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@the-dreams.de> 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 struct module; 43 struct property_entry; 44 45 #if IS_ENABLED(CONFIG_I2C) 46 /* 47 * The master routines are the ones normally used to transmit data to devices 48 * on a bus (or read from them). Apart from two basic transfer functions to 49 * transmit one message at a time, a more complex version can be used to 50 * transmit an arbitrary number of messages without interruption. 51 * @count must be be less than 64k since msg.len is u16. 52 */ 53 int i2c_transfer_buffer_flags(const struct i2c_client *client, 54 char *buf, int count, u16 flags); 55 56 /** 57 * i2c_master_recv - issue a single I2C message in master receive mode 58 * @client: Handle to slave device 59 * @buf: Where to store data read from slave 60 * @count: How many bytes to read, must be less than 64k since msg.len is u16 61 * 62 * Returns negative errno, or else the number of bytes read. 63 */ 64 static inline int i2c_master_recv(const struct i2c_client *client, 65 char *buf, int count) 66 { 67 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 68 }; 69 70 /** 71 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 72 * using a DMA safe buffer 73 * @client: Handle to slave device 74 * @buf: Where to store data read from slave, must be safe to use with DMA 75 * @count: How many bytes to read, must be less than 64k since msg.len is u16 76 * 77 * Returns negative errno, or else the number of bytes read. 78 */ 79 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 80 char *buf, int count) 81 { 82 return i2c_transfer_buffer_flags(client, buf, count, 83 I2C_M_RD | I2C_M_DMA_SAFE); 84 }; 85 86 /** 87 * i2c_master_send - issue a single I2C message in master transmit mode 88 * @client: Handle to slave device 89 * @buf: Data that will be written to the slave 90 * @count: How many bytes to write, must be less than 64k since msg.len is u16 91 * 92 * Returns negative errno, or else the number of bytes written. 93 */ 94 static inline int i2c_master_send(const struct i2c_client *client, 95 const char *buf, int count) 96 { 97 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 98 }; 99 100 /** 101 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 102 * using a DMA safe buffer 103 * @client: Handle to slave device 104 * @buf: Data that will be written to the slave, must be safe to use with DMA 105 * @count: How many bytes to write, must be less than 64k since msg.len is u16 106 * 107 * Returns negative errno, or else the number of bytes written. 108 */ 109 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 110 const char *buf, int count) 111 { 112 return i2c_transfer_buffer_flags(client, (char *)buf, count, 113 I2C_M_DMA_SAFE); 114 }; 115 116 /* Transfer num messages. 117 */ 118 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 119 /* Unlocked flavor */ 120 int __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. */ 127 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 128 unsigned short flags, char read_write, u8 command, 129 int protocol, union i2c_smbus_data *data); 130 131 /* Unlocked flavor */ 132 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 133 unsigned short flags, char read_write, u8 command, 134 int protocol, union i2c_smbus_data *data); 135 136 /* Now follow the 'nice' access routines. These also document the calling 137 conventions of i2c_smbus_xfer. */ 138 139 s32 i2c_smbus_read_byte(const struct i2c_client *client); 140 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 141 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 142 s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 143 u8 command, u8 value); 144 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 145 s32 i2c_smbus_write_word_data(const struct i2c_client *client, 146 u8 command, u16 value); 147 148 static inline s32 149 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 150 { 151 s32 value = i2c_smbus_read_word_data(client, command); 152 153 return (value < 0) ? value : swab16(value); 154 } 155 156 static inline s32 157 i2c_smbus_write_word_swapped(const struct i2c_client *client, 158 u8 command, u16 value) 159 { 160 return i2c_smbus_write_word_data(client, command, swab16(value)); 161 } 162 163 /* Returns the number of read bytes */ 164 s32 i2c_smbus_read_block_data(const struct i2c_client *client, 165 u8 command, u8 *values); 166 s32 i2c_smbus_write_block_data(const struct i2c_client *client, 167 u8 command, u8 length, const u8 *values); 168 /* Returns the number of read bytes */ 169 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 170 u8 command, u8 length, u8 *values); 171 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 172 u8 command, u8 length, const u8 *values); 173 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 174 u8 command, u8 length, 175 u8 *values); 176 int i2c_get_device_id(const struct i2c_client *client, 177 struct i2c_device_identity *id); 178 #endif /* I2C */ 179 180 /** 181 * struct i2c_device_identity - i2c client device identification 182 * @manufacturer_id: 0 - 4095, database maintained by NXP 183 * @part_id: 0 - 511, according to manufacturer 