1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * i2c.h - definitions for the Linux i2c bus interface 4 * Copyright (C) 1995-2000 Simon G. Vogl 5 * Copyright (C) 2013-2019 Wolfram Sang <wsa@kernel.org> 6 * 7 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and 8 * Frodo Looijaard <frodol@dds.nl> 9 */ 10 #ifndef _LINUX_I2C_H 11 #define _LINUX_I2C_H 12 13 #include <linux/acpi.h> /* for acpi_handle */ 14 #include <linux/bits.h> 15 #include <linux/mod_devicetable.h> 16 #include <linux/device.h> /* for struct device */ 17 #include <linux/sched.h> /* for completion */ 18 #include <linux/mutex.h> 19 #include <linux/regulator/consumer.h> 20 #include <linux/rtmutex.h> 21 #include <linux/irqdomain.h> /* for Host Notify IRQ */ 22 #include <linux/of.h> /* for struct device_node */ 23 #include <linux/swab.h> /* for swab16 */ 24 #include <uapi/linux/i2c.h> 25 26 extern struct bus_type i2c_bus_type; 27 extern struct device_type i2c_adapter_type; 28 extern struct device_type i2c_client_type; 29 30 /* --- General options ------------------------------------------------ */ 31 32 struct i2c_msg; 33 struct i2c_algorithm; 34 struct i2c_adapter; 35 struct i2c_client; 36 struct i2c_driver; 37 struct i2c_device_identity; 38 union i2c_smbus_data; 39 struct i2c_board_info; 40 enum i2c_slave_event; 41 typedef int (*i2c_slave_cb_t)(struct i2c_client *client, 42 enum i2c_slave_event event, u8 *val); 43 44 /* I2C Frequency Modes */ 45 #define I2C_MAX_STANDARD_MODE_FREQ 100000 46 #define I2C_MAX_FAST_MODE_FREQ 400000 47 #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000 48 #define I2C_MAX_TURBO_MODE_FREQ 1400000 49 #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000 50 #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000 51 52 struct module; 53 struct property_entry; 54 55 #if IS_ENABLED(CONFIG_I2C) 56 /* Return the Frequency mode string based on the bus frequency */ 57 const char *i2c_freq_mode_string(u32 bus_freq_hz); 58 59 /* 60 * The master routines are the ones normally used to transmit data to devices 61 * on a bus (or read from them). Apart from two basic transfer functions to 62 * transmit one message at a time, a more complex version can be used to 63 * transmit an arbitrary number of messages without interruption. 64 * @count must be less than 64k since msg.len is u16. 65 */ 66 int i2c_transfer_buffer_flags(const struct i2c_client *client, 67 char *buf, int count, u16 flags); 68 69 /** 70 * i2c_master_recv - issue a single I2C message in master receive mode 71 * @client: Handle to slave device 72 * @buf: Where to store data read from slave 73 * @count: How many bytes to read, must be less than 64k since msg.len is u16 74 * 75 * Returns negative errno, or else the number of bytes read. 76 */ 77 static inline int i2c_master_recv(const struct i2c_client *client, 78 char *buf, int count) 79 { 80 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 81 }; 82 83 /** 84 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 85 * using a DMA safe buffer 86 * @client: Handle to slave device 87 * @buf: Where to store data read from slave, must be safe to use with DMA 88 * @count: How many bytes to read, must be less than 64k since msg.len is u16 89 * 90 * Returns negative errno, or else the number of bytes read. 91 */ 92 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 93 char *buf, int count) 94 { 95 return i2c_transfer_buffer_flags(client, buf, count, 96 I2C_M_RD | I2C_M_DMA_SAFE); 97 }; 98 99 /** 100 * i2c_master_send - issue a single I2C message in master transmit mode 101 * @client: Handle to slave device 102 * @buf: Data that will be written to the slave 103 * @count: How many bytes to write, must be less than 64k since msg.len is u16 104 * 105 * Returns negative errno, or else the number of bytes written. 106 */ 107 static inline int i2c_master_send(const struct i2c_client *client, 108 const char *buf, int count) 109 { 110 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 111 }; 112 113 /** 114 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 115 * using a DMA safe buffer 116 * @client: Handle to slave device 117 * @buf: Data that will be written to the slave, must be safe to use with DMA 118 * @count: How many bytes to write, must be less than 64k since msg.len is u16 119 * 120 * Returns negative errno, or else the number of bytes written. 121 */ 122 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 123 const char *buf, int count) 124 { 125 return i2c_transfer_buffer_flags(client, (char *)buf, count, 126 I2C_M_DMA_SAFE); 127 }; 128 129 /* Transfer num messages. 