get_bus_free)(struct i2c_adapter *adap); 626 627 void (*prepare_recovery)(struct i2c_adapter *adap); 628 void (*unprepare_recovery)(struct i2c_adapter *adap); 629 630 /* gpio recovery */ 631 struct gpio_desc *scl_gpiod; 632 struct gpio_desc *sda_gpiod; 633 struct pinctrl *pinctrl; 634 struct pinctrl_state *pins_default; 635 struct pinctrl_state *pins_gpio; 636 }; 637 638 int i2c_recover_bus(struct i2c_adapter *adap); 639 640 /* Generic recovery routines */ 641 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 642 643 /** 644 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 645 * @flags: see I2C_AQ_* for possible flags and read below 646 * @max_num_msgs: maximum number of messages per transfer 647 * @max_write_len: maximum length of a write message 648 * @max_read_len: maximum length of a read message 649 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 650 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 651 * 652 * Note about combined messages: Some I2C controllers can only send one message 653 * per transfer, plus something called combined message or write-then-read. 654 * This is (usually) a small write message followed by a read message and 655 * barely enough to access register based devices like EEPROMs. There is a flag 656 * to support this mode. It implies max_num_msg = 2 and does the length checks 657 * with max_comb_*_len because combined message mode usually has its own 658 * limitations. Because of HW implementations, some controllers can actually do 659 * write-then-anything or other variants. To support that, write-then-read has 660 * been broken out into smaller bits like write-first and read-second which can 661 * be combined as needed. 662 */ 663 664 struct i2c_adapter_quirks { 665 u64 flags; 666 int max_num_msgs; 667 u16 max_write_len; 668 u16 max_read_len; 669 u16 max_comb_1st_msg_len; 670 u16 max_comb_2nd_msg_len; 671 }; 672 673 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 674 #define I2C_AQ_COMB BIT(0) 675 /* first combined message must be write */ 676 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 677 /* second combined message must be read */ 678 #define I2C_AQ_COMB_READ_SECOND BIT(2) 679 /* both combined messages must have the same target address */ 680 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 681 /* convenience macro for typical write-then read case */ 682 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 683 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 684 /* clock stretching is not supported */ 685 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 686 /* message cannot have length of 0 */ 687 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 688 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 689 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 690 691 /* 692 * i2c_adapter is the structure used to identify a physical i2c bus along 693 * with the access algorithms necessary to access it. 694 */ 695 struct i2c_adapter { 696 struct module *owner; 697 unsigned int class; /* classes to allow probing for */ 698 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 699 void *algo_data; 700 701 /* data fields that are valid for all devices */ 702 const struct i2c_lock_operations *lock_ops; 703 struct rt_mutex bus_lock; 704 struct rt_mutex mux_lock; 705 706 int timeout; /* in jiffies */ 707 int retries; 708 struct device dev; /* the adapter device */ 709 unsigned long locked_flags; /* owned by the I2C core */ 710 #define I2C_ALF_IS_SUSPENDED 0 711 #define I2C_ALF_SUSPEND_REPORTED 1 712 713 int nr; 714 char name[48]; 715 struct completion dev_released; 716 717 struct mutex userspace_clients_lock; 718 struct list_head userspace_clients; 719 720 struct i2c_bus_recovery_info *bus_recovery_info; 721 const struct i2c_adapter_quirks *quirks; 722 723 struct irq_domain *host_notify_domain; 724 }; 725 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 726 727 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 728 { 729 return dev_get_drvdata(&adap->dev); 730 } 731 732 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 733 { 734 dev_set_drvdata(&adap->dev, data); 735 } 736 737 static inline struct i2c_adapter * 738 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 739 { 740 #if IS_ENABLED(CONFIG_I2C_MUX) 741 struct device *parent = adapter->dev.parent; 742 743 if (parent != NULL && parent->type == &i2c_adapter_type) 744 return to_i2c_adapter(parent); 745 else 746 #endif 747 return NULL; 748 } 749 750 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 751 752 /* Adapter locking functions, exported for shared pin cases */ 753 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 754 #define I2C_LOCK_SEGMENT BIT(1) 755 756 /** 757 * i2c_lock_bus - Get exclusive access to an I2C bus segment 758 * @adapter: Target I2C bus segment 759 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 760 * locks only this branch in the adapter tree 761 */ 762 static inline void 763 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 764 { 765 adapter->lock_ops->lock_bus(adapter, flags); 766 } 767 768 /** 769 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 770 * @adapter: Target I2C bus segment 771 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 772 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 773 * 774 * Return: true if the I2C bus segment is locked, false otherwise 775 */ 776 static inline int 777 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 778 { 779 return adapter->lock_ops->trylock_bus(adapter, flags); 780 } 781 782 /** 783 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 784 * @adapter: Target I2C bus segment 785 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 786 * unlocks only this branch in the adapter tree 787 */ 788 static inline void 789 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 790 { 791 adapter->lock_ops->unlock_bus(adapter, flags); 792 } 793 794 /** 795 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 796 * @adap: Adapter to mark as suspended 797 * 798 * When using this helper to mark an adapter as suspended, the core will reject 799 * further transfers to this adapter. The usage of this helper is optional but 800 * recommended for devices having distinct handlers for system suspend and 801 * runtime suspend. More complex devices are free to implement custom solutions 802 * to reject transfers when suspended. 