184 * @die_revision: 0 - 7, according to manufacturer 185 */ 186 struct i2c_device_identity { 187 u16 manufacturer_id; 188 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 189 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 190 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 191 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 192 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 193 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 194 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 195 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 196 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 197 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 198 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 199 #define I2C_DEVICE_ID_FLIR 11 200 #define I2C_DEVICE_ID_O2MICRO 12 201 #define I2C_DEVICE_ID_ATMEL 13 202 #define I2C_DEVICE_ID_NONE 0xffff 203 u16 part_id; 204 u8 die_revision; 205 }; 206 207 enum i2c_alert_protocol { 208 I2C_PROTOCOL_SMBUS_ALERT, 209 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 210 }; 211 212 /** 213 * struct i2c_driver - represent an I2C device driver 214 * @class: What kind of i2c device we instantiate (for detect) 215 * @probe: Callback for device binding - soon to be deprecated 216 * @probe_new: New callback for device binding 217 * @remove: Callback for device unbinding 218 * @shutdown: Callback for device shutdown 219 * @alert: Alert callback, for example for the SMBus alert protocol 220 * @command: Callback for bus-wide signaling (optional) 221 * @driver: Device driver model driver 222 * @id_table: List of I2C devices supported by this driver 223 * @detect: Callback for device detection 224 * @address_list: The I2C addresses to probe (for detect) 225 * @clients: List of detected clients we created (for i2c-core use only) 226 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 227 * 228 * The driver.owner field should be set to the module owner of this driver. 229 * The driver.name field should be set to the name of this driver. 230 * 231 * For automatic device detection, both @detect and @address_list must 232 * be defined. @class should also be set, otherwise only devices forced 233 * with module parameters will be created. The detect function must 234 * fill at least the name field of the i2c_board_info structure it is 235 * handed upon successful detection, and possibly also the flags field. 236 * 237 * If @detect is missing, the driver will still work fine for enumerated 238 * devices. Detected devices simply won't be supported. This is expected 239 * for the many I2C/SMBus devices which can't be detected reliably, and 240 * the ones which can always be enumerated in practice. 241 * 242 * The i2c_client structure which is handed to the @detect callback is 243 * not a real i2c_client. It is initialized just enough so that you can 244 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 245 * else with it. In particular, calling dev_dbg and friends on it is 246 * not allowed. 247 */ 248 struct i2c_driver { 249 unsigned int class; 250 251 /* Standard driver model interfaces */ 252 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id); 253 int (*remove)(struct i2c_client *client); 254 255 /* New driver model interface to aid the seamless removal of the 256 * current probe()'s, more commonly unused than used second parameter. 257 */ 258 int (*probe_new)(struct i2c_client *client); 259 260 /* driver model interfaces that don't relate to enumeration */ 261 void (*shutdown)(struct i2c_client *client); 262 263 /* Alert callback, for example for the SMBus alert protocol. 264 * The format and meaning of the data value depends on the protocol. 265 * For the SMBus alert protocol, there is a single bit of data passed 266 * as the alert response's low bit ("event flag"). 267 * For the SMBus Host Notify protocol, the data corresponds to the 268 * 16-bit payload data reported by the slave device acting as master. 269 */ 270 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 271 unsigned int data); 272 273 /* a ioctl like command that can be used to perform specific functions 274 * with the device. 275 */ 276 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 277 278 struct device_driver driver; 279 const struct i2c_device_id *id_table; 280 281 /* Device detection callback for automatic device creation */ 282 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 283 const unsigned short *address_list; 284 struct list_head clients; 285 286 bool disable_i2c_core_irq_mapping; 287 }; 288 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 289 290 /** 291 * struct i2c_client - represent an I2C slave device 292 * @flags: see I2C_CLIENT_* for possible flags 293 * @addr: Address used on the I2C bus connected to the parent adapter. 294 * @name: Indicates the type of the device, usually a chip name that's 295 * generic enough to hide second-sourcing and compatible revisions. 296 * @adapter: manages the bus segment hosting this I2C device 297 * @dev: Driver model device node for the slave. 