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/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 const struct bus_type i2c_bus_type; 27 extern const struct device_type i2c_adapter_type; 28 extern const struct device_type i2c_client_type; 29 30 /* --- General options ------------------------------------------------ */ 31 32 struct i2c_msg; 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 const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client); 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 239 * @remove: Callback for device unbinding 240 * @shutdown: Callback for device shutdown 241 * @alert: Alert callback, for example for the SMBus alert protocol 242 * @command: Callback for bus-wide signaling (optional) 243 * @driver: Device driver model driver 244 * @id_table: List of I2C devices supported by this driver 245 * @detect: Callback for device detection 246 * @address_list: The I2C addresses to probe (for detect) 247 * @flags: A bitmask of flags defined in &enum i2c_driver_flags 248 * 249 * The driver.owner field should be set to the module owner of this driver. 250 * The driver.name field should be set to the name of this driver. 251 * 252 * For automatic device detection, both @detect and @address_list must 253 * be defined. @class should also be set, otherwise only devices forced 254 * with module parameters will be created. The detect function must 255 * fill at least the name field of the i2c_board_info structure it is 256 * handed upon successful detection, and possibly also the flags field. 257 * 258 * If @detect is missing, the driver will still work fine for enumerated 259 * devices. Detected devices simply won't be supported. This is expected 260 * for the many I2C/SMBus devices which can't be detected reliably, and 261 * the ones which can always be enumerated in practice. 262 * 263 * The i2c_client structure which is handed to the @detect callback is 264 * not a real i2c_client. It is initialized just enough so that you can 265 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 266 * else with it. In particular, calling dev_dbg and friends on it is 267 * not allowed. 268 */ 269 struct i2c_driver { 270 unsigned int class; 271 272 /* Standard driver model interfaces */ 273 int (*probe)(struct i2c_client *client); 274 void (*remove)(struct i2c_client *client); 275 276 277 /* driver model interfaces that don't relate to enumeration */ 278 void (*shutdown)(struct i2c_client *client); 279 280 /* Alert callback, for example for the SMBus alert protocol. 281 * The format and meaning of the data value depends on the protocol. 282 * For the SMBus alert protocol, there is a single bit of data passed 283 * as the alert response's low bit ("event flag"). 284 * For the SMBus Host Notify protocol, the data corresponds to the 285 * 16-bit payload data reported by the slave device acting as master. 286 */ 287 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, 288 unsigned int data); 289 290 /* a ioctl like command that can be used to perform specific functions 291 * with the device. 292 */ 293 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 294 295 struct device_driver driver; 296 const struct i2c_device_id *id_table; 297 298 /* Device detection callback for automatic device creation */ 299 int (*detect)(struct i2c_client *client, struct i2c_board_info *info); 300 const unsigned short *address_list; 301 302 u32 flags; 303 }; 304 #define to_i2c_driver(d) container_of_const(d, struct i2c_driver, driver) 305 306 /** 307 * struct i2c_client - represent an I2C slave device 308 * @flags: see I2C_CLIENT_* for possible flags 309 * @addr: Address used on the I2C bus connected to the parent adapter. 310 * @name: Indicates the type of the device, usually a chip name that's 311 * generic enough to hide second-sourcing and compatible revisions. 312 * @adapter: manages the bus segment hosting this I2C device 313 * @dev: Driver model device node for the slave. 314 * @init_irq: IRQ that was set at initialization 315 * @irq: indicates the IRQ generated by this device (if any) 316 * @detected: member of an i2c_driver.clients list or i2c-core's 317 * userspace_devices list 318 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 319 * calls it to pass on slave events to the slave driver. 320 * @devres_group_id: id of the devres group that will be created for resources 321 * acquired when probing this device. 322 * @debugfs: pointer to the debugfs subdirectory which the I2C core created 323 * for this client. 324 * 325 * An i2c_client identifies a single device (i.e. chip) connected to an 326 * i2c bus. The behaviour exposed to Linux is defined by the driver 327 * managing the device. 