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