298 * @init_irq: IRQ that was set at initialization 299 * @irq: indicates the IRQ generated by this device (if any) 300 * @detected: member of an i2c_driver.clients list or i2c-core's 301 * userspace_devices list 302 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 303 * calls it to pass on slave events to the slave driver. 304 * 305 * An i2c_client identifies a single device (i.e. chip) connected to an 306 * i2c bus. The behaviour exposed to Linux is defined by the driver 307 * managing the device. 308 */ 309 struct i2c_client { 310 unsigned short flags; /* div., see below */ 311 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 312 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 313 /* Must equal I2C_M_TEN below */ 314 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 315 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 316 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 317 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 318 /* Must match I2C_M_STOP|IGNORE_NAK */ 319 320 unsigned short addr; /* chip address - NOTE: 7bit */ 321 /* addresses are stored in the */ 322 /* _LOWER_ 7 bits */ 323 char name[I2C_NAME_SIZE]; 324 struct i2c_adapter *adapter; /* the adapter we sit on */ 325 struct device dev; /* the device structure */ 326 int init_irq; /* irq set at initialization */ 327 int irq; /* irq issued by device */ 328 struct list_head detected; 329 #if IS_ENABLED(CONFIG_I2C_SLAVE) 330 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 331 #endif 332 }; 333 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 334 335 struct i2c_client *i2c_verify_client(struct device *dev); 336 struct i2c_adapter *i2c_verify_adapter(struct device *dev); 337 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 338 const struct i2c_client *client); 339 340 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 341 { 342 struct device * const dev = container_of(kobj, struct device, kobj); 343 return to_i2c_client(dev); 344 } 345 346 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 347 { 348 return dev_get_drvdata(&dev->dev); 349 } 350 351 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 352 { 353 dev_set_drvdata(&dev->dev, data); 354 } 355 356 /* I2C slave support */ 357 358 #if IS_ENABLED(CONFIG_I2C_SLAVE) 359 enum i2c_slave_event { 360 I2C_SLAVE_READ_REQUESTED, 361 I2C_SLAVE_WRITE_REQUESTED, 362 I2C_SLAVE_READ_PROCESSED, 363 I2C_SLAVE_WRITE_RECEIVED, 364 I2C_SLAVE_STOP, 365 }; 366 367 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 368 int i2c_slave_unregister(struct i2c_client *client); 369 bool i2c_detect_slave_mode(struct device *dev); 370 371 static inline int i2c_slave_event(struct i2c_client *client, 372 enum i2c_slave_event event, u8 *val) 373 { 374 return client->slave_cb(client, event, val); 375 } 376 #else 377 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 378 #endif 379 380 /** 381 * struct i2c_board_info - template for device creation 382 * @type: chip type, to initialize i2c_client.name 383 * @flags: to initialize i2c_client.flags 384 * @addr: stored in i2c_client.addr 385 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 386 * @platform_data: stored in i2c_client.dev.platform_data 387 * @of_node: pointer to OpenFirmware device node 388 * @fwnode: device node supplied by the platform firmware 389 * @properties: additional device properties for the device 390 * @resources: resources associated with the device 391 * @num_resources: number of resources in the @resources array 392 * @irq: stored in i2c_client.irq 393 * 394 * I2C doesn't actually support hardware probing, although controllers and 395 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 396 * a device at a given address. Drivers commonly need more information than 397 * that, such as chip type, configuration, associated IRQ, and so on. 398 * 399 * i2c_board_info is used to build tables of information listing I2C devices 400 * that are present. This information is used to grow the driver model tree. 401 * For mainboards this is done statically using i2c_register_board_info(); 402 * bus numbers identify adapters that aren't yet available. For add-on boards, 403 * i2c_new_device() does this dynamically with the adapter already known. 404 */ 405 struct i2c_board_info { 406 char type[I2C_NAME_SIZE]; 407 unsigned short flags; 408 unsigned short addr; 409 const char *dev_name; 410 void *platform_data; 411 struct device_node *of_node; 412 struct fwnode_handle *fwnode; 413 const struct property_entry *properties; 414 const struct resource *resources; 415 unsigned int num_resources; 416 int irq; 417 }; 418 419 /** 420 * I2C_BOARD_INFO - macro used to list an i2c device and its address 421 * @dev_type: identifies the device type 422 * @dev_addr: the device's address on the bus. 423 * 424 * This macro initializes essential fields of a struct i2c_board_info, 425 * declaring what has been provided on a particular board. Optional 426 * fields (such as associated irq, or device-specific platform_data) 427 * are provided using conventional syntax. 428 */ 429 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 430 .type = dev_type, .addr = (dev_addr) 431 432 433 #if IS_ENABLED(CONFIG_I2C) 434 /* Add-on boards should register/unregister their devices; e.g. a board 435 * with integrated I2C, a config eeprom, sensors, and a codec that's 436 * used in conjunction with the primary hardware. 