328 */ 329 struct i2c_client { 330 unsigned short flags; /* div., see below */ 331 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 332 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 333 /* Must equal I2C_M_TEN below */ 334 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 335 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 336 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 337 #define I2C_CLIENT_AUTO 0x100 /* client was auto-detected */ 338 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 339 /* Must match I2C_M_STOP|IGNORE_NAK */ 340 341 unsigned short addr; /* chip address - NOTE: 7bit */ 342 /* addresses are stored in the */ 343 /* _LOWER_ 7 bits */ 344 char name[I2C_NAME_SIZE]; 345 struct i2c_adapter *adapter; /* the adapter we sit on */ 346 struct device dev; /* the device structure */ 347 int init_irq; /* irq set at initialization */ 348 int irq; /* irq issued by device */ 349 struct list_head detected; 350 #if IS_ENABLED(CONFIG_I2C_SLAVE) 351 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 352 #endif 353 void *devres_group_id; /* ID of probe devres group */ 354 struct dentry *debugfs; /* per-client debugfs dir */ 355 }; 356 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 357 358 struct i2c_adapter *i2c_verify_adapter(struct device *dev); 359 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 360 const struct i2c_client *client); 361 362 const void *i2c_get_match_data(const struct i2c_client *client); 363 364 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 365 { 366 struct device * const dev = kobj_to_dev(kobj); 367 return to_i2c_client(dev); 368 } 369 370 static inline void *i2c_get_clientdata(const struct i2c_client *client) 371 { 372 return dev_get_drvdata(&client->dev); 373 } 374 375 static inline void i2c_set_clientdata(struct i2c_client *client, void *data) 376 { 377 dev_set_drvdata(&client->dev, data); 378 } 379 380 /* I2C slave support */ 381 382 enum i2c_slave_event { 383 I2C_SLAVE_READ_REQUESTED, 384 I2C_SLAVE_WRITE_REQUESTED, 385 I2C_SLAVE_READ_PROCESSED, 386 I2C_SLAVE_WRITE_RECEIVED, 387 I2C_SLAVE_STOP, 388 }; 389 390 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 391 int i2c_slave_unregister(struct i2c_client *client); 392 int i2c_slave_event(struct i2c_client *client, 393 enum i2c_slave_event event, u8 *val); 394 #if IS_ENABLED(CONFIG_I2C_SLAVE) 395 bool i2c_detect_slave_mode(struct device *dev); 396 #else 397 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 398 #endif 399 400 /** 401 * struct i2c_board_info - template for device creation 402 * @type: chip type, to initialize i2c_client.name 403 * @flags: to initialize i2c_client.flags 404 * @addr: stored in i2c_client.addr 405 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 406 * @platform_data: stored in i2c_client.dev.platform_data 407 * @of_node: pointer to OpenFirmware device node 408 * @fwnode: device node supplied by the platform firmware 409 * @swnode: software node for the device 410 * @resources: resources associated with the device 411 * @num_resources: number of resources in the @resources array 412 * @irq: stored in i2c_client.irq 413 * 414 * I2C doesn't actually support hardware probing, although controllers and 415 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 416 * a device at a given address. Drivers commonly need more information than 417 * that, such as chip type, configuration, associated IRQ, and so on. 418 * 419 * i2c_board_info is used to build tables of information listing I2C devices 420 * that are present. This information is used to grow the driver model tree. 421 * For mainboards this is done statically using i2c_register_board_info(); 422 * bus numbers identify adapters that aren't yet available. For add-on boards, 423 * i2c_new_client_device() does this dynamically with the adapter already known. 424 */ 425 struct i2c_board_info { 426 char type[I2C_NAME_SIZE]; 427 unsigned short flags; 428 unsigned short addr; 429 const char *dev_name; 430 void *platform_data; 431 struct device_node *of_node; 432 struct fwnode_handle *fwnode; 433 const struct software_node *swnode; 434 const struct resource *resources; 435 unsigned int num_resources; 436 int irq; 437 }; 438 439 /** 440 * I2C_BOARD_INFO - macro used to list an i2c device and its address 441 * @dev_type: identifies the device type 442 * @dev_addr: the device's address on the bus. 443 * 444 * This macro initializes essential fields of a struct i2c_board_info, 445 * declaring what has been provided on a particular board. Optional 446 * fields (such as associated irq, or device-specific platform_data) 447 * are provided using conventional syntax. 