803 */ 804 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 805 { 806 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 807 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 808 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 809 } 810 811 /** 812 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 813 * @adap: Adapter to mark as resumed 814 * 815 * When using this helper to mark an adapter as resumed, the core will allow 816 * further transfers to this adapter. See also further notes to 817 * @i2c_mark_adapter_suspended(). 818 */ 819 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 820 { 821 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 822 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 823 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 824 } 825 826 /* i2c adapter classes (bitmask) */ 827 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 828 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 829 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 830 /* Warn users that the adapter doesn't support classes anymore */ 831 #define I2C_CLASS_DEPRECATED (1<<8) 832 833 /* Internal numbers to terminate lists */ 834 #define I2C_CLIENT_END 0xfffeU 835 836 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 837 #define I2C_ADDRS(addr, addrs...) \ 838 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 839 840 841 /* ----- functions exported by i2c.o */ 842 843 /* administration... 844 */ 845 #if IS_ENABLED(CONFIG_I2C) 846 int i2c_add_adapter(struct i2c_adapter *adap); 847 void i2c_del_adapter(struct i2c_adapter *adap); 848 int i2c_add_numbered_adapter(struct i2c_adapter *adap); 849 850 int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 851 void i2c_del_driver(struct i2c_driver *driver); 852 853 /* use a define to avoid include chaining to get THIS_MODULE */ 854 #define i2c_add_driver(driver) \ 855 i2c_register_driver(THIS_MODULE, driver) 856 857 static inline bool i2c_client_has_driver(struct i2c_client *client) 858 { 859 return !IS_ERR_OR_NULL(client) && client->dev.driver; 860 } 861 862 /* call the i2c_client->command() of all attached clients with 863 * the given arguments */ 864 void i2c_clients_command(struct i2c_adapter *adap, 865 unsigned int cmd, void *arg); 866 867 struct i2c_adapter *i2c_get_adapter(int nr); 868 void i2c_put_adapter(struct i2c_adapter *adap); 869 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 870 871 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 872 873 /* Return the functionality mask */ 874 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 875 { 876 return adap->algo->functionality(adap); 877 } 878 879 /* Return 1 if adapter supports everything we need, 0 if not. */ 880 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 881 { 882 return (func & i2c_get_functionality(adap)) == func; 883 } 884 885 /** 886 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 887 * @adap: i2c adapter 888 * @quirks: quirk flags 889 * 890 * Return: true if the adapter has all the specified quirk flags, false if not 891 */ 892 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 893 { 894 if (!adap->quirks) 895 return false; 896 return (adap->quirks->flags & quirks) == quirks; 897 } 898 899 /* Return the adapter number for a specific adapter */ 900 static inline int i2c_adapter_id(struct i2c_adapter *adap) 901 { 902 return adap->nr; 903 } 904 905 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 906 { 907 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 908 } 909 910 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 911 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 912 913 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 914 /** 915 * module_i2c_driver() - Helper macro for registering a modular I2C driver 916 * @__i2c_driver: i2c_driver struct 917 * 918 * Helper macro for I2C drivers which do not do anything special in module 919 * init/exit. This eliminates a lot of boilerplate. Each module may only 920 * use this macro once, and calling it replaces module_init() and module_exit() 921 */ 922 #define module_i2c_driver(__i2c_driver) \ 923 module_driver(__i2c_driver, i2c_add_driver, \ 924 i2c_del_driver) 925 926 /** 927 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 928 * @__i2c_driver: i2c_driver struct 929 * 930 * Helper macro for I2C drivers which do not do anything special in their 931 * init. This eliminates a lot of boilerplate. Each driver may only 932 * use this macro once, and calling it replaces device_initcall(). 933 */ 934 #define builtin_i2c_driver(__i2c_driver) \ 935 builtin_driver(__i2c_driver, i2c_add_driver) 936 937 #endif /* I2C */ 938 939 #if IS_ENABLED(CONFIG_OF) 940 /* must call put_device() when done with returned i2c_client device */ 941 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 942 943 /* must call put_device() when done with returned i2c_adapter device */ 944 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 945 946 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 947 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 948 949 const struct of_device_id 950 *i2c_of_match_device(const struct of_device_id *matches, 951 struct i2c_client *client); 952 953 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 954 struct i2c_board_info *info); 955 956 #else 957 958 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 959 { 960 return NULL; 961 } 962 963 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 964 { 965 return NULL; 966 } 967 968 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 969 { 970 return NULL; 971 } 972 973 static inline const struct of_device_id 974 *i2c_of_match_device(const struct of_device_id *matches, 975 struct i2c_client *client) 976 { 977 return NULL; 978 } 979 980 static inline int of_i2c_get_board_info(struct device *dev, 981 struct device_node *node, 982 struct i2c_board_info *info) 983 { 984 return -ENOTSUPP; 985 } 986 987 #endif /* CONFIG_OF */ 988 989 struct acpi_resource; 990 struct acpi_resource_i2c_serialbus; 991 992 #if IS_ENABLED(CONFIG_ACPI) 993 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 994 struct acpi_resource_i2c_serialbus **i2c); 995 u32 i2c_acpi_find_bus_speed(struct device *dev); 996 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 997 struct i2c_board_info *info); 998 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 999 #else 1000 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1001 struct acpi_resource_i2c_serialbus **i2c) 1002 { 1003 return false; 1004 } 1005 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1006 { 1007 return 0; 1008 } 1009 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1010 int index, struct i2c_board_info *info) 1011 { 1012 return ERR_PTR(-ENODEV); 1013 } 1014 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1015 { 1016 return NULL; 1017 } 1018 #endif /* CONFIG_ACPI */ 1019 1020 #endif /* _LINUX_I2C_H */ 1021