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/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_client *i2c_verify_client(struct device *dev); 349 struct i2c_adapter *i2c_verify_adapter(struct device *dev); 350 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 351 const struct i2c_client *client); 352 353 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 354 { 355 struct device * const dev = kobj_to_dev(kobj); 356 return to_i2c_client(dev); 357 } 358 359 static inline void *i2c_get_clientdata(const struct i2c_client *client) 360 { 361 return dev_get_drvdata(&client->dev); 362 } 363 364 static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 365 { 366 dev_set_drvdata(&client->dev, data); 367 } 368 369 /* I2C slave support */ 370 371 #if IS_ENABLED(CONFIG_I2C_SLAVE) 372 enum i2c_slave_event { 373 I2C_SLAVE_READ_REQUESTED, 374 I2C_SLAVE_WRITE_REQUESTED, 375 I2C_SLAVE_READ_PROCESSED, 376 I2C_SLAVE_WRITE_RECEIVED, 377 I2C_SLAVE_STOP, 378 }; 379 380 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 381 int i2c_slave_unregister(struct i2c_client *client); 382 bool i2c_detect_slave_mode(struct device *dev); 383 384 static inline int i2c_slave_event(struct i2c_client *client, 385 enum i2c_slave_event event, u8 *val) 386 { 387 return client->slave_cb(client, event, val); 388 } 389 #else 390 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 391 #endif 392 393 /** 394 * struct i2c_board_info - template for device creation 395 * @type: chip type, to initialize i2c_client.name 396 * @flags: to initialize i2c_client.flags 397 * @addr: stored in i2c_client.addr 398 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 399 * @platform_data: stored in i2c_client.dev.platform_data 400 * @of_node: pointer to OpenFirmware device node 401 * @fwnode: device node supplied by the platform firmware 402 * @swnode: software node for the device 403 * @resources: resources associated with the device 404 * @num_resources: number of resources in the @resources array 405 * @irq: stored in i2c_client.irq 406 * 407 * I2C doesn't actually support hardware probing, although controllers and 408 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 409 * a device at a given address. Drivers commonly need more information than 410 * that, such as chip type, configuration, associated IRQ, and so on. 411 * 412 * i2c_board_info is used to build tables of information listing I2C devices 413 * that are present. This information is used to grow the driver model tree. 414 * For mainboards this is done statically using i2c_register_board_info(); 415 * bus numbers identify adapters that aren't yet available. For add-on boards, 416 * i2c_new_client_device() does this dynamically with the adapter already known. 417 */ 418 struct i2c_board_info { 419 char type[I2C_NAME_SIZE]; 420 unsigned short flags; 421 unsigned short addr; 422 const char *dev_name; 423 void *platform_data; 424 struct device_node *of_node; 425 struct fwnode_handle *fwnode; 426 const struct software_node *swnode; 427 const struct resource *resources; 428 unsigned int num_resources; 429 int irq; 430 }; 431 432 /** 433 * I2C_BOARD_INFO - macro used to list an i2c device and its address 434 * @dev_type: identifies the device type 435 * @dev_addr: the device's address on the bus. 436 * 437 * This macro initializes essential fields of a struct i2c_board_info, 438 * declaring what has been provided on a particular board. Optional 439 * fields (such as associated irq, or device-specific platform_data) 440 * are provided using conventional syntax. 441 */ 442 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 443 .type = dev_type, .addr = (dev_addr) 444 445 446 #if IS_ENABLED(CONFIG_I2C) 447 /* 448 * Add-on boards should register/unregister their devices; e.g. a board 449 * with integrated I2C, a config eeprom, sensors, and a codec that's 450 * used in conjunction with the primary hardware. 451 */ 452 struct i2c_client * 453 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 454 455 /* If you don't know the exact address of an I2C device, use this variant 456 * instead, which can probe for device presence in a list of possible 457 * addresses. The "probe" callback function is optional. If it is provided, 458 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 459 * a default probing method is used. 460 */ 461 struct i2c_client * 462 i2c_new_scanned_device(struct i2c_adapter *adap, 463 struct i2c_board_info *info, 464 unsigned short const *addr_list, 465 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 466 467 /* Common custom probe functions */ 468 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 469 470 struct i2c_client * 471 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 472 473 struct i2c_client * 474 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 475 476 struct i2c_client * 477 i2c_new_ancillary_device(struct i2c_client *client, 478 const char *name, 479 u16 default_addr); 480 481 void i2c_unregister_device(struct i2c_client *client); 482 #endif /* I2C */ 483 484 /* Mainboard arch_initcall() code should register all its I2C devices. 