1 /* ------------------------------------------------------------------------- */ 2 /* */ 3 /* i2c.h - definitions for the i2c-bus interface */ 4 /* */ 5 /* ------------------------------------------------------------------------- */ 6 /* Copyright (C) 1995-2000 Simon G. Vogl 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 21 MA 02110-1301 USA. */ 22 /* ------------------------------------------------------------------------- */ 23 24 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and 25 Frodo Looijaard <frodol@dds.nl> */ 26 #ifndef _LINUX_I2C_H 27 #define _LINUX_I2C_H 28 29 #include <linux/mod_devicetable.h> 30 #include <linux/device.h> /* for struct device */ 31 #include <linux/sched.h> /* for completion */ 32 #include <linux/mutex.h> 33 #include <linux/rtmutex.h> 34 #include <linux/irqdomain.h> /* for Host Notify IRQ */ 35 #include <linux/of.h> /* for struct device_node */ 36 #include <linux/swab.h> /* for swab16 */ 37 #include <uapi/linux/i2c.h> 38 39 extern struct bus_type i2c_bus_type; 40 extern struct device_type i2c_adapter_type; 41 extern struct device_type i2c_client_type; 42 43 /* --- General options ------------------------------------------------ */ 44 45 struct i2c_msg; 46 struct i2c_algorithm; 47 struct i2c_adapter; 48 struct i2c_client; 49 struct i2c_driver; 50 struct i2c_device_identity; 51 union i2c_smbus_data; 52 struct i2c_board_info; 53 enum i2c_slave_event; 54 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 55 56 struct module; 57 struct property_entry; 58 59 #if IS_ENABLED(CONFIG_I2C) 60 /* 61 * The master routines are the ones normally used to transmit data to devices 62 * on a bus (or read from them). Apart from two basic transfer functions to 63 * transmit one message at a time, a more complex version can be used to 64 * transmit an arbitrary number of messages without interruption. 65 * @count must be be less than 64k since msg.len is u16. 66 */ 67 extern int i2c_transfer_buffer_flags(const struct i2c_client *client, 68 char *buf, int count, u16 flags); 69 70 /** 71 * i2c_master_recv - issue a single I2C message in master receive mode 72 * @client: Handle to slave device 73 * @buf: Where to store data read from slave 74 * @count: How many bytes to read, must be less than 64k since msg.len is u16 75 * 76 * Returns negative errno, or else the number of bytes read. 77 */ 78 static inline int i2c_master_recv(const struct i2c_client *client, 79 char *buf, int count) 80 { 81 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 82 }; 83 84 /** 85 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 86 * using a DMA safe buffer 87 * @client: Handle to slave device 88 * @buf: Where to store data read from slave, must be safe to use with DMA 89 * @count: How many bytes to read, must be less than 64k since msg.len is u16 90 * 91 * Returns negative errno, or else the number of bytes read. 92 */ 93 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 94 char *buf, int count) 95 { 96 return i2c_transfer_buffer_flags(client, buf, count, 97 I2C_M_RD | I2C_M_DMA_SAFE); 98 }; 99 100 /** 101 * i2c_master_send - issue a single I2C message in master transmit mode 102 * @client: Handle to slave device 103 * @buf: Data that will be written to the slave 104 * @count: How many bytes to write, must be less than 64k since msg.len is u16 105 * 106 * Returns negative errno, or else the number of bytes written. 107 */ 108 static inline int i2c_master_send(const struct i2c_client *client, 109 const char *buf, int count) 110 { 111 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 112 }; 113 114 /** 115 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 116 * using a DMA safe buffer 117 * @client: Handle to slave device 118 * @buf: Data that will be written to the slave, must be safe to use with DMA 119 * @count: How many bytes to write, must be less than 64k since msg.len is u16 120 * 121 * Returns negative errno, or else the number of bytes written. 122 */ 123 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 124 const char *buf, int count) 125 { 126 return i2c_transfer_buffer_flags(client, (char *)buf, count, 127 I2C_M_DMA_SAFE); 128 }; 129 130 /* Transfer num messages. 