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/of.h> /* for struct device_node */ 34 #include <linux/swab.h> /* for swab16 */ 35 #include <uapi/linux/i2c.h> 36 37 extern struct bus_type i2c_bus_type; 38 extern struct device_type i2c_adapter_type; 39 40 /* --- General options ------------------------------------------------ */ 41 42 struct i2c_msg; 43 struct i2c_algorithm; 44 struct i2c_adapter; 45 struct i2c_client; 46 struct i2c_driver; 47 union i2c_smbus_data; 48 struct i2c_board_info; 49 enum i2c_slave_event; 50 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 51 52 struct module; 53 54 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 55 /* 56 * The master routines are the ones normally used to transmit data to devices 57 * on a bus (or read from them). Apart from two basic transfer functions to 58 * transmit one message at a time, a more complex version can be used to 59 * transmit an arbitrary number of messages without interruption. 60 * @count must be be less than 64k since msg.len is u16. 61 */ 62 extern int i2c_master_send(const struct i2c_client *client, const char *buf, 63 int count); 64 extern int i2c_master_recv(const struct i2c_client *client, char *buf, 65 int count); 66 67 /* Transfer num messages. 68 */ 69 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 70 int num); 71 /* Unlocked flavor */ 72 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 73 int num); 74 75 /* This is the very generalized SMBus access routine. You probably do not 76 want to use this, though; one of the functions below may be much easier, 77 and probably just as fast. 78 Note that we use i2c_adapter here, because you do not need a specific 79 smbus adapter to call this function. */ 80 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 81 unsigned short flags, char read_write, u8 command, 82 int size, union i2c_smbus_data *data); 83 84 /* Now follow the 'nice' access routines. These also document the calling 85 conventions of i2c_smbus_xfer. */ 86 87 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 88 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 89 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 90 u8 command); 91 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 92 u8 command, u8 value); 93 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 94 u8 command); 95 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 96 u8 command, u16 value); 97 98 static inline s32 99 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 100 { 101 s32 value = i2c_smbus_read_word_data(client, command); 102 103 return (value < 0) ? value : swab16(value); 104 } 105 106 static inline s32 107 i2c_smbus_write_word_swapped(const struct i2c_client *client, 108 u8 command, u16 value) 109 { 110 return i2c_smbus_write_word_data(client, command, swab16(value)); 111 } 112 113 /* Returns the number of read bytes */ 114 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 115 u8 command, u8 *values); 116 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 117 u8 command, u8 length, const u8 *values); 118 /* Returns the number of read bytes */ 119 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 120 u8 command, u8 length, u8 *values); 121 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 122 u8 command, u8 length, 123 const u8 *values); 124 extern s32 125 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 126 u8 command, u8 length, u8 *values); 127 #endif /* I2C */ 128 129 enum i2c_alert_protocol { 130 I2C_PROTOCOL_SMBUS_ALERT, 131 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 132 }; 133 134 /** 135 * struct i2c_driver - represent an I2C device driver 136 * @class: What kind of i2c device we instantiate (for detect) 137 * @attach_adapter: Callback for bus addition (deprecated) 138 * @probe: Callback for device binding 139 * @remove: Callback for device unbinding 140 * @shutdown: Callback for device shutdown 141 * @alert: Alert callback, for example for the SMBus alert protocol 142 * @command: Callback for bus-wide signaling (optional) 143 * @driver: Device driver model driver 144 * @id_table: List of I2C devices supported by this driver 145 * @detect: Callback for device detection 146 * @address_list: The I2C addresses to probe (for detect) 147 * @clients: List of detected clients we created (for i2c-core use only) 148 * 149 * The driver.owner field should be set to the module owner of this driver. 150 * The driver.name field should be set to the name of this driver. 151 * 152 * For automatic device detection, both @detect and @address_list must 153 * be defined. @class should also be set, otherwise only devices forced 154 * with module parameters will be created. The detect function must 155 * fill at least the name field of the i2c_board_info structure it is 156 * handed upon successful detection, and possibly also the flags field. 