437 */ 438 struct i2c_client * 439 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 440 441 struct i2c_client * 442 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 443 444 /* If you don't know the exact address of an I2C device, use this variant 445 * instead, which can probe for device presence in a list of possible 446 * addresses. The "probe" callback function is optional. If it is provided, 447 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 448 * a default probing method is used. 449 */ 450 struct i2c_client * 451 i2c_new_scanned_device(struct i2c_adapter *adap, 452 struct i2c_board_info *info, 453 unsigned short const *addr_list, 454 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 455 456 struct i2c_client * 457 i2c_new_probed_device(struct i2c_adapter *adap, 458 struct i2c_board_info *info, 459 unsigned short const *addr_list, 460 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 461 462 /* Common custom probe functions */ 463 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 464 465 struct i2c_client * 466 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 467 468 struct i2c_client * 469 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 470 471 struct i2c_client * 472 i2c_new_ancillary_device(struct i2c_client *client, 473 const char *name, 474 u16 default_addr); 475 476 void i2c_unregister_device(struct i2c_client *client); 477 #endif /* I2C */ 478 479 /* Mainboard arch_initcall() code should register all its I2C devices. 480 * This is done at arch_initcall time, before declaring any i2c adapters. 481 * Modules for add-on boards must use other calls. 482 */ 483 #ifdef CONFIG_I2C_BOARDINFO 484 int 485 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 486 unsigned n); 487 #else 488 static inline int 489 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 490 unsigned n) 491 { 492 return 0; 493 } 494 #endif /* I2C_BOARDINFO */ 495 496 /** 497 * struct i2c_algorithm - represent I2C transfer method 498 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 499 * defined by the msgs array, with num messages available to transfer via 500 * the adapter specified by adap. 501 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 502 * so e.g. PMICs can be accessed very late before shutdown. Optional. 503 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 504 * is not present, then the bus layer will try and convert the SMBus calls 505 * into I2C transfers instead. 506 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 507 * so e.g. PMICs can be accessed very late before shutdown. Optional. 508 * @functionality: Return the flags that this algorithm/adapter pair supports 509 * from the ``I2C_FUNC_*`` flags. 510 * @reg_slave: Register given client to I2C slave mode of this adapter 511 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 512 * 513 * The following structs are for those who like to implement new bus drivers: 514 * i2c_algorithm is the interface to a class of hardware solutions which can 515 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 516 * to name two of the most common. 517 * 518 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 519 * type of error code that occurred during the transfer, as documented in the 520 * Kernel Documentation file Documentation/i2c/fault-codes.rst. 521 */ 522 struct i2c_algorithm { 523 /* 524 * If an adapter algorithm can't do I2C-level access, set master_xfer 525 * to NULL. If an adapter algorithm can do SMBus access, set 526 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 527 * using common I2C messages. 528 * 529 * master_xfer should return the number of messages successfully 530 * processed, or a negative value on error 531 */ 532 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 533 int num); 534 int (*master_xfer_atomic)(struct i2c_adapter *adap, 535 struct i2c_msg *msgs, int num); 536 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 537 unsigned short flags, char read_write, 538 u8 command, int size, union i2c_smbus_data *data); 539 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 540 unsigned short flags, char read_write, 541 u8 command, int size, union i2c_smbus_data *data); 542 543 /* To determine what the adapter supports */ 544 u32 (*functionality)(struct i2c_adapter *adap); 545 546 #if IS_ENABLED(CONFIG_I2C_SLAVE) 547 int (*reg_slave)(struct i2c_client *client); 548 int (*unreg_slave)(struct i2c_client *client); 549 #endif 550 }; 551 552 /** 553 * struct i2c_lock_operations - represent I2C locking operations 554 * @lock_bus: Get exclusive access to an I2C bus segment 555 * @trylock_bus: Try to get exclusive access to an I2C bus segment 556 * @unlock_bus: Release exclusive access to an I2C bus segment 557 * 558 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 559 */ 560 struct i2c_lock_operations { 561 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 562 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 563 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 564 }; 565 566 /** 567 * struct i2c_timings - I2C timing