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 <[email protected]> 6 * 7 * With some changes from Kyösti Mälkki <[email protected]> and 8 * Frodo Looijaard <[email protected]> 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 /* Return the Frequency mode string based on the bus frequency */ 55 const char *i2c_freq_mode_string(u32 bus_freq_hz); 56 57 /* 58 * The master routines are the ones normally used to transmit data to devices 59 * on a bus (or read from them). Apart from two basic transfer functions to 60 * transmit one message at a time, a more complex version can be used to 61 * transmit an arbitrary number of messages without interruption. 62 * @count must be less than 64k since msg.len is u16. 63 */ 64 int i2c_transfer_buffer_flags(const struct i2c_client *client, 65 char *buf, int count, u16 flags); 66 67 /** 68 * i2c_master_recv - issue a single I2C message in master receive mode 69 * @client: Handle to slave device 70 * @buf: Where to store data read from slave 71 * @count: How many bytes to read, must be less than 64k since msg.len is u16 72 * 73 * Returns negative errno, or else the number of bytes read. 74 */ 75 static inline int i2c_master_recv(const struct i2c_client *client, 76 char *buf, int count) 77 { 78 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 79 }; 80 81 /** 82 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 83 * using a DMA safe buffer 84 * @client: Handle to slave device 85 * @buf: Where to store data read from slave, must be safe to use with DMA 86 * @count: How many bytes to read, must be less than 64k since msg.len is u16 87 * 88 * Returns negative errno, or else the number of bytes read. 89 */ 90 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 91 char *buf, int count) 92 { 93 return i2c_transfer_buffer_flags(client, buf, count, 94 I2C_M_RD | I2C_M_DMA_SAFE); 95 }; 96 97 /** 98 * i2c_master_send - issue a single I2C message in master transmit mode 99 * @client: Handle to slave device 100 * @buf: Data that will be written to the slave 101 * @count: How many bytes to write, must be less than 64k since msg.len is u16 102 * 103 * Returns negative errno, or else the number of bytes written. 104 */ 105 static inline int i2c_master_send(const struct i2c_client *client, 106 const char *buf, int count) 107 { 108 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 109 }; 110 111 /** 112 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 113 * using a DMA safe buffer 114 * @client: Handle to slave device 115 * @buf: Data that will be written to the slave, must be safe to use with DMA 116 * @count: How many bytes to write, must be less than 64k since msg.len is u16 117 * 118 * Returns negative errno, or else the number of bytes written. 119 */ 120 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 121 const char *buf, int count) 122 { 123 return i2c_transfer_buffer_flags(client, (char *)buf, count, 124 I2C_M_DMA_SAFE); 125 }; 126 127 /* Transfer num messages. 128 */ 129 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 130 /* Unlocked flavor */ 131 int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 132 133 /* This is the very generalized SMBus access routine. You probably do not 134 want to use this, though; one of the functions below may be much easier, 135 and probably just as fast. 136 Note that we use i2c_adapter here, because you do not need a specific 137 smbus adapter to call this function. */ 138 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 139 unsigned short flags, char read_write, u8 command, 140 int protocol, union i2c_smbus_data *data); 141 142 /* Unlocked flavor */ 143 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 144 unsigned short flags, char read_write, u8 command, 145 int protocol, union i2c_smbus_data *data); 146 147 /* Now follow the 'nice' access routines. These also document the calling 148 conventions of i2c_smbus_xfer. */ 149 150 s32 i2c_smbus_read_byte(const struct i2c_client *client); 151 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 152 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 153 s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 154 u8 command, u8 value); 155 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 156 s32 i2c_smbus_write_word_data(const struct i2c_client *client, 157 u8 command, u16 value); 158 159 static inline s32 160 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 161 { 162 s32 value = i2c_smbus_read_word_data(client, command); 163 164 return (value < 0) ? value : swab16(value); 165 } 166 167 static inline s32 168 i2c_smbus_write_word_swapped(const struct i2c_client *client, 169 u8 command, u16 value) 170 { 171 