157 * 158 * If @detect is missing, the driver will still work fine for enumerated 159 * devices. Detected devices simply won't be supported. This is expected 160 * for the many I2C/SMBus devices which can't be detected reliably, and 161 * the ones which can always be enumerated in practice. 162 * 163 * The i2c_client structure which is handed to the @detect callback is 164 * not a real i2c_client. It is initialized just enough so that you can 165 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 166 * else with it. In particular, calling dev_dbg and friends on it is 167 * not allowed. 168 */ 169 struct i2c_driver { 170 unsigned int class; 171 172 /* Notifies the driver that a new bus has appeared. You should avoid 173 * using this, it will be removed in a near future. 174 */ 175 int (*attach_adapter)(struct i2c_adapter *) __deprecated; 176 177 /* Standard driver model interfaces */ 178 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 179 int (*remove)(struct i2c_client *); 180 181 /* driver model interfaces that don't relate to enumeration */ 182 void (*shutdown)(struct i2c_client *); 183 184 /* Alert callback, for example for the SMBus alert protocol. 185 * The format and meaning of the data value depends on the protocol. 186 * For the SMBus alert protocol, there is a single bit of data passed 187 * as the alert response's low bit ("event flag"). 188 * For the SMBus Host Notify protocol, the data corresponds to the 189 * 16-bit payload data reported by the slave device acting as master. 190 */ 191 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, 192 unsigned int data); 193 194 /* a ioctl like command that can be used to perform specific functions 195 * with the device. 196 */ 197 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 198 199 struct device_driver driver; 200 const struct i2c_device_id *id_table; 201 202 /* Device detection callback for automatic device creation */ 203 int (*detect)(struct i2c_client *, struct i2c_board_info *); 204 const unsigned short *address_list; 205 struct list_head clients; 206 }; 207 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 208 209 /** 210 * struct i2c_client - represent an I2C slave device 211 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 212 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 213 * @addr: Address used on the I2C bus connected to the parent adapter. 214 * @name: Indicates the type of the device, usually a chip name that's 215 * generic enough to hide second-sourcing and compatible revisions. 216 * @adapter: manages the bus segment hosting this I2C device 217 * @dev: Driver model device node for the slave. 218 * @irq: indicates the IRQ generated by this device (if any) 219 * @detected: member of an i2c_driver.clients list or i2c-core's 220 * userspace_devices list 221 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 222 * calls it to pass on slave events to the slave driver. 223 * 224 * An i2c_client identifies a single device (i.e. chip) connected to an 225 * i2c bus. The behaviour exposed to Linux is defined by the driver 226 * managing the device. 227 */ 228 struct i2c_client { 229 unsigned short flags; /* div., see below */ 230 unsigned short addr; /* chip address - NOTE: 7bit */ 231 /* addresses are stored in the */ 232 /* _LOWER_ 7 bits */ 233 char name[I2C_NAME_SIZE]; 234 struct i2c_adapter *adapter; /* the adapter we sit on */ 235 struct device dev; /* the device structure */ 236 int irq; /* irq issued by device */ 237 struct list_head detected; 238 #if IS_ENABLED(CONFIG_I2C_SLAVE) 239 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 240 #endif 241 }; 242 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 243 244 extern struct i2c_client *i2c_verify_client(struct device *dev); 245 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 246 247 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 248 { 249 struct device * const dev = container_of(kobj, struct device, kobj); 250 return to_i2c_client(dev); 251 } 252 253 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 254 { 255 return dev_get_drvdata(&dev->dev); 256 } 257 258 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 259 { 260 dev_set_drvdata(&dev->dev, data); 261 } 262 263 /* I2C slave support */ 264 265 #if IS_ENABLED(CONFIG_I2C_SLAVE) 266 enum i2c_slave_event { 267 I2C_SLAVE_READ_REQUESTED, 268 I2C_SLAVE_WRITE_REQUESTED, 269 I2C_SLAVE_READ_PROCESSED, 270 I2C_SLAVE_WRITE_RECEIVED, 271 I2C_SLAVE_STOP, 272 }; 273 274 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 275 extern int i2c_slave_unregister(struct i2c_client *client); 276 277 static inline int i2c_slave_event(struct i2c_client *client, 278 enum i2c_slave_event event, u8 *val) 