130 */ 131 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 132 /* Unlocked flavor */ 133 int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); 134 135 /* This is the very generalized SMBus access routine. You probably do not 136 want to use this, though; one of the functions below may be much easier, 137 and probably just as fast. 138 Note that we use i2c_adapter here, because you do not need a specific 139 smbus adapter to call this function. */ 140 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 141 unsigned short flags, char read_write, u8 command, 142 int protocol, union i2c_smbus_data *data); 143 144 /* Unlocked flavor */ 145 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 146 unsigned short flags, char read_write, u8 command, 147 int protocol, union i2c_smbus_data *data); 148 149 /* Now follow the 'nice' access routines. These also document the calling 150 conventions of i2c_smbus_xfer. */ 151 152 u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count); 153 s32 i2c_smbus_read_byte(const struct i2c_client *client); 154 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 155 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command); 156 s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 157 u8 command, u8 value); 158 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command); 159 s32 i2c_smbus_write_word_data(const struct i2c_client *client, 160 u8 command, u16 value); 161 162 static inline s32 163 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 164 { 165 s32 value = i2c_smbus_read_word_data(client, command); 166 167 return (value < 0) ? value : swab16(value); 168 } 169 170 static inline s32 171 i2c_smbus_write_word_swapped(const struct i2c_client *client, 172 u8 command, u16 value) 173 { 174 return i2c_smbus_write_word_data(client, command, swab16(value)); 175 } 176 177 /* Returns the number of read bytes */ 178 s32 i2c_smbus_read_block_data(const struct i2c_client *client, 179 u8 command, u8 *values); 180 s32 i2c_smbus_write_block_data(const struct i2c_client *client, 181 u8 command, u8 length, const u8 *values); 182 /* Returns the number of read bytes */ 183 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 184 u8 command, u8 length, u8 *values); 185 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 186 u8 command, u8 length, const u8 *values); 187 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 188 u8 command, u8 length, 189 u8 *values); 190 int i2c_get_device_id(const struct i2c_client *client, 191 struct i2c_device_identity *id); 192 const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client); 193 #endif /* I2C */ 194 195 /** 196 * struct i2c_device_identity - i2c client device identification 197 * @manufacturer_id: 0 - 4095, database maintained by NXP 198 * @part_id: 0 - 511, according to manufacturer 199 * @die_revision: 0 - 7, according to manufacturer 200 */ 201 struct i2c_device_identity { 202 u16 manufacturer_id; 203 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 204 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 205 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 206 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 207 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 208 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 209 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 210 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 211 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 212 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 213 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 214 #define I2C_DEVICE_ID_FLIR 11 215 #define I2C_DEVICE_ID_O2MICRO 12 216 #define I2C_DEVICE_ID_ATMEL 13 217 #define I2C_DEVICE_ID_NONE 0xffff 218 u16 part_id; 219 u8 die_revision; 220 }; 221 222 enum i2c_alert_protocol { 223 I2C_PROTOCOL_SMBUS_ALERT, 224 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 225 }; 226 227 /** 228 * enum i2c_driver_flags - Flags for an I2C device driver 229 * 230 * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe 231 */ 232 enum i2c_driver_flags { 233 I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0), 234 }; 235 236 /** 237 * struct i2c_driver - represent an I2C device driver 238 * @class: What kind of i2c device we instantiate (for detect) 239 * @probe: Callback for device binding - soon to be deprecated 240 * @probe_new: New callback for device binding 241 * @remove: Callback for device unbinding 242 * @shutdown: Callback for device shutdown 243 * @alert: Alert callback, for example for the SMBus alert protocol 244 * @command: Callback for bus-wide signaling (optional) 245 * @driver: Device driver model driver 246 * @id_table: List of I2C devices supported by this driver 247 * @detect: Callback for device detection 248 * @address_list: The I2C addresses to probe (for detect) 249 * @clients: List of detected clients we created (for i2c-core use only) 250 * @flags: A bitmask of flags defined in &enum i2c_driver_flags 251 * 252 * The driver.owner field should be set to the module owner of this driver. 253 * The driver.name field should be set to the name of this driver. 254 * 255 * For automatic device detection, both @detect and @address_list must 256 * be defined. @class should also be set, otherwise only devices forced 257 * with module parameters will be created. The detect function must 258 * fill at least the name field of the i2c_board_info structure it is 259 * handed upon successful detection, and possibly also the flags field. 