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 extern 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 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 119 int num); 120 /* Unlocked flavor */ 121 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 122 int num); 123 124 /* This is the very generalized SMBus access routine. You probably do not 125 want to use this, though; one of the functions below may be much easier, 126 and probably just as fast. 127 Note that we use i2c_adapter here, because you do not need a specific 128 smbus adapter to call this function. */ 129 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 130 unsigned short flags, char read_write, u8 command, 131 int protocol, union i2c_smbus_data *data); 132 133 /* Unlocked flavor */ 134 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 135 unsigned short flags, char read_write, u8 command, 136 int protocol, union i2c_smbus_data *data); 137 138 /* Now follow the 'nice' access routines. These also document the calling 139 conventions of i2c_smbus_xfer. */ 140 141 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 142 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 143 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 144 u8 command); 145 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 146 u8 command, u8 value); 147 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 148 u8 command); 149 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 150 u8 command, u16 value); 151 152 static inline s32 153 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 154 { 155 s32 value = i2c_smbus_read_word_data(client, command); 156 157 return (value < 0) ? value : swab16(value); 158 } 159 160 static inline s32 161 i2c_smbus_write_word_swapped(const struct i2c_client *client, 162 u8 command, u16 value) 163 { 164 return i2c_smbus_write_word_data(client, command, swab16(value)); 165 } 166 167 /* Returns the number of read bytes */ 168 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 169 u8 command, u8 *values); 170 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 171 u8 command, u8 length, const u8 *values); 172 /* Returns the number of read bytes */ 173 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 174 u8 command, u8 length, u8 *values); 175 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 176 u8 command, u8 length, 177 const u8 *values); 178 extern s32 179 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 180 u8 command, u8 length, u8 *values); 181 int i2c_get_device_id(const struct i2c_client *client, 182 struct i2c_device_identity *id); 183 #endif /* I2C */ 184 185 /** 186 * struct i2c_device_identity - i2c client device identification 187 * @manufacturer_id: 0 - 4095, database maintained by NXP 188 * @part_id: 0 - 511, according to manufacturer 189 * @die_revision: 0 - 7, according to manufacturer 190 */ 191 struct i2c_device_identity { 192 u16 manufacturer_id; 193 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 194 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 195 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 196 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 197 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 198 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 199 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 200 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 201 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 202 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 203 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 204 #define I2C_DEVICE_ID_FLIR 11 205 #define I2C_DEVICE_ID_O2MICRO 12 206 #define I2C_DEVICE_ID_ATMEL 13 207 #define I2C_DEVICE_ID_NONE 0xffff 208 u16 part_id; 209 u8 die_revision; 210 }; 211 212 enum i2c_alert_protocol { 213 I2C_PROTOCOL_SMBUS_ALERT, 214 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 215 }; 216 217 /** 218 * struct i2c_driver - represent an I2C device driver 219 * @class: What kind of i2c device we instantiate (for detect) 220 * @probe: Callback for device binding - soon to be deprecated 221 * @probe_new: New callback for device binding 222 * @remove: Callback for device unbinding 223 * @shutdown: Callback for device shutdown 224 * @alert: Alert callback, for example for the SMBus alert protocol 225 * @command: Callback for bus-wide signaling (optional) 226 * @driver: Device driver model driver 227 * @id_table: List of I2C devices supported by this driver 228 * @detect: Callback for device detection 229 * @address_list: The I2C addresses to probe (for detect) 230 * @clients: List of detected clients we created (for i2c-core use only) 231 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 232 * 233 * The driver.owner field should be set to the module owner of this driver. 234 * The driver.name field should be set to the name of this driver. 235 * 236 * For automatic device detection, both @detect and @address_list must 237 * be defined. @class should also be set, otherwise only devices forced 238 * with module parameters will be created. The detect function must 239 * fill at least the name field of the i2c_board_info structure it is 240 * handed upon successful detection, and possibly also the flags field. 241 * 242 * If @detect is missing, the driver will still work fine for enumerated 243 * devices. Detected devices simply won't be supported. This is expected 244 * for the many I2C/SMBus devices which can't be detected reliably, and 245 * the ones which can always be enumerated in practice. 246 * 247 * The i2c_client structure which is handed to the @detect callback is 248 * not a real i2c_client. It is initialized just enough so that you can 249 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 250 * else with it. In particular, calling dev_dbg and friends on it is 251 * not allowed. 