return i2c_smbus_write_word_data(client, command, swab16(value)); 172 } 173 174 /* Returns the number of read bytes */ 175 s32 i2c_smbus_read_block_data(const struct i2c_client *client, 176 u8 command, u8 *values); 177 s32 i2c_smbus_write_block_data(const struct i2c_client *client, 178 u8 command, u8 length, const u8 *values); 179 /* Returns the number of read bytes */ 180 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 181 u8 command, u8 length, u8 *values); 182 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 183 u8 command, u8 length, const u8 *values); 184 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 185 u8 command, u8 length, 186 u8 *values); 187 int i2c_get_device_id(const struct i2c_client *client, 188 struct i2c_device_identity *id); 189 #endif /* I2C */ 190 191 /** 192 * struct i2c_device_identity - i2c client device identification 193 * @manufacturer_id: 0 - 4095, database maintained by NXP 194 * @part_id: 0 - 511, according to manufacturer 195 * @die_revision: 0 - 7, according to manufacturer 196 */ 197 struct i2c_device_identity { 198 u16 manufacturer_id; 199 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 200 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 201 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 202 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 203 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 204 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 205 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 206 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 207 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 208 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 209 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 210 #define I2C_DEVICE_ID_FLIR 11 211 #define I2C_DEVICE_ID_O2MICRO 12 212 #define I2C_DEVICE_ID_ATMEL 13 213 #define I2C_DEVICE_ID_NONE 0xffff 214 u16 part_id; 215 u8 die_revision; 216 }; 217 218 enum i2c_alert_protocol { 219 I2C_PROTOCOL_SMBUS_ALERT, 220 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 221 }; 222 223 /** 224 * struct i2c_driver - represent an I2C device driver 225 * @class: What kind of i2c device we instantiate (for detect) 226 * @probe: Callback for device binding - soon to be deprecated 227 * @probe_new: New callback for device binding 228 * @remove: Callback for device unbinding 229 * @shutdown: Callback for device shutdown 230 * @alert: Alert callback, for example for the SMBus alert protocol 231 * @command: Callback for bus-wide signaling (optional) 232 * @driver: Device driver model driver 233 * @id_table: List of I2C devices supported by this driver 234 * @detect: Callback for device detection 235 * @address_list: The I2C addresses to probe (for detect) 236 * @clients: List of detected clients we created (for i2c-core use only) 237 * 238 * The driver.owner field should be set to the module owner of this driver. 239 * The driver.name field should be set to the name of this driver. 240 * 241 * For automatic device detection, both @detect and @address_list must 242 * be defined. @class should also be set, otherwise only devices forced 243 * with module parameters will be created. The detect function must 244 * fill at least the name field of the i2c_board_info structure it is 245 * handed upon successful detection, and possibly also the flags field. 246 * 247 * If @detect is missing, the driver will still work fine for enumerated 248 * devices. Detected devices simply won't be supported. This is expected 249 * for the many I2C/SMBus devices which can't be detected reliably, and 250 * the ones which can always be enumerated in practice. 251 * 252 * The i2c_client structure which is handed to the @detect callback is 253 * not a real i2c_client. It is initialized just enough so that you can 254 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 255 * else with it. In particular, calling dev_dbg and friends on it is 256 * not allowed. 257 */ 258 struct i2c_driver { 259 unsigned int class; 260 261 /* Standard driver model interfaces */ 262 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id); 263 int (*remove)(struct i2c_client *client); 264 265 /* New driver model interface to aid the seamless removal of the 266 * current probe()'s, more commonly unused than used second parameter. 267 */ 268 int (*probe_new)(struct i2c_client *client); 269 270 /* driver model interfaces that don't relate to enumeration */ 271 void (*shutdown)(struct i2c_client *client); 272 273 /* Alert callback, for example for the SMBus alert protocol. 274 * The format and meaning of the data value depends on the protocol. 