information 568 * @bus_freq_hz: the bus frequency in Hz 569 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 570 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 571 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 572 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 573 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 574 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 575 * digital filter can filter out 576 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 577 * analog filter 578 */ 579 struct i2c_timings { 580 u32 bus_freq_hz; 581 u32 scl_rise_ns; 582 u32 scl_fall_ns; 583 u32 scl_int_delay_ns; 584 u32 sda_fall_ns; 585 u32 sda_hold_ns; 586 u32 digital_filter_width_ns; 587 u32 analog_filter_cutoff_freq_hz; 588 }; 589 590 /** 591 * struct i2c_bus_recovery_info - I2C bus recovery information 592 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 593 * i2c_generic_scl_recovery(). 594 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 595 * recovery. Populated internally for generic GPIO recovery. 596 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 597 * Populated internally for generic GPIO recovery. 598 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 599 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 600 * GPIO, for generic GPIO recovery. 601 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 602 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 603 * for generic GPIO recovery. 604 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 605 * has a more complex internal logic than just reading SDA. Optional. 606 * @prepare_recovery: This will be called before starting recovery. Platform may 607 * configure padmux here for SDA/SCL line or something else they want. 608 * @unprepare_recovery: This will be called after completing recovery. Platform 609 * may configure padmux here for SDA/SCL line or something else they want. 610 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 611 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 612 */ 613 struct i2c_bus_recovery_info { 614 int (*recover_bus)(struct i2c_adapter *adap); 615 616 int (*get_scl)(struct i2c_adapter *adap); 617 void (*set_scl)(struct i2c_adapter *adap, int val); 618 int (*get_sda)(struct i2c_adapter *adap); 619 void (*set_sda)(struct i2c_adapter *adap, int val); 620 int (*get_bus_free)(struct i2c_adapter *adap); 621 622 void (*prepare_recovery)(struct i2c_adapter *adap); 623 void (*unprepare_recovery)(struct i2c_adapter *adap); 624 625 /* gpio recovery */ 626 struct gpio_desc *scl_gpiod; 627 struct gpio_desc *sda_gpiod; 628 }; 629 630 int i2c_recover_bus(struct i2c_adapter *adap); 631 632 /* Generic recovery routines */ 633 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 634 635 /** 636 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 637 * @flags: see I2C_AQ_* for possible flags and read below 638 * @max_num_msgs: maximum number of messages per transfer 639 * @max_write_len: maximum length of a write message 640 * @max_read_len: maximum length of a read message 641 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 642 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 643 * 644 * Note about combined messages: Some I2C controllers can only send one message 645 * per transfer, plus something called combined message or write-then-read. 646 * This is (usually) a small write message followed by a read message and 647 * barely enough to access register based devices like EEPROMs. There is a flag 648 * to support this mode. It implies max_num_msg = 2 and does the length checks 649 * with max_comb_*_len because combined message mode usually has its own 650 * limitations. Because of HW implementations, some controllers can actually do 651 * write-then-anything or other variants. To support that, write-then-read has 652 * been broken out into smaller bits like write-first and read-second which can 653 * be combined as needed. 654 */ 655 656 struct i2c_adapter_quirks { 657 u64 flags; 658 int max_num_msgs; 659 u16 max_write_len; 660 u16 max_read_len; 661 u16 max_comb_1st_msg_len; 662 u16 max_comb_2nd_msg_len; 663 }; 664 665 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 666 #define I2C_AQ_COMB BIT(0) 667 /* first combined message must be write */ 668 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 669 /* second combined message must be read */ 670 #define I2C_AQ_COMB_READ_SECOND BIT(2) 671 /* both combined messages must have the same target address */ 672 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 673 /* convenience macro for typical write-then read case */ 674 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 675 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 676 /* clock stretching is not supported */ 677 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 678 /* message cannot have length of 0 */ 679 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 680 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 681 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 682 683 /* 684 * i2c_adapter is the structure used to identify a physical i2c bus along 685 * with the access algorithms necessary to