279 { 280 return client->slave_cb(client, event, val); 281 } 282 #endif 283 284 /** 285 * struct i2c_board_info - template for device creation 286 * @type: chip type, to initialize i2c_client.name 287 * @flags: to initialize i2c_client.flags 288 * @addr: stored in i2c_client.addr 289 * @platform_data: stored in i2c_client.dev.platform_data 290 * @archdata: copied into i2c_client.dev.archdata 291 * @of_node: pointer to OpenFirmware device node 292 * @fwnode: device node supplied by the platform firmware 293 * @irq: stored in i2c_client.irq 294 * 295 * I2C doesn't actually support hardware probing, although controllers and 296 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 297 * a device at a given address. Drivers commonly need more information than 298 * that, such as chip type, configuration, associated IRQ, and so on. 299 * 300 * i2c_board_info is used to build tables of information listing I2C devices 301 * that are present. This information is used to grow the driver model tree. 302 * For mainboards this is done statically using i2c_register_board_info(); 303 * bus numbers identify adapters that aren't yet available. For add-on boards, 304 * i2c_new_device() does this dynamically with the adapter already known. 305 */ 306 struct i2c_board_info { 307 char type[I2C_NAME_SIZE]; 308 unsigned short flags; 309 unsigned short addr; 310 void *platform_data; 311 struct dev_archdata *archdata; 312 struct device_node *of_node; 313 struct fwnode_handle *fwnode; 314 int irq; 315 }; 316 317 /** 318 * I2C_BOARD_INFO - macro used to list an i2c device and its address 319 * @dev_type: identifies the device type 320 * @dev_addr: the device's address on the bus. 321 * 322 * This macro initializes essential fields of a struct i2c_board_info, 323 * declaring what has been provided on a particular board. Optional 324 * fields (such as associated irq, or device-specific platform_data) 325 * are provided using conventional syntax. 326 */ 327 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 328 .type = dev_type, .addr = (dev_addr) 329 330 331 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 332 /* Add-on boards should register/unregister their devices; e.g. a board 333 * with integrated I2C, a config eeprom, sensors, and a codec that's 334 * used in conjunction with the primary hardware. 335 */ 336 extern struct i2c_client * 337 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 338 339 /* If you don't know the exact address of an I2C device, use this variant 340 * instead, which can probe for device presence in a list of possible 341 * addresses. The "probe" callback function is optional. If it is provided, 342 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 343 * a default probing method is used. 344 */ 345 extern struct i2c_client * 346 i2c_new_probed_device(struct i2c_adapter *adap, 347 struct i2c_board_info *info, 348 unsigned short const *addr_list, 349 int (*probe)(struct i2c_adapter *, unsigned short addr)); 350 351 /* Common custom probe functions */ 352 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 353 354 /* For devices that use several addresses, use i2c_new_dummy() to make 355 * client handles for the extra addresses. 356 */ 357 extern struct i2c_client * 358 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 359 360 extern struct i2c_client * 361 i2c_new_secondary_device(struct i2c_client *client, 362 const char *name, 363 u16 default_addr); 364 365 extern void i2c_unregister_device(struct i2c_client *); 366 #endif /* I2C */ 367 368 /* Mainboard arch_initcall() code should register all its I2C devices. 369 * This is done at arch_initcall time, before declaring any i2c adapters. 370 * Modules for add-on boards must use other calls. 371 */ 372 #ifdef CONFIG_I2C_BOARDINFO 373 extern int 374 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 375 unsigned n); 376 #else 377 static inline int 378 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 379 unsigned n) 380 { 381 return 0; 382 } 383 #endif /* I2C_BOARDINFO */ 384 385 /** 386 * struct i2c_algorithm - represent I2C transfer method 387 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 388 * defined by the msgs array, with num messages available to transfer via 389 * the adapter specified by adap. 390 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 391 * is not present, then the bus layer will try and convert the SMBus calls 392 * into I2C transfers instead. 393 * @functionality: Return the flags that this algorithm/adapter pair supports 394 * from the I2C_FUNC_* flags. 395 * @reg_slave: Register given client to I2C slave mode of this adapter 396 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 397 * 398 * The following structs are for those who like to implement new bus drivers: 399 * i2c_algorithm is the interface to a class of hardware solutions which can 400 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 401 * to name two of the most common. 