260 * 261 * If @detect is missing, the driver will still work fine for enumerated 262 * devices. Detected devices simply won't be supported. This is expected 263 * for the many I2C/SMBus devices which can't be detected reliably, and 264 * the ones which can always be enumerated in practice. 265 * 266 * The i2c_client structure which is handed to the @detect callback is 267 * not a real i2c_client. It is initialized just enough so that you can 268 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 269 * else with it. In particular, calling dev_dbg and friends on it is 270 * not allowed. 271 */ 272 struct i2c_driver { 273 unsigned int class; 274 275 /* Standard driver model interfaces */ 276 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id); 277 void (*remove)(struct i2c_client *client); 278 279 /* New driver model interface to aid the seamless removal of the 280 * current probe()'s, more commonly unused than used second parameter. 281 */ 282 int (*probe_new)(struct i2c_client *client); 283 284 /* driver model interfaces that don't relate to enumeration */ 285 void (*shutdown)(struct i2c_client *client); 286 287 /* Alert callback, for example for the SMBus alert protocol. 288 * The format and meaning of the data value depends on the protocol. 289 * For the SMBus alert protocol, there is a single bit of data passed 290 * as the alert response's low bit ("event flag"). 291 * For the SMBus Host Notify protocol, the data corresponds to the 292 * 16-bit payload data reported by the slave device acting as master. 293 */ 294 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 295 unsigned int data); 296 297 /* a ioctl like command that can be used to perform specific functions 298 * with the device. 299 */ 300 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 301 302 struct device_driver driver; 303 const struct i2c_device_id *id_table; 304 305 /* Device detection callback for automatic device creation */ 306 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 307 const unsigned short *address_list; 308 struct list_head clients; 309 310 u32 flags; 311 }; 312 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 313 314 /** 315 * struct i2c_client - represent an I2C slave device 316 * @flags: see I2C_CLIENT_* for possible flags 317 * @addr: Address used on the I2C bus connected to the parent adapter. 318 * @name: Indicates the type of the device, usually a chip name that's 319 * generic enough to hide second-sourcing and compatible revisions. 320 * @adapter: manages the bus segment hosting this I2C device 321 * @dev: Driver model device node for the slave. 322 * @init_irq: IRQ that was set at initialization 323 * @irq: indicates the IRQ generated by this device (if any) 324 * @detected: member of an i2c_driver.clients list or i2c-core's 325 * userspace_devices list 326 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 327 * calls it to pass on slave events to the slave driver. 328 * @devres_group_id: id of the devres group that will be created for resources 329 * acquired when probing this device. 330 * 331 * An i2c_client identifies a single device (i.e. chip) connected to an 332 * i2c bus. The behaviour exposed to Linux is defined by the driver 333 * managing the device. 334 */ 335 struct i2c_client { 336 unsigned short flags; /* div., see below */ 337 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 338 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 339 /* Must equal I2C_M_TEN below */ 340 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 341 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 342 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 343 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 344 /* Must match I2C_M_STOP|IGNORE_NAK */ 345 346 unsigned short addr; /* chip address - NOTE: 7bit */ 347 /* addresses are stored in the */ 348 /* _LOWER_ 7 bits */ 349 char name[I2C_NAME_SIZE]; 350 struct i2c_adapter *adapter; /* the adapter we sit on */ 351 struct device dev; /* the device structure */ 352 int init_irq; /* irq set at initialization */ 353 int irq; /* irq issued by device */ 354 struct list_head detected; 355 #if IS_ENABLED(CONFIG_I2C_SLAVE) 356 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 357 #endif 358 void *devres_group_id; /* ID of probe devres group */ 359 }; 360 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 361 362 struct i2c_adapter *i2c_verify_adapter(struct device *dev); 363 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 364 const struct i2c_client *client); 365 366 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 367 { 368 struct device * const dev = kobj_to_dev(kobj); 369 return to_i2c_client(dev); 370 } 371 372 static inline void *i2c_get_clientdata(const struct i2c_client *client) 373 { 374 return dev_get_drvdata(&client->dev); 375 } 376 377 static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 378 { 379 