access it. 686 */ 687 struct i2c_adapter { 688 struct module *owner; 689 unsigned int class; /* classes to allow probing for */ 690 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 691 void *algo_data; 692 693 /* data fields that are valid for all devices */ 694 const struct i2c_lock_operations *lock_ops; 695 struct rt_mutex bus_lock; 696 struct rt_mutex mux_lock; 697 698 int timeout; /* in jiffies */ 699 int retries; 700 struct device dev; /* the adapter device */ 701 unsigned long locked_flags; /* owned by the I2C core */ 702 #define I2C_ALF_IS_SUSPENDED 0 703 #define I2C_ALF_SUSPEND_REPORTED 1 704 705 int nr; 706 char name[48]; 707 struct completion dev_released; 708 709 struct mutex userspace_clients_lock; 710 struct list_head userspace_clients; 711 712 struct i2c_bus_recovery_info *bus_recovery_info; 713 const struct i2c_adapter_quirks *quirks; 714 715 struct irq_domain *host_notify_domain; 716 }; 717 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 718 719 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 720 { 721 return dev_get_drvdata(&adap->dev); 722 } 723 724 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 725 { 726 dev_set_drvdata(&adap->dev, data); 727 } 728 729 static inline struct i2c_adapter * 730 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 731 { 732 #if IS_ENABLED(CONFIG_I2C_MUX) 733 struct device *parent = adapter->dev.parent; 734 735 if (parent != NULL && parent->type == &i2c_adapter_type) 736 return to_i2c_adapter(parent); 737 else 738 #endif 739 return NULL; 740 } 741 742 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 743 744 /* Adapter locking functions, exported for shared pin cases */ 745 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 746 #define I2C_LOCK_SEGMENT BIT(1) 747 748 /** 749 * i2c_lock_bus - Get exclusive access to an I2C bus segment 750 * @adapter: Target I2C bus segment 751 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 752 * locks only this branch in the adapter tree 753 */ 754 static inline void 755 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 756 { 757 adapter->lock_ops->lock_bus(adapter, flags); 758 } 759 760 /** 761 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 762 * @adapter: Target I2C bus segment 763 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 764 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 765 * 766 * Return: true if the I2C bus segment is locked, false otherwise 767 */ 768 static inline int 769 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 770 { 771 return adapter->lock_ops->trylock_bus(adapter, flags); 772 } 773 774 /** 775 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 776 * @adapter: Target I2C bus segment 777 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 778 * unlocks only this branch in the adapter tree 779 */ 780 static inline void 781 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 782 { 783 adapter->lock_ops->unlock_bus(adapter, flags); 784 } 785 786 /** 787 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 788 * @adap: Adapter to mark as suspended 789 * 790 * When using this helper to mark an adapter as suspended, the core will reject 791 * further transfers to this adapter. The usage of this helper is optional but 792 * recommended for devices having distinct handlers for system suspend and 793 * runtime suspend. More complex devices are free to implement custom solutions 794 * to reject transfers when suspended. 795 */ 796 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 797 { 798 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 799 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 800 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 801 } 802 803 /** 804 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 805 * @adap: Adapter to mark as resumed 806 * 807 * When using this helper to mark an adapter as resumed, the core will allow 808 * further transfers to this adapter. See also further notes to 809 * @i2c_mark_adapter_suspended(). 810 */ 811 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 812 { 813 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 814 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 815 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 816 } 817 818 /* i2c adapter classes (bitmask) */ 819 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 820 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 821 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 822 /* Warn users that the adapter doesn't support classes anymore */ 823 #define I2C_CLASS_DEPRECATED (1<<8) 824 825 /* Internal numbers to terminate lists */ 826 #define I2C_CLIENT_END 0xfffeU 827 828 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 829 #define I2C_ADDRS(addr, addrs...) \ 830 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 831 832 833 /* ----- functions exported by i2c.o */ 834 835 /* administration... 