402 * 403 * The return codes from the @master_xfer field should indicate the type of 404 * error code that occurred during the transfer, as documented in the kernel 405 * Documentation file Documentation/i2c/fault-codes. 406 */ 407 struct i2c_algorithm { 408 /* If an adapter algorithm can't do I2C-level access, set master_xfer 409 to NULL. If an adapter algorithm can do SMBus access, set 410 smbus_xfer. If set to NULL, the SMBus protocol is simulated 411 using common I2C messages */ 412 /* master_xfer should return the number of messages successfully 413 processed, or a negative value on error */ 414 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 415 int num); 416 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 417 unsigned short flags, char read_write, 418 u8 command, int size, union i2c_smbus_data *data); 419 420 /* To determine what the adapter supports */ 421 u32 (*functionality) (struct i2c_adapter *); 422 423 #if IS_ENABLED(CONFIG_I2C_SLAVE) 424 int (*reg_slave)(struct i2c_client *client); 425 int (*unreg_slave)(struct i2c_client *client); 426 #endif 427 }; 428 429 /** 430 * struct i2c_lock_operations - represent I2C locking operations 431 * @lock_bus: Get exclusive access to an I2C bus segment 432 * @trylock_bus: Try to get exclusive access to an I2C bus segment 433 * @unlock_bus: Release exclusive access to an I2C bus segment 434 * 435 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 436 */ 437 struct i2c_lock_operations { 438 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 439 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 440 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 441 }; 442 443 /** 444 * struct i2c_timings - I2C timing information 445 * @bus_freq_hz: the bus frequency in Hz 446 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 447 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 448 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 449 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 450 */ 451 struct i2c_timings { 452 u32 bus_freq_hz; 453 u32 scl_rise_ns; 454 u32 scl_fall_ns; 455 u32 scl_int_delay_ns; 456 u32 sda_fall_ns; 457 }; 458 459 /** 460 * struct i2c_bus_recovery_info - I2C bus recovery information 461 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 462 * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery(). 463 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 464 * recovery. Used internally for generic GPIO recovery. 465 * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used 466 * internally for generic GPIO recovery. 467 * @get_sda: This gets current value of SDA line. Optional for generic SCL 468 * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO 469 * recovery. 470 * @prepare_recovery: This will be called before starting recovery. Platform may 471 * configure padmux here for SDA/SCL line or something else they want. 472 * @unprepare_recovery: This will be called after completing recovery. Platform 473 * may configure padmux here for SDA/SCL line or something else they want. 474 * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery. 475 * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery. 476 */ 477 struct i2c_bus_recovery_info { 478 int (*recover_bus)(struct i2c_adapter *); 479 480 int (*get_scl)(struct i2c_adapter *); 481 void (*set_scl)(struct i2c_adapter *, int val); 482 int (*get_sda)(struct i2c_adapter *); 483 484 void (*prepare_recovery)(struct i2c_adapter *); 485 void (*unprepare_recovery)(struct i2c_adapter *); 486 487 /* gpio recovery */ 488 int scl_gpio; 489 int sda_gpio; 490 }; 491 492 int i2c_recover_bus(struct i2c_adapter *adap); 493 494 /* Generic recovery routines */ 495 int i2c_generic_gpio_recovery(struct i2c_adapter *adap); 496 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 497 498 /** 499 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 500 * @flags: see I2C_AQ_* for possible flags and read below 501 * @max_num_msgs: maximum number of messages per transfer 502 * @max_write_len: maximum length of a write message 503 * @max_read_len: maximum length of a read message 504 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 505 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 506 * 507 * Note about combined messages: Some I2C controllers can only send one message 508 * per transfer, plus something called combined message or write-then-read. 509 * This is (usually) a small write message followed by a read message and 510 * barely enough to access register based devices like EEPROMs. There is a flag 511 * to support this mode. It implies max_num_msg = 2 and does the length checks 512 * with max_comb_*_len because combined message mode usually has its own 513 * limitations. Because of HW implementations, some controllers can actually do 514 * write-then-anything or other variants. To support that, write-then-read has 515 * been broken out into smaller bits like write-first and read-second which can 516 * be combined as needed. 