485 * This is done at arch_initcall time, before declaring any i2c adapters. 486 * Modules for add-on boards must use other calls. 487 */ 488 #ifdef CONFIG_I2C_BOARDINFO 489 int 490 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 491 unsigned n); 492 #else 493 static inline int 494 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 495 unsigned n) 496 { 497 return 0; 498 } 499 #endif /* I2C_BOARDINFO */ 500 501 /** 502 * struct i2c_algorithm - represent I2C transfer method 503 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 504 * defined by the msgs array, with num messages available to transfer via 505 * the adapter specified by adap. 506 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 507 * so e.g. PMICs can be accessed very late before shutdown. Optional. 508 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 509 * is not present, then the bus layer will try and convert the SMBus calls 510 * into I2C transfers instead. 511 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 512 * so e.g. PMICs can be accessed very late before shutdown. Optional. 513 * @functionality: Return the flags that this algorithm/adapter pair supports 514 * from the ``I2C_FUNC_*`` flags. 515 * @reg_slave: Register given client to I2C slave mode of this adapter 516 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 517 * 518 * The following structs are for those who like to implement new bus drivers: 519 * i2c_algorithm is the interface to a class of hardware solutions which can 520 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 521 * to name two of the most common. 522 * 523 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the 524 * type of error code that occurred during the transfer, as documented in the 525 * Kernel Documentation file Documentation/i2c/fault-codes.rst. 526 */ 527 struct i2c_algorithm { 528 /* 529 * If an adapter algorithm can't do I2C-level access, set master_xfer 530 * to NULL. If an adapter algorithm can do SMBus access, set 531 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 532 * using common I2C messages. 533 * 534 * master_xfer should return the number of messages successfully 535 * processed, or a negative value on error 536 */ 537 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 538 int num); 539 int (*master_xfer_atomic)(struct i2c_adapter *adap, 540 struct i2c_msg *msgs, int num); 541 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 542 unsigned short flags, char read_write, 543 u8 command, int size, union i2c_smbus_data *data); 544 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 545 unsigned short flags, char read_write, 546 u8 command, int size, union i2c_smbus_data *data); 547 548 /* To determine what the adapter supports */ 549 u32 (*functionality)(struct i2c_adapter *adap); 550 551 #if IS_ENABLED(CONFIG_I2C_SLAVE) 552 int (*reg_slave)(struct i2c_client *client); 553 int (*unreg_slave)(struct i2c_client *client); 554 #endif 555 }; 556 557 /** 558 * struct i2c_lock_operations - represent I2C locking operations 559 * @lock_bus: Get exclusive access to an I2C bus segment 560 * @trylock_bus: Try to get exclusive access to an I2C bus segment 561 * @unlock_bus: Release exclusive access to an I2C bus segment 562 * 563 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 564 */ 565 struct i2c_lock_operations { 566 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 567 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 568 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 569 }; 570 571 /** 572 * struct i2c_timings - I2C timing information 573 * @bus_freq_hz: the bus frequency in Hz 574 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 575 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 576 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 577 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 578 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 579 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 580 * digital filter can filter out 581 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 582 * analog filter 583 */ 584 struct i2c_timings { 585 u32 bus_freq_hz; 586 u32 scl_rise_ns; 587 u32 scl_fall_ns; 588 u32 scl_int_delay_ns; 589 u32 sda_fall_ns; 590 u32 sda_hold_ns; 591 u32 digital_filter_width_ns; 592 u32 analog_filter_cutoff_freq_hz; 593 }; 594 595 /** 596 * struct i2c_bus_recovery_info - I2C bus recovery information 597 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 598 * i2c_generic_scl_recovery(). 599 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 600 * recovery. Populated internally for generic GPIO recovery. 601 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 602 * Populated internally for generic GPIO recovery. 603 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 604 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 605 * GPIO, for generic GPIO recovery. 