131 */ 132 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 133 int num); 134 /* Unlocked flavor */ 135 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 136 int num); 137 138 /* This is the very generalized SMBus access routine. You probably do not 139 want to use this, though; one of the functions below may be much easier, 140 and probably just as fast. 141 Note that we use i2c_adapter here, because you do not need a specific 142 smbus adapter to call this function. */ 143 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 144 unsigned short flags, char read_write, u8 command, 145 int size, union i2c_smbus_data *data); 146 147 /* Now follow the 'nice' access routines. These also document the calling 148 conventions of i2c_smbus_xfer. */ 149 150 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 151 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 152 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 153 u8 command); 154 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 155 u8 command, u8 value); 156 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 157 u8 command); 158 extern 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 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 178 u8 command, u8 *values); 179 extern 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 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 183 u8 command, u8 length, u8 *values); 184 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 185 u8 command, u8 length, 186 const u8 *values); 187 extern s32 188 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 189 u8 command, u8 length, 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 * struct i2c_driver - represent an I2C device driver 228 * @class: What kind of i2c device we instantiate (for detect) 229 * @attach_adapter: Callback for bus addition (deprecated) 230 * @probe: Callback for device binding - soon to be deprecated 231 * @probe_new: New callback for device binding 232 * @remove: Callback for device unbinding 233 * @shutdown: Callback for device shutdown 234 * @alert: Alert callback, for example for the SMBus alert protocol 235 * @command: Callback for bus-wide signaling (optional) 236 * @driver: Device driver model driver 237 * @id_table: List of I2C devices supported by this driver 238 * @detect: Callback for device detection 239 * @address_list: The I2C addresses to probe (for detect) 240 * @clients: List of detected clients we created (for i2c-core use only) 241 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 242 * 243 * The driver.owner field should be set to the module owner of this driver. 244 * The driver.name field should be set to the name of this driver. 245 * 246 * For automatic device detection, both @detect and @address_list must 247 * be defined. @class should also be set, otherwise only devices forced 248 * with module parameters will be created. The detect function must 249 * fill at least the name field of the i2c_board_info structure it is 250 * handed upon successful detection, and possibly also the flags field. 251 * 252 * If @detect is missing, the driver will still work fine for enumerated 253 * devices. Detected devices simply won't be supported. This is expected 254 * for the many I2C/SMBus devices which can't be detected reliably, and 255 * the ones which can always be enumerated in practice. 256 * 257 * The i2c_client structure which is handed to the @detect callback is 258 * not a real i2c_client. It is initialized just enough so that you can 259 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 260 * else with it. In particular, calling dev_dbg and friends on it is 261 * not allowed. 262 */ 263 struct i2c_driver { 264 unsigned int class; 265 266 /* Notifies the driver that a new bus has appeared. You should avoid 267 * using this, it will be removed in a near future. 268 */ 269 int (*attach_adapter)(struct i2c_adapter *) __deprecated; 270 271 /* Standard driver model interfaces */ 272 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 273 int (*remove)(struct i2c_client *); 274 275 /* New driver model interface to aid the seamless removal of the 276 * current probe()'s, more commonly unused than used second parameter. 277 */ 278 int (*probe_new)(struct i2c_client *); 279 280 /* driver model interfaces that don't relate to enumeration */ 281 void (*shutdown)(struct i2c_client *); 282 283 /* Alert callback, for example for the SMBus alert protocol. 284 * The format and meaning of the data value depends on the protocol. 285 * For the SMBus alert protocol, there is a single bit of data passed 286 * as the alert response's low bit ("event flag"). 287 * For the SMBus Host Notify protocol, the data corresponds to the 288 * 16-bit payload data reported by the slave device acting as master. 289 */ 290 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, 291 unsigned int data); 292 293 /* a ioctl like command that can be used to perform specific functions 294 * with the device. 