836 */ 837 #if IS_ENABLED(CONFIG_I2C) 838 int i2c_add_adapter(struct i2c_adapter *adap); 839 void i2c_del_adapter(struct i2c_adapter *adap); 840 int i2c_add_numbered_adapter(struct i2c_adapter *adap); 841 842 int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 843 void i2c_del_driver(struct i2c_driver *driver); 844 845 /* use a define to avoid include chaining to get THIS_MODULE */ 846 #define i2c_add_driver(driver) \ 847 i2c_register_driver(THIS_MODULE, driver) 848 849 static inline bool i2c_client_has_driver(struct i2c_client *client) 850 { 851 return !IS_ERR_OR_NULL(client) && client->dev.driver; 852 } 853 854 /* call the i2c_client->command() of all attached clients with 855 * the given arguments */ 856 void i2c_clients_command(struct i2c_adapter *adap, 857 unsigned int cmd, void *arg); 858 859 struct i2c_adapter *i2c_get_adapter(int nr); 860 void i2c_put_adapter(struct i2c_adapter *adap); 861 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 862 863 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 864 865 /* Return the functionality mask */ 866 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 867 { 868 return adap->algo->functionality(adap); 869 } 870 871 /* Return 1 if adapter supports everything we need, 0 if not. */ 872 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 873 { 874 return (func & i2c_get_functionality(adap)) == func; 875 } 876 877 /** 878 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 879 * @adap: i2c adapter 880 * @quirks: quirk flags 881 * 882 * Return: true if the adapter has all the specified quirk flags, false if not 883 */ 884 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 885 { 886 if (!adap->quirks) 887 return false; 888 return (adap->quirks->flags & quirks) == quirks; 889 } 890 891 /* Return the adapter number for a specific adapter */ 892 static inline int i2c_adapter_id(struct i2c_adapter *adap) 893 { 894 return adap->nr; 895 } 896 897 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 898 { 899 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 900 } 901 902 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 903 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 904 905 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 906 /** 907 * module_i2c_driver() - Helper macro for registering a modular I2C driver 908 * @__i2c_driver: i2c_driver struct 909 * 910 * Helper macro for I2C drivers which do not do anything special in module 911 * init/exit. This eliminates a lot of boilerplate. Each module may only 912 * use this macro once, and calling it replaces module_init() and module_exit() 913 */ 914 #define module_i2c_driver(__i2c_driver) \ 915 module_driver(__i2c_driver, i2c_add_driver, \ 916 i2c_del_driver) 917 918 /** 919 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 920 * @__i2c_driver: i2c_driver struct 921 * 922 * Helper macro for I2C drivers which do not do anything special in their 923 * init. This eliminates a lot of boilerplate. Each driver may only 924 * use this macro once, and calling it replaces device_initcall(). 925 */ 926 #define builtin_i2c_driver(__i2c_driver) \ 927 builtin_driver(__i2c_driver, i2c_add_driver) 928 929 #endif /* I2C */ 930 931 #if IS_ENABLED(CONFIG_OF) 932 /* must call put_device() when done with returned i2c_client device */ 933 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 934 935 /* must call put_device() when done with returned i2c_adapter device */ 936 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 937 938 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 939 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 940 941 const struct of_device_id 942 *i2c_of_match_device(const struct of_device_id *matches, 943 struct i2c_client *client); 944 945 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 946 struct i2c_board_info *info); 947 948 #else 949 950 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 951 { 952 return NULL; 953 } 954 955 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 956 { 957 return NULL; 958 } 959 960 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 961 { 962 return NULL; 963 } 964 965 static inline const struct of_device_id 966 *i2c_of_match_device(const struct of_device_id *matches, 967 struct i2c_client *client) 968 { 969 return NULL; 970 } 971 972 static inline int of_i2c_get_board_info(struct device *dev, 973 struct device_node *node, 974 struct i2c_board_info *info) 975 { 976 return -ENOTSUPP; 977 } 978 979 #endif /* CONFIG_OF */ 980 981 struct acpi_resource; 982 struct acpi_resource_i2c_serialbus; 983 984 #if IS_ENABLED(CONFIG_ACPI) 985 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 986 struct acpi_resource_i2c_serialbus **i2c); 987 u32 i2c_acpi_find_bus_speed(struct device *dev); 988 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 989 struct i2c_board_info *info); 990 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 991 #else 992 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 993 struct acpi_resource_i2c_serialbus **i2c) 994 { 995 return false; 996 } 997 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 998 { 999 return 0; 1000 } 1001 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1002 int index, struct i2c_board_info *info) 1003 { 1004 return NULL; 1005 } 1006 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1007 { 1008 return NULL; 1009 } 1010 #endif /* CONFIG_ACPI */ 1011 1012 #endif /* _LINUX_I2C_H */ 1013