1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* ------------------------------------------------------------------------- */ 3 /* */ 4 /* i2c.h - definitions for the i2c-bus interface */ 5 /* */ 6 /* ------------------------------------------------------------------------- */ 7 /* Copyright (C) 1995-2000 Simon G. Vogl 8 9 */ 10 /* ------------------------------------------------------------------------- */ 11 12 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and 13 Frodo Looijaard <frodol@dds.nl> */ 14 #ifndef _LINUX_I2C_H 15 #define _LINUX_I2C_H 16 17 #include <linux/mod_devicetable.h> 18 #include <linux/device.h> /* for struct device */ 19 #include <linux/sched.h> /* for completion */ 20 #include <linux/mutex.h> 21 #include <linux/rtmutex.h> 22 #include <linux/irqdomain.h> /* for Host Notify IRQ */ 23 #include <linux/of.h> /* for struct device_node */ 24 #include <linux/swab.h> /* for swab16 */ 25 #include <uapi/linux/i2c.h> 26 27 extern struct bus_type i2c_bus_type; 28 extern struct device_type i2c_adapter_type; 29 extern struct device_type i2c_client_type; 30 31 /* --- General options ------------------------------------------------ */ 32 33 struct i2c_msg; 34 struct i2c_algorithm; 35 struct i2c_adapter; 36 struct i2c_client; 37 struct i2c_driver; 38 struct i2c_device_identity; 39 union i2c_smbus_data; 40 struct i2c_board_info; 41 enum i2c_slave_event; 42 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 43 44 struct module; 45 struct property_entry; 46 47 #if IS_ENABLED(CONFIG_I2C) 48 /* 49 * The master routines are the ones normally used to transmit data to devices 50 * on a bus (or read from them). Apart from two basic transfer functions to 51 * transmit one message at a time, a more complex version can be used to 52 * transmit an arbitrary number of messages without interruption. 53 * @count must be be less than 64k since msg.len is u16. 54 */ 55 extern int i2c_transfer_buffer_flags(const struct i2c_client *client, 56 char *buf, int count, u16 flags); 57 58 /** 59 * i2c_master_recv - issue a single I2C message in master receive mode 60 * @client: Handle to slave device 61 * @buf: Where to store data read from slave 62 * @count: How many bytes to read, must be less than 64k since msg.len is u16 63 * 64 * Returns negative errno, or else the number of bytes read. 65 */ 66 static inline int i2c_master_recv(const struct i2c_client *client, 67 char *buf, int count) 68 { 69 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 70 }; 71 72 /** 73 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 74 * using a DMA safe buffer 75 * @client: Handle to slave device 76 * @buf: Where to store data read from slave, must be safe to use with DMA 77 * @count: How many bytes to read, must be less than 64k since msg.len is u16 78 * 79 * Returns negative errno, or else the number of bytes read. 80 */ 81 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 82 char *buf, int count) 83 { 84 return i2c_transfer_buffer_flags(client, buf, count, 85 I2C_M_RD | I2C_M_DMA_SAFE); 86 }; 87 88 /** 89 * i2c_master_send - issue a single I2C message in master transmit mode 90 * @client: Handle to slave device 91 * @buf: Data that will be written to the slave 92 * @count: How many bytes to write, must be less than 64k since msg.len is u16 93 * 94 * Returns negative errno, or else the number of bytes written. 95 */ 96 static inline int i2c_master_send(const struct i2c_client *client, 97 const char *buf, int count) 98 { 99 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 100 }; 101 102 /** 103 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 104 * using a DMA safe buffer 105 * @client: Handle to slave device 106 * @buf: Data that will be written to the slave, must be safe to use with DMA 107 * @count: How many bytes to write, must be less than 64k since msg.len is u16 108 * 109 * Returns negative errno, or else the number of bytes written. 110 */ 111 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 112 const char *buf, int count) 113 { 114 return i2c_transfer_buffer_flags(client, (char *)buf, count, 115 I2C_M_DMA_SAFE); 116 }; 117 118 /* Transfer num messages. 