dev_set_drvdata(&client->dev, data); 380 } 381 382 /* I2C slave support */ 383 384 #if IS_ENABLED(CONFIG_I2C_SLAVE) 385 enum i2c_slave_event { 386 I2C_SLAVE_READ_REQUESTED, 387 I2C_SLAVE_WRITE_REQUESTED, 388 I2C_SLAVE_READ_PROCESSED, 389 I2C_SLAVE_WRITE_RECEIVED, 390 I2C_SLAVE_STOP, 391 }; 392 393 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 394 int i2c_slave_unregister(struct i2c_client *client); 395 bool i2c_detect_slave_mode(struct device *dev); 396 int i2c_slave_event(struct i2c_client *client, 397 enum i2c_slave_event event, u8 *val); 398 #else 399 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 400 #endif 401 402 /** 403 * struct i2c_board_info - template for device creation 404 * @type: chip type, to initialize i2c_client.name 405 * @flags: to initialize i2c_client.flags 406 * @addr: stored in i2c_client.addr 407 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 408 * @platform_data: stored in i2c_client.dev.platform_data 409 * @of_node: pointer to OpenFirmware device node 410 * @fwnode: device node supplied by the platform firmware 411 * @swnode: software node for the device 412 * @resources: resources associated with the device 413 * @num_resources: number of resources in the @resources array 414 * @irq: stored in i2c_client.irq 415 * 416 * I2C doesn't actually support hardware probing, although controllers and 417 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 418 * a device at a given address. Drivers commonly need more information than 419 * that, such as chip type, configuration, associated IRQ, and so on. 420 * 421 * i2c_board_info is used to build tables of information listing I2C devices 422 * that are present. This information is used to grow the driver model tree. 423 * For mainboards this is done statically using i2c_register_board_info(); 424 * bus numbers identify adapters that aren't yet available. For add-on boards, 425 * i2c_new_client_device() does this dynamically with the adapter already known. 426 */ 427 struct i2c_board_info { 428 char type[I2C_NAME_SIZE]; 429 unsigned short flags; 430 unsigned short addr; 431 const char *dev_name; 432 void *platform_data; 433 struct device_node *of_node; 434 struct fwnode_handle *fwnode; 435 const struct software_node *swnode; 436 const struct resource *resources; 437 unsigned int num_resources; 438 int irq; 439 }; 440 441 /** 442 * I2C_BOARD_INFO - macro used to list an i2c device and its address 443 * @dev_type: identifies the device type 444 * @dev_addr: the device's address on the bus. 445 * 446 * This macro initializes essential fields of a struct i2c_board_info, 447 * declaring what has been provided on a particular board. Optional 448 * fields (such as associated irq, or device-specific platform_data) 449 * are provided using conventional syntax. 450 */ 451 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 452 .type = dev_type, .addr = (dev_addr) 453 454 455 #if IS_ENABLED(CONFIG_I2C) 456 /* 457 * Add-on boards should register/unregister their devices; e.g. a board 458 * with integrated I2C, a config eeprom, sensors, and a codec that's 459 * used in conjunction with the primary hardware. 460 */ 461 struct i2c_client * 462 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 463 464 /* If you don't know the exact address of an I2C device, use this variant 465 * instead, which can probe for device presence in a list of possible 466 * addresses. The "probe" callback function is optional. If it is provided, 467 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 468 * a default probing method is used. 469 */ 470 struct i2c_client * 471 i2c_new_scanned_device(struct i2c_adapter *adap, 472 struct i2c_board_info *info, 473 unsigned short const *addr_list, 474 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 475 476 /* Common custom probe functions */ 477 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 478 479 struct i2c_client * 480 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 481 482 struct i2c_client * 483 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 484 485 struct i2c_client * 486 i2c_new_ancillary_device(struct i2c_client *client, 487 const char *name, 488 u16 default_addr); 489 490 void i2c_unregister_device(struct i2c_client *client); 491 492 struct i2c_client *i2c_verify_client(struct device *dev); 493 #else 494 static inline struct i2c_client *i2c_verify_client(struct device *dev) 495 { 496 return NULL; 497 } 498 #endif /* I2C */ 499 500 /* Mainboard arch_initcall() code should register all its I2C devices. 501 * This is done at arch_initcall time, before declaring any i2c adapters. 502 * Modules for add-on boards must use other calls. 503 */ 504 #ifdef CONFIG_I2C_BOARDINFO 505 int 506 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 507 unsigned n); 508 #else 509 static inline int 510 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 511 unsigned n) 512 { 513 return 0; 514 } 515 #endif /* I2C_BOARDINFO */ 516 517 /** 518 * struct i2c_algorithm - represent I2C transfer method 519 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 520 * defined by the msgs array, with num messages available to transfer via 521 * the adapter specified by adap. 522 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 523 * so e.g. PMICs can be accessed very late before shutdown. Optional. 