275 * For the SMBus alert protocol, there is a single bit of data passed 276 * as the alert response's low bit ("event flag"). 277 * For the SMBus Host Notify protocol, the data corresponds to the 278 * 16-bit payload data reported by the slave device acting as master. 279 */ 280 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 281 unsigned int data); 282 283 /* a ioctl like command that can be used to perform specific functions 284 * with the device. 285 */ 286 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 287 288 struct device_driver driver; 289 const struct i2c_device_id *id_table; 290 291 /* Device detection callback for automatic device creation */ 292 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 293 const unsigned short *address_list; 294 struct list_head clients; 295 }; 296 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 297 298 /** 299 * struct i2c_client - represent an I2C slave device 300 * @flags: see I2C_CLIENT_* for possible flags 301 * @addr: Address used on the I2C bus connected to the parent adapter. 302 * @name: Indicates the type of the device, usually a chip name that's 303 * generic enough to hide second-sourcing and compatible revisions. 304 * @adapter: manages the bus segment hosting this I2C device 305 * @dev: Driver model device node for the slave. 306 * @init_irq: IRQ that was set at initialization 307 * @irq: indicates the IRQ generated by this device (if any) 308 * @detected: member of an i2c_driver.clients list or i2c-core's 309 * userspace_devices list 310 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 311 * calls it to pass on slave events to the slave driver. 312 * @devres_group_id: id of the devres group that will be created for resources 313 * acquired when probing this device. 314 * 315 * An i2c_client identifies a single device (i.e. chip) connected to an 316 * i2c bus. The behaviour exposed to Linux is defined by the driver 317 * managing the device. 318 */ 319 struct i2c_client { 320 unsigned short flags; /* div., see below */ 321 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 322 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 323 /* Must equal I2C_M_TEN below */ 324 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 325 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 326 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 327 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 328 /* Must match I2C_M_STOP|IGNORE_NAK */ 329 330 unsigned short addr; /* chip address - NOTE: 7bit */ 331 /* addresses are stored in the */ 332 /* _LOWER_ 7 bits */ 333 char name[I2C_NAME_SIZE]; 334 struct i2c_adapter *adapter; /* the adapter we sit on */ 335 struct device dev; /* the device structure */ 336 int init_irq; /* irq set at initialization */ 337 int irq; /* irq issued by device */ 338 struct list_head detected; 339 #if IS_ENABLED(CONFIG_I2C_SLAVE) 340 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 341 #endif 342 void *devres_group_id; /* ID of probe devres group */ 343 }; 344 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 345 346 struct i2c_adapter *i2c_verify_adapter(struct device *dev); 347 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 348 const struct i2c_client *client); 349 350 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 351 { 352 struct device * const dev = kobj_to_dev(kobj); 353 return to_i2c_client(dev); 354 } 355 356 static inline void *i2c_get_clientdata(const struct i2c_client *client) 357 { 358 return dev_get_drvdata(&client->dev); 359 } 360 361 static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 362 { 363 dev_set_drvdata(&client->dev, data); 364 } 365 366 /* I2C slave support */ 367 368 #if IS_ENABLED(CONFIG_I2C_SLAVE) 369 enum i2c_slave_event { 370 I2C_SLAVE_READ_REQUESTED, 371 I2C_SLAVE_WRITE_REQUESTED, 372 I2C_SLAVE_READ_PROCESSED, 373 I2C_SLAVE_WRITE_RECEIVED, 374 I2C_SLAVE_STOP, 375 }; 376 377 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 378 int i2c_slave_unregister(struct i2c_client *client); 379 bool i2c_detect_slave_mode(struct device *dev); 380 381 static inline int i2c_slave_event(struct i2c_client *client, 382 enum i2c_slave_event event, u8 *val) 383 { 384 return client->slave_cb(client, event, val); 385 } 386 #else 387 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 388 #endif 389 390 /** 391 * struct i2c_board_info - template for device creation 392 * @type: chip type, to initialize i2c_client.name 393 * @flags: to initialize i2c_client.flags 394 * @addr: stored in i2c_client.addr 395 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 396 * @platform_data: stored in i2c_client.dev.platform_data 397 * @of_node: pointer to OpenFirmware device node 