295 */ 296 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 297 298 struct device_driver driver; 299 const struct i2c_device_id *id_table; 300 301 /* Device detection callback for automatic device creation */ 302 int (*detect)(struct i2c_client *, struct i2c_board_info *); 303 const unsigned short *address_list; 304 struct list_head clients; 305 306 bool disable_i2c_core_irq_mapping; 307 }; 308 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 309 310 /** 311 * struct i2c_client - represent an I2C slave device 312 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 313 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 314 * @addr: Address used on the I2C bus connected to the parent adapter. 315 * @name: Indicates the type of the device, usually a chip name that's 316 * generic enough to hide second-sourcing and compatible revisions. 317 * @adapter: manages the bus segment hosting this I2C device 318 * @dev: Driver model device node for the slave. 319 * @irq: indicates the IRQ generated by this device (if any) 320 * @detected: member of an i2c_driver.clients list or i2c-core's 321 * userspace_devices list 322 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 323 * calls it to pass on slave events to the slave driver. 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 unsigned short addr; /* chip address - NOTE: 7bit */ 332 /* addresses are stored in the */ 333 /* _LOWER_ 7 bits */ 334 char name[I2C_NAME_SIZE]; 335 struct i2c_adapter *adapter; /* the adapter we sit on */ 336 struct device dev; /* the device structure */ 337 int irq; /* irq issued by device */ 338 struct list_head detected; 339 #if IS_ENABLED(CONFIG_I2C_SLAVE) 340 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 341 #endif 342 }; 343 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 344 345 extern struct i2c_client *i2c_verify_client(struct device *dev); 346 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 347 extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 348 const struct i2c_client *client); 349 350 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 351 { 352 struct device * const dev = container_of(kobj, struct device, kobj); 353 return to_i2c_client(dev); 354 } 355 356 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 357 { 358 return dev_get_drvdata(&dev->dev); 359 } 360 361 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 362 { 363 dev_set_drvdata(&dev->dev, data); 364 } 365 366 /* I2C slave support */ 367 368 #if IS_ENABLED(CONFIG_I2C_SLAVE) 369 enum i2c_slave_event { 370 I2C_SLAVE_READ_REQUESTED, 371 I2C_SLAVE_WRITE_REQUESTED, 372 I2C_SLAVE_READ_PROCESSED, 373 I2C_SLAVE_WRITE_RECEIVED, 374 I2C_SLAVE_STOP, 375 }; 376 377 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 378 extern int i2c_slave_unregister(struct i2c_client *client); 379 extern bool i2c_detect_slave_mode(struct device *dev); 380 381 static inline int i2c_slave_event(struct i2c_client *client, 382 enum i2c_slave_event event, u8 *val) 383 { 384 return client->slave_cb(client, event, val); 385 } 386 #else 387 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 388 #endif 389 390 /** 391 * struct i2c_board_info - template for device creation 392 * @type: chip type, to initialize i2c_client.name 393 * @flags: to initialize i2c_client.flags 394 * @addr: stored in i2c_client.addr 395 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 396 * @platform_data: stored in i2c_client.dev.platform_data 397 * @of_node: pointer to OpenFirmware device node 398 * @fwnode: device node supplied by the platform firmware 399 * @properties: additional device properties for the device 400 * @resources: resources associated with the device 401 * @num_resources: number of resources in the @resources array 402 * @irq: stored in i2c_client.irq 403 * 404 * I2C doesn't actually support hardware probing, although controllers and 405 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 406 * a device at a given address. Drivers commonly need more information than 407 * that, such as chip type, configuration, associated IRQ, and so on. 408 * 409 * i2c_board_info is used to build tables of information listing I2C devices 410 * that are present. This information is used to grow the driver model tree. 411 * For mainboards this is done statically using i2c_register_board_info(); 412 * bus numbers identify adapters that aren't yet available. For add-on boards, 413 * i2c_new_device() does this dynamically with the adapter already known. 