119 */ 120 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 121 int num); 122 /* Unlocked flavor */ 123 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 124 int num); 125 126 /* This is the very generalized SMBus access routine. You probably do not 127 want to use this, though; one of the functions below may be much easier, 128 and probably just as fast. 129 Note that we use i2c_adapter here, because you do not need a specific 130 smbus adapter to call this function. */ 131 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 132 unsigned short flags, char read_write, u8 command, 133 int protocol, union i2c_smbus_data *data); 134 135 /* Unlocked flavor */ 136 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 137 unsigned short flags, char read_write, u8 command, 138 int protocol, union i2c_smbus_data *data); 139 140 /* Now follow the 'nice' access routines. These also document the calling 141 conventions of i2c_smbus_xfer. */ 142 143 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 144 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 145 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 146 u8 command); 147 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 148 u8 command, u8 value); 149 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 150 u8 command); 151 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 152 u8 command, u16 value); 153 154 static inline s32 155 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 156 { 157 s32 value = i2c_smbus_read_word_data(client, command); 158 159 return (value < 0) ? value : swab16(value); 160 } 161 162 static inline s32 163 i2c_smbus_write_word_swapped(const struct i2c_client *client, 164 u8 command, u16 value) 165 { 166 return i2c_smbus_write_word_data(client, command, swab16(value)); 167 } 168 169 /* Returns the number of read bytes */ 170 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 171 u8 command, u8 *values); 172 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 173 u8 command, u8 length, const u8 *values); 174 /* Returns the number of read bytes */ 175 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 176 u8 command, u8 length, u8 *values); 177 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 178 u8 command, u8 length, 179 const u8 *values); 180 extern s32 181 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 182 u8 command, u8 length, u8 *values); 183 int i2c_get_device_id(const struct i2c_client *client, 184 struct i2c_device_identity *id); 185 #endif /* I2C */ 186 187 /** 188 * struct i2c_device_identity - i2c client device identification 189 * @manufacturer_id: 0 - 4095, database maintained by NXP 190 * @part_id: 0 - 511, according to manufacturer 191 * @die_revision: 0 - 7, according to manufacturer 192 */ 193 struct i2c_device_identity { 194 u16 manufacturer_id; 195 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 196 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 197 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 198 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 199 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 200 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 201 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 202 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 203 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 204 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 205 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 206 #define I2C_DEVICE_ID_FLIR 11 207 #define I2C_DEVICE_ID_O2MICRO 12 208 #define I2C_DEVICE_ID_ATMEL 13 209 #define I2C_DEVICE_ID_NONE 0xffff 210 u16 part_id; 211 u8 die_revision; 212 }; 213 214 enum i2c_alert_protocol { 215 I2C_PROTOCOL_SMBUS_ALERT, 216 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 217 }; 218 219 /** 220 * struct i2c_driver - represent an I2C device driver 221 * @class: What kind of i2c device we instantiate (for detect) 222 * @probe: Callback for device binding - soon to be deprecated 223 * @probe_new: New callback for device binding 224 * @remove: Callback for device unbinding 225 * @shutdown: Callback for device shutdown 226 * @alert: Alert callback, for example for the SMBus alert protocol 227 * @command: Callback for bus-wide signaling (optional) 228 * @driver: Device driver model driver 229 * @id_table: List of I2C devices supported by this driver 230 * @detect: Callback for device detection 231 * @address_list: The I2C addresses to probe (for detect) 232 * @clients: List of detected clients we created (for i2c-core use only) 233 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 234 * 235 * The driver.owner field should be set to the module owner of this driver. 236 * The driver.name field should be set to the name of this driver. 237 * 238 * For automatic device detection, both @detect and @address_list must 239 * be defined. @class should also be set, otherwise only devices forced 240 * with module parameters will be created. The detect function must 241 * fill at least the name field of the i2c_board_info structure it is 242 * handed upon successful detection, and possibly also the flags field. 