252 */ 253 struct i2c_driver { 254 unsigned int class; 255 256 /* Standard driver model interfaces */ 257 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id); 258 int (*remove)(struct i2c_client *client); 259 260 /* New driver model interface to aid the seamless removal of the 261 * current probe()'s, more commonly unused than used second parameter. 262 */ 263 int (*probe_new)(struct i2c_client *client); 264 265 /* driver model interfaces that don't relate to enumeration */ 266 void (*shutdown)(struct i2c_client *client); 267 268 /* Alert callback, for example for the SMBus alert protocol. 269 * The format and meaning of the data value depends on the protocol. 270 * For the SMBus alert protocol, there is a single bit of data passed 271 * as the alert response's low bit ("event flag"). 272 * For the SMBus Host Notify protocol, the data corresponds to the 273 * 16-bit payload data reported by the slave device acting as master. 274 */ 275 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 276 unsigned int data); 277 278 /* a ioctl like command that can be used to perform specific functions 279 * with the device. 280 */ 281 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 282 283 struct device_driver driver; 284 const struct i2c_device_id *id_table; 285 286 /* Device detection callback for automatic device creation */ 287 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 288 const unsigned short *address_list; 289 struct list_head clients; 290 291 bool disable_i2c_core_irq_mapping; 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 extern struct i2c_client *i2c_verify_client(struct device *dev); 341 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 342 extern 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 = container_of(kobj, struct device, kobj); 348 return to_i2c_client(dev); 349 } 350 351 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 352 { 353 return dev_get_drvdata(&dev->dev); 354 } 355 356 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 357 { 358 dev_set_drvdata(&dev->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 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 373 extern int i2c_slave_unregister(struct i2c_client *client); 374 extern 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_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 /* Add-on boards should register/unregister their devices; e.g. a board 440 * with integrated I2C, a config eeprom, sensors, and a codec that's 441 * used in conjunction with the primary hardware. 442 */ 443 extern struct i2c_client * 444 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 445 446 extern struct i2c_client * 447 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 448 449 /* If you don't know the exact address of an I2C device, use this variant 450 * instead, which can probe for device presence in a list of possible 451 * addresses. The "probe" callback function is optional. If it is provided, 452 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 453 * a default probing method is used. 454 */ 455 extern struct i2c_client * 456 i2c_new_scanned_device(struct i2c_adapter *adap, 457 struct i2c_board_info *info, 458 unsigned short const *addr_list, 459 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 460 461 extern struct i2c_client * 462 i2c_new_probed_device(struct i2c_adapter *adap, 463 struct i2c_board_info *info, 464 unsigned short const *addr_list, 465 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 466 467 /* Common custom probe functions */ 468 extern int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 469 470 extern struct i2c_client * 471 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 472 473 extern struct i2c_client * 474 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 475 476 extern struct i2c_client * 477 i2c_new_ancillary_device(struct i2c_client *client, 478 const char *name, 479 u16 default_addr); 480 481 extern void i2c_unregister_device(struct i2c_client *client); 482 #endif /* I2C */ 483 484 /* Mainboard arch_initcall() code should register all its I2C devices. 485 * This is done at arch_initcall time, before declaring any i2c adapters. 486 * Modules for add-on boards must use other calls. 487 */ 488 #ifdef CONFIG_I2C_BOARDINFO 489 extern int 490 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 491 unsigned n); 492 #else 493 static inline int 494 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 495 unsigned n) 496 { 497 return 0; 498 } 499 #endif /* I2C_BOARDINFO */ 500 501 /** 502 * struct i2c_algorithm - represent I2C transfer method 503 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 504 * defined by the msgs array, with num messages available to transfer via 505 * the adapter specified by adap. 506 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 507 * so e.g. PMICs can be accessed very late before shutdown. Optional. 508 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 509 * is not present, then the bus layer will try and convert the SMBus calls 510 * into I2C transfers instead. 511 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 512 * so e.g. PMICs can be accessed very late before shutdown. Optional. 513 * @functionality: Return the flags that this algorithm/adapter pair supports 514 * from the I2C_FUNC_* flags. 515 * @reg_slave: Register given client to I2C slave mode of this adapter 516 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 517 * 518 * The following structs are for those who like to implement new bus drivers: 519 * i2c_algorithm is the interface to a class of hardware solutions which can 520 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 521 * to name two of the most common. 