448 */ 449 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 450 .type = dev_type, .addr = (dev_addr) 451 452 453 #if IS_ENABLED(CONFIG_I2C) 454 /* 455 * Add-on boards should register/unregister their devices; e.g. a board 456 * with integrated I2C, a config eeprom, sensors, and a codec that's 457 * used in conjunction with the primary hardware. 458 */ 459 struct i2c_client * 460 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 461 462 /* If you don't know the exact address of an I2C device, use this variant 463 * instead, which can probe for device presence in a list of possible 464 * addresses. The "probe" callback function is optional. If it is provided, 465 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 466 * a default probing method is used. 467 */ 468 struct i2c_client * 469 i2c_new_scanned_device(struct i2c_adapter *adap, 470 struct i2c_board_info *info, 471 unsigned short const *addr_list, 472 int (*probe)(struct i2c_adapter *adap, unsigned short addr)); 473 474 /* Common custom probe functions */ 475 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr); 476 477 struct i2c_client * 478 i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address); 479 480 struct i2c_client * 481 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 482 483 struct i2c_client * 484 i2c_new_ancillary_device(struct i2c_client *client, 485 const char *name, 486 u16 default_addr); 487 488 void i2c_unregister_device(struct i2c_client *client); 489 490 struct i2c_client *i2c_verify_client(struct device *dev); 491 #else 492 static inline struct i2c_client *i2c_verify_client(struct device *dev) 493 { 494 return NULL; 495 } 496 #endif /* I2C */ 497 498 /* Mainboard arch_initcall() code should register all its I2C devices. 499 * This is done at arch_initcall time, before declaring any i2c adapters. 500 * Modules for add-on boards must use other calls. 501 */ 502 #ifdef CONFIG_I2C_BOARDINFO 503 int 504 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 505 unsigned n); 506 #else 507 static inline int 508 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 509 unsigned n) 510 { 511 return 0; 512 } 513 #endif /* I2C_BOARDINFO */ 514 515 /** 516 * struct i2c_algorithm - represent I2C transfer methods 517 * @xfer: Transfer a given number of messages defined by the msgs array via 518 * the specified adapter. 519 * @xfer_atomic: Same as @xfer. Yet, only using atomic context so e.g. PMICs 520 * can be accessed very late before shutdown. Optional. 521 * @smbus_xfer: Issue SMBus transactions to the given I2C adapter. If this 522 * is not present, then the bus layer will try and convert the SMBus calls 523 * into I2C transfers instead. 524 * @smbus_xfer_atomic: Same as @smbus_xfer. Yet, only using atomic context 525 * so e.g. PMICs can be accessed very late before shutdown. Optional. 526 * @functionality: Return the flags that this algorithm/adapter pair supports 527 * from the ``I2C_FUNC_*`` flags. 528 * @reg_target: Register given client to local target mode of this adapter 529 * @unreg_target: Unregister given client from local target mode of this adapter 530 * 531 * @master_xfer: deprecated, use @xfer 532 * @master_xfer_atomic: deprecated, use @xfer_atomic 533 * @reg_slave: deprecated, use @reg_target 534 * @unreg_slave: deprecated, use @unreg_target 535 * 536 * i2c_algorithm is the interface to a class of hardware solutions which can 537 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 538 * to name two of the most common. 539 * 540 * The return codes from the ``xfer{_atomic}`` fields should indicate the 541 * type of error code that occurred during the transfer, as documented in the 542 * Kernel Documentation file Documentation/i2c/fault-codes.rst. Otherwise, the 543 * number of messages executed should be returned. 544 */ 545 struct i2c_algorithm { 546 /* 547 * If an adapter algorithm can't do I2C-level access, set xfer 548 * to NULL. If an adapter algorithm can do SMBus access, set 549 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 550 * using common I2C messages. 551 */ 552 union { 553 int (*xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 554 int num); 555 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 556 int num); 557 }; 558 union { 559 int (*xfer_atomic)(struct i2c_adapter *adap, 560 struct i2c_msg *msgs, int num); 561 int (*master_xfer_atomic)(struct i2c_adapter *adap, 562 struct i2c_msg *msgs, int num); 563 }; 564 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 565 unsigned short flags, char read_write, 566 u8 command, int size, union i2c_smbus_data *data); 567 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 568 unsigned short flags, char read_write, 569 u8 command, int size, union i2c_smbus_data *data); 570 571 /* To determine what the adapter supports */ 572 u32 (*functionality)(struct i2c_adapter *adap); 573 574 #if IS_ENABLED(CONFIG_I2C_SLAVE) 575 