606 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 607 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 608 * for generic GPIO recovery. 609 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 610 * has a more complex internal logic than just reading SDA. Optional. 611 * @prepare_recovery: This will be called before starting recovery. Platform may 612 * configure padmux here for SDA/SCL line or something else they want. 613 * @unprepare_recovery: This will be called after completing recovery. Platform 614 * may configure padmux here for SDA/SCL line or something else they want. 615 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 616 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 617 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 618 * Optional. 619 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 620 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 621 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 622 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 623 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 624 * is called "gpio" or "recovery" and pinctrl is valid. 625 */ 626 struct i2c_bus_recovery_info { 627 int (*recover_bus)(struct i2c_adapter *adap); 628 629 int (*get_scl)(struct i2c_adapter *adap); 630 void (*set_scl)(struct i2c_adapter *adap, int val); 631 int (*get_sda)(struct i2c_adapter *adap); 632 void (*set_sda)(struct i2c_adapter *adap, int val); 633 int (*get_bus_free)(struct i2c_adapter *adap); 634 635 void (*prepare_recovery)(struct i2c_adapter *adap); 636 void (*unprepare_recovery)(struct i2c_adapter *adap); 637 638 /* gpio recovery */ 639 struct gpio_desc *scl_gpiod; 640 struct gpio_desc *sda_gpiod; 641 struct pinctrl *pinctrl; 642 struct pinctrl_state *pins_default; 643 struct pinctrl_state *pins_gpio; 644 }; 645 646 int i2c_recover_bus(struct i2c_adapter *adap); 647 648 /* Generic recovery routines */ 649 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 650 651 /** 652 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 653 * @flags: see I2C_AQ_* for possible flags and read below 654 * @max_num_msgs: maximum number of messages per transfer 655 * @max_write_len: maximum length of a write message 656 * @max_read_len: maximum length of a read message 657 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 658 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 659 * 660 * Note about combined messages: Some I2C controllers can only send one message 661 * per transfer, plus something called combined message or write-then-read. 662 * This is (usually) a small write message followed by a read message and 663 * barely enough to access register based devices like EEPROMs. There is a flag 664 * to support this mode. It implies max_num_msg = 2 and does the length checks 665 * with max_comb_*_len because combined message mode usually has its own 666 * limitations. Because of HW implementations, some controllers can actually do 667 * write-then-anything or other variants. To support that, write-then-read has 668 * been broken out into smaller bits like write-first and read-second which can 669 * be combined as needed. 670 */ 671 672 struct i2c_adapter_quirks { 673 u64 flags; 674 int max_num_msgs; 675 u16 max_write_len; 676 u16 max_read_len; 677 u16 max_comb_1st_msg_len; 678 u16 max_comb_2nd_msg_len; 679 }; 680 681 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 682 #define I2C_AQ_COMB BIT(0) 683 /* first combined message must be write */ 684 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 685 /* second combined message must be read */ 686 #define I2C_AQ_COMB_READ_SECOND BIT(2) 687 /* both combined messages must have the same target address */ 688 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 689 /* convenience macro for typical write-then read case */ 690 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 691 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 692 /* clock stretching is not supported */ 693 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 694 /* message cannot have length of 0 */ 695 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 696 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 697 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 698 /* adapter cannot do repeated START */ 699 #define I2C_AQ_NO_REP_START BIT(7) 700 701 /* 702 * i2c_adapter is the structure used to identify a physical i2c bus along 703 * with the access algorithms necessary to access it. 704 */ 705 struct i2c_adapter { 706 struct module *owner; 707 unsigned int class; /* classes to allow probing for */ 708 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 709 void *algo_data; 710 711 /* data fields that are valid for all devices */ 712 const struct i2c_lock_operations *lock_ops; 713 struct rt_mutex bus_lock; 714 struct rt_mutex mux_lock; 715 716 int timeout; /* in jiffies */ 717 int retries; 718 struct device dev; /* the adapter device */ 719 unsigned long