414 */ 415 struct i2c_board_info { 416 char type[I2C_NAME_SIZE]; 417 unsigned short flags; 418 unsigned short addr; 419 const char *dev_name; 420 void *platform_data; 421 struct device_node *of_node; 422 struct fwnode_handle *fwnode; 423 const struct property_entry *properties; 424 const struct resource *resources; 425 unsigned int num_resources; 426 int irq; 427 }; 428 429 /** 430 * I2C_BOARD_INFO - macro used to list an i2c device and its address 431 * @dev_type: identifies the device type 432 * @dev_addr: the device's address on the bus. 433 * 434 * This macro initializes essential fields of a struct i2c_board_info, 435 * declaring what has been provided on a particular board. Optional 436 * fields (such as associated irq, or device-specific platform_data) 437 * are provided using conventional syntax. 438 */ 439 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 440 .type = dev_type, .addr = (dev_addr) 441 442 443 #if IS_ENABLED(CONFIG_I2C) 444 /* Add-on boards should register/unregister their devices; e.g. a board 445 * with integrated I2C, a config eeprom, sensors, and a codec that's 446 * used in conjunction with the primary hardware. 447 */ 448 extern struct i2c_client * 449 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 450 451 /* If you don't know the exact address of an I2C device, use this variant 452 * instead, which can probe for device presence in a list of possible 453 * addresses. The "probe" callback function is optional. If it is provided, 454 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 455 * a default probing method is used. 456 */ 457 extern struct i2c_client * 458 i2c_new_probed_device(struct i2c_adapter *adap, 459 struct i2c_board_info *info, 460 unsigned short const *addr_list, 461 int (*probe)(struct i2c_adapter *, unsigned short addr)); 462 463 /* Common custom probe functions */ 464 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 465 466 /* For devices that use several addresses, use i2c_new_dummy() to make 467 * client handles for the extra addresses. 468 */ 469 extern struct i2c_client * 470 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 471 472 extern struct i2c_client * 473 i2c_new_secondary_device(struct i2c_client *client, 474 const char *name, 475 u16 default_addr); 476 477 extern void i2c_unregister_device(struct i2c_client *); 478 #endif /* I2C */ 479 480 /* Mainboard arch_initcall() code should register all its I2C devices. 481 * This is done at arch_initcall time, before declaring any i2c adapters. 482 * Modules for add-on boards must use other calls. 483 */ 484 #ifdef CONFIG_I2C_BOARDINFO 485 extern int 486 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 487 unsigned n); 488 #else 489 static inline int 490 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 491 unsigned n) 492 { 493 return 0; 494 } 495 #endif /* I2C_BOARDINFO */ 496 497 /** 498 * struct i2c_algorithm - represent I2C transfer method 499 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 500 * defined by the msgs array, with num messages available to transfer via 501 * the adapter specified by adap. 502 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 503 * is not present, then the bus layer will try and convert the SMBus calls 504 * into I2C transfers instead. 505 * @functionality: Return the flags that this algorithm/adapter pair supports 506 * from the I2C_FUNC_* flags. 507 * @reg_slave: Register given client to I2C slave mode of this adapter 508 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 509 * 510 * The following structs are for those who like to implement new bus drivers: 511 * i2c_algorithm is the interface to a class of hardware solutions which can 512 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 513 * to name two of the most common. 514 * 515 * The return codes from the @master_xfer field should indicate the type of 516 * error code that occurred during the transfer, as documented in the kernel 517 * Documentation file Documentation/i2c/fault-codes. 518 */ 519 struct i2c_algorithm { 520 /* If an adapter algorithm can't do I2C-level access, set master_xfer 521 to NULL. If an adapter algorithm can do SMBus access, set 522 smbus_xfer. If set to NULL, the SMBus protocol is simulated 523 using common I2C messages */ 524 /* master_xfer should return the number of messages successfully 525 processed, or a negative value on error */ 526 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 527 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); 531 532 /* To determine what the adapter supports */ 533 u32 (*functionality) (struct i2c_adapter *); 534 535 #if IS_ENABLED(CONFIG_I2C_SLAVE) 536 int (*reg_slave)(struct i2c_client *client); 537 int (*unreg_slave)(struct i2c_client *client); 538 #endif 539 }; 540 541 /** 542 * struct i2c_lock_operations - represent I2C locking operations 543 * @lock_bus: Get exclusive access to an I2C bus segment 544 * @trylock_bus: Try to get exclusive access to an I2C bus segment 545 * @unlock_bus: Release exclusive access to an I2C bus segment 546 * 547 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 