398 * @fwnode: device node supplied by the platform firmware 399 * @swnode: software node for the device 400 * @resources: resources associated with the device 401 * @num_resources: number of resources in the @resources array 402 * @irq: stored in i2c_client.irq 403 * 404 * I2C doesn't actually support hardware probing, although controllers and 405 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 406 * a device at a given address. Drivers commonly need more information than 407 * that, such as chip type, configuration, associated IRQ, and so on. 408 * 409 * i2c_board_info is used to build tables of information listing I2C devices 410 * that are present. This information is used to grow the driver model tree. 411 * For mainboards this is done statically using i2c_register_board_info(); 412 * bus numbers identify adapters that aren't yet available. For add-on boards, 413 * i2c_new_client_device() does this dynamically with the adapter already known. 414 */ 415 struct i2c_board_info { 416 char type[I2C_NAME_SIZE]; 417 unsigned short flags; 418 unsigned short addr; 419 const char *dev_name; 420 void *platform_data; 421 struct device_node *of_node; 422 struct fwnode_handle *fwnode; 423 const struct software_node *swnode; 424 const struct resource *resources; 425 unsigned int num_resources; 426 int irq; 427 }; 428 429 /** 430 * I2C_BOARD_INFO - macro used to list an i2c device and its address 431 * @dev_type: identifies the device type 432 * @dev_addr: the device's address on the bus. 433 * 434 * This macro initializes essential fields of a struct i2c_board_info, 435 * declaring what has been provided on a particular board. Optional 436 * fields (such as associated irq, or device-specific platform_data) 437 * are provided using conventional syntax. 438 */ 439 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 440 .type = dev_type, .addr = (dev_addr) 441 442 443 #if IS_ENABLED(CONFIG_I2C) 444 /* 445 * Add-on boards should register/unregister their devices; e.g. a board 446 * with integrated I2C, a config eeprom, sensors, and a codec that's 447 * used in conjunction with the primary hardware. 448 */ 449 struct i2c_client * 450 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 451 452 /* If you don't know the exact address of an I2C device, use this variant 453 * instead, which can probe for device presence in a list of possible 454 * addresses. The "probe" callback function is optional. If it is provided, 455 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 456 * a default probing method is used. 457 */ 458 struct i2c_client * 459 i2c_new_scanned_device(struct i2c_adapter *adap, 460 struct i2c_board_info *info, 461 unsigned short const *addr_list, 462 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 463 464 /* Common custom probe functions */ 465 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 466 467 struct i2c_client * 468 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 469 470 struct i2c_client * 471 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 472 473 struct i2c_client * 474 i2c_new_ancillary_device(struct i2c_client *client, 475 const char *name, 476 u16 default_addr); 477 478 void i2c_unregister_device(struct i2c_client *client); 479 480 struct i2c_client *i2c_verify_client(struct device *dev); 481 #else 482 static inline struct i2c_client *i2c_verify_client(struct device *dev) 483 { 484 return NULL; 485 } 486 #endif /* I2C */ 487 488 /* Mainboard arch_initcall() code should register all its I2C devices. 489 * This is done at arch_initcall time, before declaring any i2c adapters. 490 * Modules for add-on boards must use other calls. 491 */ 492 #ifdef CONFIG_I2C_BOARDINFO 493 int 494 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 495 unsigned n); 496 #else 497 static inline int 498 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 499 unsigned n) 500 { 501 return 0; 502 } 503 #endif /* I2C_BOARDINFO */ 504 505 /** 506 * struct i2c_algorithm - represent I2C transfer method 507 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 508 * defined by the msgs array, with num messages available to transfer via 509 * the adapter specified by adap. 510 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 511 * so e.g. PMICs can be accessed very late before shutdown. Optional. 512 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 513 * is not present, then the bus layer will try and convert the SMBus calls 514 * into I2C transfers instead. 515 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 516 * so e.g. PMICs can be accessed very late before shutdown. Optional. 