517 */ 518 519 struct i2c_adapter_quirks { 520 u64 flags; 521 int max_num_msgs; 522 u16 max_write_len; 523 u16 max_read_len; 524 u16 max_comb_1st_msg_len; 525 u16 max_comb_2nd_msg_len; 526 }; 527 528 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 529 #define I2C_AQ_COMB BIT(0) 530 /* first combined message must be write */ 531 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 532 /* second combined message must be read */ 533 #define I2C_AQ_COMB_READ_SECOND BIT(2) 534 /* both combined messages must have the same target address */ 535 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 536 /* convenience macro for typical write-then read case */ 537 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 538 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 539 /* clock stretching is not supported */ 540 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 541 542 /* 543 * i2c_adapter is the structure used to identify a physical i2c bus along 544 * with the access algorithms necessary to access it. 545 */ 546 struct i2c_adapter { 547 struct module *owner; 548 unsigned int class; /* classes to allow probing for */ 549 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 550 void *algo_data; 551 552 /* data fields that are valid for all devices */ 553 const struct i2c_lock_operations *lock_ops; 554 struct rt_mutex bus_lock; 555 struct rt_mutex mux_lock; 556 557 int timeout; /* in jiffies */ 558 int retries; 559 struct device dev; /* the adapter device */ 560 561 int nr; 562 char name[48]; 563 struct completion dev_released; 564 565 struct mutex userspace_clients_lock; 566 struct list_head userspace_clients; 567 568 struct i2c_bus_recovery_info *bus_recovery_info; 569 const struct i2c_adapter_quirks *quirks; 570 }; 571 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 572 573 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 574 { 575 return dev_get_drvdata(&dev->dev); 576 } 577 578 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 579 { 580 dev_set_drvdata(&dev->dev, data); 581 } 582 583 static inline struct i2c_adapter * 584 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 585 { 586 #if IS_ENABLED(CONFIG_I2C_MUX) 587 struct device *parent = adapter->dev.parent; 588 589 if (parent != NULL && parent->type == &i2c_adapter_type) 590 return to_i2c_adapter(parent); 591 else 592 #endif 593 return NULL; 594 } 595 596 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 597 598 /* Adapter locking functions, exported for shared pin cases */ 599 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 600 #define I2C_LOCK_SEGMENT BIT(1) 601 602 /** 603 * i2c_lock_bus - Get exclusive access to an I2C bus segment 604 * @adapter: Target I2C bus segment 605 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 606 * locks only this branch in the adapter tree 607 */ 608 static inline void 609 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 610 { 611 adapter->lock_ops->lock_bus(adapter, flags); 612 } 613 614 /** 615 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 616 * @adapter: Target I2C bus segment 617 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 618 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 619 * 620 * Return: true if the I2C bus segment is locked, false otherwise 621 */ 622 static inline int 623 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 624 { 625 return adapter->lock_ops->trylock_bus(adapter, flags); 626 } 627 628 /** 629 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 630 * @adapter: Target I2C bus segment 631 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 632 * unlocks only this branch in the adapter tree 633 */ 634 static inline void 635 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 636 { 637 adapter->lock_ops->unlock_bus(adapter, flags); 638 } 639 640 static inline void 641 i2c_lock_adapter(struct i2c_adapter *adapter) 642 { 643 i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 644 } 645 646 static inline void 647 i2c_unlock_adapter(struct i2c_adapter *adapter) 648 { 649 i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); 650 } 651 652 /*flags for the client struct: */ 653 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 654 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 655 /* Must equal I2C_M_TEN below */ 656 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 657 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 658 