522 * 523 * The return codes from the @master_xfer{_atomic} fields should indicate the 524 * type of error code that occurred during the transfer, as documented in the 525 * Kernel Documentation file Documentation/i2c/fault-codes.rst. 526 */ 527 struct i2c_algorithm { 528 /* 529 * If an adapter algorithm can't do I2C-level access, set master_xfer 530 * to NULL. If an adapter algorithm can do SMBus access, set 531 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 532 * using common I2C messages. 533 * 534 * master_xfer should return the number of messages successfully 535 * processed, or a negative value on error 536 */ 537 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 538 int num); 539 int (*master_xfer_atomic)(struct i2c_adapter *adap, 540 struct i2c_msg *msgs, int num); 541 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 542 unsigned short flags, char read_write, 543 u8 command, int size, union i2c_smbus_data *data); 544 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 545 unsigned short flags, char read_write, 546 u8 command, int size, union i2c_smbus_data *data); 547 548 /* To determine what the adapter supports */ 549 u32 (*functionality)(struct i2c_adapter *adap); 550 551 #if IS_ENABLED(CONFIG_I2C_SLAVE) 552 int (*reg_slave)(struct i2c_client *client); 553 int (*unreg_slave)(struct i2c_client *client); 554 #endif 555 }; 556 557 /** 558 * struct i2c_lock_operations - represent I2C locking operations 559 * @lock_bus: Get exclusive access to an I2C bus segment 560 * @trylock_bus: Try to get exclusive access to an I2C bus segment 561 * @unlock_bus: Release exclusive access to an I2C bus segment 562 * 563 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 564 */ 565 struct i2c_lock_operations { 566 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 567 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 568 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 569 }; 570 571 /** 572 * struct i2c_timings - I2C timing information 573 * @bus_freq_hz: the bus frequency in Hz 574 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 575 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 576 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 577 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 578 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 579 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 580 * digital filter can filter out 581 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 582 * analog filter 583 */ 584 struct i2c_timings { 585 u32 bus_freq_hz; 586 u32 scl_rise_ns; 587 u32 scl_fall_ns; 588 u32 scl_int_delay_ns; 589 u32 sda_fall_ns; 590 u32 sda_hold_ns; 591 u32 digital_filter_width_ns; 592 u32 analog_filter_cutoff_freq_hz; 593 }; 594 595 /** 596 * struct i2c_bus_recovery_info - I2C bus recovery information 597 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 598 * i2c_generic_scl_recovery(). 599 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 600 * recovery. Populated internally for generic GPIO recovery. 601 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 602 * Populated internally for generic GPIO recovery. 603 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 604 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 605 * GPIO, for generic GPIO recovery. 606 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 607 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 608 * for generic GPIO recovery. 609 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 610 * has a more complex internal logic than just reading SDA. Optional. 611 * @prepare_recovery: This will be called before starting recovery. Platform may 612 * configure padmux here for SDA/SCL line or something else they want. 613 * @unprepare_recovery: This will be called after completing recovery. Platform 614 * may configure padmux here for SDA/SCL line or something else they want. 615 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 616 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 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 }; 634 635 int i2c_recover_bus(struct i2c_adapter *adap); 636 637 /* Generic recovery routines */ 638 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 639 640 /** 641 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 642 * @flags: see I2C_AQ_* for possible flags and read below 643 * @max_num_msgs: maximum number of messages per transfer 644 * @max_write_len: maximum length of a write message 645 * @max_read_len: maximum length of a read message 646 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 647 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 648 * 649 * Note about combined messages: Some I2C controllers can only send one message 650 * per transfer, plus something called combined message or write-then-read. 651 * This is (usually) a small write message followed by a read message and 652 * barely enough to access register based devices like EEPROMs. There is a flag 653 * to support this mode. It implies max_num_msg = 2 and does the length checks 654 * with max_comb_*_len because combined message mode usually has its own 655 * limitations. Because of HW implementations, some controllers can actually do 656 * write-then-anything or other variants. To support that, write-then-read has 657 * been broken out into smaller bits like write-first and read-second which can 658 * be combined as needed. 