locked_flags; /* owned by the I2C core */ 720 #define I2C_ALF_IS_SUSPENDED 0 721 #define I2C_ALF_SUSPEND_REPORTED 1 722 723 int nr; 724 char name[48]; 725 struct completion dev_released; 726 727 struct mutex userspace_clients_lock; 728 struct list_head userspace_clients; 729 730 struct i2c_bus_recovery_info *bus_recovery_info; 731 const struct i2c_adapter_quirks *quirks; 732 733 struct irq_domain *host_notify_domain; 734 struct regulator *bus_regulator; 735 }; 736 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 737 738 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 739 { 740 return dev_get_drvdata(&adap->dev); 741 } 742 743 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 744 { 745 dev_set_drvdata(&adap->dev, data); 746 } 747 748 static inline struct i2c_adapter * 749 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 750 { 751 #if IS_ENABLED(CONFIG_I2C_MUX) 752 struct device *parent = adapter->dev.parent; 753 754 if (parent != NULL && parent->type == &i2c_adapter_type) 755 return to_i2c_adapter(parent); 756 else 757 #endif 758 return NULL; 759 } 760 761 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 762 763 /* Adapter locking functions, exported for shared pin cases */ 764 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 765 #define I2C_LOCK_SEGMENT BIT(1) 766 767 /** 768 * i2c_lock_bus - Get exclusive access to an I2C bus segment 769 * @adapter: Target I2C bus segment 770 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 771 * locks only this branch in the adapter tree 772 */ 773 static inline void 774 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 775 { 776 adapter->lock_ops->lock_bus(adapter, flags); 777 } 778 779 /** 780 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 781 * @adapter: Target I2C bus segment 782 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 783 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 784 * 785 * Return: true if the I2C bus segment is locked, false otherwise 786 */ 787 static inline int 788 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 789 { 790 return adapter->lock_ops->trylock_bus(adapter, flags); 791 } 792 793 /** 794 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 795 * @adapter: Target I2C bus segment 796 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 797 * unlocks only this branch in the adapter tree 798 */ 799 static inline void 800 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 801 { 802 adapter->lock_ops->unlock_bus(adapter, flags); 803 } 804 805 /** 806 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 807 * @adap: Adapter to mark as suspended 808 * 809 * When using this helper to mark an adapter as suspended, the core will reject 810 * further transfers to this adapter. The usage of this helper is optional but 811 * recommended for devices having distinct handlers for system suspend and 812 * runtime suspend. More complex devices are free to implement custom solutions 813 * to reject transfers when suspended. 814 */ 815 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 816 { 817 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 818 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 819 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 820 } 821 822 /** 823 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 824 * @adap: Adapter to mark as resumed 825 * 826 * When using this helper to mark an adapter as resumed, the core will allow 827 * further transfers to this adapter. See also further notes to 828 * @i2c_mark_adapter_suspended(). 829 */ 830 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 831 { 832 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 833 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 834 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 835 } 836 837 /* i2c adapter classes (bitmask) */ 838 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 839 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 840 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 841 /* Warn users that the adapter doesn't support classes anymore */ 842 #define I2C_CLASS_DEPRECATED (1<<8) 843 844 /* Internal numbers to terminate lists */ 845 #define I2C_CLIENT_END 0xfffeU 846 847 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 848 #define I2C_ADDRS(addr, addrs...) \ 849 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 850 851 852 /* ----- functions exported by i2c.o */ 853 854 /* administration... 