243 * 244 * If @detect is missing, the driver will still work fine for enumerated 245 * devices. Detected devices simply won't be supported. This is expected 246 * for the many I2C/SMBus devices which can't be detected reliably, and 247 * the ones which can always be enumerated in practice. 248 * 249 * The i2c_client structure which is handed to the @detect callback is 250 * not a real i2c_client. It is initialized just enough so that you can 251 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 252 * else with it. In particular, calling dev_dbg and friends on it is 253 * not allowed. 254 */ 255 struct i2c_driver { 256 unsigned int class; 257 258 /* Standard driver model interfaces */ 259 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 260 int (*remove)(struct i2c_client *); 261 262 /* New driver model interface to aid the seamless removal of the 263 * current probe()'s, more commonly unused than used second parameter. 264 */ 265 int (*probe_new)(struct i2c_client *); 266 267 /* driver model interfaces that don't relate to enumeration */ 268 void (*shutdown)(struct i2c_client *); 269 270 /* Alert callback, for example for the SMBus alert protocol. 271 * The format and meaning of the data value depends on the protocol. 272 * For the SMBus alert protocol, there is a single bit of data passed 273 * as the alert response's low bit ("event flag"). 274 * For the SMBus Host Notify protocol, the data corresponds to the 275 * 16-bit payload data reported by the slave device acting as master. 276 */ 277 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, 278 unsigned int data); 279 280 /* a ioctl like command that can be used to perform specific functions 281 * with the device. 282 */ 283 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 284 285 struct device_driver driver; 286 const struct i2c_device_id *id_table; 287 288 /* Device detection callback for automatic device creation */ 289 int (*detect)(struct i2c_client *, struct i2c_board_info *); 290 const unsigned short *address_list; 291 struct list_head clients; 292 293 bool disable_i2c_core_irq_mapping; 294 }; 295 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 296 297 /** 298 * struct i2c_client - represent an I2C slave device 299 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 300 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 301 * @addr: Address used on the I2C bus connected to the parent adapter. 302 * @name: Indicates the type of the device, usually a chip name that's 303 * generic enough to hide second-sourcing and compatible revisions. 304 * @adapter: manages the bus segment hosting this I2C device 305 * @dev: Driver model device node for the slave. 306 * @irq: indicates the IRQ generated by this device (if any) 307 * @detected: member of an i2c_driver.clients list or i2c-core's 308 * userspace_devices list 309 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 310 * calls it to pass on slave events to the slave driver. 311 * 312 * An i2c_client identifies a single device (i.e. chip) connected to an 313 * i2c bus. The behaviour exposed to Linux is defined by the driver 314 * managing the device. 315 */ 316 struct i2c_client { 317 unsigned short flags; /* div., see below */ 318 unsigned short addr; /* chip address - NOTE: 7bit */ 319 /* addresses are stored in the */ 320 /* _LOWER_ 7 bits */ 321 char name[I2C_NAME_SIZE]; 322 struct i2c_adapter *adapter; /* the adapter we sit on */ 323 struct device dev; /* the device structure */ 324 int init_irq; /* irq set at initialization */ 325 int irq; /* irq issued by device */ 326 struct list_head detected; 327 #if IS_ENABLED(CONFIG_I2C_SLAVE) 328 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 329 #endif 330 }; 331 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 332 333 extern struct i2c_client *i2c_verify_client(struct device *dev); 334 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 335 extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 336 const struct i2c_client *client); 337 338 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 339 { 340 struct device * const dev = container_of(kobj, struct device, kobj); 341 return to_i2c_client(dev); 342 } 343 344 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 345 { 346 return dev_get_drvdata(&dev->dev); 347 } 348 349 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 350 { 351 dev_set_drvdata(&dev->dev, data); 352 } 353 354 /* I2C slave support */ 355 356 #if IS_ENABLED(CONFIG_I2C_SLAVE) 357 enum i2c_slave_event { 358 I2C_SLAVE_READ_REQUESTED, 359 I2C_SLAVE_WRITE_REQUESTED, 360 I2C_SLAVE_READ_PROCESSED, 361 I2C_SLAVE_WRITE_RECEIVED, 362 I2C_SLAVE_STOP, 363 }; 364 365 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 366 extern int i2c_slave_unregister(struct i2c_client *client); 