union { 576 int (*reg_target)(struct i2c_client *client); 577 int (*reg_slave)(struct i2c_client *client); 578 }; 579 union { 580 int (*unreg_target)(struct i2c_client *client); 581 int (*unreg_slave)(struct i2c_client *client); 582 }; 583 #endif 584 }; 585 586 /** 587 * struct i2c_lock_operations - represent I2C locking operations 588 * @lock_bus: Get exclusive access to an I2C bus segment 589 * @trylock_bus: Try to get exclusive access to an I2C bus segment 590 * @unlock_bus: Release exclusive access to an I2C bus segment 591 * 592 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 593 */ 594 struct i2c_lock_operations { 595 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags); 596 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags); 597 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags); 598 }; 599 600 /** 601 * struct i2c_timings - I2C timing information 602 * @bus_freq_hz: the bus frequency in Hz 603 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 604 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 605 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 606 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 607 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 608 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core 609 * digital filter can filter out 610 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core 611 * analog filter 612 */ 613 struct i2c_timings { 614 u32 bus_freq_hz; 615 u32 scl_rise_ns; 616 u32 scl_fall_ns; 617 u32 scl_int_delay_ns; 618 u32 sda_fall_ns; 619 u32 sda_hold_ns; 620 u32 digital_filter_width_ns; 621 u32 analog_filter_cutoff_freq_hz; 622 }; 623 624 /** 625 * struct i2c_bus_recovery_info - I2C bus recovery information 626 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 627 * i2c_generic_scl_recovery(). 628 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 629 * recovery. Populated internally for generic GPIO recovery. 630 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 631 * Populated internally for generic GPIO recovery. 632 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 633 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 634 * GPIO, for generic GPIO recovery. 635 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 636 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 637 * for generic GPIO recovery. 638 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 639 * has a more complex internal logic than just reading SDA. Optional. 640 * @prepare_recovery: This will be called before starting recovery. Platform may 641 * configure padmux here for SDA/SCL line or something else they want. 642 * @unprepare_recovery: This will be called after completing recovery. Platform 643 * may configure padmux here for SDA/SCL line or something else they want. 644 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 645 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 646 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins. 647 * Optional. 648 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned 649 * to the I2C bus. Optional. Populated internally for GPIO recovery, if 650 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid. 651 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as 652 * GPIOs. Optional. Populated internally for GPIO recovery, if this state 653 * is called "gpio" or "recovery" and pinctrl is valid. 654 */ 655 struct i2c_bus_recovery_info { 656 int (*recover_bus)(struct i2c_adapter *adap); 657 658 int (*get_scl)(struct i2c_adapter *adap); 659 void (*set_scl)(struct i2c_adapter *adap, int val); 660 int (*get_sda)(struct i2c_adapter *adap); 661 void (*set_sda)(struct i2c_adapter *adap, int val); 662 int (*get_bus_free)(struct i2c_adapter *adap); 663 664 void (*prepare_recovery)(struct i2c_adapter *adap); 665 void (*unprepare_recovery)(struct i2c_adapter *adap); 666 667 /* gpio recovery */ 668 struct gpio_desc *scl_gpiod; 669 struct gpio_desc *sda_gpiod; 670 struct pinctrl *pinctrl; 671 struct pinctrl_state *pins_default; 672 struct pinctrl_state *pins_gpio; 673 }; 674 675 int i2c_recover_bus(struct i2c_adapter *adap); 676 677 /* Generic recovery routines */ 678 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 679 680 /** 681 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 682 * @flags: see I2C_AQ_* for possible flags and read below 683 * @max_num_msgs: maximum number of messages per transfer 684 * @max_write_len: maximum length of a write message 685 * @max_read_len: maximum length of a read message 686 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 687 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 688 * 689 * Note about combined messages: Some I2C controllers can only send one message 690 * per transfer, plus something called combined message or write-then-read. 691 * This is (usually) a small write message followed by a read message and 692 * barely enough to access register based devices like EEPROMs. There is a flag 693 * to support this mode. It implies max_num_msg = 2 and does the length checks 694 * with max_comb_*_len because combined message mode usually has its own 695 * limitations. Because of HW implementations, some controllers can actually do 696 * write-then-anything or other variants. To support that, write-then-read has 697 * been broken out into smaller bits like write-first and read-second which can 698 * be combined as needed. 