524 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 525 * is not present, then the bus layer will try and convert the SMBus calls 526 * into I2C transfers instead. 527 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 528 * so e.g. PMICs can be accessed very late before shutdown. Optional. 529 * @functionality: Return the flags that this algorithm/adapter pair supports 530 * from the ``I2C_FUNC_*`` flags. 531 * @reg_slave: Register given client to I2C slave mode of this adapter 532 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 533 * 534 * The following structs are for those who like to implement new bus drivers: 535 * i2c_algorithm is the interface to a class of hardware solutions which can 536 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 537 * to name two of the most common. 538 * 539 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 540 * type of error code that occurred during the transfer, as documented in the 541 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the 542 * number of messages executed should be returned. 543 */ 544 struct i2c_algorithm { 545 /* 546 * If an adapter algorithm can't do I2C-level access, set master_xfer 547 * to NULL. If an adapter algorithm can do SMBus access, set 548 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 549 * using common I2C messages. 550 * 551 * master_xfer should return the number of messages successfully 552 * processed, or a negative value on error 553 */ 554 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 555 int num); 556 int (*master_xfer_atomic)(struct i2c_adapter *adap, 557 struct i2c_msg *msgs, int num); 558 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 559 unsigned short flags, char read_write, 560 u8 command, int size, union i2c_smbus_data *data); 561 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 562 unsigned short flags, char read_write, 563 u8 command, int size, union i2c_smbus_data *data); 564 565 /* To determine what the adapter supports */ 566 u32 (*functionality)(struct i2c_adapter *adap); 567 568 #if IS_ENABLED(CONFIG_I2C_SLAVE) 569 int (*reg_slave)(struct i2c_client *client); 570 int (*unreg_slave)(struct i2c_client *client); 571 #endif 572 }; 573 574 /** 575 * struct i2c_lock_operations - represent I2C locking operations 576 * @lock_bus: Get exclusive access to an I2C bus segment 577 * @trylock_bus: Try to get exclusive access to an I2C bus segment 578 * @unlock_bus: Release exclusive access to an I2C bus segment 579 * 580 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 581 */ 582 struct i2c_lock_operations { 583 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 584 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 585 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 586 }; 587 588 /** 589 * struct i2c_timings - I2C timing information 590 * @bus_freq_hz: the bus frequency in Hz 591 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 592 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 593 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 594 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 595 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 596 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 597 * digital filter can filter out 598 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 599 * analog filter 600 */ 601 struct i2c_timings { 602 u32 bus_freq_hz; 603 u32 scl_rise_ns; 604 u32 scl_fall_ns; 605 u32 scl_int_delay_ns; 606 u32 sda_fall_ns; 607 u32 sda_hold_ns; 608 u32 digital_filter_width_ns; 609 u32 analog_filter_cutoff_freq_hz; 610 }; 611 612 /** 613 * struct i2c_bus_recovery_info - I2C bus recovery information 614 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 615 * i2c_generic_scl_recovery(). 616 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 617 * recovery. Populated internally for generic GPIO recovery. 618 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 619 * Populated internally for generic GPIO recovery. 620 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 621 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 622 * GPIO, for generic GPIO recovery. 623 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 624 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 625 * for generic GPIO recovery. 626 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 627 * has a more complex internal logic than just reading SDA. Optional. 628 * @prepare_recovery: This will be called before starting recovery. Platform may 629 * configure padmux here for SDA/SCL line or something else they want. 630 * @unprepare_recovery: This will be called after completing recovery. Platform 631 * may configure padmux here for SDA/SCL line or something else they want. 632 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 633 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 634 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 635 * Optional. 