548 */ 549 struct i2c_lock_operations { 550 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 551 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 552 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 553 }; 554 555 /** 556 * struct i2c_timings - I2C timing information 557 * @bus_freq_hz: the bus frequency in Hz 558 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 559 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 560 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 561 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 562 */ 563 struct i2c_timings { 564 u32 bus_freq_hz; 565 u32 scl_rise_ns; 566 u32 scl_fall_ns; 567 u32 scl_int_delay_ns; 568 u32 sda_fall_ns; 569 }; 570 571 /** 572 * struct i2c_bus_recovery_info - I2C bus recovery information 573 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 574 * i2c_generic_scl_recovery(). 575 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 576 * recovery. Populated internally for generic GPIO recovery. 577 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 578 * Populated internally for generic GPIO recovery. 579 * @get_sda: This gets current value of SDA line. Optional for generic SCL 580 * recovery. Populated internally, if sda_gpio is a valid GPIO, for generic 581 * GPIO recovery. 582 * @set_sda: This sets/clears the SDA line. Optional for generic SCL recovery. 583 * Populated internally, if sda_gpio is a valid GPIO, for generic GPIO 584 * recovery. 585 * @prepare_recovery: This will be called before starting recovery. Platform may 586 * configure padmux here for SDA/SCL line or something else they want. 587 * @unprepare_recovery: This will be called after completing recovery. Platform 588 * may configure padmux here for SDA/SCL line or something else they want. 589 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 590 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 591 */ 592 struct i2c_bus_recovery_info { 593 int (*recover_bus)(struct i2c_adapter *adap); 594 595 int (*get_scl)(struct i2c_adapter *adap); 596 void (*set_scl)(struct i2c_adapter *adap, int val); 597 int (*get_sda)(struct i2c_adapter *adap); 598 void (*set_sda)(struct i2c_adapter *adap, int val); 599 600 void (*prepare_recovery)(struct i2c_adapter *adap); 601 void (*unprepare_recovery)(struct i2c_adapter *adap); 602 603 /* gpio recovery */ 604 struct gpio_desc *scl_gpiod; 605 struct gpio_desc *sda_gpiod; 606 }; 607 608 int i2c_recover_bus(struct i2c_adapter *adap); 609 610 /* Generic recovery routines */ 611 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 612 613 /** 614 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 615 * @flags: see I2C_AQ_* for possible flags and read below 616 * @max_num_msgs: maximum number of messages per transfer 617 * @max_write_len: maximum length of a write message 618 * @max_read_len: maximum length of a read message 619 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 620 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 621 * 622 * Note about combined messages: Some I2C controllers can only send one message 623 * per transfer, plus something called combined message or write-then-read. 624 * This is (usually) a small write message followed by a read message and 625 * barely enough to access register based devices like EEPROMs. There is a flag 626 * to support this mode. It implies max_num_msg = 2 and does the length checks 627 * with max_comb_*_len because combined message mode usually has its own 628 * limitations. Because of HW implementations, some controllers can actually do 629 * write-then-anything or other variants. To support that, write-then-read has 630 * been broken out into smaller bits like write-first and read-second which can 631 * be combined as needed. 632 */ 633 634 struct i2c_adapter_quirks { 635 u64 flags; 636 int max_num_msgs; 637 u16 max_write_len; 638 u16 max_read_len; 639 u16 max_comb_1st_msg_len; 640 u16 max_comb_2nd_msg_len; 641 }; 642 643 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 644 #define I2C_AQ_COMB BIT(0) 645 /* first combined message must be write */ 646 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 647 /* second combined message must be read */ 648 #define I2C_AQ_COMB_READ_SECOND BIT(2) 649 /* both combined messages must have the same target address */ 650 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 651 /* convenience macro for typical write-then read case */ 652 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 653 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 654 /* clock stretching is not supported */ 655 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 656 657 /* 658 * i2c_adapter