699 */ 700 701 struct i2c_adapter_quirks { 702 u64 flags; 703 int max_num_msgs; 704 u16 max_write_len; 705 u16 max_read_len; 706 u16 max_comb_1st_msg_len; 707 u16 max_comb_2nd_msg_len; 708 }; 709 710 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 711 #define I2C_AQ_COMB BIT(0) 712 /* first combined message must be write */ 713 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 714 /* second combined message must be read */ 715 #define I2C_AQ_COMB_READ_SECOND BIT(2) 716 /* both combined messages must have the same target address */ 717 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 718 /* convenience macro for typical write-then read case */ 719 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 720 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 721 /* clock stretching is not supported */ 722 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 723 /* message cannot have length of 0 */ 724 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 725 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 726 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 727 /* adapter cannot do repeated START */ 728 #define I2C_AQ_NO_REP_START BIT(7) 729 730 /* 731 * i2c_adapter is the structure used to identify a physical i2c bus along 732 * with the access algorithms necessary to access it. 733 */ 734 struct i2c_adapter { 735 struct module *owner; 736 unsigned int class; /* classes to allow probing for */ 737 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 738 void *algo_data; 739 740 /* data fields that are valid for all devices */ 741 const struct i2c_lock_operations *lock_ops; 742 struct rt_mutex bus_lock; 743 struct rt_mutex mux_lock; 744 745 int timeout; /* in jiffies */ 746 int retries; 747 struct device dev; /* the adapter device */ 748 unsigned long locked_flags; /* owned by the I2C core */ 749 #define I2C_ALF_IS_SUSPENDED 0 750 #define I2C_ALF_SUSPEND_REPORTED 1 751 752 int nr; 753 char name[48]; 754 struct completion dev_released; 755 756 struct mutex userspace_clients_lock; 757 struct list_head userspace_clients; 758 759 struct i2c_bus_recovery_info *bus_recovery_info; 760 const struct i2c_adapter_quirks *quirks; 761 762 struct irq_domain *host_notify_domain; 763 struct regulator *bus_regulator; 764 765 struct dentry *debugfs; 766 767 /* 7bit address space */ 768 DECLARE_BITMAP(addrs_in_instantiation, 1 << 7); 769 }; 770 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 771 772 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap) 773 { 774 return dev_get_drvdata(&adap->dev); 775 } 776 777 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data) 778 { 779 dev_set_drvdata(&adap->dev, data); 780 } 781 782 static inline struct i2c_adapter * 783 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 784 { 785 #if IS_ENABLED(CONFIG_I2C_MUX) 786 struct device *parent = adapter->dev.parent; 787 788 if (parent != NULL && parent->type == &i2c_adapter_type) 789 return to_i2c_adapter(parent); 790 else 791 #endif 792 return NULL; 793 } 794 795 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)); 796 797 /* Adapter locking functions, exported for shared pin cases */ 798 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 799 #define I2C_LOCK_SEGMENT BIT(1) 800 801 /** 802 * i2c_lock_bus - Get exclusive access to an I2C bus segment 803 * @adapter: Target I2C bus segment 804 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 805 * locks only this branch in the adapter tree 806 */ 807 static inline void 808 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 809 { 810 adapter->lock_ops->lock_bus(adapter, flags); 811 } 812 813 /** 814 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 815 * @adapter: Target I2C bus segment 816 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 817 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 818 * 819 * Return: true if the I2C bus segment is locked, false otherwise 820 */ 821 static inline int 822 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 823 { 824 return adapter->lock_ops->trylock_bus(adapter, flags); 825 } 826 827 /** 