517 * @functionality: Return the flags that this algorithm/adapter pair supports 518 * from the ``I2C_FUNC_*`` flags. 519 * @reg_slave: Register given client to I2C slave mode of this adapter 520 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 521 * 522 * The following structs are for those who like to implement new bus drivers: 523 * i2c_algorithm is the interface to a class of hardware solutions which can 524 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 525 * to name two of the most common. 526 * 527 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 528 * type of error code that occurred during the transfer, as documented in the 529 * Kernel Documentation file Documentation/i2c/fault-codes.rst. 530 */ 531 struct i2c_algorithm { 532 /* 533 * If an adapter algorithm can't do I2C-level access, set master_xfer 534 * to NULL. If an adapter algorithm can do SMBus access, set 535 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 536 * using common I2C messages. 537 * 538 * master_xfer should return the number of messages successfully 539 * processed, or a negative value on error 540 */ 541 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 542 int num); 543 int (*master_xfer_atomic)(struct i2c_adapter *adap, 544 struct i2c_msg *msgs, int num); 545 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 546 unsigned short flags, char read_write, 547 u8 command, int size, union i2c_smbus_data *data); 548 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 549 unsigned short flags, char read_write, 550 u8 command, int size, union i2c_smbus_data *data); 551 552 /* To determine what the adapter supports */ 553 u32 (*functionality)(struct i2c_adapter *adap); 554 555 #if IS_ENABLED(CONFIG_I2C_SLAVE) 556 int (*reg_slave)(struct i2c_client *client); 557 int (*unreg_slave)(struct i2c_client *client); 558 #endif 559 }; 560 561 /** 562 * struct i2c_lock_operations - represent I2C locking operations 563 * @lock_bus: Get exclusive access to an I2C bus segment 564 * @trylock_bus: Try to get exclusive access to an I2C bus segment 565 * @unlock_bus: Release exclusive access to an I2C bus segment 566 * 567 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 568 */ 569 struct i2c_lock_operations { 570 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 571 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 572 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 573 }; 574 575 /** 576 * struct i2c_timings - I2C timing information 577 * @bus_freq_hz: the bus frequency in Hz 578 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 579 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 580 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 581 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 582 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 583 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 584 * digital filter can filter out 585 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 586 * analog filter 587 */ 588 struct i2c_timings { 589 u32 bus_freq_hz; 590 u32 scl_rise_ns; 591 u32 scl_fall_ns; 592 u32 scl_int_delay_ns; 593 u32 sda_fall_ns; 594 u32 sda_hold_ns; 595 u32 digital_filter_width_ns; 596 u32 analog_filter_cutoff_freq_hz; 597 }; 598 599 /** 600 * struct i2c_bus_recovery_info - I2C bus recovery information 601 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 602 * i2c_generic_scl_recovery(). 603 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 604 * recovery. Populated internally for generic GPIO recovery. 605 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 606 * Populated internally for generic GPIO recovery. 607 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 608 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 609 * GPIO, for generic GPIO recovery. 610 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 611 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 612 * for generic GPIO recovery. 613 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 614 * has a more complex internal logic than just reading SDA. Optional. 615 * @prepare_recovery: This will be called before starting recovery. Platform may 616 * configure padmux here for SDA/SCL line or something else they want. 617 * @unprepare_recovery: This will be called after completing recovery. Platform 618 * may configure padmux here for SDA/SCL line or something else they want. 619 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 620 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 621 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 622 * Optional. 