636 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 637 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 638 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 639 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 640 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 641 * is called "gpio" or "recovery" and pinctrl is valid. 642 */ 643 struct i2c_bus_recovery_info { 644 int (*recover_bus)(struct i2c_adapter *adap); 645 646 int (*get_scl)(struct i2c_adapter *adap); 647 void (*set_scl)(struct i2c_adapter *adap, int val); 648 int (*get_sda)(struct i2c_adapter *adap); 649 void (*set_sda)(struct i2c_adapter *adap, int val); 650 int (*get_bus_free)(struct i2c_adapter *adap); 651 652 void (*prepare_recovery)(struct i2c_adapter *adap); 653 void (*unprepare_recovery)(struct i2c_adapter *adap); 654 655 /* gpio recovery */ 656 struct gpio_desc *scl_gpiod; 657 struct gpio_desc *sda_gpiod; 658 struct pinctrl *pinctrl; 659 struct pinctrl_state *pins_default; 660 struct pinctrl_state *pins_gpio; 661 }; 662 663 int i2c_recover_bus(struct i2c_adapter *adap); 664 665 /* Generic recovery routines */ 666 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 667 668 /** 669 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 670 * @flags: see I2C_AQ_* for possible flags and read below 671 * @max_num_msgs: maximum number of messages per transfer 672 * @max_write_len: maximum length of a write message 673 * @max_read_len: maximum length of a read message 674 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 675 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 676 * 677 * Note about combined messages: Some I2C controllers can only send one message 678 * per transfer, plus something called combined message or write-then-read. 679 * This is (usually) a small write message followed by a read message and 680 * barely enough to access register based devices like EEPROMs. There is a flag 681 * to support this mode. It implies max_num_msg = 2 and does the length checks 682 * with max_comb_*_len because combined message mode usually has its own 683 * limitations. Because of HW implementations, some controllers can actually do 684 * write-then-anything or other variants. To support that, write-then-read has 685 * been broken out into smaller bits like write-first and read-second which can 686 * be combined as needed. 687 */ 688 689 struct i2c_adapter_quirks { 690 u64 flags; 691 int max_num_msgs; 692 u16 max_write_len; 693 u16 max_read_len; 694 u16 max_comb_1st_msg_len; 695 u16 max_comb_2nd_msg_len; 696 }; 697 698 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 699 #define I2C_AQ_COMB BIT(0) 700 /* first combined message must be write */ 701 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 702 /* second combined message must be read */ 703 #define I2C_AQ_COMB_READ_SECOND BIT(2) 704 /* both combined messages must have the same target address */ 705 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 706 /* convenience macro for typical write-then read case */ 707 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 708 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 709 /* clock stretching is not supported */ 710 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 711 /* message cannot have length of 0 */ 712 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 713 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 714 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 715 /* adapter cannot do repeated START */ 716 #define I2C_AQ_NO_REP_START BIT(7) 717 718 /* 719 * i2c_adapter is the structure used to identify a physical i2c bus along 720 * with the access algorithms necessary to access it. 721 */ 722 struct i2c_adapter { 723 struct module *owner; 724 unsigned int class; /* classes to allow probing for */ 725 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 726 void *algo_data; 727 728 /* data fields that are valid for all devices */ 729 const struct i2c_lock_operations *lock_ops; 730 struct rt_mutex bus_lock; 731 struct rt_mutex mux_lock; 732 733 int timeout; /* in jiffies */ 734 int retries; 735 struct device dev; /* the adapter device */ 736 unsigned long locked_flags; /* owned by the I2C core */ 737 #define I2C_ALF_IS_SUSPENDED 0 738 #define I2C_ALF_SUSPEND_REPORTED 1 739 740 int nr; 741 char name[48]; 742 struct completion dev_released; 743 744 struct mutex userspace_clients_lock; 745 struct list_head userspace_clients; 746 747 struct i2c_bus_recovery_info *bus_recovery_info; 748 const struct i2c_adapter_quirks *quirks; 749 750 struct irq_domain *host_notify_domain; 751 struct regulator *bus_regulator; 752 }; 753 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 754 755 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 