828 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 829 * @adapter: Target I2C bus segment 830 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 831 * unlocks only this branch in the adapter tree 832 */ 833 static inline void 834 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 835 { 836 adapter->lock_ops->unlock_bus(adapter, flags); 837 } 838 839 /** 840 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 841 * @adap: Adapter to mark as suspended 842 * 843 * When using this helper to mark an adapter as suspended, the core will reject 844 * further transfers to this adapter. The usage of this helper is optional but 845 * recommended for devices having distinct handlers for system suspend and 846 * runtime suspend. More complex devices are free to implement custom solutions 847 * to reject transfers when suspended. 848 */ 849 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 850 { 851 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 852 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 853 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 854 } 855 856 /** 857 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 858 * @adap: Adapter to mark as resumed 859 * 860 * When using this helper to mark an adapter as resumed, the core will allow 861 * further transfers to this adapter. See also further notes to 862 * @i2c_mark_adapter_suspended(). 863 */ 864 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 865 { 866 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 867 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 868 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 869 } 870 871 /* i2c adapter classes (bitmask) */ 872 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 873 /* Warn users that the adapter doesn't support classes anymore */ 874 #define I2C_CLASS_DEPRECATED (1<<8) 875 876 /* Internal numbers to terminate lists */ 877 #define I2C_CLIENT_END 0xfffeU 878 879 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 880 #define I2C_ADDRS(addr, addrs...) \ 881 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 882 883 884 /* ----- functions exported by i2c.o */ 885 886 /* administration... 887 */ 888 #if IS_ENABLED(CONFIG_I2C) 889 int i2c_add_adapter(struct i2c_adapter *adap); 890 int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter); 891 void i2c_del_adapter(struct i2c_adapter *adap); 892 int i2c_add_numbered_adapter(struct i2c_adapter *adap); 893 894 int i2c_register_driver(struct module *owner, struct i2c_driver *driver); 895 void i2c_del_driver(struct i2c_driver *driver); 896 897 /* use a define to avoid include chaining to get THIS_MODULE */ 898 #define i2c_add_driver(driver) \ 899 i2c_register_driver(THIS_MODULE, driver) 900 901 static inline bool i2c_client_has_driver(struct i2c_client *client) 902 { 903 return !IS_ERR_OR_NULL(client) && client->dev.driver; 904 } 905 906 /* call the i2c_client->command() of all attached clients with 907 * the given arguments */ 908 void i2c_clients_command(struct i2c_adapter *adap, 909 unsigned int cmd, void *arg); 910 911 struct i2c_adapter *i2c_get_adapter(int nr); 912 void i2c_put_adapter(struct i2c_adapter *adap); 913 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 914 915 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 916 917 /* Return the functionality mask */ 918 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 919 { 920 return adap->algo->functionality(adap); 921 } 922 923 /* Return 1 if adapter supports everything we need, 0 if not. */ 924 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 925 { 926 return (func & i2c_get_functionality(adap)) == func; 927 } 928 929 /** 930 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 931 * @adap: i2c adapter 932 * @quirks: quirk flags 933 * 934 * Return: true if the adapter has all the specified quirk flags, false if not 935 */ 936 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 937 { 938 if (!adap->quirks) 939 return false; 940 return (adap->quirks->flags & quirks) == quirks; 941 } 942 943 /* Return the adapter number for a specific adapter */ 944 static inline int i2c_adapter_id(struct i2c_adapter *adap) 945 { 946 return adap->nr; 947 } 948 949 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 950 { 951 return (msg->addr << 1) | (msg->flags & I2C_M_RD); 952 } 953 954 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 955 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 956 957 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 958 /** 959 * module_i2c_driver() - Helper macro for registering a modular I2C driver 960 * @__i2c_driver: i2c_driver struct 961 * 962 * Helper macro for I2C drivers which do not do anything special in module 963 * init/exit. This eliminates a lot of boilerplate. Each module may only 964 * use this macro once, and calling it replaces module_init() and module_exit() 965 */ 966 #define module_i2c_driver(__i2c_driver) \ 967 module_driver(__i2c_driver, i2c_add_driver, \ 968 i2c_del_driver) 969 970 /** 971 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 972 * @__i2c_driver: i2c_driver struct 973 * 974 * Helper macro for I2C drivers which do not do anything special in their 975 * init. This eliminates a lot of boilerplate. Each driver may only 976 * use this macro once, and calling it replaces device_initcall(). 