623 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 624 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 625 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 626 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 627 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 628 * is called "gpio" or "recovery" and pinctrl is valid. 629 */ 630 struct i2c_bus_recovery_info { 631 int (*recover_bus)(struct i2c_adapter *adap); 632 633 int (*get_scl)(struct i2c_adapter *adap); 634 void (*set_scl)(struct i2c_adapter *adap, int val); 635 int (*get_sda)(struct i2c_adapter *adap); 636 void (*set_sda)(struct i2c_adapter *adap, int val); 637 int (*get_bus_free)(struct i2c_adapter *adap); 638 639 void (*prepare_recovery)(struct i2c_adapter *adap); 640 void (*unprepare_recovery)(struct i2c_adapter *adap); 641 642 /* gpio recovery */ 643 struct gpio_desc *scl_gpiod; 644 struct gpio_desc *sda_gpiod; 645 struct pinctrl *pinctrl; 646 struct pinctrl_state *pins_default; 647 struct pinctrl_state *pins_gpio; 648 }; 649 650 int i2c_recover_bus(struct i2c_adapter *adap); 651 652 /* Generic recovery routines */ 653 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 654 655 /** 656 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 657 * @flags: see I2C_AQ_* for possible flags and read below 658 * @max_num_msgs: maximum number of messages per transfer 659 * @max_write_len: maximum length of a write message 660 * @max_read_len: maximum length of a read message 661 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 662 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 663 * 664 * Note about combined messages: Some I2C controllers can only send one message 665 * per transfer, plus something called combined message or write-then-read. 666 * This is (usually) a small write message followed by a read message and 667 * barely enough to access register based devices like EEPROMs. There is a flag 668 * to support this mode. It implies max_num_msg = 2 and does the length checks 669 * with max_comb_*_len because combined message mode usually has its own 670 * limitations. Because of HW implementations, some controllers can actually do 671 * write-then-anything or other variants. To support that, write-then-read has 672 * been broken out into smaller bits like write-first and read-second which can 673 * be combined as needed. 674 */ 675 676 struct i2c_adapter_quirks { 677 u64 flags; 678 int max_num_msgs; 679 u16 max_write_len; 680 u16 max_read_len; 681 u16 max_comb_1st_msg_len; 682 u16 max_comb_2nd_msg_len; 683 }; 684 685 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 686 #define I2C_AQ_COMB BIT(0) 687 /* first combined message must be write */ 688 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 689 /* second combined message must be read */ 690 #define I2C_AQ_COMB_READ_SECOND BIT(2) 691 /* both combined messages must have the same target address */ 692 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 693 /* convenience macro for typical write-then read case */ 694 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 695 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 696 /* clock stretching is not supported */ 697 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 698 /* message cannot have length of 0 */ 699 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 700 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 701 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 702 /* adapter cannot do repeated START */ 703 #define I2C_AQ_NO_REP_START BIT(7) 704 705 /* 706 * i2c_adapter is the structure used to identify a physical i2c bus along 707 * with the access algorithms necessary to access it. 708 */ 709 struct i2c_adapter { 710 struct module *owner; 711 unsigned int class; /* classes to allow probing for */ 712 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 713 void *algo_data; 714 715 /* data fields that are valid for all devices */ 716 const struct i2c_lock_operations *lock_ops; 717 struct rt_mutex bus_lock; 718 struct rt_mutex mux_lock; 719 720 int timeout; /* in jiffies */ 721 int retries; 722 struct device dev; /* the adapter device */ 723 unsigned long locked_flags; /* owned by the I2C core */ 724 #define I2C_ALF_IS_SUSPENDED 0 725 #define I2C_ALF_SUSPEND_REPORTED 1 726 727 int nr; 728 char name[48]; 729 struct completion dev_released; 730 731 struct mutex userspace_clients_lock; 732 struct list_head userspace_clients; 733 734 struct i2c_bus_recovery_info *bus_recovery_info; 735 const struct i2c_adapter_quirks *quirks; 736 737 struct irq_domain *host_notify_domain; 738 }; 739 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 740 741 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 742 { 743 return dev_get_drvdata(&adap->dev); 744 } 745 746 