367 extern bool i2c_detect_slave_mode(struct device *dev); 368 369 static inline int i2c_slave_event(struct i2c_client *client, 370 enum i2c_slave_event event, u8 *val) 371 { 372 return client->slave_cb(client, event, val); 373 } 374 #else 375 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 376 #endif 377 378 /** 379 * struct i2c_board_info - template for device creation 380 * @type: chip type, to initialize i2c_client.name 381 * @flags: to initialize i2c_client.flags 382 * @addr: stored in i2c_client.addr 383 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 384 * @platform_data: stored in i2c_client.dev.platform_data 385 * @of_node: pointer to OpenFirmware device node 386 * @fwnode: device node supplied by the platform firmware 387 * @properties: additional device properties for the device 388 * @resources: resources associated with the device 389 * @num_resources: number of resources in the @resources array 390 * @irq: stored in i2c_client.irq 391 * 392 * I2C doesn't actually support hardware probing, although controllers and 393 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 394 * a device at a given address. Drivers commonly need more information than 395 * that, such as chip type, configuration, associated IRQ, and so on. 396 * 397 * i2c_board_info is used to build tables of information listing I2C devices 398 * that are present. This information is used to grow the driver model tree. 399 * For mainboards this is done statically using i2c_register_board_info(); 400 * bus numbers identify adapters that aren't yet available. For add-on boards, 401 * i2c_new_device() does this dynamically with the adapter already known. 402 */ 403 struct i2c_board_info { 404 char type[I2C_NAME_SIZE]; 405 unsigned short flags; 406 unsigned short addr; 407 const char *dev_name; 408 void *platform_data; 409 struct device_node *of_node; 410 struct fwnode_handle *fwnode; 411 const struct property_entry *properties; 412 const struct resource *resources; 413 unsigned int num_resources; 414 int irq; 415 }; 416 417 /** 418 * I2C_BOARD_INFO - macro used to list an i2c device and its address 419 * @dev_type: identifies the device type 420 * @dev_addr: the device's address on the bus. 421 * 422 * This macro initializes essential fields of a struct i2c_board_info, 423 * declaring what has been provided on a particular board. Optional 424 * fields (such as associated irq, or device-specific platform_data) 425 * are provided using conventional syntax. 426 */ 427 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 428 .type = dev_type, .addr = (dev_addr) 429 430 431 #if IS_ENABLED(CONFIG_I2C) 432 /* Add-on boards should register/unregister their devices; e.g. a board 433 * with integrated I2C, a config eeprom, sensors, and a codec that's 434 * used in conjunction with the primary hardware. 435 */ 436 extern struct i2c_client * 437 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 438 439 /* If you don't know the exact address of an I2C device, use this variant 440 * instead, which can probe for device presence in a list of possible 441 * addresses. The "probe" callback function is optional. If it is provided, 442 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 443 * a default probing method is used. 444 */ 445 extern struct i2c_client * 446 i2c_new_probed_device(struct i2c_adapter *adap, 447 struct i2c_board_info *info, 448 unsigned short const *addr_list, 449 int (*probe)(struct i2c_adapter *, unsigned short addr)); 450 451 /* Common custom probe functions */ 452 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 453 454 /* For devices that use several addresses, use i2c_new_dummy() to make 455 * client handles for the extra addresses. 456 */ 457 extern struct i2c_client * 458 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 459 460 extern struct i2c_client * 461 devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address); 462 463 extern struct i2c_client * 464 i2c_new_secondary_device(struct i2c_client *client, 465 const char *name, 466 u16 default_addr); 467 468 extern void i2c_unregister_device(struct i2c_client *); 469 #endif /* I2C */ 470 471 /* Mainboard arch_initcall() code should register all its I2C devices. 472 * This is done at arch_initcall time, before declaring any i2c adapters. 473 * Modules for add-on boards must use other calls. 474 */ 475 #ifdef CONFIG_I2C_BOARDINFO 476 extern int 477 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 478 unsigned n); 479 #else 480 static inline int 481 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 482 unsigned n) 483 { 484 return 0; 485 } 486 #endif /* I2C_BOARDINFO */ 487 488 /** 489 * struct i2c_algorithm - represent I2C transfer method 490 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 491 * defined by the msgs array, with num messages available to transfer via 492 * the adapter specified by adap. 493 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context 494 * so e.g. PMICs can be accessed very late before shutdown. Optional. 