756 { 757 return dev_get_drvdata(&adap->dev); 758 } 759 760 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 761 { 762 dev_set_drvdata(&adap->dev, data); 763 } 764 765 static inline struct i2c_adapter * 766 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 767 { 768 #if IS_ENABLED(CONFIG_I2C_MUX) 769 struct device *parent = adapter->dev.parent; 770 771 if (parent != NULL && parent->type == &i2c_adapter_type) 772 return to_i2c_adapter(parent); 773 else 774 #endif 775 return NULL; 776 } 777 778 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 779 780 /* Adapter locking functions, exported for shared pin cases */ 781 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 782 #define I2C_LOCK_SEGMENT BIT(1) 783 784 /** 785 * i2c_lock_bus - Get exclusive access to an I2C bus segment 786 * @adapter: Target I2C bus segment 787 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 788 * locks only this branch in the adapter tree 789 */ 790 static inline void 791 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 792 { 793 adapter->lock_ops->lock_bus(adapter, flags); 794 } 795 796 /** 797 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 798 * @adapter: Target I2C bus segment 799 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 800 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 801 * 802 * Return: true if the I2C bus segment is locked, false otherwise 803 */ 804 static inline int 805 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 806 { 807 return adapter->lock_ops->trylock_bus(adapter, flags); 808 } 809 810 /** 811 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 812 * @adapter: Target I2C bus segment 813 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 814 * unlocks only this branch in the adapter tree 815 */ 816 static inline void 817 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 818 { 819 adapter->lock_ops->unlock_bus(adapter, flags); 820 } 821 822 /** 823 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 824 * @adap: Adapter to mark as suspended 825 * 826 * When using this helper to mark an adapter as suspended, the core will reject 827 * further transfers to this adapter. The usage of this helper is optional but 828 * recommended for devices having distinct handlers for system suspend and 829 * runtime suspend. More complex devices are free to implement custom solutions 830 * to reject transfers when suspended. 831 */ 832 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 833 { 834 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 835 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 836 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 837 } 838 839 /** 840 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 841 * @adap: Adapter to mark as resumed 842 * 843 * When using this helper to mark an adapter as resumed, the core will allow 844 * further transfers to this adapter. See also further notes to 845 * @i2c_mark_adapter_suspended(). 846 */ 847 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 848 { 849 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 850 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 851 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 852 } 853 854 /* i2c adapter classes (bitmask) */ 855 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 856 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 857 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 858 /* Warn users that the adapter doesn't support classes anymore */ 859 #define I2C_CLASS_DEPRECATED (1<<8) 860 861 /* Internal numbers to terminate lists */ 862 #define I2C_CLIENT_END 0xfffeU 863 864 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 865 #define I2C_ADDRS(addr, addrs...) \ 866 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 867 868 869 /* ----- functions exported by i2c.o */ 870 871 /* administration... 872 */ 873 #if IS_ENABLED(CONFIG_I2C) 874 int i2c_add_adapter(struct i2c_adapter *adap); 875 int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); 876 void i2c_del_adapter(struct i2c_adapter *adap); 877 int i2c_add_numbered_adapter(struct i2c_adapter *adap); 878 879 int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 880 void i2c_del_driver(struct i2c_driver *driver); 881 882 /* use a define to avoid include chaining to get THIS_MODULE */ 883 #define i2c_add_driver(driver) \ 884 i2c_register_driver(THIS_MODULE, driver) 885 886 static inline bool i2c_client_has_driver(struct i2c_client *client) 887 { 888 return !IS_ERR_OR_NULL(client) && client->dev.driver; 889 } 890 891 /* call the i2c_client->command() of all attached clients with 892 * the given arguments */ 893 void i2c_clients_command(struct i2c_adapter *adap, 894 unsigned int cmd, void *arg); 895 896 struct i2c_adapter *i2c_get_adapter(int nr); 897 void i2c_put_adapter(struct i2c_adapter *adap); 898 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 899 900 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 901 902 /* Return the