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 747 { 748 dev_set_drvdata(&adap->dev, data); 749 } 750 751 static inline struct i2c_adapter * 752 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 753 { 754 #if IS_ENABLED(CONFIG_I2C_MUX) 755 struct device *parent = adapter->dev.parent; 756 757 if (parent != NULL && parent->type == &i2c_adapter_type) 758 return to_i2c_adapter(parent); 759 else 760 #endif 761 return NULL; 762 } 763 764 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 765 766 /* Adapter locking functions, exported for shared pin cases */ 767 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 768 #define I2C_LOCK_SEGMENT BIT(1) 769 770 /** 771 * i2c_lock_bus - Get exclusive access to an I2C bus segment 772 * @adapter: Target I2C bus segment 773 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 774 * locks only this branch in the adapter tree 775 */ 776 static inline void 777 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 778 { 779 adapter->lock_ops->lock_bus(adapter, flags); 780 } 781 782 /** 783 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 784 * @adapter: Target I2C bus segment 785 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 786 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 787 * 788 * Return: true if the I2C bus segment is locked, false otherwise 789 */ 790 static inline int 791 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 792 { 793 return adapter->lock_ops->trylock_bus(adapter, flags); 794 } 795 796 /** 797 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 798 * @adapter: Target I2C bus segment 799 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 800 * unlocks only this branch in the adapter tree 801 */ 802 static inline void 803 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 804 { 805 adapter->lock_ops->unlock_bus(adapter, flags); 806 } 807 808 /** 809 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 810 * @adap: Adapter to mark as suspended 811 * 812 * When using this helper to mark an adapter as suspended, the core will reject 813 * further transfers to this adapter. The usage of this helper is optional but 814 * recommended for devices having distinct handlers for system suspend and 815 * runtime suspend. More complex devices are free to implement custom solutions 816 * to reject transfers when suspended. 817 */ 818 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 819 { 820 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 821 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 822 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 823 } 824 825 /** 826 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 827 * @adap: Adapter to mark as resumed 828 * 829 * When using this helper to mark an adapter as resumed, the core will allow 830 * further transfers to this adapter. See also further notes to 831 * @i2c_mark_adapter_suspended(). 832 */ 833 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 834 { 835 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 836 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 837 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 838 } 839 840 /* i2c adapter classes (bitmask) */ 841 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 842 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 843 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 844 /* Warn users that the adapter doesn't support classes anymore */ 845 #define I2C_CLASS_DEPRECATED (1<<8) 846 847 /* Internal numbers to terminate lists */ 848 #define I2C_CLIENT_END 0xfffeU 849 850 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 851 #define I2C_ADDRS(addr, addrs...) \ 852 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 853 854 855 /* ----- functions exported by i2c.o */ 856 857 /* administration... 858 */ 859 #if IS_ENABLED(CONFIG_I2C) 860 int i2c_add_adapter(struct i2c_adapter *adap); 861 int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); 862 void i2c_del_adapter(struct i2c_adapter *adap); 863 int i2c_add_numbered_adapter(struct i2c_adapter *adap); 864 865 int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 866 void i2c_del_driver(struct i2c_driver *driver); 867 868 /* use a define to avoid include chaining to get THIS_MODULE */ 869 #define i2c_add_driver(driver) \ 870 i2c_register_driver(THIS_MODULE, driver) 871 872 static inline bool i2c_client_has_driver(struct i2c_client *client) 873 { 874 return !IS_ERR_OR_NULL(client) && client->dev.driver; 875 } 876 877 /* call the i2c_client->command() of all attached clients with 878 * the given arguments */ 879 void i2c_clients_command(struct i2c_adapter *adap, 880 unsigned int cmd, void *arg); 