495 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 496 * is not present, then the bus layer will try and convert the SMBus calls 497 * into I2C transfers instead. 498 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context 499 * so e.g. PMICs can be accessed very late before shutdown. Optional. 500 * @functionality: Return the flags that this algorithm/adapter pair supports 501 * from the I2C_FUNC_* flags. 502 * @reg_slave: Register given client to I2C slave mode of this adapter 503 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 504 * 505 * The following structs are for those who like to implement new bus drivers: 506 * i2c_algorithm is the interface to a class of hardware solutions which can 507 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 508 * to name two of the most common. 509 * 510 * The return codes from the @master_xfer{_atomic} fields should indicate the 511 * type of error code that occurred during the transfer, as documented in the 512 * Kernel Documentation file Documentation/i2c/fault-codes. 513 */ 514 struct i2c_algorithm { 515 /* 516 * If an adapter algorithm can't do I2C-level access, set master_xfer 517 * to NULL. If an adapter algorithm can do SMBus access, set 518 * smbus_xfer. If set to NULL, the SMBus protocol is simulated 519 * using common I2C messages. 520 * 521 * master_xfer should return the number of messages successfully 522 * processed, or a negative value on error 523 */ 524 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 525 int num); 526 int (*master_xfer_atomic)(struct i2c_adapter *adap, 527 struct i2c_msg *msgs, int num); 528 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, 529 unsigned short flags, char read_write, 530 u8 command, int size, union i2c_smbus_data *data); 531 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, 532 unsigned short flags, char read_write, 533 u8 command, int size, union i2c_smbus_data *data); 534 535 /* To determine what the adapter supports */ 536 u32 (*functionality)(struct i2c_adapter *adap); 537 538 #if IS_ENABLED(CONFIG_I2C_SLAVE) 539 int (*reg_slave)(struct i2c_client *client); 540 int (*unreg_slave)(struct i2c_client *client); 541 #endif 542 }; 543 544 /** 545 * struct i2c_lock_operations - represent I2C locking operations 546 * @lock_bus: Get exclusive access to an I2C bus segment 547 * @trylock_bus: Try to get exclusive access to an I2C bus segment 548 * @unlock_bus: Release exclusive access to an I2C bus segment 549 * 550 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 551 */ 552 struct i2c_lock_operations { 553 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 554 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 555 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 556 }; 557 558 /** 559 * struct i2c_timings - I2C timing information 560 * @bus_freq_hz: the bus frequency in Hz 561 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 562 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 563 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 564 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 565 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 566 */ 567 struct i2c_timings { 568 u32 bus_freq_hz; 569 u32 scl_rise_ns; 570 u32 scl_fall_ns; 571 u32 scl_int_delay_ns; 572 u32 sda_fall_ns; 573 u32 sda_hold_ns; 574 }; 575 576 /** 577 * struct i2c_bus_recovery_info - I2C bus recovery information 578 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 579 * i2c_generic_scl_recovery(). 580 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 581 * recovery. Populated internally for generic GPIO recovery. 582 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 583 * Populated internally for generic GPIO recovery. 584 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 585 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 586 * GPIO, for generic GPIO recovery. 587 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 588 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 589 * for generic GPIO recovery. 590 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 591 * has a more complex internal logic than just reading SDA. Optional. 