855 */ 856 #if IS_ENABLED(CONFIG_I2C) 857 int i2c_add_adapter(struct i2c_adapter *adap); 858 int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); 859 void i2c_del_adapter(struct i2c_adapter *adap); 860 int i2c_add_numbered_adapter(struct i2c_adapter *adap); 861 862 int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 863 void i2c_del_driver(struct i2c_driver *driver); 864 865 /* use a define to avoid include chaining to get THIS_MODULE */ 866 #define i2c_add_driver(driver) \ 867 i2c_register_driver(THIS_MODULE, driver) 868 869 static inline bool i2c_client_has_driver(struct i2c_client *client) 870 { 871 return !IS_ERR_OR_NULL(client) && client->dev.driver; 872 } 873 874 /* call the i2c_client->command() of all attached clients with 875 * the given arguments */ 876 void i2c_clients_command(struct i2c_adapter *adap, 877 unsigned int cmd, void *arg); 878 879 struct i2c_adapter *i2c_get_adapter(int nr); 880 void i2c_put_adapter(struct i2c_adapter *adap); 881 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 882 883 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 884 885 /* Return the functionality mask */ 886 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 887 { 888 return adap->algo->functionality(adap); 889 } 890 891 /* Return 1 if adapter supports everything we need, 0 if not. */ 892 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 893 { 894 return (func & i2c_get_functionality(adap)) == func; 895 } 896 897 /** 898 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 899 * @adap: i2c adapter 900 * @quirks: quirk flags 901 * 902 * Return: true if the adapter has all the specified quirk flags, false if not 903 */ 904 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 905 { 906 if (!adap->quirks) 907 return false; 908 return (adap->quirks->flags & quirks) == quirks; 909 } 910 911 /* Return the adapter number for a specific adapter */ 912 static inline int i2c_adapter_id(struct i2c_adapter *adap) 913 { 914 return adap->nr; 915 } 916 917 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 918 { 919 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 920 } 921 922 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 923 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 924 925 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 926 /** 927 * module_i2c_driver() - Helper macro for registering a modular I2C driver 928 * @__i2c_driver: i2c_driver struct 929 * 930 * Helper macro for I2C drivers which do not do anything special in module 931 * init/exit. This eliminates a lot of boilerplate. Each module may only 932 * use this macro once, and calling it replaces module_init() and module_exit() 933 */ 934 #define module_i2c_driver(__i2c_driver) \ 935 module_driver(__i2c_driver, i2c_add_driver, \ 936 i2c_del_driver) 937 938 /** 939 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 940 * @__i2c_driver: i2c_driver struct 941 * 942 * Helper macro for I2C drivers which do not do anything special in their 943 * init. This eliminates a lot of boilerplate. Each driver may only 944 * use this macro once, and calling it replaces device_initcall(). 945 */ 946 #define builtin_i2c_driver(__i2c_driver) \ 947 builtin_driver(__i2c_driver, i2c_add_driver) 948 949 #endif /* I2C */ 950 951 #if IS_ENABLED(CONFIG_OF) 952 /* must call put_device() when done with returned i2c_client device */ 953 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 954 955 /* must call put_device() when done with returned i2c_adapter device */ 956 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 957 958 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 959 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 960 961 const struct of_device_id 962 *i2c_of_match_device(const struct of_device_id *matches, 963 struct i2c_client *client); 964 965 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 966 struct i2c_board_info *info); 967 968 #else 969 970 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 971 { 972 return NULL; 973 } 974 975 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 976 { 977 return NULL; 978 } 979 980 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 981 { 982 return NULL; 983 } 984 985 static inline const struct of_device_id 986 *i2c_of_match_device(const struct of_device_id *matches, 987 struct i2c_client *client) 988 { 989 return NULL; 990 } 991 992 static inline int of_i2c_get_board_info(struct device *dev, 993 struct device_node *node, 994 struct i2c_board_info *info) 995 { 996 return -ENOTSUPP; 997 } 998 999 #endif /* CONFIG_OF */ 1000 1001 struct acpi_resource; 1002 struct acpi_resource_i2c_serialbus; 1003 1004 #if IS_ENABLED(CONFIG_ACPI) 1005 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1006 struct acpi_resource_i2c_serialbus **i2c); 1007 u32 i2c_acpi_find_bus_speed(struct device *dev); 1008 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 1009 struct i2c_board_info *info); 1010 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 1011 #else 1012 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1013 struct acpi_resource_i2c_serialbus **i2c) 1014 { 1015 return false; 1016 } 1017 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1018 { 1019 return 0; 1020 } 1021 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1022 int index, struct i2c_board_info *info) 1023 { 1024 return ERR_PTR(-ENODEV); 1025 } 1026 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1027 { 1028 return NULL; 1029 } 1030 #endif /* CONFIG_ACPI */ 1031 1032 #endif /* _LINUX_I2C_H */ 1033