659 */ 660 661 struct i2c_adapter_quirks { 662 u64 flags; 663 int max_num_msgs; 664 u16 max_write_len; 665 u16 max_read_len; 666 u16 max_comb_1st_msg_len; 667 u16 max_comb_2nd_msg_len; 668 }; 669 670 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 671 #define I2C_AQ_COMB BIT(0) 672 /* first combined message must be write */ 673 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 674 /* second combined message must be read */ 675 #define I2C_AQ_COMB_READ_SECOND BIT(2) 676 /* both combined messages must have the same target address */ 677 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 678 /* convenience macro for typical write-then read case */ 679 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 680 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 681 /* clock stretching is not supported */ 682 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 683 /* message cannot have length of 0 */ 684 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 685 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 686 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 687 688 /* 689 * i2c_adapter is the structure used to identify a physical i2c bus along 690 * with the access algorithms necessary to access it. 691 */ 692 struct i2c_adapter { 693 struct module *owner; 694 unsigned int class; /* classes to allow probing for */ 695 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 696 void *algo_data; 697 698 /* data fields that are valid for all devices */ 699 const struct i2c_lock_operations *lock_ops; 700 struct rt_mutex bus_lock; 701 struct rt_mutex mux_lock; 702 703 int timeout; /* in jiffies */ 704 int retries; 705 struct device dev; /* the adapter device */ 706 unsigned long locked_flags; /* owned by the I2C core */ 707 #define I2C_ALF_IS_SUSPENDED 0 708 #define I2C_ALF_SUSPEND_REPORTED 1 709 710 int nr; 711 char name[48]; 712 struct completion dev_released; 713 714 struct mutex userspace_clients_lock; 715 struct list_head userspace_clients; 716 717 struct i2c_bus_recovery_info *bus_recovery_info; 718 const struct i2c_adapter_quirks *quirks; 719 720 struct irq_domain *host_notify_domain; 721 }; 722 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 723 724 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 725 { 726 return dev_get_drvdata(&adap->dev); 727 } 728 729 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 730 { 731 dev_set_drvdata(&adap->dev, data); 732 } 733 734 static inline struct i2c_adapter * 735 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 736 { 737 #if IS_ENABLED(CONFIG_I2C_MUX) 738 struct device *parent = adapter->dev.parent; 739 740 if (parent != NULL && parent->type == &i2c_adapter_type) 741 return to_i2c_adapter(parent); 742 else 743 #endif 744 return NULL; 745 } 746 747 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 748 749 /* Adapter locking functions, exported for shared pin cases */ 750 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 751 #define I2C_LOCK_SEGMENT BIT(1) 752 753 /** 754 * i2c_lock_bus - Get exclusive access to an I2C bus segment 755 * @adapter: Target I2C bus segment 756 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 757 * locks only this branch in the adapter tree 758 */ 759 static inline void 760 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 761 { 762 adapter->lock_ops->lock_bus(adapter, flags); 763 } 764 765 /** 766 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 767 * @adapter: Target I2C bus segment 768 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 769 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 770 * 771 * Return: true if the I2C bus segment is locked, false otherwise 772 */ 773 static inline int 774 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 775 { 776 return adapter->lock_ops->trylock_bus(adapter, flags); 777 } 778 779 /** 780 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 781 * @adapter: Target I2C bus segment 782 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 783 * unlocks only this branch in the adapter tree 784 */ 785 static inline void 786 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 787 { 788 adapter->lock_ops->unlock_bus(adapter, flags); 789 } 790 791 /** 792 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 793 * @adap: Adapter to mark as suspended 794 * 795 * When using this helper to mark an adapter as suspended, the core will reject 796 * further transfers to this adapter. The usage of this helper is optional but 797 * recommended for devices having distinct handlers for system suspend and 798 * runtime suspend. More complex devices are free to implement custom solutions 799 * to reject transfers when suspended. 800 */ 801 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 802 { 803 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 804 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 805 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 806 } 807 808 /** 809 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 810 * @adap: Adapter to mark as resumed 811 * 812 * When using this helper to mark an adapter as resumed, the core will allow 813 * further transfers to this adapter. See also further notes to 814 * @i2c_mark_adapter_suspended(). 815 */ 816 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 817 { 818 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 819 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 820 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 821 } 822 823 /* i2c adapter classes (bitmask) */ 824 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 825 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 826 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 827 /* Warn users that the adapter doesn't support classes anymore */ 828 #define I2C_CLASS_DEPRECATED (1<<8) 829 830 /* Internal numbers to terminate lists */ 831 #define I2C_CLIENT_END 0xfffeU 832 833 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 834 #define I2C_ADDRS(addr, addrs...) \ 835 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 836 837 838 /* ----- functions exported by i2c.o */ 839 840 /* administration... 