592 * @prepare_recovery: This will be called before starting recovery. Platform may 593 * configure padmux here for SDA/SCL line or something else they want. 594 * @unprepare_recovery: This will be called after completing recovery. Platform 595 * may configure padmux here for SDA/SCL line or something else they want. 596 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 597 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 598 */ 599 struct i2c_bus_recovery_info { 600 int (*recover_bus)(struct i2c_adapter *adap); 601 602 int (*get_scl)(struct i2c_adapter *adap); 603 void (*set_scl)(struct i2c_adapter *adap, int val); 604 int (*get_sda)(struct i2c_adapter *adap); 605 void (*set_sda)(struct i2c_adapter *adap, int val); 606 int (*get_bus_free)(struct i2c_adapter *adap); 607 608 void (*prepare_recovery)(struct i2c_adapter *adap); 609 void (*unprepare_recovery)(struct i2c_adapter *adap); 610 611 /* gpio recovery */ 612 struct gpio_desc *scl_gpiod; 613 struct gpio_desc *sda_gpiod; 614 }; 615 616 int i2c_recover_bus(struct i2c_adapter *adap); 617 618 /* Generic recovery routines */ 619 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 620 621 /** 622 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 623 * @flags: see I2C_AQ_* for possible flags and read below 624 * @max_num_msgs: maximum number of messages per transfer 625 * @max_write_len: maximum length of a write message 626 * @max_read_len: maximum length of a read message 627 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 628 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 629 * 630 * Note about combined messages: Some I2C controllers can only send one message 631 * per transfer, plus something called combined message or write-then-read. 632 * This is (usually) a small write message followed by a read message and 633 * barely enough to access register based devices like EEPROMs. There is a flag 634 * to support this mode. It implies max_num_msg = 2 and does the length checks 635 * with max_comb_*_len because combined message mode usually has its own 636 * limitations. Because of HW implementations, some controllers can actually do 637 * write-then-anything or other variants. To support that, write-then-read has 638 * been broken out into smaller bits like write-first and read-second which can 639 * be combined as needed. 640 */ 641 642 struct i2c_adapter_quirks { 643 u64 flags; 644 int max_num_msgs; 645 u16 max_write_len; 646 u16 max_read_len; 647 u16 max_comb_1st_msg_len; 648 u16 max_comb_2nd_msg_len; 649 }; 650 651 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 652 #define I2C_AQ_COMB BIT(0) 653 /* first combined message must be write */ 654 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 655 /* second combined message must be read */ 656 #define I2C_AQ_COMB_READ_SECOND BIT(2) 657 /* both combined messages must have the same target address */ 658 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 659 /* convenience macro for typical write-then read case */ 660 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 661 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 662 /* clock stretching is not supported */ 663 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 664 /* message cannot have length of 0 */ 665 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 666 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 667 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 668 669 /* 670 * i2c_adapter is the structure used to identify a physical i2c bus along 671 * with the access algorithms necessary to access it. 672 */ 673 struct i2c_adapter { 674 struct module *owner; 675 unsigned int class; /* classes to allow probing for */ 676 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 677 void *algo_data; 678 679 /* data fields that are valid for all devices */ 680 const struct i2c_lock_operations *lock_ops; 681 struct rt_mutex bus_lock; 682 struct rt_mutex mux_lock; 683 684 int timeout; /* in jiffies */ 685 int retries; 686 struct device dev; /* the adapter device */ 687 unsigned long locked_flags; /* owned by the I2C core */ 688 #define I2C_ALF_IS_SUSPENDED 0 689 #define I2C_ALF_SUSPEND_REPORTED 1 690 691 int nr; 692 char name[48]; 693 struct completion dev_released; 694 695 struct mutex userspace_clients_lock; 696 struct list_head userspace_clients; 697 698 struct i2c_bus_recovery_info *bus_recovery_info; 699 const struct i2c_adapter_quirks *quirks; 700 701 struct irq_domain *host_notify_domain; 702 }; 703 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 704 705 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 706 { 707 return dev_get_drvdata(&dev->dev); 708 } 709 710 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 711 { 712 dev_set_drvdata(&dev->dev, data); 713 } 714 715 static inline struct i2c_adapter * 716 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 717 { 718 #if IS_ENABLED(CONFIG_I2C_MUX) 719 struct device *parent = adapter->dev.parent; 720 721 if (parent != NULL && parent->type == &i2c_adapter_type) 722 return to_i2c_adapter(parent); 723 else 724 #endif 725 return NULL; 726 } 727 728 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 729 730 /* Adapter locking functions, exported for shared pin cases */ 731 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 732 #define I2C_LOCK_SEGMENT BIT(1) 733 734 /** 735 * i2c_lock_bus - Get exclusive access to an I2C bus segment 736 * @adapter: Target I2C bus segment 737 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 738 * locks only this branch in the adapter tree 739 */ 740 static inline void 741 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 742 { 743 adapter->lock_ops->lock_bus(adapter, flags); 744 } 745 746 /** 747 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 748 * @adapter: Target I2C bus segment 749 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 750 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 751 * 752 * Return: true if the I2C bus segment is locked, false otherwise 753 */ 754 static inline int 755 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 756 { 757 return adapter->lock_ops->trylock_bus(adapter, flags); 758 } 759 760 /** 761 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 762 * @adapter: Target I2C bus segment 763 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 764 * unlocks only this branch in the adapter tree 765 */ 766 static inline void 767 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 768 { 769 adapter->lock_ops->unlock_bus(adapter, flags); 770 } 771 772 /** 773 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 774 * @adap: Adapter to mark as suspended 775 * 776 * When using this helper to mark an adapter as suspended, the core will reject 777 * further transfers to this adapter. The usage of this helper is optional but 778 * recommended for devices having distinct handlers for system suspend and 779 * runtime suspend. More complex devices are free to implement custom solutions 780 * to reject transfers when suspended. 781 */ 782 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 783 { 784 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 785 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 786 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 787 } 788 789 /** 790 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 791 * @adap: Adapter to mark as resumed 792 * 793 * When using this helper to mark an adapter as resumed, the core will allow 794 * further transfers to this adapter. See also further notes to 795 * @i2c_mark_adapter_suspended(). 796 */ 797 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 798 { 799 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 800 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 801 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 802 } 803 804 /*flags for the client struct: */ 805 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 806 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 807 /* Must equal I2C_M_TEN below */ 808 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 809 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 810 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 811 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 812 /* Must match I2C_M_STOP|IGNORE_NAK */ 813 814 /* i2c adapter classes (bitmask) */ 815 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 816 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 817 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 818 /* Warn users that the adapter doesn't support classes anymore */ 819 #define I2C_CLASS_DEPRECATED (1<<8) 820 821 /* Internal numbers to terminate lists */ 822 #define I2C_CLIENT_END 0xfffeU 823 824 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 825 #define I2C_ADDRS(addr, addrs...) \ 826 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 827 828 829 /* ----- functions exported by i2c.o */ 830 831 /* administration... 