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