functionality mask */ 903 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 904 { 905 return adap->algo->functionality(adap); 906 } 907 908 /* Return 1 if adapter supports everything we need, 0 if not. */ 909 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 910 { 911 return (func & i2c_get_functionality(adap)) == func; 912 } 913 914 /** 915 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 916 * @adap: i2c adapter 917 * @quirks: quirk flags 918 * 919 * Return: true if the adapter has all the specified quirk flags, false if not 920 */ 921 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 922 { 923 if (!adap->quirks) 924 return false; 925 return (adap->quirks->flags & quirks) == quirks; 926 } 927 928 /* Return the adapter number for a specific adapter */ 929 static inline int i2c_adapter_id(struct i2c_adapter *adap) 930 { 931 return adap->nr; 932 } 933 934 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 935 { 936 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 937 } 938 939 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 940 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 941 942 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 943 /** 944 * module_i2c_driver() - Helper macro for registering a modular I2C driver 945 * @__i2c_driver: i2c_driver struct 946 * 947 * Helper macro for I2C drivers which do not do anything special in module 948 * init/exit. This eliminates a lot of boilerplate. Each module may only 949 * use this macro once, and calling it replaces module_init() and module_exit() 950 */ 951 #define module_i2c_driver(__i2c_driver) \ 952 module_driver(__i2c_driver, i2c_add_driver, \ 953 i2c_del_driver) 954 955 /** 956 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 957 * @__i2c_driver: i2c_driver struct 958 * 959 * Helper macro for I2C drivers which do not do anything special in their 960 * init. This eliminates a lot of boilerplate. Each driver may only 961 * use this macro once, and calling it replaces device_initcall(). 962 */ 963 #define builtin_i2c_driver(__i2c_driver) \ 964 builtin_driver(__i2c_driver, i2c_add_driver) 965 966 #endif /* I2C */ 967 968 #if IS_ENABLED(CONFIG_OF) 969 /* must call put_device() when done with returned i2c_client device */ 970 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 971 972 /* must call put_device() when done with returned i2c_adapter device */ 973 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 974 975 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 976 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 977 978 const struct of_device_id 979 *i2c_of_match_device(const struct of_device_id *matches, 980 struct i2c_client *client); 981 982 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 983 struct i2c_board_info *info); 984 985 #else 986 987 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 988 { 989 return NULL; 990 } 991 992 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 993 { 994 return NULL; 995 } 996 997 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 998 { 999 return NULL; 1000 } 1001 1002 static inline const struct of_device_id 1003 *i2c_of_match_device(const struct of_device_id *matches, 1004 struct i2c_client *client) 1005 { 1006 return NULL; 1007 } 1008 1009 static inline int of_i2c_get_board_info(struct device *dev, 1010 struct device_node *node, 1011 struct i2c_board_info *info) 1012 { 1013 return -ENOTSUPP; 1014 } 1015 1016 #endif /* CONFIG_OF */ 1017 1018 struct acpi_resource; 1019 struct acpi_resource_i2c_serialbus; 1020 1021 #if IS_ENABLED(CONFIG_ACPI) 1022 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1023 struct acpi_resource_i2c_serialbus **i2c); 1024 int i2c_acpi_client_count(struct acpi_device *adev); 1025 u32 i2c_acpi_find_bus_speed(struct device *dev); 1026 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode, 1027 int index, 1028 struct i2c_board_info *info); 1029 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 1030 bool i2c_acpi_waive_d0_probe(struct device *dev); 1031 #else 1032 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1033 struct acpi_resource_i2c_serialbus **i2c) 1034 { 1035 return false; 1036 } 1037 static inline int i2c_acpi_client_count(struct acpi_device *adev) 1038 { 1039 return 0; 1040 } 1041 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1042 { 1043 return 0; 1044 } 1045 static inline struct i2c_client *i2c_acpi_new_device_by_fwnode( 1046 struct fwnode_handle *fwnode, int index, 1047 struct i2c_board_info *info) 1048 { 1049 return ERR_PTR(-ENODEV); 1050 } 1051 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1052 { 1053 return NULL; 1054 } 1055 static inline bool i2c_acpi_waive_d0_probe(struct device *dev) 1056 { 1057 return false; 1058 } 1059 #endif /* CONFIG_ACPI */ 1060 1061 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1062 int index, 1063 struct i2c_board_info *info) 1064 { 1065 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info); 1066 } 1067 1068 #endif /* _LINUX_I2C_H */ 1069