832 */ 833 #if IS_ENABLED(CONFIG_I2C) 834 extern int i2c_add_adapter(struct i2c_adapter *); 835 extern void i2c_del_adapter(struct i2c_adapter *); 836 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 837 838 extern int i2c_register_driver(struct module *, struct i2c_driver *); 839 extern void i2c_del_driver(struct i2c_driver *); 840 841 /* use a define to avoid include chaining to get THIS_MODULE */ 842 #define i2c_add_driver(driver) \ 843 i2c_register_driver(THIS_MODULE, driver) 844 845 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 846 extern void i2c_release_client(struct i2c_client *client); 847 848 /* call the i2c_client->command() of all attached clients with 849 * the given arguments */ 850 extern void i2c_clients_command(struct i2c_adapter *adap, 851 unsigned int cmd, void *arg); 852 853 extern struct i2c_adapter *i2c_get_adapter(int nr); 854 extern void i2c_put_adapter(struct i2c_adapter *adap); 855 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 856 857 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 858 859 /* Return the functionality mask */ 860 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 861 { 862 return adap->algo->functionality(adap); 863 } 864 865 /* Return 1 if adapter supports everything we need, 0 if not. */ 866 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 867 { 868 return (func & i2c_get_functionality(adap)) == func; 869 } 870 871 /** 872 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 873 * @adap: i2c adapter 874 * @quirks: quirk flags 875 * 876 * Return: true if the adapter has all the specified quirk flags, false if not 877 */ 878 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 879 { 880 if (!adap->quirks) 881 return false; 882 return (adap->quirks->flags & quirks) == quirks; 883 } 884 885 /* Return the adapter number for a specific adapter */ 886 static inline int i2c_adapter_id(struct i2c_adapter *adap) 887 { 888 return adap->nr; 889 } 890 891 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 892 { 893 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 894 } 895 896 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 897 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 898 899 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 900 /** 901 * module_i2c_driver() - Helper macro for registering a modular I2C driver 902 * @__i2c_driver: i2c_driver struct 903 * 904 * Helper macro for I2C drivers which do not do anything special in module 905 * init/exit. This eliminates a lot of boilerplate. Each module may only 906 * use this macro once, and calling it replaces module_init() and module_exit() 907 */ 908 #define module_i2c_driver(__i2c_driver) \ 909 module_driver(__i2c_driver, i2c_add_driver, \ 910 i2c_del_driver) 911 912 /** 913 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 914 * @__i2c_driver: i2c_driver struct 915 * 916 * Helper macro for I2C drivers which do not do anything special in their 917 * init. This eliminates a lot of boilerplate. Each driver may only 918 * use this macro once, and calling it replaces device_initcall(). 919 */ 920 #define builtin_i2c_driver(__i2c_driver) \ 921 builtin_driver(__i2c_driver, i2c_add_driver) 922 923 #endif /* I2C */ 924 925 #if IS_ENABLED(CONFIG_OF) 926 /* must call put_device() when done with returned i2c_client device */ 927 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 928 929 /* must call put_device() when done with returned i2c_adapter device */ 930 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 931 932 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 933 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 934 935 extern const struct of_device_id 936 *i2c_of_match_device(const struct of_device_id *matches, 937 struct i2c_client *client); 938 939 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 940 struct i2c_board_info *info); 941 942 #else 943 944 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 945 { 946 return NULL; 947 } 948 949 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 950 { 951 return NULL; 952 } 953 954 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 955 { 956 return NULL; 957 } 958 959 static inline const struct of_device_id 960 *i2c_of_match_device(const struct of_device_id *matches, 961 struct i2c_client *client) 962 { 963 return NULL; 964 } 965 966 static inline int of_i2c_get_board_info(struct device *dev, 967 struct device_node *node, 968 struct i2c_board_info *info) 969 { 970 return -ENOTSUPP; 971 } 972 973 #endif /* CONFIG_OF */ 974 975 struct acpi_resource; 976 struct acpi_resource_i2c_serialbus; 977 978 #if IS_ENABLED(CONFIG_ACPI) 979 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 980 struct acpi_resource_i2c_serialbus **i2c); 981 u32 i2c_acpi_find_bus_speed(struct device *dev); 982 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 983 struct i2c_board_info *info); 984 #else 985 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 986 struct acpi_resource_i2c_serialbus **i2c) 987 { 988 return false; 989 } 990 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 991 { 992 return 0; 993 } 994 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 995 int index, struct i2c_board_info *info) 996 { 997 return NULL; 998 } 999 #endif /* CONFIG_ACPI */ 1000 1001 #endif /* _LINUX_I2C_H */ 1002