977 */ 978 #define builtin_i2c_driver(__i2c_driver) \ 979 builtin_driver(__i2c_driver, i2c_add_driver) 980 981 /* must call put_device() when done with returned i2c_client device */ 982 struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode); 983 984 /* must call put_device() when done with returned i2c_adapter device */ 985 struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode); 986 987 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 988 struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode); 989 990 #else /* I2C */ 991 992 static inline struct i2c_client * 993 i2c_find_device_by_fwnode(struct fwnode_handle *fwnode) 994 { 995 return NULL; 996 } 997 998 static inline struct i2c_adapter * 999 i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode) 1000 { 1001 return NULL; 1002 } 1003 1004 static inline struct i2c_adapter * 1005 i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode) 1006 { 1007 return NULL; 1008 } 1009 1010 #endif /* !I2C */ 1011 1012 #if IS_ENABLED(CONFIG_OF) 1013 /* must call put_device() when done with returned i2c_client device */ 1014 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 1015 { 1016 return i2c_find_device_by_fwnode(of_fwnode_handle(node)); 1017 } 1018 1019 /* must call put_device() when done with returned i2c_adapter device */ 1020 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 1021 { 1022 return i2c_find_adapter_by_fwnode(of_fwnode_handle(node)); 1023 } 1024 1025 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 1026 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 1027 { 1028 return i2c_get_adapter_by_fwnode(of_fwnode_handle(node)); 1029 } 1030 1031 const struct of_device_id 1032 *i2c_of_match_device(const struct of_device_id *matches, 1033 struct i2c_client *client); 1034 1035 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 1036 struct i2c_board_info *info); 1037 1038 #else 1039 1040 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 1041 { 1042 return NULL; 1043 } 1044 1045 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 1046 { 1047 return NULL; 1048 } 1049 1050 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 1051 { 1052 return NULL; 1053 } 1054 1055 static inline const struct of_device_id 1056 *i2c_of_match_device(const struct of_device_id *matches, 1057 struct i2c_client *client) 1058 { 1059 return NULL; 1060 } 1061 1062 static inline int of_i2c_get_board_info(struct device *dev, 1063 struct device_node *node, 1064 struct i2c_board_info *info) 1065 { 1066 return -ENOTSUPP; 1067 } 1068 1069 #endif /* CONFIG_OF */ 1070 1071 struct acpi_resource; 1072 struct acpi_resource_i2c_serialbus; 1073 1074 #if IS_REACHABLE(CONFIG_ACPI) && IS_REACHABLE(CONFIG_I2C) 1075 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1076 struct acpi_resource_i2c_serialbus **i2c); 1077 int i2c_acpi_client_count(struct acpi_device *adev); 1078 u32 i2c_acpi_find_bus_speed(struct device *dev); 1079 struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode, 1080 int index, 1081 struct i2c_board_info *info); 1082 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); 1083 bool i2c_acpi_waive_d0_probe(struct device *dev); 1084 #else 1085 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 1086 struct acpi_resource_i2c_serialbus **i2c) 1087 { 1088 return false; 1089 } 1090 static inline int i2c_acpi_client_count(struct acpi_device *adev) 1091 { 1092 return 0; 1093 } 1094 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 1095 { 1096 return 0; 1097 } 1098 static inline struct i2c_client *i2c_acpi_new_device_by_fwnode( 1099 struct fwnode_handle *fwnode, int index, 1100 struct i2c_board_info *info) 1101 { 1102 return ERR_PTR(-ENODEV); 1103 } 1104 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle) 1105 { 1106 return NULL; 1107 } 1108 static inline bool i2c_acpi_waive_d0_probe(struct device *dev) 1109 { 1110 return false; 1111 } 1112 #endif /* CONFIG_ACPI */ 1113 1114 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 1115 int index, 1116 struct i2c_board_info *info) 1117 { 1118 return i2c_acpi_new_device_by_fwnode(dev_fwnode(dev), index, info); 1119 } 1120 1121 #endif /* _LINUX_I2C_H */ 1122