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 659 /* Must match I2C_M_STOP|IGNORE_NAK */ 660 661 /* i2c adapter classes (bitmask) */ 662 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 663 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 664 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 665 #define I2C_CLASS_DEPRECATED (1<<8) /* Warn users that adapter will stop using classes */ 666 667 /* Internal numbers to terminate lists */ 668 #define I2C_CLIENT_END 0xfffeU 669 670 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 671 #define I2C_ADDRS(addr, addrs...) \ 672 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 673 674 675 /* ----- functions exported by i2c.o */ 676 677 /* administration... 678 */ 679 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) 680 extern int i2c_add_adapter(struct i2c_adapter *); 681 extern void i2c_del_adapter(struct i2c_adapter *); 682 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 683 684 extern int i2c_register_driver(struct module *, struct i2c_driver *); 685 extern void i2c_del_driver(struct i2c_driver *); 686 687 /* use a define to avoid include chaining to get THIS_MODULE */ 688 #define i2c_add_driver(driver) \ 689 i2c_register_driver(THIS_MODULE, driver) 690 691 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 692 extern void i2c_release_client(struct i2c_client *client); 693 694 /* call the i2c_client->command() of all attached clients with 695 * the given arguments */ 696 extern void i2c_clients_command(struct i2c_adapter *adap, 697 unsigned int cmd, void *arg); 698 699 extern struct i2c_adapter *i2c_get_adapter(int nr); 700 extern void i2c_put_adapter(struct i2c_adapter *adap); 701 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 702 703 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 704 705 /* Return the functionality mask */ 706 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 707 { 708 return adap->algo->functionality(adap); 709 } 710 711 /* Return 1 if adapter supports everything we need, 0 if not. */ 712 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 713 { 714 return (func & i2c_get_functionality(adap)) == func; 715 } 716 717 /** 718 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 719 * @adap: i2c adapter 720 * @quirks: quirk flags 721 * 722 * Return: true if the adapter has all the specified quirk flags, false if not 723 */ 724 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 725 { 726 if (!adap->quirks) 727 return false; 728 return (adap->quirks->flags & quirks) == quirks; 729 } 730 731 /* Return the adapter number for a specific adapter */ 732 static inline int i2c_adapter_id(struct i2c_adapter *adap) 733 { 734 return adap->nr; 735 } 736 737 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 738 { 739 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 740 } 741 742 /** 743 * module_i2c_driver() - Helper macro for registering a modular I2C driver 744 * @__i2c_driver: i2c_driver struct 745 * 746 * Helper macro for I2C drivers which do not do anything special in module 747 * init/exit. This eliminates a lot of boilerplate. Each module may only 748 * use this macro once, and calling it replaces module_init() and module_exit() 749 */ 750 #define module_i2c_driver(__i2c_driver) \ 751 module_driver(__i2c_driver, i2c_add_driver, \ 752 i2c_del_driver) 753 754 /** 755 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 756 * @__i2c_driver: i2c_driver struct 757 * 758 * Helper macro for I2C drivers which do not do anything special in their 759 * init. This eliminates a lot of boilerplate. Each driver may only 760 * use this macro once, and calling it replaces device_initcall(). 761 */ 762 #define builtin_i2c_driver(__i2c_driver) \ 763 builtin_driver(__i2c_driver, i2c_add_driver) 764 765 #endif /* I2C */ 766 767 #if IS_ENABLED(CONFIG_OF) 768 /* must call put_device() when done with returned i2c_client device */ 769 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 770 771 /* must call put_device() when done with returned i2c_adapter device */ 772 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 773 774 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 775 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 776 777 #else 778 779 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 780 { 781 return NULL; 782 } 783 784 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 785 { 786 return NULL; 787 } 788 789 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 790 { 791 return NULL; 792 } 793 #endif /* CONFIG_OF */ 794 795 #if IS_ENABLED(CONFIG_ACPI) 796 u32 i2c_acpi_find_bus_speed(struct device *dev); 797 #else 798 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 799 { 800 return 0; 801 } 802 #endif /* CONFIG_ACPI */ 803 804 #endif /* _LINUX_I2C_H */ 805