is the structure used to identify a physical i2c bus along 659 * with the access algorithms necessary to access it. 660 */ 661 struct i2c_adapter { 662 struct module *owner; 663 unsigned int class; /* classes to allow probing for */ 664 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 665 void *algo_data; 666 667 /* data fields that are valid for all devices */ 668 const struct i2c_lock_operations *lock_ops; 669 struct rt_mutex bus_lock; 670 struct rt_mutex mux_lock; 671 672 int timeout; /* in jiffies */ 673 int retries; 674 struct device dev; /* the adapter device */ 675 676 int nr; 677 char name[48]; 678 struct completion dev_released; 679 680 struct mutex userspace_clients_lock; 681 struct list_head userspace_clients; 682 683 struct i2c_bus_recovery_info *bus_recovery_info; 684 const struct i2c_adapter_quirks *quirks; 685 686 struct irq_domain *host_notify_domain; 687 }; 688 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 689 690 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 691 { 692 return dev_get_drvdata(&dev->dev); 693 } 694 695 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 696 { 697 dev_set_drvdata(&dev->dev, data); 698 } 699 700 static inline struct i2c_adapter * 701 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 702 { 703 #if IS_ENABLED(CONFIG_I2C_MUX) 704 struct device *parent = adapter->dev.parent; 705 706 if (parent != NULL && parent->type == &i2c_adapter_type) 707 return to_i2c_adapter(parent); 708 else 709 #endif 710 return NULL; 711 } 712 713 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 714 715 /* Adapter locking functions, exported for shared pin cases */ 716 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 717 #define I2C_LOCK_SEGMENT BIT(1) 718 719 /** 720 * i2c_lock_bus - Get exclusive access to an I2C bus segment 721 * @adapter: Target I2C bus segment 722 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 723 * locks only this branch in the adapter tree 724 */ 725 static inline void 726 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 727 { 728 adapter->lock_ops->lock_bus(adapter, flags); 729 } 730 731 /** 732 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 733 * @adapter: Target I2C bus segment 734 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 735 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 736 * 737 * Return: true if the I2C bus segment is locked, false otherwise 738 */ 739 static inline int 740 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 741 { 742 return adapter->lock_ops->trylock_bus(adapter, flags); 743 } 744 745 /** 746 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 747 * @adapter: Target I2C bus segment 748 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 749 * unlocks only this branch in the adapter tree 750 */ 751 static inline void 752 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 753 { 754 adapter->lock_ops->unlock_bus(adapter, flags); 755 } 756 757 static inline void 758 i2c_lock_adapter(struct i2c_adapter *adapter) 759 { 760 i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 761 } 762 763 static inline void 764 i2c_unlock_adapter(struct i2c_adapter *adapter) 765 { 766 i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 767 } 768 769 /*flags for the client struct: */ 770 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 771 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 772 /* Must equal I2C_M_TEN below */ 773 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 774 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 775 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 776 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 777 /* Must match I2C_M_STOP|IGNORE_NAK */ 778 779 /* i2c adapter classes (bitmask) */ 780 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 781 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 782 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 783 /* Warn users that the adapter doesn't support classes anymore */ 784 #define I2C_CLASS_DEPRECATED (1<<8) 785 786 /* Internal numbers to terminate lists */ 787 #define I2C_CLIENT_END 0xfffeU 788 789 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 790 #define I2C_ADDRS(addr, addrs...) \ 791 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 792 793 794 /* ----- functions exported by i2c.o */ 795 796 /* administration... 