881 882 struct i2c_adapter *i2c_get_adapter(int nr); 883 void i2c_put_adapter(struct i2c_adapter *adap); 884 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 885 886 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 887 888 /* Return the functionality mask */ 889 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 890 { 891 return adap->algo->functionality(adap); 892 } 893 894 /* Return 1 if adapter supports everything we need, 0 if not. */ 895 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 896 { 897 return (func & i2c_get_functionality(adap)) == func; 898 } 899 900 /** 901 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 902 * @adap: i2c adapter 903 * @quirks: quirk flags 904 * 905 * Return: true if the adapter has all the specified quirk flags, false if not 906 */ 907 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 908 { 909 if (!adap->quirks) 910 return false; 911 return (adap->quirks->flags & quirks) == quirks; 912 } 913 914 /* Return the adapter number for a specific adapter */ 915 static inline int i2c_adapter_id(struct i2c_adapter *adap) 916 { 917 return adap->nr; 918 } 919 920 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 921 { 922 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 923 } 924 925 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 926 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 927 928 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 929 /** 930 * module_i2c_driver() - Helper macro for registering a modular I2C driver 931 * @__i2c_driver: i2c_driver struct 932 * 933 * Helper macro for I2C drivers which do not do anything special in module 934 * init/exit. This eliminates a lot of boilerplate. Each module may only 935 * use this macro once, and calling it replaces module_init() and module_exit() 936 */ 937 #define module_i2c_driver(__i2c_driver) \ 938 module_driver(__i2c_driver, i2c_add_driver, \ 939 i2c_del_driver) 940 941 /** 942 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 943 * @__i2c_driver: i2c_driver struct 944 * 945 * Helper macro for I2C drivers which do not do anything special in their 946 * init. This eliminates a lot of boilerplate. Each driver may only 947 * use this macro once, and calling it replaces device_initcall(). 948 */ 949 #define builtin_i2c_driver(__i2c_driver) \ 950 builtin_driver(__i2c_driver, i2c_add_driver) 951 952 #endif /* I2C */ 953 954 #if IS_ENABLED(CONFIG_OF) 955 /* must call put_device() when done with returned i2c_client device */ 956 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 957 958 /* must call put_device() when done with returned i2c_adapter device */ 959 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 960 961 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 962 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 963 964 const struct of_device_id 965 *i2c_of_match_device(const struct of_device_id *matches, 966 struct i2c_client *client); 967 968 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 969 struct i2c_board_info *info); 970 971 #else 972 973 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 974 { 975 return NULL; 976 } 977 978 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 979 { 980 return NULL; 981 } 982 983 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 984 { 985 return NULL; 986 } 987 988 static inline const struct of_device_id 989 *i2c_of_match_device(const struct of_device_id *matches, 990 struct i2c_client *client) 991 { 992 return NULL; 993 } 994 995 static inline int of_i2c_get_board_info(struct device *dev, 996 struct device_node *node, 997 struct i2c_board_info *info) 998 { 999 return -ENOTSUPP; 1000 } 1001 1002 #endif /* CONFIG_OF */ 1003 1004 struct acpi_resource; 1005 struct acpi_resource_i2c_serialbus; 1006 1007 #if IS_ENABLED(CONFIG_ACPI) 1008 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1009 struct acpi_resource_i2c_serialbus **i2c); 1010 u32 i2c_acpi_find_bus_speed(struct device *dev); 1011 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 1012 struct i2c_board_info *info); 1013 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 1014 #else 1015 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1016 struct acpi_resource_i2c_serialbus **i2c) 1017 { 1018 return false; 1019 } 1020 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1021 { 1022 return 0; 1023 } 1024 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1025 int index, struct i2c_board_info *info) 1026 { 1027 return ERR_PTR(-ENODEV); 1028 } 1029 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1030 { 1031 return NULL; 1032 } 1033 #endif /* CONFIG_ACPI */ 1034 1035 #endif /* _LINUX_I2C_H */ 1036