841 */ 842 #if IS_ENABLED(CONFIG_I2C) 843 extern int i2c_add_adapter(struct i2c_adapter *adap); 844 extern void i2c_del_adapter(struct i2c_adapter *adap); 845 extern int i2c_add_numbered_adapter(struct i2c_adapter *adap); 846 847 extern int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 848 extern void i2c_del_driver(struct i2c_driver *driver); 849 850 /* use a define to avoid include chaining to get THIS_MODULE */ 851 #define i2c_add_driver(driver) \ 852 i2c_register_driver(THIS_MODULE, driver) 853 854 static inline bool i2c_client_has_driver(struct i2c_client *client) 855 { 856 return !IS_ERR_OR_NULL(client) && client->dev.driver; 857 } 858 859 /* call the i2c_client->command() of all attached clients with 860 * the given arguments */ 861 extern void i2c_clients_command(struct i2c_adapter *adap, 862 unsigned int cmd, void *arg); 863 864 extern struct i2c_adapter *i2c_get_adapter(int nr); 865 extern void i2c_put_adapter(struct i2c_adapter *adap); 866 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 867 868 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 869 870 /* Return the functionality mask */ 871 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 872 { 873 return adap->algo->functionality(adap); 874 } 875 876 /* Return 1 if adapter supports everything we need, 0 if not. */ 877 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 878 { 879 return (func & i2c_get_functionality(adap)) == func; 880 } 881 882 /** 883 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 884 * @adap: i2c adapter 885 * @quirks: quirk flags 886 * 887 * Return: true if the adapter has all the specified quirk flags, false if not 888 */ 889 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 890 { 891 if (!adap->quirks) 892 return false; 893 return (adap->quirks->flags & quirks) == quirks; 894 } 895 896 /* Return the adapter number for a specific adapter */ 897 static inline int i2c_adapter_id(struct i2c_adapter *adap) 898 { 899 return adap->nr; 900 } 901 902 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 903 { 904 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 905 } 906 907 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 908 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 909 910 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 911 /** 912 * module_i2c_driver() - Helper macro for registering a modular I2C driver 913 * @__i2c_driver: i2c_driver struct 914 * 915 * Helper macro for I2C drivers which do not do anything special in module 916 * init/exit. This eliminates a lot of boilerplate. Each module may only 917 * use this macro once, and calling it replaces module_init() and module_exit() 918 */ 919 #define module_i2c_driver(__i2c_driver) \ 920 module_driver(__i2c_driver, i2c_add_driver, \ 921 i2c_del_driver) 922 923 /** 924 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 925 * @__i2c_driver: i2c_driver struct 926 * 927 * Helper macro for I2C drivers which do not do anything special in their 928 * init. This eliminates a lot of boilerplate. Each driver may only 929 * use this macro once, and calling it replaces device_initcall(). 930 */ 931 #define builtin_i2c_driver(__i2c_driver) \ 932 builtin_driver(__i2c_driver, i2c_add_driver) 933 934 #endif /* I2C */ 935 936 #if IS_ENABLED(CONFIG_OF) 937 /* must call put_device() when done with returned i2c_client device */ 938 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 939 940 /* must call put_device() when done with returned i2c_adapter device */ 941 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 942 943 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 944 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 945 946 extern const struct of_device_id 947 *i2c_of_match_device(const struct of_device_id *matches, 948 struct i2c_client *client); 949 950 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 951 struct i2c_board_info *info); 952 953 #else 954 955 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 956 { 957 return NULL; 958 } 959 960 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 961 { 962 return NULL; 963 } 964 965 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 966 { 967 return NULL; 968 } 969 970 static inline const struct of_device_id 971 *i2c_of_match_device(const struct of_device_id *matches, 972 struct i2c_client *client) 973 { 974 return NULL; 975 } 976 977 static inline int of_i2c_get_board_info(struct device *dev, 978 struct device_node *node, 979 struct i2c_board_info *info) 980 { 981 return -ENOTSUPP; 982 } 983 984 #endif /* CONFIG_OF */ 985 986 struct acpi_resource; 987 struct acpi_resource_i2c_serialbus; 988 989 #if IS_ENABLED(CONFIG_ACPI) 990 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 991 struct acpi_resource_i2c_serialbus **i2c); 992 u32 i2c_acpi_find_bus_speed(struct device *dev); 993 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 994 struct i2c_board_info *info); 995 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 996 #else 997 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 998 struct acpi_resource_i2c_serialbus **i2c) 999 { 1000 return false; 1001 } 1002 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1003 { 1004 return 0; 1005 } 1006 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1007 int index, struct i2c_board_info *info) 1008 { 1009 return NULL; 1010 } 1011 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1012 { 1013 return NULL; 1014 } 1015 #endif /* CONFIG_ACPI */ 1016 1017 #endif /* _LINUX_I2C_H */ 1018