797 */ 798 #if IS_ENABLED(CONFIG_I2C) 799 extern int i2c_add_adapter(struct i2c_adapter *); 800 extern void i2c_del_adapter(struct i2c_adapter *); 801 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 802 803 extern int i2c_register_driver(struct module *, struct i2c_driver *); 804 extern void i2c_del_driver(struct i2c_driver *); 805 806 /* use a define to avoid include chaining to get THIS_MODULE */ 807 #define i2c_add_driver(driver) \ 808 i2c_register_driver(THIS_MODULE, driver) 809 810 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 811 extern void i2c_release_client(struct i2c_client *client); 812 813 /* call the i2c_client->command() of all attached clients with 814 * the given arguments */ 815 extern void i2c_clients_command(struct i2c_adapter *adap, 816 unsigned int cmd, void *arg); 817 818 extern struct i2c_adapter *i2c_get_adapter(int nr); 819 extern void i2c_put_adapter(struct i2c_adapter *adap); 820 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 821 822 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 823 824 /* Return the functionality mask */ 825 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 826 { 827 return adap->algo->functionality(adap); 828 } 829 830 /* Return 1 if adapter supports everything we need, 0 if not. */ 831 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 832 { 833 return (func & i2c_get_functionality(adap)) == func; 834 } 835 836 /** 837 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 838 * @adap: i2c adapter 839 * @quirks: quirk flags 840 * 841 * Return: true if the adapter has all the specified quirk flags, false if not 842 */ 843 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 844 { 845 if (!adap->quirks) 846 return false; 847 return (adap->quirks->flags & quirks) == quirks; 848 } 849 850 /* Return the adapter number for a specific adapter */ 851 static inline int i2c_adapter_id(struct i2c_adapter *adap) 852 { 853 return adap->nr; 854 } 855 856 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 857 { 858 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 859 } 860 861 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 862 void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf); 863 864 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 865 /** 866 * module_i2c_driver() - Helper macro for registering a modular I2C driver 867 * @__i2c_driver: i2c_driver struct 868 * 869 * Helper macro for I2C drivers which do not do anything special in module 870 * init/exit. This eliminates a lot of boilerplate. Each module may only 871 * use this macro once, and calling it replaces module_init() and module_exit() 872 */ 873 #define module_i2c_driver(__i2c_driver) \ 874 module_driver(__i2c_driver, i2c_add_driver, \ 875 i2c_del_driver) 876 877 /** 878 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 879 * @__i2c_driver: i2c_driver struct 880 * 881 * Helper macro for I2C drivers which do not do anything special in their 882 * init. This eliminates a lot of boilerplate. Each driver may only 883 * use this macro once, and calling it replaces device_initcall(). 884 */ 885 #define builtin_i2c_driver(__i2c_driver) \ 886 builtin_driver(__i2c_driver, i2c_add_driver) 887 888 #endif /* I2C */ 889 890 #if IS_ENABLED(CONFIG_OF) 891 /* must call put_device() when done with returned i2c_client device */ 892 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 893 894 /* must call put_device() when done with returned i2c_adapter device */ 895 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 896 897 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 898 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 899 900 extern const struct of_device_id 901 *i2c_of_match_device(const struct of_device_id *matches, 902 struct i2c_client *client); 903 904 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 905 struct i2c_board_info *info); 906 907 #else 908 909 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 910 { 911 return NULL; 912 } 913 914 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 915 { 916 return NULL; 917 } 918 919 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 920 { 921 return NULL; 922 } 923 924 static inline const struct of_device_id 925 *i2c_of_match_device(const struct of_device_id *matches, 926 struct i2c_client *client) 927 { 928 return NULL; 929 } 930 931 static inline int of_i2c_get_board_info(struct device *dev, 932 struct device_node *node, 933 struct i2c_board_info *info) 934 { 935 return -ENOTSUPP; 936 } 937 938 #endif /* CONFIG_OF */ 939 940 #if IS_ENABLED(CONFIG_ACPI) 941 u32 i2c_acpi_find_bus_speed(struct device *dev); 942 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 943 struct i2c_board_info *info); 944 #else 945 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 946 { 947 return 0; 948 } 949 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 950 int index, struct i2c_board_info *info) 951 { 952 return NULL; 953 } 954 #endif /* CONFIG_ACPI */ 955 956 #endif /* _LINUX_I2C_H */ 957